All of lore.kernel.org
 help / color / mirror / Atom feed
From: Hou Tao <houtao1@huawei.com>
To: <tytso@mit.edu>, <adilger.kernel@dilger.ca>,
	<harshadshirwadkar@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Subject: Re: [PATCH] ext4: limit the number of blocks in one ADD_RANGE TLV
Date: Mon, 30 Aug 2021 15:52:11 +0800	[thread overview]
Message-ID: <0129a56a-2d45-5558-9125-0b3408104b7d@huawei.com> (raw)
In-Reply-To: <20210820044505.474318-1-houtao1@huawei.com>

ping ?

On 8/20/2021 12:45 PM, Hou Tao wrote:
> Now EXT4_FC_TAG_ADD_RANGE uses ext4_extent to track the
> newly-added blocks, but the limit on the max value of
> ee_len field is ignored, and it can lead to BUG_ON as
> shown below when running command "fallocate -l 128M file"
> on a fast_commit-enabled fs:
>
>   kernel BUG at fs/ext4/ext4_extents.h:199!
>   invalid opcode: 0000 [#1] SMP PTI
>   CPU: 3 PID: 624 Comm: fallocate Not tainted 5.14.0-rc6+ #1
>   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
>   RIP: 0010:ext4_fc_write_inode_data+0x1f3/0x200
>   Call Trace:
>    ? ext4_fc_write_inode+0xf2/0x150
>    ext4_fc_commit+0x93b/0xa00
>    ? ext4_fallocate+0x1ad/0x10d0
>    ext4_sync_file+0x157/0x340
>    ? ext4_sync_file+0x157/0x340
>    vfs_fsync_range+0x49/0x80
>    do_fsync+0x3d/0x70
>    __x64_sys_fsync+0x14/0x20
>    do_syscall_64+0x3b/0xc0
>    entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> Simply fixing it by limiting the number of blocks
> in one EXT4_FC_TAG_ADD_RANGE TLV.
>
> Fixes: aa75f4d3daae ("ext4: main fast-commit commit path")
> Signed-off-by: Hou Tao <houtao1@huawei.com>
> ---
>  fs/ext4/fast_commit.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
> index e8195229c252..782d05a3f97a 100644
> --- a/fs/ext4/fast_commit.c
> +++ b/fs/ext4/fast_commit.c
> @@ -893,6 +893,12 @@ static int ext4_fc_write_inode_data(struct inode *inode, u32 *crc)
>  					    sizeof(lrange), (u8 *)&lrange, crc))
>  				return -ENOSPC;
>  		} else {
> +			unsigned int max = (map.m_flags & EXT4_MAP_UNWRITTEN) ?
> +				EXT_UNWRITTEN_MAX_LEN : EXT_INIT_MAX_LEN;
> +
> +			/* Limit the number of blocks in one extent */
> +			map.m_len = min(max, map.m_len);
> +
>  			fc_ext.fc_ino = cpu_to_le32(inode->i_ino);
>  			ex = (struct ext4_extent *)&fc_ext.fc_ex;
>  			ex->ee_block = cpu_to_le32(map.m_lblk);

  reply	other threads:[~2021-08-30  7:52 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-20  4:45 [PATCH] ext4: limit the number of blocks in one ADD_RANGE TLV Hou Tao
2021-08-30  7:52 ` Hou Tao [this message]
2021-09-07 11:21   ` Hou Tao
2021-09-09 16:51     ` harshad shirwadkar
2021-09-09 17:10 ` Theodore Ts'o

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=0129a56a-2d45-5558-9125-0b3408104b7d@huawei.com \
    --to=houtao1@huawei.com \
    --cc=adilger.kernel@dilger.ca \
    --cc=harshadshirwadkar@gmail.com \
    --cc=linux-ext4@vger.kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.