On Wed, Feb 10, 2016 at 02:58:30PM +0100, Jan Kara wrote:
> 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.
>
> CC: stable@xxxxxxxxxxxxxxx
> Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
Looks ok, so
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
> fs/ext4/balloc.c | 7 ++++---
> fs/ext4/ialloc.c | 6 ++++--
> 2 files changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
> index ec0668a60678..fe1f50fe764f 100644
> --- a/fs/ext4/balloc.c
> +++ b/fs/ext4/balloc.c
> @@ -191,7 +191,6 @@ static int ext4_init_block_bitmap(struct super_block *sb,
> /* 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 super_block *sb, ext4_group_t block_group)
> }
> 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);
> diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
> index 3fcfd50a2e8a..acc0ad56bf2f 100644
> --- a/fs/ext4/ialloc.c
> +++ b/fs/ext4/ialloc.c
> @@ -76,7 +76,6 @@ static int ext4_init_inode_bitmap(struct super_block *sb,
> /* 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_block *sb, ext4_group_t block_group)
> 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);
> --
> 2.6.2
>
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