diff options
| author | David Sterba <dsterba@suse.com> | 2018-08-24 18:32:29 +0300 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2018-10-15 18:23:37 +0300 |
| commit | 3280f874576d31b03fe19cbcc23585d96feb4ceb (patch) | |
| tree | f94ff5ae016c6ca99f75c5ae2de455c065d75730 | |
| parent | f556faa46eb4e96d0d0772e74ecf66781e132f72 (diff) | |
| download | linux-3280f874576d31b03fe19cbcc23585d96feb4ceb.tar.xz | |
btrfs: remove btrfs_dev_replace::read_locks
This member seems to be copied from the extent_buffer locking scheme and
is at least used to assert that the read lock/unlock is properly nested.
In some way. While the _inc/_dec are called inside the read lock
section, the asserts are both inside and outside, so the ordering is not
guaranteed and we can see read/inc/dec ordered in any way
(theoretically).
A missing call of btrfs_dev_replace_clear_lock_blocking could cause
unexpected read_locks count, so this at least looks like a valid
assertion, but this will become unnecessary with later updates.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | fs/btrfs/ctree.h | 1 | ||||
| -rw-r--r-- | fs/btrfs/dev-replace.c | 5 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.c | 1 |
3 files changed, 0 insertions, 7 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 36ade217e462..daa273c7e150 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -361,7 +361,6 @@ struct btrfs_dev_replace { struct mutex lock_finishing_cancel_unmount; rwlock_t lock; - atomic_t read_locks; atomic_t blocking_readers; wait_queue_head_t read_lock_wq; diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index ff01740158aa..702fe6a65075 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -964,13 +964,10 @@ int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) void btrfs_dev_replace_read_lock(struct btrfs_dev_replace *dev_replace) { read_lock(&dev_replace->lock); - atomic_inc(&dev_replace->read_locks); } void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace) { - ASSERT(atomic_read(&dev_replace->read_locks) > 0); - atomic_dec(&dev_replace->read_locks); read_unlock(&dev_replace->lock); } @@ -997,7 +994,6 @@ void btrfs_dev_replace_set_lock_blocking( struct btrfs_dev_replace *dev_replace) { /* only set blocking for read lock */ - ASSERT(atomic_read(&dev_replace->read_locks) > 0); atomic_inc(&dev_replace->blocking_readers); read_unlock(&dev_replace->lock); } @@ -1007,7 +1003,6 @@ void btrfs_dev_replace_clear_lock_blocking( struct btrfs_dev_replace *dev_replace) { /* only set blocking for read lock */ - ASSERT(atomic_read(&dev_replace->read_locks) > 0); ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); read_lock(&dev_replace->lock); /* Barrier implied by atomic_dec_and_test */ diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 517484ecad96..79903243877b 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2155,7 +2155,6 @@ static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info) { mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount); rwlock_init(&fs_info->dev_replace.lock); - atomic_set(&fs_info->dev_replace.read_locks, 0); atomic_set(&fs_info->dev_replace.blocking_readers, 0); init_waitqueue_head(&fs_info->replace_wait); init_waitqueue_head(&fs_info->dev_replace.read_lock_wq); |