• Li Zefan's avatar
    Btrfs: Add readonly snapshots support · b83cc969
    Li Zefan authored
    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: default avatarLi Zefan <lizf@cn.fujitsu.com>
    b83cc969
ctree.h 82.5 KB