Commit b405435b authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Darrick J. Wong
Browse files

iomap: Support inline data with block size < page size 



Remove the restriction that inline data must start on a page boundary
in a file.  This allows, for example, the first 2KiB to be stored out
of line and the trailing 30 bytes to be stored inline.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
parent 69f4a26c

fs/iomap/buffered-io.c

+16 −18
Original line number Diff line number Diff line
@@ -209,28 +209,26 @@ static int iomap_read_inline_data(struct inode *inode, struct page *page, 
		struct iomap *iomap)

{

	size_t size = i_size_read(inode) - iomap->offset;

	size_t poff = offset_in_page(iomap->offset);

	void *addr;



	if (PageUptodate(page))

		return 0;

		return PAGE_SIZE - poff;



	/* inline data must start page aligned in the file */

	if (WARN_ON_ONCE(offset_in_page(iomap->offset)))

		return -EIO;

	if (WARN_ON_ONCE(size > PAGE_SIZE -

			 offset_in_page(iomap->inline_data)))

		return -EIO;

	if (WARN_ON_ONCE(size > iomap->length))

		return -EIO;

	if (WARN_ON_ONCE(page_has_private(page)))

		return -EIO;

	if (poff > 0)

		iomap_page_create(inode, page);



	addr = kmap_atomic(page);

	addr = kmap_atomic(page) + poff;

	memcpy(addr, iomap->inline_data, size);

	memset(addr + size, 0, PAGE_SIZE - size);

	memset(addr + size, 0, PAGE_SIZE - poff - size);

	kunmap_atomic(addr);

	SetPageUptodate(page);

	return 0;

	iomap_set_range_uptodate(page, poff, PAGE_SIZE - poff);

	return PAGE_SIZE - poff;

}



static inline bool iomap_block_needs_zeroing(struct inode *inode,
@@ -252,13 +250,8 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, 
	unsigned poff, plen;

	sector_t sector;



	if (iomap->type == IOMAP_INLINE) {

		int ret = iomap_read_inline_data(inode, page, iomap);



		if (ret)

			return ret;

		return PAGE_SIZE;

	}

	if (iomap->type == IOMAP_INLINE)

		return iomap_read_inline_data(inode, page, iomap);



	/* zero post-eof blocks as the page may be mapped */

	iop = iomap_page_create(inode, page);
@@ -593,10 +586,15 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, 
static int iomap_write_begin_inline(struct inode *inode,

		struct page *page, struct iomap *srcmap)

{

	int ret;



	/* needs more work for the tailpacking case; disable for now */

	if (WARN_ON_ONCE(srcmap->offset != 0))

		return -EIO;

	return iomap_read_inline_data(inode, page, srcmap);

	ret = iomap_read_inline_data(inode, page, srcmap);

	if (ret < 0)

		return ret;

	return 0;

}



static int