Changeset c1bf5cb in mainline

Timestamp:

2007-12-26T00:50:49Z (17 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

8d46bf2

Parents:

ee1b8ca

Message:

The previous commit was not entirely sane.
Handle VFS_WRITE correctly when the file doesn't grow.
Handle it correctly also when the file grows.

File:

• uspace/srv/fs/tmpfs/tmpfs_ops.c (modified) (2 diffs)

uspace/srv/fs/tmpfs/tmpfs_ops.c

@@ -346 +346 @@
 
         /*
+         * Check whether the file needs to grow.
+         */
+        if (pos + size <= dentry->size) {
+                /* The file size is not changing. */
+                (void) ipc_data_write_deliver(callid, dentry->data + pos, size);
+                ipc_answer_1(rid, EOK, size);
+                return;
+        }
+        size_t delta = (pos + size) - dentry->size;
+        /*
          * At this point, we are deliberately extremely straightforward and
-         * simply realloc the contents of the file on every write. In the end,
-         * the situation might not be as bad as it may look: our heap allocator
-         * can save us and just grow the block whenever possible.
-         */
-        void *newdata = realloc(dentry->data, size);
+         * simply realloc the contents of the file on every write that grows the
+         * file. In the end, the situation might not be as bad as it may look:
+         * our heap allocator can save us and just grow the block whenever
+         * possible.
+         */
+        void *newdata = realloc(dentry->data, dentry->size + delta);
         if (!newdata) {
                 ipc_answer_0(callid, ENOMEM);
@@ -357 +368 @@
                 return;
         }
-        dentry->size = size;
+        dentry->size += delta;
         dentry->data = newdata;
         (void) ipc_data_write_deliver(callid, dentry->data + pos, size);
-
-        /*
-         * Answer the VFS_WRITE call.
-         */
         ipc_answer_1(rid, EOK, size);
 }