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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/xattr.c
parentfa0d2b9bd717340e0bc4850a80ac0eb344e9a7fb (diff)
downloadlinux-b83cc9693f39689490970c19f6c5b866f6719a70.tar.bz2
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/xattr.c')
-rw-r--r--fs/btrfs/xattr.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 698fdd2c739c..a5776531dc2b 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -316,6 +316,15 @@ ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags)
{
+ struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
+
+ /*
+ * The permission on security.* and system.* is not checked
+ * in permission().
+ */
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+
/*
* If this is a request for a synthetic attribute in the system.*
* namespace use the generic infrastructure to resolve a handler
@@ -336,6 +345,15 @@ int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
int btrfs_removexattr(struct dentry *dentry, const char *name)
{
+ struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
+
+ /*
+ * The permission on security.* and system.* is not checked
+ * in permission().
+ */
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+
/*
* If this is a request for a synthetic attribute in the system.*
* namespace use the generic infrastructure to resolve a handler