From: "Darrick J. Wong" <djwong@kernel.org>
To: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: linux-xfs@vger.kernel.org, Dave Chinner <david@fromorbit.com>,
Christoph Hellwig <hch@infradead.org>,
Ojaswin Mujoo <ojaswin@linux.ibm.com>
Subject: Re: [PATCHv4 1/1] xfs: Add cond_resched to block unmap range and reflink remap path
Date: Tue, 7 May 2024 14:11:34 -0700 [thread overview]
Message-ID: <20240507211134.GV360919@frogsfrogsfrogs> (raw)
In-Reply-To: <3e1986b79faa3307059ce9d57ff3e44c0d85fe4f.1715073983.git.ritesh.list@gmail.com>
On Tue, May 07, 2024 at 03:06:55PM +0530, Ritesh Harjani (IBM) wrote:
> An async dio write to a sparse file can generate a lot of extents
> and when we unlink this file (using rm), the kernel can be busy in umapping
> and freeing those extents as part of transaction processing.
>
> Similarly xfs reflink remapping path can also iterate over a million
> extent entries in xfs_reflink_remap_blocks().
>
> Since we can busy loop in these two functions, so let's add cond_resched()
> to avoid softlockup messages like these.
>
> watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [kworker/1:0:82435]
> CPU: 1 PID: 82435 Comm: kworker/1:0 Tainted: G S L 6.9.0-rc5-0-default #1
> Workqueue: xfs-inodegc/sda2 xfs_inodegc_worker
> NIP [c000000000beea10] xfs_extent_busy_trim+0x100/0x290
> LR [c000000000bee958] xfs_extent_busy_trim+0x48/0x290
> Call Trace:
> xfs_alloc_get_rec+0x54/0x1b0 (unreliable)
> xfs_alloc_compute_aligned+0x5c/0x144
> xfs_alloc_ag_vextent_size+0x238/0x8d4
> xfs_alloc_fix_freelist+0x540/0x694
> xfs_free_extent_fix_freelist+0x84/0xe0
> __xfs_free_extent+0x74/0x1ec
> xfs_extent_free_finish_item+0xcc/0x214
> xfs_defer_finish_one+0x194/0x388
> xfs_defer_finish_noroll+0x1b4/0x5c8
> xfs_defer_finish+0x2c/0xc4
> xfs_bunmapi_range+0xa4/0x100
> xfs_itruncate_extents_flags+0x1b8/0x2f4
> xfs_inactive_truncate+0xe0/0x124
> xfs_inactive+0x30c/0x3e0
> xfs_inodegc_worker+0x140/0x234
> process_scheduled_works+0x240/0x57c
> worker_thread+0x198/0x468
> kthread+0x138/0x140
> start_kernel_thread+0x14/0x18
>
> run fstests generic/175 at 2024-02-02 04:40:21
> [ C17] watchdog: BUG: soft lockup - CPU#17 stuck for 23s! [xfs_io:7679]
> watchdog: BUG: soft lockup - CPU#17 stuck for 23s! [xfs_io:7679]
> CPU: 17 PID: 7679 Comm: xfs_io Kdump: loaded Tainted: G X 6.4.0
> NIP [c008000005e3ec94] xfs_rmapbt_diff_two_keys+0x54/0xe0 [xfs]
> LR [c008000005e08798] xfs_btree_get_leaf_keys+0x110/0x1e0 [xfs]
> Call Trace:
> 0xc000000014107c00 (unreliable)
> __xfs_btree_updkeys+0x8c/0x2c0 [xfs]
> xfs_btree_update_keys+0x150/0x170 [xfs]
> xfs_btree_lshift+0x534/0x660 [xfs]
> xfs_btree_make_block_unfull+0x19c/0x240 [xfs]
> xfs_btree_insrec+0x4e4/0x630 [xfs]
> xfs_btree_insert+0x104/0x2d0 [xfs]
> xfs_rmap_insert+0xc4/0x260 [xfs]
> xfs_rmap_map_shared+0x228/0x630 [xfs]
> xfs_rmap_finish_one+0x2d4/0x350 [xfs]
> xfs_rmap_update_finish_item+0x44/0xc0 [xfs]
> xfs_defer_finish_noroll+0x2e4/0x740 [xfs]
> __xfs_trans_commit+0x1f4/0x400 [xfs]
> xfs_reflink_remap_extent+0x2d8/0x650 [xfs]
> xfs_reflink_remap_blocks+0x154/0x320 [xfs]
> xfs_file_remap_range+0x138/0x3a0 [xfs]
> do_clone_file_range+0x11c/0x2f0
> vfs_clone_file_range+0x60/0x1c0
> ioctl_file_clone+0x78/0x140
> sys_ioctl+0x934/0x1270
> system_call_exception+0x158/0x320
> system_call_vectored_common+0x15c/0x2ec
>
> Cc: Ojaswin Mujoo <ojaswin@linux.ibm.com>
> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
LGTM,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
--D
> ---
> fs/xfs/libxfs/xfs_bmap.c | 1 +
> fs/xfs/xfs_reflink.c | 1 +
> 2 files changed, 2 insertions(+)
>
> diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> index 656c95a22f2e..44d5381bc66f 100644
> --- a/fs/xfs/libxfs/xfs_bmap.c
> +++ b/fs/xfs/libxfs/xfs_bmap.c
> @@ -6354,6 +6354,7 @@ xfs_bunmapi_range(
> error = xfs_defer_finish(tpp);
> if (error)
> goto out;
> + cond_resched();
> }
> out:
> return error;
> diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> index 7da0e8f961d3..5f26a608bc09 100644
> --- a/fs/xfs/xfs_reflink.c
> +++ b/fs/xfs/xfs_reflink.c
> @@ -1417,6 +1417,7 @@ xfs_reflink_remap_blocks(
> destoff += imap.br_blockcount;
> len -= imap.br_blockcount;
> remapped_len += imap.br_blockcount;
> + cond_resched();
> }
>
> if (error)
> --
> 2.44.0
>
>
prev parent reply other threads:[~2024-05-07 21:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 9:36 [PATCHv4 0/1] xfs: soft lockups in unmapping and reflink remapping path Ritesh Harjani (IBM)
2024-05-07 9:36 ` [PATCHv4 1/1] xfs: Add cond_resched to block unmap range and reflink remap path Ritesh Harjani (IBM)
2024-05-07 21:11 ` Darrick J. Wong [this message]
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=20240507211134.GV360919@frogsfrogsfrogs \
--to=djwong@kernel.org \
--cc=david@fromorbit.com \
--cc=hch@infradead.org \
--cc=linux-xfs@vger.kernel.org \
--cc=ojaswin@linux.ibm.com \
--cc=ritesh.list@gmail.com \
/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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).