diff options
| -rw-r--r-- | fs/ubifs/dir.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 8ecabb11a76..936a0388926 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -371,6 +371,24 @@ static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir) */ return 0; + if (file->f_version == 0) { + /* + * The file was seek'ed, which means that @file->private_data + * is now invalid. This may also be just the first + * 'ubifs_readdir()' invocation, in which case + * @file->private_data is NULL, and the below code is + * basically a no-op. + */ + kfree(file->private_data); + file->private_data = NULL; + } + + /* + * 'generic_file_llseek()' unconditionally sets @file->f_version to + * zero, and we use this for detecting whether the file was seek'ed. + */ + file->f_version = 1; + /* File positions 0 and 1 correspond to "." and ".." */ if (pos == 0) { ubifs_assert(!file->private_data); @@ -444,6 +462,14 @@ static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir) file->f_pos = pos = key_hash_flash(c, &dent->key); file->private_data = dent; cond_resched(); + + if (file->f_version == 0) + /* + * The file was seek'ed meanwhile, lets return and start + * reading direntries from the new position on the next + * invocation. + */ + return 0; } out: @@ -454,15 +480,13 @@ out: kfree(file->private_data); file->private_data = NULL; + /* 2 is a special value indicating that there are no more direntries */ file->f_pos = 2; return 0; } -/* If a directory is seeked, we have to free saved readdir() state */ static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin) { - kfree(file->private_data); - file->private_data = NULL; return generic_file_llseek(file, offset, origin); } |