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From: "Pankaj Raghav (Samsung)" <kernel@pankajraghav.com>
To: willy@infradead.org, djwong@kernel.org, brauner@kernel.org,
	david@fromorbit.com, chandan.babu@oracle.com,
	akpm@linux-foundation.org
Cc: linux-fsdevel@vger.kernel.org, hare@suse.de,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	linux-xfs@vger.kernel.org, mcgrof@kernel.org,
	gost.dev@samsung.com, p.raghav@samsung.com
Subject: [PATCH v4 07/11] iomap: fix iomap_dio_zero() for fs bs > system page size
Date: Thu, 25 Apr 2024 13:37:42 +0200	[thread overview]
Message-ID: <20240425113746.335530-8-kernel@pankajraghav.com> (raw)
In-Reply-To: <20240425113746.335530-1-kernel@pankajraghav.com>

From: Pankaj Raghav <p.raghav@samsung.com>

iomap_dio_zero() will pad a fs block with zeroes if the direct IO size
< fs block size. iomap_dio_zero() has an implicit assumption that fs block
size < page_size. This is true for most filesystems at the moment.

If the block size > page size, this will send the contents of the page
next to zero page(as len > PAGE_SIZE) to the underlying block device,
causing FS corruption.

iomap is a generic infrastructure and it should not make any assumptions
about the fs block size and the page size of the system.

Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/iomap/direct-io.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index f3b43d223a46..5f481068de5b 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -239,14 +239,23 @@ static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio,
 	struct page *page = ZERO_PAGE(0);
 	struct bio *bio;
 
-	bio = iomap_dio_alloc_bio(iter, dio, 1, REQ_OP_WRITE | REQ_SYNC | REQ_IDLE);
+	WARN_ON_ONCE(len > (BIO_MAX_VECS * PAGE_SIZE));
+
+	bio = iomap_dio_alloc_bio(iter, dio, BIO_MAX_VECS,
+				  REQ_OP_WRITE | REQ_SYNC | REQ_IDLE);
 	fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits,
 				  GFP_KERNEL);
+
 	bio->bi_iter.bi_sector = iomap_sector(&iter->iomap, pos);
 	bio->bi_private = dio;
 	bio->bi_end_io = iomap_dio_bio_end_io;
 
-	__bio_add_page(bio, page, len, 0);
+	while (len) {
+		unsigned int io_len = min_t(unsigned int, len, PAGE_SIZE);
+
+		__bio_add_page(bio, page, io_len, 0);
+		len -= io_len;
+	}
 	iomap_dio_submit_bio(iter, dio, bio, pos);
 }
 
-- 
2.34.1


  parent reply	other threads:[~2024-04-25 11:47 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-25 11:37 [PATCH v4 00/11] enable bs > ps in XFS Pankaj Raghav (Samsung)
2024-04-25 11:37 ` [PATCH v4 01/11] readahead: rework loop in page_cache_ra_unbounded() Pankaj Raghav (Samsung)
2024-04-25 11:37 ` [PATCH v4 02/11] fs: Allow fine-grained control of folio sizes Pankaj Raghav (Samsung)
2024-04-25 18:07   ` Hannes Reinecke
2024-04-26 15:09   ` Darrick J. Wong
2024-04-25 11:37 ` [PATCH v4 03/11] filemap: allocate mapping_min_order folios in the page cache Pankaj Raghav (Samsung)
2024-04-25 19:04   ` Hannes Reinecke
2024-04-26 15:12   ` Darrick J. Wong
2024-04-28 20:59     ` Pankaj Raghav (Samsung)
2024-04-25 11:37 ` [PATCH v4 04/11] readahead: allocate folios with mapping_min_order in readahead Pankaj Raghav (Samsung)
2024-04-25 18:53   ` Matthew Wilcox
2024-04-25 11:37 ` [PATCH v4 05/11] mm: do not split a folio if it has minimum folio order requirement Pankaj Raghav (Samsung)
2024-04-25 20:10   ` Matthew Wilcox
2024-04-26  0:47     ` Luis Chamberlain
2024-04-26 23:46       ` Luis Chamberlain
2024-04-28  0:57         ` Luis Chamberlain
2024-04-29  3:56           ` Luis Chamberlain
2024-04-29 14:29             ` Zi Yan
2024-04-30  0:31               ` Luis Chamberlain
2024-04-30  0:49                 ` Luis Chamberlain
2024-04-30  2:43                 ` Zi Yan
2024-04-30 19:27                   ` Luis Chamberlain
2024-05-01  4:13                     ` Matthew Wilcox
2024-05-01 14:28                       ` Matthew Wilcox
2024-04-26 15:49     ` Pankaj Raghav (Samsung)
2024-04-25 11:37 ` [PATCH v4 06/11] filemap: cap PTE range to be created to i_size in folio_map_range() Pankaj Raghav (Samsung)
2024-04-25 20:24   ` Matthew Wilcox
2024-04-26 12:54     ` Pankaj Raghav (Samsung)
2024-04-25 11:37 ` Pankaj Raghav (Samsung) [this message]
2024-04-26  6:22   ` [PATCH v4 07/11] iomap: fix iomap_dio_zero() for fs bs > system page size Christoph Hellwig
2024-04-26 11:43     ` Pankaj Raghav (Samsung)
2024-04-27  5:12       ` Christoph Hellwig
2024-04-29 21:02         ` Pankaj Raghav (Samsung)
2024-04-27  3:26     ` Matthew Wilcox
2024-04-27  4:52       ` Christoph Hellwig
2024-04-25 11:37 ` [PATCH v4 08/11] xfs: use kvmalloc for xattr buffers Pankaj Raghav (Samsung)
2024-04-26 15:18   ` Darrick J. Wong
2024-04-28 21:06     ` Pankaj Raghav (Samsung)
2024-04-25 11:37 ` [PATCH v4 09/11] xfs: expose block size in stat Pankaj Raghav (Samsung)
2024-04-26 15:15   ` Darrick J. Wong
2024-04-25 11:37 ` [PATCH v4 10/11] xfs: make the calculation generic in xfs_sb_validate_fsb_count() Pankaj Raghav (Samsung)
2024-04-26 15:16   ` Darrick J. Wong
2024-04-25 11:37 ` [PATCH v4 11/11] xfs: enable block size larger than page size support Pankaj Raghav (Samsung)
2024-04-26 15:18   ` Darrick J. Wong
2024-04-27  4:42 ` [PATCH v4 00/11] enable bs > ps in XFS Ritesh Harjani
2024-04-27  5:05   ` Darrick J. Wong
2024-04-29 20:39   ` Pankaj Raghav (Samsung)

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