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| author | Li Zefan <lizf@cn.fujitsu.com> | 2010-12-20 16:04:08 +0800 |
|---|---|---|
| committer | Li Zefan <lizf@cn.fujitsu.com> | 2010-12-23 08:49:17 +0800 |
| commit | b83cc9693f39689490970c19f6c5b866f6719a70 (patch) | |
| tree | b86d09884015fce195a4ac5ff1e8ec5f6ec00677 /fs/btrfs/transaction.c | |
| parent | fa0d2b9bd717340e0bc4850a80ac0eb344e9a7fb (diff) | |
| download | lwn-b83cc9693f39689490970c19f6c5b866f6719a70.tar.gz lwn-b83cc9693f39689490970c19f6c5b866f6719a70.zip | |
Btrfs: Add readonly snapshots support
Usage:
Set BTRFS_SUBVOL_RDONLY of btrfs_ioctl_vol_arg_v2->flags, and call
ioctl(BTRFS_I0CTL_SNAP_CREATE_V2).
Implementation:
- Set readonly bit of btrfs_root_item->flags.
- Add readonly checks in btrfs_permission (inode_permission),
btrfs_setattr, btrfs_set/remove_xattr and some ioctls.
Changelog for v3:
- Eliminate btrfs_root->readonly, but check btrfs_root->root_item.flags.
- Rename BTRFS_ROOT_SNAP_RDONLY to BTRFS_ROOT_SUBVOL_RDONLY.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Diffstat (limited to 'fs/btrfs/transaction.c')
| -rw-r--r-- | fs/btrfs/transaction.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index f50e931fc217..29e30d832ec9 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -910,6 +910,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, u64 to_reserve = 0; u64 index = 0; u64 objectid; + u64 root_flags; new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS); if (!new_root_item) { @@ -967,6 +968,13 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, btrfs_set_root_last_snapshot(&root->root_item, trans->transid); memcpy(new_root_item, &root->root_item, sizeof(*new_root_item)); + root_flags = btrfs_root_flags(new_root_item); + if (pending->readonly) + root_flags |= BTRFS_ROOT_SUBVOL_RDONLY; + else + root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY; + btrfs_set_root_flags(new_root_item, root_flags); + old = btrfs_lock_root_node(root); btrfs_cow_block(trans, root, old, NULL, 0, &old); btrfs_set_lock_blocking(old); |