Re: [PATCH v3 2/4] ext4: add helper to check quota inums

Jan Kara
2022-10-26T09:39:13Z

On Wed 26-10-22 12:23:08, Baokun Li wrote:
> Before quota is enabled, a check on the preset quota inums in
> ext4_super_block is added to prevent wrong quota inodes from being loaded.
> In addition, when the quota fails to be enabled, the quota type and quota
> inum are printed to facilitate fault locating.
>
> Signed-off-by: Baokun Li <libaokun1@huawei.com>

Makes sense. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/ext4/super.c | 28 +++++++++++++++++++++++++---
> 1 file changed, 25 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 34b78f380968..0b4060d52d63 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -6885,6 +6885,20 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
> return err;
> }
>
> +static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
> +{
> + switch (type) {
> + case USRQUOTA:
> + return qf_inum == EXT4_USR_QUOTA_INO;
> + case GRPQUOTA:
> + return qf_inum == EXT4_GRP_QUOTA_INO;
> + case PRJQUOTA:
> + return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
> + default:
> + BUG();
> + }
> +}
> +
> static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
> unsigned int flags)
> {
> @@ -6901,9 +6915,16 @@ static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
> if (!qf_inums[type])
> return -EPERM;
>
> + if (!ext4_check_quota_inum(type, qf_inums[type])) {
> + ext4_error(sb, "Bad quota inum: %lu, type: %d",
> + qf_inums[type], type);
> + return -EUCLEAN;
> + }
> +
> qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
> if (IS_ERR(qf_inode)) {
> - ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
> + ext4_error(sb, "Bad quota inode: %lu, type: %d",
> + qf_inums[type], type);
> return PTR_ERR(qf_inode);
> }
>
> @@ -6942,8 +6963,9 @@ int ext4_enable_quotas(struct super_block *sb)
> if (err) {
> ext4_warning(sb,
> "Failed to enable quota tracking "
> - "(type=%d, err=%d). Please run "
> - "e2fsck to fix.", type, err);
> + "(type=%d, err=%d, ino=%lu). "
> + "Please run e2fsck to fix.", type,
> + err, qf_inums[type]);
> for (type--; type >= 0; type--) {
> struct inode *inode;
>
> --
> 2.31.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR