btrfs: simplify support block size check

Currently we manually check the block size against 3 different values:

- 4K
- PAGE_SIZE
- MIN_BLOCKSIZE

Those 3 values can match or differ from each other.  This makes it
pretty complex to output the supported block sizes.

Considering we're going to add block size > page size support soon, this
can make the support block size sysfs attribute much harder to
implement.

To make it easier, factor out a helper, btrfs_supported_blocksize() to
do a simple check for the block size.

Then utilize it in the two locations:

- btrfs_validate_super()
  This is very straightforward

- supported_sectorsizes_show()
  Iterate through all valid block sizes, and only output supported ones.

  This is to make future full range block sizes support much easier.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 1 insertions, 15 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 70fc4e7cc5a0..123c397ca8f8 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2438,21 +2438,7 @@ int btrfs_validate_super(const struct btrfs_fs_info *fs_info,
 		ret = -EINVAL;
 	}
 
-	/*
-	 * We only support at most 3 sectorsizes: 4K, PAGE_SIZE, MIN_BLOCKSIZE.
-	 *
-	 * For 4K page sized systems with non-debug builds, all 3 matches (4K).
-	 * For 4K page sized systems with debug builds, there are two block sizes
-	 * supported. (4K and 2K)
-	 *
-	 * 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 (sectorsize > PAGE_SIZE || (sectorsize != SZ_4K &&
-				       sectorsize != PAGE_SIZE &&
-				       sectorsize != BTRFS_MIN_BLOCKSIZE)) {
+	if (!btrfs_supported_blocksize(sectorsize)) {
 		btrfs_err(fs_info,
 			"sectorsize %llu not yet supported for page size %lu",
 			sectorsize, PAGE_SIZE);