From 1135d6df222046a0ec14a1c9335de99907879922 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 14 Dec 2012 13:46:43 -0500 Subject: [PATCH] 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 Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index b9526f749049..afc3ac5e57d7 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3689,6 +3689,20 @@ static int can_overcommit(struct btrfs_root *root, 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 @@ static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig, 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 -- 2.34.1