From: Anand Jain <anand.j...@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.j...@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; + 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); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html