Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/lockd/svclock.c |
| 3 | * |
| 4 | * Handling of server-side locks, mostly of the blocked variety. |
| 5 | * This is the ugliest part of lockd because we tread on very thin ice. |
| 6 | * GRANT and CANCEL calls may get stuck, meet in mid-flight, etc. |
| 7 | * IMNSHO introducing the grant callback into the NLM protocol was one |
| 8 | * of the worst ideas Sun ever had. Except maybe for the idea of doing |
| 9 | * NFS file locking at all. |
| 10 | * |
| 11 | * I'm trying hard to avoid race conditions by protecting most accesses |
| 12 | * to a file's list of blocked locks through a semaphore. The global |
| 13 | * list of blocked locks is not protected in this fashion however. |
| 14 | * Therefore, some functions (such as the RPC callback for the async grant |
| 15 | * call) move blocked locks towards the head of the list *while some other |
| 16 | * process might be traversing it*. This should not be a problem in |
| 17 | * practice, because this will only cause functions traversing the list |
| 18 | * to visit some blocks twice. |
| 19 | * |
| 20 | * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> |
| 21 | */ |
| 22 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <linux/types.h> |
| 24 | #include <linux/errno.h> |
| 25 | #include <linux/kernel.h> |
| 26 | #include <linux/sched.h> |
| 27 | #include <linux/smp_lock.h> |
| 28 | #include <linux/sunrpc/clnt.h> |
| 29 | #include <linux/sunrpc/svc.h> |
| 30 | #include <linux/lockd/nlm.h> |
| 31 | #include <linux/lockd/lockd.h> |
| 32 | |
| 33 | #define NLMDBG_FACILITY NLMDBG_SVCLOCK |
| 34 | |
| 35 | #ifdef CONFIG_LOCKD_V4 |
| 36 | #define nlm_deadlock nlm4_deadlock |
| 37 | #else |
| 38 | #define nlm_deadlock nlm_lck_denied |
| 39 | #endif |
| 40 | |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 41 | static void nlmsvc_release_block(struct nlm_block *block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | static void nlmsvc_insert_block(struct nlm_block *block, unsigned long); |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 43 | static void nlmsvc_remove_block(struct nlm_block *block); |
Trond Myklebust | 963d8fe | 2006-01-03 09:55:04 +0100 | [diff] [blame] | 44 | |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 45 | static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock); |
| 46 | static void nlmsvc_freegrantargs(struct nlm_rqst *call); |
Trond Myklebust | 963d8fe | 2006-01-03 09:55:04 +0100 | [diff] [blame] | 47 | static const struct rpc_call_ops nlmsvc_grant_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
| 49 | /* |
| 50 | * The list of blocked locks to retry |
| 51 | */ |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 52 | static LIST_HEAD(nlm_blocked); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
| 54 | /* |
| 55 | * Insert a blocked lock into the global list |
| 56 | */ |
| 57 | static void |
| 58 | nlmsvc_insert_block(struct nlm_block *block, unsigned long when) |
| 59 | { |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 60 | struct nlm_block *b; |
| 61 | struct list_head *pos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
| 63 | dprintk("lockd: nlmsvc_insert_block(%p, %ld)\n", block, when); |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 64 | if (list_empty(&block->b_list)) { |
| 65 | kref_get(&block->b_count); |
| 66 | } else { |
| 67 | list_del_init(&block->b_list); |
| 68 | } |
| 69 | |
| 70 | pos = &nlm_blocked; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | if (when != NLM_NEVER) { |
| 72 | if ((when += jiffies) == NLM_NEVER) |
| 73 | when ++; |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 74 | list_for_each(pos, &nlm_blocked) { |
| 75 | b = list_entry(pos, struct nlm_block, b_list); |
| 76 | if (time_after(b->b_when,when) || b->b_when == NLM_NEVER) |
| 77 | break; |
| 78 | } |
| 79 | /* On normal exit from the loop, pos == &nlm_blocked, |
| 80 | * so we will be adding to the end of the list - good |
| 81 | */ |
| 82 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 84 | list_add_tail(&block->b_list, pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | block->b_when = when; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | } |
| 87 | |
| 88 | /* |
| 89 | * Remove a block from the global list |
| 90 | */ |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 91 | static inline void |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | nlmsvc_remove_block(struct nlm_block *block) |
| 93 | { |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 94 | if (!list_empty(&block->b_list)) { |
| 95 | list_del_init(&block->b_list); |
| 96 | nlmsvc_release_block(block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | } |
| 99 | |
| 100 | /* |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 101 | * Find a block for a given lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | */ |
| 103 | static struct nlm_block * |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 104 | nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | { |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 106 | struct nlm_block *block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | struct file_lock *fl; |
| 108 | |
| 109 | dprintk("lockd: nlmsvc_lookup_block f=%p pd=%d %Ld-%Ld ty=%d\n", |
| 110 | file, lock->fl.fl_pid, |
| 111 | (long long)lock->fl.fl_start, |
| 112 | (long long)lock->fl.fl_end, lock->fl.fl_type); |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 113 | list_for_each_entry(block, &nlm_blocked, b_list) { |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 114 | fl = &block->b_call->a_args.lock.fl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | dprintk("lockd: check f=%p pd=%d %Ld-%Ld ty=%d cookie=%s\n", |
| 116 | block->b_file, fl->fl_pid, |
| 117 | (long long)fl->fl_start, |
| 118 | (long long)fl->fl_end, fl->fl_type, |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 119 | nlmdbg_cookie2a(&block->b_call->a_args.cookie)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | if (block->b_file == file && nlm_compare_locks(fl, &lock->fl)) { |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 121 | kref_get(&block->b_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | return block; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | return NULL; |
| 127 | } |
| 128 | |
| 129 | static inline int nlm_cookie_match(struct nlm_cookie *a, struct nlm_cookie *b) |
| 130 | { |
| 131 | if(a->len != b->len) |
| 132 | return 0; |
| 133 | if(memcmp(a->data,b->data,a->len)) |
| 134 | return 0; |
| 135 | return 1; |
| 136 | } |
| 137 | |
| 138 | /* |
| 139 | * Find a block with a given NLM cookie. |
| 140 | */ |
| 141 | static inline struct nlm_block * |
Olaf Kirch | 39be450 | 2006-10-04 02:16:03 -0700 | [diff] [blame] | 142 | nlmsvc_find_block(struct nlm_cookie *cookie) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | { |
| 144 | struct nlm_block *block; |
| 145 | |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 146 | list_for_each_entry(block, &nlm_blocked, b_list) { |
Olaf Kirch | 39be450 | 2006-10-04 02:16:03 -0700 | [diff] [blame] | 147 | if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie)) |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 148 | goto found; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | } |
| 150 | |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 151 | return NULL; |
| 152 | |
| 153 | found: |
Olaf Kirch | 39be450 | 2006-10-04 02:16:03 -0700 | [diff] [blame] | 154 | dprintk("nlmsvc_find_block(%s): block=%p\n", nlmdbg_cookie2a(cookie), block); |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 155 | kref_get(&block->b_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | return block; |
| 157 | } |
| 158 | |
| 159 | /* |
| 160 | * Create a block and initialize it. |
| 161 | * |
| 162 | * Note: we explicitly set the cookie of the grant reply to that of |
| 163 | * the blocked lock request. The spec explicitly mentions that the client |
| 164 | * should _not_ rely on the callback containing the same cookie as the |
| 165 | * request, but (as I found out later) that's because some implementations |
| 166 | * do just this. Never mind the standards comittees, they support our |
| 167 | * logging industries. |
Olaf Kirch | 39be450 | 2006-10-04 02:16:03 -0700 | [diff] [blame] | 168 | * |
| 169 | * 10 years later: I hope we can safely ignore these old and broken |
| 170 | * clients by now. Let's fix this so we can uniquely identify an incoming |
| 171 | * GRANTED_RES message by cookie, without having to rely on the client's IP |
| 172 | * address. --okir |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | */ |
Trond Myklebust | 255129d | 2007-09-25 15:55:03 -0400 | [diff] [blame] | 174 | static struct nlm_block * |
| 175 | nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host, |
| 176 | struct nlm_file *file, struct nlm_lock *lock, |
| 177 | struct nlm_cookie *cookie) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | { |
| 179 | struct nlm_block *block; |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 180 | struct nlm_rqst *call = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 182 | call = nlm_alloc_call(host); |
| 183 | if (call == NULL) |
| 184 | return NULL; |
| 185 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | /* Allocate memory for block, and initialize arguments */ |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 187 | block = kzalloc(sizeof(*block), GFP_KERNEL); |
| 188 | if (block == NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | goto failed; |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 190 | kref_init(&block->b_count); |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 191 | INIT_LIST_HEAD(&block->b_list); |
| 192 | INIT_LIST_HEAD(&block->b_flist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 194 | if (!nlmsvc_setgrantargs(call, lock)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | goto failed_free; |
| 196 | |
| 197 | /* Set notifier function for VFS, and init args */ |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 198 | call->a_args.lock.fl.fl_flags |= FL_SLEEP; |
| 199 | call->a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations; |
Olaf Kirch | 39be450 | 2006-10-04 02:16:03 -0700 | [diff] [blame] | 200 | nlmclnt_next_cookie(&call->a_args.cookie); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | |
| 202 | dprintk("lockd: created block %p...\n", block); |
| 203 | |
| 204 | /* Create and initialize the block */ |
| 205 | block->b_daemon = rqstp->rq_server; |
| 206 | block->b_host = host; |
| 207 | block->b_file = file; |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 208 | block->b_fl = NULL; |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 209 | file->f_count++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | |
| 211 | /* Add to file's list of blocks */ |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 212 | list_add(&block->b_flist, &file->f_blocks); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | |
| 214 | /* Set up RPC arguments for callback */ |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 215 | block->b_call = call; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | call->a_flags = RPC_TASK_ASYNC; |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 217 | call->a_block = block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | |
| 219 | return block; |
| 220 | |
| 221 | failed_free: |
| 222 | kfree(block); |
| 223 | failed: |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 224 | nlm_release_call(call); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | return NULL; |
| 226 | } |
| 227 | |
| 228 | /* |
| 229 | * Delete a block. If the lock was cancelled or the grant callback |
| 230 | * failed, unlock is set to 1. |
| 231 | * It is the caller's responsibility to check whether the file |
| 232 | * can be closed hereafter. |
| 233 | */ |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 234 | static int nlmsvc_unlink_block(struct nlm_block *block) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | { |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 236 | int status; |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 237 | dprintk("lockd: unlinking block %p...\n", block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | |
| 239 | /* Remove block from list */ |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 240 | status = posix_unblock_lock(block->b_file->f_file, &block->b_call->a_args.lock.fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | nlmsvc_remove_block(block); |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 242 | return status; |
| 243 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 245 | static void nlmsvc_free_block(struct kref *kref) |
| 246 | { |
| 247 | struct nlm_block *block = container_of(kref, struct nlm_block, b_count); |
| 248 | struct nlm_file *file = block->b_file; |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 249 | |
| 250 | dprintk("lockd: freeing block %p...\n", block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | |
| 252 | /* Remove block from file's list of blocks */ |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 253 | mutex_lock(&file->f_mutex); |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 254 | list_del_init(&block->b_flist); |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 255 | mutex_unlock(&file->f_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 257 | nlmsvc_freegrantargs(block->b_call); |
| 258 | nlm_release_call(block->b_call); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 259 | nlm_release_file(block->b_file); |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 260 | kfree(block->b_fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | kfree(block); |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 262 | } |
| 263 | |
| 264 | static void nlmsvc_release_block(struct nlm_block *block) |
| 265 | { |
| 266 | if (block != NULL) |
| 267 | kref_put(&block->b_count, nlmsvc_free_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | } |
| 269 | |
Olaf Kirch | f2af793 | 2006-10-04 02:15:59 -0700 | [diff] [blame] | 270 | /* |
| 271 | * Loop over all blocks and delete blocks held by |
| 272 | * a matching host. |
| 273 | */ |
| 274 | void nlmsvc_traverse_blocks(struct nlm_host *host, |
| 275 | struct nlm_file *file, |
| 276 | nlm_host_match_fn_t match) |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 277 | { |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 278 | struct nlm_block *block, *next; |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 279 | |
| 280 | restart: |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 281 | mutex_lock(&file->f_mutex); |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 282 | list_for_each_entry_safe(block, next, &file->f_blocks, b_flist) { |
Olaf Kirch | f2af793 | 2006-10-04 02:15:59 -0700 | [diff] [blame] | 283 | if (!match(block->b_host, host)) |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 284 | continue; |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 285 | /* Do not destroy blocks that are not on |
| 286 | * the global retry list - why? */ |
| 287 | if (list_empty(&block->b_list)) |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 288 | continue; |
| 289 | kref_get(&block->b_count); |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 290 | mutex_unlock(&file->f_mutex); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 291 | nlmsvc_unlink_block(block); |
| 292 | nlmsvc_release_block(block); |
| 293 | goto restart; |
| 294 | } |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 295 | mutex_unlock(&file->f_mutex); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 296 | } |
| 297 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | /* |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 299 | * Initialize arguments for GRANTED call. The nlm_rqst structure |
| 300 | * has been cleared already. |
| 301 | */ |
| 302 | static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock) |
| 303 | { |
| 304 | locks_copy_lock(&call->a_args.lock.fl, &lock->fl); |
| 305 | memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh)); |
Serge E. Hallyn | e9ff399 | 2006-10-02 02:18:11 -0700 | [diff] [blame] | 306 | call->a_args.lock.caller = utsname()->nodename; |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 307 | call->a_args.lock.oh.len = lock->oh.len; |
| 308 | |
| 309 | /* set default data area */ |
| 310 | call->a_args.lock.oh.data = call->a_owner; |
| 311 | call->a_args.lock.svid = lock->fl.fl_pid; |
| 312 | |
| 313 | if (lock->oh.len > NLMCLNT_OHSIZE) { |
| 314 | void *data = kmalloc(lock->oh.len, GFP_KERNEL); |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 315 | if (!data) |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 316 | return 0; |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 317 | call->a_args.lock.oh.data = (u8 *) data; |
| 318 | } |
| 319 | |
| 320 | memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len); |
| 321 | return 1; |
| 322 | } |
| 323 | |
| 324 | static void nlmsvc_freegrantargs(struct nlm_rqst *call) |
| 325 | { |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 326 | if (call->a_args.lock.oh.data != call->a_owner) |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 327 | kfree(call->a_args.lock.oh.data); |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 328 | } |
| 329 | |
| 330 | /* |
Marc Eshel | 2b36f41 | 2006-11-28 16:26:47 -0500 | [diff] [blame] | 331 | * Deferred lock request handling for non-blocking lock |
| 332 | */ |
Al Viro | ca5c8cd | 2007-07-26 17:33:49 +0100 | [diff] [blame] | 333 | static __be32 |
Marc Eshel | 2b36f41 | 2006-11-28 16:26:47 -0500 | [diff] [blame] | 334 | nlmsvc_defer_lock_rqst(struct svc_rqst *rqstp, struct nlm_block *block) |
| 335 | { |
Al Viro | ca5c8cd | 2007-07-26 17:33:49 +0100 | [diff] [blame] | 336 | __be32 status = nlm_lck_denied_nolocks; |
Marc Eshel | 2b36f41 | 2006-11-28 16:26:47 -0500 | [diff] [blame] | 337 | |
| 338 | block->b_flags |= B_QUEUED; |
| 339 | |
| 340 | nlmsvc_insert_block(block, NLM_TIMEOUT); |
| 341 | |
| 342 | block->b_cache_req = &rqstp->rq_chandle; |
| 343 | if (rqstp->rq_chandle.defer) { |
| 344 | block->b_deferred_req = |
| 345 | rqstp->rq_chandle.defer(block->b_cache_req); |
| 346 | if (block->b_deferred_req != NULL) |
| 347 | status = nlm_drop_reply; |
| 348 | } |
| 349 | dprintk("lockd: nlmsvc_defer_lock_rqst block %p flags %d status %d\n", |
Al Viro | ca5c8cd | 2007-07-26 17:33:49 +0100 | [diff] [blame] | 350 | block, block->b_flags, ntohl(status)); |
Marc Eshel | 2b36f41 | 2006-11-28 16:26:47 -0500 | [diff] [blame] | 351 | |
| 352 | return status; |
| 353 | } |
| 354 | |
| 355 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | * Attempt to establish a lock, and if it can't be granted, block it |
| 357 | * if required. |
| 358 | */ |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 359 | __be32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, |
| 361 | struct nlm_lock *lock, int wait, struct nlm_cookie *cookie) |
| 362 | { |
Marc Eshel | f812048 | 2006-12-05 23:48:10 -0500 | [diff] [blame] | 363 | struct nlm_block *block = NULL; |
Trond Myklebust | 255129d | 2007-09-25 15:55:03 -0400 | [diff] [blame] | 364 | struct nlm_host *host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | int error; |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 366 | __be32 ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | |
| 368 | dprintk("lockd: nlmsvc_lock(%s/%ld, ty=%d, pi=%d, %Ld-%Ld, bl=%d)\n", |
Josef Sipek | 225a719 | 2006-12-08 02:37:18 -0800 | [diff] [blame] | 369 | file->f_file->f_path.dentry->d_inode->i_sb->s_id, |
| 370 | file->f_file->f_path.dentry->d_inode->i_ino, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | lock->fl.fl_type, lock->fl.fl_pid, |
| 372 | (long long)lock->fl.fl_start, |
| 373 | (long long)lock->fl.fl_end, |
| 374 | wait); |
| 375 | |
Trond Myklebust | 255129d | 2007-09-25 15:55:03 -0400 | [diff] [blame] | 376 | /* Create host handle for callback */ |
| 377 | host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len); |
| 378 | if (host == NULL) |
| 379 | return nlm_lck_denied_nolocks; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | /* Lock file against concurrent access */ |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 382 | mutex_lock(&file->f_mutex); |
Marc Eshel | f812048 | 2006-12-05 23:48:10 -0500 | [diff] [blame] | 383 | /* Get existing block (in case client is busy-waiting) |
| 384 | * or create new block |
| 385 | */ |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 386 | block = nlmsvc_lookup_block(file, lock); |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 387 | if (block == NULL) { |
Trond Myklebust | 255129d | 2007-09-25 15:55:03 -0400 | [diff] [blame] | 388 | block = nlmsvc_create_block(rqstp, nlm_get_host(host), file, |
| 389 | lock, cookie); |
Marc Eshel | f812048 | 2006-12-05 23:48:10 -0500 | [diff] [blame] | 390 | ret = nlm_lck_denied_nolocks; |
| 391 | if (block == NULL) |
| 392 | goto out; |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 393 | lock = &block->b_call->a_args.lock; |
Marc Eshel | f812048 | 2006-12-05 23:48:10 -0500 | [diff] [blame] | 394 | } else |
| 395 | lock->fl.fl_flags &= ~FL_SLEEP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 397 | if (block->b_flags & B_QUEUED) { |
| 398 | dprintk("lockd: nlmsvc_lock deferred block %p flags %d\n", |
| 399 | block, block->b_flags); |
| 400 | if (block->b_granted) { |
| 401 | nlmsvc_unlink_block(block); |
| 402 | ret = nlm_granted; |
| 403 | goto out; |
| 404 | } |
| 405 | if (block->b_flags & B_TIMED_OUT) { |
| 406 | nlmsvc_unlink_block(block); |
| 407 | ret = nlm_lck_denied; |
| 408 | goto out; |
| 409 | } |
| 410 | ret = nlm_drop_reply; |
| 411 | goto out; |
| 412 | } |
| 413 | |
| 414 | if (!wait) |
| 415 | lock->fl.fl_flags &= ~FL_SLEEP; |
| 416 | error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 417 | lock->fl.fl_flags &= ~FL_SLEEP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 419 | dprintk("lockd: vfs_lock_file returned %d\n", error); |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 420 | switch(error) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | case 0: |
Andy Adamson | 15dadef | 2006-03-20 13:44:24 -0500 | [diff] [blame] | 422 | ret = nlm_granted; |
| 423 | goto out; |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 424 | case -EAGAIN: |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 425 | ret = nlm_lck_denied; |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 426 | break; |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 427 | case -EINPROGRESS: |
| 428 | if (wait) |
| 429 | break; |
| 430 | /* Filesystem lock operation is in progress |
| 431 | Add it to the queue waiting for callback */ |
| 432 | ret = nlmsvc_defer_lock_rqst(rqstp, block); |
| 433 | goto out; |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 434 | case -EDEADLK: |
Andy Adamson | 15dadef | 2006-03-20 13:44:24 -0500 | [diff] [blame] | 435 | ret = nlm_deadlock; |
| 436 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | default: /* includes ENOLCK */ |
Andy Adamson | 15dadef | 2006-03-20 13:44:24 -0500 | [diff] [blame] | 438 | ret = nlm_lck_denied_nolocks; |
| 439 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | } |
| 441 | |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 442 | ret = nlm_lck_denied; |
| 443 | if (!wait) |
| 444 | goto out; |
| 445 | |
| 446 | ret = nlm_lck_blocked; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | |
| 448 | /* Append to list of blocked */ |
Marc Eshel | f812048 | 2006-12-05 23:48:10 -0500 | [diff] [blame] | 449 | nlmsvc_insert_block(block, NLM_NEVER); |
Andy Adamson | 15dadef | 2006-03-20 13:44:24 -0500 | [diff] [blame] | 450 | out: |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 451 | mutex_unlock(&file->f_mutex); |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 452 | nlmsvc_release_block(block); |
Trond Myklebust | 255129d | 2007-09-25 15:55:03 -0400 | [diff] [blame] | 453 | nlm_release_host(host); |
Andy Adamson | 15dadef | 2006-03-20 13:44:24 -0500 | [diff] [blame] | 454 | dprintk("lockd: nlmsvc_lock returned %u\n", ret); |
| 455 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | } |
| 457 | |
| 458 | /* |
| 459 | * Test for presence of a conflicting lock. |
| 460 | */ |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 461 | __be32 |
Marc Eshel | 85f3f1b3 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 462 | nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file, |
| 463 | struct nlm_lock *lock, struct nlm_lock *conflock, |
| 464 | struct nlm_cookie *cookie) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | { |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 466 | struct nlm_block *block = NULL; |
| 467 | int error; |
| 468 | __be32 ret; |
| 469 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n", |
Josef Sipek | 225a719 | 2006-12-08 02:37:18 -0800 | [diff] [blame] | 471 | file->f_file->f_path.dentry->d_inode->i_sb->s_id, |
| 472 | file->f_file->f_path.dentry->d_inode->i_ino, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | lock->fl.fl_type, |
| 474 | (long long)lock->fl.fl_start, |
| 475 | (long long)lock->fl.fl_end); |
| 476 | |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 477 | /* Get existing block (in case client is busy-waiting) */ |
| 478 | block = nlmsvc_lookup_block(file, lock); |
| 479 | |
| 480 | if (block == NULL) { |
| 481 | struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL); |
Trond Myklebust | 255129d | 2007-09-25 15:55:03 -0400 | [diff] [blame] | 482 | struct nlm_host *host; |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 483 | |
| 484 | if (conf == NULL) |
| 485 | return nlm_granted; |
Trond Myklebust | 255129d | 2007-09-25 15:55:03 -0400 | [diff] [blame] | 486 | /* Create host handle for callback */ |
| 487 | host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len); |
Trond Myklebust | a6d8543 | 2007-10-09 11:04:57 -0400 | [diff] [blame] | 488 | if (host == NULL) { |
| 489 | kfree(conf); |
Trond Myklebust | 255129d | 2007-09-25 15:55:03 -0400 | [diff] [blame] | 490 | return nlm_lck_denied_nolocks; |
Trond Myklebust | a6d8543 | 2007-10-09 11:04:57 -0400 | [diff] [blame] | 491 | } |
Trond Myklebust | 255129d | 2007-09-25 15:55:03 -0400 | [diff] [blame] | 492 | block = nlmsvc_create_block(rqstp, host, file, lock, cookie); |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 493 | if (block == NULL) { |
| 494 | kfree(conf); |
| 495 | return nlm_granted; |
| 496 | } |
| 497 | block->b_fl = conf; |
| 498 | } |
| 499 | if (block->b_flags & B_QUEUED) { |
| 500 | dprintk("lockd: nlmsvc_testlock deferred block %p flags %d fl %p\n", |
| 501 | block, block->b_flags, block->b_fl); |
| 502 | if (block->b_flags & B_TIMED_OUT) { |
| 503 | nlmsvc_unlink_block(block); |
| 504 | return nlm_lck_denied; |
| 505 | } |
| 506 | if (block->b_flags & B_GOT_CALLBACK) { |
| 507 | if (block->b_fl != NULL |
| 508 | && block->b_fl->fl_type != F_UNLCK) { |
| 509 | lock->fl = *block->b_fl; |
| 510 | goto conf_lock; |
| 511 | } |
| 512 | else { |
| 513 | nlmsvc_unlink_block(block); |
| 514 | return nlm_granted; |
| 515 | } |
| 516 | } |
| 517 | return nlm_drop_reply; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | } |
| 519 | |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 520 | error = vfs_test_lock(file->f_file, &lock->fl); |
| 521 | if (error == -EINPROGRESS) |
| 522 | return nlmsvc_defer_lock_rqst(rqstp, block); |
| 523 | if (error) { |
| 524 | ret = nlm_lck_denied_nolocks; |
| 525 | goto out; |
| 526 | } |
| 527 | if (lock->fl.fl_type == F_UNLCK) { |
| 528 | ret = nlm_granted; |
| 529 | goto out; |
| 530 | } |
| 531 | |
| 532 | conf_lock: |
| 533 | dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n", |
| 534 | lock->fl.fl_type, (long long)lock->fl.fl_start, |
| 535 | (long long)lock->fl.fl_end); |
| 536 | conflock->caller = "somehost"; /* FIXME */ |
| 537 | conflock->len = strlen(conflock->caller); |
| 538 | conflock->oh.len = 0; /* don't return OH info */ |
| 539 | conflock->svid = lock->fl.fl_pid; |
| 540 | conflock->fl.fl_type = lock->fl.fl_type; |
| 541 | conflock->fl.fl_start = lock->fl.fl_start; |
| 542 | conflock->fl.fl_end = lock->fl.fl_end; |
| 543 | ret = nlm_lck_denied; |
| 544 | out: |
| 545 | if (block) |
| 546 | nlmsvc_release_block(block); |
| 547 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | } |
| 549 | |
| 550 | /* |
| 551 | * Remove a lock. |
| 552 | * This implies a CANCEL call: We send a GRANT_MSG, the client replies |
| 553 | * with a GRANT_RES call which gets lost, and calls UNLOCK immediately |
| 554 | * afterwards. In this case the block will still be there, and hence |
| 555 | * must be removed. |
| 556 | */ |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 557 | __be32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock) |
| 559 | { |
| 560 | int error; |
| 561 | |
| 562 | dprintk("lockd: nlmsvc_unlock(%s/%ld, pi=%d, %Ld-%Ld)\n", |
Josef Sipek | 225a719 | 2006-12-08 02:37:18 -0800 | [diff] [blame] | 563 | file->f_file->f_path.dentry->d_inode->i_sb->s_id, |
| 564 | file->f_file->f_path.dentry->d_inode->i_ino, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | lock->fl.fl_pid, |
| 566 | (long long)lock->fl.fl_start, |
| 567 | (long long)lock->fl.fl_end); |
| 568 | |
| 569 | /* First, cancel any lock that might be there */ |
| 570 | nlmsvc_cancel_blocked(file, lock); |
| 571 | |
| 572 | lock->fl.fl_type = F_UNLCK; |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 573 | error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | |
| 575 | return (error < 0)? nlm_lck_denied_nolocks : nlm_granted; |
| 576 | } |
| 577 | |
| 578 | /* |
| 579 | * Cancel a previously blocked request. |
| 580 | * |
| 581 | * A cancel request always overrides any grant that may currently |
| 582 | * be in progress. |
| 583 | * The calling procedure must check whether the file can be closed. |
| 584 | */ |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 585 | __be32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock) |
| 587 | { |
| 588 | struct nlm_block *block; |
J. Bruce Fields | 64a318e | 2006-01-03 09:55:46 +0100 | [diff] [blame] | 589 | int status = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | |
| 591 | dprintk("lockd: nlmsvc_cancel(%s/%ld, pi=%d, %Ld-%Ld)\n", |
Josef Sipek | 225a719 | 2006-12-08 02:37:18 -0800 | [diff] [blame] | 592 | file->f_file->f_path.dentry->d_inode->i_sb->s_id, |
| 593 | file->f_file->f_path.dentry->d_inode->i_ino, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | lock->fl.fl_pid, |
| 595 | (long long)lock->fl.fl_start, |
| 596 | (long long)lock->fl.fl_end); |
| 597 | |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 598 | mutex_lock(&file->f_mutex); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 599 | block = nlmsvc_lookup_block(file, lock); |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 600 | mutex_unlock(&file->f_mutex); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 601 | if (block != NULL) { |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 602 | vfs_cancel_lock(block->b_file->f_file, |
| 603 | &block->b_call->a_args.lock.fl); |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 604 | status = nlmsvc_unlink_block(block); |
| 605 | nlmsvc_release_block(block); |
| 606 | } |
J. Bruce Fields | 64a318e | 2006-01-03 09:55:46 +0100 | [diff] [blame] | 607 | return status ? nlm_lck_denied : nlm_granted; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | } |
| 609 | |
| 610 | /* |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 611 | * This is a callback from the filesystem for VFS file lock requests. |
| 612 | * It will be used if fl_grant is defined and the filesystem can not |
| 613 | * respond to the request immediately. |
| 614 | * For GETLK request it will copy the reply to the nlm_block. |
| 615 | * For SETLK or SETLKW request it will get the local posix lock. |
| 616 | * In all cases it will move the block to the head of nlm_blocked q where |
| 617 | * nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the |
| 618 | * deferred rpc for GETLK and SETLK. |
| 619 | */ |
| 620 | static void |
| 621 | nlmsvc_update_deferred_block(struct nlm_block *block, struct file_lock *conf, |
| 622 | int result) |
| 623 | { |
| 624 | block->b_flags |= B_GOT_CALLBACK; |
| 625 | if (result == 0) |
| 626 | block->b_granted = 1; |
| 627 | else |
| 628 | block->b_flags |= B_TIMED_OUT; |
| 629 | if (conf) { |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 630 | if (block->b_fl) |
| 631 | locks_copy_lock(block->b_fl, conf); |
| 632 | } |
| 633 | } |
| 634 | |
| 635 | static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf, |
| 636 | int result) |
| 637 | { |
| 638 | struct nlm_block *block; |
| 639 | int rc = -ENOENT; |
| 640 | |
| 641 | lock_kernel(); |
| 642 | list_for_each_entry(block, &nlm_blocked, b_list) { |
| 643 | if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) { |
| 644 | dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n", |
| 645 | block, block->b_flags); |
| 646 | if (block->b_flags & B_QUEUED) { |
| 647 | if (block->b_flags & B_TIMED_OUT) { |
| 648 | rc = -ENOLCK; |
| 649 | break; |
| 650 | } |
| 651 | nlmsvc_update_deferred_block(block, conf, result); |
| 652 | } else if (result == 0) |
| 653 | block->b_granted = 1; |
| 654 | |
| 655 | nlmsvc_insert_block(block, 0); |
| 656 | svc_wake_up(block->b_daemon); |
| 657 | rc = 0; |
| 658 | break; |
| 659 | } |
| 660 | } |
| 661 | unlock_kernel(); |
| 662 | if (rc == -ENOENT) |
| 663 | printk(KERN_WARNING "lockd: grant for unknown block\n"); |
| 664 | return rc; |
| 665 | } |
| 666 | |
| 667 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 668 | * Unblock a blocked lock request. This is a callback invoked from the |
| 669 | * VFS layer when a lock on which we blocked is removed. |
| 670 | * |
| 671 | * This function doesn't grant the blocked lock instantly, but rather moves |
| 672 | * the block to the head of nlm_blocked where it can be picked up by lockd. |
| 673 | */ |
| 674 | static void |
| 675 | nlmsvc_notify_blocked(struct file_lock *fl) |
| 676 | { |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 677 | struct nlm_block *block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 678 | |
| 679 | dprintk("lockd: VFS unblock notification for block %p\n", fl); |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 680 | list_for_each_entry(block, &nlm_blocked, b_list) { |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 681 | if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | nlmsvc_insert_block(block, 0); |
| 683 | svc_wake_up(block->b_daemon); |
| 684 | return; |
| 685 | } |
| 686 | } |
| 687 | |
| 688 | printk(KERN_WARNING "lockd: notification for unknown block!\n"); |
| 689 | } |
| 690 | |
| 691 | static int nlmsvc_same_owner(struct file_lock *fl1, struct file_lock *fl2) |
| 692 | { |
| 693 | return fl1->fl_owner == fl2->fl_owner && fl1->fl_pid == fl2->fl_pid; |
| 694 | } |
| 695 | |
| 696 | struct lock_manager_operations nlmsvc_lock_operations = { |
| 697 | .fl_compare_owner = nlmsvc_same_owner, |
| 698 | .fl_notify = nlmsvc_notify_blocked, |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 699 | .fl_grant = nlmsvc_grant_deferred, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | }; |
| 701 | |
| 702 | /* |
| 703 | * Try to claim a lock that was previously blocked. |
| 704 | * |
| 705 | * Note that we use both the RPC_GRANTED_MSG call _and_ an async |
| 706 | * RPC thread when notifying the client. This seems like overkill... |
| 707 | * Here's why: |
| 708 | * - we don't want to use a synchronous RPC thread, otherwise |
| 709 | * we might find ourselves hanging on a dead portmapper. |
| 710 | * - Some lockd implementations (e.g. HP) don't react to |
| 711 | * RPC_GRANTED calls; they seem to insist on RPC_GRANTED_MSG calls. |
| 712 | */ |
| 713 | static void |
| 714 | nlmsvc_grant_blocked(struct nlm_block *block) |
| 715 | { |
| 716 | struct nlm_file *file = block->b_file; |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 717 | struct nlm_lock *lock = &block->b_call->a_args.lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 718 | int error; |
| 719 | |
| 720 | dprintk("lockd: grant blocked lock %p\n", block); |
| 721 | |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 722 | kref_get(&block->b_count); |
| 723 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | /* Unlink block request from list */ |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 725 | nlmsvc_unlink_block(block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | |
| 727 | /* If b_granted is true this means we've been here before. |
| 728 | * Just retry the grant callback, possibly refreshing the RPC |
| 729 | * binding */ |
| 730 | if (block->b_granted) { |
| 731 | nlm_rebind_host(block->b_host); |
| 732 | goto callback; |
| 733 | } |
| 734 | |
| 735 | /* Try the lock operation again */ |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 736 | lock->fl.fl_flags |= FL_SLEEP; |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 737 | error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 738 | lock->fl.fl_flags &= ~FL_SLEEP; |
| 739 | |
Andy Adamson | 5de0e50 | 2006-03-20 13:44:25 -0500 | [diff] [blame] | 740 | switch (error) { |
| 741 | case 0: |
| 742 | break; |
| 743 | case -EAGAIN: |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 744 | case -EINPROGRESS: |
| 745 | dprintk("lockd: lock still blocked error %d\n", error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | nlmsvc_insert_block(block, NLM_NEVER); |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 747 | nlmsvc_release_block(block); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 748 | return; |
Andy Adamson | 5de0e50 | 2006-03-20 13:44:25 -0500 | [diff] [blame] | 749 | default: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 750 | printk(KERN_WARNING "lockd: unexpected error %d in %s!\n", |
| 751 | -error, __FUNCTION__); |
| 752 | nlmsvc_insert_block(block, 10 * HZ); |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 753 | nlmsvc_release_block(block); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 754 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | } |
| 756 | |
| 757 | callback: |
| 758 | /* Lock was granted by VFS. */ |
| 759 | dprintk("lockd: GRANTing blocked lock.\n"); |
| 760 | block->b_granted = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | |
| 762 | /* Schedule next grant callback in 30 seconds */ |
| 763 | nlmsvc_insert_block(block, 30 * HZ); |
| 764 | |
| 765 | /* Call the client */ |
Trond Myklebust | a995e9e | 2007-02-02 15:37:43 -0800 | [diff] [blame] | 766 | nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG, &nlmsvc_grant_ops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | } |
| 768 | |
| 769 | /* |
| 770 | * This is the callback from the RPC layer when the NLM_GRANTED_MSG |
| 771 | * RPC call has succeeded or timed out. |
| 772 | * Like all RPC callbacks, it is invoked by the rpciod process, so it |
| 773 | * better not sleep. Therefore, we put the blocked lock on the nlm_blocked |
| 774 | * chain once more in order to have it removed by lockd itself (which can |
| 775 | * then sleep on the file semaphore without disrupting e.g. the nfs client). |
| 776 | */ |
Trond Myklebust | 963d8fe | 2006-01-03 09:55:04 +0100 | [diff] [blame] | 777 | static void nlmsvc_grant_callback(struct rpc_task *task, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | { |
Trond Myklebust | 963d8fe | 2006-01-03 09:55:04 +0100 | [diff] [blame] | 779 | struct nlm_rqst *call = data; |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 780 | struct nlm_block *block = call->a_block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | unsigned long timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | |
| 783 | dprintk("lockd: GRANT_MSG RPC callback\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 784 | |
| 785 | /* Technically, we should down the file semaphore here. Since we |
| 786 | * move the block towards the head of the queue only, no harm |
| 787 | * can be done, though. */ |
| 788 | if (task->tk_status < 0) { |
| 789 | /* RPC error: Re-insert for retransmission */ |
| 790 | timeout = 10 * HZ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | } else { |
| 792 | /* Call was successful, now wait for client callback */ |
| 793 | timeout = 60 * HZ; |
| 794 | } |
| 795 | nlmsvc_insert_block(block, timeout); |
| 796 | svc_wake_up(block->b_daemon); |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 797 | } |
| 798 | |
Adrian Bunk | ec535ce | 2006-04-18 13:21:50 -0400 | [diff] [blame] | 799 | static void nlmsvc_grant_release(void *data) |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 800 | { |
Trond Myklebust | 6041b79 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 801 | struct nlm_rqst *call = data; |
| 802 | |
| 803 | nlmsvc_release_block(call->a_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 804 | } |
| 805 | |
Trond Myklebust | 963d8fe | 2006-01-03 09:55:04 +0100 | [diff] [blame] | 806 | static const struct rpc_call_ops nlmsvc_grant_ops = { |
| 807 | .rpc_call_done = nlmsvc_grant_callback, |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 808 | .rpc_release = nlmsvc_grant_release, |
Trond Myklebust | 963d8fe | 2006-01-03 09:55:04 +0100 | [diff] [blame] | 809 | }; |
| 810 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 811 | /* |
| 812 | * We received a GRANT_RES callback. Try to find the corresponding |
| 813 | * block. |
| 814 | */ |
| 815 | void |
Al Viro | e8c5c04 | 2006-12-13 00:35:03 -0800 | [diff] [blame] | 816 | nlmsvc_grant_reply(struct nlm_cookie *cookie, __be32 status) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 817 | { |
| 818 | struct nlm_block *block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | |
Olaf Kirch | 39be450 | 2006-10-04 02:16:03 -0700 | [diff] [blame] | 820 | dprintk("grant_reply: looking for cookie %x, s=%d \n", |
| 821 | *(unsigned int *)(cookie->data), status); |
| 822 | if (!(block = nlmsvc_find_block(cookie))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 823 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 824 | |
J. Bruce Fields | f232142 | 2006-01-03 09:55:42 +0100 | [diff] [blame] | 825 | if (block) { |
Al Viro | e8c5c04 | 2006-12-13 00:35:03 -0800 | [diff] [blame] | 826 | if (status == nlm_lck_denied_grace_period) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | /* Try again in a couple of seconds */ |
| 828 | nlmsvc_insert_block(block, 10 * HZ); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | } else { |
| 830 | /* Lock is now held by client, or has been rejected. |
| 831 | * In both cases, the block should be removed. */ |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 832 | nlmsvc_unlink_block(block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | } |
| 834 | } |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 835 | nlmsvc_release_block(block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 836 | } |
| 837 | |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 838 | /* Helper function to handle retry of a deferred block. |
| 839 | * If it is a blocking lock, call grant_blocked. |
| 840 | * For a non-blocking lock or test lock, revisit the request. |
| 841 | */ |
| 842 | static void |
| 843 | retry_deferred_block(struct nlm_block *block) |
| 844 | { |
| 845 | if (!(block->b_flags & B_GOT_CALLBACK)) |
| 846 | block->b_flags |= B_TIMED_OUT; |
| 847 | nlmsvc_insert_block(block, NLM_TIMEOUT); |
| 848 | dprintk("revisit block %p flags %d\n", block, block->b_flags); |
| 849 | if (block->b_deferred_req) { |
| 850 | block->b_deferred_req->revisit(block->b_deferred_req, 0); |
| 851 | block->b_deferred_req = NULL; |
| 852 | } |
| 853 | } |
| 854 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 855 | /* |
| 856 | * Retry all blocked locks that have been notified. This is where lockd |
| 857 | * picks up locks that can be granted, or grant notifications that must |
| 858 | * be retransmitted. |
| 859 | */ |
| 860 | unsigned long |
| 861 | nlmsvc_retry_blocked(void) |
| 862 | { |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 863 | unsigned long timeout = MAX_SCHEDULE_TIMEOUT; |
| 864 | struct nlm_block *block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 865 | |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 866 | while (!list_empty(&nlm_blocked)) { |
| 867 | block = list_entry(nlm_blocked.next, struct nlm_block, b_list); |
| 868 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 869 | if (block->b_when == NLM_NEVER) |
| 870 | break; |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 871 | if (time_after(block->b_when,jiffies)) { |
| 872 | timeout = block->b_when - jiffies; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 873 | break; |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 874 | } |
| 875 | |
J. Bruce Fields | f3d43c7 | 2006-08-03 15:07:47 -0400 | [diff] [blame] | 876 | dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n", |
| 877 | block, block->b_when); |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 878 | if (block->b_flags & B_QUEUED) { |
| 879 | dprintk("nlmsvc_retry_blocked delete block (%p, granted=%d, flags=%d)\n", |
| 880 | block, block->b_granted, block->b_flags); |
| 881 | retry_deferred_block(block); |
| 882 | } else |
| 883 | nlmsvc_grant_blocked(block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | } |
| 885 | |
Olaf Kirch | 68a2d76 | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 886 | return timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 887 | } |