Changeset 778d26d in mainline

Timestamp:

2013-07-28T21:06:34Z (11 years ago)

Author:

Jiri Zarevucky <zarevucky.jiri@…>

Branches:

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

Children:

9e9b168

Parents:

bf9dc4e2

Message:

Relativize rename().

Location:

uspace

Files:

• lib/c/generic/vfs/vfs.c (modified) (1 diff)
• lib/c/include/ipc/vfs.h (modified) (1 diff)
• lib/fs/libfs.c (modified) (2 diffs)
• srv/vfs/vfs_ops.c (modified) (2 diffs)

uspace/lib/c/generic/vfs/vfs.c

@@ -730 +730 @@
         async_exch_t *exch = vfs_exchange_begin();
         
-        req = async_send_0(exch, VFS_IN_RENAME, NULL);
+        req = async_send_1(exch, VFS_IN_RENAME, -1, NULL);
         rc = async_data_write_start(exch, olda, olda_size);
         if (rc != EOK) {

uspace/lib/c/include/ipc/vfs.h

@@ -126 +126 @@
 
 /**
+ * Lookup will not cross any mount points.
+ * If the lookup would have to cross a mount point, it returns EXDEV instead.
+ */
+#define L_DISABLE_MOUNTS        4
+
+/**
  * Lookup will succeed only if the object is a mount point. The flag is mutually
  * exclusive with L_FILE and L_ROOT.

uspace/lib/fs/libfs.c

@@ -632 +632 @@
         
         if (cur->mp_data.mp_active) {
+                if (lflag & L_DISABLE_MOUNTS) {
+                        async_answer_0(rid, EXDEV);
+                        LOG_EXIT(EXDEV);
+                        goto out;
+                }
+                
                 async_exch_t *exch = async_exchange_begin(cur->mp_data.sess);
                 async_forward_slow(rid, exch, VFS_OUT_LOOKUP, next, last - next,
@@ -692 +698 @@
                 if ((tmp) && (tmp->mp_data.mp_active) &&
                     (!(lflag & L_MP) || (next < last))) {
+                        
+                        if (lflag & L_DISABLE_MOUNTS) {
+                                async_answer_0(rid, EXDEV);
+                                LOG_EXIT(EXDEV);
+                                goto out;
+                        }
+                        
                         async_exch_t *exch = async_exchange_begin(tmp->mp_data.sess);
                         async_forward_slow(rid, exch, VFS_OUT_LOOKUP, next,

uspace/srv/vfs/vfs_ops.c

@@ -1138 +1138 @@
 }
 
+static size_t shared_path(char *a, char *b)
+{
+        size_t res = 0;
+        
+        while (a[res] == b[res] && a[res] != 0) {
+                res++;
+        }
+        
+        if (a[res] == b[res]) {
+                return res;
+        }
+        
+        res--;
+        while (a[res] != '/') {
+                res--;
+        }
+        return res;
+}
+
+static int vfs_rename_internal(vfs_triplet_t *base, char *old, char *new)
+{
+        assert(base != NULL);
+        assert(old != NULL);
+        assert(new != NULL);
+        
+        vfs_lookup_res_t base_lr;
+        vfs_lookup_res_t old_lr;
+        vfs_lookup_res_t new_lr_orig;
+        bool orig_unlinked = false;
+        
+        int rc;
+        
+        size_t shared = shared_path(old, new);
+        
+        /* Do not allow one path to be a prefix of the other. */
+        if (old[shared] == 0 || new[shared] == 0) {
+                return EINVAL;
+        }
+        assert(old[shared] == '/');
+        assert(new[shared] == '/');
+        
+        fibril_rwlock_write_lock(&namespace_rwlock);
+        
+        /* Resolve the shared portion of the path first. */
+        if (shared != 0) {
+                old[shared] = 0;
+                rc = vfs_lookup_internal(base, old, L_DIRECTORY, &base_lr);
+                if (rc != EOK) {
+                        fibril_rwlock_write_unlock(&namespace_rwlock);
+                        return rc;
+                }
+                
+                base = &base_lr.triplet;
+                old[shared] = '/';
+                old += shared;
+                new += shared;
+        }
+        
+        
+        rc = vfs_lookup_internal(base, new, L_UNLINK | L_DISABLE_MOUNTS, &new_lr_orig);
+        if (rc == EOK) {
+                orig_unlinked = true;
+        } else if (rc != ENOENT) {
+                fibril_rwlock_write_unlock(&namespace_rwlock);
+                return rc;
+        }
+        
+        rc = vfs_lookup_internal(base, old, L_UNLINK | L_DISABLE_MOUNTS, &old_lr);
+        if (rc != EOK) {
+                if (orig_unlinked) {
+                        vfs_link_internal(base, new, &new_lr_orig.triplet);
+                }
+                fibril_rwlock_write_unlock(&namespace_rwlock);
+                return rc;
+        }
+        
+        rc = vfs_link_internal(base, new, &old_lr.triplet);
+        if (rc != EOK) {
+                vfs_link_internal(base, old, &old_lr.triplet);
+                if (orig_unlinked) {
+                        vfs_link_internal(base, new, &new_lr_orig.triplet);
+                }
+                fibril_rwlock_write_unlock(&namespace_rwlock);
+                return rc;
+        }
+        
+        if (orig_unlinked) {
+                vfs_node_t *node = vfs_node_get(&new_lr_orig);
+                vfs_node_delref(node);
+                vfs_node_put(node);
+        }
+        
+        fibril_rwlock_write_unlock(&namespace_rwlock);
+        return EOK;
+}
+
 void vfs_rename(ipc_callid_t rid, ipc_call_t *request)
 {
+        /* The common base directory. */
+        int basefd;
+        char *old = NULL;
+        char *new = NULL;
+        vfs_file_t *base = NULL;
+        int rc;
+        
+        basefd = IPC_GET_ARG1(*request);
+        
         /* Retrieve the old path. */
-        char *old;
-        int rc = async_data_write_accept((void **) &old, true, 0, 0, 0, NULL);
-        if (rc != EOK) {
-                async_answer_0(rid, rc);
-                return;
+        rc = async_data_write_accept((void **) &old, true, 0, 0, 0, NULL);
+        if (rc != EOK) {
+                goto out;
         }
         
         /* Retrieve the new path. */
-        char *new;
         rc = async_data_write_accept((void **) &new, true, 0, 0, 0, NULL);
         if (rc != EOK) {
-                free(old);
-                async_answer_0(rid, rc);
-                return;
+                goto out;
         }
         
@@ -1163 +1263 @@
         
         if ((!oldc) || (!newc)) {
-                async_answer_0(rid, EINVAL);
+                rc = EINVAL;
+                goto out;
+        }
+        
+        assert(oldc[olen] == '\0');
+        assert(newc[nlen] == '\0');
+        
+        /* Lookup the file structure corresponding to the file descriptor. */
+        vfs_node_t *base_node = root;
+        // TODO: Client-side root.
+        if (basefd != -1) {
+                base = vfs_file_get(basefd);
+                if (!base) {
+                        rc = EBADF;
+                        goto out;
+                }
+                base_node = base->node;
+        }
+        
+        rc = vfs_rename_internal((vfs_triplet_t *) base_node, oldc, newc);
+
+out:
+        async_answer_0(rid, rc);
+
+        if (old) {
                 free(old);
+        }
+        if (new) {
                 free(new);
-                return;
-        }
-        
-        oldc[olen] = '\0';
-        newc[nlen] = '\0';
-        
-        if ((!str_lcmp(newc, oldc, str_length(oldc))) &&
-            ((newc[str_length(oldc)] == '/') ||
-            (str_length(oldc) == 1) ||
-            (str_length(oldc) == str_length(newc)))) {
-                /*
-                 * oldc is a prefix of newc and either
-                 * - newc continues with a / where oldc ends, or
-                 * - oldc was / itself, or
-                 * - oldc and newc are equal.
-                 */
-                async_answer_0(rid, EINVAL);
-                free(old);
-                free(new);
-                return;
-        }
-        
-        vfs_lookup_res_t old_lr;
-        vfs_lookup_res_t new_lr;
-        vfs_lookup_res_t new_par_lr;
-        fibril_rwlock_write_lock(&namespace_rwlock);
-        
-        /* Lookup the node belonging to the old file name. */
-        rc = vfs_lookup_internal((vfs_triplet_t *) root, oldc, L_NONE, &old_lr);
-        if (rc != EOK) {
-                fibril_rwlock_write_unlock(&namespace_rwlock);
-                async_answer_0(rid, rc);
-                free(old);
-                free(new);
-                return;
-        }
-        
-        vfs_node_t *old_node = vfs_node_get(&old_lr);
-        if (!old_node) {
-                fibril_rwlock_write_unlock(&namespace_rwlock);
-                async_answer_0(rid, ENOMEM);
-                free(old);
-                free(new);
-                return;
-        }
-        
-        /* Determine the path to the parent of the node with the new name. */
-        char *parentc = str_dup(newc);
-        if (!parentc) {
-                fibril_rwlock_write_unlock(&namespace_rwlock);
-                vfs_node_put(old_node);
-                async_answer_0(rid, rc);
-                free(old);
-                free(new);
-                return;
-        }
-        
-        char *lastsl = str_rchr(parentc + 1, '/');
-        if (lastsl)
-                *lastsl = '\0';
-        else
-                parentc[1] = '\0';
-        
-        /* Lookup parent of the new file name. */
-        rc = vfs_lookup_internal((vfs_triplet_t *) root, parentc, L_NONE, &new_par_lr);
-        free(parentc);  /* not needed anymore */
-        if (rc != EOK) {
-                fibril_rwlock_write_unlock(&namespace_rwlock);
-                vfs_node_put(old_node);
-                async_answer_0(rid, rc);
-                free(old);
-                free(new);
-                return;
-        }
-        
-        /* Check whether linking to the same file system instance. */
-        if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) ||
-            (old_node->service_id != new_par_lr.triplet.service_id)) {
-                fibril_rwlock_write_unlock(&namespace_rwlock);
-                vfs_node_put(old_node);
-                async_answer_0(rid, EXDEV);     /* different file systems */
-                free(old);
-                free(new);
-                return;
-        }
-        
-        /* Destroy the old link for the new name. */
-        vfs_node_t *new_node = NULL;
-        rc = vfs_lookup_internal((vfs_triplet_t *) root, newc, L_UNLINK, &new_lr);
-        
-        switch (rc) {
-        case ENOENT:
-                /* simply not in our way */
-                break;
-        case EOK:
-                new_node = vfs_node_get(&new_lr);
-                if (!new_node) {
-                        fibril_rwlock_write_unlock(&namespace_rwlock);
-                        vfs_node_put(old_node);
-                        async_answer_0(rid, ENOMEM);
-                        free(old);
-                        free(new);
-                        return;
-                }
-                fibril_mutex_lock(&nodes_mutex);
-                new_node->lnkcnt--;
-                fibril_mutex_unlock(&nodes_mutex);
-                break;
-        default:
-                fibril_rwlock_write_unlock(&namespace_rwlock);
-                vfs_node_put(old_node);
-                async_answer_0(rid, ENOTEMPTY);
-                free(old);
-                free(new);
-                return;
-        }
-        
-        /* Create the new link for the new name. */
-        rc = vfs_link_internal((vfs_triplet_t *) root, newc, (vfs_triplet_t *) old_node);
-        if (rc != EOK) {
-                fibril_rwlock_write_unlock(&namespace_rwlock);
-                vfs_node_put(old_node);
-                if (new_node)
-                        vfs_node_put(new_node);
-                async_answer_0(rid, rc);
-                free(old);
-                free(new);
-                return;
-        }
-        
-        fibril_mutex_lock(&nodes_mutex);
-        old_node->lnkcnt++;
-        fibril_mutex_unlock(&nodes_mutex);
-        
-        /* Destroy the link for the old name. */
-        rc = vfs_lookup_internal((vfs_triplet_t *) root, oldc, L_UNLINK, NULL);
-        if (rc != EOK) {
-                fibril_rwlock_write_unlock(&namespace_rwlock);
-                vfs_node_put(old_node);
-                if (new_node)
-                        vfs_node_put(new_node);
-                async_answer_0(rid, rc);
-                free(old);
-                free(new);
-                return;
-        }
-        
-        fibril_mutex_lock(&nodes_mutex);
-        old_node->lnkcnt--;
-        fibril_mutex_unlock(&nodes_mutex);
-        fibril_rwlock_write_unlock(&namespace_rwlock);
-        vfs_node_put(old_node);
-        
-        if (new_node)
-                vfs_node_put(new_node);
-        
-        free(old);
-        free(new);
-        async_answer_0(rid, EOK);
+        }
+        if (base) {
+                vfs_file_put(base);
+        }
 }