From 1a8322b2b02071b0c7ac37a28357b93e6362f13e Mon Sep 17 00:00:00 2001 From: Marc Eshel Date: Tue, 28 Nov 2006 16:27:06 -0500 Subject: [PATCH] lockd: add code to handle deferred lock requests Rewrite nlmsvc_lock() to use the asynchronous interface. As with testlock, we answer nlm requests in nlmsvc_lock by first looking up the block and then using the results we find in the block if B_QUEUED is set, and calling vfs_lock_file() otherwise. If this a new lock request and we get -EINPROGRESS return on a non-blocking request then we defer the request. Also modify nlmsvc_unlock() to call the filesystem method if appropriate. Signed-off-by: Marc Eshel Signed-off-by: J. Bruce Fields --- fs/lockd/svc4proc.c | 2 ++ fs/lockd/svclock.c | 41 +++++++++++++++++++++++++++++++++++------ fs/lockd/svcproc.c | 2 ++ fs/lockd/svcsubs.c | 2 +- 4 files changed, 40 insertions(+), 7 deletions(-) diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c index 205d8befbf1..bf27b6c6cb6 100644 --- a/fs/lockd/svc4proc.c +++ b/fs/lockd/svc4proc.c @@ -145,6 +145,8 @@ nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp, /* Now try to lock the file */ resp->status = nlmsvc_lock(rqstp, file, &argp->lock, argp->block, &argp->cookie); + if (resp->status == nlm_drop_reply) + return rpc_drop_reply; dprintk("lockd: LOCK status %d\n", ntohl(resp->status)); nlm_release_host(host); diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c index 0d7398e3804..b3efa4536cc 100644 --- a/fs/lockd/svclock.c +++ b/fs/lockd/svclock.c @@ -393,17 +393,43 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, } else lock->fl.fl_flags &= ~FL_SLEEP; - error = posix_lock_file(file->f_file, &lock->fl, NULL); - 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 (!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: + ret = nlm_lck_denied; break; + case -EINPROGRESS: + 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; @@ -535,7 +561,7 @@ nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock) nlmsvc_cancel_blocked(file, lock); lock->fl.fl_type = F_UNLCK; - error = posix_lock_file(file->f_file, &lock->fl, NULL); + error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); return (error < 0)? nlm_lck_denied_nolocks : nlm_granted; } @@ -564,6 +590,8 @@ nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock) block = nlmsvc_lookup_block(file, lock); 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); } @@ -697,14 +725,15 @@ nlmsvc_grant_blocked(struct nlm_block *block) /* Try the lock operation again */ lock->fl.fl_flags |= FL_SLEEP; - error = posix_lock_file(file->f_file, &lock->fl, NULL); + error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); lock->fl.fl_flags &= ~FL_SLEEP; switch (error) { case 0: break; case -EAGAIN: - dprintk("lockd: lock still blocked\n"); + case -EINPROGRESS: + dprintk("lockd: lock still blocked error %d\n", error); nlmsvc_insert_block(block, NLM_NEVER); nlmsvc_release_block(block); return; diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c index 40b5cf496b5..9cd5c8b3759 100644 --- a/fs/lockd/svcproc.c +++ b/fs/lockd/svcproc.c @@ -175,6 +175,8 @@ nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp, /* Now try to lock the file */ resp->status = cast_status(nlmsvc_lock(rqstp, file, &argp->lock, argp->block, &argp->cookie)); + if (resp->status == nlm_drop_reply) + return rpc_drop_reply; dprintk("lockd: LOCK status %d\n", ntohl(resp->status)); nlm_release_host(host); diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c index 50957089be1..84ebba33b98 100644 --- a/fs/lockd/svcsubs.c +++ b/fs/lockd/svcsubs.c @@ -182,7 +182,7 @@ again: lock.fl_type = F_UNLCK; lock.fl_start = 0; lock.fl_end = OFFSET_MAX; - if (posix_lock_file(file->f_file, &lock, NULL) < 0) { + if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) { printk("lockd: unlock failure in %s:%d\n", __FILE__, __LINE__); return 1; -- 2.20.1