Changes in uspace/srv/vfs/vfs_ops.c [3a4b3ba:c2f4b6b] in mainline

File:

• uspace/srv/vfs/vfs_ops.c (modified) (3 diffs)

uspace/srv/vfs/vfs_ops.c

@@ -781 +781 @@
 static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
 {
+        vfs_info_t *vi;
 
         /*
@@ -807 +808 @@
         fibril_mutex_lock(&file->lock);
 
+        vi = fs_handle_to_info(file->node->fs_handle);
+        assert(vi);
+
         /*
          * Lock the file's node so that no other client can read/write to it at
-         * the same time.
-         */
-        if (read)
+         * the same time unless the FS supports concurrent reads/writes and its
+         * write implementation does not modify the file size.
+         */
+        if (read || (vi->concurrent_read_write && vi->write_retains_size))
                 fibril_rwlock_read_lock(&file->node->contents_rwlock);
         else
@@ -857 +862 @@
         
         /* Unlock the VFS node. */
-        if (read)
+        if (read || (vi->concurrent_read_write && vi->write_retains_size))
                 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
         else {