Changeset 5bcd5b7 in mainline for uspace/srv/vfs/vfs_lookup.c

Timestamp:

2013-07-29T14:36:57Z (11 years ago)

Author:

Jiri Zarevucky <zarevucky.jiri@…>

Branches:

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

Children:

4636a60

Parents:

677745a

Message:

Add support for server-side mounts.

File:

• uspace/srv/vfs/vfs_lookup.c (modified) (6 diffs)

uspace/srv/vfs/vfs_lookup.c

@@ -153 +153 @@
 }
 
-int vfs_link_internal(vfs_triplet_t *base, char *path, vfs_triplet_t *child)
+int vfs_link_internal(vfs_node_t *base, char *path, vfs_triplet_t *child)
 {
         assert(base != NULL);
@@ -173 +173 @@
         path = npath;
         
+        vfs_triplet_t *triplet;
+        
         char *slash = _strrchr(path, '/');
         if (slash && slash != path) {
@@ -187 +189 @@
                         goto out;
                 }
-                base = &res.triplet;
+                triplet = &res.triplet;
                 
                 *slash = '/';
         } else {
+                if (base->mount != NULL) {
+                        rc = EINVAL;
+                        goto out;
+                }
+                
                 memcpy(component, path + 1, str_size(path));
-        }
-        
-        if (base->fs_handle != child->fs_handle || base->service_id != child->service_id) {
+                triplet = (vfs_triplet_t *) base;
+        }
+        
+        if (triplet->fs_handle != child->fs_handle || triplet->service_id != child->service_id) {
                 rc = EXDEV;
                 goto out;
         }
         
-        async_exch_t *exch = vfs_exchange_grab(base->fs_handle);
-        aid_t req = async_send_3(exch, VFS_OUT_LINK, base->service_id, base->index, child->index, NULL);
+        async_exch_t *exch = vfs_exchange_grab(triplet->fs_handle);
+        aid_t req = async_send_3(exch, VFS_OUT_LINK, triplet->service_id, triplet->index, child->index, NULL);
         
         rc = async_data_write_start(exch, component, str_size(component) + 1);
@@ -215 +223 @@
 }
 
+static int out_lookup(vfs_triplet_t *base, unsigned *pfirst, unsigned *plen,
+        int lflag, vfs_lookup_res_t *result)
+{
+        assert(base);
+        assert(result);
+        
+        sysarg_t rc;
+        ipc_call_t answer;
+        async_exch_t *exch = vfs_exchange_grab(base->fs_handle);
+        aid_t req = async_send_5(exch, VFS_OUT_LOOKUP, (sysarg_t) *pfirst, (sysarg_t) *plen,
+            (sysarg_t) base->service_id, (sysarg_t) base->index, (sysarg_t) lflag, &answer);
+        async_wait_for(req, &rc);
+        vfs_exchange_release(exch);
+        
+        if ((int) rc < 0) {
+                return (int) rc;
+        }
+        
+        unsigned last = *pfirst + *plen;
+        *pfirst = IPC_GET_ARG3(answer);
+        *plen = last - *pfirst;
+        
+        result->triplet.fs_handle = (fs_handle_t) rc;
+        result->triplet.service_id = (service_id_t) IPC_GET_ARG1(answer);
+        result->triplet.index = (fs_index_t) IPC_GET_ARG2(answer);
+        result->size = (int64_t)(int32_t) IPC_GET_ARG4(answer);
+        result->type = IPC_GET_ARG5(answer);
+        return EOK;
+}
+
 /** Perform a path lookup.
  *
@@ -227 +265 @@
  *
  */
-int vfs_lookup_internal(vfs_triplet_t *base, char *path, int lflag, vfs_lookup_res_t *result)
+int vfs_lookup_internal(vfs_node_t *base, char *path, int lflag, vfs_lookup_res_t *result)
 {
         assert(base != NULL);
         assert(path != NULL);
         
-        sysarg_t rc;
-        
-        if (!base->fs_handle) {
-                rc = ENOENT;
-                goto out;
-        }
-        
         size_t len;
+        int rc;
         char *npath = canonify(path, &len);
         if (!npath) {
+                DPRINTF("vfs_lookup_internal() can't canonify path: %s\n", path);
                 rc = EINVAL;
-                goto out;
+                return rc;
         }
         path = npath;
@@ -254 +287 @@
         rc = plb_insert_entry(&entry, path, &first, len);
         if (rc != EOK) {
-                goto out;
-        }
-        
-        ipc_call_t answer;
-        async_exch_t *exch = vfs_exchange_grab(base->fs_handle);
-        aid_t req = async_send_5(exch, VFS_OUT_LOOKUP, (sysarg_t) first, (sysarg_t) len,
-            (sysarg_t) base->service_id, (sysarg_t) base->index, (sysarg_t) lflag, &answer);
-        async_wait_for(req, &rc);
-        vfs_exchange_release(exch);
-        
+                DPRINTF("vfs_lookup_internal() can't insert entry into PLB: %d\n", rc);
+                return rc;
+        }
+        
+        size_t next = first;
+        size_t nlen = len;
+        
+        vfs_lookup_res_t res;
+        
+        /* Resolve path as long as there are mount points to cross. */
+        while (nlen > 0) {
+                while (base->mount != NULL) {
+                        if (lflag & L_DISABLE_MOUNTS) {
+                                rc = EXDEV;
+                                goto out;
+                        }
+                        
+                        base = base->mount;
+                }
+                
+                rc = out_lookup((vfs_triplet_t *) base, &next, &nlen, lflag, &res);
+                if (rc != EOK) {
+                        goto out;
+                }
+                
+                if (nlen > 0) {
+                        base = vfs_node_peek(&res);
+                        if (base == NULL || base->mount == NULL) {
+                                rc = ENOENT;
+                                goto out;
+                        }
+                        if (lflag & L_DISABLE_MOUNTS) {
+                                rc = EXDEV;
+                                goto out;
+                        }
+                }
+        }
+        
+        assert(nlen == 0);
+        rc = EOK;
+        
+        if (result != NULL) {
+                /* The found file may be a mount point. Try to cross it. */
+                if (!(lflag & L_MP)) {
+                        base = vfs_node_peek(&res);
+                        if (base != NULL && base->mount != NULL) {
+                                while (base->mount != NULL) {
+                                        base = base->mount;
+                                }
+                                
+                                result->triplet = *(vfs_triplet_t *)base;
+                                result->type = base->type;
+                                result->size = base->size;                              
+                                goto out;
+                        }
+                }
+
+                __builtin_memcpy(result, &res, sizeof(vfs_lookup_res_t));
+        }
+        
+out:
         plb_clear_entry(&entry, first, len);
-        
-        if ((int) rc < 0) {
-                goto out;
-        }
-        
-        unsigned last = IPC_GET_ARG3(answer);
-        if (last != first + len) {
-                /* The path wasn't processed entirely. */
-                rc = ENOENT;
-                goto out;
-        }
-        
-        if (!result) {
-                rc = EOK;
-                goto out;
-        }
-        
-        result->triplet.fs_handle = (fs_handle_t) rc;
-        result->triplet.service_id = (service_id_t) IPC_GET_ARG1(answer);
-        result->triplet.index = (fs_index_t) IPC_GET_ARG2(answer);
-        result->size = (int64_t)(int32_t) IPC_GET_ARG4(answer);
-        result->type = IPC_GET_ARG5(answer);
-        rc = EOK;
-
-out:
         DPRINTF("vfs_lookup_internal() with path '%s' returns %d\n", path, rc);
         return rc;