vfs: only add " (deleted)" where necessary

__d_path() has 4 callers:

  d_path()
  sys_getcwd()
  seq_path_root()
  tomoyo_realpath_from_path2()

Of these the only one which needs the " (deleted)" ending is d_path().

sys_getcwd() checks for existence before calling __d_path().

seq_path_root() is used to show the mountpoint path in
/proc/PID/mountinfo, which is always a positive.

And tomoyo doesn't want the deleted ending.

Create a helper "path_with_deleted()" as subsequent patches will need
this in multiple places.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/dcache.c b/fs/dcache.c
index d09d938..7fccb00 100644 (file)
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1979,8 +1979,7 @@ global_root:
  * @buffer: buffer to return value in
  * @buflen: buffer length
  *
- * Convert a dentry into an ASCII path name. If the entry has been deleted
- * the string " (deleted)" is appended. Note that this is ambiguous.
+ * Convert a dentry into an ASCII path name.
  *
  * Returns a pointer into the buffer or an error code if the
  * path was too long.
@@ -1997,12 +1996,6 @@ char *__d_path(const struct path *path, struct path *root,
        int error;
 
        prepend(&res, &buflen, "\0", 1);
-       if (d_unlinked(path->dentry)) {
-               error = prepend(&res, &buflen, " (deleted)", 10);
-               if (error)
-                       return ERR_PTR(error);
-       }
-
        error = prepend_path(path, root, &res, &buflen);
        if (error)
                return ERR_PTR(error);
@@ -2010,6 +2003,22 @@ char *__d_path(const struct path *path, struct path *root,
        return res;
 }
 
+/*
+ * same as __d_path but appends "(deleted)" for unlinked files.
+ */
+static int path_with_deleted(const struct path *path, struct path *root,
+                                char **buf, int *buflen)
+{
+       prepend(buf, buflen, "\0", 1);
+       if (d_unlinked(path->dentry)) {
+               int error = prepend(buf, buflen, " (deleted)", 10);
+               if (error)
+                       return error;
+       }
+
+       return prepend_path(path, root, buf, buflen);
+}
+
 /**
  * d_path - return the path of a dentry
  * @path: path to report
@@ -2028,9 +2037,10 @@ char *__d_path(const struct path *path, struct path *root,
  */
 char *d_path(const struct path *path, char *buf, int buflen)
 {
-       char *res;
+       char *res = buf + buflen;
        struct path root;
        struct path tmp;
+       int error;
 
        /*
         * We have various synthetic filesystems that never get mounted.  On
@@ -2045,7 +2055,9 @@ char *d_path(const struct path *path, char *buf, int buflen)
        get_fs_root(current->fs, &root);
        spin_lock(&dcache_lock);
        tmp = root;
-       res = __d_path(path, &tmp, buf, buflen);
+       error = path_with_deleted(path, &tmp, &res, &buflen);
+       if (error)
+               res = ERR_PTR(error);
        spin_unlock(&dcache_lock);
        path_put(&root);
        return res;