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authorLi Zefan <lizf@cn.fujitsu.com>2010-12-20 16:04:08 +0800
committerLi Zefan <lizf@cn.fujitsu.com>2010-12-23 08:49:17 +0800
commitb83cc9693f39689490970c19f6c5b866f6719a70 (patch)
treeb86d09884015fce195a4ac5ff1e8ec5f6ec00677 /fs/btrfs/ctree.h
parentfa0d2b9bd717340e0bc4850a80ac0eb344e9a7fb (diff)
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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/ctree.h')
-rw-r--r--fs/btrfs/ctree.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index af52f6d..4403e56 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -597,6 +597,8 @@ struct btrfs_dir_item {
u8 type;
} __attribute__ ((__packed__));
+#define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)
+
struct btrfs_root_item {
struct btrfs_inode_item inode;
__le64 generation;
@@ -1893,6 +1895,11 @@ BTRFS_SETGET_STACK_FUNCS(root_limit, struct btrfs_root_item, byte_limit, 64);
BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item,
last_snapshot, 64);
+static inline bool btrfs_root_readonly(struct btrfs_root *root)
+{
+ return root->root_item.flags & BTRFS_ROOT_SUBVOL_RDONLY;
+}
+
/* struct btrfs_super_block */
BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64);