diff mbox

[-V2,4/5] ext4: Use both hi and lo bits of the group desc values.

Message ID 1227285875-18011-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com
State Superseded, archived
Headers show

Commit Message

Aneesh Kumar K.V Nov. 21, 2008, 4:44 p.m. UTC 
Rename the lower bits with suffix _lo and add helper
to access the values. Also rename bg_itable_unused_hi
to bg_pad as in e2fsprogs. bg_itable_unused_hi is never
used before

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 fs/ext4/balloc.c  |   13 ++++----
 fs/ext4/ext4.h    |   24 +++++++++++++--
 fs/ext4/ialloc.c  |   83 ++++++++++++++++++++++++++++-------------------------
 fs/ext4/inode.c   |    2 +-
 fs/ext4/mballoc.c |   15 +++++----
 fs/ext4/resize.c  |    4 +-
 fs/ext4/super.c   |   64 +++++++++++++++++++++++++++++++++++++++-
 7 files changed, 144 insertions(+), 61 deletions(-)

Comments

Eric Sandeen Nov. 21, 2008, 5:29 p.m. UTC | #1 
Aneesh Kumar K.V wrote:
> Rename the lower bits with suffix _lo and add helper
> to access the values. Also rename bg_itable_unused_hi
> to bg_pad as in e2fsprogs. bg_itable_unused_hi is never
> used before

Maybe you can add info about under which circumstances (what sort of
fielsystem geometry) the hi bits are needed?  And the failure mode when
we don't use them, if that's known?

Sorry, I'm being nitpicky about commitlogs today :)

-Eric
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Aneesh Kumar K.V Nov. 21, 2008, 5:41 p.m. UTC | #2 
On Fri, Nov 21, 2008 at 11:29:49AM -0600, Eric Sandeen wrote:
> Aneesh Kumar K.V wrote:
> > Rename the lower bits with suffix _lo and add helper
> > to access the values. Also rename bg_itable_unused_hi
> > to bg_pad as in e2fsprogs. bg_itable_unused_hi is never
> > used before
> 
> Maybe you can add info about under which circumstances (what sort of
> fielsystem geometry) the hi bits are needed?  And the failure mode when
> we don't use them, if that's known?

Coly actually said it was added for inode reservation. But he agreed to
drop the high bits now and add them later once the performance issue
with the patch is addressed.

-aneesh
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Eric Sandeen Nov. 21, 2008, 5:53 p.m. UTC | #3 
Aneesh Kumar K.V wrote:
> On Fri, Nov 21, 2008 at 11:29:49AM -0600, Eric Sandeen wrote:
>> Aneesh Kumar K.V wrote:
>>> Rename the lower bits with suffix _lo and add helper
>>> to access the values. Also rename bg_itable_unused_hi
>>> to bg_pad as in e2fsprogs. bg_itable_unused_hi is never
>>> used before
>> Maybe you can add info about under which circumstances (what sort of
>> fielsystem geometry) the hi bits are needed?  And the failure mode when
>> we don't use them, if that's known?
> 
> Coly actually said it was added for inode reservation. But he agreed to
> drop the high bits now and add them later once the performance issue
> with the patch is addressed.
> 
> -aneesh

Ok, and for the rest?  (free_blocks, free_inodes) - I guess these are
only needed for > 2^32 block filesystems?

Thanks,
-eric
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Andreas Dilger Nov. 23, 2008, 4:09 a.m. UTC | #4 
On Nov 21, 2008  11:53 -0600, Eric Sandeen wrote:
> Ok, and for the rest?  (free_blocks, free_inodes) - I guess these are
> only needed for > 2^32 block filesystems?

Actually, since this is a per-group number, I'm not sure why this is
needed at all.  I don't object to keeping the helper functions though.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.

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Theodore Ts'o Nov. 24, 2008, 1:21 a.m. UTC | #5 
On Sat, Nov 22, 2008 at 10:09:39PM -0600, Andreas Dilger wrote:
> On Nov 21, 2008  11:53 -0600, Eric Sandeen wrote:
> > Ok, and for the rest?  (free_blocks, free_inodes) - I guess these are
> > only needed for > 2^32 block filesystems?
> 
> Actually, since this is a per-group number, I'm not sure why this is
> needed at all.  I don't object to keeping the helper functions though.

For most systems, it wn't be needed at all.  However, for filesystems
with block sizes >= 8k, we run into a limit where the maximum number
of blocks and inodes we can support per block group is 65528 (we can't
support 65536 since that would cause bg_free_blocks_count and/or
bg_free_blocks_count, which are both __u16 types, to overflow).  So on
systems with a page size > 4k, or if Christoph's patch to support fs
block sizes > page size ever makes it into mainline, this support
could be useful.

						- Ted
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Theodore Ts'o Nov. 24, 2008, 2:13 a.m. UTC | #6 
On Fri, Nov 21, 2008 at 11:11:10PM +0530, Aneesh Kumar K.V wrote:
> On Fri, Nov 21, 2008 at 11:29:49AM -0600, Eric Sandeen wrote:
> > Aneesh Kumar K.V wrote:
> > > Rename the lower bits with suffix _lo and add helper
> > > to access the values. Also rename bg_itable_unused_hi
> > > to bg_pad as in e2fsprogs. bg_itable_unused_hi is never
> > > used before
> > 
> > Maybe you can add info about under which circumstances (what sort of
> > fielsystem geometry) the hi bits are needed?  And the failure mode when
> > we don't use them, if that's known?
> 
> Coly actually said it was added for inode reservation. But he agreed to
> drop the high bits now and add them later once the performance issue
> with the patch is addressed.

The bg_itable_unused field is used for the lazy initialization of
inodes.  If the units of this field was blocks was blocks, we wouldn't
need bg_itable_unused_hi for quite a larger set of blocks.

I don't think we should nuke bg_itable_unused_hi, especially given
that we have a patch to support the kernel initializing the inodes
(yet to be reviewed).  As near as I can tell at the time when the
fields were added to e2fsprogs, we hadn't yet assigned the pad field
to bg_itable_unused_hi, but it's clearly needed if we want to support
a larger number of blocks or inodes per block group.

Instead we should create the helper functions for bg_itable_unused,
and update e2fsprogs to also support these fields.  Adding e2fsprogs
for large block groups is lower priority than large block numbers,
though.

						- Ted
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diff mbox

Patch

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index d268f5f..f2de3da 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -102,9 +102,9 @@  unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
 		if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
 			ext4_error(sb, __func__,
 				  "Checksum bad for group %u\n", block_group);
-			gdp->bg_free_blocks_count = 0;
-			gdp->bg_free_inodes_count = 0;
-			gdp->bg_itable_unused = 0;
+			ext4_free_blks_set(sb, gdp, 0);
+			ext4_free_inodes_set(sb, gdp, 0);
+			ext4_itable_unused_set(sb, gdp, 0);
 			memset(bh->b_data, 0xff, sb->s_blocksize);
 			return 0;
 		}
@@ -372,7 +372,7 @@  void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
 	struct ext4_group_desc *desc;
 	struct ext4_super_block *es;
 	struct ext4_sb_info *sbi;
-	int err = 0, ret;
+	int err = 0, ret, blk_free_count;
 	ext4_grpblk_t blocks_freed;
 	struct ext4_group_info *grp;
 
@@ -444,7 +444,8 @@  void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
 		}
 	}
 	spin_lock(sb_bgl_lock(sbi, block_group));
-	le16_add_cpu(&desc->bg_free_blocks_count, blocks_freed);
+	blk_free_count = blocks_freed + ext4_free_blks_count(sb, desc);
+	ext4_free_blks_set(sb, desc, blk_free_count);
 	desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc);
 	spin_unlock(sb_bgl_lock(sbi, block_group));
 	percpu_counter_add(&sbi->s_freeblocks_counter, blocks_freed);
@@ -742,7 +743,7 @@  ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
 		gdp = ext4_get_group_desc(sb, i, NULL);
 		if (!gdp)
 			continue;
-		desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
+		desc_count += ext4_free_blks_count(sb, gdp);
 	}
 
 	return desc_count;
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index ca88bd1..c1b2e41 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -161,9 +161,9 @@  struct ext4_group_desc
 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
 	__le32	bg_inode_table_lo;	/* Inodes table block */
-	__le16	bg_free_blocks_count;	/* Free blocks count */
-	__le16	bg_free_inodes_count;	/* Free inodes count */
-	__le16	bg_used_dirs_count;	/* Directories count */
+	__le16	bg_free_blocks_count_lo;/* Free blocks count */
+	__le16	bg_free_inodes_count_lo;/* Free inodes count */
+	__le16	bg_used_dirs_count_lo;	/* Directories count */
 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
 	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
 	__le16  bg_itable_unused;	/* Unused inodes count */
@@ -174,7 +174,7 @@  struct ext4_group_desc
 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
-	__le16	bg_itable_unused_hi;	/* Unused inodes count MSB */
+	__le16  bg_pad;
 	__u32	bg_reserved2[3];
 };
 
@@ -1200,12 +1200,28 @@  extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 				      struct ext4_group_desc *bg);
 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 				     struct ext4_group_desc *bg);
+extern __u32 ext4_free_blks_count(struct super_block *sb,
+				struct ext4_group_desc *bg);
+extern __u32 ext4_free_inodes_count(struct super_block *sb,
+				 struct ext4_group_desc *bg);
+extern __u32 ext4_used_dirs_count(struct super_block *sb,
+				struct ext4_group_desc *bg);
+extern __u16 ext4_itable_unused_count(struct super_block *sb,
+				   struct ext4_group_desc *bg);
 extern void ext4_block_bitmap_set(struct super_block *sb,
 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
 extern void ext4_inode_bitmap_set(struct super_block *sb,
 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
 extern void ext4_inode_table_set(struct super_block *sb,
 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
+extern void ext4_free_blks_set(struct super_block *sb,
+			       struct ext4_group_desc *bg, __u32 count);
+extern void ext4_free_inodes_set(struct super_block *sb,
+				struct ext4_group_desc *bg, __u32 count);
+extern void ext4_used_dirs_set(struct super_block *sb,
+				struct ext4_group_desc *bg, __u32 count);
+extern void ext4_itable_unused_set(struct super_block *sb,
+				   struct ext4_group_desc *bg, __u16 count);
 /* extents.c */
 extern int ext4_ext_journal_restart(handle_t *handle, int needed);
 /* defrag.c */
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 4039af6..84f060b 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -76,9 +76,9 @@  unsigned ext4_init_inode_bitmap(struct super_block *sb, struct buffer_head *bh,
 	if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
 		ext4_error(sb, __func__, "Checksum bad for group %u\n",
 			   block_group);
-		gdp->bg_free_blocks_count = 0;
-		gdp->bg_free_inodes_count = 0;
-		gdp->bg_itable_unused = 0;
+		ext4_free_blks_set(sb, gdp, 0);
+		ext4_free_inodes_set(sb, gdp, 0);
+		ext4_itable_unused_set(sb, gdp, 0);
 		memset(bh->b_data, 0xff, sb->s_blocksize);
 		return 0;
 	}
@@ -168,7 +168,7 @@  void ext4_free_inode(handle_t *handle, struct inode *inode)
 	struct ext4_group_desc *gdp;
 	struct ext4_super_block *es;
 	struct ext4_sb_info *sbi;
-	int fatal = 0, err;
+	int fatal = 0, err, count;
 	ext4_group_t flex_group;
 
 	if (atomic_read(&inode->i_count) > 1) {
@@ -236,9 +236,12 @@  void ext4_free_inode(handle_t *handle, struct inode *inode)
 
 		if (gdp) {
 			spin_lock(sb_bgl_lock(sbi, block_group));
-			le16_add_cpu(&gdp->bg_free_inodes_count, 1);
-			if (is_directory)
-				le16_add_cpu(&gdp->bg_used_dirs_count, -1);
+			count = ext4_free_inodes_count(sb, gdp) + 1;
+			ext4_free_inodes_set(sb, gdp, count);
+			if (is_directory) {
+				count = ext4_used_dirs_count(sb, gdp) - 1;
+				ext4_used_dirs_set(sb, gdp, count);
+			}
 			gdp->bg_checksum = ext4_group_desc_csum(sbi,
 							block_group, gdp);
 			spin_unlock(sb_bgl_lock(sbi, block_group));
@@ -291,13 +294,13 @@  static int find_group_dir(struct super_block *sb, struct inode *parent,
 
 	for (group = 0; group < ngroups; group++) {
 		desc = ext4_get_group_desc(sb, group, NULL);
-		if (!desc || !desc->bg_free_inodes_count)
+		if (!desc || !ext4_free_inodes_count(sb, desc))
 			continue;
-		if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
+		if (ext4_free_inodes_count(sb, desc) < avefreei)
 			continue;
 		if (!best_desc ||
-		    (le16_to_cpu(desc->bg_free_blocks_count) >
-		     le16_to_cpu(best_desc->bg_free_blocks_count))) {
+		    (ext4_free_blks_count(sb, desc) >
+		     ext4_free_blks_count(sb, best_desc))) {
 			*best_group = group;
 			best_desc = desc;
 			ret = 0;
@@ -369,7 +372,7 @@  static int find_group_flex(struct super_block *sb, struct inode *parent,
 	for (i = best_flex * flex_size; i < ngroups &&
 		     i < (best_flex + 1) * flex_size; i++) {
 		desc = ext4_get_group_desc(sb, i, &bh);
-		if (le16_to_cpu(desc->bg_free_inodes_count)) {
+		if (ext4_free_inodes_count(sb, desc)) {
 			*best_group = i;
 			goto out;
 		}
@@ -443,17 +446,17 @@  static int find_group_orlov(struct super_block *sb, struct inode *parent,
 		for (i = 0; i < ngroups; i++) {
 			grp = (parent_group + i) % ngroups;
 			desc = ext4_get_group_desc(sb, grp, NULL);
-			if (!desc || !desc->bg_free_inodes_count)
+			if (!desc || !ext4_free_inodes_count(sb, desc))
 				continue;
-			if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
+			if (ext4_used_dirs_count(sb, desc) >= best_ndir)
 				continue;
-			if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
+			if (ext4_free_inodes_count(sb, desc) < avefreei)
 				continue;
-			if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
+			if (ext4_free_blks_count(sb, desc) < avefreeb)
 				continue;
 			*group = grp;
 			ret = 0;
-			best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
+			best_ndir = ext4_used_dirs_count(sb, desc);
 		}
 		if (ret == 0)
 			return ret;
@@ -479,13 +482,13 @@  static int find_group_orlov(struct super_block *sb, struct inode *parent,
 	for (i = 0; i < ngroups; i++) {
 		*group = (parent_group + i) % ngroups;
 		desc = ext4_get_group_desc(sb, *group, NULL);
-		if (!desc || !desc->bg_free_inodes_count)
+		if (!desc || !ext4_free_inodes_count(sb, desc))
 			continue;
-		if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
+		if (ext4_used_dirs_count(sb, desc) >= max_dirs)
 			continue;
-		if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
+		if (ext4_free_inodes_count(sb, desc) < min_inodes)
 			continue;
-		if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
+		if (ext4_free_blks_count(sb, desc) < min_blocks)
 			continue;
 		return 0;
 	}
@@ -494,8 +497,8 @@  static int find_group_orlov(struct super_block *sb, struct inode *parent,
 	for (i = 0; i < ngroups; i++) {
 		*group = (parent_group + i) % ngroups;
 		desc = ext4_get_group_desc(sb, *group, NULL);
-		if (desc && desc->bg_free_inodes_count &&
-			le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
+		if (desc && ext4_free_inodes_count(sb, desc) &&
+			ext4_free_inodes_count(sb, desc) >= avefreei)
 			return 0;
 	}
 
@@ -524,8 +527,8 @@  static int find_group_other(struct super_block *sb, struct inode *parent,
 	 */
 	*group = parent_group;
 	desc = ext4_get_group_desc(sb, *group, NULL);
-	if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
-			le16_to_cpu(desc->bg_free_blocks_count))
+	if (desc && ext4_free_inodes_count(sb, desc) &&
+			ext4_free_blks_count(sb, desc))
 		return 0;
 
 	/*
@@ -548,8 +551,8 @@  static int find_group_other(struct super_block *sb, struct inode *parent,
 		if (*group >= ngroups)
 			*group -= ngroups;
 		desc = ext4_get_group_desc(sb, *group, NULL);
-		if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
-				le16_to_cpu(desc->bg_free_blocks_count))
+		if (desc && ext4_free_inodes_count(sb, desc) &&
+				ext4_free_blks_count(sb, desc))
 			return 0;
 	}
 
@@ -562,7 +565,7 @@  static int find_group_other(struct super_block *sb, struct inode *parent,
 		if (++*group >= ngroups)
 			*group = 0;
 		desc = ext4_get_group_desc(sb, *group, NULL);
-		if (desc && le16_to_cpu(desc->bg_free_inodes_count))
+		if (desc && ext4_free_inodes_count(sb, desc))
 			return 0;
 	}
 
@@ -591,7 +594,7 @@  struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
 	struct ext4_super_block *es;
 	struct ext4_inode_info *ei;
 	struct ext4_sb_info *sbi;
-	int ret2, err = 0;
+	int ret2, err = 0, count;
 	struct inode *ret;
 	ext4_group_t i;
 	int free = 0;
@@ -717,7 +720,7 @@  struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
 		if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 			gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
 			free = ext4_free_blocks_after_init(sb, group, gdp);
-			gdp->bg_free_blocks_count = cpu_to_le16(free);
+			ext4_free_blks_set(sb, gdp, free);
 			gdp->bg_checksum = ext4_group_desc_csum(sbi, group,
 								gdp);
 		}
@@ -751,7 +754,7 @@  struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
 			free = 0;
 		} else {
 			free = EXT4_INODES_PER_GROUP(sb) -
-				le16_to_cpu(gdp->bg_itable_unused);
+				ext4_itable_unused_count(sb, gdp);
 		}
 
 		/*
@@ -761,13 +764,15 @@  struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
 		 *
 		 */
 		if (ino > free)
-			gdp->bg_itable_unused =
-				cpu_to_le16(EXT4_INODES_PER_GROUP(sb) - ino);
+			ext4_itable_unused_set(sb, gdp,
+					(EXT4_INODES_PER_GROUP(sb) - ino));
 	}
 
-	le16_add_cpu(&gdp->bg_free_inodes_count, -1);
+	count = ext4_free_inodes_count(sb, gdp) - 1;
+	ext4_free_inodes_set(sb, gdp, count);
 	if (S_ISDIR(mode)) {
-		le16_add_cpu(&gdp->bg_used_dirs_count, 1);
+		count = ext4_used_dirs_count(sb, gdp) + 1;
+		ext4_used_dirs_set(sb, gdp, count);
 	}
 	gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
 	spin_unlock(sb_bgl_lock(sbi, group));
@@ -981,7 +986,7 @@  unsigned long ext4_count_free_inodes(struct super_block *sb)
 		gdp = ext4_get_group_desc(sb, i, NULL);
 		if (!gdp)
 			continue;
-		desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
+		desc_count += ext4_free_inodes_count(sb, gdp);
 		brelse(bitmap_bh);
 		bitmap_bh = ext4_read_inode_bitmap(sb, i);
 		if (!bitmap_bh)
@@ -989,7 +994,7 @@  unsigned long ext4_count_free_inodes(struct super_block *sb)
 
 		x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8);
 		printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
-			i, le16_to_cpu(gdp->bg_free_inodes_count), x);
+			i, ext4_free_inodes_count(sb, gdp), x);
 		bitmap_count += x;
 	}
 	brelse(bitmap_bh);
@@ -1003,7 +1008,7 @@  unsigned long ext4_count_free_inodes(struct super_block *sb)
 		gdp = ext4_get_group_desc(sb, i, NULL);
 		if (!gdp)
 			continue;
-		desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
+		desc_count += ext4_free_inodes_count(sb, gdp);
 		cond_resched();
 	}
 	return desc_count;
@@ -1020,7 +1025,7 @@  unsigned long ext4_count_dirs(struct super_block * sb)
 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
 		if (!gdp)
 			continue;
-		count += le16_to_cpu(gdp->bg_used_dirs_count);
+		count += ext4_used_dirs_count(sb, gdp);
 	}
 	return count;
 }
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 76b1d3a..2d31597 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3987,7 +3987,7 @@  static int __ext4_get_inode_loc(struct inode *inode,
 			num = EXT4_INODES_PER_GROUP(sb);
 			if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
-				num -= le16_to_cpu(gdp->bg_itable_unused);
+				num -= ext4_itable_unused_count(sb, gdp);
 			table += num / inodes_per_block;
 			if (end > table)
 				end = table;
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 1ed949c..cbba8f4 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2483,7 +2483,7 @@  int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
 			ext4_free_blocks_after_init(sb, group, desc);
 	} else {
 		meta_group_info[i]->bb_free =
-			le16_to_cpu(desc->bg_free_blocks_count);
+			ext4_free_blks_count(sb, desc);
 	}
 
 	INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
@@ -3017,12 +3017,12 @@  ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 				ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len);
 	if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 		gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
-		gdp->bg_free_blocks_count =
-			cpu_to_le16(ext4_free_blocks_after_init(sb,
-						ac->ac_b_ex.fe_group,
-						gdp));
+		ext4_free_blks_set(sb, gdp,
+					ext4_free_blocks_after_init(sb,
+					ac->ac_b_ex.fe_group, gdp));
 	}
-	le16_add_cpu(&gdp->bg_free_blocks_count, -ac->ac_b_ex.fe_len);
+	len = ext4_free_blks_count(sb, gdp) - ac->ac_b_ex.fe_len;
+	ext4_free_blks_set(sb, gdp, len);
 	gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
 	spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
 	percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len);
@@ -4799,7 +4799,8 @@  void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
 	}
 
 	spin_lock(sb_bgl_lock(sbi, block_group));
-	le16_add_cpu(&gdp->bg_free_blocks_count, count);
+	ret = ext4_free_blks_count(sb, gdp) + count;
+	ext4_free_blks_set(sb, gdp, ret);
 	gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
 	spin_unlock(sb_bgl_lock(sbi, block_group));
 	percpu_counter_add(&sbi->s_freeblocks_counter, count);
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 939cf26..6e61613 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -862,8 +862,8 @@  int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
 	ext4_block_bitmap_set(sb, gdp, input->block_bitmap); /* LV FIXME */
 	ext4_inode_bitmap_set(sb, gdp, input->inode_bitmap); /* LV FIXME */
 	ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */
-	gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count);
-	gdp->bg_free_inodes_count = cpu_to_le16(EXT4_INODES_PER_GROUP(sb));
+	ext4_free_blks_set(sb, gdp, input->free_blocks_count);
+	ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
 	gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp);
 
 	/*
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 42597b7..046471f 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -93,6 +93,36 @@  ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 		(ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 }
 
+__u32 ext4_free_blks_count(struct super_block *sb,
+			      struct ext4_group_desc *bg)
+{
+	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
+		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
+		(__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
+}
+
+__u32 ext4_free_inodes_count(struct super_block *sb,
+			      struct ext4_group_desc *bg)
+{
+	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
+		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
+		(__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
+}
+
+__u32 ext4_used_dirs_count(struct super_block *sb,
+			      struct ext4_group_desc *bg)
+{
+	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
+		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
+		(__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
+}
+
+__u16 ext4_itable_unused_count(struct super_block *sb,
+			      struct ext4_group_desc *bg)
+{
+	return le16_to_cpu(bg->bg_itable_unused);
+}
+
 void ext4_block_bitmap_set(struct super_block *sb,
 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
 {
@@ -117,6 +147,36 @@  void ext4_inode_table_set(struct super_block *sb,
 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 }
 
+void ext4_free_blks_set(struct super_block *sb,
+			  struct ext4_group_desc *bg, __u32 count)
+{
+	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
+	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
+		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
+}
+
+void ext4_free_inodes_set(struct super_block *sb,
+			  struct ext4_group_desc *bg, __u32 count)
+{
+	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
+	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
+		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
+}
+
+void ext4_used_dirs_set(struct super_block *sb,
+			  struct ext4_group_desc *bg, __u32 count)
+{
+	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
+	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
+		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
+}
+
+void ext4_itable_unused_set(struct super_block *sb,
+			  struct ext4_group_desc *bg, __u16 count)
+{
+	bg->bg_itable_unused = cpu_to_le16((__u16)count);
+}
+
 /*
  * Wrappers for jbd2_journal_start/end.
  *
@@ -1516,9 +1576,9 @@  static int ext4_fill_flex_info(struct super_block *sb)
 
 		flex_group = ext4_flex_group(sbi, i);
 		sbi->s_flex_groups[flex_group].free_inodes +=
-			le16_to_cpu(gdp->bg_free_inodes_count);
+			ext4_free_inodes_count(sb, gdp);
 		sbi->s_flex_groups[flex_group].free_blocks +=
-			le16_to_cpu(gdp->bg_free_blocks_count);
+			ext4_free_blks_count(sb, gdp);
 	}
 
 	return 1;