Changeset 2b20947 in mainline for uspace/srv/vfs/vfs.c

Timestamp:

2007-09-15T14:47:57Z (17 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

a0edf5f

Parents:

d0b72c4

Message:

VFS work.
Delve deeper into VFS_REGISTER.

File:

• uspace/srv/vfs/vfs.c (modified) (7 diffs)

uspace/srv/vfs/vfs.c

@@ -41 +41 @@
 #include <errno.h>
 #include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
 #include <bool.h>
+#include <futex.h>
+#include <libadt/list.h>
 #include "vfs.h"
 
+atomic_t fs_head_futex = FUTEX_INITIALIZER;
+link_t fs_head;
+
 /** Verify the VFS info structure.
  *
@@ -50 +57 @@
  * @return              Non-zero if the info structure is sane, zero otherwise.
  */
-static int vfs_info_sane(vfs_info_t *info)
-{
-        return 1;       /* XXX */
+static bool vfs_info_sane(vfs_info_t *info)
+{
+        int i;
+
+        /*
+         * Check if the name is non-empty and is composed solely of ASCII
+         * characters [a-z]+[a-z0-9_-]*.
+         */
+        if (!islower(info->name[0]))
+                return false;
+        for (i = 1; i < FS_NAME_MAXLEN; i++) {
+                if (!(islower(info->name[i]) || isdigit(info->name[i])) &&
+                    (info->name[i] != '-') && (info->name[i] != '_')) {
+                        if (info->name[i] == '\0')
+                                break;
+                        else
+                                return false;
+                }
+        }
+        
+
+        /*
+         * Check if the FS implements mandatory VFS operations.
+         */
+        if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_REGISTER)] != VFS_OP_DEFINED)
+                return false;
+        if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] != VFS_OP_DEFINED)
+                return false;
+        if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] != VFS_OP_DEFINED)
+                return false;
+        if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_OPEN)] != VFS_OP_DEFINED)
+                return false;
+        if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_CLOSE)] != VFS_OP_DEFINED)
+                return false;
+        if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_READ)] != VFS_OP_DEFINED)
+                return false;
+        
+        /*
+         * Check if each operation is either not defined, defined or default.
+         */
+        for (i = VFS_FIRST; i < VFS_LAST; i++) {
+                if ((IPC_METHOD_TO_VFS_OP(i) != VFS_OP_NULL) && 
+                    (IPC_METHOD_TO_VFS_OP(i) != VFS_OP_DEFAULT) && 
+                    (IPC_METHOD_TO_VFS_OP(i) != VFS_OP_DEFINED))
+                        return false;   
+        }
+        return true;
 }
 
@@ -81 +132 @@
         
         /*
-         * We know the size of the info structure. See if the client understands
-         * this easy concept too.
+         * We know the size of the VFS info structure. See if the client
+         * understands this easy concept too.
          */
         if (size != sizeof(vfs_info_t)) {
@@ -93 +144 @@
                 return;
         }
-        vfs_info_t *info;
-
-        /*
-         * Allocate a buffer for the info structure.
-         */
-        info = (vfs_info_t *) malloc(sizeof(vfs_info_t));
-        if (!info) {
+        fs_info_t *fs_info;
+
+        /*
+         * Allocate and initialize a buffer for the fs_info structure.
+         */
+        fs_info = (fs_info_t *) malloc(sizeof(fs_info_t));
+        if (!fs_info) {
                 ipc_answer_fast(callid, ENOMEM, 0, 0);
                 ipc_answer_fast(rid, ENOMEM, 0, 0);
                 return;
         }
-                
-        rc = ipc_data_send_answer(callid, &call, info, size);
+        link_initialize(&fs_info->fs_link);
+                
+        rc = ipc_data_send_answer(callid, &call, &fs_info->vfs_info, size);
         if (!rc) {
-                free(info);
+                free(fs_info);
                 ipc_answer_fast(callid, rc, 0, 0);
                 ipc_answer_fast(rid, rc, 0, 0);
@@ -113 +165 @@
         }
                 
-        if (!vfs_info_sane(info)) {
-                free(info);
+        if (!vfs_info_sane(&fs_info->vfs_info)) {
+                free(fs_info);
                 ipc_answer_fast(callid, EINVAL, 0, 0);
                 ipc_answer_fast(rid, EINVAL, 0, 0);
@@ -120 +172 @@
         }
                 
+        futex_down(&fs_head_futex);
+
+        /*
+         * Check for duplicit registrations.
+         */
+        link_t *cur;
+        for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
+                fs_info_t *fi = list_get_instance(cur, fs_info_t,
+                    fs_link);
+                /* TODO: replace strcmp with strncmp once we have it */
+                if (strcmp(fs_info->vfs_info.name, fi->vfs_info.name) == 0) {
+                        /*
+                         * We already register a fs like this.
+                         */
+                        futex_up(&fs_head_futex);
+                        free(fs_info);
+                        ipc_answer_fast(callid, EEXISTS, 0, 0);
+                        ipc_answer_fast(rid, EEXISTS, 0, 0);
+                        return;
+                }
+        }
+        
+        /*
+         * TODO:
+         * 1. send the client the IPC_M_CONNECT_TO_ME call so that it makes a
+         *    callback connection.
+         * 2. add the fs_info into fs_head
+         */
+
+        futex_up(&fs_head_futex);
 }
 
@@ -178 +260 @@
         ipcarg_t phonead;
 
+        list_initialize(&fs_head);
         async_set_client_connection(vfs_connection);
         ipc_connect_to_me(PHONE_NS, SERVICE_VFS, 0, &phonead);