lkml.org 
[lkml]   [2011]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH 13/23] ext4: Add new feature to make block group checksums use metadata_csum algorithm
From
Date
Add a new feature flag to enable block group descriptors to use the (faster)
metadata_csum checksum algorithm.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
fs/ext4/balloc.c | 2 +-
fs/ext4/ext4.h | 4 ++-
fs/ext4/ialloc.c | 11 ++++-----
fs/ext4/mballoc.c | 6 ++---
fs/ext4/resize.c | 2 +-
fs/ext4/super.c | 65 ++++++++++++++++++++++++++++++++++++++---------------
6 files changed, 59 insertions(+), 31 deletions(-)

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index dcac4bd..300f751 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -212,7 +212,7 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
sb->s_blocksize * 8, bh->b_data);
ext4_block_bitmap_csum_set(sb, block_group, gdp, bh,
EXT4_BLOCKS_PER_GROUP(sb) / 8);
- gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
+ ext4_group_desc_csum_set(sbi, block_group, gdp);
}

/* Return the number of free blocks in a block group. It is used when
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index e7489c4..ae71af3 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2086,10 +2086,10 @@ 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, __u32 count);
-extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
- struct ext4_group_desc *gdp);
extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
struct ext4_group_desc *gdp);
+extern void ext4_group_desc_csum_set(struct ext4_sb_info *sbi, __u32 group,
+ struct ext4_group_desc *gdp);

static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
{
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 261ffce..6d33995 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -92,7 +92,7 @@ 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(sbi, block_group, gdp);

return EXT4_INODES_PER_GROUP(sb);
}
@@ -287,7 +287,7 @@ 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(sbi, block_group, gdp);
ext4_unlock_group(sb, block_group);

percpu_counter_inc(&sbi->s_freeinodes_counter);
@@ -697,7 +697,7 @@ static int ext4_claim_inode(struct super_block *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(sbi, group, gdp);
err_ret:
ext4_unlock_group(sb, group);
up_read(&grp->alloc_sem);
@@ -858,8 +858,7 @@ 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(sbi, group, gdp);
}
ext4_unlock_group(sb, group);

@@ -1223,7 +1222,7 @@ 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(sbi, group, gdp);
ext4_unlock_group(sb, group);

BUFFER_TRACE(group_desc_bh,
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index dbd1453..2bbd9ee 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2919,7 +2919,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
ext4_free_group_clusters_set(sb, gdp, len);
ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh,
EXT4_BLOCKS_PER_GROUP(sb) / 8);
- gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
+ ext4_group_desc_csum_set(sbi, ac->ac_b_ex.fe_group, gdp);

ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len);
@@ -4787,7 +4787,7 @@ do_more:
ext4_free_group_clusters_set(sb, gdp, ret);
ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
EXT4_BLOCKS_PER_GROUP(sb) / 8);
- gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
+ ext4_group_desc_csum_set(sbi, block_group, gdp);
ext4_unlock_group(sb, block_group);
percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters);

@@ -4933,7 +4933,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
ext4_free_group_clusters_set(sb, desc, blk_free_count);
ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh,
EXT4_BLOCKS_PER_GROUP(sb) / 8);
- desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc);
+ ext4_group_desc_csum_set(sbi, block_group, desc);
ext4_unlock_group(sb, block_group);
percpu_counter_add(&sbi->s_freeclusters_counter,
EXT4_B2C(sbi, blocks_freed));
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index c33b72a..083f429 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -880,7 +880,7 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
ext4_free_group_clusters_set(sb, gdp, input->free_blocks_count);
ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
gdp->bg_flags = cpu_to_le16(EXT4_BG_INODE_ZEROED);
- gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp);
+ ext4_group_desc_csum_set(sbi, input->group, gdp);

/*
* We can allocate memory for mb_alloc based on the new group
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 5e2842c..6838d01 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2092,29 +2092,49 @@ failed:
return 0;
}

-__le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
- struct ext4_group_desc *gdp)
+static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
+ struct ext4_group_desc *gdp)
{
+ int offset;
__u16 crc = 0;
+ __le32 le_group = cpu_to_le32(block_group);

- if (sbi->s_es->s_feature_ro_compat &
- cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
- int offset = offsetof(struct ext4_group_desc, bg_checksum);
- __le32 le_group = cpu_to_le32(block_group);
-
- crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
- crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
- crc = crc16(crc, (__u8 *)gdp, offset);
- offset += sizeof(gdp->bg_checksum); /* skip checksum */
- /* for checksum of struct ext4_group_desc do the rest...*/
- if ((sbi->s_es->s_feature_incompat &
- cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
- offset < le16_to_cpu(sbi->s_es->s_desc_size))
- crc = crc16(crc, (__u8 *)gdp + offset,
- le16_to_cpu(sbi->s_es->s_desc_size) -
- offset);
+ if ((sbi->s_es->s_feature_ro_compat &
+ cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) &&
+ (sbi->s_es->s_feature_incompat &
+ cpu_to_le32(EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM))) {
+ /* Use new metadata_csum algorithm */
+ __u16 old_csum;
+ __u32 csum32;
+
+ old_csum = gdp->bg_checksum;
+ gdp->bg_checksum = 0;
+ csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
+ sizeof(le_group));
+ csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
+ sbi->s_desc_size);
+ gdp->bg_checksum = old_csum;
+
+ crc = csum32 & 0xFFFF;
+ goto out;
}

+ /* old crc16 code */
+ offset = offsetof(struct ext4_group_desc, bg_checksum);
+
+ crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
+ crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
+ crc = crc16(crc, (__u8 *)gdp, offset);
+ offset += sizeof(gdp->bg_checksum); /* skip checksum */
+ /* for checksum of struct ext4_group_desc do the rest...*/
+ if ((sbi->s_es->s_feature_incompat &
+ cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
+ offset < le16_to_cpu(sbi->s_es->s_desc_size))
+ crc = crc16(crc, (__u8 *)gdp + offset,
+ le16_to_cpu(sbi->s_es->s_desc_size) -
+ offset);
+
+out:
return cpu_to_le16(crc);
}

@@ -2129,6 +2149,15 @@ int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
return 1;
}

+void ext4_group_desc_csum_set(struct ext4_sb_info *sbi, __u32 block_group,
+ struct ext4_group_desc *gdp)
+{
+ if (!(sbi->s_es->s_feature_ro_compat &
+ cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
+ return;
+ gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
+}
+
/* Called at mount-time, super-block is locked */
static int ext4_check_descriptors(struct super_block *sb,
ext4_group_t *first_not_zeroed)


\
 
 \ /
  Last update: 2011-12-14 01:51    [W:0.119 / U:0.556 seconds]
©2003-2014 Jasper Spaans. Advertise on this site