On Wed 31-03-21 20:15:16, Zhang Yi wrote:
> Commit <50122847007> ("ext4: fix check to prevent initializing reserved
> inodes") check the block group zero and prevent initializing reserved
> inodes. But in some special cases, the reserved inode may not all belong
> to the group zero, it may exist into the second group if we format
> filesystem below.
>
> mkfs.ext4 -b 4096 -g 8192 -N 1024 -I 4096 /dev/sda
>
> So, it will end up triggering a false positive report of a corrupted
> file system. This patch fix it by avoid check reserved inodes if no free
> inode blocks will be zeroed.
>
> Fixes: 50122847007 ("ext4: fix check to prevent initializing reserved inodes")
> Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
> Suggested-by: Jan Kara <jack@xxxxxxx>
Thanks! The patch looks good to me. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> Changes since v1:
> - Splict check of used_blks and used_inos to make code more
> comprehensible as Jan suggested.
>
> fs/ext4/ialloc.c | 48 ++++++++++++++++++++++++++++++++----------------
> 1 file changed, 32 insertions(+), 16 deletions(-)
>
> diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
> index 633ae7becd61..5f0c7fe32672 100644
> --- a/fs/ext4/ialloc.c
> +++ b/fs/ext4/ialloc.c
> @@ -1513,6 +1513,7 @@ int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
> handle_t *handle;
> ext4_fsblk_t blk;
> int num, ret = 0, used_blks = 0;
> + unsigned long used_inos = 0;
>
> /* This should not happen, but just to be sure check this */
> if (sb_rdonly(sb)) {
> @@ -1543,22 +1544,37 @@ int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
> * used inodes so we need to skip blocks with used inodes in
> * inode table.
> */
> - if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
> - used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
> - ext4_itable_unused_count(sb, gdp)),
> - sbi->s_inodes_per_block);
> -
> - if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group) ||
> - ((group == 0) && ((EXT4_INODES_PER_GROUP(sb) -
> - ext4_itable_unused_count(sb, gdp)) <
> - EXT4_FIRST_INO(sb)))) {
> - ext4_error(sb, "Something is wrong with group %u: "
> - "used itable blocks: %d; "
> - "itable unused count: %u",
> - group, used_blks,
> - ext4_itable_unused_count(sb, gdp));
> - ret = 1;
> - goto err_out;
> + if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
> + used_inos = EXT4_INODES_PER_GROUP(sb) -
> + ext4_itable_unused_count(sb, gdp);
> + used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
> +
> + /* Bogus inode unused count? */
> + if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
> + ext4_error(sb, "Something is wrong with group %u: "
> + "used itable blocks: %d; "
> + "itable unused count: %u",
> + group, used_blks,
> + ext4_itable_unused_count(sb, gdp));
> + ret = 1;
> + goto err_out;
> + }
> +
> + used_inos += group * EXT4_INODES_PER_GROUP(sb);
> + /*
> + * Are there some uninitialized inodes in the inode table
> + * before the first normal inode?
> + */
> + if ((used_blks != sbi->s_itb_per_group) &&
> + (used_inos < EXT4_FIRST_INO(sb))) {
> + ext4_error(sb, "Something is wrong with group %u: "
> + "itable unused count: %u; "
> + "itables initialized count: %ld",
> + group, ext4_itable_unused_count(sb, gdp),
> + used_inos);
> + ret = 1;
> + goto err_out;
> + }
> }
>
> blk = ext4_inode_table(sb, gdp) + used_blks;
> --
> 2.25.4
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
