Changes in uspace/srv/vfs/vfs_ops.c [27b76ca:e6da6d5] in mainline

File:

• uspace/srv/vfs/vfs_ops.c (modified) (37 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)
 {
@@ -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;
                 }
                 
@@ -125 +130 @@
                         exch = vfs_exchange_grab(fs_handle);
                         msg = async_send_1(exch, VFS_OUT_MOUNTED,
-                            (sysarg_t) devmap_handle, &answer);
+                            (sysarg_t) service_id, &answer);
                         /* Send the mount options */
                         rc = async_data_write_start(exch, (void *)opts,
@@ -135 +140 @@
                                 fibril_rwlock_write_unlock(&namespace_rwlock);
                                 async_answer_0(rid, rc);
-                                return;
+                                return rc;
                         }
                         async_wait_for(msg, &rc);
@@ -142 +147 @@
                                 fibril_rwlock_write_unlock(&namespace_rwlock);
                                 async_answer_0(rid, rc);
-                                return;
+                                return rc;
                         }
 
                         rindex = (fs_index_t) IPC_GET_ARG1(answer);
-                        rsize = (aoff64_t) MERGE_LOUP32(IPC_GET_ARG2(answer), 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.
+                        return ENOENT;
+                }
+        }
+        
+        /*
+         * At this point, we have all necessary pieces: file system handle
+         * and service ID, and we know the mount point VFS node.
          */
         
@@ -187 +193 @@
         exch = vfs_exchange_grab(mp_res.triplet.fs_handle);
         msg = async_send_4(exch, VFS_OUT_MOUNT,
-            (sysarg_t) mp_res.triplet.devmap_handle,
+            (sysarg_t) mp_res.triplet.service_id,
             (sysarg_t) mp_res.triplet.index,
             (sysarg_t) fs_handle,
-            (sysarg_t) devmap_handle, &answer);
+            (sysarg_t) service_id, &answer);
         
         /* Send connection */
@@ -206 +212 @@
                 async_answer_0(rid, rc);
                 fibril_rwlock_write_unlock(&namespace_rwlock);
-                return;
+                return rc;
         }
         
@@ -221 +227 @@
                 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_exchange_release(exch);
-        async_wait_for(msg, &rc);
         
         if (rc == EOK) {
@@ -234 +246 @@
                 
                 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;
@@ -251 +263 @@
         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;
 
         /*
@@ -262 +275 @@
          * in the request.
          */
-        devmap_handle = (devmap_handle_t) IPC_GET_ARG1(*request);
+        service_id = (service_id_t) IPC_GET_ARG1(*request);
         
         /*
@@ -270 +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;
@@ -329 +342 @@
         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) {
@@ -345 +358 @@
         }
         fibril_mutex_unlock(&fs_list_lock);
-        
-        /* Acknowledge that we know fs_name. */
-        async_answer_0(callid, EOK);
-        
+
+        /* 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);
 }
 
@@ -409 +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);
@@ -426 +475 @@
                  */
                 
-                free(mp);
-                
                 exch = vfs_exchange_grab(mr_node->fs_handle);
                 rc = async_req_1_0(exch, VFS_OUT_UNMOUNTED,
-                    mr_node->devmap_handle);
+                    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);
@@ -441 +489 @@
                 
                 rootfs.fs_handle = 0;
-                rootfs.devmap_handle = 0;
+                rootfs.service_id = 0;
         } else {
                 
@@ -452 +500 @@
                 
                 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);
@@ -463 +511 @@
                 if (!mp_node) {
                         fibril_rwlock_write_unlock(&namespace_rwlock);
+                        free(mp);
                         vfs_node_put(mr_node);
                         async_answer_0(rid, ENOMEM);
@@ -470 +519 @@
                 exch = vfs_exchange_grab(mp_node->fs_handle);
                 rc = async_req_2_0(exch, VFS_OUT_UNMOUNT,
-                    mp_node->devmap_handle, mp_node->index);
+                    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);
@@ -492 +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);
 }
@@ -575 +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);
@@ -639 +710 @@
         aid_t msg;
         ipc_call_t answer;
-        msg = async_send_2(fs_exch, VFS_OUT_SYNC, file->node->devmap_handle,
+        msg = async_send_2(fs_exch, VFS_OUT_SYNC, file->node->service_id,
             file->node->index, &answer);
         
@@ -724 +795 @@
         if (read) {
                 rc = async_data_read_forward_4_1(fs_exch, VFS_OUT_READ,
-                    file->node->devmap_handle, file->node->index,
+                    file->node->service_id, file->node->index,
                     LOWER32(file->pos), UPPER32(file->pos), &answer);
         } else {
@@ -731 +802 @@
                 
                 rc = async_data_write_forward_4_1(fs_exch, VFS_OUT_WRITE,
-                    file->node->devmap_handle, file->node->index,
+                    file->node->service_id, file->node->index,
                     LOWER32(file->pos), UPPER32(file->pos), &answer);
         }
@@ -862 +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)
 {
         async_exch_t *exch = vfs_exchange_grab(fs_handle);
         sysarg_t rc = async_req_4_0(exch, VFS_OUT_TRUNCATE,
-            (sysarg_t) devmap_handle, (sysarg_t) index, LOWER32(size),
+            (sysarg_t) service_id, (sysarg_t) index, LOWER32(size),
             UPPER32(size));
         vfs_exchange_release(exch);
@@ -890 +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;
@@ -924 +995 @@
         
         aid_t msg;
-        msg = async_send_3(exch, 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, exch, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
@@ -977 +1048 @@
         
         aid_t msg;
-        msg = async_send_3(exch, 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, exch, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
@@ -1154 +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);
@@ -1282 +1353 @@
 }
 
+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);
+}
+
 /**
  * @}