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From: "Pankaj Raghav (Samsung)" <kernel@pankajraghav.com>
To: willy@infradead.org, linux-xfs@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
Cc: gost.dev@samsung.com, chandan.babu@oracle.com, hare@suse.de,
	mcgrof@kernel.org, djwong@kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, david@fromorbit.com,
	akpm@linux-foundation.org, Pankaj Raghav <p.raghav@samsung.com>
Subject: [PATCH v3 08/11] iomap: fix iomap_dio_zero() for fs bs > system page size
Date: Wed, 13 Mar 2024 18:02:50 +0100	[thread overview]
Message-ID: <20240313170253.2324812-9-kernel@pankajraghav.com> (raw)
In-Reply-To: <20240313170253.2324812-1-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 bcd3f8cf5ea4..04f6c5548136 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);
 }
 
-- 
2.43.0


  parent reply	other threads:[~2024-03-13 17:03 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-13 17:02 [PATCH v3 00/11] enable bs > ps in XFS Pankaj Raghav (Samsung)
2024-03-13 17:02 ` [PATCH v3 01/11] mm: Support order-1 folios in the page cache Pankaj Raghav (Samsung)
2024-03-13 17:02 ` [PATCH v3 02/11] fs: Allow fine-grained control of folio sizes Pankaj Raghav (Samsung)
2024-03-25 18:29   ` Matthew Wilcox
2024-03-26  8:44     ` Pankaj Raghav (Samsung)
2024-03-13 17:02 ` [PATCH v3 03/11] filemap: allocate mapping_min_order folios in the page cache Pankaj Raghav (Samsung)
2024-03-15 13:21   ` Pankaj Raghav (Samsung)
2024-03-13 17:02 ` [PATCH v3 04/11] readahead: rework loop in page_cache_ra_unbounded() Pankaj Raghav (Samsung)
2024-03-25 18:41   ` Matthew Wilcox
2024-03-26  8:56     ` Pankaj Raghav (Samsung)
2024-03-26  9:39     ` Hannes Reinecke
2024-03-26  9:44       ` Pankaj Raghav
2024-03-26 10:00         ` Hannes Reinecke
2024-03-26 10:06           ` Pankaj Raghav
2024-03-26 10:55             ` Hannes Reinecke
2024-03-26 13:41               ` Pankaj Raghav (Samsung)
2024-03-26 15:11     ` Pankaj Raghav (Samsung)
2024-03-13 17:02 ` [PATCH v3 05/11] readahead: allocate folios with mapping_min_order in readahead Pankaj Raghav (Samsung)
2024-03-25 19:00   ` Matthew Wilcox
2024-03-26 13:08     ` Pankaj Raghav (Samsung)
2024-04-22 11:03     ` Pankaj Raghav (Samsung)
2024-03-13 17:02 ` [PATCH v3 06/11] readahead: round up file_ra_state->ra_pages to mapping_min_nrpages Pankaj Raghav (Samsung)
2024-03-13 17:02 ` [PATCH v3 07/11] mm: do not split a folio if it has minimum folio order requirement Pankaj Raghav (Samsung)
2024-03-25 19:06   ` Matthew Wilcox
2024-03-26 16:10     ` Pankaj Raghav (Samsung)
2024-03-26 16:23       ` Zi Yan
2024-03-26 16:33         ` Pankaj Raghav
2024-03-26 16:38           ` Zi Yan
2024-03-13 17:02 ` Pankaj Raghav (Samsung) [this message]
2024-03-13 17:02 ` [PATCH v3 09/11] xfs: expose block size in stat Pankaj Raghav (Samsung)
2024-03-13 17:02 ` [PATCH v3 10/11] xfs: make the calculation generic in xfs_sb_validate_fsb_count() Pankaj Raghav (Samsung)
2024-03-25 19:15   ` Matthew Wilcox
2024-03-26  9:53     ` Pankaj Raghav (Samsung)
2024-03-13 17:02 ` [PATCH v3 11/11] xfs: enable block size larger than page size support Pankaj Raghav (Samsung)
2024-03-25 19:19 ` [PATCH v3 00/11] enable bs > ps in XFS Matthew Wilcox
2024-03-26  9:53   ` Hannes Reinecke
2024-03-26 15:06     ` Pankaj Raghav
2024-03-26 14:54   ` Pankaj Raghav (Samsung)

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