Commit b74b1293 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Darrick J. Wong
Browse files

iomap: rework unshare flag 



Instead of another internal flags namespace inside of buffered-io.c,
just pass a UNSHARE hint in the main iomap flags field.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
parent 1b5c1e36

fs/iomap/buffered-io.c

+9 −14
Original line number Diff line number Diff line
@@ -508,10 +508,6 @@ iomap_migrate_page(struct address_space *mapping, struct page *newpage, 
EXPORT_SYMBOL_GPL(iomap_migrate_page);

#endif /* CONFIG_MIGRATION */



enum {

	IOMAP_WRITE_F_UNSHARE		= (1 << 0),

};



static void

iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)

{
@@ -541,7 +537,7 @@ iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff, 
}



static int __iomap_write_begin(struct iomap_iter *iter, loff_t pos,

		unsigned len, int flags, struct page *page)

		unsigned len, struct page *page)

{

	struct iomap *srcmap = iomap_iter_srcmap(iter);

	struct iomap_page *iop = iomap_page_create(iter->inode, page);
@@ -560,13 +556,13 @@ static int __iomap_write_begin(struct iomap_iter *iter, loff_t pos, 
		if (plen == 0)

			break;



		if (!(flags & IOMAP_WRITE_F_UNSHARE) &&

		if (!(iter->flags & IOMAP_UNSHARE) &&

		    (from <= poff || from >= poff + plen) &&

		    (to <= poff || to >= poff + plen))

			continue;



		if (iomap_block_needs_zeroing(iter, block_start)) {

			if (WARN_ON_ONCE(flags & IOMAP_WRITE_F_UNSHARE))

			if (WARN_ON_ONCE(iter->flags & IOMAP_UNSHARE))

				return -EIO;

			zero_user_segments(page, poff, from, to, poff + plen);

		} else {
@@ -596,7 +592,7 @@ static int iomap_write_begin_inline(struct iomap_iter *iter, 
}



static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, unsigned len,

		unsigned flags, struct page **pagep)

		struct page **pagep)

{

	const struct iomap_page_ops *page_ops = iter->iomap.page_ops;

	struct iomap *srcmap = iomap_iter_srcmap(iter);
@@ -628,7 +624,7 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, unsigned len, 
	else if (srcmap->flags & IOMAP_F_BUFFER_HEAD)

		status = __block_write_begin_int(page, pos, len, NULL, srcmap);

	else

		status = __iomap_write_begin(iter, pos, len, flags, page);

		status = __iomap_write_begin(iter, pos, len, page);



	if (unlikely(status))

		goto out_unlock;
@@ -759,7 +755,7 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i) 
			break;

		}



		status = iomap_write_begin(iter, pos, bytes, 0, &page);

		status = iomap_write_begin(iter, pos, bytes, &page);

		if (unlikely(status))

			break;
@@ -836,8 +832,7 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter) 
		unsigned long bytes = min_t(loff_t, PAGE_SIZE - offset, length);

		struct page *page;



		status = iomap_write_begin(iter, pos, bytes,

				IOMAP_WRITE_F_UNSHARE, &page);

		status = iomap_write_begin(iter, pos, bytes, &page);

		if (unlikely(status))

			return status;
@@ -865,7 +860,7 @@ iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, 
		.inode		= inode,

		.pos		= pos,

		.len		= len,

		.flags		= IOMAP_WRITE,

		.flags		= IOMAP_WRITE | IOMAP_UNSHARE,

	};

	int ret;
@@ -882,7 +877,7 @@ static s64 __iomap_zero_iter(struct iomap_iter *iter, loff_t pos, u64 length) 
	unsigned offset = offset_in_page(pos);

	unsigned bytes = min_t(u64, PAGE_SIZE - offset, length);



	status = iomap_write_begin(iter, pos, bytes, 0, &page);

	status = iomap_write_begin(iter, pos, bytes, &page);

	if (status)

		return status;

include/linux/iomap.h

+1 −0
Original line number Diff line number Diff line
@@ -140,6 +140,7 @@ struct iomap_page_ops { 
#define IOMAP_DIRECT		(1 << 4) /* direct I/O */

#define IOMAP_NOWAIT		(1 << 5) /* do not block */

#define IOMAP_OVERWRITE_ONLY	(1 << 6) /* only pure overwrites allowed */

#define IOMAP_UNSHARE		(1 << 7) /* unshare_file_range */



struct iomap_ops {

	/*