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ext4: fix scheduling in atomic on group checksum failure 

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@vger.kernel.org
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Jan Kara 2016-02-11 23:15:12 -05:00 committed by Theodore Ts'o
parent ff978b09f9
commit 05145bd799
2 changed files with 8 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
fs/ext4/balloc.c
View File

@ -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);

6
fs/ext4/ialloc.c
View File

@ -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);