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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | 68a2d76c | 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 | */ |
| 174 | static inline struct nlm_block * |
| 175 | nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file, |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 176 | struct nlm_lock *lock, struct nlm_cookie *cookie) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | { |
| 178 | struct nlm_block *block; |
| 179 | struct nlm_host *host; |
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 | |
| 182 | /* Create host handle for callback */ |
Olaf Kirch | db4e4c9 | 2006-10-04 02:15:52 -0700 | [diff] [blame] | 183 | host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | if (host == NULL) |
| 185 | return NULL; |
| 186 | |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 187 | call = nlm_alloc_call(host); |
| 188 | if (call == NULL) |
| 189 | return NULL; |
| 190 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | /* Allocate memory for block, and initialize arguments */ |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 192 | block = kzalloc(sizeof(*block), GFP_KERNEL); |
| 193 | if (block == NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | goto failed; |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 195 | kref_init(&block->b_count); |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 196 | INIT_LIST_HEAD(&block->b_list); |
| 197 | INIT_LIST_HEAD(&block->b_flist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 199 | if (!nlmsvc_setgrantargs(call, lock)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | goto failed_free; |
| 201 | |
| 202 | /* Set notifier function for VFS, and init args */ |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 203 | call->a_args.lock.fl.fl_flags |= FL_SLEEP; |
| 204 | call->a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations; |
Olaf Kirch | 39be450 | 2006-10-04 02:16:03 -0700 | [diff] [blame] | 205 | nlmclnt_next_cookie(&call->a_args.cookie); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | |
| 207 | dprintk("lockd: created block %p...\n", block); |
| 208 | |
| 209 | /* Create and initialize the block */ |
| 210 | block->b_daemon = rqstp->rq_server; |
| 211 | block->b_host = host; |
| 212 | block->b_file = file; |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 213 | block->b_fl = NULL; |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 214 | file->f_count++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | |
| 216 | /* Add to file's list of blocks */ |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 217 | list_add(&block->b_flist, &file->f_blocks); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | |
| 219 | /* Set up RPC arguments for callback */ |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 220 | block->b_call = call; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | call->a_flags = RPC_TASK_ASYNC; |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 222 | call->a_block = block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | |
| 224 | return block; |
| 225 | |
| 226 | failed_free: |
| 227 | kfree(block); |
| 228 | failed: |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 229 | nlm_release_call(call); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | return NULL; |
| 231 | } |
| 232 | |
| 233 | /* |
| 234 | * Delete a block. If the lock was cancelled or the grant callback |
| 235 | * failed, unlock is set to 1. |
| 236 | * It is the caller's responsibility to check whether the file |
| 237 | * can be closed hereafter. |
| 238 | */ |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 239 | static int nlmsvc_unlink_block(struct nlm_block *block) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | { |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 241 | int status; |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 242 | dprintk("lockd: unlinking block %p...\n", block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | |
| 244 | /* Remove block from list */ |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 245 | 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] | 246 | nlmsvc_remove_block(block); |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 247 | return status; |
| 248 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 250 | static void nlmsvc_free_block(struct kref *kref) |
| 251 | { |
| 252 | struct nlm_block *block = container_of(kref, struct nlm_block, b_count); |
| 253 | struct nlm_file *file = block->b_file; |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 254 | |
| 255 | dprintk("lockd: freeing block %p...\n", block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | |
| 257 | /* Remove block from file's list of blocks */ |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 258 | mutex_lock(&file->f_mutex); |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 259 | list_del_init(&block->b_flist); |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 260 | mutex_unlock(&file->f_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 262 | nlmsvc_freegrantargs(block->b_call); |
| 263 | nlm_release_call(block->b_call); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 264 | nlm_release_file(block->b_file); |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 265 | kfree(block->b_fl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | kfree(block); |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 267 | } |
| 268 | |
| 269 | static void nlmsvc_release_block(struct nlm_block *block) |
| 270 | { |
| 271 | if (block != NULL) |
| 272 | kref_put(&block->b_count, nlmsvc_free_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | } |
| 274 | |
Olaf Kirch | f2af793 | 2006-10-04 02:15:59 -0700 | [diff] [blame] | 275 | /* |
| 276 | * Loop over all blocks and delete blocks held by |
| 277 | * a matching host. |
| 278 | */ |
| 279 | void nlmsvc_traverse_blocks(struct nlm_host *host, |
| 280 | struct nlm_file *file, |
| 281 | nlm_host_match_fn_t match) |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 282 | { |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 283 | struct nlm_block *block, *next; |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 284 | |
| 285 | restart: |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 286 | mutex_lock(&file->f_mutex); |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 287 | list_for_each_entry_safe(block, next, &file->f_blocks, b_flist) { |
Olaf Kirch | f2af793 | 2006-10-04 02:15:59 -0700 | [diff] [blame] | 288 | if (!match(block->b_host, host)) |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 289 | continue; |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 290 | /* Do not destroy blocks that are not on |
| 291 | * the global retry list - why? */ |
| 292 | if (list_empty(&block->b_list)) |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 293 | continue; |
| 294 | kref_get(&block->b_count); |
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 | nlmsvc_unlink_block(block); |
| 297 | nlmsvc_release_block(block); |
| 298 | goto restart; |
| 299 | } |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 300 | mutex_unlock(&file->f_mutex); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 301 | } |
| 302 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | /* |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 304 | * Initialize arguments for GRANTED call. The nlm_rqst structure |
| 305 | * has been cleared already. |
| 306 | */ |
| 307 | static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock) |
| 308 | { |
| 309 | locks_copy_lock(&call->a_args.lock.fl, &lock->fl); |
| 310 | 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] | 311 | call->a_args.lock.caller = utsname()->nodename; |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 312 | call->a_args.lock.oh.len = lock->oh.len; |
| 313 | |
| 314 | /* set default data area */ |
| 315 | call->a_args.lock.oh.data = call->a_owner; |
| 316 | call->a_args.lock.svid = lock->fl.fl_pid; |
| 317 | |
| 318 | if (lock->oh.len > NLMCLNT_OHSIZE) { |
| 319 | void *data = kmalloc(lock->oh.len, GFP_KERNEL); |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 320 | if (!data) |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 321 | return 0; |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 322 | call->a_args.lock.oh.data = (u8 *) data; |
| 323 | } |
| 324 | |
| 325 | memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len); |
| 326 | return 1; |
| 327 | } |
| 328 | |
| 329 | static void nlmsvc_freegrantargs(struct nlm_rqst *call) |
| 330 | { |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 331 | if (call->a_args.lock.oh.data != call->a_owner) |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 332 | kfree(call->a_args.lock.oh.data); |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 333 | } |
| 334 | |
| 335 | /* |
Marc Eshel | 2b36f41 | 2006-11-28 16:26:47 -0500 | [diff] [blame] | 336 | * Deferred lock request handling for non-blocking lock |
| 337 | */ |
| 338 | static u32 |
| 339 | nlmsvc_defer_lock_rqst(struct svc_rqst *rqstp, struct nlm_block *block) |
| 340 | { |
| 341 | u32 status = nlm_lck_denied_nolocks; |
| 342 | |
| 343 | block->b_flags |= B_QUEUED; |
| 344 | |
| 345 | nlmsvc_insert_block(block, NLM_TIMEOUT); |
| 346 | |
| 347 | block->b_cache_req = &rqstp->rq_chandle; |
| 348 | if (rqstp->rq_chandle.defer) { |
| 349 | block->b_deferred_req = |
| 350 | rqstp->rq_chandle.defer(block->b_cache_req); |
| 351 | if (block->b_deferred_req != NULL) |
| 352 | status = nlm_drop_reply; |
| 353 | } |
| 354 | dprintk("lockd: nlmsvc_defer_lock_rqst block %p flags %d status %d\n", |
| 355 | block, block->b_flags, status); |
| 356 | |
| 357 | return status; |
| 358 | } |
| 359 | |
| 360 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | * Attempt to establish a lock, and if it can't be granted, block it |
| 362 | * if required. |
| 363 | */ |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 364 | __be32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, |
| 366 | struct nlm_lock *lock, int wait, struct nlm_cookie *cookie) |
| 367 | { |
Marc Eshel | f812048 | 2006-12-05 23:48:10 -0500 | [diff] [blame] | 368 | struct nlm_block *block = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | int error; |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 370 | __be32 ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | |
| 372 | 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] | 373 | file->f_file->f_path.dentry->d_inode->i_sb->s_id, |
| 374 | file->f_file->f_path.dentry->d_inode->i_ino, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | lock->fl.fl_type, lock->fl.fl_pid, |
| 376 | (long long)lock->fl.fl_start, |
| 377 | (long long)lock->fl.fl_end, |
| 378 | wait); |
| 379 | |
| 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) { |
Marc Eshel | f812048 | 2006-12-05 23:48:10 -0500 | [diff] [blame] | 388 | block = nlmsvc_create_block(rqstp, file, lock, cookie); |
| 389 | ret = nlm_lck_denied_nolocks; |
| 390 | if (block == NULL) |
| 391 | goto out; |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 392 | lock = &block->b_call->a_args.lock; |
Marc Eshel | f812048 | 2006-12-05 23:48:10 -0500 | [diff] [blame] | 393 | } else |
| 394 | lock->fl.fl_flags &= ~FL_SLEEP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 396 | if (block->b_flags & B_QUEUED) { |
| 397 | dprintk("lockd: nlmsvc_lock deferred block %p flags %d\n", |
| 398 | block, block->b_flags); |
| 399 | if (block->b_granted) { |
| 400 | nlmsvc_unlink_block(block); |
| 401 | ret = nlm_granted; |
| 402 | goto out; |
| 403 | } |
| 404 | if (block->b_flags & B_TIMED_OUT) { |
| 405 | nlmsvc_unlink_block(block); |
| 406 | ret = nlm_lck_denied; |
| 407 | goto out; |
| 408 | } |
| 409 | ret = nlm_drop_reply; |
| 410 | goto out; |
| 411 | } |
| 412 | |
| 413 | if (!wait) |
| 414 | lock->fl.fl_flags &= ~FL_SLEEP; |
| 415 | error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 416 | lock->fl.fl_flags &= ~FL_SLEEP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 418 | dprintk("lockd: vfs_lock_file returned %d\n", error); |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 419 | switch(error) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | case 0: |
Andy Adamson | 15dadef | 2006-03-20 13:44:24 -0500 | [diff] [blame] | 421 | ret = nlm_granted; |
| 422 | goto out; |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 423 | case -EAGAIN: |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 424 | ret = nlm_lck_denied; |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 425 | break; |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 426 | case -EINPROGRESS: |
| 427 | if (wait) |
| 428 | break; |
| 429 | /* Filesystem lock operation is in progress |
| 430 | Add it to the queue waiting for callback */ |
| 431 | ret = nlmsvc_defer_lock_rqst(rqstp, block); |
| 432 | goto out; |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 433 | case -EDEADLK: |
Andy Adamson | 15dadef | 2006-03-20 13:44:24 -0500 | [diff] [blame] | 434 | ret = nlm_deadlock; |
| 435 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | default: /* includes ENOLCK */ |
Andy Adamson | 15dadef | 2006-03-20 13:44:24 -0500 | [diff] [blame] | 437 | ret = nlm_lck_denied_nolocks; |
| 438 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | } |
| 440 | |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 441 | ret = nlm_lck_denied; |
| 442 | if (!wait) |
| 443 | goto out; |
| 444 | |
| 445 | ret = nlm_lck_blocked; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | |
| 447 | /* Append to list of blocked */ |
Marc Eshel | f812048 | 2006-12-05 23:48:10 -0500 | [diff] [blame] | 448 | nlmsvc_insert_block(block, NLM_NEVER); |
Andy Adamson | 15dadef | 2006-03-20 13:44:24 -0500 | [diff] [blame] | 449 | out: |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 450 | mutex_unlock(&file->f_mutex); |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 451 | nlmsvc_release_block(block); |
Andy Adamson | 15dadef | 2006-03-20 13:44:24 -0500 | [diff] [blame] | 452 | dprintk("lockd: nlmsvc_lock returned %u\n", ret); |
| 453 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | } |
| 455 | |
| 456 | /* |
| 457 | * Test for presence of a conflicting lock. |
| 458 | */ |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 459 | __be32 |
Marc Eshel | 85f3f1b3 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 460 | nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file, |
| 461 | struct nlm_lock *lock, struct nlm_lock *conflock, |
| 462 | struct nlm_cookie *cookie) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | { |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 464 | struct nlm_block *block = NULL; |
| 465 | int error; |
| 466 | __be32 ret; |
| 467 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n", |
Josef Sipek | 225a719 | 2006-12-08 02:37:18 -0800 | [diff] [blame] | 469 | file->f_file->f_path.dentry->d_inode->i_sb->s_id, |
| 470 | file->f_file->f_path.dentry->d_inode->i_ino, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | lock->fl.fl_type, |
| 472 | (long long)lock->fl.fl_start, |
| 473 | (long long)lock->fl.fl_end); |
| 474 | |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 475 | /* Get existing block (in case client is busy-waiting) */ |
| 476 | block = nlmsvc_lookup_block(file, lock); |
| 477 | |
| 478 | if (block == NULL) { |
| 479 | struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL); |
| 480 | |
| 481 | if (conf == NULL) |
| 482 | return nlm_granted; |
| 483 | block = nlmsvc_create_block(rqstp, file, lock, cookie); |
| 484 | if (block == NULL) { |
| 485 | kfree(conf); |
| 486 | return nlm_granted; |
| 487 | } |
| 488 | block->b_fl = conf; |
| 489 | } |
| 490 | if (block->b_flags & B_QUEUED) { |
| 491 | dprintk("lockd: nlmsvc_testlock deferred block %p flags %d fl %p\n", |
| 492 | block, block->b_flags, block->b_fl); |
| 493 | if (block->b_flags & B_TIMED_OUT) { |
| 494 | nlmsvc_unlink_block(block); |
| 495 | return nlm_lck_denied; |
| 496 | } |
| 497 | if (block->b_flags & B_GOT_CALLBACK) { |
| 498 | if (block->b_fl != NULL |
| 499 | && block->b_fl->fl_type != F_UNLCK) { |
| 500 | lock->fl = *block->b_fl; |
| 501 | goto conf_lock; |
| 502 | } |
| 503 | else { |
| 504 | nlmsvc_unlink_block(block); |
| 505 | return nlm_granted; |
| 506 | } |
| 507 | } |
| 508 | return nlm_drop_reply; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | } |
| 510 | |
Marc Eshel | 5ea0d75 | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 511 | error = vfs_test_lock(file->f_file, &lock->fl); |
| 512 | if (error == -EINPROGRESS) |
| 513 | return nlmsvc_defer_lock_rqst(rqstp, block); |
| 514 | if (error) { |
| 515 | ret = nlm_lck_denied_nolocks; |
| 516 | goto out; |
| 517 | } |
| 518 | if (lock->fl.fl_type == F_UNLCK) { |
| 519 | ret = nlm_granted; |
| 520 | goto out; |
| 521 | } |
| 522 | |
| 523 | conf_lock: |
| 524 | dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n", |
| 525 | lock->fl.fl_type, (long long)lock->fl.fl_start, |
| 526 | (long long)lock->fl.fl_end); |
| 527 | conflock->caller = "somehost"; /* FIXME */ |
| 528 | conflock->len = strlen(conflock->caller); |
| 529 | conflock->oh.len = 0; /* don't return OH info */ |
| 530 | conflock->svid = lock->fl.fl_pid; |
| 531 | conflock->fl.fl_type = lock->fl.fl_type; |
| 532 | conflock->fl.fl_start = lock->fl.fl_start; |
| 533 | conflock->fl.fl_end = lock->fl.fl_end; |
| 534 | ret = nlm_lck_denied; |
| 535 | out: |
| 536 | if (block) |
| 537 | nlmsvc_release_block(block); |
| 538 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | } |
| 540 | |
| 541 | /* |
| 542 | * Remove a lock. |
| 543 | * This implies a CANCEL call: We send a GRANT_MSG, the client replies |
| 544 | * with a GRANT_RES call which gets lost, and calls UNLOCK immediately |
| 545 | * afterwards. In this case the block will still be there, and hence |
| 546 | * must be removed. |
| 547 | */ |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 548 | __be32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock) |
| 550 | { |
| 551 | int error; |
| 552 | |
| 553 | dprintk("lockd: nlmsvc_unlock(%s/%ld, pi=%d, %Ld-%Ld)\n", |
Josef Sipek | 225a719 | 2006-12-08 02:37:18 -0800 | [diff] [blame] | 554 | file->f_file->f_path.dentry->d_inode->i_sb->s_id, |
| 555 | file->f_file->f_path.dentry->d_inode->i_ino, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | lock->fl.fl_pid, |
| 557 | (long long)lock->fl.fl_start, |
| 558 | (long long)lock->fl.fl_end); |
| 559 | |
| 560 | /* First, cancel any lock that might be there */ |
| 561 | nlmsvc_cancel_blocked(file, lock); |
| 562 | |
| 563 | lock->fl.fl_type = F_UNLCK; |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 564 | error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | |
| 566 | return (error < 0)? nlm_lck_denied_nolocks : nlm_granted; |
| 567 | } |
| 568 | |
| 569 | /* |
| 570 | * Cancel a previously blocked request. |
| 571 | * |
| 572 | * A cancel request always overrides any grant that may currently |
| 573 | * be in progress. |
| 574 | * The calling procedure must check whether the file can be closed. |
| 575 | */ |
Al Viro | 52921e0 | 2006-10-19 23:28:46 -0700 | [diff] [blame] | 576 | __be32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock) |
| 578 | { |
| 579 | struct nlm_block *block; |
J. Bruce Fields | 64a318e | 2006-01-03 09:55:46 +0100 | [diff] [blame] | 580 | int status = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | |
| 582 | dprintk("lockd: nlmsvc_cancel(%s/%ld, pi=%d, %Ld-%Ld)\n", |
Josef Sipek | 225a719 | 2006-12-08 02:37:18 -0800 | [diff] [blame] | 583 | file->f_file->f_path.dentry->d_inode->i_sb->s_id, |
| 584 | file->f_file->f_path.dentry->d_inode->i_ino, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | lock->fl.fl_pid, |
| 586 | (long long)lock->fl.fl_start, |
| 587 | (long long)lock->fl.fl_end); |
| 588 | |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 589 | mutex_lock(&file->f_mutex); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 590 | block = nlmsvc_lookup_block(file, lock); |
Neil Brown | 89e63ef | 2006-10-04 02:16:06 -0700 | [diff] [blame] | 591 | mutex_unlock(&file->f_mutex); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 592 | if (block != NULL) { |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 593 | vfs_cancel_lock(block->b_file->f_file, |
| 594 | &block->b_call->a_args.lock.fl); |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 595 | status = nlmsvc_unlink_block(block); |
| 596 | nlmsvc_release_block(block); |
| 597 | } |
J. Bruce Fields | 64a318e | 2006-01-03 09:55:46 +0100 | [diff] [blame] | 598 | return status ? nlm_lck_denied : nlm_granted; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | } |
| 600 | |
| 601 | /* |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 602 | * This is a callback from the filesystem for VFS file lock requests. |
| 603 | * It will be used if fl_grant is defined and the filesystem can not |
| 604 | * respond to the request immediately. |
| 605 | * For GETLK request it will copy the reply to the nlm_block. |
| 606 | * For SETLK or SETLKW request it will get the local posix lock. |
| 607 | * In all cases it will move the block to the head of nlm_blocked q where |
| 608 | * nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the |
| 609 | * deferred rpc for GETLK and SETLK. |
| 610 | */ |
| 611 | static void |
| 612 | nlmsvc_update_deferred_block(struct nlm_block *block, struct file_lock *conf, |
| 613 | int result) |
| 614 | { |
| 615 | block->b_flags |= B_GOT_CALLBACK; |
| 616 | if (result == 0) |
| 617 | block->b_granted = 1; |
| 618 | else |
| 619 | block->b_flags |= B_TIMED_OUT; |
| 620 | if (conf) { |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 621 | if (block->b_fl) |
| 622 | locks_copy_lock(block->b_fl, conf); |
| 623 | } |
| 624 | } |
| 625 | |
| 626 | static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf, |
| 627 | int result) |
| 628 | { |
| 629 | struct nlm_block *block; |
| 630 | int rc = -ENOENT; |
| 631 | |
| 632 | lock_kernel(); |
| 633 | list_for_each_entry(block, &nlm_blocked, b_list) { |
| 634 | if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) { |
| 635 | dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n", |
| 636 | block, block->b_flags); |
| 637 | if (block->b_flags & B_QUEUED) { |
| 638 | if (block->b_flags & B_TIMED_OUT) { |
| 639 | rc = -ENOLCK; |
| 640 | break; |
| 641 | } |
| 642 | nlmsvc_update_deferred_block(block, conf, result); |
| 643 | } else if (result == 0) |
| 644 | block->b_granted = 1; |
| 645 | |
| 646 | nlmsvc_insert_block(block, 0); |
| 647 | svc_wake_up(block->b_daemon); |
| 648 | rc = 0; |
| 649 | break; |
| 650 | } |
| 651 | } |
| 652 | unlock_kernel(); |
| 653 | if (rc == -ENOENT) |
| 654 | printk(KERN_WARNING "lockd: grant for unknown block\n"); |
| 655 | return rc; |
| 656 | } |
| 657 | |
| 658 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 659 | * Unblock a blocked lock request. This is a callback invoked from the |
| 660 | * VFS layer when a lock on which we blocked is removed. |
| 661 | * |
| 662 | * This function doesn't grant the blocked lock instantly, but rather moves |
| 663 | * the block to the head of nlm_blocked where it can be picked up by lockd. |
| 664 | */ |
| 665 | static void |
| 666 | nlmsvc_notify_blocked(struct file_lock *fl) |
| 667 | { |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 668 | struct nlm_block *block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | |
| 670 | dprintk("lockd: VFS unblock notification for block %p\n", fl); |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 671 | list_for_each_entry(block, &nlm_blocked, b_list) { |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 672 | if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | nlmsvc_insert_block(block, 0); |
| 674 | svc_wake_up(block->b_daemon); |
| 675 | return; |
| 676 | } |
| 677 | } |
| 678 | |
| 679 | printk(KERN_WARNING "lockd: notification for unknown block!\n"); |
| 680 | } |
| 681 | |
| 682 | static int nlmsvc_same_owner(struct file_lock *fl1, struct file_lock *fl2) |
| 683 | { |
| 684 | return fl1->fl_owner == fl2->fl_owner && fl1->fl_pid == fl2->fl_pid; |
| 685 | } |
| 686 | |
| 687 | struct lock_manager_operations nlmsvc_lock_operations = { |
| 688 | .fl_compare_owner = nlmsvc_same_owner, |
| 689 | .fl_notify = nlmsvc_notify_blocked, |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 690 | .fl_grant = nlmsvc_grant_deferred, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | }; |
| 692 | |
| 693 | /* |
| 694 | * Try to claim a lock that was previously blocked. |
| 695 | * |
| 696 | * Note that we use both the RPC_GRANTED_MSG call _and_ an async |
| 697 | * RPC thread when notifying the client. This seems like overkill... |
| 698 | * Here's why: |
| 699 | * - we don't want to use a synchronous RPC thread, otherwise |
| 700 | * we might find ourselves hanging on a dead portmapper. |
| 701 | * - Some lockd implementations (e.g. HP) don't react to |
| 702 | * RPC_GRANTED calls; they seem to insist on RPC_GRANTED_MSG calls. |
| 703 | */ |
| 704 | static void |
| 705 | nlmsvc_grant_blocked(struct nlm_block *block) |
| 706 | { |
| 707 | struct nlm_file *file = block->b_file; |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 708 | struct nlm_lock *lock = &block->b_call->a_args.lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | int error; |
| 710 | |
| 711 | dprintk("lockd: grant blocked lock %p\n", block); |
| 712 | |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 713 | kref_get(&block->b_count); |
| 714 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 715 | /* Unlink block request from list */ |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 716 | nlmsvc_unlink_block(block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | |
| 718 | /* If b_granted is true this means we've been here before. |
| 719 | * Just retry the grant callback, possibly refreshing the RPC |
| 720 | * binding */ |
| 721 | if (block->b_granted) { |
| 722 | nlm_rebind_host(block->b_host); |
| 723 | goto callback; |
| 724 | } |
| 725 | |
| 726 | /* Try the lock operation again */ |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 727 | lock->fl.fl_flags |= FL_SLEEP; |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 728 | error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); |
Trond Myklebust | 09c7938 | 2006-03-20 13:44:38 -0500 | [diff] [blame] | 729 | lock->fl.fl_flags &= ~FL_SLEEP; |
| 730 | |
Andy Adamson | 5de0e50 | 2006-03-20 13:44:25 -0500 | [diff] [blame] | 731 | switch (error) { |
| 732 | case 0: |
| 733 | break; |
| 734 | case -EAGAIN: |
Marc Eshel | 1a8322b | 2006-11-28 16:27:06 -0500 | [diff] [blame] | 735 | case -EINPROGRESS: |
| 736 | dprintk("lockd: lock still blocked error %d\n", error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | nlmsvc_insert_block(block, NLM_NEVER); |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 738 | nlmsvc_release_block(block); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 739 | return; |
Andy Adamson | 5de0e50 | 2006-03-20 13:44:25 -0500 | [diff] [blame] | 740 | default: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 741 | printk(KERN_WARNING "lockd: unexpected error %d in %s!\n", |
| 742 | -error, __FUNCTION__); |
| 743 | nlmsvc_insert_block(block, 10 * HZ); |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 744 | nlmsvc_release_block(block); |
Trond Myklebust | d9f6eb7 | 2006-03-20 13:44:47 -0500 | [diff] [blame] | 745 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | } |
| 747 | |
| 748 | callback: |
| 749 | /* Lock was granted by VFS. */ |
| 750 | dprintk("lockd: GRANTing blocked lock.\n"); |
| 751 | block->b_granted = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 752 | |
| 753 | /* Schedule next grant callback in 30 seconds */ |
| 754 | nlmsvc_insert_block(block, 30 * HZ); |
| 755 | |
| 756 | /* Call the client */ |
Trond Myklebust | a995e9e | 2007-02-02 15:37:43 -0800 | [diff] [blame] | 757 | nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG, &nlmsvc_grant_ops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | } |
| 759 | |
| 760 | /* |
| 761 | * This is the callback from the RPC layer when the NLM_GRANTED_MSG |
| 762 | * RPC call has succeeded or timed out. |
| 763 | * Like all RPC callbacks, it is invoked by the rpciod process, so it |
| 764 | * better not sleep. Therefore, we put the blocked lock on the nlm_blocked |
| 765 | * chain once more in order to have it removed by lockd itself (which can |
| 766 | * then sleep on the file semaphore without disrupting e.g. the nfs client). |
| 767 | */ |
Trond Myklebust | 963d8fe | 2006-01-03 09:55:04 +0100 | [diff] [blame] | 768 | static void nlmsvc_grant_callback(struct rpc_task *task, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 769 | { |
Trond Myklebust | 963d8fe | 2006-01-03 09:55:04 +0100 | [diff] [blame] | 770 | struct nlm_rqst *call = data; |
Trond Myklebust | 9273723 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 771 | struct nlm_block *block = call->a_block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 772 | unsigned long timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | |
| 774 | dprintk("lockd: GRANT_MSG RPC callback\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | |
| 776 | /* Technically, we should down the file semaphore here. Since we |
| 777 | * move the block towards the head of the queue only, no harm |
| 778 | * can be done, though. */ |
| 779 | if (task->tk_status < 0) { |
| 780 | /* RPC error: Re-insert for retransmission */ |
| 781 | timeout = 10 * HZ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | } else { |
| 783 | /* Call was successful, now wait for client callback */ |
| 784 | timeout = 60 * HZ; |
| 785 | } |
| 786 | nlmsvc_insert_block(block, timeout); |
| 787 | svc_wake_up(block->b_daemon); |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 788 | } |
| 789 | |
Adrian Bunk | ec535ce15 | 2006-04-18 13:21:50 -0400 | [diff] [blame] | 790 | static void nlmsvc_grant_release(void *data) |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 791 | { |
Trond Myklebust | 6041b79 | 2006-03-20 13:44:45 -0500 | [diff] [blame] | 792 | struct nlm_rqst *call = data; |
| 793 | |
| 794 | nlmsvc_release_block(call->a_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | } |
| 796 | |
Trond Myklebust | 963d8fe | 2006-01-03 09:55:04 +0100 | [diff] [blame] | 797 | static const struct rpc_call_ops nlmsvc_grant_ops = { |
| 798 | .rpc_call_done = nlmsvc_grant_callback, |
Trond Myklebust | 5e1abf8 | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 799 | .rpc_release = nlmsvc_grant_release, |
Trond Myklebust | 963d8fe | 2006-01-03 09:55:04 +0100 | [diff] [blame] | 800 | }; |
| 801 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 802 | /* |
| 803 | * We received a GRANT_RES callback. Try to find the corresponding |
| 804 | * block. |
| 805 | */ |
| 806 | void |
Al Viro | e8c5c04 | 2006-12-13 00:35:03 -0800 | [diff] [blame] | 807 | nlmsvc_grant_reply(struct nlm_cookie *cookie, __be32 status) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | { |
| 809 | struct nlm_block *block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | |
Olaf Kirch | 39be450 | 2006-10-04 02:16:03 -0700 | [diff] [blame] | 811 | dprintk("grant_reply: looking for cookie %x, s=%d \n", |
| 812 | *(unsigned int *)(cookie->data), status); |
| 813 | if (!(block = nlmsvc_find_block(cookie))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 814 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | |
J. Bruce Fields | f232142 | 2006-01-03 09:55:42 +0100 | [diff] [blame] | 816 | if (block) { |
Al Viro | e8c5c04 | 2006-12-13 00:35:03 -0800 | [diff] [blame] | 817 | if (status == nlm_lck_denied_grace_period) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 818 | /* Try again in a couple of seconds */ |
| 819 | nlmsvc_insert_block(block, 10 * HZ); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 820 | } else { |
| 821 | /* Lock is now held by client, or has been rejected. |
| 822 | * In both cases, the block should be removed. */ |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 823 | nlmsvc_unlink_block(block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 824 | } |
| 825 | } |
Trond Myklebust | 6849c0c | 2006-03-20 13:44:39 -0500 | [diff] [blame] | 826 | nlmsvc_release_block(block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | } |
| 828 | |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 829 | /* Helper function to handle retry of a deferred block. |
| 830 | * If it is a blocking lock, call grant_blocked. |
| 831 | * For a non-blocking lock or test lock, revisit the request. |
| 832 | */ |
| 833 | static void |
| 834 | retry_deferred_block(struct nlm_block *block) |
| 835 | { |
| 836 | if (!(block->b_flags & B_GOT_CALLBACK)) |
| 837 | block->b_flags |= B_TIMED_OUT; |
| 838 | nlmsvc_insert_block(block, NLM_TIMEOUT); |
| 839 | dprintk("revisit block %p flags %d\n", block, block->b_flags); |
| 840 | if (block->b_deferred_req) { |
| 841 | block->b_deferred_req->revisit(block->b_deferred_req, 0); |
| 842 | block->b_deferred_req = NULL; |
| 843 | } |
| 844 | } |
| 845 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 846 | /* |
| 847 | * Retry all blocked locks that have been notified. This is where lockd |
| 848 | * picks up locks that can be granted, or grant notifications that must |
| 849 | * be retransmitted. |
| 850 | */ |
| 851 | unsigned long |
| 852 | nlmsvc_retry_blocked(void) |
| 853 | { |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 854 | unsigned long timeout = MAX_SCHEDULE_TIMEOUT; |
| 855 | struct nlm_block *block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 857 | while (!list_empty(&nlm_blocked)) { |
| 858 | block = list_entry(nlm_blocked.next, struct nlm_block, b_list); |
| 859 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 860 | if (block->b_when == NLM_NEVER) |
| 861 | break; |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 862 | if (time_after(block->b_when,jiffies)) { |
| 863 | timeout = block->b_when - jiffies; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 864 | break; |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 865 | } |
| 866 | |
J. Bruce Fields | f3d43c7 | 2006-08-03 15:07:47 -0400 | [diff] [blame] | 867 | dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n", |
| 868 | block, block->b_when); |
Marc Eshel | 0e4ac9d | 2006-11-28 16:26:51 -0500 | [diff] [blame] | 869 | if (block->b_flags & B_QUEUED) { |
| 870 | dprintk("nlmsvc_retry_blocked delete block (%p, granted=%d, flags=%d)\n", |
| 871 | block, block->b_granted, block->b_flags); |
| 872 | retry_deferred_block(block); |
| 873 | } else |
| 874 | nlmsvc_grant_blocked(block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 875 | } |
| 876 | |
Olaf Kirch | 68a2d76c | 2006-10-04 02:15:57 -0700 | [diff] [blame] | 877 | return timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 878 | } |