From 3280f874576d31b03fe19cbcc23585d96feb4ceb Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Fri, 24 Aug 2018 17:32:29 +0200
Subject: 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>
---
fs/btrfs/dev-replace.c | 5 -----
1 file changed, 5 deletions(-)
(limited to 'fs/btrfs/dev-replace.c')
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 */
--
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