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jbd2: enable journal clients to enable v2 checksumming
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Add in the necessary code so that journal clients can enable the new
journal checksumming features.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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Darrick J. Wong authored and Theodore Ts'o committed May 27, 2012
1 parent 8f888ef commit 25ed6e8
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Showing 2 changed files with 92 additions and 13 deletions.
55 changes: 42 additions & 13 deletions fs/ext4/super.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3013,6 +3013,44 @@ static void ext4_destroy_lazyinit_thread(void)
kthread_stop(ext4_lazyinit_task);
}

static int set_journal_csum_feature_set(struct super_block *sb)
{
int ret = 1;
int compat, incompat;
struct ext4_sb_info *sbi = EXT4_SB(sb);

if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
/* journal checksum v2 */
compat = 0;
incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
} else {
/* journal checksum v1 */
compat = JBD2_FEATURE_COMPAT_CHECKSUM;
incompat = 0;
}

if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
ret = jbd2_journal_set_features(sbi->s_journal,
compat, 0,
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
incompat);
} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
ret = jbd2_journal_set_features(sbi->s_journal,
compat, 0,
incompat);
jbd2_journal_clear_features(sbi->s_journal, 0, 0,
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
} else {
jbd2_journal_clear_features(sbi->s_journal,
JBD2_FEATURE_COMPAT_CHECKSUM, 0,
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
JBD2_FEATURE_INCOMPAT_CSUM_V2);
}

return ret;
}

static int ext4_fill_super(struct super_block *sb, void *data, int silent)
{
char *orig_data = kstrdup(data, GFP_KERNEL);
Expand Down Expand Up @@ -3610,19 +3648,10 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
goto failed_mount_wq;
}

if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
jbd2_journal_set_features(sbi->s_journal,
JBD2_FEATURE_COMPAT_CHECKSUM, 0,
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
jbd2_journal_set_features(sbi->s_journal,
JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
jbd2_journal_clear_features(sbi->s_journal, 0, 0,
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
} else {
jbd2_journal_clear_features(sbi->s_journal,
JBD2_FEATURE_COMPAT_CHECKSUM, 0,
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
if (!set_journal_csum_feature_set(sb)) {
ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
"feature set");
goto failed_mount_wq;
}

/* We have now updated the journal if required, so we can
Expand Down
50 changes: 50 additions & 0 deletions fs/jbd2/journal.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,15 @@ EXPORT_SYMBOL(jbd2_inode_cache);
static void __journal_abort_soft (journal_t *journal, int errno);
static int jbd2_journal_create_slab(size_t slab_size);

/* Checksumming functions */
int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb)
{
if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
return 1;

return sb->s_checksum_type == JBD2_CRC32C_CHKSUM;
}

/*
* Helper function used to manage commit timeouts
*/
Expand Down Expand Up @@ -1376,6 +1385,9 @@ static int journal_get_superblock(journal_t *journal)
}
}

if (buffer_verified(bh))
return 0;

sb = journal->j_superblock;

err = -EINVAL;
Expand Down Expand Up @@ -1413,6 +1425,21 @@ static int journal_get_superblock(journal_t *journal)
goto out;
}

if (JBD2_HAS_COMPAT_FEATURE(journal, JBD2_FEATURE_COMPAT_CHECKSUM) &&
JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
/* Can't have checksum v1 and v2 on at the same time! */
printk(KERN_ERR "JBD: Can't enable checksumming v1 and v2 "
"at the same time!\n");
goto out;
}

if (!jbd2_verify_csum_type(journal, sb)) {
printk(KERN_ERR "JBD: Unknown checksum type\n");
goto out;
}

set_buffer_verified(bh);

return 0;

out:
Expand Down Expand Up @@ -1653,6 +1680,10 @@ int jbd2_journal_check_available_features (journal_t *journal, unsigned long com
int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
unsigned long ro, unsigned long incompat)
{
#define INCOMPAT_FEATURE_ON(f) \
((incompat & (f)) && !(sb->s_feature_incompat & cpu_to_be32(f)))
#define COMPAT_FEATURE_ON(f) \
((compat & (f)) && !(sb->s_feature_compat & cpu_to_be32(f)))
journal_superblock_t *sb;

if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
Expand All @@ -1661,16 +1692,35 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
return 0;

/* Asking for checksumming v2 and v1? Only give them v2. */
if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2 &&
compat & JBD2_FEATURE_COMPAT_CHECKSUM)
compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM;

jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
compat, ro, incompat);

sb = journal->j_superblock;

/* If enabling v2 checksums, update superblock */
if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
sb->s_checksum_type = JBD2_CRC32C_CHKSUM;
sb->s_feature_compat &=
~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM);
}

/* If enabling v1 checksums, downgrade superblock */
if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM))
sb->s_feature_incompat &=
~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2);

sb->s_feature_compat |= cpu_to_be32(compat);
sb->s_feature_ro_compat |= cpu_to_be32(ro);
sb->s_feature_incompat |= cpu_to_be32(incompat);

return 1;
#undef COMPAT_FEATURE_ON
#undef INCOMPAT_FEATURE_ON
}

/*
Expand Down

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