lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ext4: lock block groups when initializing

Browse Source 
I noticed when filling a 1T filesystem with 4 threads using the
fs_mark benchmark:

fs_mark -d /mnt/test -D 256 -n 100000 -t 4 -s 20480 -F -S 0

that I occasionally got checksum mismatch errors:

EXT4-fs error (device sdb): ext4_init_inode_bitmap: Checksum bad for group 6935

etc.  I'd reliably get 4-5 of them during the run.

It appears that the problem is likely a race to init the bg's
when the uninit_bg feature is enabled.

With the patch below, which adds sb_bgl_locking around initialization,
I was able to complete several runs with no errors or warnings.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Eric Sandeen
2008-08-02 21:21:08 -04:00
committed by Theodore Ts'o
parent e29d1cde63
commit b5f10eed81
4 changed files with 12 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
fs/ext4/super.c
View File

@@ -1621,6 +1621,7 @@ static int ext4_check_descriptors(struct super_block *sb)
"(block %llu)!", i, inode_table);
return 0;
}
spin_lock(sb_bgl_lock(sbi, i));
if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
"Checksum for group %lu failed (%u!=%u)\n",
@@ -1629,6 +1630,7 @@ static int ext4_check_descriptors(struct super_block *sb)
if (!(sb->s_flags & MS_RDONLY))
return 0;
}
spin_unlock(sb_bgl_lock(sbi, i));
if (!flexbg_flag)
first_block += EXT4_BLOCKS_PER_GROUP(sb);
}