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Commit c923258e authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Greg Kroah-Hartman
Browse files

iomap: fix sub-page uptodate handling 



commit 1cea335d1db1ce6ab71b3d2f94a807112b738a0f upstream.

bio completions can race when a page spans more than one file system
block.  Add a spinlock to synchronize marking the page uptodate.

Fixes: 9dc55f13 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
Reported-by: default avatarJan Stancek <jstancek@redhat.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 867fd8d5

fs/iomap.c

+24 −10
Original line number Diff line number Diff line
@@ -116,6 +116,7 @@ iomap_page_create(struct inode *inode, struct page *page) 
	iop = kmalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);

	atomic_set(&iop->read_count, 0);

	atomic_set(&iop->write_count, 0);

	spin_lock_init(&iop->uptodate_lock);

	bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);



	/*
@@ -204,25 +205,38 @@ iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, 
}



static void

iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)

iomap_iop_set_range_uptodate(struct page *page, unsigned off, unsigned len)

{

	struct iomap_page *iop = to_iomap_page(page);

	struct inode *inode = page->mapping->host;

	unsigned first = off >> inode->i_blkbits;

	unsigned last = (off + len - 1) >> inode->i_blkbits;

	unsigned int i;

	bool uptodate = true;

	unsigned long flags;

	unsigned int i;



	if (iop) {

	spin_lock_irqsave(&iop->uptodate_lock, flags);

	for (i = 0; i < PAGE_SIZE / i_blocksize(inode); i++) {

		if (i >= first && i <= last)

			set_bit(i, iop->uptodate);

		else if (!test_bit(i, iop->uptodate))

			uptodate = false;

	}



	if (uptodate)

		SetPageUptodate(page);

	spin_unlock_irqrestore(&iop->uptodate_lock, flags);

}



	if (uptodate && !PageError(page))

static void

iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)

{

	if (PageError(page))

		return;



	if (page_has_private(page))

		iomap_iop_set_range_uptodate(page, off, len);

	else

		SetPageUptodate(page);

}

include/linux/iomap.h

+1 −0
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ struct iomap_ops { 
struct iomap_page {

	atomic_t		read_count;

	atomic_t		write_count;

	spinlock_t		uptodate_lock;

	DECLARE_BITMAP(uptodate, PAGE_SIZE / 512);

};