diff options
| author | Alexander Aring <aahringo@redhat.com> | 2023-09-12 17:53:19 -0400 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2023-09-17 19:05:43 -0400 |
| commit | 7f1c56c5904695bebb46083c889f63f8ea52eebd (patch) | |
| tree | b4146585de47bfb50a963b325bc61ab11d26caf6 | |
| parent | e662734d643fa5c6b15ff40a8e89b2d4dca25cee (diff) | |
| download | linux-7f1c56c5904695bebb46083c889f63f8ea52eebd.tar.gz | |
lockd: don't call vfs_lock_file() for pending requests
This patch returns nlm_lck_blocked in nlmsvc_lock() when an asynchronous
lock request is pending. During testing I ran into the case with the
side-effects that lockd is waiting for only one lm_grant() callback
because it's already part of the nlm_blocked list. If another
asynchronous for the same nlm_block is triggered two lm_grant()
callbacks will occur but lockd was only waiting for one.
To avoid any change of existing users this handling will only being made
when export_op_support_safe_async_lock() returns true.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
| -rw-r--r-- | fs/lockd/svclock.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c index d500e32ebb18bf..c313622a957876 100644 --- a/fs/lockd/svclock.c +++ b/fs/lockd/svclock.c @@ -541,6 +541,22 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, goto out; } + spin_lock(&nlm_blocked_lock); + /* + * If this is a lock request for an already pending + * lock request we return nlm_lck_blocked without calling + * vfs_lock_file() again. Otherwise we have two pending + * requests on the underlaying ->lock() implementation but + * only one nlm_block to being granted by lm_grant(). + */ + if (exportfs_lock_op_is_async(inode->i_sb->s_export_op) && + !list_empty(&block->b_list)) { + spin_unlock(&nlm_blocked_lock); + ret = nlm_lck_blocked; + goto out; + } + spin_unlock(&nlm_blocked_lock); + if (!wait) lock->fl.fl_flags &= ~FL_SLEEP; mode = lock_to_openmode(&lock->fl); @@ -553,13 +569,6 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, ret = nlm_granted; goto out; case -EAGAIN: - /* - * If this is a blocking request for an - * already pending lock request then we need - * to put it back on lockd's block list - */ - if (wait) - break; ret = async_block ? nlm_lck_blocked : nlm_lck_denied; goto out; case FILE_LOCK_DEFERRED: |