diff options
Diffstat (limited to 'fs/lockd/svclock.c')
| -rw-r--r-- | fs/lockd/svclock.c | 691 |
1 files changed, 479 insertions, 212 deletions
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c index c9d419703cf..ab798a88ec1 100644 --- a/fs/lockd/svclock.c +++ b/fs/lockd/svclock.c @@ -21,14 +21,15 @@ */ #include <linux/types.h> +#include <linux/slab.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/sched.h> -#include <linux/smp_lock.h> #include <linux/sunrpc/clnt.h> -#include <linux/sunrpc/svc.h> +#include <linux/sunrpc/svc_xprt.h> #include <linux/lockd/nlm.h> #include <linux/lockd/lockd.h> +#include <linux/kthread.h> #define NLMDBG_FACILITY NLMDBG_SVCLOCK @@ -40,7 +41,7 @@ static void nlmsvc_release_block(struct nlm_block *block); static void nlmsvc_insert_block(struct nlm_block *block, unsigned long); -static int nlmsvc_remove_block(struct nlm_block *block); +static void nlmsvc_remove_block(struct nlm_block *block); static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock); static void nlmsvc_freegrantargs(struct nlm_rqst *call); @@ -49,56 +50,91 @@ static const struct rpc_call_ops nlmsvc_grant_ops; /* * The list of blocked locks to retry */ -static struct nlm_block * nlm_blocked; +static LIST_HEAD(nlm_blocked); +static DEFINE_SPINLOCK(nlm_blocked_lock); + +#ifdef LOCKD_DEBUG +static const char *nlmdbg_cookie2a(const struct nlm_cookie *cookie) +{ + /* + * We can get away with a static buffer because we're only + * called with BKL held. + */ + static char buf[2*NLM_MAXCOOKIELEN+1]; + unsigned int i, len = sizeof(buf); + char *p = buf; + + len--; /* allow for trailing \0 */ + if (len < 3) + return "???"; + for (i = 0 ; i < cookie->len ; i++) { + if (len < 2) { + strcpy(p-3, "..."); + break; + } + sprintf(p, "%02x", cookie->data[i]); + p += 2; + len -= 2; + } + *p = '\0'; + + return buf; +} +#endif /* * Insert a blocked lock into the global list */ static void -nlmsvc_insert_block(struct nlm_block *block, unsigned long when) +nlmsvc_insert_block_locked(struct nlm_block *block, unsigned long when) { - struct nlm_block **bp, *b; + struct nlm_block *b; + struct list_head *pos; dprintk("lockd: nlmsvc_insert_block(%p, %ld)\n", block, when); - kref_get(&block->b_count); - if (block->b_queued) - nlmsvc_remove_block(block); - bp = &nlm_blocked; + if (list_empty(&block->b_list)) { + kref_get(&block->b_count); + } else { + list_del_init(&block->b_list); + } + + pos = &nlm_blocked; if (when != NLM_NEVER) { if ((when += jiffies) == NLM_NEVER) when ++; - while ((b = *bp) && time_before_eq(b->b_when,when) && b->b_when != NLM_NEVER) - bp = &b->b_next; - } else - while ((b = *bp) != 0) - bp = &b->b_next; + list_for_each(pos, &nlm_blocked) { + b = list_entry(pos, struct nlm_block, b_list); + if (time_after(b->b_when,when) || b->b_when == NLM_NEVER) + break; + } + /* On normal exit from the loop, pos == &nlm_blocked, + * so we will be adding to the end of the list - good + */ + } - block->b_queued = 1; + list_add_tail(&block->b_list, pos); block->b_when = when; - block->b_next = b; - *bp = block; +} + +static void nlmsvc_insert_block(struct nlm_block *block, unsigned long when) +{ + spin_lock(&nlm_blocked_lock); + nlmsvc_insert_block_locked(block, when); + spin_unlock(&nlm_blocked_lock); } /* * Remove a block from the global list */ -static int +static inline void nlmsvc_remove_block(struct nlm_block *block) { - struct nlm_block **bp, *b; - - if (!block->b_queued) - return 1; - for (bp = &nlm_blocked; (b = *bp) != 0; bp = &b->b_next) { - if (b == block) { - *bp = block->b_next; - block->b_queued = 0; - nlmsvc_release_block(block); - return 1; - } + if (!list_empty(&block->b_list)) { + spin_lock(&nlm_blocked_lock); + list_del_init(&block->b_list); + spin_unlock(&nlm_blocked_lock); + nlmsvc_release_block(block); } - - return 0; } /* @@ -107,14 +143,14 @@ nlmsvc_remove_block(struct nlm_block *block) static struct nlm_block * nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock) { - struct nlm_block **head, *block; + struct nlm_block *block; struct file_lock *fl; dprintk("lockd: nlmsvc_lookup_block f=%p pd=%d %Ld-%Ld ty=%d\n", file, lock->fl.fl_pid, (long long)lock->fl.fl_start, (long long)lock->fl.fl_end, lock->fl.fl_type); - for (head = &nlm_blocked; (block = *head) != 0; head = &block->b_next) { + list_for_each_entry(block, &nlm_blocked, b_list) { fl = &block->b_call->a_args.lock.fl; dprintk("lockd: check f=%p pd=%d %Ld-%Ld ty=%d cookie=%s\n", block->b_file, fl->fl_pid, @@ -132,9 +168,9 @@ nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock) static inline int nlm_cookie_match(struct nlm_cookie *a, struct nlm_cookie *b) { - if(a->len != b->len) + if (a->len != b->len) return 0; - if(memcmp(a->data,b->data,a->len)) + if (memcmp(a->data, b->data, a->len)) return 0; return 1; } @@ -143,20 +179,20 @@ static inline int nlm_cookie_match(struct nlm_cookie *a, struct nlm_cookie *b) * Find a block with a given NLM cookie. */ static inline struct nlm_block * -nlmsvc_find_block(struct nlm_cookie *cookie, struct sockaddr_in *sin) +nlmsvc_find_block(struct nlm_cookie *cookie) { struct nlm_block *block; - for (block = nlm_blocked; block; block = block->b_next) { - dprintk("cookie: head of blocked queue %p, block %p\n", - nlm_blocked, block); - if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie) - && nlm_cmp_addr(sin, &block->b_host->h_addr)) - break; + list_for_each_entry(block, &nlm_blocked, b_list) { + if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie)) + goto found; } - if (block != NULL) - kref_get(&block->b_count); + return NULL; + +found: + dprintk("nlmsvc_find_block(%s): block=%p\n", nlmdbg_cookie2a(cookie), block); + kref_get(&block->b_count); return block; } @@ -169,20 +205,20 @@ nlmsvc_find_block(struct nlm_cookie *cookie, struct sockaddr_in *sin) * request, but (as I found out later) that's because some implementations * do just this. Never mind the standards comittees, they support our * logging industries. + * + * 10 years later: I hope we can safely ignore these old and broken + * clients by now. Let's fix this so we can uniquely identify an incoming + * GRANTED_RES message by cookie, without having to rely on the client's IP + * address. --okir */ -static inline struct nlm_block * -nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file, - struct nlm_lock *lock, struct nlm_cookie *cookie) +static struct nlm_block * +nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host, + struct nlm_file *file, struct nlm_lock *lock, + struct nlm_cookie *cookie) { struct nlm_block *block; - struct nlm_host *host; struct nlm_rqst *call = NULL; - /* Create host handle for callback */ - host = nlmsvc_lookup_host(rqstp); - if (host == NULL) - return NULL; - call = nlm_alloc_call(host); if (call == NULL) return NULL; @@ -192,6 +228,8 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file, if (block == NULL) goto failed; kref_init(&block->b_count); + INIT_LIST_HEAD(&block->b_list); + INIT_LIST_HEAD(&block->b_flist); if (!nlmsvc_setgrantargs(call, lock)) goto failed_free; @@ -199,7 +237,7 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file, /* Set notifier function for VFS, and init args */ call->a_args.lock.fl.fl_flags |= FL_SLEEP; call->a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations; - call->a_args.cookie = *cookie; /* see above */ + nlmclnt_next_cookie(&call->a_args.cookie); dprintk("lockd: created block %p...\n", block); @@ -207,11 +245,11 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file, block->b_daemon = rqstp->rq_server; block->b_host = host; block->b_file = file; + block->b_fl = NULL; file->f_count++; /* Add to file's list of blocks */ - block->b_fnext = file->f_blocks; - file->f_blocks = block; + list_add(&block->b_flist, &file->f_blocks); /* Set up RPC arguments for callback */ block->b_call = call; @@ -223,13 +261,12 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file, failed_free: kfree(block); failed: - nlm_release_call(call); + nlmsvc_release_call(call); return NULL; } /* - * Delete a block. If the lock was cancelled or the grant callback - * failed, unlock is set to 1. + * Delete a block. * It is the caller's responsibility to check whether the file * can be closed hereafter. */ @@ -239,7 +276,7 @@ static int nlmsvc_unlink_block(struct nlm_block *block) dprintk("lockd: unlinking block %p...\n", block); /* Remove block from list */ - status = posix_unblock_lock(block->b_file->f_file, &block->b_call->a_args.lock.fl); + status = posix_unblock_lock(&block->b_call->a_args.lock.fl); nlmsvc_remove_block(block); return status; } @@ -248,73 +285,52 @@ static void nlmsvc_free_block(struct kref *kref) { struct nlm_block *block = container_of(kref, struct nlm_block, b_count); struct nlm_file *file = block->b_file; - struct nlm_block **bp; dprintk("lockd: freeing block %p...\n", block); - down(&file->f_sema); /* Remove block from file's list of blocks */ - for (bp = &file->f_blocks; *bp; bp = &(*bp)->b_fnext) { - if (*bp == block) { - *bp = block->b_fnext; - break; - } - } - up(&file->f_sema); + list_del_init(&block->b_flist); + mutex_unlock(&file->f_mutex); nlmsvc_freegrantargs(block->b_call); - nlm_release_call(block->b_call); + nlmsvc_release_call(block->b_call); nlm_release_file(block->b_file); + kfree(block->b_fl); kfree(block); } static void nlmsvc_release_block(struct nlm_block *block) { if (block != NULL) - kref_put(&block->b_count, nlmsvc_free_block); + kref_put_mutex(&block->b_count, nlmsvc_free_block, &block->b_file->f_mutex); } -static void nlmsvc_act_mark(struct nlm_host *host, struct nlm_file *file) -{ - struct nlm_block *block; - - down(&file->f_sema); - for (block = file->f_blocks; block != NULL; block = block->b_fnext) - block->b_host->h_inuse = 1; - up(&file->f_sema); -} - -static void nlmsvc_act_unlock(struct nlm_host *host, struct nlm_file *file) +/* + * Loop over all blocks and delete blocks held by + * a matching host. + */ +void nlmsvc_traverse_blocks(struct nlm_host *host, + struct nlm_file *file, + nlm_host_match_fn_t match) { - struct nlm_block *block; + struct nlm_block *block, *next; restart: - down(&file->f_sema); - for (block = file->f_blocks; block != NULL; block = block->b_fnext) { - if (host != NULL && host != block->b_host) + mutex_lock(&file->f_mutex); + list_for_each_entry_safe(block, next, &file->f_blocks, b_flist) { + if (!match(block->b_host, host)) continue; - if (!block->b_queued) + /* Do not destroy blocks that are not on + * the global retry list - why? */ + if (list_empty(&block->b_list)) continue; kref_get(&block->b_count); - up(&file->f_sema); + mutex_unlock(&file->f_mutex); nlmsvc_unlink_block(block); nlmsvc_release_block(block); goto restart; } - up(&file->f_sema); -} - -/* - * Loop over all blocks and perform the action specified. - * (NLM_ACT_CHECK handled by nlmsvc_inspect_file). - */ -void -nlmsvc_traverse_blocks(struct nlm_host *host, struct nlm_file *file, int action) -{ - if (action == NLM_ACT_MARK) - nlmsvc_act_mark(host, file); - else - nlmsvc_act_unlock(host, file); + mutex_unlock(&file->f_mutex); } /* @@ -325,7 +341,7 @@ static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock) { locks_copy_lock(&call->a_args.lock.fl, &lock->fl); memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh)); - call->a_args.lock.caller = system_utsname.nodename; + call->a_args.lock.caller = utsname()->nodename; call->a_args.lock.oh.len = lock->oh.len; /* set default data area */ @@ -347,52 +363,124 @@ static void nlmsvc_freegrantargs(struct nlm_rqst *call) { if (call->a_args.lock.oh.data != call->a_owner) kfree(call->a_args.lock.oh.data); + + locks_release_private(&call->a_args.lock.fl); +} + +/* + * Deferred lock request handling for non-blocking lock + */ +static __be32 +nlmsvc_defer_lock_rqst(struct svc_rqst *rqstp, struct nlm_block *block) +{ + __be32 status = nlm_lck_denied_nolocks; + + block->b_flags |= B_QUEUED; + + nlmsvc_insert_block(block, NLM_TIMEOUT); + + block->b_cache_req = &rqstp->rq_chandle; + if (rqstp->rq_chandle.defer) { + block->b_deferred_req = + rqstp->rq_chandle.defer(block->b_cache_req); + if (block->b_deferred_req != NULL) + status = nlm_drop_reply; + } + dprintk("lockd: nlmsvc_defer_lock_rqst block %p flags %d status %d\n", + block, block->b_flags, ntohl(status)); + + return status; } /* * Attempt to establish a lock, and if it can't be granted, block it * if required. */ -u32 +__be32 nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, - struct nlm_lock *lock, int wait, struct nlm_cookie *cookie) + struct nlm_host *host, struct nlm_lock *lock, int wait, + struct nlm_cookie *cookie, int reclaim) { - struct nlm_block *block, *newblock = NULL; + struct nlm_block *block = NULL; int error; - u32 ret; + __be32 ret; dprintk("lockd: nlmsvc_lock(%s/%ld, ty=%d, pi=%d, %Ld-%Ld, bl=%d)\n", - file->f_file->f_dentry->d_inode->i_sb->s_id, - file->f_file->f_dentry->d_inode->i_ino, + file_inode(file->f_file)->i_sb->s_id, + file_inode(file->f_file)->i_ino, lock->fl.fl_type, lock->fl.fl_pid, (long long)lock->fl.fl_start, (long long)lock->fl.fl_end, wait); - - lock->fl.fl_flags &= ~FL_SLEEP; -again: /* Lock file against concurrent access */ - down(&file->f_sema); - /* Get existing block (in case client is busy-waiting) */ + mutex_lock(&file->f_mutex); + /* Get existing block (in case client is busy-waiting) + * or create new block + */ block = nlmsvc_lookup_block(file, lock); if (block == NULL) { - if (newblock != NULL) - lock = &newblock->b_call->a_args.lock; - } else + block = nlmsvc_create_block(rqstp, host, file, lock, cookie); + ret = nlm_lck_denied_nolocks; + if (block == NULL) + goto out; lock = &block->b_call->a_args.lock; + } else + lock->fl.fl_flags &= ~FL_SLEEP; - error = posix_lock_file(file->f_file, &lock->fl); - lock->fl.fl_flags &= ~FL_SLEEP; + if (block->b_flags & B_QUEUED) { + dprintk("lockd: nlmsvc_lock deferred block %p flags %d\n", + block, block->b_flags); + if (block->b_granted) { + nlmsvc_unlink_block(block); + ret = nlm_granted; + goto out; + } + if (block->b_flags & B_TIMED_OUT) { + nlmsvc_unlink_block(block); + ret = nlm_lck_denied; + goto out; + } + ret = nlm_drop_reply; + goto out; + } - dprintk("lockd: posix_lock_file returned %d\n", error); + if (locks_in_grace(SVC_NET(rqstp)) && !reclaim) { + ret = nlm_lck_denied_grace_period; + goto out; + } + if (reclaim && !locks_in_grace(SVC_NET(rqstp))) { + ret = nlm_lck_denied_grace_period; + goto out; + } - switch(error) { + if (!wait) + lock->fl.fl_flags &= ~FL_SLEEP; + error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); + lock->fl.fl_flags &= ~FL_SLEEP; + + dprintk("lockd: vfs_lock_file returned %d\n", error); + switch (error) { case 0: ret = nlm_granted; goto out; case -EAGAIN: - break; + /* + * If this is a blocking request for an + * already pending lock request then we need + * to put it back on lockd's block list + */ + if (wait) + break; + ret = nlm_lck_denied; + goto out; + case FILE_LOCK_DEFERRED: + if (wait) + break; + /* Filesystem lock operation is in progress + Add it to the queue waiting for callback */ + ret = nlmsvc_defer_lock_rqst(rqstp, block); + goto out; case -EDEADLK: ret = nlm_deadlock; goto out; @@ -401,31 +489,12 @@ again: goto out; } - ret = nlm_lck_denied; - if (!wait) - goto out; - ret = nlm_lck_blocked; - if (block != NULL) - goto out; - - /* If we don't have a block, create and initialize it. Then - * retry because we may have slept in kmalloc. */ - /* We have to release f_sema as nlmsvc_create_block may try to - * to claim it while doing host garbage collection */ - if (newblock == NULL) { - up(&file->f_sema); - dprintk("lockd: blocking on this lock (allocating).\n"); - if (!(newblock = nlmsvc_create_block(rqstp, file, lock, cookie))) - return nlm_lck_denied_nolocks; - goto again; - } /* Append to list of blocked */ - nlmsvc_insert_block(newblock, NLM_NEVER); + nlmsvc_insert_block(block, NLM_NEVER); out: - up(&file->f_sema); - nlmsvc_release_block(newblock); + mutex_unlock(&file->f_mutex); nlmsvc_release_block(block); dprintk("lockd: nlmsvc_lock returned %u\n", ret); return ret; @@ -434,29 +503,94 @@ out: /* * Test for presence of a conflicting lock. */ -u32 -nlmsvc_testlock(struct nlm_file *file, struct nlm_lock *lock, - struct nlm_lock *conflock) +__be32 +nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file, + struct nlm_host *host, struct nlm_lock *lock, + struct nlm_lock *conflock, struct nlm_cookie *cookie) { + struct nlm_block *block = NULL; + int error; + __be32 ret; + dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n", - file->f_file->f_dentry->d_inode->i_sb->s_id, - file->f_file->f_dentry->d_inode->i_ino, + file_inode(file->f_file)->i_sb->s_id, + file_inode(file->f_file)->i_ino, lock->fl.fl_type, (long long)lock->fl.fl_start, (long long)lock->fl.fl_end); - if (posix_test_lock(file->f_file, &lock->fl, &conflock->fl)) { - dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n", - conflock->fl.fl_type, - (long long)conflock->fl.fl_start, - (long long)conflock->fl.fl_end); - conflock->caller = "somehost"; /* FIXME */ - conflock->oh.len = 0; /* don't return OH info */ - conflock->svid = conflock->fl.fl_pid; - return nlm_lck_denied; + /* Get existing block (in case client is busy-waiting) */ + block = nlmsvc_lookup_block(file, lock); + + if (block == NULL) { + struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL); + + if (conf == NULL) + return nlm_granted; + block = nlmsvc_create_block(rqstp, host, file, lock, cookie); + if (block == NULL) { + kfree(conf); + return nlm_granted; + } + block->b_fl = conf; + } + if (block->b_flags & B_QUEUED) { + dprintk("lockd: nlmsvc_testlock deferred block %p flags %d fl %p\n", + block, block->b_flags, block->b_fl); + if (block->b_flags & B_TIMED_OUT) { + nlmsvc_unlink_block(block); + ret = nlm_lck_denied; + goto out; + } + if (block->b_flags & B_GOT_CALLBACK) { + nlmsvc_unlink_block(block); + if (block->b_fl != NULL + && block->b_fl->fl_type != F_UNLCK) { + lock->fl = *block->b_fl; + goto conf_lock; + } else { + ret = nlm_granted; + goto out; + } + } + ret = nlm_drop_reply; + goto out; } - return nlm_granted; + if (locks_in_grace(SVC_NET(rqstp))) { + ret = nlm_lck_denied_grace_period; + goto out; + } + error = vfs_test_lock(file->f_file, &lock->fl); + if (error == FILE_LOCK_DEFERRED) { + ret = nlmsvc_defer_lock_rqst(rqstp, block); + goto out; + } + if (error) { + ret = nlm_lck_denied_nolocks; + goto out; + } + if (lock->fl.fl_type == F_UNLCK) { + ret = nlm_granted; + goto out; + } + +conf_lock: + dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n", + lock->fl.fl_type, (long long)lock->fl.fl_start, + (long long)lock->fl.fl_end); + conflock->caller = "somehost"; /* FIXME */ + conflock->len = strlen(conflock->caller); + conflock->oh.len = 0; /* don't return OH info */ + conflock->svid = lock->fl.fl_pid; + conflock->fl.fl_type = lock->fl.fl_type; + conflock->fl.fl_start = lock->fl.fl_start; + conflock->fl.fl_end = lock->fl.fl_end; + ret = nlm_lck_denied; +out: + if (block) + nlmsvc_release_block(block); + return ret; } /* @@ -466,23 +600,23 @@ nlmsvc_testlock(struct nlm_file *file, struct nlm_lock *lock, * afterwards. In this case the block will still be there, and hence * must be removed. */ -u32 -nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock) +__be32 +nlmsvc_unlock(struct net *net, struct nlm_file *file, struct nlm_lock *lock) { int error; dprintk("lockd: nlmsvc_unlock(%s/%ld, pi=%d, %Ld-%Ld)\n", - file->f_file->f_dentry->d_inode->i_sb->s_id, - file->f_file->f_dentry->d_inode->i_ino, + file_inode(file->f_file)->i_sb->s_id, + file_inode(file->f_file)->i_ino, lock->fl.fl_pid, (long long)lock->fl.fl_start, (long long)lock->fl.fl_end); /* First, cancel any lock that might be there */ - nlmsvc_cancel_blocked(file, lock); + nlmsvc_cancel_blocked(net, file, lock); lock->fl.fl_type = F_UNLCK; - error = posix_lock_file(file->f_file, &lock->fl); + error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); return (error < 0)? nlm_lck_denied_nolocks : nlm_granted; } @@ -494,23 +628,28 @@ nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock) * be in progress. * The calling procedure must check whether the file can be closed. */ -u32 -nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock) +__be32 +nlmsvc_cancel_blocked(struct net *net, struct nlm_file *file, struct nlm_lock *lock) { struct nlm_block *block; int status = 0; dprintk("lockd: nlmsvc_cancel(%s/%ld, pi=%d, %Ld-%Ld)\n", - file->f_file->f_dentry->d_inode->i_sb->s_id, - file->f_file->f_dentry->d_inode->i_ino, + file_inode(file->f_file)->i_sb->s_id, + file_inode(file->f_file)->i_ino, lock->fl.fl_pid, (long long)lock->fl.fl_start, (long long)lock->fl.fl_end); - down(&file->f_sema); + if (locks_in_grace(net)) + return nlm_lck_denied_grace_period; + + mutex_lock(&file->f_mutex); block = nlmsvc_lookup_block(file, lock); - up(&file->f_sema); + mutex_unlock(&file->f_mutex); if (block != NULL) { + vfs_cancel_lock(block->b_file->f_file, + &block->b_call->a_args.lock.fl); status = nlmsvc_unlink_block(block); nlmsvc_release_block(block); } @@ -518,6 +657,63 @@ nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock) } /* + * This is a callback from the filesystem for VFS file lock requests. + * It will be used if lm_grant is defined and the filesystem can not + * respond to the request immediately. + * For GETLK request it will copy the reply to the nlm_block. + * For SETLK or SETLKW request it will get the local posix lock. + * In all cases it will move the block to the head of nlm_blocked q where + * nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the + * deferred rpc for GETLK and SETLK. + */ +static void +nlmsvc_update_deferred_block(struct nlm_block *block, struct file_lock *conf, + int result) +{ + block->b_flags |= B_GOT_CALLBACK; + if (result == 0) + block->b_granted = 1; + else + block->b_flags |= B_TIMED_OUT; + if (conf) { + if (block->b_fl) + __locks_copy_lock(block->b_fl, conf); + } +} + +static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf, + int result) +{ + struct nlm_block *block; + int rc = -ENOENT; + + spin_lock(&nlm_blocked_lock); + list_for_each_entry(block, &nlm_blocked, b_list) { + if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) { + dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n", + block, block->b_flags); + if (block->b_flags & B_QUEUED) { + if (block->b_flags & B_TIMED_OUT) { + rc = -ENOLCK; + break; + } + nlmsvc_update_deferred_block(block, conf, result); + } else if (result == 0) + block->b_granted = 1; + + nlmsvc_insert_block_locked(block, 0); + svc_wake_up(block->b_daemon); + rc = 0; + break; + } + } + spin_unlock(&nlm_blocked_lock); + if (rc == -ENOENT) + printk(KERN_WARNING "lockd: grant for unknown block\n"); + return rc; +} + +/* * Unblock a blocked lock request. This is a callback invoked from the * VFS layer when a lock on which we blocked is removed. * @@ -527,17 +723,19 @@ nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock) static void nlmsvc_notify_blocked(struct file_lock *fl) { - struct nlm_block **bp, *block; + struct nlm_block *block; dprintk("lockd: VFS unblock notification for block %p\n", fl); - for (bp = &nlm_blocked; (block = *bp) != 0; bp = &block->b_next) { + spin_lock(&nlm_blocked_lock); + list_for_each_entry(block, &nlm_blocked, b_list) { if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) { - nlmsvc_insert_block(block, 0); + nlmsvc_insert_block_locked(block, 0); + spin_unlock(&nlm_blocked_lock); svc_wake_up(block->b_daemon); return; } } - + spin_unlock(&nlm_blocked_lock); printk(KERN_WARNING "lockd: notification for unknown block!\n"); } @@ -546,9 +744,22 @@ static int nlmsvc_same_owner(struct file_lock *fl1, struct file_lock *fl2) return fl1->fl_owner == fl2->fl_owner && fl1->fl_pid == fl2->fl_pid; } -struct lock_manager_operations nlmsvc_lock_operations = { - .fl_compare_owner = nlmsvc_same_owner, - .fl_notify = nlmsvc_notify_blocked, +/* + * Since NLM uses two "keys" for tracking locks, we need to hash them down + * to one for the blocked_hash. Here, we're just xor'ing the host address + * with the pid in order to create a key value for picking a hash bucket. + */ +static unsigned long +nlmsvc_owner_key(struct file_lock *fl) +{ + return (unsigned long)fl->fl_owner ^ (unsigned long)fl->fl_pid; +} + +const struct lock_manager_operations nlmsvc_lock_operations = { + .lm_compare_owner = nlmsvc_same_owner, + .lm_owner_key = nlmsvc_owner_key, + .lm_notify = nlmsvc_notify_blocked, + .lm_grant = nlmsvc_grant_deferred, }; /* @@ -568,9 +779,12 @@ nlmsvc_grant_blocked(struct nlm_block *block) struct nlm_file *file = block->b_file; struct nlm_lock *lock = &block->b_call->a_args.lock; int error; + loff_t fl_start, fl_end; dprintk("lockd: grant blocked lock %p\n", block); + kref_get(&block->b_count); + /* Unlink block request from list */ nlmsvc_unlink_block(block); @@ -583,21 +797,30 @@ nlmsvc_grant_blocked(struct nlm_block *block) } /* Try the lock operation again */ + /* vfs_lock_file() can mangle fl_start and fl_end, but we need + * them unchanged for the GRANT_MSG + */ lock->fl.fl_flags |= FL_SLEEP; - error = posix_lock_file(file->f_file, &lock->fl); + fl_start = lock->fl.fl_start; + fl_end = lock->fl.fl_end; + error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); lock->fl.fl_flags &= ~FL_SLEEP; + lock->fl.fl_start = fl_start; + lock->fl.fl_end = fl_end; switch (error) { case 0: break; - case -EAGAIN: - dprintk("lockd: lock still blocked\n"); + case FILE_LOCK_DEFERRED: + dprintk("lockd: lock still blocked error %d\n", error); nlmsvc_insert_block(block, NLM_NEVER); + nlmsvc_release_block(block); return; default: printk(KERN_WARNING "lockd: unexpected error %d in %s!\n", - -error, __FUNCTION__); + -error, __func__); nlmsvc_insert_block(block, 10 * HZ); + nlmsvc_release_block(block); return; } @@ -606,14 +829,20 @@ callback: dprintk("lockd: GRANTing blocked lock.\n"); block->b_granted = 1; - /* Schedule next grant callback in 30 seconds */ - nlmsvc_insert_block(block, 30 * HZ); + /* keep block on the list, but don't reattempt until the RPC + * completes or the submission fails + */ + nlmsvc_insert_block(block, NLM_NEVER); - /* Call the client */ - kref_get(&block->b_count); - if (nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG, - &nlmsvc_grant_ops) < 0) - nlmsvc_release_block(block); + /* Call the client -- use a soft RPC task since nlmsvc_retry_blocked + * will queue up a new one if this one times out + */ + error = nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG, + &nlmsvc_grant_ops); + + /* RPC submission failed, wait a bit and retry */ + if (error < 0) + nlmsvc_insert_block(block, 10 * HZ); } /* @@ -632,6 +861,18 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data) dprintk("lockd: GRANT_MSG RPC callback\n"); + spin_lock(&nlm_blocked_lock); + /* if the block is not on a list at this point then it has + * been invalidated. Don't try to requeue it. + * + * FIXME: it's possible that the block is removed from the list + * after this check but before the nlmsvc_insert_block. In that + * case it will be added back. Perhaps we need better locking + * for nlm_blocked? + */ + if (list_empty(&block->b_list)) + goto out; + /* Technically, we should down the file semaphore here. Since we * move the block towards the head of the queue only, no harm * can be done, though. */ @@ -642,14 +883,19 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data) /* Call was successful, now wait for client callback */ timeout = 60 * HZ; } - nlmsvc_insert_block(block, timeout); + nlmsvc_insert_block_locked(block, timeout); svc_wake_up(block->b_daemon); +out: + spin_unlock(&nlm_blocked_lock); } +/* + * FIXME: nlmsvc_release_block() grabs a mutex. This is not allowed for an + * .rpc_release rpc_call_op + */ static void nlmsvc_grant_release(void *data) { struct nlm_rqst *call = data; - nlmsvc_release_block(call->a_block); } @@ -663,20 +909,17 @@ static const struct rpc_call_ops nlmsvc_grant_ops = { * block. */ void -nlmsvc_grant_reply(struct svc_rqst *rqstp, struct nlm_cookie *cookie, u32 status) +nlmsvc_grant_reply(struct nlm_cookie *cookie, __be32 status) { struct nlm_block *block; - struct nlm_file *file; - dprintk("grant_reply: looking for cookie %x, host (%08x), s=%d \n", - *(unsigned int *)(cookie->data), - ntohl(rqstp->rq_addr.sin_addr.s_addr), status); - if (!(block = nlmsvc_find_block(cookie, &rqstp->rq_addr))) + dprintk("grant_reply: looking for cookie %x, s=%d \n", + *(unsigned int *)(cookie->data), status); + if (!(block = nlmsvc_find_block(cookie))) return; - file = block->b_file; if (block) { - if (status == NLM_LCK_DENIED_GRACE_PERIOD) { + if (status == nlm_lck_denied_grace_period) { /* Try again in a couple of seconds */ nlmsvc_insert_block(block, 10 * HZ); } else { @@ -688,6 +931,23 @@ nlmsvc_grant_reply(struct svc_rqst *rqstp, struct nlm_cookie *cookie, u32 status nlmsvc_release_block(block); } +/* Helper function to handle retry of a deferred block. + * If it is a blocking lock, call grant_blocked. + * For a non-blocking lock or test lock, revisit the request. + */ +static void +retry_deferred_block(struct nlm_block *block) +{ + if (!(block->b_flags & B_GOT_CALLBACK)) + block->b_flags |= B_TIMED_OUT; + nlmsvc_insert_block(block, NLM_TIMEOUT); + dprintk("revisit block %p flags %d\n", block, block->b_flags); + if (block->b_deferred_req) { + block->b_deferred_req->revisit(block->b_deferred_req, 0); + block->b_deferred_req = NULL; + } +} + /* * Retry all blocked locks that have been notified. This is where lockd * picks up locks that can be granted, or grant notifications that must @@ -696,25 +956,32 @@ nlmsvc_grant_reply(struct svc_rqst *rqstp, struct nlm_cookie *cookie, u32 status unsigned long nlmsvc_retry_blocked(void) { - struct nlm_block *block; + unsigned long timeout = MAX_SCHEDULE_TIMEOUT; + struct nlm_block *block; + + spin_lock(&nlm_blocked_lock); + while (!list_empty(&nlm_blocked) && !kthread_should_stop()) { + block = list_entry(nlm_blocked.next, struct nlm_block, b_list); - dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n", - nlm_blocked, - nlm_blocked? nlm_blocked->b_when : 0); - while ((block = nlm_blocked) != 0) { if (block->b_when == NLM_NEVER) break; - if (time_after(block->b_when,jiffies)) + if (time_after(block->b_when, jiffies)) { + timeout = block->b_when - jiffies; break; + } + spin_unlock(&nlm_blocked_lock); + dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n", block, block->b_when); - kref_get(&block->b_count); - nlmsvc_grant_blocked(block); - nlmsvc_release_block(block); + if (block->b_flags & B_QUEUED) { + dprintk("nlmsvc_retry_blocked delete block (%p, granted=%d, flags=%d)\n", + block, block->b_granted, block->b_flags); + retry_deferred_block(block); + } else + nlmsvc_grant_blocked(block); + spin_lock(&nlm_blocked_lock); } + spin_unlock(&nlm_blocked_lock); - if ((block = nlm_blocked) && block->b_when != NLM_NEVER) - return (block->b_when - jiffies); - - return MAX_SCHEDULE_TIMEOUT; + return timeout; } |
