Btrfs: fix autodefrag and umount lockup
This happens because writeback_inodes_sb_nr_if_idle does down_read. This
doesn't work for us and it has not been fixed upstream yet, so do it
ourselves and use that instead so we can stop having this stupid long
standing lockup. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b9526f7..afc3ac5 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3689,6 +3689,20 @@
return 0;
}
+static int writeback_inodes_sb_nr_if_idle_safe(struct super_block *sb,
+ unsigned long nr_pages,
+ enum wb_reason reason)
+{
+ if (!writeback_in_progress(sb->s_bdi) &&
+ down_read_trylock(&sb->s_umount)) {
+ writeback_inodes_sb_nr(sb, nr_pages, reason);
+ up_read(&sb->s_umount);
+ return 1;
+ }
+
+ return 0;
+}
+
/*
* shrink metadata reservation for delalloc
*/
@@ -3721,8 +3735,9 @@
while (delalloc_bytes && loops < 3) {
max_reclaim = min(delalloc_bytes, to_reclaim);
nr_pages = max_reclaim >> PAGE_CACHE_SHIFT;
- writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages,
- WB_REASON_FS_FREE_SPACE);
+ writeback_inodes_sb_nr_if_idle_safe(root->fs_info->sb,
+ nr_pages,
+ WB_REASON_FS_FREE_SPACE);
/*
* We need to wait for the async pages to actually start before