This is a note to let you know that I've just added the patch titled ext4: fix scheduling in atomic on group checksum failure to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ext4-fix-scheduling-in-atomic-on-group-checksum-failure.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 05145bd799e498ce4e3b5145894174ee881f02b0 Mon Sep 17 00:00:00 2001 From: Jan Kara <jack@xxxxxxx> Date: Thu, 11 Feb 2016 23:15:12 -0500 Subject: ext4: fix scheduling in atomic on group checksum failure From: Jan Kara <jack@xxxxxxx> commit 05145bd799e498ce4e3b5145894174ee881f02b0 upstream. When block group checksum is wrong, we call ext4_error() while holding group spinlock from ext4_init_block_bitmap() or ext4_init_inode_bitmap() which results in scheduling while in atomic. Fix the issue by calling ext4_error() later after dropping the spinlock. Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Signed-off-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/balloc.c | 7 ++++--- fs/ext4/ialloc.c | 6 ++++-- 2 files changed, 8 insertions(+), 5 deletions(-) --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -191,7 +191,6 @@ static int ext4_init_block_bitmap(struct /* If checksum is bad mark all blocks used to prevent allocation * essentially implementing a per-group read-only flag. */ if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { - ext4_error(sb, "Checksum bad for group %u", block_group); grp = ext4_get_group_info(sb, block_group); if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) percpu_counter_sub(&sbi->s_freeclusters_counter, @@ -442,14 +441,16 @@ ext4_read_block_bitmap_nowait(struct sup } ext4_lock_group(sb, block_group); if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { - err = ext4_init_block_bitmap(sb, bh, block_group, desc); set_bitmap_uptodate(bh); set_buffer_uptodate(bh); ext4_unlock_group(sb, block_group); unlock_buffer(bh); - if (err) + if (err) { + ext4_error(sb, "Failed to init block bitmap for group " + "%u: %d", block_group, err); goto out; + } goto verify; } ext4_unlock_group(sb, block_group); --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -76,7 +76,6 @@ static int ext4_init_inode_bitmap(struct /* If checksum is bad mark all blocks and inodes use to prevent * allocation, essentially implementing a per-group read-only flag. */ if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { - ext4_error(sb, "Checksum bad for group %u", block_group); grp = ext4_get_group_info(sb, block_group); if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) percpu_counter_sub(&sbi->s_freeclusters_counter, @@ -191,8 +190,11 @@ ext4_read_inode_bitmap(struct super_bloc set_buffer_verified(bh); ext4_unlock_group(sb, block_group); unlock_buffer(bh); - if (err) + if (err) { + ext4_error(sb, "Failed to init inode bitmap for group " + "%u: %d", block_group, err); goto out; + } return bh; } ext4_unlock_group(sb, block_group); Patches currently in stable-queue which might be from jack@xxxxxxx are queue-4.4/udf-check-output-buffer-length-when-converting-name-to-cs0.patch queue-4.4/udf-limit-the-maximum-number-of-indirect-extents-in-a-row.patch queue-4.4/ext4-fix-scheduling-in-atomic-on-group-checksum-failure.patch queue-4.4/udf-prevent-buffer-overrun-with-multi-byte-characters.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html