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author | Marc Eshel <eshel@almaden.ibm.com> | 2006-12-05 23:48:10 -0500 |
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committer | J. Bruce Fields <bfields@citi.umich.edu> | 2007-05-06 20:38:50 -0400 |
commit | f812048020282fdfa9b72a6cf539c33b6df1fd07 (patch) | |
tree | e4f281027da1f0e907e68b2e26ae5b773a967047 /fs | |
parent | 5ea0d75037b93baa453b4d326c6319968fe91cea (diff) | |
download | op-kernel-dev-f812048020282fdfa9b72a6cf539c33b6df1fd07.zip op-kernel-dev-f812048020282fdfa9b72a6cf539c33b6df1fd07.tar.gz |
lockd: always preallocate block in nlmsvc_lock()
Normally we could skip ever having to allocate a block in the case where
the client asks for a non-blocking lock, or asks for a blocking lock that
succeeds immediately.
However we're going to want to always look up a block first in order to
check whether we're revisiting a deferred lock call, and to be prepared to
handle the case where the filesystem returns -EINPROGRESS--in that case we
want to make sure the lock we've given the filesystem is the one embedded
in the block that we'll use to track the deferred request.
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/lockd/svclock.c | 34 |
1 files changed, 11 insertions, 23 deletions
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c index b7a8174..0d7398e 100644 --- a/fs/lockd/svclock.c +++ b/fs/lockd/svclock.c @@ -365,7 +365,7 @@ __be32 nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, struct nlm_lock *lock, int wait, struct nlm_cookie *cookie) { - struct nlm_block *block, *newblock = NULL; + struct nlm_block *block = NULL; int error; __be32 ret; @@ -378,17 +378,20 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, wait); - lock->fl.fl_flags &= ~FL_SLEEP; -again: /* Lock file against concurrent access */ mutex_lock(&file->f_mutex); - /* Get existing block (in case client is busy-waiting) */ + /* 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, 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, NULL); lock->fl.fl_flags &= ~FL_SLEEP; @@ -414,26 +417,11 @@ again: 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_mutex as nlmsvc_create_block may try to - * to claim it while doing host garbage collection */ - if (newblock == NULL) { - mutex_unlock(&file->f_mutex); - 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: mutex_unlock(&file->f_mutex); - nlmsvc_release_block(newblock); nlmsvc_release_block(block); dprintk("lockd: nlmsvc_lock returned %u\n", ret); return ret; |