| From 01d8885785a60ae8f4c37b0ed75bdc96d0fc6a44 Mon Sep 17 00:00:00 2001 |
| From: Jeff Mahoney <jeffm@suse.com> |
| Date: Wed, 2 Apr 2014 14:40:26 -0400 |
| Subject: reiserfs: fix race in readdir |
| |
| From: Jeff Mahoney <jeffm@suse.com> |
| |
| commit 01d8885785a60ae8f4c37b0ed75bdc96d0fc6a44 upstream. |
| |
| jdm-20004 reiserfs_delete_xattrs: Couldn't delete all xattrs (-2) |
| |
| The -ENOENT is due to readdir calling dir_emit on the same entry twice. |
| |
| If the dir_emit callback sleeps and the tree is changed underneath us, |
| we won't be able to trust deh_offset(deh) anymore. We need to save |
| next_pos before we might sleep so we can find the next entry. |
| |
| Signed-off-by: Jeff Mahoney <jeffm@suse.com> |
| Signed-off-by: Jan Kara <jack@suse.cz> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/reiserfs/dir.c | 6 ++++-- |
| 1 file changed, 4 insertions(+), 2 deletions(-) |
| |
| --- a/fs/reiserfs/dir.c |
| +++ b/fs/reiserfs/dir.c |
| @@ -128,6 +128,7 @@ int reiserfs_readdir_dentry(struct dentr |
| char *d_name; |
| off_t d_off; |
| ino_t d_ino; |
| + loff_t cur_pos = deh_offset(deh); |
| |
| if (!de_visible(deh)) |
| /* it is hidden entry */ |
| @@ -200,8 +201,9 @@ int reiserfs_readdir_dentry(struct dentr |
| if (local_buf != small_buf) { |
| kfree(local_buf); |
| } |
| - // next entry should be looked for with such offset |
| - next_pos = deh_offset(deh) + 1; |
| + |
| + /* deh_offset(deh) may be invalid now. */ |
| + next_pos = cur_pos + 1; |
| |
| if (item_moved(&tmp_ih, &path_to_entry)) { |
| goto research; |