Commit 0cf55444 authored Sep 25, 2020 by Matthew Wilcox (Oracle) Committed by Greg Kroah-Hartman Nov 28, 2023

iomap: Set all uptodate bits for an Uptodate page



commit 4595a298d5563cf76c1d852970f162051fd1a7a6 upstream.

For filesystems with block size < page size, we need to set all the
per-block uptodate bits if the page was already uptodate at the time
we create the per-block metadata.  This can happen if the page is
invalidated (eg by a write to drop_caches) but ultimately not removed
from the page cache.

This is a data corruption issue as page writeback skips blocks which
are marked !uptodate.

Fixes: 9dc55f13 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Qian Cai <cai@redhat.com>
Cc: Brian Foster <bfoster@redhat.com>
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 7907729c

fs/iomap.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -109,6 +109,7 @@ static struct iomap_page *
		iomap_page_create(struct inode inode, struct page page)
		{
		struct iomap_page *iop = to_iomap_page(page);
		unsigned int nr_blocks = PAGE_SIZE / i_blocksize(inode);

		if (iop \|\| i_blocksize(inode) == PAGE_SIZE)
		return iop;
		@@ -118,6 +119,8 @@ iomap_page_create(struct inode inode, struct page page)
		atomic_set(&iop->write_count, 0);
		spin_lock_init(&iop->uptodate_lock);
		bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
		if (PageUptodate(page))
		bitmap_fill(iop->uptodate, nr_blocks);

		/*
		* migrate_page_move_mapping() assumes that pages with private data have