From: Greg KH <gregkh@suse.de>
To: linux-kernel@vger.kernel.org, stable@kernel.org
Cc: stable-review@kernel.org, torvalds@linux-foundation.org,
akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk,
Curt Wohlgemuth <curtw@google.com>,
"Theodore Tso" <tytso@mit.edu>
Subject: [106/165] ext4: Fix possible lost inode write in no journal mode
Date: Fri, 30 Jul 2010 10:15:34 -0700 [thread overview]
Message-ID: <20100730171509.206431183@clark.site> (raw)
In-Reply-To: <20100730171550.GA1299@kroah.com
2.6.32-stable review patch. If anyone has any objections, please let us know.
------------------
commit 8b472d739b2ddd8ab7fb278874f696cd95b25a5e upstream (as of v2.6.34-rc6)
In the no-journal case, ext4_write_inode() will fetch the bh and call
sync_dirty_buffer() on it. However, if the bh has already been
written and the bh reclaimed for some other purpose, AND if the inode
is the only one in the inode table block in use, then
ext4_get_inode_loc() will not read the inode table block from disk,
but as an optimization, fill the block with zero's assuming that its
caller will copy in the on-disk version of the inode. This is not
done by ext4_write_inode(), so the contents of the inode can simply
get lost. The fix is to use __ext4_get_inode_loc() with in_mem set to
0, instead of ext4_get_inode_loc(). Long term the API needs to be
fixed so it's obvious why latter is not safe.
Addresses-Google-Bug: #2526446
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
fs/ext4/inode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5260,7 +5260,7 @@ int ext4_write_inode(struct inode *inode
} else {
struct ext4_iloc iloc;
- err = ext4_get_inode_loc(inode, &iloc);
+ err = __ext4_get_inode_loc(inode, &iloc, 0);
if (err)
return err;
if (wait)
reply other threads:[~2010-07-30 17:32 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100730171509.206431183@clark.site \
--to=gregkh@suse.de \
--cc=akpm@linux-foundation.org \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=curtw@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=stable-review@kernel.org \
--cc=stable@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox