From: Anju T Sudhakar <anju@linux.vnet.ibm.com>
To: hch@infradead.org, darrick.wong@oracle.com
Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, willy@infradead.org,
riteshh@linux.ibm.com, anju@linux.vnet.ibm.com
Subject: [PATCH] iomap: Fix the write_count in iomap_add_to_ioend().
Date: Wed, 19 Aug 2020 15:58:41 +0530 [thread overview]
Message-ID: <20200819102841.481461-1-anju@linux.vnet.ibm.com> (raw)
From: Ritesh Harjani <riteshh@linux.ibm.com>
__bio_try_merge_page() may return same_page = 1 and merged = 0.
This could happen when bio->bi_iter.bi_size + len > UINT_MAX.
Handle this case in iomap_add_to_ioend() by incrementing write_count.
This scenario mostly happens where we have too much dirty data accumulated.
w/o the patch we hit below kernel warning,
WARNING: CPU: 18 PID: 5130 at fs/iomap/buffered-io.c:74 iomap_page_release+0x120/0x150
CPU: 18 PID: 5130 Comm: fio Kdump: loaded Tainted: G W 5.8.0-rc3 #6
Call Trace:
__remove_mapping+0x154/0x320 (unreliable)
iomap_releasepage+0x80/0x180
try_to_release_page+0x94/0xe0
invalidate_inode_page+0xc8/0x110
invalidate_mapping_pages+0x1dc/0x540
generic_fadvise+0x3c8/0x450
xfs_file_fadvise+0x2c/0xe0 [xfs]
vfs_fadvise+0x3c/0x60
ksys_fadvise64_64+0x68/0xe0
sys_fadvise64+0x28/0x40
system_call_exception+0xf8/0x1c0
system_call_common+0xf0/0x278
Reported-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
---
fs/iomap/buffered-io.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index bcfc288dba3f..4e8062279e66 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1332,10 +1332,12 @@ iomap_add_to_ioend(struct inode *inode, loff_t offset, struct page *page,
merged = __bio_try_merge_page(wpc->ioend->io_bio, page, len, poff,
&same_page);
- if (iop && !same_page)
+ if (iop && merged && !same_page)
atomic_inc(&iop->write_count);
if (!merged) {
+ if (iop)
+ atomic_inc(&iop->write_count);
if (bio_full(wpc->ioend->io_bio, len)) {
wpc->ioend->io_bio =
iomap_chain_bio(wpc->ioend->io_bio);
--
2.25.4
next reply other threads:[~2020-08-19 10:29 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-19 10:28 Anju T Sudhakar [this message]
2020-08-20 23:11 ` [PATCH] iomap: Fix the write_count in iomap_add_to_ioend() Dave Chinner
2020-08-21 4:45 ` Ritesh Harjani
2020-08-21 6:00 ` Christoph Hellwig
2020-08-21 9:09 ` Ritesh Harjani
2020-08-21 21:53 ` Dave Chinner
2020-08-22 13:13 ` Christoph Hellwig
2020-08-24 14:28 ` Brian Foster
2020-08-24 15:04 ` Christoph Hellwig
2020-08-24 15:48 ` Brian Foster
2020-08-25 0:42 ` Dave Chinner
2020-08-25 14:49 ` Brian Foster
2020-08-31 4:01 ` Ming Lei
2020-08-31 14:35 ` Brian Foster
2020-09-16 0:12 ` Darrick J. Wong
2020-09-16 8:45 ` Christoph Hellwig
2020-09-16 13:07 ` Brian Foster
2020-09-17 8:04 ` Christoph Hellwig
2020-09-17 10:42 ` Brian Foster
2020-09-17 14:48 ` Christoph Hellwig
2020-09-17 21:33 ` Darrick J. Wong
2020-09-17 23:13 ` Ming Lei
2020-08-21 6:01 ` Christoph Hellwig
2020-08-21 6:07 ` Christoph Hellwig
2020-08-21 8:53 ` Ritesh Harjani
2020-08-21 14:49 ` Jens Axboe
2020-08-21 13:31 ` Matthew Wilcox
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