Changeset ee1b8ca in mainline for uspace/srv/fs/tmpfs/tmpfs_ops.c

Timestamp:

2007-12-25T20:02:25Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

c1bf5cb

Parents:

1356a04c

Message:

VFS and TMPFS support for VFS_WRITE.

File:

• uspace/srv/fs/tmpfs/tmpfs_ops.c (modified) (1 diff)

uspace/srv/fs/tmpfs/tmpfs_ops.c

@@ -316 +316 @@
 }
 
+void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)
+{
+        int dev_handle = IPC_GET_ARG1(*request);
+        unsigned long index = IPC_GET_ARG2(*request);
+        off_t pos = IPC_GET_ARG3(*request);
+
+        /*
+         * Lookup the respective dentry.
+         */
+        link_t *hlp;
+        hlp = hash_table_find(&dentries, &index);
+        if (!hlp) {
+                ipc_answer_0(rid, ENOENT);
+                return;
+        }
+        tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
+            dh_link);
+
+        /*
+         * Receive the write request.
+         */
+        ipc_callid_t callid;
+        size_t size;
+        if (!ipc_data_write_receive(&callid, NULL, &size)) {
+                ipc_answer_0(callid, EINVAL);   
+                ipc_answer_0(rid, EINVAL);
+                return;
+        }
+
+        /*
+         * 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);
+        if (!newdata) {
+                ipc_answer_0(callid, ENOMEM);
+                ipc_answer_1(rid, EOK, 0);
+                return;
+        }
+        dentry->size = size;
+        dentry->data = newdata;
+        (void) ipc_data_write_deliver(callid, dentry->data + pos, size);
+
+        /*
+         * Answer the VFS_WRITE call.
+         */
+        ipc_answer_1(rid, EOK, size);
+}
+
 /**
  * @}