Changeset b7b6753 in mainline for uspace/srv/fs/fat/fat_idx.c

Timestamp:

2008-06-06T20:44:18Z (16 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

1c03c17

Parents:

cde485d

Message:

Put a frequently used construct into a function.

File:

• uspace/srv/fs/fat/fat_idx.c (modified) (5 diffs)

uspace/srv/fs/fat/fat_idx.c

@@ -84 +84 @@
 }
 
+static unused_t *unused_find(dev_handle_t dev_handle, bool lock)
+{
+        unused_t *u;
+        link_t *l;
+
+        if (lock)
+                futex_down(&unused_futex);
+        for (l = unused_head.next; l != &unused_head; l = l->next) {
+                u = list_get_instance(l, unused_t, link);
+                if (u->dev_handle == dev_handle) 
+                        return u;
+        }
+        if (lock)
+                futex_up(&unused_futex);
+        return NULL;
+}
+
 /** Futex protecting the up_hash and ui_hash. */
 static futex_t used_futex = FUTEX_INITIALIZER; 
@@ -200 +217 @@
 static bool fat_idx_alloc(dev_handle_t dev_handle, fs_index_t *index)
 {
-        link_t *l;
         unused_t *u;
         
         assert(index);
-        futex_down(&unused_futex);
-        for (l = unused_head.next; l != &unused_head; l = l->next) {
-                u = list_get_instance(l, unused_t, link);
-                if (u->dev_handle == dev_handle) 
-                        goto hit;
-        }
-        futex_up(&unused_futex);
-        
-        /* dev_handle not found */
-        return false;   
-
-hit:
+        u = unused_find(dev_handle, true);
+        if (!u)
+                return false;   
+
         if (list_empty(&u->freed_head)) {
                 if (u->remaining) { 
@@ -271 +279 @@
 static void fat_idx_free(dev_handle_t dev_handle, fs_index_t index)
 {
-        link_t *l;
         unused_t *u;
 
-        futex_down(&unused_futex);
-        for (l = unused_head.next; l != &unused_head; l = l->next) {
-                u = list_get_instance(l, unused_t, link);
-                if (u->dev_handle == dev_handle)
-                        goto hit;
-        }
-        futex_up(&unused_futex);
-
-        /* should not happen */
-        assert(0);
-
-hit:
+        u = unused_find(dev_handle, true);
+        assert(u);
+
         if (u->next == index + 1) {
                 /* The index can be returned directly to the counter. */
@@ -431 +429 @@
 int fat_idx_init_by_dev_handle(dev_handle_t dev_handle)
 {
-        unused_t *u = (unused_t *) malloc(sizeof(unused_t));
+        unused_t *u;
+        int rc = EOK;
+
+        u = (unused_t *) malloc(sizeof(unused_t));
         if (!u)
                 return ENOMEM;
         unused_initialize(u, dev_handle);
         futex_down(&unused_futex);
-        list_append(&u->link, &unused_head);
+        if (!unused_find(dev_handle, false))
+                list_append(&u->link, &unused_head);
+        else
+                rc = EEXIST;
         futex_up(&unused_futex);
-        return EOK;
+        return rc;
 }
 
@@ -444 +448 @@
 {
         unused_t *u;
-        link_t *l;
-
-        futex_down(&unused_futex);
-        for (l = unused_head.next; l != &unused_head; l = l->next) {
-                u = list_get_instance(l, unused_t, link);
-                if (u->dev_handle == dev_handle) 
-                        goto hit;
-        }
-        futex_up(&unused_futex);
-
-        assert(false);  /* should not happen */
-
-hit:
+
+        u = unused_find(dev_handle, true);
+        assert(u);
         list_remove(&u->link);
         futex_up(&unused_futex);