From 17e78d307926fa0ab4ba3d62393b8e53022895d1 Mon Sep 17 00:00:00 2001 From: Erez Zadok Date: Wed, 25 Jun 2014 23:42:59 -0400 Subject: [PATCH] Wrapfs: fix ->llseek to update upper and lower offsets Fixes bug: xfstests generic/257. f_pos consistently is required by and only by dir_ops->wrapfs_readdir, main_ops is not affected. Signed-off-by: Erez Zadok Signed-off-by: Mengyang Li --- fs/wrapfs/file.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/fs/wrapfs/file.c b/fs/wrapfs/file.c index 21112bd79e61..993242ea99e9 100644 --- a/fs/wrapfs/file.c +++ b/fs/wrapfs/file.c @@ -289,6 +289,28 @@ out: return err; } +/* + * Wrapfs cannot use generic_file_llseek as ->llseek, because it would + * only set the offset of the upper file. So we have to implement our + * own method to set both the upper and lower file offsets + * consistently. + */ +static loff_t wrapfs_file_llseek(struct file *file, loff_t offset, int whence) +{ + int err; + struct file *lower_file; + + err = generic_file_llseek(file, offset, whence); + if (err < 0) + goto out; + + lower_file = wrapfs_lower_file(file); + err = generic_file_llseek(lower_file, offset, whence); + +out: + return err; +} + const struct file_operations wrapfs_main_fops = { .llseek = generic_file_llseek, .read = wrapfs_read, @@ -306,7 +328,7 @@ const struct file_operations wrapfs_main_fops = { /* trimmed directory options */ const struct file_operations wrapfs_dir_fops = { - .llseek = generic_file_llseek, + .llseek = wrapfs_file_llseek, .read = generic_read_dir, .readdir = wrapfs_readdir, .unlocked_ioctl = wrapfs_ioctl, -- 2.43.0