Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/locks.c |
| 3 | * |
| 4 | * Provide support for fcntl()'s F_GETLK, F_SETLK, and F_SETLKW calls. |
| 5 | * Doug Evans (dje@spiff.uucp), August 07, 1992 |
| 6 | * |
| 7 | * Deadlock detection added. |
| 8 | * FIXME: one thing isn't handled yet: |
| 9 | * - mandatory locks (requires lots of changes elsewhere) |
| 10 | * Kelly Carmichael (kelly@[142.24.8.65]), September 17, 1994. |
| 11 | * |
| 12 | * Miscellaneous edits, and a total rewrite of posix_lock_file() code. |
| 13 | * Kai Petzke (wpp@marie.physik.tu-berlin.de), 1994 |
| 14 | * |
| 15 | * Converted file_lock_table to a linked list from an array, which eliminates |
| 16 | * the limits on how many active file locks are open. |
| 17 | * Chad Page (pageone@netcom.com), November 27, 1994 |
| 18 | * |
| 19 | * Removed dependency on file descriptors. dup()'ed file descriptors now |
| 20 | * get the same locks as the original file descriptors, and a close() on |
| 21 | * any file descriptor removes ALL the locks on the file for the current |
| 22 | * process. Since locks still depend on the process id, locks are inherited |
| 23 | * after an exec() but not after a fork(). This agrees with POSIX, and both |
| 24 | * BSD and SVR4 practice. |
| 25 | * Andy Walker (andy@lysaker.kvaerner.no), February 14, 1995 |
| 26 | * |
| 27 | * Scrapped free list which is redundant now that we allocate locks |
| 28 | * dynamically with kmalloc()/kfree(). |
| 29 | * Andy Walker (andy@lysaker.kvaerner.no), February 21, 1995 |
| 30 | * |
| 31 | * Implemented two lock personalities - FL_FLOCK and FL_POSIX. |
| 32 | * |
| 33 | * FL_POSIX locks are created with calls to fcntl() and lockf() through the |
| 34 | * fcntl() system call. They have the semantics described above. |
| 35 | * |
| 36 | * FL_FLOCK locks are created with calls to flock(), through the flock() |
| 37 | * system call, which is new. Old C libraries implement flock() via fcntl() |
| 38 | * and will continue to use the old, broken implementation. |
| 39 | * |
| 40 | * FL_FLOCK locks follow the 4.4 BSD flock() semantics. They are associated |
| 41 | * with a file pointer (filp). As a result they can be shared by a parent |
| 42 | * process and its children after a fork(). They are removed when the last |
| 43 | * file descriptor referring to the file pointer is closed (unless explicitly |
| 44 | * unlocked). |
| 45 | * |
| 46 | * FL_FLOCK locks never deadlock, an existing lock is always removed before |
| 47 | * upgrading from shared to exclusive (or vice versa). When this happens |
| 48 | * any processes blocked by the current lock are woken up and allowed to |
| 49 | * run before the new lock is applied. |
| 50 | * Andy Walker (andy@lysaker.kvaerner.no), June 09, 1995 |
| 51 | * |
| 52 | * Removed some race conditions in flock_lock_file(), marked other possible |
| 53 | * races. Just grep for FIXME to see them. |
| 54 | * Dmitry Gorodchanin (pgmdsg@ibi.com), February 09, 1996. |
| 55 | * |
| 56 | * Addressed Dmitry's concerns. Deadlock checking no longer recursive. |
| 57 | * Lock allocation changed to GFP_ATOMIC as we can't afford to sleep |
| 58 | * once we've checked for blocking and deadlocking. |
| 59 | * Andy Walker (andy@lysaker.kvaerner.no), April 03, 1996. |
| 60 | * |
| 61 | * Initial implementation of mandatory locks. SunOS turned out to be |
| 62 | * a rotten model, so I implemented the "obvious" semantics. |
Paul Bolle | 395cf96 | 2011-08-15 02:02:26 +0200 | [diff] [blame] | 63 | * See 'Documentation/filesystems/mandatory-locking.txt' for details. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | * Andy Walker (andy@lysaker.kvaerner.no), April 06, 1996. |
| 65 | * |
| 66 | * Don't allow mandatory locks on mmap()'ed files. Added simple functions to |
| 67 | * check if a file has mandatory locks, used by mmap(), open() and creat() to |
| 68 | * see if system call should be rejected. Ref. HP-UX/SunOS/Solaris Reference |
| 69 | * Manual, Section 2. |
| 70 | * Andy Walker (andy@lysaker.kvaerner.no), April 09, 1996. |
| 71 | * |
| 72 | * Tidied up block list handling. Added '/proc/locks' interface. |
| 73 | * Andy Walker (andy@lysaker.kvaerner.no), April 24, 1996. |
| 74 | * |
| 75 | * Fixed deadlock condition for pathological code that mixes calls to |
| 76 | * flock() and fcntl(). |
| 77 | * Andy Walker (andy@lysaker.kvaerner.no), April 29, 1996. |
| 78 | * |
| 79 | * Allow only one type of locking scheme (FL_POSIX or FL_FLOCK) to be in use |
| 80 | * for a given file at a time. Changed the CONFIG_LOCK_MANDATORY scheme to |
| 81 | * guarantee sensible behaviour in the case where file system modules might |
| 82 | * be compiled with different options than the kernel itself. |
| 83 | * Andy Walker (andy@lysaker.kvaerner.no), May 15, 1996. |
| 84 | * |
| 85 | * Added a couple of missing wake_up() calls. Thanks to Thomas Meckel |
| 86 | * (Thomas.Meckel@mni.fh-giessen.de) for spotting this. |
| 87 | * Andy Walker (andy@lysaker.kvaerner.no), May 15, 1996. |
| 88 | * |
| 89 | * Changed FL_POSIX locks to use the block list in the same way as FL_FLOCK |
| 90 | * locks. Changed process synchronisation to avoid dereferencing locks that |
| 91 | * have already been freed. |
| 92 | * Andy Walker (andy@lysaker.kvaerner.no), Sep 21, 1996. |
| 93 | * |
| 94 | * Made the block list a circular list to minimise searching in the list. |
| 95 | * Andy Walker (andy@lysaker.kvaerner.no), Sep 25, 1996. |
| 96 | * |
| 97 | * Made mandatory locking a mount option. Default is not to allow mandatory |
| 98 | * locking. |
| 99 | * Andy Walker (andy@lysaker.kvaerner.no), Oct 04, 1996. |
| 100 | * |
| 101 | * Some adaptations for NFS support. |
| 102 | * Olaf Kirch (okir@monad.swb.de), Dec 1996, |
| 103 | * |
| 104 | * Fixed /proc/locks interface so that we can't overrun the buffer we are handed. |
| 105 | * Andy Walker (andy@lysaker.kvaerner.no), May 12, 1997. |
| 106 | * |
| 107 | * Use slab allocator instead of kmalloc/kfree. |
| 108 | * Use generic list implementation from <linux/list.h>. |
| 109 | * Sped up posix_locks_deadlock by only considering blocked locks. |
| 110 | * Matthew Wilcox <willy@debian.org>, March, 2000. |
| 111 | * |
| 112 | * Leases and LOCK_MAND |
| 113 | * Matthew Wilcox <willy@debian.org>, June, 2000. |
| 114 | * Stephen Rothwell <sfr@canb.auug.org.au>, June, 2000. |
| 115 | */ |
| 116 | |
| 117 | #include <linux/capability.h> |
| 118 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 119 | #include <linux/fdtable.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | #include <linux/fs.h> |
| 121 | #include <linux/init.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | #include <linux/security.h> |
| 123 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | #include <linux/syscalls.h> |
| 125 | #include <linux/time.h> |
Dipankar Sarma | 4fb3a53 | 2005-09-16 19:28:13 -0700 | [diff] [blame] | 126 | #include <linux/rcupdate.h> |
Vitaliy Gusev | ab1f161 | 2008-01-17 00:07:08 +0000 | [diff] [blame] | 127 | #include <linux/pid_namespace.h> |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 128 | #include <linux/hashtable.h> |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 129 | #include <linux/percpu.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 131 | #define CREATE_TRACE_POINTS |
| 132 | #include <trace/events/filelock.h> |
| 133 | |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 134 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | |
| 136 | #define IS_POSIX(fl) (fl->fl_flags & FL_POSIX) |
| 137 | #define IS_FLOCK(fl) (fl->fl_flags & FL_FLOCK) |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 138 | #define IS_LEASE(fl) (fl->fl_flags & (FL_LEASE|FL_DELEG|FL_LAYOUT)) |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 139 | #define IS_OFDLCK(fl) (fl->fl_flags & FL_OFDLCK) |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame^] | 140 | #define IS_REMOTELCK(fl) (fl->fl_pid <= 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 142 | static inline bool is_remote_lock(struct file *filp) |
| 143 | { |
| 144 | return likely(!(filp->f_path.dentry->d_sb->s_flags & MS_NOREMOTELOCK)); |
| 145 | } |
| 146 | |
J. Bruce Fields | ab83fa4 | 2011-07-26 20:10:51 -0400 | [diff] [blame] | 147 | static bool lease_breaking(struct file_lock *fl) |
| 148 | { |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 149 | return fl->fl_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING); |
| 150 | } |
| 151 | |
| 152 | static int target_leasetype(struct file_lock *fl) |
| 153 | { |
| 154 | if (fl->fl_flags & FL_UNLOCK_PENDING) |
| 155 | return F_UNLCK; |
| 156 | if (fl->fl_flags & FL_DOWNGRADE_PENDING) |
| 157 | return F_RDLCK; |
| 158 | return fl->fl_type; |
J. Bruce Fields | ab83fa4 | 2011-07-26 20:10:51 -0400 | [diff] [blame] | 159 | } |
| 160 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | int leases_enable = 1; |
| 162 | int lease_break_time = 45; |
| 163 | |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 164 | /* |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 165 | * The global file_lock_list is only used for displaying /proc/locks, so we |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 166 | * keep a list on each CPU, with each list protected by its own spinlock. |
| 167 | * Global serialization is done using file_rwsem. |
| 168 | * |
| 169 | * Note that alterations to the list also require that the relevant flc_lock is |
| 170 | * held. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 171 | */ |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 172 | struct file_lock_list_struct { |
| 173 | spinlock_t lock; |
| 174 | struct hlist_head hlist; |
| 175 | }; |
| 176 | static DEFINE_PER_CPU(struct file_lock_list_struct, file_lock_list); |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 177 | DEFINE_STATIC_PERCPU_RWSEM(file_rwsem); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 178 | |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 179 | /* |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 180 | * The blocked_hash is used to find POSIX lock loops for deadlock detection. |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 181 | * It is protected by blocked_lock_lock. |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 182 | * |
| 183 | * We hash locks by lockowner in order to optimize searching for the lock a |
| 184 | * particular lockowner is waiting on. |
| 185 | * |
| 186 | * FIXME: make this value scale via some heuristic? We generally will want more |
| 187 | * buckets when we have more lockowners holding locks, but that's a little |
| 188 | * difficult to determine without knowing what the workload will look like. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 189 | */ |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 190 | #define BLOCKED_HASH_BITS 7 |
| 191 | static DEFINE_HASHTABLE(blocked_hash, BLOCKED_HASH_BITS); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 192 | |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 193 | /* |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 194 | * This lock protects the blocked_hash. Generally, if you're accessing it, you |
| 195 | * want to be holding this lock. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 196 | * |
| 197 | * In addition, it also protects the fl->fl_block list, and the fl->fl_next |
| 198 | * pointer for file_lock structures that are acting as lock requests (in |
| 199 | * contrast to those that are acting as records of acquired locks). |
| 200 | * |
| 201 | * Note that when we acquire this lock in order to change the above fields, |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 202 | * we often hold the flc_lock as well. In certain cases, when reading the fields |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 203 | * protected by this lock, we can skip acquiring it iff we already hold the |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 204 | * flc_lock. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 205 | * |
| 206 | * In particular, adding an entry to the fl_block list requires that you hold |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 207 | * both the flc_lock and the blocked_lock_lock (acquired in that order). |
| 208 | * Deleting an entry from the list however only requires the file_lock_lock. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 209 | */ |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 210 | static DEFINE_SPINLOCK(blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 212 | static struct kmem_cache *flctx_cache __read_mostly; |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 213 | static struct kmem_cache *filelock_cache __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 215 | static struct file_lock_context * |
Jeff Layton | 5c1c669 | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 216 | locks_get_lock_context(struct inode *inode, int type) |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 217 | { |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 218 | struct file_lock_context *ctx; |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 219 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 220 | /* paired with cmpxchg() below */ |
| 221 | ctx = smp_load_acquire(&inode->i_flctx); |
| 222 | if (likely(ctx) || type == F_UNLCK) |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 223 | goto out; |
| 224 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 225 | ctx = kmem_cache_alloc(flctx_cache, GFP_KERNEL); |
| 226 | if (!ctx) |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 227 | goto out; |
| 228 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 229 | spin_lock_init(&ctx->flc_lock); |
| 230 | INIT_LIST_HEAD(&ctx->flc_flock); |
| 231 | INIT_LIST_HEAD(&ctx->flc_posix); |
| 232 | INIT_LIST_HEAD(&ctx->flc_lease); |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 233 | |
| 234 | /* |
| 235 | * Assign the pointer if it's not already assigned. If it is, then |
| 236 | * free the context we just allocated. |
| 237 | */ |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 238 | if (cmpxchg(&inode->i_flctx, NULL, ctx)) { |
| 239 | kmem_cache_free(flctx_cache, ctx); |
| 240 | ctx = smp_load_acquire(&inode->i_flctx); |
| 241 | } |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 242 | out: |
Jeff Layton | 1890910 | 2016-01-06 21:26:10 -0500 | [diff] [blame] | 243 | trace_locks_get_lock_context(inode, type, ctx); |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 244 | return ctx; |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 245 | } |
| 246 | |
Jeff Layton | e24dada | 2016-01-06 21:28:41 -0500 | [diff] [blame] | 247 | static void |
| 248 | locks_dump_ctx_list(struct list_head *list, char *list_type) |
| 249 | { |
| 250 | struct file_lock *fl; |
| 251 | |
| 252 | list_for_each_entry(fl, list, fl_list) { |
| 253 | pr_warn("%s: fl_owner=%p fl_flags=0x%x fl_type=0x%x fl_pid=%u\n", list_type, fl->fl_owner, fl->fl_flags, fl->fl_type, fl->fl_pid); |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | static void |
| 258 | locks_check_ctx_lists(struct inode *inode) |
| 259 | { |
| 260 | struct file_lock_context *ctx = inode->i_flctx; |
| 261 | |
| 262 | if (unlikely(!list_empty(&ctx->flc_flock) || |
| 263 | !list_empty(&ctx->flc_posix) || |
| 264 | !list_empty(&ctx->flc_lease))) { |
| 265 | pr_warn("Leaked locks on dev=0x%x:0x%x ino=0x%lx:\n", |
| 266 | MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev), |
| 267 | inode->i_ino); |
| 268 | locks_dump_ctx_list(&ctx->flc_flock, "FLOCK"); |
| 269 | locks_dump_ctx_list(&ctx->flc_posix, "POSIX"); |
| 270 | locks_dump_ctx_list(&ctx->flc_lease, "LEASE"); |
| 271 | } |
| 272 | } |
| 273 | |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 274 | void |
Jeff Layton | f27a0fe | 2016-01-07 15:08:51 -0500 | [diff] [blame] | 275 | locks_free_lock_context(struct inode *inode) |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 276 | { |
Jeff Layton | f27a0fe | 2016-01-07 15:08:51 -0500 | [diff] [blame] | 277 | struct file_lock_context *ctx = inode->i_flctx; |
| 278 | |
Jeff Layton | e24dada | 2016-01-06 21:28:41 -0500 | [diff] [blame] | 279 | if (unlikely(ctx)) { |
| 280 | locks_check_ctx_lists(inode); |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 281 | kmem_cache_free(flctx_cache, ctx); |
| 282 | } |
| 283 | } |
| 284 | |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 285 | static void locks_init_lock_heads(struct file_lock *fl) |
Miklos Szeredi | a51cb91 | 2011-07-06 12:33:55 +0200 | [diff] [blame] | 286 | { |
Jeff Layton | 139ca04 | 2013-06-21 08:58:17 -0400 | [diff] [blame] | 287 | INIT_HLIST_NODE(&fl->fl_link); |
Jeff Layton | 6dee60f | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 288 | INIT_LIST_HEAD(&fl->fl_list); |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 289 | INIT_LIST_HEAD(&fl->fl_block); |
| 290 | init_waitqueue_head(&fl->fl_wait); |
Miklos Szeredi | a51cb91 | 2011-07-06 12:33:55 +0200 | [diff] [blame] | 291 | } |
| 292 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | /* Allocate an empty lock structure. */ |
Arnd Bergmann | c5b1f0d | 2010-10-27 15:46:08 +0200 | [diff] [blame] | 294 | struct file_lock *locks_alloc_lock(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | { |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 296 | struct file_lock *fl = kmem_cache_zalloc(filelock_cache, GFP_KERNEL); |
Miklos Szeredi | a51cb91 | 2011-07-06 12:33:55 +0200 | [diff] [blame] | 297 | |
| 298 | if (fl) |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 299 | locks_init_lock_heads(fl); |
Miklos Szeredi | a51cb91 | 2011-07-06 12:33:55 +0200 | [diff] [blame] | 300 | |
| 301 | return fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | } |
Arnd Bergmann | c5b1f0d | 2010-10-27 15:46:08 +0200 | [diff] [blame] | 303 | EXPORT_SYMBOL_GPL(locks_alloc_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | |
Felix Blyakher | a9e61e2 | 2009-03-31 15:12:56 -0500 | [diff] [blame] | 305 | void locks_release_private(struct file_lock *fl) |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 306 | { |
| 307 | if (fl->fl_ops) { |
| 308 | if (fl->fl_ops->fl_release_private) |
| 309 | fl->fl_ops->fl_release_private(fl); |
| 310 | fl->fl_ops = NULL; |
| 311 | } |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 312 | |
Kinglong Mee | 5c97d7b | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 313 | if (fl->fl_lmops) { |
Jeff Layton | cae80b3 | 2015-04-03 09:04:04 -0400 | [diff] [blame] | 314 | if (fl->fl_lmops->lm_put_owner) { |
| 315 | fl->fl_lmops->lm_put_owner(fl->fl_owner); |
| 316 | fl->fl_owner = NULL; |
| 317 | } |
Kinglong Mee | 5c97d7b | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 318 | fl->fl_lmops = NULL; |
| 319 | } |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 320 | } |
Felix Blyakher | a9e61e2 | 2009-03-31 15:12:56 -0500 | [diff] [blame] | 321 | EXPORT_SYMBOL_GPL(locks_release_private); |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 322 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | /* Free a lock which is not in use. */ |
J. Bruce Fields | 05fa313 | 2010-10-30 17:31:15 -0400 | [diff] [blame] | 324 | void locks_free_lock(struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | { |
Miklos Szeredi | 5ce2964 | 2006-03-31 02:30:29 -0800 | [diff] [blame] | 326 | BUG_ON(waitqueue_active(&fl->fl_wait)); |
Jeff Layton | 6dee60f | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 327 | BUG_ON(!list_empty(&fl->fl_list)); |
Miklos Szeredi | 5ce2964 | 2006-03-31 02:30:29 -0800 | [diff] [blame] | 328 | BUG_ON(!list_empty(&fl->fl_block)); |
Jeff Layton | 139ca04 | 2013-06-21 08:58:17 -0400 | [diff] [blame] | 329 | BUG_ON(!hlist_unhashed(&fl->fl_link)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 331 | locks_release_private(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | kmem_cache_free(filelock_cache, fl); |
| 333 | } |
J. Bruce Fields | 05fa313 | 2010-10-30 17:31:15 -0400 | [diff] [blame] | 334 | EXPORT_SYMBOL(locks_free_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 336 | static void |
| 337 | locks_dispose_list(struct list_head *dispose) |
| 338 | { |
| 339 | struct file_lock *fl; |
| 340 | |
| 341 | while (!list_empty(dispose)) { |
Jeff Layton | 6dee60f | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 342 | fl = list_first_entry(dispose, struct file_lock, fl_list); |
| 343 | list_del_init(&fl->fl_list); |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 344 | locks_free_lock(fl); |
| 345 | } |
| 346 | } |
| 347 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | void locks_init_lock(struct file_lock *fl) |
| 349 | { |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 350 | memset(fl, 0, sizeof(struct file_lock)); |
| 351 | locks_init_lock_heads(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | } |
| 353 | |
| 354 | EXPORT_SYMBOL(locks_init_lock); |
| 355 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | /* |
| 357 | * Initialize a new lock from an existing file_lock structure. |
| 358 | */ |
Kinglong Mee | 3fe0fff1 | 2014-08-22 10:18:42 -0400 | [diff] [blame] | 359 | void locks_copy_conflock(struct file_lock *new, struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | { |
| 361 | new->fl_owner = fl->fl_owner; |
| 362 | new->fl_pid = fl->fl_pid; |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 363 | new->fl_file = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | new->fl_flags = fl->fl_flags; |
| 365 | new->fl_type = fl->fl_type; |
| 366 | new->fl_start = fl->fl_start; |
| 367 | new->fl_end = fl->fl_end; |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 368 | new->fl_lmops = fl->fl_lmops; |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 369 | new->fl_ops = NULL; |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 370 | |
| 371 | if (fl->fl_lmops) { |
| 372 | if (fl->fl_lmops->lm_get_owner) |
Jeff Layton | cae80b3 | 2015-04-03 09:04:04 -0400 | [diff] [blame] | 373 | fl->fl_lmops->lm_get_owner(fl->fl_owner); |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 374 | } |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 375 | } |
Kinglong Mee | 3fe0fff1 | 2014-08-22 10:18:42 -0400 | [diff] [blame] | 376 | EXPORT_SYMBOL(locks_copy_conflock); |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 377 | |
| 378 | void locks_copy_lock(struct file_lock *new, struct file_lock *fl) |
| 379 | { |
Jeff Layton | 566709b | 2014-08-11 14:09:35 -0400 | [diff] [blame] | 380 | /* "new" must be a freshly-initialized lock */ |
| 381 | WARN_ON_ONCE(new->fl_ops); |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 382 | |
Kinglong Mee | 3fe0fff1 | 2014-08-22 10:18:42 -0400 | [diff] [blame] | 383 | locks_copy_conflock(new, fl); |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 384 | |
Trond Myklebust | 0996905 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 385 | new->fl_file = fl->fl_file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | new->fl_ops = fl->fl_ops; |
Trond Myklebust | 47831f3 | 2006-03-20 13:44:05 -0500 | [diff] [blame] | 387 | |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 388 | if (fl->fl_ops) { |
| 389 | if (fl->fl_ops->fl_copy_lock) |
| 390 | fl->fl_ops->fl_copy_lock(new, fl); |
| 391 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | } |
| 393 | |
| 394 | EXPORT_SYMBOL(locks_copy_lock); |
| 395 | |
| 396 | static inline int flock_translate_cmd(int cmd) { |
| 397 | if (cmd & LOCK_MAND) |
| 398 | return cmd & (LOCK_MAND | LOCK_RW); |
| 399 | switch (cmd) { |
| 400 | case LOCK_SH: |
| 401 | return F_RDLCK; |
| 402 | case LOCK_EX: |
| 403 | return F_WRLCK; |
| 404 | case LOCK_UN: |
| 405 | return F_UNLCK; |
| 406 | } |
| 407 | return -EINVAL; |
| 408 | } |
| 409 | |
| 410 | /* Fill in a file_lock structure with an appropriate FLOCK lock. */ |
Jeff Layton | 6e129d00 | 2014-09-04 10:25:06 -0400 | [diff] [blame] | 411 | static struct file_lock * |
| 412 | flock_make_lock(struct file *filp, unsigned int cmd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | { |
| 414 | struct file_lock *fl; |
| 415 | int type = flock_translate_cmd(cmd); |
Jeff Layton | 6e129d00 | 2014-09-04 10:25:06 -0400 | [diff] [blame] | 416 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | if (type < 0) |
Jeff Layton | 6e129d00 | 2014-09-04 10:25:06 -0400 | [diff] [blame] | 418 | return ERR_PTR(type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | |
| 420 | fl = locks_alloc_lock(); |
| 421 | if (fl == NULL) |
Jeff Layton | 6e129d00 | 2014-09-04 10:25:06 -0400 | [diff] [blame] | 422 | return ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | |
| 424 | fl->fl_file = filp; |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 425 | fl->fl_owner = filp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | fl->fl_pid = current->tgid; |
| 427 | fl->fl_flags = FL_FLOCK; |
| 428 | fl->fl_type = type; |
| 429 | fl->fl_end = OFFSET_MAX; |
| 430 | |
Jeff Layton | 6e129d00 | 2014-09-04 10:25:06 -0400 | [diff] [blame] | 431 | return fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | } |
| 433 | |
J. Bruce Fields | 0ec4f43 | 2012-07-23 15:17:17 -0400 | [diff] [blame] | 434 | static int assign_type(struct file_lock *fl, long type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | { |
| 436 | switch (type) { |
| 437 | case F_RDLCK: |
| 438 | case F_WRLCK: |
| 439 | case F_UNLCK: |
| 440 | fl->fl_type = type; |
| 441 | break; |
| 442 | default: |
| 443 | return -EINVAL; |
| 444 | } |
| 445 | return 0; |
| 446 | } |
| 447 | |
J. Bruce Fields | ef12e72 | 2014-02-03 12:13:08 -0500 | [diff] [blame] | 448 | static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl, |
| 449 | struct flock64 *l) |
| 450 | { |
| 451 | switch (l->l_whence) { |
| 452 | case SEEK_SET: |
| 453 | fl->fl_start = 0; |
| 454 | break; |
| 455 | case SEEK_CUR: |
| 456 | fl->fl_start = filp->f_pos; |
| 457 | break; |
| 458 | case SEEK_END: |
| 459 | fl->fl_start = i_size_read(file_inode(filp)); |
| 460 | break; |
| 461 | default: |
| 462 | return -EINVAL; |
| 463 | } |
| 464 | if (l->l_start > OFFSET_MAX - fl->fl_start) |
| 465 | return -EOVERFLOW; |
| 466 | fl->fl_start += l->l_start; |
| 467 | if (fl->fl_start < 0) |
| 468 | return -EINVAL; |
| 469 | |
| 470 | /* POSIX-1996 leaves the case l->l_len < 0 undefined; |
| 471 | POSIX-2001 defines it. */ |
| 472 | if (l->l_len > 0) { |
| 473 | if (l->l_len - 1 > OFFSET_MAX - fl->fl_start) |
| 474 | return -EOVERFLOW; |
| 475 | fl->fl_end = fl->fl_start + l->l_len - 1; |
| 476 | |
| 477 | } else if (l->l_len < 0) { |
| 478 | if (fl->fl_start + l->l_len < 0) |
| 479 | return -EINVAL; |
| 480 | fl->fl_end = fl->fl_start - 1; |
| 481 | fl->fl_start += l->l_len; |
| 482 | } else |
| 483 | fl->fl_end = OFFSET_MAX; |
| 484 | |
| 485 | fl->fl_owner = current->files; |
| 486 | fl->fl_pid = current->tgid; |
| 487 | fl->fl_file = filp; |
| 488 | fl->fl_flags = FL_POSIX; |
| 489 | fl->fl_ops = NULL; |
| 490 | fl->fl_lmops = NULL; |
| 491 | |
| 492 | return assign_type(fl, l->l_type); |
| 493 | } |
| 494 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | /* Verify a "struct flock" and copy it to a "struct file_lock" as a POSIX |
| 496 | * style lock. |
| 497 | */ |
| 498 | static int flock_to_posix_lock(struct file *filp, struct file_lock *fl, |
| 499 | struct flock *l) |
| 500 | { |
J. Bruce Fields | ef12e72 | 2014-02-03 12:13:08 -0500 | [diff] [blame] | 501 | struct flock64 ll = { |
| 502 | .l_type = l->l_type, |
| 503 | .l_whence = l->l_whence, |
| 504 | .l_start = l->l_start, |
| 505 | .l_len = l->l_len, |
| 506 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | |
J. Bruce Fields | ef12e72 | 2014-02-03 12:13:08 -0500 | [diff] [blame] | 508 | return flock64_to_posix_lock(filp, fl, &ll); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | } |
| 510 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 511 | /* default lease lock manager operations */ |
Jeff Layton | 4d01b7f | 2014-09-01 15:06:54 -0400 | [diff] [blame] | 512 | static bool |
| 513 | lease_break_callback(struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | { |
| 515 | kill_fasync(&fl->fl_fasync, SIGIO, POLL_MSG); |
Jeff Layton | 4d01b7f | 2014-09-01 15:06:54 -0400 | [diff] [blame] | 516 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | } |
| 518 | |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 519 | static void |
| 520 | lease_setup(struct file_lock *fl, void **priv) |
| 521 | { |
| 522 | struct file *filp = fl->fl_file; |
| 523 | struct fasync_struct *fa = *priv; |
| 524 | |
| 525 | /* |
| 526 | * fasync_insert_entry() returns the old entry if any. If there was no |
| 527 | * old entry, then it used "priv" and inserted it into the fasync list. |
| 528 | * Clear the pointer to indicate that it shouldn't be freed. |
| 529 | */ |
| 530 | if (!fasync_insert_entry(fa->fa_fd, filp, &fl->fl_fasync, fa)) |
| 531 | *priv = NULL; |
| 532 | |
| 533 | __f_setown(filp, task_pid(current), PIDTYPE_PID, 0); |
| 534 | } |
| 535 | |
Alexey Dobriyan | 7b02196 | 2009-09-21 17:01:12 -0700 | [diff] [blame] | 536 | static const struct lock_manager_operations lease_manager_ops = { |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 537 | .lm_break = lease_break_callback, |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 538 | .lm_change = lease_modify, |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 539 | .lm_setup = lease_setup, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 540 | }; |
| 541 | |
| 542 | /* |
| 543 | * Initialize a lease, use the default lock manager operations |
| 544 | */ |
J. Bruce Fields | 0ec4f43 | 2012-07-23 15:17:17 -0400 | [diff] [blame] | 545 | static int lease_init(struct file *filp, long type, struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | { |
Trond Myklebust | 75dff55 | 2006-05-07 23:02:42 -0400 | [diff] [blame] | 547 | if (assign_type(fl, type) != 0) |
| 548 | return -EINVAL; |
| 549 | |
Jeff Layton | 7ca7631 | 2014-09-01 19:04:48 -0400 | [diff] [blame] | 550 | fl->fl_owner = filp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | fl->fl_pid = current->tgid; |
| 552 | |
| 553 | fl->fl_file = filp; |
| 554 | fl->fl_flags = FL_LEASE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | fl->fl_start = 0; |
| 556 | fl->fl_end = OFFSET_MAX; |
| 557 | fl->fl_ops = NULL; |
| 558 | fl->fl_lmops = &lease_manager_ops; |
| 559 | return 0; |
| 560 | } |
| 561 | |
| 562 | /* Allocate a file_lock initialised to this type of lease */ |
J. Bruce Fields | 0ec4f43 | 2012-07-23 15:17:17 -0400 | [diff] [blame] | 563 | static struct file_lock *lease_alloc(struct file *filp, long type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | { |
| 565 | struct file_lock *fl = locks_alloc_lock(); |
Trond Myklebust | 75dff55 | 2006-05-07 23:02:42 -0400 | [diff] [blame] | 566 | int error = -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | |
| 568 | if (fl == NULL) |
J. Bruce Fields | e32b8ee | 2007-03-01 14:34:35 -0500 | [diff] [blame] | 569 | return ERR_PTR(error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | |
| 571 | error = lease_init(filp, type, fl); |
Trond Myklebust | 75dff55 | 2006-05-07 23:02:42 -0400 | [diff] [blame] | 572 | if (error) { |
| 573 | locks_free_lock(fl); |
J. Bruce Fields | e32b8ee | 2007-03-01 14:34:35 -0500 | [diff] [blame] | 574 | return ERR_PTR(error); |
Trond Myklebust | 75dff55 | 2006-05-07 23:02:42 -0400 | [diff] [blame] | 575 | } |
J. Bruce Fields | e32b8ee | 2007-03-01 14:34:35 -0500 | [diff] [blame] | 576 | return fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | } |
| 578 | |
| 579 | /* Check if two locks overlap each other. |
| 580 | */ |
| 581 | static inline int locks_overlap(struct file_lock *fl1, struct file_lock *fl2) |
| 582 | { |
| 583 | return ((fl1->fl_end >= fl2->fl_start) && |
| 584 | (fl2->fl_end >= fl1->fl_start)); |
| 585 | } |
| 586 | |
| 587 | /* |
| 588 | * Check whether two locks have the same owner. |
| 589 | */ |
Matt Mackall | 33443c4 | 2006-01-08 01:05:22 -0800 | [diff] [blame] | 590 | static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | { |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 592 | if (fl1->fl_lmops && fl1->fl_lmops->lm_compare_owner) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | return fl2->fl_lmops == fl1->fl_lmops && |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 594 | fl1->fl_lmops->lm_compare_owner(fl1, fl2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 595 | return fl1->fl_owner == fl2->fl_owner; |
| 596 | } |
| 597 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 598 | /* Must be called with the flc_lock held! */ |
Jeff Layton | 6ca10ed | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 599 | static void locks_insert_global_locks(struct file_lock *fl) |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 600 | { |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 601 | struct file_lock_list_struct *fll = this_cpu_ptr(&file_lock_list); |
| 602 | |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 603 | percpu_rwsem_assert_held(&file_rwsem); |
| 604 | |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 605 | spin_lock(&fll->lock); |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 606 | fl->fl_link_cpu = smp_processor_id(); |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 607 | hlist_add_head(&fl->fl_link, &fll->hlist); |
| 608 | spin_unlock(&fll->lock); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 609 | } |
| 610 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 611 | /* Must be called with the flc_lock held! */ |
Jeff Layton | 6ca10ed | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 612 | static void locks_delete_global_locks(struct file_lock *fl) |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 613 | { |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 614 | struct file_lock_list_struct *fll; |
| 615 | |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 616 | percpu_rwsem_assert_held(&file_rwsem); |
| 617 | |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 618 | /* |
| 619 | * Avoid taking lock if already unhashed. This is safe since this check |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 620 | * is done while holding the flc_lock, and new insertions into the list |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 621 | * also require that it be held. |
| 622 | */ |
| 623 | if (hlist_unhashed(&fl->fl_link)) |
| 624 | return; |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 625 | |
| 626 | fll = per_cpu_ptr(&file_lock_list, fl->fl_link_cpu); |
| 627 | spin_lock(&fll->lock); |
Jeff Layton | 139ca04 | 2013-06-21 08:58:17 -0400 | [diff] [blame] | 628 | hlist_del_init(&fl->fl_link); |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 629 | spin_unlock(&fll->lock); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 630 | } |
| 631 | |
Jeff Layton | 3999e49 | 2013-06-21 08:58:19 -0400 | [diff] [blame] | 632 | static unsigned long |
| 633 | posix_owner_key(struct file_lock *fl) |
| 634 | { |
| 635 | if (fl->fl_lmops && fl->fl_lmops->lm_owner_key) |
| 636 | return fl->fl_lmops->lm_owner_key(fl); |
| 637 | return (unsigned long)fl->fl_owner; |
| 638 | } |
| 639 | |
Jeff Layton | 6ca10ed | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 640 | static void locks_insert_global_blocked(struct file_lock *waiter) |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 641 | { |
Daniel Wagner | 663d5af | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 642 | lockdep_assert_held(&blocked_lock_lock); |
| 643 | |
Jeff Layton | 3999e49 | 2013-06-21 08:58:19 -0400 | [diff] [blame] | 644 | hash_add(blocked_hash, &waiter->fl_link, posix_owner_key(waiter)); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 645 | } |
| 646 | |
Jeff Layton | 6ca10ed | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 647 | static void locks_delete_global_blocked(struct file_lock *waiter) |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 648 | { |
Daniel Wagner | 663d5af | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 649 | lockdep_assert_held(&blocked_lock_lock); |
| 650 | |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 651 | hash_del(&waiter->fl_link); |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 652 | } |
| 653 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 654 | /* Remove waiter from blocker's block list. |
| 655 | * When blocker ends up pointing to itself then the list is empty. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 656 | * |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 657 | * Must be called with blocked_lock_lock held. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 658 | */ |
Matt Mackall | 33443c4 | 2006-01-08 01:05:22 -0800 | [diff] [blame] | 659 | static void __locks_delete_block(struct file_lock *waiter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | { |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 661 | locks_delete_global_blocked(waiter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | list_del_init(&waiter->fl_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | waiter->fl_next = NULL; |
| 664 | } |
| 665 | |
Jeff Layton | 1a9e64a | 2013-06-21 08:58:10 -0400 | [diff] [blame] | 666 | static void locks_delete_block(struct file_lock *waiter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | { |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 668 | spin_lock(&blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | __locks_delete_block(waiter); |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 670 | spin_unlock(&blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | } |
| 672 | |
| 673 | /* Insert waiter into blocker's block list. |
| 674 | * We use a circular list so that processes can be easily woken up in |
| 675 | * the order they blocked. The documentation doesn't require this but |
| 676 | * it seems like the reasonable thing to do. |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 677 | * |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 678 | * Must be called with both the flc_lock and blocked_lock_lock held. The |
| 679 | * fl_block list itself is protected by the blocked_lock_lock, but by ensuring |
| 680 | * that the flc_lock is also held on insertions we can avoid taking the |
| 681 | * blocked_lock_lock in some cases when we see that the fl_block list is empty. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | */ |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 683 | static void __locks_insert_block(struct file_lock *blocker, |
| 684 | struct file_lock *waiter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | { |
J. Bruce Fields | 6dc0fe8 | 2006-03-26 01:37:24 -0800 | [diff] [blame] | 686 | BUG_ON(!list_empty(&waiter->fl_block)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | waiter->fl_next = blocker; |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 688 | list_add_tail(&waiter->fl_block, &blocker->fl_block); |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 689 | if (IS_POSIX(blocker) && !IS_OFDLCK(blocker)) |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 690 | locks_insert_global_blocked(waiter); |
| 691 | } |
| 692 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 693 | /* Must be called with flc_lock held. */ |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 694 | static void locks_insert_block(struct file_lock *blocker, |
| 695 | struct file_lock *waiter) |
| 696 | { |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 697 | spin_lock(&blocked_lock_lock); |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 698 | __locks_insert_block(blocker, waiter); |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 699 | spin_unlock(&blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | } |
| 701 | |
Jeff Layton | 1cb3601 | 2013-06-21 08:58:12 -0400 | [diff] [blame] | 702 | /* |
| 703 | * Wake up processes blocked waiting for blocker. |
| 704 | * |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 705 | * Must be called with the inode->flc_lock held! |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | */ |
| 707 | static void locks_wake_up_blocks(struct file_lock *blocker) |
| 708 | { |
Jeff Layton | 4e8c765 | 2013-06-21 08:58:16 -0400 | [diff] [blame] | 709 | /* |
| 710 | * Avoid taking global lock if list is empty. This is safe since new |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 711 | * blocked requests are only added to the list under the flc_lock, and |
| 712 | * the flc_lock is always held here. Note that removal from the fl_block |
| 713 | * list does not require the flc_lock, so we must recheck list_empty() |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 714 | * after acquiring the blocked_lock_lock. |
Jeff Layton | 4e8c765 | 2013-06-21 08:58:16 -0400 | [diff] [blame] | 715 | */ |
| 716 | if (list_empty(&blocker->fl_block)) |
| 717 | return; |
| 718 | |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 719 | spin_lock(&blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | while (!list_empty(&blocker->fl_block)) { |
Pavel Emelyanov | f0c1cd0 | 2007-09-19 16:44:07 +0400 | [diff] [blame] | 721 | struct file_lock *waiter; |
| 722 | |
| 723 | waiter = list_first_entry(&blocker->fl_block, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | struct file_lock, fl_block); |
| 725 | __locks_delete_block(waiter); |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 726 | if (waiter->fl_lmops && waiter->fl_lmops->lm_notify) |
| 727 | waiter->fl_lmops->lm_notify(waiter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | else |
| 729 | wake_up(&waiter->fl_wait); |
| 730 | } |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 731 | spin_unlock(&blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | } |
| 733 | |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 734 | static void |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 735 | locks_insert_lock_ctx(struct file_lock *fl, struct list_head *before) |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 736 | { |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 737 | list_add_tail(&fl->fl_list, before); |
| 738 | locks_insert_global_locks(fl); |
| 739 | } |
| 740 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 741 | static void |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 742 | locks_unlink_lock_ctx(struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | { |
Jeff Layton | 8897469 | 2013-06-21 08:58:14 -0400 | [diff] [blame] | 744 | locks_delete_global_locks(fl); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 745 | list_del_init(&fl->fl_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | locks_wake_up_blocks(fl); |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 747 | } |
| 748 | |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 749 | static void |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 750 | locks_delete_lock_ctx(struct file_lock *fl, struct list_head *dispose) |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 751 | { |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 752 | locks_unlink_lock_ctx(fl); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 753 | if (dispose) |
| 754 | list_add(&fl->fl_list, dispose); |
| 755 | else |
| 756 | locks_free_lock(fl); |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 757 | } |
| 758 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | /* Determine if lock sys_fl blocks lock caller_fl. Common functionality |
| 760 | * checks for shared/exclusive status of overlapping locks. |
| 761 | */ |
| 762 | static int locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) |
| 763 | { |
| 764 | if (sys_fl->fl_type == F_WRLCK) |
| 765 | return 1; |
| 766 | if (caller_fl->fl_type == F_WRLCK) |
| 767 | return 1; |
| 768 | return 0; |
| 769 | } |
| 770 | |
| 771 | /* Determine if lock sys_fl blocks lock caller_fl. POSIX specific |
| 772 | * checking before calling the locks_conflict(). |
| 773 | */ |
| 774 | static int posix_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) |
| 775 | { |
| 776 | /* POSIX locks owned by the same process do not conflict with |
| 777 | * each other. |
| 778 | */ |
Jeff Layton | 9b8c869 | 2015-04-03 09:04:02 -0400 | [diff] [blame] | 779 | if (posix_same_owner(caller_fl, sys_fl)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | return (0); |
| 781 | |
| 782 | /* Check whether they overlap */ |
| 783 | if (!locks_overlap(caller_fl, sys_fl)) |
| 784 | return 0; |
| 785 | |
| 786 | return (locks_conflict(caller_fl, sys_fl)); |
| 787 | } |
| 788 | |
| 789 | /* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific |
| 790 | * checking before calling the locks_conflict(). |
| 791 | */ |
| 792 | static int flock_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) |
| 793 | { |
| 794 | /* FLOCK locks referring to the same filp do not conflict with |
| 795 | * each other. |
| 796 | */ |
Jeff Layton | 9b8c869 | 2015-04-03 09:04:02 -0400 | [diff] [blame] | 797 | if (caller_fl->fl_file == sys_fl->fl_file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | return (0); |
| 799 | if ((caller_fl->fl_type & LOCK_MAND) || (sys_fl->fl_type & LOCK_MAND)) |
| 800 | return 0; |
| 801 | |
| 802 | return (locks_conflict(caller_fl, sys_fl)); |
| 803 | } |
| 804 | |
J. Bruce Fields | 6d34ac1 | 2007-05-11 16:09:32 -0400 | [diff] [blame] | 805 | void |
Marc Eshel | 9d6a8c5 | 2007-02-21 00:55:18 -0500 | [diff] [blame] | 806 | posix_test_lock(struct file *filp, struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | { |
| 808 | struct file_lock *cfl; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 809 | struct file_lock_context *ctx; |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 810 | struct inode *inode = locks_inode(filp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 811 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 812 | ctx = smp_load_acquire(&inode->i_flctx); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 813 | if (!ctx || list_empty_careful(&ctx->flc_posix)) { |
J. Bruce Fields | 129a84d | 2007-05-10 18:38:43 -0400 | [diff] [blame] | 814 | fl->fl_type = F_UNLCK; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 815 | return; |
| 816 | } |
| 817 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 818 | spin_lock(&ctx->flc_lock); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 819 | list_for_each_entry(cfl, &ctx->flc_posix, fl_list) { |
| 820 | if (posix_locks_conflict(fl, cfl)) { |
| 821 | locks_copy_conflock(fl, cfl); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 822 | goto out; |
| 823 | } |
| 824 | } |
| 825 | fl->fl_type = F_UNLCK; |
| 826 | out: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 827 | spin_unlock(&ctx->flc_lock); |
J. Bruce Fields | 6d34ac1 | 2007-05-11 16:09:32 -0400 | [diff] [blame] | 828 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | EXPORT_SYMBOL(posix_test_lock); |
| 831 | |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 832 | /* |
| 833 | * Deadlock detection: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 834 | * |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 835 | * We attempt to detect deadlocks that are due purely to posix file |
| 836 | * locks. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | * |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 838 | * We assume that a task can be waiting for at most one lock at a time. |
| 839 | * So for any acquired lock, the process holding that lock may be |
| 840 | * waiting on at most one other lock. That lock in turns may be held by |
| 841 | * someone waiting for at most one other lock. Given a requested lock |
| 842 | * caller_fl which is about to wait for a conflicting lock block_fl, we |
| 843 | * follow this chain of waiters to ensure we are not about to create a |
| 844 | * cycle. |
J. Bruce Fields | 97855b4 | 2007-10-30 11:20:02 -0400 | [diff] [blame] | 845 | * |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 846 | * Since we do this before we ever put a process to sleep on a lock, we |
| 847 | * are ensured that there is never a cycle; that is what guarantees that |
| 848 | * the while() loop in posix_locks_deadlock() eventually completes. |
| 849 | * |
| 850 | * Note: the above assumption may not be true when handling lock |
| 851 | * requests from a broken NFS client. It may also fail in the presence |
| 852 | * of tasks (such as posix threads) sharing the same open file table. |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 853 | * To handle those cases, we just bail out after a few iterations. |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 854 | * |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 855 | * For FL_OFDLCK locks, the owner is the filp, not the files_struct. |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 856 | * Because the owner is not even nominally tied to a thread of |
| 857 | * execution, the deadlock detection below can't reasonably work well. Just |
| 858 | * skip it for those. |
| 859 | * |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 860 | * In principle, we could do a more limited deadlock detection on FL_OFDLCK |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 861 | * locks that just checks for the case where two tasks are attempting to |
| 862 | * upgrade from read to write locks on the same inode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 863 | */ |
J. Bruce Fields | 97855b4 | 2007-10-30 11:20:02 -0400 | [diff] [blame] | 864 | |
| 865 | #define MAX_DEADLK_ITERATIONS 10 |
| 866 | |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 867 | /* Find a lock that the owner of the given block_fl is blocking on. */ |
| 868 | static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl) |
| 869 | { |
| 870 | struct file_lock *fl; |
| 871 | |
Jeff Layton | 3999e49 | 2013-06-21 08:58:19 -0400 | [diff] [blame] | 872 | hash_for_each_possible(blocked_hash, fl, fl_link, posix_owner_key(block_fl)) { |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 873 | if (posix_same_owner(fl, block_fl)) |
| 874 | return fl->fl_next; |
| 875 | } |
| 876 | return NULL; |
| 877 | } |
| 878 | |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 879 | /* Must be called with the blocked_lock_lock held! */ |
Adrian Bunk | b0904e1 | 2006-06-23 02:05:13 -0700 | [diff] [blame] | 880 | static int posix_locks_deadlock(struct file_lock *caller_fl, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | struct file_lock *block_fl) |
| 882 | { |
J. Bruce Fields | 97855b4 | 2007-10-30 11:20:02 -0400 | [diff] [blame] | 883 | int i = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | |
Daniel Wagner | 663d5af | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 885 | lockdep_assert_held(&blocked_lock_lock); |
| 886 | |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 887 | /* |
| 888 | * This deadlock detector can't reasonably detect deadlocks with |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 889 | * FL_OFDLCK locks, since they aren't owned by a process, per-se. |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 890 | */ |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 891 | if (IS_OFDLCK(caller_fl)) |
Jeff Layton | 57b6532 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 892 | return 0; |
| 893 | |
J. Bruce Fields | b533184 | 2007-10-26 18:05:40 -0400 | [diff] [blame] | 894 | while ((block_fl = what_owner_is_waiting_for(block_fl))) { |
| 895 | if (i++ > MAX_DEADLK_ITERATIONS) |
| 896 | return 0; |
| 897 | if (posix_same_owner(caller_fl, block_fl)) |
| 898 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 899 | } |
| 900 | return 0; |
| 901 | } |
| 902 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | /* Try to create a FLOCK lock on filp. We always insert new FLOCK locks |
J. Bruce Fields | 02888f4 | 2007-09-12 15:45:07 -0400 | [diff] [blame] | 904 | * after any leases, but before any posix locks. |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 905 | * |
| 906 | * Note that if called with an FL_EXISTS argument, the caller may determine |
| 907 | * whether or not a lock was successfully freed by testing the return |
| 908 | * value for -ENOENT. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 909 | */ |
Jeff Layton | bcd7f78 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 910 | static int flock_lock_inode(struct inode *inode, struct file_lock *request) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | { |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 912 | struct file_lock *new_fl = NULL; |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 913 | struct file_lock *fl; |
| 914 | struct file_lock_context *ctx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 915 | int error = 0; |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 916 | bool found = false; |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 917 | LIST_HEAD(dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 918 | |
Jeff Layton | 5c1c669 | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 919 | ctx = locks_get_lock_context(inode, request->fl_type); |
| 920 | if (!ctx) { |
| 921 | if (request->fl_type != F_UNLCK) |
| 922 | return -ENOMEM; |
| 923 | return (request->fl_flags & FL_EXISTS) ? -ENOENT : 0; |
| 924 | } |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 925 | |
Arnd Bergmann | b89f432 | 2010-09-18 15:09:31 +0200 | [diff] [blame] | 926 | if (!(request->fl_flags & FL_ACCESS) && (request->fl_type != F_UNLCK)) { |
| 927 | new_fl = locks_alloc_lock(); |
| 928 | if (!new_fl) |
| 929 | return -ENOMEM; |
| 930 | } |
| 931 | |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 932 | percpu_down_read_preempt_disable(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 933 | spin_lock(&ctx->flc_lock); |
Trond Myklebust | f07f18d | 2006-06-29 16:38:37 -0400 | [diff] [blame] | 934 | if (request->fl_flags & FL_ACCESS) |
| 935 | goto find_conflict; |
Pavel Emelyanov | 84d535a | 2007-09-11 16:38:13 +0400 | [diff] [blame] | 936 | |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 937 | list_for_each_entry(fl, &ctx->flc_flock, fl_list) { |
Jeff Layton | bcd7f78 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 938 | if (request->fl_file != fl->fl_file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 939 | continue; |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 940 | if (request->fl_type == fl->fl_type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 941 | goto out; |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 942 | found = true; |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 943 | locks_delete_lock_ctx(fl, &dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 944 | break; |
| 945 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 947 | if (request->fl_type == F_UNLCK) { |
| 948 | if ((request->fl_flags & FL_EXISTS) && !found) |
| 949 | error = -ENOENT; |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 950 | goto out; |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 951 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 952 | |
Trond Myklebust | f07f18d | 2006-06-29 16:38:37 -0400 | [diff] [blame] | 953 | find_conflict: |
Jeff Layton | 5263e31 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 954 | list_for_each_entry(fl, &ctx->flc_flock, fl_list) { |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 955 | if (!flock_locks_conflict(request, fl)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 956 | continue; |
| 957 | error = -EAGAIN; |
Miklos Szeredi | bde74e4 | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 958 | if (!(request->fl_flags & FL_SLEEP)) |
| 959 | goto out; |
| 960 | error = FILE_LOCK_DEFERRED; |
| 961 | locks_insert_block(fl, request); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 962 | goto out; |
| 963 | } |
Trond Myklebust | f07f18d | 2006-06-29 16:38:37 -0400 | [diff] [blame] | 964 | if (request->fl_flags & FL_ACCESS) |
| 965 | goto out; |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 966 | locks_copy_lock(new_fl, request); |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 967 | locks_insert_lock_ctx(new_fl, &ctx->flc_flock); |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 968 | new_fl = NULL; |
Kirill Korotaev | 9cedc19 | 2006-06-14 17:59:35 +0400 | [diff] [blame] | 969 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 970 | |
| 971 | out: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 972 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 973 | percpu_up_read_preempt_enable(&file_rwsem); |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 974 | if (new_fl) |
| 975 | locks_free_lock(new_fl); |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 976 | locks_dispose_list(&dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 977 | return error; |
| 978 | } |
| 979 | |
Jeff Layton | b4d629a | 2016-01-07 18:27:42 -0500 | [diff] [blame] | 980 | static int posix_lock_inode(struct inode *inode, struct file_lock *request, |
| 981 | struct file_lock *conflock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 982 | { |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 983 | struct file_lock *fl, *tmp; |
Miklos Szeredi | 39005d0 | 2006-06-23 02:05:10 -0700 | [diff] [blame] | 984 | struct file_lock *new_fl = NULL; |
| 985 | struct file_lock *new_fl2 = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 986 | struct file_lock *left = NULL; |
| 987 | struct file_lock *right = NULL; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 988 | struct file_lock_context *ctx; |
Jeff Layton | b9746ef | 2013-06-21 08:58:13 -0400 | [diff] [blame] | 989 | int error; |
| 990 | bool added = false; |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 991 | LIST_HEAD(dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | |
Jeff Layton | 5c1c669 | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 993 | ctx = locks_get_lock_context(inode, request->fl_type); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 994 | if (!ctx) |
Jeff Layton | 5c1c669 | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 995 | return (request->fl_type == F_UNLCK) ? 0 : -ENOMEM; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 996 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | /* |
| 998 | * We may need two file_lock structures for this operation, |
| 999 | * so we get them in advance to avoid races. |
Miklos Szeredi | 39005d0 | 2006-06-23 02:05:10 -0700 | [diff] [blame] | 1000 | * |
| 1001 | * In some cases we can be sure, that no new locks will be needed |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1002 | */ |
Miklos Szeredi | 39005d0 | 2006-06-23 02:05:10 -0700 | [diff] [blame] | 1003 | if (!(request->fl_flags & FL_ACCESS) && |
| 1004 | (request->fl_type != F_UNLCK || |
| 1005 | request->fl_start != 0 || request->fl_end != OFFSET_MAX)) { |
| 1006 | new_fl = locks_alloc_lock(); |
| 1007 | new_fl2 = locks_alloc_lock(); |
| 1008 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1009 | |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 1010 | percpu_down_read_preempt_disable(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1011 | spin_lock(&ctx->flc_lock); |
Jeff Layton | 1cb3601 | 2013-06-21 08:58:12 -0400 | [diff] [blame] | 1012 | /* |
| 1013 | * New lock request. Walk all POSIX locks and look for conflicts. If |
| 1014 | * there are any, either return error or put the request on the |
Jeff Layton | 48f7418 | 2013-06-21 08:58:18 -0400 | [diff] [blame] | 1015 | * blocker's list of waiters and the global blocked_hash. |
Jeff Layton | 1cb3601 | 2013-06-21 08:58:12 -0400 | [diff] [blame] | 1016 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1017 | if (request->fl_type != F_UNLCK) { |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1018 | list_for_each_entry(fl, &ctx->flc_posix, fl_list) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1019 | if (!posix_locks_conflict(request, fl)) |
| 1020 | continue; |
Andy Adamson | 5842add | 2006-03-26 01:37:26 -0800 | [diff] [blame] | 1021 | if (conflock) |
Kinglong Mee | 3fe0fff1 | 2014-08-22 10:18:42 -0400 | [diff] [blame] | 1022 | locks_copy_conflock(conflock, fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1023 | error = -EAGAIN; |
| 1024 | if (!(request->fl_flags & FL_SLEEP)) |
| 1025 | goto out; |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 1026 | /* |
| 1027 | * Deadlock detection and insertion into the blocked |
| 1028 | * locks list must be done while holding the same lock! |
| 1029 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | error = -EDEADLK; |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 1031 | spin_lock(&blocked_lock_lock); |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 1032 | if (likely(!posix_locks_deadlock(request, fl))) { |
| 1033 | error = FILE_LOCK_DEFERRED; |
| 1034 | __locks_insert_block(fl, request); |
| 1035 | } |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 1036 | spin_unlock(&blocked_lock_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1037 | goto out; |
| 1038 | } |
| 1039 | } |
| 1040 | |
| 1041 | /* If we're just looking for a conflict, we're done. */ |
| 1042 | error = 0; |
| 1043 | if (request->fl_flags & FL_ACCESS) |
| 1044 | goto out; |
| 1045 | |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1046 | /* Find the first old lock with the same owner as the new lock */ |
| 1047 | list_for_each_entry(fl, &ctx->flc_posix, fl_list) { |
| 1048 | if (posix_same_owner(request, fl)) |
| 1049 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1050 | } |
| 1051 | |
Jeff Layton | 1cb3601 | 2013-06-21 08:58:12 -0400 | [diff] [blame] | 1052 | /* Process locks with this owner. */ |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1053 | list_for_each_entry_safe_from(fl, tmp, &ctx->flc_posix, fl_list) { |
| 1054 | if (!posix_same_owner(request, fl)) |
| 1055 | break; |
| 1056 | |
| 1057 | /* Detect adjacent or overlapping regions (if same lock type) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1058 | if (request->fl_type == fl->fl_type) { |
Olaf Kirch | 449231d | 2005-08-25 16:25:35 -0700 | [diff] [blame] | 1059 | /* In all comparisons of start vs end, use |
| 1060 | * "start - 1" rather than "end + 1". If end |
| 1061 | * is OFFSET_MAX, end + 1 will become negative. |
| 1062 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1063 | if (fl->fl_end < request->fl_start - 1) |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1064 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | /* If the next lock in the list has entirely bigger |
| 1066 | * addresses than the new one, insert the lock here. |
| 1067 | */ |
Olaf Kirch | 449231d | 2005-08-25 16:25:35 -0700 | [diff] [blame] | 1068 | if (fl->fl_start - 1 > request->fl_end) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1069 | break; |
| 1070 | |
| 1071 | /* If we come here, the new and old lock are of the |
| 1072 | * same type and adjacent or overlapping. Make one |
| 1073 | * lock yielding from the lower start address of both |
| 1074 | * locks to the higher end address. |
| 1075 | */ |
| 1076 | if (fl->fl_start > request->fl_start) |
| 1077 | fl->fl_start = request->fl_start; |
| 1078 | else |
| 1079 | request->fl_start = fl->fl_start; |
| 1080 | if (fl->fl_end < request->fl_end) |
| 1081 | fl->fl_end = request->fl_end; |
| 1082 | else |
| 1083 | request->fl_end = fl->fl_end; |
| 1084 | if (added) { |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1085 | locks_delete_lock_ctx(fl, &dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1086 | continue; |
| 1087 | } |
| 1088 | request = fl; |
Jeff Layton | b9746ef | 2013-06-21 08:58:13 -0400 | [diff] [blame] | 1089 | added = true; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1090 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1091 | /* Processing for different lock types is a bit |
| 1092 | * more complex. |
| 1093 | */ |
| 1094 | if (fl->fl_end < request->fl_start) |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1095 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1096 | if (fl->fl_start > request->fl_end) |
| 1097 | break; |
| 1098 | if (request->fl_type == F_UNLCK) |
Jeff Layton | b9746ef | 2013-06-21 08:58:13 -0400 | [diff] [blame] | 1099 | added = true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1100 | if (fl->fl_start < request->fl_start) |
| 1101 | left = fl; |
| 1102 | /* If the next lock in the list has a higher end |
| 1103 | * address than the new one, insert the new one here. |
| 1104 | */ |
| 1105 | if (fl->fl_end > request->fl_end) { |
| 1106 | right = fl; |
| 1107 | break; |
| 1108 | } |
| 1109 | if (fl->fl_start >= request->fl_start) { |
| 1110 | /* The new lock completely replaces an old |
| 1111 | * one (This may happen several times). |
| 1112 | */ |
| 1113 | if (added) { |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1114 | locks_delete_lock_ctx(fl, &dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1115 | continue; |
| 1116 | } |
Jeff Layton | b84d49f | 2014-08-12 08:03:49 -0400 | [diff] [blame] | 1117 | /* |
| 1118 | * Replace the old lock with new_fl, and |
| 1119 | * remove the old one. It's safe to do the |
| 1120 | * insert here since we know that we won't be |
| 1121 | * using new_fl later, and that the lock is |
| 1122 | * just replacing an existing lock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | */ |
Jeff Layton | b84d49f | 2014-08-12 08:03:49 -0400 | [diff] [blame] | 1124 | error = -ENOLCK; |
| 1125 | if (!new_fl) |
| 1126 | goto out; |
| 1127 | locks_copy_lock(new_fl, request); |
| 1128 | request = new_fl; |
| 1129 | new_fl = NULL; |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1130 | locks_insert_lock_ctx(request, &fl->fl_list); |
| 1131 | locks_delete_lock_ctx(fl, &dispose); |
Jeff Layton | b9746ef | 2013-06-21 08:58:13 -0400 | [diff] [blame] | 1132 | added = true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1133 | } |
| 1134 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1135 | } |
| 1136 | |
Miklos Szeredi | 0d9a490 | 2006-06-23 02:05:09 -0700 | [diff] [blame] | 1137 | /* |
Jeff Layton | 1cb3601 | 2013-06-21 08:58:12 -0400 | [diff] [blame] | 1138 | * The above code only modifies existing locks in case of merging or |
| 1139 | * replacing. If new lock(s) need to be inserted all modifications are |
| 1140 | * done below this, so it's safe yet to bail out. |
Miklos Szeredi | 0d9a490 | 2006-06-23 02:05:09 -0700 | [diff] [blame] | 1141 | */ |
| 1142 | error = -ENOLCK; /* "no luck" */ |
| 1143 | if (right && left == right && !new_fl2) |
| 1144 | goto out; |
| 1145 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1146 | error = 0; |
| 1147 | if (!added) { |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 1148 | if (request->fl_type == F_UNLCK) { |
| 1149 | if (request->fl_flags & FL_EXISTS) |
| 1150 | error = -ENOENT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1151 | goto out; |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 1152 | } |
Miklos Szeredi | 0d9a490 | 2006-06-23 02:05:09 -0700 | [diff] [blame] | 1153 | |
| 1154 | if (!new_fl) { |
| 1155 | error = -ENOLCK; |
| 1156 | goto out; |
| 1157 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1158 | locks_copy_lock(new_fl, request); |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1159 | locks_insert_lock_ctx(new_fl, &fl->fl_list); |
Jeff Layton | 2e2f756f | 2015-02-17 17:08:23 -0500 | [diff] [blame] | 1160 | fl = new_fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1161 | new_fl = NULL; |
| 1162 | } |
| 1163 | if (right) { |
| 1164 | if (left == right) { |
| 1165 | /* The new lock breaks the old one in two pieces, |
| 1166 | * so we have to use the second new lock. |
| 1167 | */ |
| 1168 | left = new_fl2; |
| 1169 | new_fl2 = NULL; |
| 1170 | locks_copy_lock(left, right); |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1171 | locks_insert_lock_ctx(left, &fl->fl_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1172 | } |
| 1173 | right->fl_start = request->fl_end + 1; |
| 1174 | locks_wake_up_blocks(right); |
| 1175 | } |
| 1176 | if (left) { |
| 1177 | left->fl_end = request->fl_start - 1; |
| 1178 | locks_wake_up_blocks(left); |
| 1179 | } |
| 1180 | out: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1181 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 1182 | percpu_up_read_preempt_enable(&file_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1183 | /* |
| 1184 | * Free any unused locks. |
| 1185 | */ |
| 1186 | if (new_fl) |
| 1187 | locks_free_lock(new_fl); |
| 1188 | if (new_fl2) |
| 1189 | locks_free_lock(new_fl2); |
Jeff Layton | ed9814d | 2014-08-11 14:20:31 -0400 | [diff] [blame] | 1190 | locks_dispose_list(&dispose); |
Jeff Layton | 1890910 | 2016-01-06 21:26:10 -0500 | [diff] [blame] | 1191 | trace_posix_lock_inode(inode, request, error); |
| 1192 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1193 | return error; |
| 1194 | } |
| 1195 | |
| 1196 | /** |
| 1197 | * posix_lock_file - Apply a POSIX-style lock to a file |
| 1198 | * @filp: The file to apply the lock to |
| 1199 | * @fl: The lock to be applied |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 1200 | * @conflock: Place to return a copy of the conflicting lock, if found. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1201 | * |
| 1202 | * Add a POSIX style lock to a file. |
| 1203 | * We merge adjacent & overlapping locks whenever possible. |
| 1204 | * POSIX locks are sorted by owner task, then by starting address |
Trond Myklebust | f475ae9 | 2006-06-29 16:38:32 -0400 | [diff] [blame] | 1205 | * |
| 1206 | * Note that if called with an FL_EXISTS argument, the caller may determine |
| 1207 | * whether or not a lock was successfully freed by testing the return |
| 1208 | * value for -ENOENT. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1209 | */ |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 1210 | int posix_lock_file(struct file *filp, struct file_lock *fl, |
Andy Adamson | 5842add | 2006-03-26 01:37:26 -0800 | [diff] [blame] | 1211 | struct file_lock *conflock) |
| 1212 | { |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 1213 | return posix_lock_inode(locks_inode(filp), fl, conflock); |
Andy Adamson | 5842add | 2006-03-26 01:37:26 -0800 | [diff] [blame] | 1214 | } |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 1215 | EXPORT_SYMBOL(posix_lock_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1216 | |
| 1217 | /** |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1218 | * posix_lock_inode_wait - Apply a POSIX-style lock to a file |
| 1219 | * @inode: inode of file to which lock request should be applied |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1220 | * @fl: The lock to be applied |
| 1221 | * |
Benjamin Coddington | 616fb38 | 2015-10-22 13:38:15 -0400 | [diff] [blame] | 1222 | * Apply a POSIX style lock request to an inode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1223 | */ |
Benjamin Coddington | 616fb38 | 2015-10-22 13:38:15 -0400 | [diff] [blame] | 1224 | static int posix_lock_inode_wait(struct inode *inode, struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1225 | { |
| 1226 | int error; |
| 1227 | might_sleep (); |
| 1228 | for (;;) { |
Jeff Layton | b4d629a | 2016-01-07 18:27:42 -0500 | [diff] [blame] | 1229 | error = posix_lock_inode(inode, fl, NULL); |
Miklos Szeredi | bde74e4 | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 1230 | if (error != FILE_LOCK_DEFERRED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1231 | break; |
| 1232 | error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); |
| 1233 | if (!error) |
| 1234 | continue; |
| 1235 | |
| 1236 | locks_delete_block(fl); |
| 1237 | break; |
| 1238 | } |
| 1239 | return error; |
| 1240 | } |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1241 | |
Jeff Layton | 9e8925b | 2015-11-16 09:49:34 -0500 | [diff] [blame] | 1242 | #ifdef CONFIG_MANDATORY_FILE_LOCKING |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1243 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | * locks_mandatory_locked - Check for an active lock |
Jeff Layton | d7a0698 | 2014-03-10 09:54:15 -0400 | [diff] [blame] | 1245 | * @file: the file to check |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1246 | * |
| 1247 | * Searches the inode's list of locks to find any POSIX locks which conflict. |
| 1248 | * This function is called from locks_verify_locked() only. |
| 1249 | */ |
Jeff Layton | d7a0698 | 2014-03-10 09:54:15 -0400 | [diff] [blame] | 1250 | int locks_mandatory_locked(struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1251 | { |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1252 | int ret; |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 1253 | struct inode *inode = locks_inode(file); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1254 | struct file_lock_context *ctx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1255 | struct file_lock *fl; |
| 1256 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1257 | ctx = smp_load_acquire(&inode->i_flctx); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1258 | if (!ctx || list_empty_careful(&ctx->flc_posix)) |
| 1259 | return 0; |
| 1260 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1261 | /* |
| 1262 | * Search the lock list for this inode for any POSIX locks. |
| 1263 | */ |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1264 | spin_lock(&ctx->flc_lock); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1265 | ret = 0; |
| 1266 | list_for_each_entry(fl, &ctx->flc_posix, fl_list) { |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 1267 | if (fl->fl_owner != current->files && |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1268 | fl->fl_owner != file) { |
| 1269 | ret = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1270 | break; |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1271 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1272 | } |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1273 | spin_unlock(&ctx->flc_lock); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1274 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1275 | } |
| 1276 | |
| 1277 | /** |
| 1278 | * locks_mandatory_area - Check for a conflicting lock |
Christoph Hellwig | acc1557 | 2015-12-03 12:59:49 +0100 | [diff] [blame] | 1279 | * @inode: the file to check |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1280 | * @filp: how the file was opened (if it was) |
Christoph Hellwig | acc1557 | 2015-12-03 12:59:49 +0100 | [diff] [blame] | 1281 | * @start: first byte in the file to check |
| 1282 | * @end: lastbyte in the file to check |
| 1283 | * @type: %F_WRLCK for a write lock, else %F_RDLCK |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1284 | * |
| 1285 | * Searches the inode's list of locks to find any POSIX locks which conflict. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1286 | */ |
Christoph Hellwig | acc1557 | 2015-12-03 12:59:49 +0100 | [diff] [blame] | 1287 | int locks_mandatory_area(struct inode *inode, struct file *filp, loff_t start, |
| 1288 | loff_t end, unsigned char type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1289 | { |
| 1290 | struct file_lock fl; |
| 1291 | int error; |
Jeff Layton | 29723ad | 2014-03-10 09:54:19 -0400 | [diff] [blame] | 1292 | bool sleep = false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1293 | |
| 1294 | locks_init_lock(&fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | fl.fl_pid = current->tgid; |
| 1296 | fl.fl_file = filp; |
| 1297 | fl.fl_flags = FL_POSIX | FL_ACCESS; |
| 1298 | if (filp && !(filp->f_flags & O_NONBLOCK)) |
Jeff Layton | 29723ad | 2014-03-10 09:54:19 -0400 | [diff] [blame] | 1299 | sleep = true; |
Christoph Hellwig | acc1557 | 2015-12-03 12:59:49 +0100 | [diff] [blame] | 1300 | fl.fl_type = type; |
| 1301 | fl.fl_start = start; |
| 1302 | fl.fl_end = end; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | |
| 1304 | for (;;) { |
Jeff Layton | 29723ad | 2014-03-10 09:54:19 -0400 | [diff] [blame] | 1305 | if (filp) { |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 1306 | fl.fl_owner = filp; |
Jeff Layton | 29723ad | 2014-03-10 09:54:19 -0400 | [diff] [blame] | 1307 | fl.fl_flags &= ~FL_SLEEP; |
Jeff Layton | b4d629a | 2016-01-07 18:27:42 -0500 | [diff] [blame] | 1308 | error = posix_lock_inode(inode, &fl, NULL); |
Jeff Layton | 29723ad | 2014-03-10 09:54:19 -0400 | [diff] [blame] | 1309 | if (!error) |
| 1310 | break; |
| 1311 | } |
| 1312 | |
| 1313 | if (sleep) |
| 1314 | fl.fl_flags |= FL_SLEEP; |
| 1315 | fl.fl_owner = current->files; |
Jeff Layton | b4d629a | 2016-01-07 18:27:42 -0500 | [diff] [blame] | 1316 | error = posix_lock_inode(inode, &fl, NULL); |
Miklos Szeredi | bde74e4 | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 1317 | if (error != FILE_LOCK_DEFERRED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1318 | break; |
| 1319 | error = wait_event_interruptible(fl.fl_wait, !fl.fl_next); |
| 1320 | if (!error) { |
| 1321 | /* |
| 1322 | * If we've been sleeping someone might have |
| 1323 | * changed the permissions behind our back. |
| 1324 | */ |
Pavel Emelyanov | a16877c | 2007-10-01 14:41:11 -0700 | [diff] [blame] | 1325 | if (__mandatory_lock(inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1326 | continue; |
| 1327 | } |
| 1328 | |
| 1329 | locks_delete_block(&fl); |
| 1330 | break; |
| 1331 | } |
| 1332 | |
| 1333 | return error; |
| 1334 | } |
| 1335 | |
| 1336 | EXPORT_SYMBOL(locks_mandatory_area); |
Jeff Layton | 9e8925b | 2015-11-16 09:49:34 -0500 | [diff] [blame] | 1337 | #endif /* CONFIG_MANDATORY_FILE_LOCKING */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1338 | |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1339 | static void lease_clear_pending(struct file_lock *fl, int arg) |
| 1340 | { |
| 1341 | switch (arg) { |
| 1342 | case F_UNLCK: |
| 1343 | fl->fl_flags &= ~FL_UNLOCK_PENDING; |
| 1344 | /* fall through: */ |
| 1345 | case F_RDLCK: |
| 1346 | fl->fl_flags &= ~FL_DOWNGRADE_PENDING; |
| 1347 | } |
| 1348 | } |
| 1349 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1350 | /* We already had a lease on this file; just change its type */ |
Jeff Layton | 7448cc3 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1351 | int lease_modify(struct file_lock *fl, int arg, struct list_head *dispose) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1352 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1353 | int error = assign_type(fl, arg); |
| 1354 | |
| 1355 | if (error) |
| 1356 | return error; |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1357 | lease_clear_pending(fl, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1358 | locks_wake_up_blocks(fl); |
Filipe Brandenburger | 3b6e272 | 2012-07-27 00:42:52 -0400 | [diff] [blame] | 1359 | if (arg == F_UNLCK) { |
| 1360 | struct file *filp = fl->fl_file; |
| 1361 | |
| 1362 | f_delown(filp); |
| 1363 | filp->f_owner.signum = 0; |
J. Bruce Fields | 96d6d59 | 2012-07-27 16:18:00 -0400 | [diff] [blame] | 1364 | fasync_helper(0, fl->fl_file, 0, &fl->fl_fasync); |
| 1365 | if (fl->fl_fasync != NULL) { |
| 1366 | printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync); |
| 1367 | fl->fl_fasync = NULL; |
| 1368 | } |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1369 | locks_delete_lock_ctx(fl, dispose); |
Filipe Brandenburger | 3b6e272 | 2012-07-27 00:42:52 -0400 | [diff] [blame] | 1370 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1371 | return 0; |
| 1372 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | EXPORT_SYMBOL(lease_modify); |
| 1374 | |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1375 | static bool past_time(unsigned long then) |
| 1376 | { |
| 1377 | if (!then) |
| 1378 | /* 0 is a special value meaning "this never expires": */ |
| 1379 | return false; |
| 1380 | return time_after(jiffies, then); |
| 1381 | } |
| 1382 | |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1383 | static void time_out_leases(struct inode *inode, struct list_head *dispose) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1384 | { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1385 | struct file_lock_context *ctx = inode->i_flctx; |
| 1386 | struct file_lock *fl, *tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1387 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1388 | lockdep_assert_held(&ctx->flc_lock); |
Jeff Layton | f82b4b6 | 2014-08-22 18:50:48 -0400 | [diff] [blame] | 1389 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1390 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) { |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 1391 | trace_time_out_leases(inode, fl); |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1392 | if (past_time(fl->fl_downgrade_time)) |
Jeff Layton | 7448cc3 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1393 | lease_modify(fl, F_RDLCK, dispose); |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1394 | if (past_time(fl->fl_break_time)) |
Jeff Layton | 7448cc3 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1395 | lease_modify(fl, F_UNLCK, dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | } |
| 1397 | } |
| 1398 | |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1399 | static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker) |
| 1400 | { |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 1401 | if ((breaker->fl_flags & FL_LAYOUT) != (lease->fl_flags & FL_LAYOUT)) |
| 1402 | return false; |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1403 | if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE)) |
| 1404 | return false; |
| 1405 | return locks_conflict(breaker, lease); |
| 1406 | } |
| 1407 | |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1408 | static bool |
| 1409 | any_leases_conflict(struct inode *inode, struct file_lock *breaker) |
| 1410 | { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1411 | struct file_lock_context *ctx = inode->i_flctx; |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1412 | struct file_lock *fl; |
| 1413 | |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1414 | lockdep_assert_held(&ctx->flc_lock); |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1415 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1416 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1417 | if (leases_conflict(fl, breaker)) |
| 1418 | return true; |
| 1419 | } |
| 1420 | return false; |
| 1421 | } |
| 1422 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1423 | /** |
| 1424 | * __break_lease - revoke all outstanding leases on file |
| 1425 | * @inode: the inode of the file to return |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1426 | * @mode: O_RDONLY: break only write leases; O_WRONLY or O_RDWR: |
| 1427 | * break all leases |
| 1428 | * @type: FL_LEASE: break leases and delegations; FL_DELEG: break |
| 1429 | * only delegations |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | * |
david m. richter | 87250dd | 2007-05-09 16:10:27 -0400 | [diff] [blame] | 1431 | * break_lease (inlined for speed) has checked there already is at least |
| 1432 | * some kind of lock (maybe a lease) on this file. Leases are broken on |
| 1433 | * a call to open() or truncate(). This function can sleep unless you |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1434 | * specified %O_NONBLOCK to your open(). |
| 1435 | */ |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1436 | int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1437 | { |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1438 | int error = 0; |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1439 | struct file_lock_context *ctx; |
Yan, Zheng | a901125 | 2015-03-27 10:34:20 +0800 | [diff] [blame] | 1440 | struct file_lock *new_fl, *fl, *tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1441 | unsigned long break_time; |
Al Viro | 8737c93 | 2009-12-24 06:47:55 -0500 | [diff] [blame] | 1442 | int want_write = (mode & O_ACCMODE) != O_RDONLY; |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1443 | LIST_HEAD(dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1444 | |
Al Viro | 8737c93 | 2009-12-24 06:47:55 -0500 | [diff] [blame] | 1445 | new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK); |
Linus Torvalds | 6d4b9e3 | 2011-12-26 10:25:26 -0800 | [diff] [blame] | 1446 | if (IS_ERR(new_fl)) |
| 1447 | return PTR_ERR(new_fl); |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1448 | new_fl->fl_flags = type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1449 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1450 | /* typically we will check that ctx is non-NULL before calling */ |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1451 | ctx = smp_load_acquire(&inode->i_flctx); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1452 | if (!ctx) { |
| 1453 | WARN_ON_ONCE(1); |
| 1454 | return error; |
| 1455 | } |
| 1456 | |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 1457 | percpu_down_read_preempt_disable(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1458 | spin_lock(&ctx->flc_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1459 | |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1460 | time_out_leases(inode, &dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1462 | if (!any_leases_conflict(inode, new_fl)) |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1463 | goto out; |
| 1464 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1465 | break_time = 0; |
| 1466 | if (lease_break_time > 0) { |
| 1467 | break_time = jiffies + lease_break_time * HZ; |
| 1468 | if (break_time == 0) |
| 1469 | break_time++; /* so that 0 means no break time */ |
| 1470 | } |
| 1471 | |
Yan, Zheng | a901125 | 2015-03-27 10:34:20 +0800 | [diff] [blame] | 1472 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) { |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1473 | if (!leases_conflict(fl, new_fl)) |
| 1474 | continue; |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1475 | if (want_write) { |
| 1476 | if (fl->fl_flags & FL_UNLOCK_PENDING) |
| 1477 | continue; |
| 1478 | fl->fl_flags |= FL_UNLOCK_PENDING; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1479 | fl->fl_break_time = break_time; |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1480 | } else { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1481 | if (lease_breaking(fl)) |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1482 | continue; |
| 1483 | fl->fl_flags |= FL_DOWNGRADE_PENDING; |
| 1484 | fl->fl_downgrade_time = break_time; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1485 | } |
Jeff Layton | 4d01b7f | 2014-09-01 15:06:54 -0400 | [diff] [blame] | 1486 | if (fl->fl_lmops->lm_break(fl)) |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1487 | locks_delete_lock_ctx(fl, &dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1488 | } |
| 1489 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1490 | if (list_empty(&ctx->flc_lease)) |
Jeff Layton | 4d01b7f | 2014-09-01 15:06:54 -0400 | [diff] [blame] | 1491 | goto out; |
| 1492 | |
Jeff Layton | 843c6b2 | 2014-09-01 14:27:43 -0400 | [diff] [blame] | 1493 | if (mode & O_NONBLOCK) { |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 1494 | trace_break_lease_noblock(inode, new_fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1495 | error = -EWOULDBLOCK; |
| 1496 | goto out; |
| 1497 | } |
| 1498 | |
| 1499 | restart: |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1500 | fl = list_first_entry(&ctx->flc_lease, struct file_lock, fl_list); |
| 1501 | break_time = fl->fl_break_time; |
Jeff Layton | f1c6bb2 | 2014-04-15 06:17:49 -0400 | [diff] [blame] | 1502 | if (break_time != 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1503 | break_time -= jiffies; |
Jeff Layton | f1c6bb2 | 2014-04-15 06:17:49 -0400 | [diff] [blame] | 1504 | if (break_time == 0) |
| 1505 | break_time++; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1506 | locks_insert_block(fl, new_fl); |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 1507 | trace_break_lease_block(inode, new_fl); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1508 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 1509 | percpu_up_read_preempt_enable(&file_rwsem); |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 1510 | |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1511 | locks_dispose_list(&dispose); |
Matthew Wilcox | 4321e01 | 2008-01-14 21:28:30 -0700 | [diff] [blame] | 1512 | error = wait_event_interruptible_timeout(new_fl->fl_wait, |
| 1513 | !new_fl->fl_next, break_time); |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 1514 | |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 1515 | percpu_down_read_preempt_disable(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1516 | spin_lock(&ctx->flc_lock); |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 1517 | trace_break_lease_unblock(inode, new_fl); |
Jeff Layton | 1c8c601 | 2013-06-21 08:58:15 -0400 | [diff] [blame] | 1518 | locks_delete_block(new_fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1519 | if (error >= 0) { |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1520 | /* |
| 1521 | * Wait for the next conflicting lease that has not been |
| 1522 | * broken yet |
| 1523 | */ |
Jeff Layton | 03d12dd | 2014-09-01 14:53:41 -0400 | [diff] [blame] | 1524 | if (error == 0) |
| 1525 | time_out_leases(inode, &dispose); |
| 1526 | if (any_leases_conflict(inode, new_fl)) |
| 1527 | goto restart; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1528 | error = 0; |
| 1529 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1530 | out: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1531 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 1532 | percpu_up_read_preempt_enable(&file_rwsem); |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1533 | locks_dispose_list(&dispose); |
Linus Torvalds | 6d4b9e3 | 2011-12-26 10:25:26 -0800 | [diff] [blame] | 1534 | locks_free_lock(new_fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1535 | return error; |
| 1536 | } |
| 1537 | |
| 1538 | EXPORT_SYMBOL(__break_lease); |
| 1539 | |
| 1540 | /** |
Randy Dunlap | a6b9191 | 2008-03-19 17:01:00 -0700 | [diff] [blame] | 1541 | * lease_get_mtime - get the last modified time of an inode |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1542 | * @inode: the inode |
| 1543 | * @time: pointer to a timespec which will contain the last modified time |
| 1544 | * |
| 1545 | * This is to force NFS clients to flush their caches for files with |
| 1546 | * exclusive leases. The justification is that if someone has an |
Randy Dunlap | a6b9191 | 2008-03-19 17:01:00 -0700 | [diff] [blame] | 1547 | * exclusive lease, then they could be modifying it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1548 | */ |
| 1549 | void lease_get_mtime(struct inode *inode, struct timespec *time) |
| 1550 | { |
Jeff Layton | bfe8602 | 2014-08-22 10:18:44 -0400 | [diff] [blame] | 1551 | bool has_lease = false; |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1552 | struct file_lock_context *ctx; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1553 | struct file_lock *fl; |
Jeff Layton | bfe8602 | 2014-08-22 10:18:44 -0400 | [diff] [blame] | 1554 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1555 | ctx = smp_load_acquire(&inode->i_flctx); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1556 | if (ctx && !list_empty_careful(&ctx->flc_lease)) { |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1557 | spin_lock(&ctx->flc_lock); |
Geliang Tang | 8ace5df | 2015-11-18 21:40:33 +0800 | [diff] [blame] | 1558 | fl = list_first_entry_or_null(&ctx->flc_lease, |
| 1559 | struct file_lock, fl_list); |
| 1560 | if (fl && (fl->fl_type == F_WRLCK)) |
| 1561 | has_lease = true; |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1562 | spin_unlock(&ctx->flc_lock); |
Jeff Layton | bfe8602 | 2014-08-22 10:18:44 -0400 | [diff] [blame] | 1563 | } |
| 1564 | |
| 1565 | if (has_lease) |
Deepa Dinamani | c2050a4 | 2016-09-14 07:48:06 -0700 | [diff] [blame] | 1566 | *time = current_time(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1567 | else |
| 1568 | *time = inode->i_mtime; |
| 1569 | } |
| 1570 | |
| 1571 | EXPORT_SYMBOL(lease_get_mtime); |
| 1572 | |
| 1573 | /** |
| 1574 | * fcntl_getlease - Enquire what lease is currently active |
| 1575 | * @filp: the file |
| 1576 | * |
| 1577 | * The value returned by this function will be one of |
| 1578 | * (if no lease break is pending): |
| 1579 | * |
| 1580 | * %F_RDLCK to indicate a shared lease is held. |
| 1581 | * |
| 1582 | * %F_WRLCK to indicate an exclusive lease is held. |
| 1583 | * |
| 1584 | * %F_UNLCK to indicate no lease is held. |
| 1585 | * |
| 1586 | * (if a lease break is pending): |
| 1587 | * |
| 1588 | * %F_RDLCK to indicate an exclusive lease needs to be |
| 1589 | * changed to a shared lease (or removed). |
| 1590 | * |
| 1591 | * %F_UNLCK to indicate the lease needs to be removed. |
| 1592 | * |
| 1593 | * XXX: sfr & willy disagree over whether F_INPROGRESS |
| 1594 | * should be returned to userspace. |
| 1595 | */ |
| 1596 | int fcntl_getlease(struct file *filp) |
| 1597 | { |
| 1598 | struct file_lock *fl; |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 1599 | struct inode *inode = locks_inode(filp); |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1600 | struct file_lock_context *ctx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1601 | int type = F_UNLCK; |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1602 | LIST_HEAD(dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1603 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1604 | ctx = smp_load_acquire(&inode->i_flctx); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1605 | if (ctx && !list_empty_careful(&ctx->flc_lease)) { |
Peter Zijlstra | 5f43086 | 2016-10-08 10:12:28 +0200 | [diff] [blame] | 1606 | percpu_down_read_preempt_disable(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1607 | spin_lock(&ctx->flc_lock); |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 1608 | time_out_leases(inode, &dispose); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1609 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
| 1610 | if (fl->fl_file != filp) |
| 1611 | continue; |
J. Bruce Fields | 778fc54 | 2011-07-26 18:25:49 -0400 | [diff] [blame] | 1612 | type = target_leasetype(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1613 | break; |
| 1614 | } |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1615 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 5f43086 | 2016-10-08 10:12:28 +0200 | [diff] [blame] | 1616 | percpu_up_read_preempt_enable(&file_rwsem); |
| 1617 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1618 | locks_dispose_list(&dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1619 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1620 | return type; |
| 1621 | } |
| 1622 | |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1623 | /** |
| 1624 | * check_conflicting_open - see if the given dentry points to a file that has |
| 1625 | * an existing open that would conflict with the |
| 1626 | * desired lease. |
| 1627 | * @dentry: dentry to check |
| 1628 | * @arg: type of lease that we're trying to acquire |
Randy Dunlap | 7fadc59 | 2015-08-09 18:43:17 -0700 | [diff] [blame] | 1629 | * @flags: current lock flags |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1630 | * |
| 1631 | * Check to see if there's an existing open fd on this file that would |
| 1632 | * conflict with the lease we're trying to set. |
| 1633 | */ |
| 1634 | static int |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 1635 | check_conflicting_open(const struct dentry *dentry, const long arg, int flags) |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1636 | { |
| 1637 | int ret = 0; |
| 1638 | struct inode *inode = dentry->d_inode; |
| 1639 | |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 1640 | if (flags & FL_LAYOUT) |
| 1641 | return 0; |
| 1642 | |
Miklos Szeredi | 4d0c5ba | 2016-09-16 12:44:21 +0200 | [diff] [blame] | 1643 | if ((arg == F_RDLCK) && |
| 1644 | (atomic_read(&d_real_inode(dentry)->i_writecount) > 0)) |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1645 | return -EAGAIN; |
| 1646 | |
| 1647 | if ((arg == F_WRLCK) && ((d_count(dentry) > 1) || |
| 1648 | (atomic_read(&inode->i_count) > 1))) |
| 1649 | ret = -EAGAIN; |
| 1650 | |
| 1651 | return ret; |
| 1652 | } |
| 1653 | |
Jeff Layton | e6f5c78 | 2014-08-22 10:40:25 -0400 | [diff] [blame] | 1654 | static int |
| 1655 | generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1656 | { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1657 | struct file_lock *fl, *my_fl = NULL, *lease; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 1658 | struct dentry *dentry = filp->f_path.dentry; |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 1659 | struct inode *inode = dentry->d_inode; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1660 | struct file_lock_context *ctx; |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1661 | bool is_deleg = (*flp)->fl_flags & FL_DELEG; |
J. Bruce Fields | c1f24ef | 2011-08-19 10:59:49 -0400 | [diff] [blame] | 1662 | int error; |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1663 | LIST_HEAD(dispose); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1664 | |
J. Bruce Fields | 096657b | 2010-10-30 17:31:14 -0400 | [diff] [blame] | 1665 | lease = *flp; |
Jeff Layton | 62af4f1 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 1666 | trace_generic_add_lease(inode, lease); |
| 1667 | |
Jeff Layton | 5c1c669 | 2015-04-03 09:04:03 -0400 | [diff] [blame] | 1668 | /* Note that arg is never F_UNLCK here */ |
| 1669 | ctx = locks_get_lock_context(inode, arg); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1670 | if (!ctx) |
| 1671 | return -ENOMEM; |
| 1672 | |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1673 | /* |
| 1674 | * In the delegation case we need mutual exclusion with |
| 1675 | * a number of operations that take the i_mutex. We trylock |
| 1676 | * because delegations are an optional optimization, and if |
| 1677 | * there's some chance of a conflict--we'd rather not |
| 1678 | * bother, maybe that's a sign this just isn't a good file to |
| 1679 | * hand out a delegation on. |
| 1680 | */ |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 1681 | if (is_deleg && !inode_trylock(inode)) |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1682 | return -EAGAIN; |
| 1683 | |
| 1684 | if (is_deleg && arg == F_WRLCK) { |
| 1685 | /* Write delegations are not currently supported: */ |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 1686 | inode_unlock(inode); |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1687 | WARN_ON_ONCE(1); |
| 1688 | return -EINVAL; |
| 1689 | } |
J. Bruce Fields | 096657b | 2010-10-30 17:31:14 -0400 | [diff] [blame] | 1690 | |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 1691 | percpu_down_read_preempt_disable(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1692 | spin_lock(&ctx->flc_lock); |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1693 | time_out_leases(inode, &dispose); |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 1694 | error = check_conflicting_open(dentry, arg, lease->fl_flags); |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1695 | if (error) |
J. Bruce Fields | 096657b | 2010-10-30 17:31:14 -0400 | [diff] [blame] | 1696 | goto out; |
Pavel Emelyanov | 85c5958 | 2007-09-20 12:45:02 +0400 | [diff] [blame] | 1697 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1698 | /* |
| 1699 | * At this point, we know that if there is an exclusive |
| 1700 | * lease on this file, then we hold it on this filp |
| 1701 | * (otherwise our open of this file would have blocked). |
| 1702 | * And if we are trying to acquire an exclusive lease, |
| 1703 | * then the file is not open by anyone (including us) |
| 1704 | * except for this filp. |
| 1705 | */ |
J. Bruce Fields | c1f24ef | 2011-08-19 10:59:49 -0400 | [diff] [blame] | 1706 | error = -EAGAIN; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1707 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
Christoph Hellwig | 2ab99ee | 2015-01-21 19:14:02 +0100 | [diff] [blame] | 1708 | if (fl->fl_file == filp && |
| 1709 | fl->fl_owner == lease->fl_owner) { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1710 | my_fl = fl; |
J. Bruce Fields | c1f24ef | 2011-08-19 10:59:49 -0400 | [diff] [blame] | 1711 | continue; |
| 1712 | } |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1713 | |
J. Bruce Fields | c1f24ef | 2011-08-19 10:59:49 -0400 | [diff] [blame] | 1714 | /* |
| 1715 | * No exclusive leases if someone else has a lease on |
| 1716 | * this file: |
| 1717 | */ |
| 1718 | if (arg == F_WRLCK) |
| 1719 | goto out; |
| 1720 | /* |
| 1721 | * Modifying our existing lease is OK, but no getting a |
| 1722 | * new lease if someone else is opening for write: |
| 1723 | */ |
| 1724 | if (fl->fl_flags & FL_UNLOCK_PENDING) |
| 1725 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1726 | } |
| 1727 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1728 | if (my_fl != NULL) { |
Jeff Layton | 0164bf0 | 2015-03-04 17:34:32 -0500 | [diff] [blame] | 1729 | lease = my_fl; |
| 1730 | error = lease->fl_lmops->lm_change(lease, arg, &dispose); |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1731 | if (error) |
| 1732 | goto out; |
| 1733 | goto out_setup; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1734 | } |
| 1735 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1736 | error = -EINVAL; |
| 1737 | if (!leases_enable) |
| 1738 | goto out; |
| 1739 | |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1740 | locks_insert_lock_ctx(lease, &ctx->flc_lease); |
Jeff Layton | 24cbe78 | 2014-02-03 12:13:06 -0500 | [diff] [blame] | 1741 | /* |
| 1742 | * The check in break_lease() is lockless. It's possible for another |
| 1743 | * open to race in after we did the earlier check for a conflicting |
| 1744 | * open but before the lease was inserted. Check again for a |
| 1745 | * conflicting open and cancel the lease if there is one. |
| 1746 | * |
| 1747 | * We also add a barrier here to ensure that the insertion of the lock |
| 1748 | * precedes these checks. |
| 1749 | */ |
| 1750 | smp_mb(); |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 1751 | error = check_conflicting_open(dentry, arg, lease->fl_flags); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1752 | if (error) { |
Jeff Layton | e084c1b | 2015-02-16 14:32:03 -0500 | [diff] [blame] | 1753 | locks_unlink_lock_ctx(lease); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1754 | goto out; |
| 1755 | } |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1756 | |
| 1757 | out_setup: |
| 1758 | if (lease->fl_lmops->lm_setup) |
| 1759 | lease->fl_lmops->lm_setup(lease, priv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1760 | out: |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1761 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 1762 | percpu_up_read_preempt_enable(&file_rwsem); |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1763 | locks_dispose_list(&dispose); |
J. Bruce Fields | df4e8d2 | 2012-03-05 13:18:59 -0500 | [diff] [blame] | 1764 | if (is_deleg) |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 1765 | inode_unlock(inode); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1766 | if (!error && !my_fl) |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1767 | *flp = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1768 | return error; |
| 1769 | } |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1770 | |
Christoph Hellwig | 2ab99ee | 2015-01-21 19:14:02 +0100 | [diff] [blame] | 1771 | static int generic_delete_lease(struct file *filp, void *owner) |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1772 | { |
Jeff Layton | 0efaa7e | 2014-08-22 10:18:45 -0400 | [diff] [blame] | 1773 | int error = -EAGAIN; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1774 | struct file_lock *fl, *victim = NULL; |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 1775 | struct inode *inode = locks_inode(filp); |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1776 | struct file_lock_context *ctx; |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1777 | LIST_HEAD(dispose); |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1778 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 1779 | ctx = smp_load_acquire(&inode->i_flctx); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1780 | if (!ctx) { |
| 1781 | trace_generic_delete_lease(inode, NULL); |
| 1782 | return error; |
| 1783 | } |
| 1784 | |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 1785 | percpu_down_read_preempt_disable(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1786 | spin_lock(&ctx->flc_lock); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1787 | list_for_each_entry(fl, &ctx->flc_lease, fl_list) { |
Christoph Hellwig | 2ab99ee | 2015-01-21 19:14:02 +0100 | [diff] [blame] | 1788 | if (fl->fl_file == filp && |
| 1789 | fl->fl_owner == owner) { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1790 | victim = fl; |
Jeff Layton | 0efaa7e | 2014-08-22 10:18:45 -0400 | [diff] [blame] | 1791 | break; |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1792 | } |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1793 | } |
Jeff Layton | a9b1b45 | 2015-03-14 09:45:35 -0400 | [diff] [blame] | 1794 | trace_generic_delete_lease(inode, victim); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 1795 | if (victim) |
Jeff Layton | 7448cc3 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1796 | error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 1797 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 87709e2 | 2016-05-30 16:48:35 +0200 | [diff] [blame] | 1798 | percpu_up_read_preempt_enable(&file_rwsem); |
Jeff Layton | c45198e | 2014-09-01 07:12:07 -0400 | [diff] [blame] | 1799 | locks_dispose_list(&dispose); |
Jeff Layton | 0efaa7e | 2014-08-22 10:18:45 -0400 | [diff] [blame] | 1800 | return error; |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1801 | } |
| 1802 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1803 | /** |
| 1804 | * generic_setlease - sets a lease on an open file |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1805 | * @filp: file pointer |
| 1806 | * @arg: type of lease to obtain |
| 1807 | * @flp: input - file_lock to use, output - file_lock inserted |
| 1808 | * @priv: private data for lm_setup (may be NULL if lm_setup |
| 1809 | * doesn't require it) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1810 | * |
| 1811 | * The (input) flp->fl_lmops->lm_break function is required |
| 1812 | * by break_lease(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1813 | */ |
Jeff Layton | e6f5c78 | 2014-08-22 10:40:25 -0400 | [diff] [blame] | 1814 | int generic_setlease(struct file *filp, long arg, struct file_lock **flp, |
| 1815 | void **priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1816 | { |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 1817 | struct inode *inode = locks_inode(filp); |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1818 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1819 | |
Eric W. Biederman | 8e96e3b | 2012-03-03 21:17:15 -0800 | [diff] [blame] | 1820 | if ((!uid_eq(current_fsuid(), inode->i_uid)) && !capable(CAP_LEASE)) |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1821 | return -EACCES; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1822 | if (!S_ISREG(inode->i_mode)) |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1823 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1824 | error = security_file_lock(filp, arg); |
| 1825 | if (error) |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1826 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1827 | |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1828 | switch (arg) { |
| 1829 | case F_UNLCK: |
Christoph Hellwig | 2ab99ee | 2015-01-21 19:14:02 +0100 | [diff] [blame] | 1830 | return generic_delete_lease(filp, *priv); |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1831 | case F_RDLCK: |
| 1832 | case F_WRLCK: |
Jeff Layton | 0efaa7e | 2014-08-22 10:18:45 -0400 | [diff] [blame] | 1833 | if (!(*flp)->fl_lmops->lm_break) { |
| 1834 | WARN_ON_ONCE(1); |
| 1835 | return -ENOLCK; |
| 1836 | } |
Christoph Hellwig | 11afe9f | 2015-01-21 19:17:03 +0100 | [diff] [blame] | 1837 | |
Jeff Layton | e6f5c78 | 2014-08-22 10:40:25 -0400 | [diff] [blame] | 1838 | return generic_add_lease(filp, arg, flp, priv); |
J. Bruce Fields | 8335ebd | 2011-09-21 08:34:32 -0400 | [diff] [blame] | 1839 | default: |
Dave Jones | 8d657eb | 2012-07-13 13:35:36 -0400 | [diff] [blame] | 1840 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1841 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1842 | } |
Christoph Hellwig | 0af1a45 | 2007-07-31 00:39:22 -0700 | [diff] [blame] | 1843 | EXPORT_SYMBOL(generic_setlease); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1844 | |
Arnd Bergmann | b89f432 | 2010-09-18 15:09:31 +0200 | [diff] [blame] | 1845 | /** |
Jeff Layton | e51673a | 2014-08-22 18:13:28 -0400 | [diff] [blame] | 1846 | * vfs_setlease - sets a lease on an open file |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1847 | * @filp: file pointer |
| 1848 | * @arg: type of lease to obtain |
| 1849 | * @lease: file_lock to use when adding a lease |
| 1850 | * @priv: private info for lm_setup when adding a lease (may be |
| 1851 | * NULL if lm_setup doesn't require it) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1852 | * |
Jeff Layton | e51673a | 2014-08-22 18:13:28 -0400 | [diff] [blame] | 1853 | * Call this to establish a lease on the file. The "lease" argument is not |
| 1854 | * used for F_UNLCK requests and may be NULL. For commands that set or alter |
Mauro Carvalho Chehab | 80b79dd | 2017-05-27 06:07:18 -0400 | [diff] [blame] | 1855 | * an existing lease, the ``(*lease)->fl_lmops->lm_break`` operation must be |
| 1856 | * set; if not, this function will return -ENOLCK (and generate a scary-looking |
Jeff Layton | e51673a | 2014-08-22 18:13:28 -0400 | [diff] [blame] | 1857 | * stack trace). |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1858 | * |
| 1859 | * The "priv" pointer is passed directly to the lm_setup function as-is. It |
| 1860 | * may be NULL if the lm_setup operation doesn't require it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1861 | */ |
Jeff Layton | e6f5c78 | 2014-08-22 10:40:25 -0400 | [diff] [blame] | 1862 | int |
| 1863 | vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1864 | { |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 1865 | if (filp->f_op->setlease && is_remote_lock(filp)) |
Jeff Layton | f82b4b6 | 2014-08-22 18:50:48 -0400 | [diff] [blame] | 1866 | return filp->f_op->setlease(filp, arg, lease, priv); |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1867 | else |
Jeff Layton | f82b4b6 | 2014-08-22 18:50:48 -0400 | [diff] [blame] | 1868 | return generic_setlease(filp, arg, lease, priv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1869 | } |
J. Bruce Fields | a9933ce | 2007-06-07 17:09:49 -0400 | [diff] [blame] | 1870 | EXPORT_SYMBOL_GPL(vfs_setlease); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1871 | |
J. Bruce Fields | 0ceaf6c | 2010-10-30 17:31:13 -0400 | [diff] [blame] | 1872 | static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1873 | { |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1874 | struct file_lock *fl; |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 1875 | struct fasync_struct *new; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1876 | int error; |
| 1877 | |
Arnd Bergmann | c5b1f0d | 2010-10-27 15:46:08 +0200 | [diff] [blame] | 1878 | fl = lease_alloc(filp, arg); |
| 1879 | if (IS_ERR(fl)) |
| 1880 | return PTR_ERR(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1881 | |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 1882 | new = fasync_alloc(); |
| 1883 | if (!new) { |
| 1884 | locks_free_lock(fl); |
| 1885 | return -ENOMEM; |
| 1886 | } |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1887 | new->fa_fd = fd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1888 | |
Jeff Layton | 1c7dd2f | 2014-08-22 10:55:47 -0400 | [diff] [blame] | 1889 | error = vfs_setlease(filp, arg, &fl, (void **)&new); |
Jeff Layton | 2dfb928 | 2014-08-11 18:14:12 -0400 | [diff] [blame] | 1890 | if (fl) |
| 1891 | locks_free_lock(fl); |
Linus Torvalds | f7347ce | 2010-10-27 12:38:12 -0400 | [diff] [blame] | 1892 | if (new) |
| 1893 | fasync_free(new); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1894 | return error; |
| 1895 | } |
| 1896 | |
| 1897 | /** |
J. Bruce Fields | 0ceaf6c | 2010-10-30 17:31:13 -0400 | [diff] [blame] | 1898 | * fcntl_setlease - sets a lease on an open file |
| 1899 | * @fd: open file descriptor |
| 1900 | * @filp: file pointer |
| 1901 | * @arg: type of lease to obtain |
| 1902 | * |
| 1903 | * Call this fcntl to establish a lease on the file. |
| 1904 | * Note that you also need to call %F_SETSIG to |
| 1905 | * receive a signal when the lease is broken. |
| 1906 | */ |
| 1907 | int fcntl_setlease(unsigned int fd, struct file *filp, long arg) |
| 1908 | { |
| 1909 | if (arg == F_UNLCK) |
Christoph Hellwig | 2ab99ee | 2015-01-21 19:14:02 +0100 | [diff] [blame] | 1910 | return vfs_setlease(filp, F_UNLCK, NULL, (void **)&filp); |
J. Bruce Fields | 0ceaf6c | 2010-10-30 17:31:13 -0400 | [diff] [blame] | 1911 | return do_fcntl_add_lease(fd, filp, arg); |
| 1912 | } |
| 1913 | |
| 1914 | /** |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1915 | * flock_lock_inode_wait - Apply a FLOCK-style lock to a file |
| 1916 | * @inode: inode of the file to apply to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1917 | * @fl: The lock to be applied |
| 1918 | * |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1919 | * Apply a FLOCK style lock request to an inode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1920 | */ |
Benjamin Coddington | 616fb38 | 2015-10-22 13:38:15 -0400 | [diff] [blame] | 1921 | static int flock_lock_inode_wait(struct inode *inode, struct file_lock *fl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1922 | { |
| 1923 | int error; |
| 1924 | might_sleep(); |
| 1925 | for (;;) { |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1926 | error = flock_lock_inode(inode, fl); |
Miklos Szeredi | bde74e4 | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 1927 | if (error != FILE_LOCK_DEFERRED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1928 | break; |
| 1929 | error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); |
| 1930 | if (!error) |
| 1931 | continue; |
| 1932 | |
| 1933 | locks_delete_block(fl); |
| 1934 | break; |
| 1935 | } |
| 1936 | return error; |
| 1937 | } |
| 1938 | |
Jeff Layton | 29d01b2 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 1939 | /** |
Benjamin Coddington | e55c34a | 2015-10-22 13:38:13 -0400 | [diff] [blame] | 1940 | * locks_lock_inode_wait - Apply a lock to an inode |
| 1941 | * @inode: inode of the file to apply to |
| 1942 | * @fl: The lock to be applied |
| 1943 | * |
| 1944 | * Apply a POSIX or FLOCK style lock request to an inode. |
| 1945 | */ |
| 1946 | int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl) |
| 1947 | { |
| 1948 | int res = 0; |
| 1949 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { |
| 1950 | case FL_POSIX: |
| 1951 | res = posix_lock_inode_wait(inode, fl); |
| 1952 | break; |
| 1953 | case FL_FLOCK: |
| 1954 | res = flock_lock_inode_wait(inode, fl); |
| 1955 | break; |
| 1956 | default: |
| 1957 | BUG(); |
| 1958 | } |
| 1959 | return res; |
| 1960 | } |
| 1961 | EXPORT_SYMBOL(locks_lock_inode_wait); |
| 1962 | |
| 1963 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1964 | * sys_flock: - flock() system call. |
| 1965 | * @fd: the file descriptor to lock. |
| 1966 | * @cmd: the type of lock to apply. |
| 1967 | * |
| 1968 | * Apply a %FL_FLOCK style lock to an open file descriptor. |
Mauro Carvalho Chehab | 80b79dd | 2017-05-27 06:07:18 -0400 | [diff] [blame] | 1969 | * The @cmd can be one of: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1970 | * |
Mauro Carvalho Chehab | 80b79dd | 2017-05-27 06:07:18 -0400 | [diff] [blame] | 1971 | * - %LOCK_SH -- a shared lock. |
| 1972 | * - %LOCK_EX -- an exclusive lock. |
| 1973 | * - %LOCK_UN -- remove an existing lock. |
| 1974 | * - %LOCK_MAND -- a 'mandatory' flock. |
| 1975 | * This exists to emulate Windows Share Modes. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1976 | * |
| 1977 | * %LOCK_MAND can be combined with %LOCK_READ or %LOCK_WRITE to allow other |
| 1978 | * processes read and write access respectively. |
| 1979 | */ |
Heiko Carstens | 002c897 | 2009-01-14 14:14:18 +0100 | [diff] [blame] | 1980 | SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1981 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1982 | struct fd f = fdget(fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1983 | struct file_lock *lock; |
| 1984 | int can_sleep, unlock; |
| 1985 | int error; |
| 1986 | |
| 1987 | error = -EBADF; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1988 | if (!f.file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1989 | goto out; |
| 1990 | |
| 1991 | can_sleep = !(cmd & LOCK_NB); |
| 1992 | cmd &= ~LOCK_NB; |
| 1993 | unlock = (cmd == LOCK_UN); |
| 1994 | |
Al Viro | aeb5d72 | 2008-09-02 15:28:45 -0400 | [diff] [blame] | 1995 | if (!unlock && !(cmd & LOCK_MAND) && |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1996 | !(f.file->f_mode & (FMODE_READ|FMODE_WRITE))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1997 | goto out_putf; |
| 1998 | |
Jeff Layton | 6e129d00 | 2014-09-04 10:25:06 -0400 | [diff] [blame] | 1999 | lock = flock_make_lock(f.file, cmd); |
| 2000 | if (IS_ERR(lock)) { |
| 2001 | error = PTR_ERR(lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2002 | goto out_putf; |
Jeff Layton | 6e129d00 | 2014-09-04 10:25:06 -0400 | [diff] [blame] | 2003 | } |
| 2004 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2005 | if (can_sleep) |
| 2006 | lock->fl_flags |= FL_SLEEP; |
| 2007 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 2008 | error = security_file_lock(f.file, lock->fl_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2009 | if (error) |
| 2010 | goto out_free; |
| 2011 | |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2012 | if (f.file->f_op->flock && is_remote_lock(f.file)) |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 2013 | error = f.file->f_op->flock(f.file, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2014 | (can_sleep) ? F_SETLKW : F_SETLK, |
| 2015 | lock); |
| 2016 | else |
Benjamin Coddington | 4f65636 | 2015-10-22 13:38:14 -0400 | [diff] [blame] | 2017 | error = locks_lock_file_wait(f.file, lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2018 | |
| 2019 | out_free: |
Trond Myklebust | 993dfa8 | 2006-03-31 02:30:55 -0800 | [diff] [blame] | 2020 | locks_free_lock(lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2021 | |
| 2022 | out_putf: |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 2023 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2024 | out: |
| 2025 | return error; |
| 2026 | } |
| 2027 | |
J. Bruce Fields | 3ee17ab | 2007-02-21 00:58:50 -0500 | [diff] [blame] | 2028 | /** |
| 2029 | * vfs_test_lock - test file byte range lock |
| 2030 | * @filp: The file to test lock for |
J. Bruce Fields | 6924c55 | 2007-05-11 16:22:50 -0400 | [diff] [blame] | 2031 | * @fl: The lock to test; also used to hold result |
J. Bruce Fields | 3ee17ab | 2007-02-21 00:58:50 -0500 | [diff] [blame] | 2032 | * |
| 2033 | * Returns -ERRNO on failure. Indicates presence of conflicting lock by |
| 2034 | * setting conf->fl_type to something other than F_UNLCK. |
| 2035 | */ |
| 2036 | int vfs_test_lock(struct file *filp, struct file_lock *fl) |
| 2037 | { |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2038 | if (filp->f_op->lock && is_remote_lock(filp)) |
J. Bruce Fields | 3ee17ab | 2007-02-21 00:58:50 -0500 | [diff] [blame] | 2039 | return filp->f_op->lock(filp, F_GETLK, fl); |
| 2040 | posix_test_lock(filp, fl); |
| 2041 | return 0; |
| 2042 | } |
| 2043 | EXPORT_SYMBOL_GPL(vfs_test_lock); |
| 2044 | |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame^] | 2045 | /** |
| 2046 | * locks_translate_pid - translate a file_lock's fl_pid number into a namespace |
| 2047 | * @fl: The file_lock who's fl_pid should be translated |
| 2048 | * @ns: The namespace into which the pid should be translated |
| 2049 | * |
| 2050 | * Used to tranlate a fl_pid into a namespace virtual pid number |
| 2051 | */ |
| 2052 | static pid_t locks_translate_pid(struct file_lock *fl, struct pid_namespace *ns) |
| 2053 | { |
| 2054 | pid_t vnr; |
| 2055 | struct pid *pid; |
| 2056 | |
| 2057 | if (IS_OFDLCK(fl)) |
| 2058 | return -1; |
| 2059 | if (IS_REMOTELCK(fl)) |
| 2060 | return fl->fl_pid; |
| 2061 | |
| 2062 | rcu_read_lock(); |
| 2063 | pid = find_pid_ns(fl->fl_pid, &init_pid_ns); |
| 2064 | vnr = pid_nr_ns(pid, ns); |
| 2065 | rcu_read_unlock(); |
| 2066 | return vnr; |
| 2067 | } |
| 2068 | |
J. Bruce Fields | c2fa1b8 | 2007-02-20 16:10:11 -0500 | [diff] [blame] | 2069 | static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) |
| 2070 | { |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame^] | 2071 | flock->l_pid = locks_translate_pid(fl, task_active_pid_ns(current)); |
J. Bruce Fields | c2fa1b8 | 2007-02-20 16:10:11 -0500 | [diff] [blame] | 2072 | #if BITS_PER_LONG == 32 |
| 2073 | /* |
| 2074 | * Make sure we can represent the posix lock via |
| 2075 | * legacy 32bit flock. |
| 2076 | */ |
| 2077 | if (fl->fl_start > OFFT_OFFSET_MAX) |
| 2078 | return -EOVERFLOW; |
| 2079 | if (fl->fl_end != OFFSET_MAX && fl->fl_end > OFFT_OFFSET_MAX) |
| 2080 | return -EOVERFLOW; |
| 2081 | #endif |
| 2082 | flock->l_start = fl->fl_start; |
| 2083 | flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : |
| 2084 | fl->fl_end - fl->fl_start + 1; |
| 2085 | flock->l_whence = 0; |
J. Bruce Fields | 129a84d | 2007-05-10 18:38:43 -0400 | [diff] [blame] | 2086 | flock->l_type = fl->fl_type; |
J. Bruce Fields | c2fa1b8 | 2007-02-20 16:10:11 -0500 | [diff] [blame] | 2087 | return 0; |
| 2088 | } |
| 2089 | |
| 2090 | #if BITS_PER_LONG == 32 |
| 2091 | static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) |
| 2092 | { |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame^] | 2093 | flock->l_pid = locks_translate_pid(fl, task_active_pid_ns(current)); |
J. Bruce Fields | c2fa1b8 | 2007-02-20 16:10:11 -0500 | [diff] [blame] | 2094 | flock->l_start = fl->fl_start; |
| 2095 | flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : |
| 2096 | fl->fl_end - fl->fl_start + 1; |
| 2097 | flock->l_whence = 0; |
| 2098 | flock->l_type = fl->fl_type; |
| 2099 | } |
| 2100 | #endif |
| 2101 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2102 | /* Report the first existing lock that would conflict with l. |
| 2103 | * This implements the F_GETLK command of fcntl(). |
| 2104 | */ |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2105 | int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2106 | { |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2107 | struct file_lock *fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2108 | int error; |
| 2109 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2110 | fl = locks_alloc_lock(); |
| 2111 | if (fl == NULL) |
| 2112 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2113 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2114 | if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2115 | goto out; |
| 2116 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2117 | error = flock_to_posix_lock(filp, fl, flock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2118 | if (error) |
| 2119 | goto out; |
| 2120 | |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2121 | if (cmd == F_OFD_GETLK) { |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2122 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2123 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2124 | goto out; |
| 2125 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2126 | cmd = F_GETLK; |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2127 | fl->fl_flags |= FL_OFDLCK; |
| 2128 | fl->fl_owner = filp; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2129 | } |
| 2130 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2131 | error = vfs_test_lock(filp, fl); |
J. Bruce Fields | 3ee17ab | 2007-02-21 00:58:50 -0500 | [diff] [blame] | 2132 | if (error) |
| 2133 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2134 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2135 | flock->l_type = fl->fl_type; |
| 2136 | if (fl->fl_type != F_UNLCK) { |
| 2137 | error = posix_lock_to_flock(flock, fl); |
J. Bruce Fields | c2fa1b8 | 2007-02-20 16:10:11 -0500 | [diff] [blame] | 2138 | if (error) |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2139 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2140 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2141 | out: |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2142 | locks_free_lock(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2143 | return error; |
| 2144 | } |
| 2145 | |
Marc Eshel | 7723ec9 | 2007-01-18 15:08:55 -0500 | [diff] [blame] | 2146 | /** |
| 2147 | * vfs_lock_file - file byte range lock |
| 2148 | * @filp: The file to apply the lock to |
| 2149 | * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.) |
| 2150 | * @fl: The lock to be applied |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 2151 | * @conf: Place to return a copy of the conflicting lock, if found. |
| 2152 | * |
| 2153 | * A caller that doesn't care about the conflicting lock may pass NULL |
| 2154 | * as the final argument. |
| 2155 | * |
| 2156 | * If the filesystem defines a private ->lock() method, then @conf will |
| 2157 | * be left unchanged; so a caller that cares should initialize it to |
| 2158 | * some acceptable default. |
Marc Eshel | 2beb661 | 2006-12-05 23:31:28 -0500 | [diff] [blame] | 2159 | * |
| 2160 | * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX |
| 2161 | * locks, the ->lock() interface may return asynchronously, before the lock has |
| 2162 | * been granted or denied by the underlying filesystem, if (and only if) |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 2163 | * lm_grant is set. Callers expecting ->lock() to return asynchronously |
Marc Eshel | 2beb661 | 2006-12-05 23:31:28 -0500 | [diff] [blame] | 2164 | * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) |
| 2165 | * the request is for a blocking lock. When ->lock() does return asynchronously, |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 2166 | * it must return FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock |
Marc Eshel | 2beb661 | 2006-12-05 23:31:28 -0500 | [diff] [blame] | 2167 | * request completes. |
| 2168 | * If the request is for non-blocking lock the file system should return |
Miklos Szeredi | bde74e4 | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2169 | * FILE_LOCK_DEFERRED then try to get the lock and call the callback routine |
| 2170 | * with the result. If the request timed out the callback routine will return a |
Marc Eshel | 2beb661 | 2006-12-05 23:31:28 -0500 | [diff] [blame] | 2171 | * nonzero return code and the file system should release the lock. The file |
| 2172 | * system is also responsible to keep a corresponding posix lock when it |
| 2173 | * grants a lock so the VFS can find out which locks are locally held and do |
| 2174 | * the correct lock cleanup when required. |
| 2175 | * The underlying filesystem must not drop the kernel lock or call |
J. Bruce Fields | 8fb47a4 | 2011-07-20 20:21:59 -0400 | [diff] [blame] | 2176 | * ->lm_grant() before returning to the caller with a FILE_LOCK_DEFERRED |
Marc Eshel | 2beb661 | 2006-12-05 23:31:28 -0500 | [diff] [blame] | 2177 | * return code. |
Marc Eshel | 7723ec9 | 2007-01-18 15:08:55 -0500 | [diff] [blame] | 2178 | */ |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 2179 | int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf) |
Marc Eshel | 7723ec9 | 2007-01-18 15:08:55 -0500 | [diff] [blame] | 2180 | { |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2181 | if (filp->f_op->lock && is_remote_lock(filp)) |
Marc Eshel | 7723ec9 | 2007-01-18 15:08:55 -0500 | [diff] [blame] | 2182 | return filp->f_op->lock(filp, cmd, fl); |
| 2183 | else |
Marc Eshel | 150b393 | 2007-01-18 16:15:35 -0500 | [diff] [blame] | 2184 | return posix_lock_file(filp, fl, conf); |
Marc Eshel | 7723ec9 | 2007-01-18 15:08:55 -0500 | [diff] [blame] | 2185 | } |
| 2186 | EXPORT_SYMBOL_GPL(vfs_lock_file); |
| 2187 | |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2188 | static int do_lock_file_wait(struct file *filp, unsigned int cmd, |
| 2189 | struct file_lock *fl) |
| 2190 | { |
| 2191 | int error; |
| 2192 | |
| 2193 | error = security_file_lock(filp, fl->fl_type); |
| 2194 | if (error) |
| 2195 | return error; |
| 2196 | |
Miklos Szeredi | 764c76b | 2008-07-25 01:48:58 -0700 | [diff] [blame] | 2197 | for (;;) { |
| 2198 | error = vfs_lock_file(filp, cmd, fl, NULL); |
| 2199 | if (error != FILE_LOCK_DEFERRED) |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2200 | break; |
Miklos Szeredi | 764c76b | 2008-07-25 01:48:58 -0700 | [diff] [blame] | 2201 | error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); |
| 2202 | if (!error) |
| 2203 | continue; |
| 2204 | |
| 2205 | locks_delete_block(fl); |
| 2206 | break; |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2207 | } |
| 2208 | |
| 2209 | return error; |
| 2210 | } |
| 2211 | |
Benjamin Coddington | 6ca7d91 | 2015-10-15 09:07:07 -0400 | [diff] [blame] | 2212 | /* Ensure that fl->fl_file has compatible f_mode for F_SETLK calls */ |
Jeff Layton | cf01f4e | 2014-05-09 11:41:54 -0400 | [diff] [blame] | 2213 | static int |
| 2214 | check_fmode_for_setlk(struct file_lock *fl) |
| 2215 | { |
| 2216 | switch (fl->fl_type) { |
| 2217 | case F_RDLCK: |
| 2218 | if (!(fl->fl_file->f_mode & FMODE_READ)) |
| 2219 | return -EBADF; |
| 2220 | break; |
| 2221 | case F_WRLCK: |
| 2222 | if (!(fl->fl_file->f_mode & FMODE_WRITE)) |
| 2223 | return -EBADF; |
| 2224 | } |
| 2225 | return 0; |
| 2226 | } |
| 2227 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2228 | /* Apply the lock described by l to an open file descriptor. |
| 2229 | * This implements both the F_SETLK and F_SETLKW commands of fcntl(). |
| 2230 | */ |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2231 | int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2232 | struct flock *flock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2233 | { |
| 2234 | struct file_lock *file_lock = locks_alloc_lock(); |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2235 | struct inode *inode = locks_inode(filp); |
Al Viro | 0b2bac2 | 2008-05-06 13:58:34 -0400 | [diff] [blame] | 2236 | struct file *f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2237 | int error; |
| 2238 | |
| 2239 | if (file_lock == NULL) |
| 2240 | return -ENOLCK; |
| 2241 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2242 | /* Don't allow mandatory locks on files that may be memory mapped |
| 2243 | * and shared. |
| 2244 | */ |
Pavel Emelyanov | a16877c | 2007-10-01 14:41:11 -0700 | [diff] [blame] | 2245 | if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2246 | error = -EAGAIN; |
| 2247 | goto out; |
| 2248 | } |
| 2249 | |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2250 | error = flock_to_posix_lock(filp, file_lock, flock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2251 | if (error) |
| 2252 | goto out; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2253 | |
Jeff Layton | cf01f4e | 2014-05-09 11:41:54 -0400 | [diff] [blame] | 2254 | error = check_fmode_for_setlk(file_lock); |
| 2255 | if (error) |
| 2256 | goto out; |
| 2257 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2258 | /* |
| 2259 | * If the cmd is requesting file-private locks, then set the |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2260 | * FL_OFDLCK flag and override the owner. |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2261 | */ |
| 2262 | switch (cmd) { |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2263 | case F_OFD_SETLK: |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2264 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2265 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2266 | goto out; |
| 2267 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2268 | cmd = F_SETLK; |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2269 | file_lock->fl_flags |= FL_OFDLCK; |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 2270 | file_lock->fl_owner = filp; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2271 | break; |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2272 | case F_OFD_SETLKW: |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2273 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2274 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2275 | goto out; |
| 2276 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2277 | cmd = F_SETLKW; |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2278 | file_lock->fl_flags |= FL_OFDLCK; |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 2279 | file_lock->fl_owner = filp; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2280 | /* Fallthrough */ |
| 2281 | case F_SETLKW: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2282 | file_lock->fl_flags |= FL_SLEEP; |
| 2283 | } |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2284 | |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2285 | error = do_lock_file_wait(filp, cmd, file_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2286 | |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2287 | /* |
Jeff Layton | 0752ba8 | 2016-01-08 07:30:43 -0500 | [diff] [blame] | 2288 | * Attempt to detect a close/fcntl race and recover by releasing the |
| 2289 | * lock that was just acquired. There is no need to do that when we're |
| 2290 | * unlocking though, or for OFD locks. |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2291 | */ |
Jeff Layton | 0752ba8 | 2016-01-08 07:30:43 -0500 | [diff] [blame] | 2292 | if (!error && file_lock->fl_type != F_UNLCK && |
| 2293 | !(file_lock->fl_flags & FL_OFDLCK)) { |
Jeff Layton | 7f3697e | 2016-01-07 16:38:10 -0500 | [diff] [blame] | 2294 | /* |
| 2295 | * We need that spin_lock here - it prevents reordering between |
| 2296 | * update of i_flctx->flc_posix and check for it done in |
| 2297 | * close(). rcu_read_lock() wouldn't do. |
| 2298 | */ |
| 2299 | spin_lock(¤t->files->file_lock); |
| 2300 | f = fcheck(fd); |
| 2301 | spin_unlock(¤t->files->file_lock); |
| 2302 | if (f != filp) { |
| 2303 | file_lock->fl_type = F_UNLCK; |
| 2304 | error = do_lock_file_wait(filp, cmd, file_lock); |
| 2305 | WARN_ON_ONCE(error); |
| 2306 | error = -EBADF; |
| 2307 | } |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2308 | } |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2309 | out: |
Jeff Layton | 1890910 | 2016-01-06 21:26:10 -0500 | [diff] [blame] | 2310 | trace_fcntl_setlk(inode, file_lock, error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2311 | locks_free_lock(file_lock); |
| 2312 | return error; |
| 2313 | } |
| 2314 | |
| 2315 | #if BITS_PER_LONG == 32 |
| 2316 | /* Report the first existing lock that would conflict with l. |
| 2317 | * This implements the F_GETLK command of fcntl(). |
| 2318 | */ |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2319 | int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 *flock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2320 | { |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2321 | struct file_lock *fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2322 | int error; |
| 2323 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2324 | fl = locks_alloc_lock(); |
| 2325 | if (fl == NULL) |
| 2326 | return -ENOMEM; |
| 2327 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2328 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2329 | if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2330 | goto out; |
| 2331 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2332 | error = flock64_to_posix_lock(filp, fl, flock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2333 | if (error) |
| 2334 | goto out; |
| 2335 | |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2336 | if (cmd == F_OFD_GETLK) { |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2337 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2338 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2339 | goto out; |
| 2340 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2341 | cmd = F_GETLK64; |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2342 | fl->fl_flags |= FL_OFDLCK; |
| 2343 | fl->fl_owner = filp; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2344 | } |
| 2345 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2346 | error = vfs_test_lock(filp, fl); |
J. Bruce Fields | 3ee17ab | 2007-02-21 00:58:50 -0500 | [diff] [blame] | 2347 | if (error) |
| 2348 | goto out; |
| 2349 | |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2350 | flock->l_type = fl->fl_type; |
| 2351 | if (fl->fl_type != F_UNLCK) |
| 2352 | posix_lock_to_flock64(flock, fl); |
Kinglong Mee | f328296 | 2014-08-22 10:18:43 -0400 | [diff] [blame] | 2353 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2354 | out: |
Benjamin Coddington | 52306e8 | 2017-07-16 10:28:21 -0400 | [diff] [blame] | 2355 | locks_free_lock(fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2356 | return error; |
| 2357 | } |
| 2358 | |
| 2359 | /* Apply the lock described by l to an open file descriptor. |
| 2360 | * This implements both the F_SETLK and F_SETLKW commands of fcntl(). |
| 2361 | */ |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2362 | int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2363 | struct flock64 *flock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2364 | { |
| 2365 | struct file_lock *file_lock = locks_alloc_lock(); |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2366 | struct inode *inode = locks_inode(filp); |
Al Viro | 0b2bac2 | 2008-05-06 13:58:34 -0400 | [diff] [blame] | 2367 | struct file *f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2368 | int error; |
| 2369 | |
| 2370 | if (file_lock == NULL) |
| 2371 | return -ENOLCK; |
| 2372 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2373 | /* Don't allow mandatory locks on files that may be memory mapped |
| 2374 | * and shared. |
| 2375 | */ |
Pavel Emelyanov | a16877c | 2007-10-01 14:41:11 -0700 | [diff] [blame] | 2376 | if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2377 | error = -EAGAIN; |
| 2378 | goto out; |
| 2379 | } |
| 2380 | |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2381 | error = flock64_to_posix_lock(filp, file_lock, flock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2382 | if (error) |
| 2383 | goto out; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2384 | |
Jeff Layton | cf01f4e | 2014-05-09 11:41:54 -0400 | [diff] [blame] | 2385 | error = check_fmode_for_setlk(file_lock); |
| 2386 | if (error) |
| 2387 | goto out; |
| 2388 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2389 | /* |
| 2390 | * If the cmd is requesting file-private locks, then set the |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2391 | * FL_OFDLCK flag and override the owner. |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2392 | */ |
| 2393 | switch (cmd) { |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2394 | case F_OFD_SETLK: |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2395 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2396 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2397 | goto out; |
| 2398 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2399 | cmd = F_SETLK64; |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2400 | file_lock->fl_flags |= FL_OFDLCK; |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 2401 | file_lock->fl_owner = filp; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2402 | break; |
Jeff Layton | 0d3f7a2 | 2014-04-22 08:23:58 -0400 | [diff] [blame] | 2403 | case F_OFD_SETLKW: |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2404 | error = -EINVAL; |
Christoph Hellwig | a75d30c | 2017-05-27 06:07:19 -0400 | [diff] [blame] | 2405 | if (flock->l_pid != 0) |
Jeff Layton | 9047893 | 2014-03-04 10:30:23 -0500 | [diff] [blame] | 2406 | goto out; |
| 2407 | |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2408 | cmd = F_SETLKW64; |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2409 | file_lock->fl_flags |= FL_OFDLCK; |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 2410 | file_lock->fl_owner = filp; |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2411 | /* Fallthrough */ |
| 2412 | case F_SETLKW64: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2413 | file_lock->fl_flags |= FL_SLEEP; |
| 2414 | } |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2415 | |
Miklos Szeredi | b648a6d | 2008-07-25 01:48:57 -0700 | [diff] [blame] | 2416 | error = do_lock_file_wait(filp, cmd, file_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2417 | |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2418 | /* |
Jeff Layton | 0752ba8 | 2016-01-08 07:30:43 -0500 | [diff] [blame] | 2419 | * Attempt to detect a close/fcntl race and recover by releasing the |
| 2420 | * lock that was just acquired. There is no need to do that when we're |
| 2421 | * unlocking though, or for OFD locks. |
Peter Staubach | c293621 | 2005-07-27 11:45:09 -0700 | [diff] [blame] | 2422 | */ |
Jeff Layton | 0752ba8 | 2016-01-08 07:30:43 -0500 | [diff] [blame] | 2423 | if (!error && file_lock->fl_type != F_UNLCK && |
| 2424 | !(file_lock->fl_flags & FL_OFDLCK)) { |
Jeff Layton | 7f3697e | 2016-01-07 16:38:10 -0500 | [diff] [blame] | 2425 | /* |
| 2426 | * We need that spin_lock here - it prevents reordering between |
| 2427 | * update of i_flctx->flc_posix and check for it done in |
| 2428 | * close(). rcu_read_lock() wouldn't do. |
| 2429 | */ |
| 2430 | spin_lock(¤t->files->file_lock); |
| 2431 | f = fcheck(fd); |
| 2432 | spin_unlock(¤t->files->file_lock); |
| 2433 | if (f != filp) { |
| 2434 | file_lock->fl_type = F_UNLCK; |
| 2435 | error = do_lock_file_wait(filp, cmd, file_lock); |
| 2436 | WARN_ON_ONCE(error); |
| 2437 | error = -EBADF; |
| 2438 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2439 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2440 | out: |
| 2441 | locks_free_lock(file_lock); |
| 2442 | return error; |
| 2443 | } |
| 2444 | #endif /* BITS_PER_LONG == 32 */ |
| 2445 | |
| 2446 | /* |
| 2447 | * This function is called when the file is being removed |
| 2448 | * from the task's fd array. POSIX locks belonging to this task |
| 2449 | * are deleted at this time. |
| 2450 | */ |
| 2451 | void locks_remove_posix(struct file *filp, fl_owner_t owner) |
| 2452 | { |
Jeff Layton | 1890910 | 2016-01-06 21:26:10 -0500 | [diff] [blame] | 2453 | int error; |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2454 | struct inode *inode = locks_inode(filp); |
Miklos Szeredi | ff7b86b | 2006-06-23 02:05:11 -0700 | [diff] [blame] | 2455 | struct file_lock lock; |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2456 | struct file_lock_context *ctx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2457 | |
| 2458 | /* |
| 2459 | * If there are no locks held on this file, we don't need to call |
| 2460 | * posix_lock_file(). Another process could be setting a lock on this |
| 2461 | * file at the same time, but we wouldn't remove that lock anyway. |
| 2462 | */ |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2463 | ctx = smp_load_acquire(&inode->i_flctx); |
Jeff Layton | bd61e0a | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2464 | if (!ctx || list_empty(&ctx->flc_posix)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2465 | return; |
| 2466 | |
| 2467 | lock.fl_type = F_UNLCK; |
Miklos Szeredi | 75e1fcc | 2006-06-23 02:05:12 -0700 | [diff] [blame] | 2468 | lock.fl_flags = FL_POSIX | FL_CLOSE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2469 | lock.fl_start = 0; |
| 2470 | lock.fl_end = OFFSET_MAX; |
| 2471 | lock.fl_owner = owner; |
| 2472 | lock.fl_pid = current->tgid; |
| 2473 | lock.fl_file = filp; |
| 2474 | lock.fl_ops = NULL; |
| 2475 | lock.fl_lmops = NULL; |
| 2476 | |
Jeff Layton | 1890910 | 2016-01-06 21:26:10 -0500 | [diff] [blame] | 2477 | error = vfs_lock_file(filp, F_SETLK, &lock, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2478 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2479 | if (lock.fl_ops && lock.fl_ops->fl_release_private) |
| 2480 | lock.fl_ops->fl_release_private(&lock); |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2481 | trace_locks_remove_posix(inode, &lock, error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2482 | } |
| 2483 | |
| 2484 | EXPORT_SYMBOL(locks_remove_posix); |
| 2485 | |
Jeff Layton | 3d8e560 | 2015-01-16 15:05:58 -0500 | [diff] [blame] | 2486 | /* The i_flctx must be valid when calling into here */ |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2487 | static void |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2488 | locks_remove_flock(struct file *filp, struct file_lock_context *flctx) |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2489 | { |
| 2490 | struct file_lock fl = { |
| 2491 | .fl_owner = filp, |
| 2492 | .fl_pid = current->tgid, |
| 2493 | .fl_file = filp, |
Benjamin Coddington | 50f2112 | 2017-04-11 12:50:09 -0400 | [diff] [blame] | 2494 | .fl_flags = FL_FLOCK | FL_CLOSE, |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2495 | .fl_type = F_UNLCK, |
| 2496 | .fl_end = OFFSET_MAX, |
| 2497 | }; |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2498 | struct inode *inode = locks_inode(filp); |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2499 | |
Jeff Layton | 3d8e560 | 2015-01-16 15:05:58 -0500 | [diff] [blame] | 2500 | if (list_empty(&flctx->flc_flock)) |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2501 | return; |
| 2502 | |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2503 | if (filp->f_op->flock && is_remote_lock(filp)) |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2504 | filp->f_op->flock(filp, F_SETLKW, &fl); |
| 2505 | else |
Jeff Layton | bcd7f78 | 2015-07-11 06:43:02 -0400 | [diff] [blame] | 2506 | flock_lock_inode(inode, &fl); |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2507 | |
| 2508 | if (fl.fl_ops && fl.fl_ops->fl_release_private) |
| 2509 | fl.fl_ops->fl_release_private(&fl); |
| 2510 | } |
| 2511 | |
Jeff Layton | 3d8e560 | 2015-01-16 15:05:58 -0500 | [diff] [blame] | 2512 | /* The i_flctx must be valid when calling into here */ |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2513 | static void |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2514 | locks_remove_lease(struct file *filp, struct file_lock_context *ctx) |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2515 | { |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2516 | struct file_lock *fl, *tmp; |
| 2517 | LIST_HEAD(dispose); |
| 2518 | |
Jeff Layton | 3d8e560 | 2015-01-16 15:05:58 -0500 | [diff] [blame] | 2519 | if (list_empty(&ctx->flc_lease)) |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2520 | return; |
| 2521 | |
Peter Zijlstra | 5f43086 | 2016-10-08 10:12:28 +0200 | [diff] [blame] | 2522 | percpu_down_read_preempt_disable(&file_rwsem); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 2523 | spin_lock(&ctx->flc_lock); |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2524 | list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) |
Jeff Layton | c4e136c | 2015-02-16 19:37:42 -0500 | [diff] [blame] | 2525 | if (filp == fl->fl_file) |
| 2526 | lease_modify(fl, F_UNLCK, &dispose); |
Jeff Layton | 6109c85 | 2015-01-16 15:05:57 -0500 | [diff] [blame] | 2527 | spin_unlock(&ctx->flc_lock); |
Peter Zijlstra | 5f43086 | 2016-10-08 10:12:28 +0200 | [diff] [blame] | 2528 | percpu_up_read_preempt_enable(&file_rwsem); |
| 2529 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2530 | locks_dispose_list(&dispose); |
| 2531 | } |
| 2532 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2533 | /* |
| 2534 | * This function is called on the last close of an open file. |
| 2535 | */ |
Jeff Layton | 78ed8a1 | 2014-02-03 12:13:08 -0500 | [diff] [blame] | 2536 | void locks_remove_file(struct file *filp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2537 | { |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2538 | struct file_lock_context *ctx; |
| 2539 | |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2540 | ctx = smp_load_acquire(&locks_inode(filp)->i_flctx); |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2541 | if (!ctx) |
Jeff Layton | 3d8e560 | 2015-01-16 15:05:58 -0500 | [diff] [blame] | 2542 | return; |
| 2543 | |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2544 | /* remove any OFD locks */ |
Christoph Hellwig | 73a8f5f | 2014-07-13 17:00:38 +0200 | [diff] [blame] | 2545 | locks_remove_posix(filp, filp); |
Jeff Layton | 5d50ffd | 2014-02-03 12:13:10 -0500 | [diff] [blame] | 2546 | |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2547 | /* remove flock locks */ |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2548 | locks_remove_flock(filp, ctx); |
Jeff Layton | dd459bb | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2549 | |
Jeff Layton | 8634b51 | 2015-01-16 15:05:55 -0500 | [diff] [blame] | 2550 | /* remove any leases */ |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2551 | locks_remove_lease(filp, ctx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2552 | } |
| 2553 | |
| 2554 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2555 | * posix_unblock_lock - stop waiting for a file lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2556 | * @waiter: the lock which was waiting |
| 2557 | * |
| 2558 | * lockd needs to block waiting for locks. |
| 2559 | */ |
J. Bruce Fields | 64a318e | 2006-01-03 09:55:46 +0100 | [diff] [blame] | 2560 | int |
Jeff Layton | f891a29 | 2013-06-21 08:58:09 -0400 | [diff] [blame] | 2561 | posix_unblock_lock(struct file_lock *waiter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2562 | { |
J. Bruce Fields | 64a318e | 2006-01-03 09:55:46 +0100 | [diff] [blame] | 2563 | int status = 0; |
| 2564 | |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 2565 | spin_lock(&blocked_lock_lock); |
J. Bruce Fields | 5996a29 | 2006-01-03 09:55:44 +0100 | [diff] [blame] | 2566 | if (waiter->fl_next) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2567 | __locks_delete_block(waiter); |
J. Bruce Fields | 64a318e | 2006-01-03 09:55:46 +0100 | [diff] [blame] | 2568 | else |
| 2569 | status = -ENOENT; |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 2570 | spin_unlock(&blocked_lock_lock); |
J. Bruce Fields | 64a318e | 2006-01-03 09:55:46 +0100 | [diff] [blame] | 2571 | return status; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2572 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2573 | EXPORT_SYMBOL(posix_unblock_lock); |
| 2574 | |
Marc Eshel | 9b9d2ab | 2007-01-18 17:52:58 -0500 | [diff] [blame] | 2575 | /** |
| 2576 | * vfs_cancel_lock - file byte range unblock lock |
| 2577 | * @filp: The file to apply the unblock to |
| 2578 | * @fl: The lock to be unblocked |
| 2579 | * |
| 2580 | * Used by lock managers to cancel blocked requests |
| 2581 | */ |
| 2582 | int vfs_cancel_lock(struct file *filp, struct file_lock *fl) |
| 2583 | { |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2584 | if (filp->f_op->lock && is_remote_lock(filp)) |
Marc Eshel | 9b9d2ab | 2007-01-18 17:52:58 -0500 | [diff] [blame] | 2585 | return filp->f_op->lock(filp, F_CANCELLK, fl); |
| 2586 | return 0; |
| 2587 | } |
| 2588 | |
| 2589 | EXPORT_SYMBOL_GPL(vfs_cancel_lock); |
| 2590 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2591 | #ifdef CONFIG_PROC_FS |
Alexey Dobriyan | d8ba7a3 | 2008-10-04 22:34:18 +0400 | [diff] [blame] | 2592 | #include <linux/proc_fs.h> |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2593 | #include <linux/seq_file.h> |
| 2594 | |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2595 | struct locks_iterator { |
| 2596 | int li_cpu; |
| 2597 | loff_t li_pos; |
| 2598 | }; |
| 2599 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2600 | static void lock_get_status(struct seq_file *f, struct file_lock *fl, |
Jerome Marchand | 99dc829 | 2010-10-26 14:22:33 -0700 | [diff] [blame] | 2601 | loff_t id, char *pfx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2602 | { |
| 2603 | struct inode *inode = NULL; |
Vitaliy Gusev | ab1f161 | 2008-01-17 00:07:08 +0000 | [diff] [blame] | 2604 | unsigned int fl_pid; |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame^] | 2605 | struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; |
Vitaliy Gusev | ab1f161 | 2008-01-17 00:07:08 +0000 | [diff] [blame] | 2606 | |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame^] | 2607 | fl_pid = locks_translate_pid(fl, proc_pidns); |
| 2608 | /* |
| 2609 | * If there isn't a fl_pid don't display who is waiting on |
| 2610 | * the lock if we are called from locks_show, or if we are |
| 2611 | * called from __show_fd_info - skip lock entirely |
| 2612 | */ |
| 2613 | if (fl_pid == 0) |
| 2614 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2615 | |
| 2616 | if (fl->fl_file != NULL) |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2617 | inode = locks_inode(fl->fl_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2618 | |
Jerome Marchand | 99dc829 | 2010-10-26 14:22:33 -0700 | [diff] [blame] | 2619 | seq_printf(f, "%lld:%s ", id, pfx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2620 | if (IS_POSIX(fl)) { |
Jeff Layton | c918d42 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 2621 | if (fl->fl_flags & FL_ACCESS) |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2622 | seq_puts(f, "ACCESS"); |
Jeff Layton | cff2fce | 2014-04-22 08:24:32 -0400 | [diff] [blame] | 2623 | else if (IS_OFDLCK(fl)) |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2624 | seq_puts(f, "OFDLCK"); |
Jeff Layton | c918d42 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 2625 | else |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2626 | seq_puts(f, "POSIX "); |
Jeff Layton | c918d42 | 2014-02-03 12:13:09 -0500 | [diff] [blame] | 2627 | |
| 2628 | seq_printf(f, " %s ", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2629 | (inode == NULL) ? "*NOINODE*" : |
Pavel Emelyanov | a16877c | 2007-10-01 14:41:11 -0700 | [diff] [blame] | 2630 | mandatory_lock(inode) ? "MANDATORY" : "ADVISORY "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2631 | } else if (IS_FLOCK(fl)) { |
| 2632 | if (fl->fl_type & LOCK_MAND) { |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2633 | seq_puts(f, "FLOCK MSNFS "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2634 | } else { |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2635 | seq_puts(f, "FLOCK ADVISORY "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2636 | } |
| 2637 | } else if (IS_LEASE(fl)) { |
Jeff Layton | 8144f1f | 2014-08-11 13:36:54 -0400 | [diff] [blame] | 2638 | if (fl->fl_flags & FL_DELEG) |
| 2639 | seq_puts(f, "DELEG "); |
| 2640 | else |
| 2641 | seq_puts(f, "LEASE "); |
| 2642 | |
J. Bruce Fields | ab83fa4 | 2011-07-26 20:10:51 -0400 | [diff] [blame] | 2643 | if (lease_breaking(fl)) |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2644 | seq_puts(f, "BREAKING "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2645 | else if (fl->fl_file) |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2646 | seq_puts(f, "ACTIVE "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2647 | else |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2648 | seq_puts(f, "BREAKER "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2649 | } else { |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2650 | seq_puts(f, "UNKNOWN UNKNOWN "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2651 | } |
| 2652 | if (fl->fl_type & LOCK_MAND) { |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2653 | seq_printf(f, "%s ", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2654 | (fl->fl_type & LOCK_READ) |
| 2655 | ? (fl->fl_type & LOCK_WRITE) ? "RW " : "READ " |
| 2656 | : (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE "); |
| 2657 | } else { |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2658 | seq_printf(f, "%s ", |
J. Bruce Fields | ab83fa4 | 2011-07-26 20:10:51 -0400 | [diff] [blame] | 2659 | (lease_breaking(fl)) |
Jeff Layton | 0ee5c6d | 2012-08-02 15:46:30 -0400 | [diff] [blame] | 2660 | ? (fl->fl_type == F_UNLCK) ? "UNLCK" : "READ " |
| 2661 | : (fl->fl_type == F_WRLCK) ? "WRITE" : "READ "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2662 | } |
| 2663 | if (inode) { |
Jeff Layton | 3648888 | 2015-04-03 09:04:04 -0400 | [diff] [blame] | 2664 | /* userspace relies on this representation of dev_t */ |
Vitaliy Gusev | ab1f161 | 2008-01-17 00:07:08 +0000 | [diff] [blame] | 2665 | seq_printf(f, "%d %02x:%02x:%ld ", fl_pid, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2666 | MAJOR(inode->i_sb->s_dev), |
| 2667 | MINOR(inode->i_sb->s_dev), inode->i_ino); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2668 | } else { |
Vitaliy Gusev | ab1f161 | 2008-01-17 00:07:08 +0000 | [diff] [blame] | 2669 | seq_printf(f, "%d <none>:0 ", fl_pid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2670 | } |
| 2671 | if (IS_POSIX(fl)) { |
| 2672 | if (fl->fl_end == OFFSET_MAX) |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2673 | seq_printf(f, "%Ld EOF\n", fl->fl_start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2674 | else |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2675 | seq_printf(f, "%Ld %Ld\n", fl->fl_start, fl->fl_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2676 | } else { |
Fabian Frederick | 5315c26 | 2014-05-09 14:13:05 -0400 | [diff] [blame] | 2677 | seq_puts(f, "0 EOF\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2678 | } |
| 2679 | } |
| 2680 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2681 | static int locks_show(struct seq_file *f, void *v) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2682 | { |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2683 | struct locks_iterator *iter = f->private; |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2684 | struct file_lock *fl, *bfl; |
Nikolay Borisov | d67fd44 | 2016-08-17 16:18:46 -0400 | [diff] [blame] | 2685 | struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2686 | |
Jeff Layton | 139ca04 | 2013-06-21 08:58:17 -0400 | [diff] [blame] | 2687 | fl = hlist_entry(v, struct file_lock, fl_link); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2688 | |
Benjamin Coddington | 9d5b86a | 2017-07-16 10:28:22 -0400 | [diff] [blame^] | 2689 | if (locks_translate_pid(fl, proc_pidns) == 0) |
Nikolay Borisov | d67fd44 | 2016-08-17 16:18:46 -0400 | [diff] [blame] | 2690 | return 0; |
| 2691 | |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2692 | lock_get_status(f, fl, iter->li_pos, ""); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2693 | |
| 2694 | list_for_each_entry(bfl, &fl->fl_block, fl_block) |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2695 | lock_get_status(f, bfl, iter->li_pos, " ->"); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2696 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2697 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2698 | } |
| 2699 | |
Andrey Vagin | 6c8c903 | 2015-04-16 12:49:38 -0700 | [diff] [blame] | 2700 | static void __show_fd_locks(struct seq_file *f, |
| 2701 | struct list_head *head, int *id, |
| 2702 | struct file *filp, struct files_struct *files) |
| 2703 | { |
| 2704 | struct file_lock *fl; |
| 2705 | |
| 2706 | list_for_each_entry(fl, head, fl_list) { |
| 2707 | |
| 2708 | if (filp != fl->fl_file) |
| 2709 | continue; |
| 2710 | if (fl->fl_owner != files && |
| 2711 | fl->fl_owner != filp) |
| 2712 | continue; |
| 2713 | |
| 2714 | (*id)++; |
| 2715 | seq_puts(f, "lock:\t"); |
| 2716 | lock_get_status(f, fl, *id, ""); |
| 2717 | } |
| 2718 | } |
| 2719 | |
| 2720 | void show_fd_locks(struct seq_file *f, |
| 2721 | struct file *filp, struct files_struct *files) |
| 2722 | { |
Miklos Szeredi | c568d68 | 2016-09-16 12:44:20 +0200 | [diff] [blame] | 2723 | struct inode *inode = locks_inode(filp); |
Andrey Vagin | 6c8c903 | 2015-04-16 12:49:38 -0700 | [diff] [blame] | 2724 | struct file_lock_context *ctx; |
| 2725 | int id = 0; |
| 2726 | |
Dmitry Vyukov | 128a378 | 2015-09-21 09:43:06 +0200 | [diff] [blame] | 2727 | ctx = smp_load_acquire(&inode->i_flctx); |
Andrey Vagin | 6c8c903 | 2015-04-16 12:49:38 -0700 | [diff] [blame] | 2728 | if (!ctx) |
| 2729 | return; |
| 2730 | |
| 2731 | spin_lock(&ctx->flc_lock); |
| 2732 | __show_fd_locks(f, &ctx->flc_flock, &id, filp, files); |
| 2733 | __show_fd_locks(f, &ctx->flc_posix, &id, filp, files); |
| 2734 | __show_fd_locks(f, &ctx->flc_lease, &id, filp, files); |
| 2735 | spin_unlock(&ctx->flc_lock); |
| 2736 | } |
| 2737 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2738 | static void *locks_start(struct seq_file *f, loff_t *pos) |
Jeff Layton | b03dfdec | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 2739 | __acquires(&blocked_lock_lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2740 | { |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2741 | struct locks_iterator *iter = f->private; |
Jerome Marchand | 99dc829 | 2010-10-26 14:22:33 -0700 | [diff] [blame] | 2742 | |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2743 | iter->li_pos = *pos + 1; |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 2744 | percpu_down_write(&file_rwsem); |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 2745 | spin_lock(&blocked_lock_lock); |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 2746 | return seq_hlist_start_percpu(&file_lock_list.hlist, &iter->li_cpu, *pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2747 | } |
| 2748 | |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2749 | static void *locks_next(struct seq_file *f, void *v, loff_t *pos) |
| 2750 | { |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2751 | struct locks_iterator *iter = f->private; |
| 2752 | |
| 2753 | ++iter->li_pos; |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 2754 | return seq_hlist_next_percpu(v, &file_lock_list.hlist, &iter->li_cpu, pos); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2755 | } |
| 2756 | |
| 2757 | static void locks_stop(struct seq_file *f, void *v) |
Jeff Layton | b03dfdec | 2014-02-03 12:13:07 -0500 | [diff] [blame] | 2758 | __releases(&blocked_lock_lock) |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2759 | { |
Jeff Layton | 7b2296a | 2013-06-21 08:58:20 -0400 | [diff] [blame] | 2760 | spin_unlock(&blocked_lock_lock); |
Peter Zijlstra | aba3766 | 2015-06-22 14:16:33 +0200 | [diff] [blame] | 2761 | percpu_up_write(&file_rwsem); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2762 | } |
| 2763 | |
Alexey Dobriyan | d8ba7a3 | 2008-10-04 22:34:18 +0400 | [diff] [blame] | 2764 | static const struct seq_operations locks_seq_operations = { |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2765 | .start = locks_start, |
| 2766 | .next = locks_next, |
| 2767 | .stop = locks_stop, |
| 2768 | .show = locks_show, |
| 2769 | }; |
Alexey Dobriyan | d8ba7a3 | 2008-10-04 22:34:18 +0400 | [diff] [blame] | 2770 | |
| 2771 | static int locks_open(struct inode *inode, struct file *filp) |
| 2772 | { |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2773 | return seq_open_private(filp, &locks_seq_operations, |
| 2774 | sizeof(struct locks_iterator)); |
Alexey Dobriyan | d8ba7a3 | 2008-10-04 22:34:18 +0400 | [diff] [blame] | 2775 | } |
| 2776 | |
| 2777 | static const struct file_operations proc_locks_operations = { |
| 2778 | .open = locks_open, |
| 2779 | .read = seq_read, |
| 2780 | .llseek = seq_lseek, |
Jerome Marchand | 99dc829 | 2010-10-26 14:22:33 -0700 | [diff] [blame] | 2781 | .release = seq_release_private, |
Alexey Dobriyan | d8ba7a3 | 2008-10-04 22:34:18 +0400 | [diff] [blame] | 2782 | }; |
| 2783 | |
| 2784 | static int __init proc_locks_init(void) |
| 2785 | { |
| 2786 | proc_create("locks", 0, NULL, &proc_locks_operations); |
| 2787 | return 0; |
| 2788 | } |
Paul Gortmaker | 9189922 | 2015-12-17 14:11:03 -0500 | [diff] [blame] | 2789 | fs_initcall(proc_locks_init); |
Pavel Emelyanov | 7f8ada9 | 2007-10-01 14:41:15 -0700 | [diff] [blame] | 2790 | #endif |
| 2791 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2792 | static int __init filelock_init(void) |
| 2793 | { |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2794 | int i; |
| 2795 | |
Jeff Layton | 4a075e3 | 2015-01-16 15:05:54 -0500 | [diff] [blame] | 2796 | flctx_cache = kmem_cache_create("file_lock_ctx", |
| 2797 | sizeof(struct file_lock_context), 0, SLAB_PANIC, NULL); |
| 2798 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2799 | filelock_cache = kmem_cache_create("file_lock_cache", |
Miklos Szeredi | ee19cc4 | 2011-07-07 13:06:09 +0200 | [diff] [blame] | 2800 | sizeof(struct file_lock), 0, SLAB_PANIC, NULL); |
| 2801 | |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2802 | |
Peter Zijlstra | 7c3f654 | 2015-06-22 14:16:34 +0200 | [diff] [blame] | 2803 | for_each_possible_cpu(i) { |
| 2804 | struct file_lock_list_struct *fll = per_cpu_ptr(&file_lock_list, i); |
| 2805 | |
| 2806 | spin_lock_init(&fll->lock); |
| 2807 | INIT_HLIST_HEAD(&fll->hlist); |
| 2808 | } |
Jeff Layton | 7012b02 | 2013-06-21 08:58:22 -0400 | [diff] [blame] | 2809 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2810 | return 0; |
| 2811 | } |
| 2812 | |
| 2813 | core_initcall(filelock_init); |