Changeset b3c38750 in mainline

Timestamp:

2008-01-06T13:08:32Z (17 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

4db6eaf

Parents:

9413c0d

Message:

Turn the namespace futex into rwlock.

Location:

uspace

Files:

• lib/libc/include/rwlock.h (modified) (1 diff)
• srv/vfs/vfs.h (modified) (1 diff)
• srv/vfs/vfs_mount.c (modified) (4 diffs)
• srv/vfs/vfs_open.c (modified) (4 diffs)
• srv/vfs/vfs_unlink.c (modified) (1 diff)

uspace/lib/libc/include/rwlock.h

@@ -45 +45 @@
 typedef atomic_t rwlock_t;
 
+#define RWLOCK_INITIALIZE(rwlock)       \
+    rwlock_t rwlock = FUTEX_INITIALIZER
+
 #define rwlock_initialize(rwlock)       futex_initialize((rwlock), 1)
 #define rwlock_reader_lock(rwlock)      futex_down((rwlock))

uspace/srv/vfs/vfs.h

@@ -174 +174 @@
 extern link_t plb_head;         /**< List of active PLB entries. */
 
-/** Holding this futex prevents extern changes in file system namespace. */ 
-atomic_t namespace_futex;
+/** Holding this rwlock prevents changes in file system namespace. */ 
+extern rwlock_t namespace_rwlock;
 
 extern int vfs_grab_phone(int);

uspace/srv/vfs/vfs_mount.c

@@ -183 +183 @@
                  * We already have the root FS.
                  */
-                futex_down(&namespace_futex);
+                rwlock_writer_lock(&namespace_rwlock);
                 rc = vfs_lookup_internal(buf, size, &mp, NULL);
                 if (rc != EOK) {
@@ -189 +189 @@
                          * The lookup failed for some reason.
                          */
-                        futex_up(&namespace_futex);
+                        rwlock_writer_unlock(&namespace_rwlock);
                         futex_up(&rootfs_futex);
                         vfs_node_put(mr_node);  /* failed -> drop reference */
@@ -198 +198 @@
                 mp_node = vfs_node_get(&mp);
                 if (!mp_node) {
-                        futex_up(&namespace_futex);
+                        rwlock_writer_unlock(&namespace_rwlock);
                         futex_up(&rootfs_futex);
                         vfs_node_put(mr_node);  /* failed -> drop reference */
@@ -210 +210 @@
                  * This prevents the mount point from being deleted.
                  */
-                futex_up(&namespace_futex);
+                rwlock_writer_unlock(&namespace_rwlock);
         } else {
                 /*

uspace/srv/vfs/vfs_open.c

@@ -39 +39 @@
 #include <async.h>
 #include <errno.h>
-#include <futex.h>
+#include <rwlock.h>
 #include <sys/types.h>
 #include <stdlib.h>
@@ -94 +94 @@
          * triplet.
          */
-        futex_down(&namespace_futex);
+        rwlock_reader_lock(&namespace_rwlock);
 
         /*
@@ -102 +102 @@
         rc = vfs_lookup_internal(path, size, &triplet, NULL);
         if (rc) {
-                futex_up(&namespace_futex);
+                rwlock_reader_unlock(&namespace_rwlock);
                 ipc_answer_0(rid, rc);
                 free(path);
@@ -114 +114 @@
 
         vfs_node_t *node = vfs_node_get(&triplet);
-        futex_up(&namespace_futex);
+        rwlock_reader_unlock(&namespace_rwlock);
 
         /*

uspace/srv/vfs/vfs_unlink.c

@@ -36 +36 @@
  */
 
-#include <atomic.h>
-#include <futex.h>
+#include <rwlock.h>
 
 /**
- * This futex prevents the race between a triplet-to-VFS-node resolution and a
+ * This rwlock prevents the race between a triplet-to-VFS-node resolution and a
  * concurrent VFS operation which modifies the file system namespace.
  */
-atomic_t namespace_futex = FUTEX_INITIALIZER;
+RWLOCK_INITIALIZE(namespace_rwlock);
 
 /**