ceph: fix getxattr vxattr handling

Change the vxattr handling for getxattr so that vxattrs are checked
prior to any xattr content, and never after.  Enforce vxattr existence
via the exists_cb callback.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Sam Lang <sam.lang@inktank.com>

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 06344da4e9687607e5357d78d22dcb506015cf8e..87b85f3403d4d8411c1328599a6a6760d9d59c4f 100644 (file)
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -569,13 +569,17 @@ ssize_t ceph_getxattr(struct dentry *dentry, const char *name, void *value,
        if (!ceph_is_valid_xattr(name))
                return -ENODATA;
 
-       /* let's see if a virtual xattr was requested */
-       vxattr = ceph_match_vxattr(inode, name);
-
        spin_lock(&ci->i_ceph_lock);
        dout("getxattr %p ver=%lld index_ver=%lld\n", inode,
             ci->i_xattrs.version, ci->i_xattrs.index_version);
 
+       /* let's see if a virtual xattr was requested */
+       vxattr = ceph_match_vxattr(inode, name);
+       if (vxattr && !(vxattr->exists_cb && !vxattr->exists_cb(ci))) {
+               err = vxattr->getxattr_cb(ci, value, size);
+               goto out;
+       }
+
        if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1) &&
            (ci->i_xattrs.index_version >= ci->i_xattrs.version)) {
                goto get_xattr;
@@ -589,11 +593,6 @@ ssize_t ceph_getxattr(struct dentry *dentry, const char *name, void *value,
 
        spin_lock(&ci->i_ceph_lock);
 
-       if (vxattr && vxattr->readonly) {
-               err = vxattr->getxattr_cb(ci, value, size);
-               goto out;
-       }
-
        err = __build_xattrs(inode);
        if (err < 0)
                goto out;
@@ -601,11 +600,8 @@ ssize_t ceph_getxattr(struct dentry *dentry, const char *name, void *value,
 get_xattr:
        err = -ENODATA;  /* == ENOATTR */
        xattr = __get_xattr(ci, name);
-       if (!xattr) {
-               if (vxattr)
-                       err = vxattr->getxattr_cb(ci, value, size);
+       if (!xattr)
                goto out;
-       }
 
        err = -ERANGE;
        if (size && size < xattr->val_len)