[PATCH V15 07/15] Btrfs: subpage-blocksize: Allow mounting filesystems where sectorsize != PAGE_SIZE

[Chandan Rajendra <chandan@linux.vnet.ibm.com>]

This patch allows mounting filesystems with blocksize smaller than the
PAGE_SIZE.

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
---
 fs/btrfs/disk-io.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ea540ba..07ccae3 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -4095,17 +4095,12 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
 	 * Check sectorsize and nodesize first, other check will need it.
 	 * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
 	 */
-	if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
+	if (!is_power_of_2(sectorsize) || sectorsize < 2048 ||
 	    sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
 		printk(KERN_ERR "BTRFS: invalid sectorsize %llu\n", sectorsize);
 		ret = -EINVAL;
 	}
-	/* Only PAGE SIZE is supported yet */
-	if (sectorsize != PAGE_CACHE_SIZE) {
-		printk(KERN_ERR "BTRFS: sectorsize %llu not supported yet, only support %lu\n",
-				sectorsize, PAGE_CACHE_SIZE);
-		ret = -EINVAL;
-	}
+
 	if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
 	    nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
 		printk(KERN_ERR "BTRFS: invalid nodesize %llu\n", nodesize);
@@ -4129,6 +4124,7 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
 				btrfs_super_chunk_root(sb));
 		ret = -EINVAL;
 	}
+
 	if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
 		printk(KERN_WARNING "BTRFS: log_root block unaligned: %llu\n",
 				btrfs_super_log_root(sb));
-- 
2.1.0