1 files changed, 57 insertions, 28 deletions

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 35dae6d5493a..f85355bf49c4 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -2266,43 +2266,72 @@ int ceph_permission(struct inode *inode, int mask)
         return err;
 }
 
+/* Craft a mask of needed caps given a set of requested statx attrs. */
+static int statx_to_caps(u32 want)
+{
+        int mask = 0;
+
+        if (want & (STATX_MODE|STATX_UID|STATX_GID|STATX_CTIME))
+                mask |= CEPH_CAP_AUTH_SHARED;
+
+        if (want & (STATX_NLINK|STATX_CTIME))
+                mask |= CEPH_CAP_LINK_SHARED;
+
+        if (want & (STATX_ATIME|STATX_MTIME|STATX_CTIME|STATX_SIZE|
+                    STATX_BLOCKS))
+                mask |= CEPH_CAP_FILE_SHARED;
+
+        if (want & (STATX_CTIME))
+                mask |= CEPH_CAP_XATTR_SHARED;
+
+        return mask;
+}
+
 /*
- * Get all attributes.  Hopefully somedata we'll have a statlite()
- * and can limit the fields we require to be accurate.
+ * Get all the attributes. If we have sufficient caps for the requested attrs,
+ * then we can avoid talking to the MDS at all.
  */
 int ceph_getattr(const struct path *path, struct kstat *stat,
                  u32 request_mask, unsigned int flags)
 {
         struct inode *inode = d_inode(path->dentry);
         struct ceph_inode_info *ci = ceph_inode(inode);
-        int err;
+        int err = 0;
 
-        err = ceph_do_getattr(inode, CEPH_STAT_CAP_INODE_ALL, false);
-        if (!err) {
-                generic_fillattr(inode, stat);
-                stat->ino = ceph_translate_ino(inode->i_sb, inode->i_ino);
-                if (ceph_snap(inode) == CEPH_NOSNAP)
-                        stat->dev = inode->i_sb->s_dev;
+        /* Skip the getattr altogether if we're asked not to sync */
+        if (!(flags & AT_STATX_DONT_SYNC)) {
+                err = ceph_do_getattr(inode, statx_to_caps(request_mask),
+                                      flags & AT_STATX_FORCE_SYNC);
+                if (err)
+                        return err;
+        }
+
+        generic_fillattr(inode, stat);
+        stat->ino = ceph_translate_ino(inode->i_sb, inode->i_ino);
+        if (ceph_snap(inode) == CEPH_NOSNAP)
+                stat->dev = inode->i_sb->s_dev;
+        else
+                stat->dev = ci->i_snapid_map ? ci->i_snapid_map->dev : 0;
+
+        if (S_ISDIR(inode->i_mode)) {
+                if (ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb),
+                                        RBYTES))
+                        stat->size = ci->i_rbytes;
                 else
-                        stat->dev = ci->i_snapid_map ? ci->i_snapid_map->dev : 0;
-
-                if (S_ISDIR(inode->i_mode)) {
-                        if (ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb),
-                                                RBYTES))
-                                stat->size = ci->i_rbytes;
-                        else
-                                stat->size = ci->i_files + ci->i_subdirs;
-                        stat->blocks = 0;
-                        stat->blksize = 65536;
-                        /*
-                         * Some applications rely on the number of st_nlink
-                         * value on directories to be either 0 (if unlinked)
-                         * or 2 + number of subdirectories.
-                         */
-                        if (stat->nlink == 1)
-                                /* '.' + '..' + subdirs */
-                                stat->nlink = 1 + 1 + ci->i_subdirs;
-                }
+                        stat->size = ci->i_files + ci->i_subdirs;
+                stat->blocks = 0;
+                stat->blksize = 65536;
+                /*
+                 * Some applications rely on the number of st_nlink
+                 * value on directories to be either 0 (if unlinked)
+                 * or 2 + number of subdirectories.
+                 */
+                if (stat->nlink == 1)
+                        /* '.' + '..' + subdirs */
+                        stat->nlink = 1 + 1 + ci->i_subdirs;
         }
+
+        /* Mask off any higher bits (e.g. btime) until we have support */
+        stat->result_mask = request_mask & STATX_BASIC_STATS;
         return err;
 }