ceph: remove xattr when null value is given to setxattr()

For the setxattr request, introduce a new flag CEPH_XATTR_REMOVE
to distinguish null value case from the zero-length value case.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 28f9793b9167791735e780f81518d92a529b00f0..231c02b16c0c7ac3d3c24e225a408875b1cf98d2 100644 (file)
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -12,6 +12,9 @@
 #define XATTR_CEPH_PREFIX "ceph."
 #define XATTR_CEPH_PREFIX_LEN (sizeof (XATTR_CEPH_PREFIX) - 1)
 
+static int __remove_xattr(struct ceph_inode_info *ci,
+                         struct ceph_inode_xattr *xattr);
+
 /*
  * List of handlers for synthetic system.* attributes. Other
  * attributes are handled directly.
@@ -359,6 +362,12 @@ static int __set_xattr(struct ceph_inode_info *ci,
                        kfree(val);
                        return err;
                }
+               if (update_xattr < 0) {
+                       if (xattr)
+                               __remove_xattr(ci, xattr);
+                       kfree(name);
+                       return 0;
+               }
        }
 
        if (!xattr) {
@@ -862,6 +871,9 @@ static int ceph_sync_setxattr(struct dentry *dentry, const char *name,
 
        dout("setxattr value=%.*s\n", (int)size, value);
 
+       if (!value)
+               flags |= CEPH_XATTR_REMOVE;
+
        /* do request */
        req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETXATTR,
                                       USE_AUTH_MDS);
@@ -965,8 +977,8 @@ retry:
                goto retry;
        }
 
-       err = __set_xattr(ci, newname, name_len, newval,
-                         val_len, flags, 1, &xattr);
+       err = __set_xattr(ci, newname, name_len, newval, val_len,
+                         flags, value ? 1 : -1, &xattr);
 
        if (!err) {
                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL);

diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index 2623cffc73a17b32cf9660bf67cf05bd9ae4b45f..25bfb0eff7720b459ffefa45ec035ec0229c8b1c 100644 (file)
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -373,8 +373,9 @@ extern const char *ceph_mds_op_name(int op);
 /*
  * Ceph setxattr request flags.
  */
-#define CEPH_XATTR_CREATE  1
-#define CEPH_XATTR_REPLACE 2
+#define CEPH_XATTR_CREATE  (1 << 0)
+#define CEPH_XATTR_REPLACE (1 << 1)
+#define CEPH_XATTR_REMOVE  (1 << 31)
 
 union ceph_mds_request_args {
        struct {