btrfs: do regular iput instead of delayed iput during extent map shrinking

The extent map shrinker now runs in the system unbound workqueue and no
longer in kswapd context so it can directly do an iput() on inodes even
if that blocks or needs to acquire any lock (we aren't holding any locks
when requesting the delayed iput from the shrinker). So we don't need to
add a delayed iput, wake up the cleaner and delegate the iput() to the
cleaner, which also adds extra contention on the spinlock that protects
the delayed iputs list.

Reported-by: Ivan Shapovalov <intelfx@intelfx.name>
Tested-by: Ivan Shapovalov <intelfx@intelfx.name>
Link: https://lore.kernel.org/linux-btrfs/0414d690ac5680d0d77dfc930606cdc36e42e12f.camel@intelfx.name/
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 8c6b85ffd18f60361c57f33fc37ffa2276887610..7f46abbd6311b292cba96fc9ed9968502ade8919 100644 (file)
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -1256,7 +1256,7 @@ static long btrfs_scan_root(struct btrfs_root *root, struct btrfs_em_shrink_ctx
 
                min_ino = btrfs_ino(inode) + 1;
                fs_info->em_shrinker_last_ino = btrfs_ino(inode);
-               btrfs_add_delayed_iput(inode);
+               iput(&inode->vfs_inode);
 
                if (ctx->scanned >= ctx->nr_to_scan || btrfs_fs_closing(fs_info))
                        break;