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>

diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index acfa94d5b48967ec21f55e52132df850c15ff6bc..13db95f54176ec0864732177392889c389df2b57 100644 (file)
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -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

diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index 219d79627c05afc2b0766085b73697a4b41bc621..ff82a32871b566401eb0a177a4b0bf45450b8f4d 100644 (file)
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -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 */