From: Andreas Gruenbacher <agruenba@redhat.com>
To: Christoph Hellwig <hch@lst.de>, "Darrick J . Wong" <djwong@kernel.org>
Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
cluster-devel@redhat.com,
Andreas Gruenbacher <agruenba@redhat.com>,
stable@vger.kernel.org
Subject: [5.15 REGRESSION v2] iomap: Fix inline extent handling in iomap_readpage
Date: Thu, 11 Nov 2021 17:17:14 +0100 [thread overview]
Message-ID: <20211111161714.584718-1-agruenba@redhat.com> (raw)
Before commit 740499c78408 ("iomap: fix the iomap_readpage_actor return
value for inline data"), when hitting an IOMAP_INLINE extent,
iomap_readpage_actor would report having read the entire page. Since
then, it only reports having read the inline data (iomap->length).
This will force iomap_readpage into another iteration, and the
filesystem will report an unaligned hole after the IOMAP_INLINE extent.
But iomap_readpage_actor (now iomap_readpage_iter) isn't prepared to
deal with unaligned extents, it will get things wrong on filesystems
with a block size smaller than the page size, and we'll eventually run
into the following warning in iomap_iter_advance:
WARN_ON_ONCE(iter->processed > iomap_length(iter));
Fix that by changing iomap_readpage_iter to return 0 when hitting an
inline extent; this will cause iomap_iter to stop immediately.
To fix readahead as well, change iomap_readahead_iter to pass on
iomap_readpage_iter return values less than or equal to zero.
Fixes: 740499c78408 ("iomap: fix the iomap_readpage_actor return value for inline data")
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
fs/iomap/buffered-io.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 1753c26c8e76..fe10d8a30f6b 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -256,8 +256,13 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
unsigned poff, plen;
sector_t sector;
- if (iomap->type == IOMAP_INLINE)
- return min(iomap_read_inline_data(iter, page), length);
+ if (iomap->type == IOMAP_INLINE) {
+ loff_t ret = iomap_read_inline_data(iter, page);
+
+ if (ret < 0)
+ return ret;
+ return 0;
+ }
/* zero post-eof blocks as the page may be mapped */
iop = iomap_page_create(iter->inode, page);
@@ -370,6 +375,8 @@ static loff_t iomap_readahead_iter(const struct iomap_iter *iter,
ctx->cur_page_in_bio = false;
}
ret = iomap_readpage_iter(iter, ctx, done);
+ if (ret <= 0)
+ return ret;
}
return done;
--
2.31.1
next reply other threads:[~2021-11-11 16:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-11 16:17 Andreas Gruenbacher [this message]
2021-11-12 5:44 ` [5.15 REGRESSION v2] iomap: Fix inline extent handling in iomap_readpage Christoph Hellwig
2021-11-17 5:33 ` Darrick J. Wong
2021-11-17 5:52 ` Gao Xiang
2021-11-17 10:24 ` Andreas Gruenbacher
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