diff options
| -rw-r--r-- | fs/lockd/svclock.c | 91 |
1 files changed, 87 insertions, 4 deletions
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c index f244926..6e74857 100644 --- a/fs/lockd/svclock.c +++ b/fs/lockd/svclock.c @@ -261,6 +261,7 @@ static void nlmsvc_free_block(struct kref *kref) nlmsvc_freegrantargs(block->b_call); nlm_release_call(block->b_call); nlm_release_file(block->b_file); + kfree(block->b_fl); kfree(block); } @@ -528,6 +529,64 @@ 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 fl_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) { + block->b_fl = kzalloc(sizeof(struct file_lock), GFP_KERNEL); + 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; + + lock_kernel(); + 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(block, 0); + svc_wake_up(block->b_daemon); + rc = 0; + break; + } + } + unlock_kernel(); + 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. * @@ -559,6 +618,7 @@ static int nlmsvc_same_owner(struct file_lock *fl1, struct file_lock *fl2) struct lock_manager_operations nlmsvc_lock_operations = { .fl_compare_owner = nlmsvc_same_owner, .fl_notify = nlmsvc_notify_blocked, + .fl_grant = nlmsvc_grant_deferred, }; /* @@ -581,6 +641,8 @@ nlmsvc_grant_blocked(struct nlm_block *block) dprintk("lockd: grant blocked lock %p\n", block); + kref_get(&block->b_count); + /* Unlink block request from list */ nlmsvc_unlink_block(block); @@ -603,11 +665,13 @@ nlmsvc_grant_blocked(struct nlm_block *block) case -EAGAIN: dprintk("lockd: lock still blocked\n"); nlmsvc_insert_block(block, NLM_NEVER); + nlmsvc_release_block(block); return; default: printk(KERN_WARNING "lockd: unexpected error %d in %s!\n", -error, __FUNCTION__); nlmsvc_insert_block(block, 10 * HZ); + nlmsvc_release_block(block); return; } @@ -620,7 +684,6 @@ callback: nlmsvc_insert_block(block, 30 * HZ); /* Call the client */ - kref_get(&block->b_count); nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG, &nlmsvc_grant_ops); } @@ -693,6 +756,23 @@ nlmsvc_grant_reply(struct nlm_cookie *cookie, __be32 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 @@ -716,9 +796,12 @@ nlmsvc_retry_blocked(void) 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); } return timeout; |
