| Message ID | 1351766770-4044-4-git-send-email-Anand.Jain@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Anand, Some comments on your kernel patch from a quick jump through: On 01.11.2012 11:46, Anand jain wrote: > From: Anand Jain <anand.jain@oracle.com> > > This modifies the struct btrfs_root_item to hold the label, > and make it v3 of this structure. > > Signed-off-by: Anand Jain <anand.jain@oracle.com> > --- > fs/btrfs/ctree.h | 14 ++++++++++++++ > fs/btrfs/ioctl.c | 32 ++++++++++++++++++++++++++++++++ > fs/btrfs/ioctl.h | 2 ++ > fs/btrfs/root-tree.c | 44 +++++++++++++++++++++++--------------------- > fs/btrfs/transaction.c | 1 + > 5 files changed, 72 insertions(+), 21 deletions(-) > > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > index 994d255..b280256 100644 > --- a/fs/btrfs/ctree.h > +++ b/fs/btrfs/ctree.h > @@ -759,6 +759,10 @@ struct btrfs_root_item { > struct btrfs_timespec otime; > struct btrfs_timespec stime; > struct btrfs_timespec rtime; > + > + __le64 generation_v3; What is that supposed to be? > + char label[BTRFS_LABEL_SIZE]; /* Add label to subvol */ > + > __le64 reserved[8]; /* for future */ > } __attribute__ ((__packed__)); You can't do that. There's a reason why we've got reserved bytes for future use. Never change the struct's size. > @@ -2428,6 +2432,8 @@ BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item, > last_snapshot, 64); > BTRFS_SETGET_STACK_FUNCS(root_generation_v2, struct btrfs_root_item, > generation_v2, 64); > +BTRFS_SETGET_STACK_FUNCS(root_generation_v3, struct btrfs_root_item, > + generation_v3, 64); > BTRFS_SETGET_STACK_FUNCS(root_ctransid, struct btrfs_root_item, > ctransid, 64); > BTRFS_SETGET_STACK_FUNCS(root_otransid, struct btrfs_root_item, > @@ -2441,6 +2447,14 @@ static inline bool btrfs_root_readonly(struct btrfs_root *root) > { > return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0; > } > +static inline char * btrfs_root_label(struct btrfs_root *root) > +{ > + return (root->root_item.label); > +} > +static inline void btrfs_root_set_label(struct btrfs_root *root, char *val) > +{ > + memcpy(root->root_item.label,val,BTRFS_LABEL_SIZE); > +} > > /* struct btrfs_root_backup */ > BTRFS_SETGET_STACK_FUNCS(backup_tree_root, struct btrfs_root_backup, > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index e58bd9d..cce0128 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -3725,6 +3725,34 @@ static int btrfs_ioctl_set_label(struct btrfs_root *root, void __user *arg) > return 0; > } > > +static int btrfs_ioctl_subvol_getlabel(struct btrfs_root *root, > + void __user *arg) > +{ > + char *label; > + > + label = btrfs_root_label(root); > + if (copy_to_user(arg, label, BTRFS_LABEL_SIZE)) > + return -EFAULT; > + return 0; > +} > + > +static int btrfs_ioctl_subvol_setlabel(struct btrfs_root *root, > + void __user *arg) > +{ > + char label[BTRFS_LABEL_SIZE]; > + struct btrfs_trans_handle *trans; > + > + if (copy_from_user(label, arg, BTRFS_LABEL_SIZE)) > + return -EFAULT; > + trans = btrfs_start_transaction(root, 1); > + if (IS_ERR(trans)) > + return PTR_ERR(trans); > + btrfs_root_set_label(root, label); > + btrfs_commit_transaction(trans, root); Why use start/commit instead of join/end here? > + return 0; > +} > + > long btrfs_ioctl(struct file *file, unsigned int > cmd, unsigned long arg) > { > @@ -3827,6 +3855,10 @@ long btrfs_ioctl(struct file *file, unsigned int > return btrfs_ioctl_get_label(root, argp); > case BTRFS_IOC_SET_LABEL: > return btrfs_ioctl_set_label(root, argp); > + case BTRFS_IOC_SUBVOL_GETLABEL: > + return btrfs_ioctl_subvol_getlabel(root, argp); > + case BTRFS_IOC_SUBVOL_SETLABEL: > + return btrfs_ioctl_subvol_setlabel(root, argp); > } > > return -ENOTTY; > diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h > index 0c60fcb..1009a0c 100644 > --- a/fs/btrfs/ioctl.h > +++ b/fs/btrfs/ioctl.h > @@ -455,4 +455,6 @@ struct btrfs_ioctl_send_args { > struct btrfs_ioctl_get_dev_stats) > #define BTRFS_IOC_GET_LABEL _IOR(BTRFS_IOCTL_MAGIC, 53, __u64) > #define BTRFS_IOC_SET_LABEL _IOW(BTRFS_IOCTL_MAGIC, 54, __u64) > +#define BTRFS_IOC_SUBVOL_GETLABEL _IOWR(BTRFS_IOCTL_MAGIC, 55, __u64) > +#define BTRFS_IOC_SUBVOL_SETLABEL _IOW(BTRFS_IOCTL_MAGIC, 56, __u64) > #endif > diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c > index eb923d0..2a9ae5f 100644 > --- a/fs/btrfs/root-tree.c > +++ b/fs/btrfs/root-tree.c > @@ -35,32 +35,34 @@ void btrfs_read_root_item(struct btrfs_root *root, > { > uuid_le uuid; > int len; > - int need_reset = 0; > > len = btrfs_item_size_nr(eb, slot); > read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot), > min_t(int, len, (int)sizeof(*item))); > - if (len < sizeof(*item)) > - need_reset = 1; > - if (!need_reset && btrfs_root_generation(item) > - != btrfs_root_generation_v2(item)) { > - if (btrfs_root_generation_v2(item) != 0) { > - printk(KERN_WARNING "btrfs: mismatching " > - "generation and generation_v2 " > - "found in root item. This root " > - "was probably mounted with an " > - "older kernel. Resetting all " > - "new fields.\n"); Please argue why removing this without replacement should be a good idea. > - } > - need_reset = 1; > - } > - if (need_reset) { > - memset(&item->generation_v2, 0, > - sizeof(*item) - offsetof(struct btrfs_root_item, > - generation_v2)); > > - uuid_le_gen(&uuid); > - memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE); > + /* when len is gt sizeof(*item) that means its downgrade and > + the new members won't be touched anyways > + if len is lt sizeof(*item) its upgrade, we need to take > + care to set/reset newer members. > + */ > + if (len < sizeof(*item)) { > + /* there is an upgrade need to set/reset the new members > + assume v1 v2 v3 it can be upgrade from > + v1 to v2 (set/reset only new members of v2) > + v2 to v3 (set/reset only new members of v3) > + v1 to v3 (set/reset new to v1) > + */ > + if (btrfs_root_generation(item) != btrfs_root_generation_v2(item)) { > + //memset(&item->generation_v2, 0, > + //sizeof(*item) - offsetof(struct btrfs_root_item, generation_v2)); > + memset(&item->generation_v2, 0, sizeof(*item) - len); > + uuid_le_gen(&uuid); > + memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE); > + } else if (btrfs_root_generation_v2(item) != btrfs_root_generation_v3(item)) { > + //memset(&item->generation_v3, 0, > + // sizeof(*item) - offsetof(struct btrfs_root_item, generation_v3)); > + memset(&item->generation_v3, 0, sizeof(*item) - len); > + } > } > } > > diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c > index 04bbfb1..45bff43 100644 > --- a/fs/btrfs/transaction.c > +++ b/fs/btrfs/transaction.c > @@ -1116,6 +1116,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, > btrfs_set_root_otransid(new_root_item, trans->transid); > memset(&new_root_item->stime, 0, sizeof(new_root_item->stime)); > memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime)); > + memset(new_root_item->label, 0, BTRFS_LABEL_SIZE); > btrfs_set_root_stransid(new_root_item, 0); > btrfs_set_root_rtransid(new_root_item, 0); > > -Jan -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Jan, Thanks for the review. Just posted the v2 patch for the btrfs kernel patch. Which, used the btrfs_root_item reserved space and used join_transaction -Anand On 05/11/12 15:39, Jan Schmidt wrote: > Hi Anand, > > Some comments on your kernel patch from a quick jump through: > > On 01.11.2012 11:46, Anand jain wrote: >> From: Anand Jain <anand.jain@oracle.com> >> >> This modifies the struct btrfs_root_item to hold the label, >> and make it v3 of this structure. >> >> Signed-off-by: Anand Jain <anand.jain@oracle.com> >> --- >> fs/btrfs/ctree.h | 14 ++++++++++++++ >> fs/btrfs/ioctl.c | 32 ++++++++++++++++++++++++++++++++ >> fs/btrfs/ioctl.h | 2 ++ >> fs/btrfs/root-tree.c | 44 +++++++++++++++++++++++--------------------- >> fs/btrfs/transaction.c | 1 + >> 5 files changed, 72 insertions(+), 21 deletions(-) >> >> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h >> index 994d255..b280256 100644 >> --- a/fs/btrfs/ctree.h >> +++ b/fs/btrfs/ctree.h >> @@ -759,6 +759,10 @@ struct btrfs_root_item { >> struct btrfs_timespec otime; >> struct btrfs_timespec stime; >> struct btrfs_timespec rtime; >> + >> + __le64 generation_v3; > > What is that supposed to be? > >> + char label[BTRFS_LABEL_SIZE]; /* Add label to subvol */ >> + >> __le64 reserved[8]; /* for future */ >> } __attribute__ ((__packed__)); > > You can't do that. There's a reason why we've got reserved bytes for > future use. Never change the struct's size. > >> @@ -2428,6 +2432,8 @@ BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item, >> last_snapshot, 64); >> BTRFS_SETGET_STACK_FUNCS(root_generation_v2, struct btrfs_root_item, >> generation_v2, 64); >> +BTRFS_SETGET_STACK_FUNCS(root_generation_v3, struct btrfs_root_item, >> + generation_v3, 64); >> BTRFS_SETGET_STACK_FUNCS(root_ctransid, struct btrfs_root_item, >> ctransid, 64); >> BTRFS_SETGET_STACK_FUNCS(root_otransid, struct btrfs_root_item, >> @@ -2441,6 +2447,14 @@ static inline bool btrfs_root_readonly(struct btrfs_root *root) >> { >> return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0; >> } >> +static inline char * btrfs_root_label(struct btrfs_root *root) >> +{ >> + return (root->root_item.label); >> +} >> +static inline void btrfs_root_set_label(struct btrfs_root *root, char *val) >> +{ >> + memcpy(root->root_item.label,val,BTRFS_LABEL_SIZE); >> +} >> >> /* struct btrfs_root_backup */ >> BTRFS_SETGET_STACK_FUNCS(backup_tree_root, struct btrfs_root_backup, >> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c >> index e58bd9d..cce0128 100644 >> --- a/fs/btrfs/ioctl.c >> +++ b/fs/btrfs/ioctl.c >> @@ -3725,6 +3725,34 @@ static int btrfs_ioctl_set_label(struct btrfs_root *root, void __user *arg) >> return 0; >> } >> >> +static int btrfs_ioctl_subvol_getlabel(struct btrfs_root *root, >> + void __user *arg) >> +{ >> + char *label; >> + >> + label = btrfs_root_label(root); >> + if (copy_to_user(arg, label, BTRFS_LABEL_SIZE)) >> + return -EFAULT; >> + return 0; >> +} >> + >> +static int btrfs_ioctl_subvol_setlabel(struct btrfs_root *root, >> + void __user *arg) >> +{ >> + char label[BTRFS_LABEL_SIZE]; >> + struct btrfs_trans_handle *trans; >> + >> + if (copy_from_user(label, arg, BTRFS_LABEL_SIZE)) >> + return -EFAULT; >> + trans = btrfs_start_transaction(root, 1); >> + if (IS_ERR(trans)) >> + return PTR_ERR(trans); >> + btrfs_root_set_label(root, label); >> + btrfs_commit_transaction(trans, root); > > Why use start/commit instead of join/end here? > >> + return 0; >> +} >> + >> long btrfs_ioctl(struct file *file, unsigned int >> cmd, unsigned long arg) >> { >> @@ -3827,6 +3855,10 @@ long btrfs_ioctl(struct file *file, unsigned int >> return btrfs_ioctl_get_label(root, argp); >> case BTRFS_IOC_SET_LABEL: >> return btrfs_ioctl_set_label(root, argp); >> + case BTRFS_IOC_SUBVOL_GETLABEL: >> + return btrfs_ioctl_subvol_getlabel(root, argp); >> + case BTRFS_IOC_SUBVOL_SETLABEL: >> + return btrfs_ioctl_subvol_setlabel(root, argp); >> } >> >> return -ENOTTY; >> diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h >> index 0c60fcb..1009a0c 100644 >> --- a/fs/btrfs/ioctl.h >> +++ b/fs/btrfs/ioctl.h >> @@ -455,4 +455,6 @@ struct btrfs_ioctl_send_args { >> struct btrfs_ioctl_get_dev_stats) >> #define BTRFS_IOC_GET_LABEL _IOR(BTRFS_IOCTL_MAGIC, 53, __u64) >> #define BTRFS_IOC_SET_LABEL _IOW(BTRFS_IOCTL_MAGIC, 54, __u64) >> +#define BTRFS_IOC_SUBVOL_GETLABEL _IOWR(BTRFS_IOCTL_MAGIC, 55, __u64) >> +#define BTRFS_IOC_SUBVOL_SETLABEL _IOW(BTRFS_IOCTL_MAGIC, 56, __u64) >> #endif >> diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c >> index eb923d0..2a9ae5f 100644 >> --- a/fs/btrfs/root-tree.c >> +++ b/fs/btrfs/root-tree.c >> @@ -35,32 +35,34 @@ void btrfs_read_root_item(struct btrfs_root *root, >> { >> uuid_le uuid; >> int len; >> - int need_reset = 0; >> >> len = btrfs_item_size_nr(eb, slot); >> read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot), >> min_t(int, len, (int)sizeof(*item))); >> - if (len < sizeof(*item)) >> - need_reset = 1; >> - if (!need_reset && btrfs_root_generation(item) >> - != btrfs_root_generation_v2(item)) { >> - if (btrfs_root_generation_v2(item) != 0) { >> - printk(KERN_WARNING "btrfs: mismatching " >> - "generation and generation_v2 " >> - "found in root item. This root " >> - "was probably mounted with an " >> - "older kernel. Resetting all " >> - "new fields.\n"); > > Please argue why removing this without replacement should be a good idea. > >> - } >> - need_reset = 1; >> - } >> - if (need_reset) { >> - memset(&item->generation_v2, 0, >> - sizeof(*item) - offsetof(struct btrfs_root_item, >> - generation_v2)); >> >> - uuid_le_gen(&uuid); >> - memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE); >> + /* when len is gt sizeof(*item) that means its downgrade and >> + the new members won't be touched anyways >> + if len is lt sizeof(*item) its upgrade, we need to take >> + care to set/reset newer members. >> + */ >> + if (len < sizeof(*item)) { >> + /* there is an upgrade need to set/reset the new members >> + assume v1 v2 v3 it can be upgrade from >> + v1 to v2 (set/reset only new members of v2) >> + v2 to v3 (set/reset only new members of v3) >> + v1 to v3 (set/reset new to v1) >> + */ >> + if (btrfs_root_generation(item) != btrfs_root_generation_v2(item)) { >> + //memset(&item->generation_v2, 0, >> + //sizeof(*item) - offsetof(struct btrfs_root_item, generation_v2)); >> + memset(&item->generation_v2, 0, sizeof(*item) - len); >> + uuid_le_gen(&uuid); >> + memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE); >> + } else if (btrfs_root_generation_v2(item) != btrfs_root_generation_v3(item)) { >> + //memset(&item->generation_v3, 0, >> + // sizeof(*item) - offsetof(struct btrfs_root_item, generation_v3)); >> + memset(&item->generation_v3, 0, sizeof(*item) - len); >> + } >> } >> } >> >> diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c >> index 04bbfb1..45bff43 100644 >> --- a/fs/btrfs/transaction.c >> +++ b/fs/btrfs/transaction.c >> @@ -1116,6 +1116,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, >> btrfs_set_root_otransid(new_root_item, trans->transid); >> memset(&new_root_item->stime, 0, sizeof(new_root_item->stime)); >> memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime)); >> + memset(new_root_item->label, 0, BTRFS_LABEL_SIZE); >> btrfs_set_root_stransid(new_root_item, 0); >> btrfs_set_root_rtransid(new_root_item, 0); >> >> > > -Jan > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 994d255..b280256 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -759,6 +759,10 @@ struct btrfs_root_item { struct btrfs_timespec otime; struct btrfs_timespec stime; struct btrfs_timespec rtime; + + __le64 generation_v3; + char label[BTRFS_LABEL_SIZE]; /* Add label to subvol */ + __le64 reserved[8]; /* for future */ } __attribute__ ((__packed__)); @@ -2428,6 +2432,8 @@ BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item, last_snapshot, 64); BTRFS_SETGET_STACK_FUNCS(root_generation_v2, struct btrfs_root_item, generation_v2, 64); +BTRFS_SETGET_STACK_FUNCS(root_generation_v3, struct btrfs_root_item, + generation_v3, 64); BTRFS_SETGET_STACK_FUNCS(root_ctransid, struct btrfs_root_item, ctransid, 64); BTRFS_SETGET_STACK_FUNCS(root_otransid, struct btrfs_root_item, @@ -2441,6 +2447,14 @@ static inline bool btrfs_root_readonly(struct btrfs_root *root) { return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0; } +static inline char * btrfs_root_label(struct btrfs_root *root) +{ + return (root->root_item.label); +} +static inline void btrfs_root_set_label(struct btrfs_root *root, char *val) +{ + memcpy(root->root_item.label,val,BTRFS_LABEL_SIZE); +} /* struct btrfs_root_backup */ BTRFS_SETGET_STACK_FUNCS(backup_tree_root, struct btrfs_root_backup, diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index e58bd9d..cce0128 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3725,6 +3725,34 @@ static int btrfs_ioctl_set_label(struct btrfs_root *root, void __user *arg) return 0; } +static int btrfs_ioctl_subvol_getlabel(struct btrfs_root *root, + void __user *arg) +{ + char *label; + + label = btrfs_root_label(root); + if (copy_to_user(arg, label, BTRFS_LABEL_SIZE)) + return -EFAULT; + return 0; +} + +static int btrfs_ioctl_subvol_setlabel(struct btrfs_root *root, + void __user *arg) +{ + char label[BTRFS_LABEL_SIZE]; + struct btrfs_trans_handle *trans; + + if (copy_from_user(label, arg, BTRFS_LABEL_SIZE)) + return -EFAULT; + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) + return PTR_ERR(trans); + btrfs_root_set_label(root, label); + btrfs_commit_transaction(trans, root); + + return 0; +} + long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -3827,6 +3855,10 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_get_label(root, argp); case BTRFS_IOC_SET_LABEL: return btrfs_ioctl_set_label(root, argp); + case BTRFS_IOC_SUBVOL_GETLABEL: + return btrfs_ioctl_subvol_getlabel(root, argp); + case BTRFS_IOC_SUBVOL_SETLABEL: + return btrfs_ioctl_subvol_setlabel(root, argp); } return -ENOTTY; diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 0c60fcb..1009a0c 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -455,4 +455,6 @@ struct btrfs_ioctl_send_args { struct btrfs_ioctl_get_dev_stats) #define BTRFS_IOC_GET_LABEL _IOR(BTRFS_IOCTL_MAGIC, 53, __u64) #define BTRFS_IOC_SET_LABEL _IOW(BTRFS_IOCTL_MAGIC, 54, __u64) +#define BTRFS_IOC_SUBVOL_GETLABEL _IOWR(BTRFS_IOCTL_MAGIC, 55, __u64) +#define BTRFS_IOC_SUBVOL_SETLABEL _IOW(BTRFS_IOCTL_MAGIC, 56, __u64) #endif diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index eb923d0..2a9ae5f 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -35,32 +35,34 @@ void btrfs_read_root_item(struct btrfs_root *root, { uuid_le uuid; int len; - int need_reset = 0; len = btrfs_item_size_nr(eb, slot); read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot), min_t(int, len, (int)sizeof(*item))); - if (len < sizeof(*item)) - need_reset = 1; - if (!need_reset && btrfs_root_generation(item) - != btrfs_root_generation_v2(item)) { - if (btrfs_root_generation_v2(item) != 0) { - printk(KERN_WARNING "btrfs: mismatching " - "generation and generation_v2 " - "found in root item. This root " - "was probably mounted with an " - "older kernel. Resetting all " - "new fields.\n"); - } - need_reset = 1; - } - if (need_reset) { - memset(&item->generation_v2, 0, - sizeof(*item) - offsetof(struct btrfs_root_item, - generation_v2)); - uuid_le_gen(&uuid); - memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE); + /* when len is gt sizeof(*item) that means its downgrade and + the new members won't be touched anyways + if len is lt sizeof(*item) its upgrade, we need to take + care to set/reset newer members. + */ + if (len < sizeof(*item)) { + /* there is an upgrade need to set/reset the new members + assume v1 v2 v3 it can be upgrade from + v1 to v2 (set/reset only new members of v2) + v2 to v3 (set/reset only new members of v3) + v1 to v3 (set/reset new to v1) + */ + if (btrfs_root_generation(item) != btrfs_root_generation_v2(item)) { + //memset(&item->generation_v2, 0, + //sizeof(*item) - offsetof(struct btrfs_root_item, generation_v2)); + memset(&item->generation_v2, 0, sizeof(*item) - len); + uuid_le_gen(&uuid); + memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE); + } else if (btrfs_root_generation_v2(item) != btrfs_root_generation_v3(item)) { + //memset(&item->generation_v3, 0, + // sizeof(*item) - offsetof(struct btrfs_root_item, generation_v3)); + memset(&item->generation_v3, 0, sizeof(*item) - len); + } } } diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 04bbfb1..45bff43 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1116,6 +1116,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, btrfs_set_root_otransid(new_root_item, trans->transid); memset(&new_root_item->stime, 0, sizeof(new_root_item->stime)); memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime)); + memset(new_root_item->label, 0, BTRFS_LABEL_SIZE); btrfs_set_root_stransid(new_root_item, 0); btrfs_set_root_rtransid(new_root_item, 0);