[RFC PATCH V11 07/21] Btrfs: subpagesize-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 | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9800888..5dea6b4 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2816,12 +2816,6 @@ int open_ctree(struct super_block *sb,
 		goto fail_sb_buffer;
 	}
 
-	if (sectorsize != PAGE_SIZE) {
-		printk(KERN_ERR "BTRFS: incompatible sector size (%lu) "
-		       "found on %s\n", (unsigned long)sectorsize, sb->s_id);
-		goto fail_sb_buffer;
-	}
-
 	mutex_lock(&fs_info->chunk_mutex);
 	ret = btrfs_read_sys_array(tree_root);
 	mutex_unlock(&fs_info->chunk_mutex);
@@ -3963,13 +3957,13 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
 	 * Check the lower bound, the alignment and other constraints are
 	 * checked later.
 	 */
-	if (btrfs_super_nodesize(sb) < 4096) {
-		printk(KERN_ERR "BTRFS: nodesize too small: %u < 4096\n",
+	if (btrfs_super_nodesize(sb) < 2048) {
+		printk(KERN_ERR "BTRFS: nodesize too small: %u < 2048\n",
 				btrfs_super_nodesize(sb));
 		ret = -EINVAL;
 	}
-	if (btrfs_super_sectorsize(sb) < 4096) {
-		printk(KERN_ERR "BTRFS: sectorsize too small: %u < 4096\n",
+	if (btrfs_super_sectorsize(sb) < 2048) {
+		printk(KERN_ERR "BTRFS: sectorsize too small: %u < 2048\n",
 				btrfs_super_sectorsize(sb));
 		ret = -EINVAL;
 	}
-- 
2.1.0