| Message ID | 20211019064959.625557-3-yebin10@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | Fix some issues about mmp | expand |
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@huawei.com> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> 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 >
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. "
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@huawei.com> --- fs/ext4/ext4.h | 5 ++++- fs/ext4/mmp.c | 9 +++++---- 2 files changed, 9 insertions(+), 5 deletions(-)