Changes in uspace/srv/vfs/vfs_register.c [b72efe8:ffa2c8ef] in mainline

File:

• uspace/srv/vfs/vfs_register.c (modified) (18 diffs)

uspace/srv/vfs/vfs_register.c

@@ -52 +52 @@
 #include "vfs.h"
 
-FIBRIL_CONDVAR_INITIALIZE(fs_list_cv);
-FIBRIL_MUTEX_INITIALIZE(fs_list_lock);
-LIST_INITIALIZE(fs_list);
+FIBRIL_CONDVAR_INITIALIZE(fs_head_cv);
+FIBRIL_MUTEX_INITIALIZE(fs_head_lock);
+LIST_INITIALIZE(fs_head);
 
 atomic_t fs_handle_next = {
@@ -62 +62 @@
 /** Verify the VFS info structure.
  *
- * @param info Info structure to be verified.
- *
- * @return Non-zero if the info structure is sane, zero otherwise.
- *
+ * @param info          Info structure to be verified.
+ *
+ * @return              Non-zero if the info structure is sane, zero otherwise.
  */
 static bool vfs_info_sane(vfs_info_t *info)
 {
         int i;
-        
+
         /*
          * Check if the name is non-empty and is composed solely of ASCII
@@ -79 +78 @@
                 return false;
         }
-        
         for (i = 1; i < FS_NAME_MAXLEN; i++) {
                 if (!(islower(info->name[i]) || isdigit(info->name[i])) &&
@@ -92 +90 @@
                 }
         }
-        
         /*
          * This check is not redundant. It ensures that the name is
@@ -107 +104 @@
 /** VFS_REGISTER protocol function.
  *
- * @param rid     Hash of the call with the request.
- * @param request Call structure with the request.
- *
+ * @param rid           Hash of the call with the request.
+ * @param request       Call structure with the request.
  */
 void vfs_register(ipc_callid_t rid, ipc_call_t *request)
 {
+        int phone;
+        
         dprintf("Processing VFS_REGISTER request received from %p.\n",
             request->in_phone_hash);
@@ -149 +147 @@
         }
         
-        fibril_mutex_lock(&fs_list_lock);
+        fibril_mutex_lock(&fs_head_lock);
         
         /*
@@ -159 +157 @@
                  */
                 dprintf("FS is already registered.\n");
-                fibril_mutex_unlock(&fs_list_lock);
+                fibril_mutex_unlock(&fs_head_lock);
                 free(fs_info);
                 async_answer_0(rid, EEXISTS);
@@ -169 +167 @@
          */
         dprintf("Inserting FS into the list of registered file systems.\n");
-        list_append(&fs_info->fs_link, &fs_list);
+        list_append(&fs_info->fs_link, &fs_head);
         
         /*
@@ -176 +174 @@
          * which to forward VFS requests to it.
          */
-        fs_info->sess = async_callback_receive(EXCHANGE_PARALLEL);
-        if (!fs_info->sess) {
-                dprintf("Callback connection expected\n");
+        ipc_call_t call;
+        ipc_callid_t callid = async_get_call(&call);
+        if (IPC_GET_IMETHOD(call) != IPC_M_CONNECT_TO_ME) {
+                dprintf("Unexpected call, method = %d\n", IPC_GET_IMETHOD(call));
                 list_remove(&fs_info->fs_link);
-                fibril_mutex_unlock(&fs_list_lock);
-                free(fs_info);
+                fibril_mutex_unlock(&fs_head_lock);
+                free(fs_info);
+                async_answer_0(callid, EINVAL);
                 async_answer_0(rid, EINVAL);
                 return;
         }
         
+        phone = IPC_GET_ARG5(call);
+        async_session_create(&fs_info->session, phone, 0);
+        async_answer_0(callid, EOK);
+        
         dprintf("Callback connection to FS created.\n");
         
@@ -193 +197 @@
         
         size_t size;
-        ipc_callid_t callid;
         if (!async_share_in_receive(&callid, &size)) {
                 dprintf("Unexpected call, method = %d\n", IPC_GET_IMETHOD(call));
                 list_remove(&fs_info->fs_link);
-                fibril_mutex_unlock(&fs_list_lock);
-                async_hangup(fs_info->sess);
+                fibril_mutex_unlock(&fs_head_lock);
+                async_session_destroy(&fs_info->session);
+                async_hangup(phone);
                 free(fs_info);
                 async_answer_0(callid, EINVAL);
@@ -211 +215 @@
                 dprintf("Client suggests wrong size of PFB, size = %d\n", size);
                 list_remove(&fs_info->fs_link);
-                fibril_mutex_unlock(&fs_list_lock);
-                async_hangup(fs_info->sess);
+                fibril_mutex_unlock(&fs_head_lock);
+                async_session_destroy(&fs_info->session);
+                async_hangup(phone);
                 free(fs_info);
                 async_answer_0(callid, EINVAL);
@@ -235 +240 @@
         async_answer_1(rid, EOK, (sysarg_t) fs_info->fs_handle);
         
-        fibril_condvar_broadcast(&fs_list_cv);
-        fibril_mutex_unlock(&fs_list_lock);
+        fibril_condvar_broadcast(&fs_head_cv);
+        fibril_mutex_unlock(&fs_head_lock);
         
         dprintf("\"%.*s\" filesystem successfully registered, handle=%d.\n",
@@ -242 +247 @@
 }
 
-/** Begin an exchange for a given file system handle
- *
- * @param handle File system handle.
- *
- * @return Exchange for a multi-call request.
- * @return NULL if no such file exists.
- *
- */
-async_exch_t *vfs_exchange_grab(fs_handle_t handle)
-{
-        /*
-         * For now, we don't try to be very clever and very fast.
-         * We simply lookup the session in fs_list and
-         * begin an exchange.
-         */
-        fibril_mutex_lock(&fs_list_lock);
-        
-        list_foreach(fs_list, cur) {
-                fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
-                
+/** For a given file system handle, implement policy for allocating a phone.
+ *
+ * @param handle        File system handle.
+ *
+ * @return              Phone over which a multi-call request can be safely
+ *                      sent. Return 0 if no phone was found.
+ */
+int vfs_grab_phone(fs_handle_t handle)
+{
+        link_t *cur;
+        fs_info_t *fs;
+        int phone;
+
+        /*
+         * For now, we don't try to be very clever and very fast.  We simply
+         * lookup the phone in the fs_head list and duplicate it.  The duplicate
+         * phone will be returned to the client and the client will use it for
+         * communication.  In the future, we should cache the connections so
+         * that they do not have to be reestablished over and over again.
+         */
+        fibril_mutex_lock(&fs_head_lock);
+        for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
+                fs = list_get_instance(cur, fs_info_t, fs_link);
                 if (fs->fs_handle == handle) {
-                        fibril_mutex_unlock(&fs_list_lock);
-                        
-                        assert(fs->sess);
-                        async_exch_t *exch = async_exchange_begin(fs->sess);
-                        
-                        assert(exch);
-                        return exch;
-                }
-        }
-        
-        fibril_mutex_unlock(&fs_list_lock);
-        
-        return NULL;
-}
-
-/** End VFS server exchange.
- *
- * @param exch   VFS server exchange.
- *
- */
-void vfs_exchange_release(async_exch_t *exch)
-{
-        async_exchange_end(exch);
+                        fibril_mutex_unlock(&fs_head_lock);
+                        phone = async_exchange_begin(&fs->session);
+
+                        assert(phone > 0);
+                        return phone;
+                }
+        }
+        fibril_mutex_unlock(&fs_head_lock);
+        return 0;
+}
+
+/** Tell VFS that the phone is not needed anymore.
+ *
+ * @param phone         Phone to FS task.
+ */
+void vfs_release_phone(fs_handle_t handle, int phone)
+{
+        link_t *cur;
+        fs_info_t *fs;
+
+        fibril_mutex_lock(&fs_head_lock);
+        for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
+                fs = list_get_instance(cur, fs_info_t, fs_link);
+                if (fs->fs_handle == handle) {
+                        fibril_mutex_unlock(&fs_head_lock);
+                        async_exchange_end(&fs->session, phone);
+                        return;
+                }
+        }
+        /* should not really get here */
+        abort();
+        fibril_mutex_unlock(&fs_head_lock);
 }
 
 /** Convert file system name to its handle.
  *
- * @param name File system name.
- * @param lock If true, the function will lock and unlock the
- *             fs_list_lock.
- *
- * @return File system handle or zero if file system not found.
- *
+ * @param name          File system name.
+ * @param lock          If true, the function will lock and unlock the
+ *                      fs_head_lock.
+ *
+ * @return              File system handle or zero if file system not found.
  */
 fs_handle_t fs_name_to_handle(char *name, bool lock)
@@ -302 +318 @@
         
         if (lock)
-                fibril_mutex_lock(&fs_list_lock);
-        
-        list_foreach(fs_list, cur) {
+                fibril_mutex_lock(&fs_head_lock);
+        link_t *cur;
+        for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
                 fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
                 if (str_cmp(fs->vfs_info.name, name) == 0) { 
@@ -311 +327 @@
                 }
         }
-        
         if (lock)
-                fibril_mutex_unlock(&fs_list_lock);
-        
+                fibril_mutex_unlock(&fs_head_lock);
         return handle;
 }
@@ -320 +334 @@
 /** Find the VFS info structure.
  *
- * @param handle FS handle for which the VFS info structure is sought.
- *
- * @return VFS info structure on success or NULL otherwise.
- *
+ * @param handle        FS handle for which the VFS info structure is sought.
+ * @return              VFS info structure on success or NULL otherwise.
  */
 vfs_info_t *fs_handle_to_info(fs_handle_t handle)
 {
         vfs_info_t *info = NULL;
-        
-        fibril_mutex_lock(&fs_list_lock);
-        list_foreach(fs_list, cur) {
+        link_t *cur;
+
+        fibril_mutex_lock(&fs_head_lock);
+        for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
                 fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
                 if (fs->fs_handle == handle) { 
@@ -337 +350 @@
                 }
         }
-        fibril_mutex_unlock(&fs_list_lock);
-        
+        fibril_mutex_unlock(&fs_head_lock);
+
         return info;
 }
@@ -344 +357 @@
 /**
  * @}
- */
+ */