Changeset 8ffedd8 in mainline for uspace/lib/c/generic/vfs/vfs.c

Timestamp:

2017-03-16T16:50:29Z (7 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

5a2b765

Parents:

35b7d86e

Message:

Partially revive support for mount table listing and walking

This implementation is purely client-based. Using a simple file system
traversal, the library figures out what are the actual mountpoints. It
only discovers mountpoints that it can reach from its VFS root.

The benefit is that this works and produces reasonable results even in
the environment of per-client VFS roots, whereas a global mount table
would present paths that might not make any sense to the client
(notwithstanding the fact that VFS no longer knows the mountpoint
paths).

Listing of file system names is still broken as of this commit.

File:

• uspace/lib/c/generic/vfs/vfs.c (modified) (2 diffs)

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

@@ -35 +35 @@
 #include <vfs/canonify.h>
 #include <vfs/vfs.h>
+#include <vfs/vfs_mtab.h>
 #include <vfs/vfs_sess.h>
 #include <macros.h>
@@ -1104 +1105 @@
 }
 
+static void process_mp(const char *path, struct stat *stat, list_t *mtab_list)
+{
+        mtab_ent_t *ent;
+
+        ent = (mtab_ent_t *) malloc(sizeof(mtab_ent_t));
+        if (!ent)
+                return;
+
+        link_initialize(&ent->link);
+        str_cpy(ent->mp, sizeof(ent->mp), path);
+        str_cpy(ent->fs_name, sizeof(ent->fs_name), "fixme");
+        ent->service_id = stat->service_id;
+        
+        list_append(&ent->link, mtab_list);
+}
+
+static int vfs_get_mtab_visit(const char *path, list_t *mtab_list,
+    fs_handle_t fs_handle, service_id_t service_id)
+{
+        DIR *dir;
+        struct dirent *dirent;
+
+        dir = opendir(path);
+        if (!dir)
+                return -1;
+
+        while ((dirent = readdir(dir)) != NULL) {
+                char *child;
+                struct stat st;
+                int rc;
+
+                rc = asprintf(&child, "%s/%s", path, dirent->d_name);
+                if (rc < 0) {
+                        closedir(dir);
+                        errno = rc;
+                        return -1;
+                }
+
+                rc = stat(child, &st);
+                if (rc != 0) {
+                        free(child);
+                        closedir(dir);
+                        errno = rc;
+                        return -1;
+                }
+
+                if (st.fs_handle != fs_handle || st.service_id != service_id) {
+                        /*
+                         * We have discovered a mountpoint.
+                         */
+                        process_mp(child, &st, mtab_list);
+                }
+
+                if (st.is_directory) {
+                        (void) vfs_get_mtab_visit(child, mtab_list,
+                            st.fs_handle, st.service_id);
+                }
+
+                free(child);
+        }
+
+        closedir(dir);
+        return EOK;
+}
+
 int vfs_get_mtab_list(list_t *mtab_list)
 {
-        sysarg_t rc = ENOTSUP;
-        
-        return rc;
+        struct stat st;
+
+        int rc = stat("/", &st);
+        if (rc != 0)
+                return rc;
+
+        process_mp("/", &st, mtab_list);
+
+        return vfs_get_mtab_visit("", mtab_list, st.fs_handle, st.service_id);
 }