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lockd: rip out deferred lock handling from testlock codepath 

As Kinglong points out, the nlm_block->b_fl field is no longer used at
all. Also, vfs_test_lock in the generic locking code will only return
FILE_LOCK_DEFERRED if FL_SLEEP is set, and it isn't here.

The only other place that returns that value is the DLM lock code, but
it only does that in dlm_posix_lock, never in dlm_posix_get.

Remove all of the deferred locking code from the testlock codepath
since it doesn't appear to ever be used anyway.

I do have a small concern that this might cause a behavior change in the
case where you have a block already sitting on the list when the
testlock request comes in, but that looks like it doesn't really work
properly anyway. I think it's best to just pass that down to
vfs_test_lock and let the filesystem report that instead of trying to
infer what's going on with the lock by looking at an existing block.

Cc: cluster-devel@redhat.com
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Kinglong Mee <kinglongmee@gmail.com>
This commit is contained in:
Jeff Layton 2014-08-22 10:18:44 -04:00
parent aef9583b23
commit 09802fd2a8
2 changed files with 6 additions and 50 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
fs/lockd/svclock.c
View File

@ -245,7 +245,6 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host,
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 */
@ -295,7 +294,6 @@ static void nlmsvc_free_block(struct kref *kref)
nlmsvc_freegrantargs(block->b_call);
nlmsvc_release_call(block->b_call);
nlm_release_file(block->b_file);
kfree(block->b_fl);
kfree(block);
}
@ -508,7 +506,6 @@ 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;
@ -519,63 +516,26 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
(long long)lock->fl.fl_start,
(long long)lock->fl.fl_end);
/* 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;
}
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) {
/* We can't currently deal with deferred test requests */
if (error == FILE_LOCK_DEFERRED)
WARN_ON_ONCE(1);
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);
@ -589,8 +549,6 @@ conf_lock:
locks_release_private(&lock->fl);
ret = nlm_lck_denied;
out:
if (block)
nlmsvc_release_block(block);
return ret;
}
@ -661,7 +619,6 @@ nlmsvc_cancel_blocked(struct net *net, struct nlm_file *file, struct nlm_lock *l
* 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

1
include/linux/lockd/lockd.h
View File

@ -178,7 +178,6 @@ struct nlm_block {
unsigned char b_granted; /* VFS granted lock */
struct nlm_file * b_file; /* file in question */
struct cache_req * b_cache_req; /* deferred request handling */
struct file_lock * b_fl; /* set for GETLK */
struct cache_deferred_req * b_deferred_req;
unsigned int b_flags; /* block flags */
#define B_QUEUED 1 /* lock queued */