If the s_umount is write locked, then the sb is not idle. IOWs, writeback_inodes_sb...if_idle() should be doing down_read_trylock(), not down_read(). So use try_to_writeback_inodes_sb() instead of writeback_inodes_sb_if_idle(). Signed-off-by: Miao Xie <miaox@xxxxxxxxxxxxxx> --- fs/ext4/inode.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c77b0bd..2dccb4d 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2380,7 +2380,7 @@ static int ext4_nonda_switch(struct super_block *sb) * start pushing delalloc when 1/2 of free blocks are dirty. */ if (free_blocks < 2 * dirty_blocks) - writeback_inodes_sb_if_idle(sb, WB_REASON_FS_FREE_SPACE); + try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE); return 0; } -- 1.7.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html