On Tue 19-10-21 14:49:56, Ye Bin wrote:
> As mmp and check_mmp is point to the same data, so there will never
> detect conflict.
> To solve this issue just compare to local data.
>
> Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 404dd50856e5..9a487a558787 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2601,6 +2601,8 @@ struct ext4_features {
> #define EXT4_MMP_SEQ_FSCK 0xE24D4D50U /* mmp_seq value when being fscked */
> #define EXT4_MMP_SEQ_MAX 0xE24D4D4FU /* maximum valid mmp_seq value */
>
> +#define EXT4_MMP_NODENAME_LEN 64 /* mmp_nodename length */
> +
> struct mmp_struct {
> __le32 mmp_magic; /* Magic number for MMP */
> __le32 mmp_seq; /* Sequence no. updated periodically */
> @@ -2610,7 +2612,8 @@ struct mmp_struct {
> * purposes and do not affect the correctness of the algorithm
> */
> __le64 mmp_time; /* Time last updated */
> - char mmp_nodename[64]; /* Node which last updated MMP block */
> + /* Node which last updated MMP block */
> + char mmp_nodename[EXT4_MMP_NODENAME_LEN];
> char mmp_bdevname[32]; /* Bdev which last updated MMP block */
>
> /*
> diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
> index 11627ff002d3..4af8b99ade84 100644
> --- a/fs/ext4/mmp.c
> +++ b/fs/ext4/mmp.c
> @@ -138,6 +138,7 @@ static int kmmpd(void *data)
> unsigned mmp_check_interval;
> unsigned long last_update_time;
> unsigned long diff;
> + char nodename[EXT4_MMP_NODENAME_LEN];
> int retval = 0;
>
> mmp_block = le64_to_cpu(es->s_mmp_block);
> @@ -154,8 +155,8 @@ static int kmmpd(void *data)
> BUILD_BUG_ON(sizeof(mmp->mmp_bdevname) < BDEVNAME_SIZE);
> bdevname(bh->b_bdev, mmp->mmp_bdevname);
>
> - memcpy(mmp->mmp_nodename, init_utsname()->nodename,
> - sizeof(mmp->mmp_nodename));
> + memcpy(nodename, init_utsname()->nodename, sizeof(nodename));
> + memcpy(mmp->mmp_nodename, nodename, sizeof(mmp->mmp_nodename));
>
> while (!kthread_should_stop() && !sb_rdonly(sb)) {
> if (!ext4_has_feature_mmp(sb)) {
> @@ -207,8 +208,8 @@ static int kmmpd(void *data)
> }
>
> mmp_check = (struct mmp_struct *)(bh_check->b_data);
> - if (mmp->mmp_seq != mmp_check->mmp_seq ||
> - memcmp(mmp->mmp_nodename, mmp_check->mmp_nodename,
> + if (seq != mmp_check->mmp_seq ||
> + memcmp(nodename, mmp_check->mmp_nodename,
> sizeof(mmp->mmp_nodename))) {
> dump_mmp_msg(sb, mmp_check,
> "Error while updating MMP info. "
> --
> 2.31.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
