Commit 1a42daab authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: expand subpage support to any PAGE_SIZE > 4K 



With the recent change in metadata handling, we can handle metadata in
the following cases:

- nodesize < PAGE_SIZE and sectorsize < PAGE_SIZE
  Go subpage routine for both metadata and data.

- nodesize < PAGE_SIZE and sectorsize >= PAGE_SIZE
  Invalid case for now. As we require nodesize >= sectorsize.

- nodesize >= PAGE_SIZE and sectorsize < PAGE_SIZE
  Go subpage routine for data, but regular page routine for metadata.

- nodesize >= PAGE_SIZE and sectorsize >= PAGE_SIZE
  Go regular page routine for both metadata and data.

Now we can handle any sectorsize < PAGE_SIZE, plus the existing
sectorsize == PAGE_SIZE support.

But here we introduce an artificial limit, any PAGE_SIZE > 4K case, we
will only support 4K and PAGE_SIZE as sector size.

The idea here is to reduce the test combinations, and push 4K as the
default standard in the future.

Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent fbca46eb

fs/btrfs/disk-io.c

+7 −5
Original line number Diff line number Diff line
@@ -2835,12 +2835,14 @@ static int validate_super(struct btrfs_fs_info *fs_info, 
	}



	/*

	 * For 4K page size, we only support 4K sector size.

	 * For 64K page size, we support 64K and 4K sector sizes.

	 * We only support at most two sectorsizes: 4K and PAGE_SIZE.

	 *

	 * We can support 16K sectorsize with 64K page size without problem,

	 * but such sectorsize/pagesize combination doesn't make much sense.

	 * 4K will be our future standard, PAGE_SIZE is supported from the very

	 * beginning.

	 */

	if ((PAGE_SIZE == SZ_4K && sectorsize != PAGE_SIZE) ||

	    (PAGE_SIZE == SZ_64K && (sectorsize != SZ_4K &&

				     sectorsize != SZ_64K))) {

	if (sectorsize > PAGE_SIZE || (sectorsize != SZ_4K && sectorsize != PAGE_SIZE)) {

		btrfs_err(fs_info,

			"sectorsize %llu not yet supported for page size %lu",

			sectorsize, PAGE_SIZE);

fs/btrfs/sysfs.c

+2 −4
Original line number Diff line number Diff line
@@ -394,11 +394,9 @@ static ssize_t supported_sectorsizes_show(struct kobject *kobj, 
{

	ssize_t ret = 0;



	/* 4K sector size is also supported with 64K page size */

	if (PAGE_SIZE == SZ_64K)

	/* An artificial limit to only support 4K and PAGE_SIZE */

	if (PAGE_SIZE > SZ_4K)

		ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);



	/* Only sectorsize == PAGE_SIZE is now supported */

	ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);



	return ret;