b=13276

r=shadow,wangdi

check return value of ll_node_from_inode in ll_file_read and ll_file_sendfile,
do not try to access uninitialised locks tree on error exit from
ll_file_write

lustre/ChangeLog

@@ -78,6 +78,12 @@ Details    : Flock locks might destroy just granted lock if it could be merged
 	     so teach ldlm_cli_enquque_fini that this is a valid case for
 	     flock locks.
 
+Severity   : minor
+Bugzilla   : 13276
+Frequency  : rare
+Description: Oops in read and write path when failing to allocate lock.
+Details    : Check if lock allocation failed and return error back.
+
 --------------------------------------------------------------------------------
 
 2007-08-10         Cluster File Systems, Inc. <info@clusterfs.com>

lustre/llite/file.c

@@ -1362,6 +1362,10 @@ repeat:
         }
 
         node = ll_node_from_inode(inode, *ppos, end, LCK_PR);
+        if (IS_ERR(node)){
+                GOTO(out, rc = PTR_ERR(node));
+        }
+
         tree.lt_fd = LUSTRE_FPRIVATE(file);
         rc = ll_tree_lock(&tree, node, buf, count,
                           file->f_flags & O_NONBLOCK ? LDLM_FL_BLOCK_NOWAIT :0);
@@ -1536,7 +1540,7 @@ repeat:
 
         if (*ppos >= maxbytes) {
                 send_sig(SIGXFSZ, current, 0);
-                GOTO(out, retval = -EFBIG);
+                GOTO(out_unlock, retval = -EFBIG);
         }
         if (*ppos + count > maxbytes)
                 count = maxbytes - *ppos;
@@ -1548,9 +1552,10 @@ repeat:
         retval = generic_file_write(file, buf, chunk, ppos);
         ll_rw_stats_tally(ll_i2sbi(inode), current->pid, file, count, 1);
 
-out:
+out_unlock:
         ll_tree_unlock(&tree);
 
+out:
         if (retval > 0) {
                 buf += retval;
                 count -= retval;
@@ -1602,6 +1607,9 @@ static ssize_t ll_file_sendfile(struct file *in_file, loff_t *ppos,size_t count,
                 RETURN(generic_file_sendfile(in_file, ppos, count, actor, target));
 
         node = ll_node_from_inode(inode, *ppos, *ppos + count - 1, LCK_PR);
+        if (IS_ERR(node))
+                RETURN(PTR_ERR(node));
+
         tree.lt_fd = LUSTRE_FPRIVATE(in_file);
         rc = ll_tree_lock(&tree, node, NULL, count,
                           in_file->f_flags & O_NONBLOCK?LDLM_FL_BLOCK_NOWAIT:0);