Changes in uspace/srv/vfs/vfs_ops.c [ccca251:e6da6d5] in mainline

File:

• uspace/srv/vfs/vfs_ops.c (modified) (43 diffs)

uspace/srv/vfs/vfs_ops.c

@@ -52 +52 @@
 #include <assert.h>
 #include <vfs/canonify.h>
+#include <vfs/vfs_mtab.h>
+
+FIBRIL_MUTEX_INITIALIZE(mtab_list_lock);
+LIST_INITIALIZE(mtab_list);
+static size_t mtab_size = 0;
 
 /* Forward declarations of static functions. */
-static int vfs_truncate_internal(fs_handle_t, devmap_handle_t, fs_index_t,
+static int vfs_truncate_internal(fs_handle_t, service_id_t, fs_index_t,
     aoff64_t);
 
@@ -65 +70 @@
 vfs_pair_t rootfs = {
         .fs_handle = 0,
-        .devmap_handle = 0
+        .service_id = 0
 };
 
-static void vfs_mount_internal(ipc_callid_t rid, devmap_handle_t devmap_handle,
+static int vfs_mount_internal(ipc_callid_t rid, service_id_t service_id,
     fs_handle_t fs_handle, char *mp, char *opts)
 {
@@ -76 +81 @@
         vfs_node_t *mr_node;
         fs_index_t rindex;
-        size_t rsize;
+        aoff64_t rsize;
         unsigned rlnkcnt;
+        async_exch_t *exch;
         sysarg_t rc;
-        int phone;
         aid_t msg;
         ipc_call_t answer;
@@ -91 +96 @@
                         fibril_rwlock_write_unlock(&namespace_rwlock);
                         async_answer_0(rid, EBUSY);
-                        return;
+                        return EBUSY;
                 }
                 
@@ -99 +104 @@
                         fibril_rwlock_write_unlock(&namespace_rwlock);
                         async_answer_0(rid, rc);
-                        return;
+                        return rc;
                 }
                 
@@ -106 +111 @@
                         fibril_rwlock_write_unlock(&namespace_rwlock);
                         async_answer_0(rid, ENOMEM);
-                        return;
+                        return ENOMEM;
                 }
                 
@@ -123 +128 @@
                         
                         /* Tell the mountee that it is being mounted. */
-                        phone = vfs_grab_phone(fs_handle);
-                        msg = async_send_1(phone, VFS_OUT_MOUNTED,
-                            (sysarg_t) devmap_handle, &answer);
-                        /* send the mount options */
-                        rc = async_data_write_start(phone, (void *)opts,
+                        exch = vfs_exchange_grab(fs_handle);
+                        msg = async_send_1(exch, VFS_OUT_MOUNTED,
+                            (sysarg_t) service_id, &answer);
+                        /* Send the mount options */
+                        rc = async_data_write_start(exch, (void *)opts,
                             str_size(opts));
+                        vfs_exchange_release(exch);
+                        
                         if (rc != EOK) {
                                 async_wait_for(msg, NULL);
-                                vfs_release_phone(fs_handle, phone);
                                 fibril_rwlock_write_unlock(&namespace_rwlock);
                                 async_answer_0(rid, rc);
-                                return;
+                                return rc;
                         }
                         async_wait_for(msg, &rc);
-                        vfs_release_phone(fs_handle, phone);
                         
                         if (rc != EOK) {
                                 fibril_rwlock_write_unlock(&namespace_rwlock);
                                 async_answer_0(rid, rc);
-                                return;
+                                return rc;
                         }
 
                         rindex = (fs_index_t) IPC_GET_ARG1(answer);
-                        rsize = (size_t) IPC_GET_ARG2(answer);
-                        rlnkcnt = (unsigned) IPC_GET_ARG3(answer);
+                        rsize = (aoff64_t) MERGE_LOUP32(IPC_GET_ARG2(answer),
+                            IPC_GET_ARG3(answer));
+                        rlnkcnt = (unsigned) IPC_GET_ARG4(answer);
                         
                         mr_res.triplet.fs_handle = fs_handle;
-                        mr_res.triplet.devmap_handle = devmap_handle;
+                        mr_res.triplet.service_id = service_id;
                         mr_res.triplet.index = rindex;
                         mr_res.size = rsize;
@@ -157 +163 @@
                         
                         rootfs.fs_handle = fs_handle;
-                        rootfs.devmap_handle = devmap_handle;
+                        rootfs.service_id = service_id;
                         
                         /* Add reference to the mounted root. */
@@ -165 +171 @@
                         fibril_rwlock_write_unlock(&namespace_rwlock);
                         async_answer_0(rid, rc);
-                        return;
+                        return rc;
                 } else {
                         /*
@@ -173 +179 @@
                         fibril_rwlock_write_unlock(&namespace_rwlock);
                         async_answer_0(rid, ENOENT);
-                        return;
-                }
-        }
-        
-        /*
-         * At this point, we have all necessary pieces: file system and device
-         * handles, and we know the mount point VFS node.
-         */
-        
-        int mountee_phone = vfs_grab_phone(fs_handle);
-        assert(mountee_phone >= 0);
-
-        phone = vfs_grab_phone(mp_res.triplet.fs_handle);
-        msg = async_send_4(phone, VFS_OUT_MOUNT,
-            (sysarg_t) mp_res.triplet.devmap_handle,
+                        return ENOENT;
+                }
+        }
+        
+        /*
+         * At this point, we have all necessary pieces: file system handle
+         * and service ID, and we know the mount point VFS node.
+         */
+        
+        async_exch_t *mountee_exch = vfs_exchange_grab(fs_handle);
+        assert(mountee_exch);
+        
+        exch = vfs_exchange_grab(mp_res.triplet.fs_handle);
+        msg = async_send_4(exch, VFS_OUT_MOUNT,
+            (sysarg_t) mp_res.triplet.service_id,
             (sysarg_t) mp_res.triplet.index,
             (sysarg_t) fs_handle,
-            (sysarg_t) devmap_handle, &answer);
-        
-        /* send connection */
-        rc = async_req_1_0(phone, IPC_M_CONNECTION_CLONE, mountee_phone);
-        if (rc != EOK) {
+            (sysarg_t) service_id, &answer);
+        
+        /* Send connection */
+        rc = async_exchange_clone(exch, mountee_exch);
+        vfs_exchange_release(mountee_exch);
+        
+        if (rc != EOK) {
+                vfs_exchange_release(exch);
                 async_wait_for(msg, NULL);
-                vfs_release_phone(fs_handle, mountee_phone);
-                vfs_release_phone(mp_res.triplet.fs_handle, phone);
+                
                 /* Mount failed, drop reference to mp_node. */
                 if (mp_node)
                         vfs_node_put(mp_node);
+                
                 async_answer_0(rid, rc);
                 fibril_rwlock_write_unlock(&namespace_rwlock);
-                return;
-        }
-
-        vfs_release_phone(fs_handle, mountee_phone);
+                return rc;
+        }
         
         /* send the mount options */
-        rc = async_data_write_start(phone, (void *)opts, str_size(opts));
-        if (rc != EOK) {
+        rc = async_data_write_start(exch, (void *) opts, str_size(opts));
+        if (rc != EOK) {
+                vfs_exchange_release(exch);
                 async_wait_for(msg, NULL);
-                vfs_release_phone(mp_res.triplet.fs_handle, phone);
+                
                 /* Mount failed, drop reference to mp_node. */
                 if (mp_node)
                         vfs_node_put(mp_node);
+                
                 fibril_rwlock_write_unlock(&namespace_rwlock);
                 async_answer_0(rid, rc);
-                return;
-        }
+                return rc;
+        }
+        
+        /*
+         * Wait for the answer before releasing the exchange to avoid deadlock
+         * in case the answer depends on further calls to the same file system.
+         * Think of a case when mounting a FS on a file_bd backed by a file on
+         * the same FS. 
+         */
         async_wait_for(msg, &rc);
-        vfs_release_phone(mp_res.triplet.fs_handle, phone);
+        vfs_exchange_release(exch);
         
         if (rc == EOK) {
                 rindex = (fs_index_t) IPC_GET_ARG1(answer);
-                rsize = (size_t) IPC_GET_ARG2(answer);
-                rlnkcnt = (unsigned) IPC_GET_ARG3(answer);
-        
+                rsize = (aoff64_t) MERGE_LOUP32(IPC_GET_ARG2(answer),
+                    IPC_GET_ARG3(answer));
+                rlnkcnt = (unsigned) IPC_GET_ARG4(answer);
+                
                 mr_res.triplet.fs_handle = fs_handle;
-                mr_res.triplet.devmap_handle = devmap_handle;
+                mr_res.triplet.service_id = service_id;
                 mr_res.triplet.index = rindex;
                 mr_res.size = rsize;
                 mr_res.lnkcnt = rlnkcnt;
                 mr_res.type = VFS_NODE_DIRECTORY;
-        
+                
                 /* Add reference to the mounted root. */
                 mr_node = vfs_node_get(&mr_res); 
@@ -243 +260 @@
                         vfs_node_put(mp_node);
         }
-
+        
         async_answer_0(rid, rc);
         fibril_rwlock_write_unlock(&namespace_rwlock);
+        return rc;
 }
 
 void vfs_mount(ipc_callid_t rid, ipc_call_t *request)
 {
-        devmap_handle_t devmap_handle;
+        service_id_t service_id;
 
         /*
@@ -257 +275 @@
          * in the request.
          */
-        devmap_handle = (devmap_handle_t) IPC_GET_ARG1(*request);
+        service_id = (service_id_t) IPC_GET_ARG1(*request);
         
         /*
@@ -265 +283 @@
         
         /*
-         * For now, don't make use of ARG3, but it can be used to
-         * carry mount options in the future.
-         */
-        
+         * Instance number is passed as ARG3.
+         */
+        unsigned int instance = IPC_GET_ARG3(*request);
+
         /* We want the client to send us the mount point. */
         char *mp;
@@ -303 +321 @@
         
         /*
-         * Wait for IPC_M_PING so that we can return an error if we don't know
+         * Wait for VFS_IN_PING so that we can return an error if we don't know
          * fs_name.
          */
         ipc_call_t data;
         ipc_callid_t callid = async_get_call(&data);
-        if (IPC_GET_IMETHOD(data) != IPC_M_PING) {
+        if (IPC_GET_IMETHOD(data) != VFS_IN_PING) {
                 async_answer_0(callid, ENOTSUP);
                 async_answer_0(rid, ENOTSUP);
@@ -321 +339 @@
          * This will also give us its file system handle.
          */
-        fibril_mutex_lock(&fs_head_lock);
+        fibril_mutex_lock(&fs_list_lock);
         fs_handle_t fs_handle;
 recheck:
-        fs_handle = fs_name_to_handle(fs_name, false);
+        fs_handle = fs_name_to_handle(instance, fs_name, false);
         if (!fs_handle) {
                 if (flags & IPC_FLAG_BLOCKING) {
-                        fibril_condvar_wait(&fs_head_cv, &fs_head_lock);
+                        fibril_condvar_wait(&fs_list_cv, &fs_list_lock);
                         goto recheck;
                 }
                 
-                fibril_mutex_unlock(&fs_head_lock);
+                fibril_mutex_unlock(&fs_list_lock);
                 async_answer_0(callid, ENOENT);
                 async_answer_0(rid, ENOENT);
@@ -339 +357 @@
                 return;
         }
-        fibril_mutex_unlock(&fs_head_lock);
-        
-        /* Acknowledge that we know fs_name. */
-        async_answer_0(callid, EOK);
-        
+        fibril_mutex_unlock(&fs_list_lock);
+
+        /* Add the filesystem info to the list of mounted filesystems */
+        mtab_ent_t *mtab_ent = malloc(sizeof(mtab_ent_t));
+        if (!mtab_ent) {
+                async_answer_0(callid, ENOMEM);
+                async_answer_0(rid, ENOMEM);
+                free(mp);
+                free(fs_name);
+                free(opts);
+                return;
+        }
+
         /* Do the mount */
-        vfs_mount_internal(rid, devmap_handle, fs_handle, mp, opts);
+        rc = vfs_mount_internal(rid, service_id, fs_handle, mp, opts);
+        if (rc != EOK) {
+                async_answer_0(callid, ENOTSUP);
+                async_answer_0(rid, ENOTSUP);
+                free(mtab_ent);
+                free(mp);
+                free(opts);
+                free(fs_name);
+                return;
+        }
+
+        /* Add the filesystem info to the list of mounted filesystems */
+
+        str_cpy(mtab_ent->mp, MAX_PATH_LEN, mp);
+        str_cpy(mtab_ent->fs_name, FS_NAME_MAXLEN, fs_name);
+        str_cpy(mtab_ent->opts, MAX_MNTOPTS_LEN, opts);
+        mtab_ent->instance = instance;
+        mtab_ent->service_id = service_id;
+
+        link_initialize(&mtab_ent->link);
+
+        fibril_mutex_lock(&mtab_list_lock);
+        list_append(&mtab_ent->link, &mtab_list);
+        mtab_size++;
+        fibril_mutex_unlock(&mtab_list_lock);
+
         free(mp);
         free(fs_name);
         free(opts);
+
+        /* Acknowledge that we know fs_name. */
+        async_answer_0(callid, EOK);
 }
 
@@ -358 +412 @@
         vfs_lookup_res_t mr_res;
         vfs_node_t *mr_node;
-        int phone;
-
+        async_exch_t *exch;
+        
         /*
          * Receive the mount point path.
@@ -367 +421 @@
         if (rc != EOK)
                 async_answer_0(rid, rc);
-
+        
         /*
          * Taking the namespace lock will do two things for us. First, it will
@@ -395 +449 @@
                 return;
         }
-
+        
         /*
          * Count the total number of references for the mounted file system. We
@@ -404 +458 @@
          */
         if (vfs_nodes_refcount_sum_get(mr_node->fs_handle,
-            mr_node->devmap_handle) != 2) {
+            mr_node->service_id) != 2) {
                 fibril_rwlock_write_unlock(&namespace_rwlock);
                 vfs_node_put(mr_node);
@@ -411 +465 @@
                 return;
         }
-
+        
         if (str_cmp(mp, "/") == 0) {
-
+                
                 /*
                  * Unmounting the root file system.
@@ -420 +474 @@
                  * VFS_OUT_UNMOUNTED directly to the mounted file system.
                  */
-
-                free(mp);
-                phone = vfs_grab_phone(mr_node->fs_handle);
-                rc = async_req_1_0(phone, VFS_OUT_UNMOUNTED,
-                    mr_node->devmap_handle);
-                vfs_release_phone(mr_node->fs_handle, phone);
+                
+                exch = vfs_exchange_grab(mr_node->fs_handle);
+                rc = async_req_1_0(exch, VFS_OUT_UNMOUNTED,
+                    mr_node->service_id);
+                vfs_exchange_release(exch);
+                
                 if (rc != EOK) {
                         fibril_rwlock_write_unlock(&namespace_rwlock);
+                        free(mp);
                         vfs_node_put(mr_node);
                         async_answer_0(rid, rc);
                         return;
                 }
+                
                 rootfs.fs_handle = 0;
-                rootfs.devmap_handle = 0;
+                rootfs.service_id = 0;
         } else {
-
+                
                 /*
                  * Unmounting a non-root file system.
@@ -442 +498 @@
                  * file system, so we delegate the operation to it.
                  */
-
+                
                 rc = vfs_lookup_internal(mp, L_MP, &mp_res, NULL);
-                free(mp);
                 if (rc != EOK) {
                         fibril_rwlock_write_unlock(&namespace_rwlock);
+                        free(mp);
                         vfs_node_put(mr_node);
                         async_answer_0(rid, rc);
                         return;
                 }
+                
                 vfs_node_t *mp_node = vfs_node_get(&mp_res);
                 if (!mp_node) {
                         fibril_rwlock_write_unlock(&namespace_rwlock);
+                        free(mp);
                         vfs_node_put(mr_node);
                         async_answer_0(rid, ENOMEM);
                         return;
                 }
-
-                phone = vfs_grab_phone(mp_node->fs_handle);
-                rc = async_req_2_0(phone, VFS_OUT_UNMOUNT,
-                    mp_node->devmap_handle, mp_node->index);
-                vfs_release_phone(mp_node->fs_handle, phone);
+                
+                exch = vfs_exchange_grab(mp_node->fs_handle);
+                rc = async_req_2_0(exch, VFS_OUT_UNMOUNT,
+                    mp_node->service_id, mp_node->index);
+                vfs_exchange_release(exch);
+                
                 if (rc != EOK) {
                         fibril_rwlock_write_unlock(&namespace_rwlock);
+                        free(mp);
                         vfs_node_put(mp_node);
                         vfs_node_put(mr_node);
@@ -470 +530 @@
                         return;
                 }
-
+                
                 /* Drop the reference we got above. */
                 vfs_node_put(mp_node);
@@ -476 +536 @@
                 vfs_node_put(mp_node);
         }
-
-
+        
         /*
          * All went well, the mounted file system was successfully unmounted.
@@ -483 +542 @@
          */
         vfs_node_forget(mr_node);
-
         fibril_rwlock_write_unlock(&namespace_rwlock);
+
+        fibril_mutex_lock(&mtab_list_lock);
+
+        int found = 0;
+
+        list_foreach(mtab_list, cur) {
+                mtab_ent_t *mtab_ent = list_get_instance(cur, mtab_ent_t,
+                    link);
+
+                if (str_cmp(mtab_ent->mp, mp) == 0) {
+                        list_remove(&mtab_ent->link);
+                        mtab_size--;
+                        free(mtab_ent);
+                        found = 1;
+                        break;
+                }
+        }
+        assert(found);
+        fibril_mutex_unlock(&mtab_list_lock);
+
+        free(mp);
+
         async_answer_0(rid, EOK);
 }
@@ -566 +646 @@
                 if (node->size) {
                         rc = vfs_truncate_internal(node->fs_handle,
-                            node->devmap_handle, node->index, 0);
+                            node->service_id, node->index, 0);
                         if (rc) {
                                 fibril_rwlock_write_unlock(&node->contents_rwlock);
@@ -609 +689 @@
 }
 
-void vfs_open_node(ipc_callid_t rid, ipc_call_t *request)
-{
-        // FIXME: check for sanity of the supplied fs, dev and index
-        
-        /*
-         * The interface is open_node(fs, dev, index, oflag).
-         */
-        vfs_lookup_res_t lr;
-        
-        lr.triplet.fs_handle = IPC_GET_ARG1(*request);
-        lr.triplet.devmap_handle = IPC_GET_ARG2(*request);
-        lr.triplet.index = IPC_GET_ARG3(*request);
-        int oflag = IPC_GET_ARG4(*request);
-        
-        fibril_rwlock_read_lock(&namespace_rwlock);
-        
-        int rc = vfs_open_node_internal(&lr);
-        if (rc != EOK) {
-                fibril_rwlock_read_unlock(&namespace_rwlock);
-                async_answer_0(rid, rc);
-                return;
-        }
-        
-        vfs_node_t *node = vfs_node_get(&lr);
-        fibril_rwlock_read_unlock(&namespace_rwlock);
-        
-        /* Truncate the file if requested and if necessary. */
-        if (oflag & O_TRUNC) {
-                fibril_rwlock_write_lock(&node->contents_rwlock);
-                if (node->size) {
-                        rc = vfs_truncate_internal(node->fs_handle,
-                            node->devmap_handle, node->index, 0);
-                        if (rc) {
-                                fibril_rwlock_write_unlock(&node->contents_rwlock);
-                                vfs_node_put(node);
-                                async_answer_0(rid, rc);
-                                return;
-                        }
-                        node->size = 0;
-                }
-                fibril_rwlock_write_unlock(&node->contents_rwlock);
-        }
-        
-        /*
-         * Get ourselves a file descriptor and the corresponding vfs_file_t
-         * structure.
-         */
-        int fd = vfs_fd_alloc((oflag & O_DESC) != 0);
-        if (fd < 0) {
-                vfs_node_put(node);
-                async_answer_0(rid, fd);
-                return;
-        }
-        vfs_file_t *file = vfs_file_get(fd);
-        file->node = node;
-        if (oflag & O_APPEND)
-                file->append = true;
-        
-        /*
-         * The following increase in reference count is for the fact that the
-         * file is being opened and that a file structure is pointing to it.
-         * It is necessary so that the file will not disappear when
-         * vfs_node_put() is called. The reference will be dropped by the
-         * respective VFS_IN_CLOSE.
-         */
-        vfs_node_addref(node);
-        vfs_node_put(node);
-        vfs_file_put(file);
-        
-        /* Success! Return the new file descriptor to the client. */
-        async_answer_1(rid, EOK, fd);
-}
-
 void vfs_sync(ipc_callid_t rid, ipc_call_t *request)
 {
@@ -698 +705 @@
          */
         fibril_mutex_lock(&file->lock);
-        int fs_phone = vfs_grab_phone(file->node->fs_handle);
+        async_exch_t *fs_exch = vfs_exchange_grab(file->node->fs_handle);
         
         /* Make a VFS_OUT_SYMC request at the destination FS server. */
         aid_t msg;
         ipc_call_t answer;
-        msg = async_send_2(fs_phone, VFS_OUT_SYNC, file->node->devmap_handle,
+        msg = async_send_2(fs_exch, VFS_OUT_SYNC, file->node->service_id,
             file->node->index, &answer);
-
+        
+        vfs_exchange_release(fs_exch);
+        
         /* Wait for reply from the FS server. */
         sysarg_t rc;
         async_wait_for(msg, &rc);
         
-        vfs_release_phone(file->node->fs_handle, fs_phone);
         fibril_mutex_unlock(&file->lock);
-
+        
         vfs_file_put(file);
         async_answer_0(rid, rc);
 }
 
-int vfs_close_internal(vfs_file_t *file)
-{
-        /*
-         * Lock the open file structure so that no other thread can manipulate
-         * the same open file at a time.
-         */
-        fibril_mutex_lock(&file->lock);
-        
-        if (file->refcnt <= 1) {
-                /* Only close the file on the destination FS server
-                   if there are no more file descriptors (except the
-                   present one) pointing to this file. */
-                
-                int fs_phone = vfs_grab_phone(file->node->fs_handle);
-                
-                /* Make a VFS_OUT_CLOSE request at the destination FS server. */
-                aid_t msg;
-                ipc_call_t answer;
-                msg = async_send_2(fs_phone, VFS_OUT_CLOSE,
-                    file->node->devmap_handle, file->node->index, &answer);
-                
-                /* Wait for reply from the FS server. */
-                sysarg_t rc;
-                async_wait_for(msg, &rc);
-                
-                vfs_release_phone(file->node->fs_handle, fs_phone);
-                fibril_mutex_unlock(&file->lock);
-                
-                return IPC_GET_ARG1(answer);
-        }
-        
-        fibril_mutex_unlock(&file->lock);
-        return EOK;
-}
-
 void vfs_close(ipc_callid_t rid, ipc_call_t *request)
 {
         int fd = IPC_GET_ARG1(*request);
-        
-        /* Lookup the file structure corresponding to the file descriptor. */
-        vfs_file_t *file = vfs_file_get(fd);
-        if (!file) {
-                async_answer_0(rid, ENOENT);
-                return;
-        }
-        
-        int ret = vfs_close_internal(file);
-        if (ret != EOK)
-                async_answer_0(rid, ret);
-        
-        vfs_file_put(file);
-        ret = vfs_fd_free(fd);
+        int ret = vfs_fd_free(fd);
         async_answer_0(rid, ret);
 }
@@ -774 +734 @@
 static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
 {
-        vfs_info_t *vi;
-
         /*
          * The following code strongly depends on the fact that the files data
@@ -785 +743 @@
          * open files supports parallel access!
          */
-
+        
         int fd = IPC_GET_ARG1(*request);
         
@@ -800 +758 @@
          */
         fibril_mutex_lock(&file->lock);
-
-        vi = fs_handle_to_info(file->node->fs_handle);
-        assert(vi);
-
+        
+        vfs_info_t *fs_info = fs_handle_to_info(file->node->fs_handle);
+        assert(fs_info);
+        
         /*
          * Lock the file's node so that no other client can read/write to it at
@@ -809 +767 @@
          * write implementation does not modify the file size.
          */
-        if (read || (vi->concurrent_read_write && vi->write_retains_size))
+        if ((read) ||
+            ((fs_info->concurrent_read_write) && (fs_info->write_retains_size)))
                 fibril_rwlock_read_lock(&file->node->contents_rwlock);
         else
                 fibril_rwlock_write_lock(&file->node->contents_rwlock);
-
+        
         if (file->node->type == VFS_NODE_DIRECTORY) {
                 /*
@@ -823 +782 @@
         }
         
-        int fs_phone = vfs_grab_phone(file->node->fs_handle);
+        async_exch_t *fs_exch = vfs_exchange_grab(file->node->fs_handle);
         
         /*
@@ -835 +794 @@
         ipc_call_t answer;
         if (read) {
-                rc = async_data_read_forward_3_1(fs_phone, VFS_OUT_READ,
-                    file->node->devmap_handle, file->node->index, file->pos,
-                    &answer);
+                rc = async_data_read_forward_4_1(fs_exch, VFS_OUT_READ,
+                    file->node->service_id, file->node->index,
+                    LOWER32(file->pos), UPPER32(file->pos), &answer);
         } else {
                 if (file->append)
                         file->pos = file->node->size;
                 
-                rc = async_data_write_forward_3_1(fs_phone, VFS_OUT_WRITE,
-                    file->node->devmap_handle, file->node->index, file->pos,
-                    &answer);
-        }
-        
-        vfs_release_phone(file->node->fs_handle, fs_phone);
+                rc = async_data_write_forward_4_1(fs_exch, VFS_OUT_WRITE,
+                    file->node->service_id, file->node->index,
+                    LOWER32(file->pos), UPPER32(file->pos), &answer);
+        }
+        
+        vfs_exchange_release(fs_exch);
         
         size_t bytes = IPC_GET_ARG1(answer);
@@ -855 +814 @@
         
         /* Unlock the VFS node. */
-        if (read || (vi->concurrent_read_write && vi->write_retains_size))
+        if ((read) ||
+            ((fs_info->concurrent_read_write) && (fs_info->write_retains_size)))
                 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
         else {
                 /* Update the cached version of node's size. */
                 if (rc == EOK)
-                        file->node->size = IPC_GET_ARG2(answer); 
+                        file->node->size = MERGE_LOUP32(IPC_GET_ARG2(answer),
+                            IPC_GET_ARG3(answer));
                 fibril_rwlock_write_unlock(&file->node->contents_rwlock);
         }
@@ -972 +933 @@
 }
 
-int vfs_truncate_internal(fs_handle_t fs_handle, devmap_handle_t devmap_handle,
+int vfs_truncate_internal(fs_handle_t fs_handle, service_id_t service_id,
     fs_index_t index, aoff64_t size)
 {
-        sysarg_t rc;
-        int fs_phone;
-        
-        fs_phone = vfs_grab_phone(fs_handle);
-        rc = async_req_4_0(fs_phone, VFS_OUT_TRUNCATE, (sysarg_t) devmap_handle,
-            (sysarg_t) index, LOWER32(size), UPPER32(size));
-        vfs_release_phone(fs_handle, fs_phone);
-        return (int)rc;
+        async_exch_t *exch = vfs_exchange_grab(fs_handle);
+        sysarg_t rc = async_req_4_0(exch, VFS_OUT_TRUNCATE,
+            (sysarg_t) service_id, (sysarg_t) index, LOWER32(size),
+            UPPER32(size));
+        vfs_exchange_release(exch);
+        
+        return (int) rc;
 }
 
@@ -1001 +961 @@
         fibril_rwlock_write_lock(&file->node->contents_rwlock);
         rc = vfs_truncate_internal(file->node->fs_handle,
-            file->node->devmap_handle, file->node->index, size);
+            file->node->service_id, file->node->index, size);
         if (rc == EOK)
                 file->node->size = size;
@@ -1032 +992 @@
         fibril_mutex_lock(&file->lock);
 
-        int fs_phone = vfs_grab_phone(file->node->fs_handle);
+        async_exch_t *exch = vfs_exchange_grab(file->node->fs_handle);
         
         aid_t msg;
-        msg = async_send_3(fs_phone, VFS_OUT_STAT, file->node->devmap_handle,
+        msg = async_send_3(exch, VFS_OUT_STAT, file->node->service_id,
             file->node->index, true, NULL);
-        async_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
+        async_forward_fast(callid, exch, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
+        
+        vfs_exchange_release(exch);
+        
         async_wait_for(msg, &rc);
-        vfs_release_phone(file->node->fs_handle, fs_phone);
-
+        
         fibril_mutex_unlock(&file->lock);
         vfs_file_put(file);
@@ -1083 +1045 @@
         fibril_rwlock_read_unlock(&namespace_rwlock);
 
-        int fs_phone = vfs_grab_phone(node->fs_handle);
+        async_exch_t *exch = vfs_exchange_grab(node->fs_handle);
+        
         aid_t msg;
-        msg = async_send_3(fs_phone, VFS_OUT_STAT, node->devmap_handle,
+        msg = async_send_3(exch, VFS_OUT_STAT, node->service_id,
             node->index, false, NULL);
-        async_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
+        async_forward_fast(callid, exch, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
+        
+        vfs_exchange_release(exch);
         
         sysarg_t rv;
         async_wait_for(msg, &rv);
-        vfs_release_phone(node->fs_handle, fs_phone);
 
         async_answer_0(rid, rv);
@@ -1261 +1225 @@
         /* Check whether linking to the same file system instance. */
         if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) ||
-            (old_node->devmap_handle != new_par_lr.triplet.devmap_handle)) {
+            (old_node->service_id != new_par_lr.triplet.service_id)) {
                 fibril_rwlock_write_unlock(&namespace_rwlock);
                 vfs_node_put(old_node);
@@ -1369 +1333 @@
         fibril_mutex_lock(&oldfile->lock);
         
-        /* Lookup an open file structure possibly corresponding to newfd. */
-        vfs_file_t *newfile = vfs_file_get(newfd);
-        if (newfile) {
-                /* Close the originally opened file. */
-                int ret = vfs_close_internal(newfile);
-                if (ret != EOK) {
-                        fibril_mutex_unlock(&oldfile->lock);
-                        vfs_file_put(oldfile);
-                        vfs_file_put(newfile);
-                        async_answer_0(rid, ret);
-                        return;
-                }
-                
-                ret = vfs_fd_free(newfd);
-                if (ret != EOK) {
-                        fibril_mutex_unlock(&oldfile->lock);
-                        vfs_file_put(oldfile);
-                        vfs_file_put(newfile);
-                        async_answer_0(rid, ret);
-                        return;
-                }
-                vfs_file_put(newfile);
-        }
+        /* Make sure newfd is closed. */
+        (void) vfs_fd_free(newfd);
         
         /* Assign the old file to newfd. */
@@ -1404 +1347 @@
 }
 
+void vfs_wait_handle(ipc_callid_t rid, ipc_call_t *request)
+{
+        int fd = vfs_wait_handle_internal();
+        async_answer_1(rid, EOK, fd);
+}
+
+void vfs_get_mtab(ipc_callid_t rid, ipc_call_t *request)
+{
+        ipc_callid_t callid;
+        ipc_call_t data;
+        sysarg_t rc = EOK;
+        size_t len;
+
+        fibril_mutex_lock(&mtab_list_lock);
+
+        /* Send to the caller the number of mounted filesystems */
+        callid = async_get_call(&data);
+        if (IPC_GET_IMETHOD(data) != VFS_IN_PING) {
+                rc = ENOTSUP;
+                async_answer_0(callid, rc);
+                goto exit;
+        }
+        async_answer_1(callid, EOK, mtab_size);
+
+        list_foreach(mtab_list, cur) {
+                mtab_ent_t *mtab_ent = list_get_instance(cur, mtab_ent_t,
+                    link);
+
+                rc = ENOTSUP;
+
+                if (!async_data_read_receive(&callid, &len)) {
+                        async_answer_0(callid, rc);
+                        goto exit;
+                }
+
+                (void) async_data_read_finalize(callid, mtab_ent->mp,
+                    str_size(mtab_ent->mp));
+
+                if (!async_data_read_receive(&callid, &len)) {
+                        async_answer_0(callid, rc);
+                        goto exit;
+                }
+
+                (void) async_data_read_finalize(callid, mtab_ent->opts,
+                    str_size(mtab_ent->opts));
+
+                if (!async_data_read_receive(&callid, &len)) {
+                        async_answer_0(callid, rc);
+                        goto exit;
+                }
+
+                (void) async_data_read_finalize(callid, mtab_ent->fs_name,
+                    str_size(mtab_ent->fs_name));
+
+                callid = async_get_call(&data);
+
+                if (IPC_GET_IMETHOD(data) != VFS_IN_PING) {
+                        async_answer_0(callid, rc);
+                        goto exit;
+                }
+
+                rc = EOK;
+                async_answer_2(callid, rc, mtab_ent->instance,
+                    mtab_ent->service_id);
+        }
+
+exit:
+        fibril_mutex_unlock(&mtab_list_lock);
+        async_answer_0(rid, rc);
+}
+
 /**
  * @}