[RFC 7/13] extents and 48bit ext3: Core 64 bit JBD changes

From: Mingming Cao
Date: Thu Jun 08 2006 - 21:22:12 EST

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Here is the patch to JBD to handle 64 bit block numbers, originally
from Zach Brown. This patch is useful only after adding support for
64-bit block numbers in the filesystem.

Signed-off-by: Badari Pulavarty <pbadari@xxxxxxxxxx>
Signed-off-by: Zach Brown <zach.brown@xxxxxxxxxx>

---

linux-2.6.16-ming/fs/jbd/commit.c | 16 +++++++++---
linux-2.6.16-ming/fs/jbd/journal.c | 11 ++++++++
linux-2.6.16-ming/fs/jbd/recovery.c | 42 +++++++++++++++++++++++-----------
linux-2.6.16-ming/fs/jbd/revoke.c | 14 ++++++++---
linux-2.6.16-ming/include/linux/jbd.h | 11 +++++++-
5 files changed, 72 insertions(+), 22 deletions(-)

diff -puN fs/jbd/commit.c~64bit_jbd_core fs/jbd/commit.c
--- linux-2.6.16/fs/jbd/commit.c~64bit_jbd_core 2006-06-08 16:29:51.822437025 -0700
+++ linux-2.6.16-ming/fs/jbd/commit.c 2006-06-08 16:49:51.639617345 -0700
@@ -160,6 +160,12 @@ static int journal_write_commit_record(j
return (ret == -EIO);
}

+static inline void write_split_be64(__be32 *high, __be32 *low, u64 val)
+{
+ *low = cpu_to_be32(val & (u32)~0);
+ *high = cpu_to_be32(val >> 32);
+}
+
/*
* journal_commit_transaction
*
@@ -182,6 +188,7 @@ void journal_commit_transaction(journal_
int first_tag = 0;
int tag_flag;
int i;
+ int tag_bytes = journal_tag_bytes(journal);

/*
* First job: lock down the current transaction and wait for
@@ -553,10 +560,11 @@ write_out_data:
tag_flag |= JFS_FLAG_SAME_UUID;

tag = (journal_block_tag_t *) tagp;
- tag->t_blocknr = cpu_to_be32(jh2bh(jh)->b_blocknr);
+ write_split_be64(&tag->t_blocknr_high, &tag->t_blocknr,
+ jh2bh(jh)->b_blocknr);
tag->t_flags = cpu_to_be32(tag_flag);
- tagp += sizeof(journal_block_tag_t);
- space_left -= sizeof(journal_block_tag_t);
+ tagp += tag_bytes;
+ space_left -= tag_bytes;

if (first_tag) {
memcpy (tagp, journal->j_uuid, 16);
@@ -570,7 +578,7 @@ write_out_data:

if (bufs == journal->j_wbufsize ||
commit_transaction->t_buffers == NULL ||
- space_left < sizeof(journal_block_tag_t) + 16) {
+ space_left < tag_bytes + 16) {

jbd_debug(4, "JBD: Submit %d IOs\n", bufs);

diff -puN fs/jbd/journal.c~64bit_jbd_core fs/jbd/journal.c
--- linux-2.6.16/fs/jbd/journal.c~64bit_jbd_core 2006-06-08 16:29:51.826436569 -0700
+++ linux-2.6.16-ming/fs/jbd/journal.c 2006-06-08 16:49:51.648616321 -0700
@@ -1602,6 +1602,17 @@ int journal_blocks_per_page(struct inode
}

/*
+ * helper functions to deal with 32 or 64bit block numbers.
+ */
+size_t journal_tag_bytes(journal_t *journal)
+{
+ if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT))
+ return sizeof(journal_block_tag_t);
+ else
+ return offsetof(journal_block_tag_t, t_blocknr_high);
+}
+
+/*
* Simple support for retrying memory allocations. Introduced to help to
* debug different VM deadlock avoidance strategies.
*/
diff -puN fs/jbd/recovery.c~64bit_jbd_core fs/jbd/recovery.c
--- linux-2.6.16/fs/jbd/recovery.c~64bit_jbd_core 2006-06-08 16:29:51.829436227 -0700
+++ linux-2.6.16-ming/fs/jbd/recovery.c 2006-06-08 16:49:51.640617231 -0700
@@ -178,19 +178,20 @@ static int jread(struct buffer_head **bh
* Count the number of in-use tags in a journal descriptor block.
*/

-static int count_tags(struct buffer_head *bh, int size)
+static int count_tags(journal_t *journal, struct buffer_head *bh)
{
char * tagp;
journal_block_tag_t * tag;
- int nr = 0;
+ int nr = 0, size = journal->j_blocksize;
+ int tag_bytes = journal_tag_bytes(journal);

tagp = &bh->b_data[sizeof(journal_header_t)];

- while ((tagp - bh->b_data + sizeof(journal_block_tag_t)) <= size) {
+ while ((tagp - bh->b_data + tag_bytes) <= size) {
tag = (journal_block_tag_t *) tagp;

nr++;
- tagp += sizeof(journal_block_tag_t);
+ tagp += tag_bytes;
if (!(tag->t_flags & cpu_to_be32(JFS_FLAG_SAME_UUID)))
tagp += 16;

@@ -307,6 +308,13 @@ int journal_skip_recovery(journal_t *jou
return err;
}

+static inline u64 read_split_be64(__be32 *high, __be32 *low)
+{
+ u64 ret = be32_to_cpu(*low);
+ ret |= (u64)be32_to_cpu(*high) << 32;
+ return ret;
+}
+
static int do_one_pass(journal_t *journal,
struct recovery_info *info, enum passtype pass)
{
@@ -318,11 +326,12 @@ static int do_one_pass(journal_t *journa
struct buffer_head * bh;
unsigned int sequence;
int blocktype;
+ int tag_bytes = journal_tag_bytes(journal);

/* Precompute the maximum metadata descriptors in a descriptor block */
int MAX_BLOCKS_PER_DESC;
MAX_BLOCKS_PER_DESC = ((journal->j_blocksize-sizeof(journal_header_t))
- / sizeof(journal_block_tag_t));
+ / tag_bytes);

/*
* First thing is to establish what we expect to find in the log
@@ -412,8 +421,7 @@ static int do_one_pass(journal_t *journa
* in pass REPLAY; otherwise, just skip over the
* blocks it describes. */
if (pass != PASS_REPLAY) {
- next_log_block +=
- count_tags(bh, journal->j_blocksize);
+ next_log_block += count_tags(journal, bh);
wrap(journal, next_log_block);
brelse(bh);
continue;
@@ -424,7 +432,7 @@ static int do_one_pass(journal_t *journa
* getting done here! */

tagp = &bh->b_data[sizeof(journal_header_t)];
- while ((tagp - bh->b_data +sizeof(journal_block_tag_t))
+ while ((tagp - bh->b_data + tag_bytes)
<= journal->j_blocksize) {
unsigned long io_block;

@@ -446,7 +454,8 @@ static int do_one_pass(journal_t *journa
unsigned long blocknr;

J_ASSERT(obh != NULL);
- blocknr = be32_to_cpu(tag->t_blocknr);
+ blocknr = read_split_be64(&tag->t_blocknr_high,
+ &tag->t_blocknr);

/* If the block has been
* revoked, then we're all done
@@ -494,7 +503,7 @@ static int do_one_pass(journal_t *journa
}

skip_write:
- tagp += sizeof(journal_block_tag_t);
+ tagp += tag_bytes;
if (!(flags & JFS_FLAG_SAME_UUID))
tagp += 16;

@@ -571,17 +580,24 @@ static int scan_revoke_records(journal_t
{
journal_revoke_header_t *header;
int offset, max;
+ int record_len = 4;

header = (journal_revoke_header_t *) bh->b_data;
offset = sizeof(journal_revoke_header_t);
max = be32_to_cpu(header->r_count);

- while (offset < max) {
+ if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT))
+ record_len = 8;
+
+ while (offset + record_len < max) {
unsigned long blocknr;
int err;

- blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
- offset += 4;
+ if (record_len == 4)
+ blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
+ else
+ blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset)));
+ offset += record_len;
err = journal_set_revoke(journal, blocknr, sequence);
if (err)
return err;
diff -puN fs/jbd/revoke.c~64bit_jbd_core fs/jbd/revoke.c
--- linux-2.6.16/fs/jbd/revoke.c~64bit_jbd_core 2006-06-08 16:29:51.832435885 -0700
+++ linux-2.6.16-ming/fs/jbd/revoke.c 2006-06-08 16:49:51.642617003 -0700
@@ -584,9 +584,17 @@ static void write_one_revoke_record(jour
*descriptorp = descriptor;
}

- * ((__be32 *)(&jh2bh(descriptor)->b_data[offset])) =
- cpu_to_be32(record->blocknr);
- offset += 4;
+ if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT)) {
+ * ((__be64 *)(&jh2bh(descriptor)->b_data[offset])) =
+ cpu_to_be64(record->blocknr);
+ offset += 8;
+
+ } else {
+ * ((__be32 *)(&jh2bh(descriptor)->b_data[offset])) =
+ cpu_to_be32(record->blocknr);
+ offset += 4;
+ }
+
*offsetp = offset;
}

diff -puN include/linux/jbd.h~64bit_jbd_core include/linux/jbd.h
--- linux-2.6.16/include/linux/jbd.h~64bit_jbd_core 2006-06-08 16:29:51.835435543 -0700
+++ linux-2.6.16-ming/include/linux/jbd.h 2006-06-08 16:49:51.645616662 -0700
@@ -147,12 +147,16 @@ typedef struct journal_header_s

/*
- * The block tag: used to describe a single buffer in the journal
+ * The block tag: used to describe a single buffer in the journal.
+ * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this
+ * raw struct shouldn't be used for pointer math or sizeof() - use
+ * journal_tag_bytes(journal) instead to compute this.
*/
typedef struct journal_block_tag_s
{
__be32 t_blocknr; /* The on-disk block number */
__be32 t_flags; /* See below */
+ __be32 t_blocknr_high; /* most-significant high 32bits. */
} journal_block_tag_t;

/*
@@ -232,11 +236,13 @@ typedef struct journal_superblock_s
((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))

#define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
+#define JFS_FEATURE_INCOMPAT_64BIT 0x00000002

/* Features known to this kernel version: */
#define JFS_KNOWN_COMPAT_FEATURES 0
#define JFS_KNOWN_ROCOMPAT_FEATURES 0
-#define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
+#define JFS_KNOWN_INCOMPAT_FEATURES (JFS_FEATURE_INCOMPAT_REVOKE | \
+ JFS_FEATURE_INCOMPAT_64BIT)

#ifdef __KERNEL__

@@ -1044,6 +1050,7 @@ static inline int tid_geq(tid_t x, tid_t
}

extern int journal_blocks_per_page(struct inode *inode);
+extern size_t journal_tag_bytes(journal_t *journal);

/*
* Return the minimum number of blocks which must be free in the journal

_

-
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Next message: Mingming Cao: "[RFC 8/13] extents and 48bit ext3: JBD layer in-kernel blockvariables type fixes"
Previous message: Mingming Cao: "[RFC 5/13] extents and 48bit ext3: sector_t type format string"
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