ext4: make block group checksums use metadata_csum algorithm

metadata_csum supersedes uninit_bg.  Convert the ROCOMPAT uninit_bg
flag check to a helper function that covers both, and make the
checksum calculation algorithm use either crc16 or the metadata_csum
chosen algorithm depending on which flag is set.  Print a warning if
we try to mount a filesystem with both feature flags set.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 7 insertions, 10 deletions

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index a6383fcb714b..a044a9b77491 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -70,13 +70,11 @@ static unsigned ext4_init_inode_bitmap(struct super_block *sb,
                                        ext4_group_t block_group,
                                        struct ext4_group_desc *gdp)
 {
-        struct ext4_sb_info *sbi = EXT4_SB(sb);
-
         J_ASSERT_BH(bh, buffer_locked(bh));
 
         /* If checksum is bad mark all blocks and inodes use to prevent
          * allocation, essentially implementing a per-group read-only flag. */
-        if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
+        if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
                 ext4_error(sb, "Checksum bad for group %u", block_group);
                 ext4_free_group_clusters_set(sb, gdp, 0);
                 ext4_free_inodes_set(sb, gdp, 0);
@@ -92,7 +90,7 @@ static unsigned ext4_init_inode_bitmap(struct super_block *sb,
                         bh->b_data);
         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
                                    EXT4_INODES_PER_GROUP(sb) / 8);
-        gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
+        ext4_group_desc_csum_set(sb, block_group, gdp);
 
         return EXT4_INODES_PER_GROUP(sb);
 }
@@ -298,7 +296,7 @@ void ext4_free_inode(handle_t *handle, struct inode *inode)
         }
         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
                                    EXT4_INODES_PER_GROUP(sb) / 8);
-        gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
+        ext4_group_desc_csum_set(sb, block_group, gdp);
         ext4_unlock_group(sb, block_group);
 
         percpu_counter_inc(&sbi->s_freeinodes_counter);
@@ -731,7 +729,7 @@ repeat_in_this_group:
 
 got:
         /* We may have to initialize the block bitmap if it isn't already */
-        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
+        if (ext4_has_group_desc_csum(sb) &&
             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
                 struct buffer_head *block_bitmap_bh;
 
@@ -757,8 +755,7 @@ got:
                                                    block_bitmap_bh,
                                                    EXT4_BLOCKS_PER_GROUP(sb) /
                                                    8);
-                        gdp->bg_checksum = ext4_group_desc_csum(sbi, group,
-                                                                gdp);
+                        ext4_group_desc_csum_set(sb, group, gdp);
                 }
                 ext4_unlock_group(sb, group);
 
@@ -811,7 +808,7 @@ got:
         if (ext4_has_group_desc_csum(sb)) {
                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
                                            EXT4_INODES_PER_GROUP(sb) / 8);
-                gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
+                ext4_group_desc_csum_set(sb, group, gdp);
                 ext4_unlock_group(sb, group);
         }
 
@@ -1181,7 +1178,7 @@ int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
 skip_zeroout:
         ext4_lock_group(sb, group);
         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
-        gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
+        ext4_group_desc_csum_set(sb, group, gdp);
         ext4_unlock_group(sb, group);
 
         BUFFER_TRACE(group_desc_bh,