From b5f10eed8125702929e57cca7e5956b1b9b6d015 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Sat, 2 Aug 2008 21:21:08 -0400 Subject: ext4: lock block groups when initializing 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 Signed-off-by: Theodore Ts'o --- fs/ext4/super.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/ext4/super.c') diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 876e1c62036..511997ef6f0 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -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); } -- cgit v1.2.3