2008-12-03 19:57:57

by Greg KH

[permalink] [raw]
Subject: [patch 092/104] ext4: Fix duplicate entries returned from getdents() system call

2.6.27-stable review patch. If anyone has any objections, please let us know.

From: "Theodore Ts'o" <[email protected]>

(cherry picked from commit 3c37fc86d20fe35be656f070997d62f75c2e4874)

Fix a regression caused by commit d0156417, "ext4: fix ext4_dx_readdir
hash collision handling", where deleting files in a large directory
(requiring more than one getdents system call), results in some
filenames being returned twice. This was caused by a failure to
update info->curr_hash and info->curr_minor_hash, so that if the
directory had gotten modified since the last getdents() system call
(as would be the case if the user is running "rm -r" or "git clean"),
a directory entry would get returned twice to the userspace.

Signed-off-by: "Theodore Ts'o" <[email protected]>

This patch fixes the bug reported by Markus Trippelsdorf at:

Signed-off-by: "Theodore Ts'o" <[email protected]>
Tested-by: Markus Trippelsdorf <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

fs/ext4/dir.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)

--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -458,17 +458,8 @@ static int ext4_dx_readdir(struct file *
if (info->extra_fname) {
if (call_filldir(filp, dirent, filldir, info->extra_fname))
goto finished;
info->extra_fname = NULL;
- info->curr_node = rb_next(info->curr_node);
- if (!info->curr_node) {
- if (info->next_hash == ~0) {
- filp->f_pos = EXT4_HTREE_EOF;
- goto finished;
- }
- info->curr_hash = info->next_hash;
- info->curr_minor_hash = 0;
- }
+ goto next_node;
} else if (!info->curr_node)
info->curr_node = rb_first(&info->root);

@@ -500,9 +491,14 @@ static int ext4_dx_readdir(struct file *
info->curr_minor_hash = fname->minor_hash;
if (call_filldir(filp, dirent, filldir, fname))