From: Jan Kara <jack@suse.cz>
To: Artem Blagodarenko <artem.blagodarenko@gmail.com>
Cc: linux-ext4@vger.kernel.org, adilger.kernel@dilger.ca,
Denis Lukianov <denis@voxelsoft.com>
Subject: Re: [PATCH] ext4: fix directory index node split corruption
Date: Wed, 4 Aug 2021 17:15:35 +0200 [thread overview]
Message-ID: <20210804151535.GG4578@quack2.suse.cz> (raw)
In-Reply-To: <20210730182403.3254365-1-artem.blagodarenko@gmail.com>
On Fri 30-07-21 14:24:03, Artem Blagodarenko wrote:
> I send patch whose author is Denis Lukianov <denis@voxelsoft.com>
> His messages can't reach this list somehow.
> I only rebased it ontop of master's HEAD and tested that it fixes
> the problem and reviewed.
>
> ----
>
> Following commit b5776e7, a trivial sequential write of empty files to
> an empty ext4 file system (with large_dir enabled) fails after just
> over 26 million files. Depending on luck, file creation will give error
> EEXIST or EUCLEAN.
>
> Commit b5776e7 fixed the no-restart condition so that
> ext4_handle_dirty_dx_node is always called, but it also broke the
> restart condition. This is because when restart=1, the original
> implementation correctly skipped do_split() but b5776e7 clobbered the
> "if(restart)goto journal_error;" logic.
>
> This complementary change protects do_split() from restart condition,
> making it safe from both current and future ordering of goto statements
> in earlier sections of the code.
>
> Tested on 5.11.20 with handy testing script:
>
> i = 0
> while i <= 32000000:
> print (i)
> with open('tmpmnt/%d' % i, 'wb') as fout:
> i += 1
>
> Google-Bug-Id: 176345532
> Fixes: b5776e7 ("ext4: fix potential htree index checksum corruption")
Please use 12 characters from git commit when identifying it (7 characters
is likely to become non-unique). Otherwise the fix looks good so feel free
to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Also I think you should include Ted in 'To' or 'CC' to make it more likely
he sees the patch.
Honza
> Signed-off-by: Denis Lukianov <denis@voxelsoft.com>
> Signed-off-by: Artem Blagodarenko <artem.blagodarenko@gmail.com>
> ---
> fs/ext4/namei.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
> index 5fd56f616cf0..0bbff03d4167 100644
> --- a/fs/ext4/namei.c
> +++ b/fs/ext4/namei.c
> @@ -2542,13 +2542,16 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
> goto journal_error;
> }
> }
> - de = do_split(handle, dir, &bh, frame, &fname->hinfo);
> - if (IS_ERR(de)) {
> - err = PTR_ERR(de);
> + if (!restart) {
> + de = do_split(handle, dir, &bh, frame, &fname->hinfo);
> + if (IS_ERR(de)) {
> + err = PTR_ERR(de);
> + goto cleanup;
> + }
> + err = add_dirent_to_buf(handle, fname, dir, inode, de,
> +bh);
> goto cleanup;
> }
> - err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
> - goto cleanup;
>
> journal_error:
> ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
> --
> 2.18.4
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
prev parent reply other threads:[~2021-08-04 15:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-30 18:24 [PATCH] ext4: fix directory index node split corruption Artem Blagodarenko
2021-08-04 15:15 ` Jan Kara [this message]
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