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authorDarrick J. Wong <djwong@us.ibm.com>2012-04-29 18:45:10 -0400
committerTheodore Ts'o <tytso@mit.edu>2012-04-29 18:45:10 -0400
commitfeb0ab32a57e4e6c8b24f6fb68f0ce08efe4603c (patch)
tree6438fc46013c2f5d60e78060c66e2809c6056f1a /fs/ext4
parentcc8e94fd126ab2d2e4bcb1b65c7316196f0cec8c (diff)
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>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/balloc.c4
-rw-r--r--fs/ext4/ext4.h6
-rw-r--r--fs/ext4/ialloc.c17
-rw-r--r--fs/ext4/inode.c3
-rw-r--r--fs/ext4/mballoc.c6
-rw-r--r--fs/ext4/resize.c9
-rw-r--r--fs/ext4/super.c81
7 files changed, 76 insertions, 50 deletions
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 0a64e4d5dba..5745d53c67e 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -168,7 +168,7 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
/* If checksum is bad mark all blocks used 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);
@@ -214,7 +214,7 @@ 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(sb, 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 57d7c356eaa..84e76bb9607 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2114,10 +2114,10 @@ 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,
+extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
struct ext4_group_desc *gdp);
+extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
+ struct ext4_group_desc *gdp);
static inline int ext4_has_group_desc_csum(struct super_block *sb)
{
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index a6383fcb714..a044a9b7749 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,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 16a67359b4c..7bccdf32a32 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3584,8 +3584,7 @@ make_io:
b = table;
end = b + EXT4_SB(sb)->s_inode_readahead_blks;
num = EXT4_INODES_PER_GROUP(sb);
- if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
- EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+ if (ext4_has_group_desc_csum(sb))
num -= ext4_itable_unused_count(sb, gdp);
table += num / inodes_per_block;
if (end > table)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 95a388fef39..ccb9c2f527d 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2799,7 +2799,7 @@ 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(sb, 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);
@@ -4663,7 +4663,7 @@ 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(sb, block_group, gdp);
ext4_unlock_group(sb, block_group);
percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters);
@@ -4809,7 +4809,7 @@ 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(sb, 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 dc597e06630..a58ce7c507a 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1160,7 +1160,7 @@ static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
EXT4_B2C(sbi, group_data->free_blocks_count));
ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
gdp->bg_flags = cpu_to_le16(*bg_flags);
- gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
+ ext4_group_desc_csum_set(sb, group, gdp);
err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
if (unlikely(err)) {
@@ -1399,17 +1399,14 @@ static int ext4_setup_next_flex_gd(struct super_block *sb,
(1 + ext4_bg_num_gdb(sb, group + i) +
le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
group_data[i].free_blocks_count = blocks_per_group - overhead;
- if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
- EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+ if (ext4_has_group_desc_csum(sb))
flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
EXT4_BG_INODE_UNINIT;
else
flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
}
- if (last_group == n_group &&
- EXT4_HAS_RO_COMPAT_FEATURE(sb,
- EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+ if (last_group == n_group && ext4_has_group_desc_csum(sb))
/* We need to initialize block bitmap of last group. */
flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f80c7e61282..c18c5968cd9 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1952,43 +1952,69 @@ 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))) {
+ /* 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);
}
-int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
+int ext4_group_desc_csum_verify(struct super_block *sb, __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)) &&
- (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
+ if (ext4_has_group_desc_csum(sb) &&
+ (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
+ block_group, gdp)))
return 0;
return 1;
}
+void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
+ struct ext4_group_desc *gdp)
+{
+ if (!ext4_has_group_desc_csum(sb))
+ return;
+ gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), 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)
@@ -2043,7 +2069,7 @@ static int ext4_check_descriptors(struct super_block *sb,
return 0;
}
ext4_lock_group(sb, i);
- if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
+ if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
"Checksum for group %u failed (%u!=%u)",
i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
@@ -3069,6 +3095,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
goto cantfind_ext4;
sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
+ /* Warn if metadata_csum and gdt_csum are both set. */
+ if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
+ EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+ ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
+ "redundant flags; please run fsck.");
+
/* Check for a known checksum algorithm */
if (!ext4_verify_csum_type(sb, es)) {
ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
@@ -4400,7 +4433,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
struct ext4_group_desc *gdp =
ext4_get_group_desc(sb, g, NULL);
- if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
+ if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
ext4_msg(sb, KERN_ERR,
"ext4_remount: Checksum for group %u failed (%u!=%u)",
g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),