[PATCH] xfs: deduplicate xlog_do_recovery

Discussion:

[PATCH] xfs: deduplicate xlog_do_recovery_pass()

Eric Sandeen

2014-08-21 03:18:52 UTC

In xlog_do_recovery_pass(), there are 2 distinct cases:
non-wrapped and wrapped log recovery.

If we find a wrapped log, we recover around the end
of the log, and then handle the rest of recovery
exactly as in the non-wrapped case - using exactly the same
(duplicated) code.

Rather than having the same code in both cases, we can
get the wrapped portion out of the way first if needed,
and then recover the non-wrapped portion of the log.

There should be no functional change here, just code
reorganization & deduplication.

The patch looks a bit bigger than it really is; the last
hunk is whitespace changes (un-indenting).

Tested with xfstests "check -g log" on a stock configuration.

Signed-off-by: Eric Sandeen <***@redhat.com>
---

xfs_log_recover.c | 81 ++++++++++++++++++------------------------------------
1 file changed, 27 insertions(+), 54 deletions(-)

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 1fd5787..08d3569 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -4132,41 +4132,13 @@ xlog_do_recovery_pass(
}

memset(rhash, 0, sizeof(rhash));
- if (tail_blk <= head_blk) {
- for (blk_no = tail_blk; blk_no < head_blk; ) {
- error = xlog_bread(log, blk_no, hblks, hbp, &offset);
- if (error)
- goto bread_err2;
-
- rhead = (xlog_rec_header_t *)offset;
- error = xlog_valid_rec_header(log, rhead, blk_no);
- if (error)
- goto bread_err2;
-
- /* blocks in data section */
- bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
- error = xlog_bread(log, blk_no + hblks, bblks, dbp,
- &offset);
- if (error)
- goto bread_err2;
-
- error = xlog_unpack_data(rhead, offset, log);
- if (error)
- goto bread_err2;
-
- error = xlog_recover_process_data(log,
- rhash, rhead, offset, pass);
- if (error)
- goto bread_err2;
- blk_no += bblks + hblks;
- }
- } else {
+ blk_no = tail_blk;
+ if (tail_blk > head_blk) {
/*
* Perform recovery around the end of the physical log.
* When the head is not on the same cycle number as the tail,
- * we can't do a sequential recovery as above.
+ * we can't do a sequential recovery.
*/
- blk_no = tail_blk;
while (blk_no < log->l_logBBsize) {
/*
* Check for header wrapping around physical end-of-log
@@ -4280,34 +4252,35 @@ xlog_do_recovery_pass(

ASSERT(blk_no >= log->l_logBBsize);
blk_no -= log->l_logBBsize;
+ }

- /* read first part of physical log */
- while (blk_no < head_blk) {
- error = xlog_bread(log, blk_no, hblks, hbp, &offset);
- if (error)
- goto bread_err2;
+ /* read first part of physical log */
+ while (blk_no < head_blk) {
+ error = xlog_bread(log, blk_no, hblks, hbp, &offset);
+ if (error)
+ goto bread_err2;

- rhead = (xlog_rec_header_t *)offset;
- error = xlog_valid_rec_header(log, rhead, blk_no);
- if (error)
- goto bread_err2;
+ rhead = (xlog_rec_header_t *)offset;
+ error = xlog_valid_rec_header(log, rhead, blk_no);
+ if (error)
+ goto bread_err2;

- bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
- error = xlog_bread(log, blk_no+hblks, bblks, dbp,
- &offset);
- if (error)
- goto bread_err2;
+ /* blocks in data section */
+ bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
+ error = xlog_bread(log, blk_no+hblks, bblks, dbp,
+ &offset);
+ if (error)
+ goto bread_err2;

- error = xlog_unpack_data(rhead, offset, log);
- if (error)
- goto bread_err2;
+ error = xlog_unpack_data(rhead, offset, log);
+ if (error)
+ goto bread_err2;

- error = xlog_recover_process_data(log, rhash,
- rhead, offset, pass);
- if (error)
- goto bread_err2;
- blk_no += bblks + hblks;
- }
+ error = xlog_recover_process_data(log, rhash,
+ rhead, offset, pass);
+ if (error)
+ goto bread_err2;
+ blk_no += bblks + hblks;
}

bread_err2:

Eric Sandeen

2014-08-21 04:36:40 UTC

Permalink

which didn't actually hit any log wraps. Does xfstests
really not cover wrapped log recovery? anyway, something like this
on a small log:

[***@bp-05 xfstests]# while true; do mount /dev/sdc5 /mnt/scratch; ltp/fsstress -n 500 -d /mnt/scratch; src/godown -f /mnt/scratch; umount /mnt/scratch; done

hit plenty of log wraps w/ no problem.

-Eric

Dave Chinner

2014-08-21 04:49:15 UTC

Permalink

Post by Eric Sandeen

which didn't actually hit any log wraps. Does xfstests
really not cover wrapped log recovery? anyway, something like this

xfs/016

Cheers,

Dave.

--
Dave Chinner
***@fromorbit.com

Eric Sandeen

2014-08-21 04:58:55 UTC

Permalink

Post by Dave Chinner

Post by Eric Sandeen

which didn't actually hit any log wraps. Does xfstests
really not cover wrapped log recovery? anyway, something like this

xfs/016

AFAICT that doesn't ever run recovery...

-Eric

Dave Chinner

2014-08-21 05:12:51 UTC

Permalink

Post by Eric Sandeen

Post by Dave Chinner

Post by Eric Sandeen

which didn't actually hit any log wraps. Does xfstests
really not cover wrapped log recovery? anyway, something like this

xfs/016

AFAICT that doesn't ever run recovery...

It does:

loop 20 times {

mount
<do stuff>
unmount

dump and process log
}

Cheers,

Dave.

--
Dave Chinner
***@fromorbit.com

Brian Foster

2014-08-21 12:36:06 UTC

Permalink

Post by Eric Sandeen
non-wrapped and wrapped log recovery.
If we find a wrapped log, we recover around the end
of the log, and then handle the rest of recovery
exactly as in the non-wrapped case - using exactly the same
(duplicated) code.
Rather than having the same code in both cases, we can
get the wrapped portion out of the way first if needed,
and then recover the non-wrapped portion of the log.
There should be no functional change here, just code
reorganization & deduplication.
The patch looks a bit bigger than it really is; the last
hunk is whitespace changes (un-indenting).
Tested with xfstests "check -g log" on a stock configuration.
---
xfs_log_recover.c | 81 ++++++++++++++++++------------------------------------
1 file changed, 27 insertions(+), 54 deletions(-)
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 1fd5787..08d3569 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -4132,41 +4132,13 @@ xlog_do_recovery_pass(
}
memset(rhash, 0, sizeof(rhash));
- if (tail_blk <= head_blk) {
- for (blk_no = tail_blk; blk_no < head_blk; ) {
- error = xlog_bread(log, blk_no, hblks, hbp, &offset);
- if (error)
- goto bread_err2;
-
- rhead = (xlog_rec_header_t *)offset;
- error = xlog_valid_rec_header(log, rhead, blk_no);
- if (error)
- goto bread_err2;
-
- /* blocks in data section */
- bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
- error = xlog_bread(log, blk_no + hblks, bblks, dbp,
- &offset);
- if (error)
- goto bread_err2;
-
- error = xlog_unpack_data(rhead, offset, log);
- if (error)
- goto bread_err2;
-
- error = xlog_recover_process_data(log,
- rhash, rhead, offset, pass);
- if (error)
- goto bread_err2;
- blk_no += bblks + hblks;
- }
- } else {
+ blk_no = tail_blk;
+ if (tail_blk > head_blk) {
/*
* Perform recovery around the end of the physical log.
* When the head is not on the same cycle number as the tail,
- * we can't do a sequential recovery as above.
+ * we can't do a sequential recovery.
*/
- blk_no = tail_blk;
while (blk_no < log->l_logBBsize) {
/*
* Check for header wrapping around physical end-of-log
@@ -4280,34 +4252,35 @@ xlog_do_recovery_pass(
ASSERT(blk_no >= log->l_logBBsize);
blk_no -= log->l_logBBsize;
+ }
- /* read first part of physical log */
- while (blk_no < head_blk) {
- error = xlog_bread(log, blk_no, hblks, hbp, &offset);
- if (error)
- goto bread_err2;
+ /* read first part of physical log */
+ while (blk_no < head_blk) {
+ error = xlog_bread(log, blk_no, hblks, hbp, &offset);
+ if (error)
+ goto bread_err2;
- rhead = (xlog_rec_header_t *)offset;
- error = xlog_valid_rec_header(log, rhead, blk_no);
- if (error)
- goto bread_err2;
+ rhead = (xlog_rec_header_t *)offset;
+ error = xlog_valid_rec_header(log, rhead, blk_no);
+ if (error)
+ goto bread_err2;
- bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
- error = xlog_bread(log, blk_no+hblks, bblks, dbp,
- &offset);
- if (error)
- goto bread_err2;
+ /* blocks in data section */
+ bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
+ error = xlog_bread(log, blk_no+hblks, bblks, dbp,
+ &offset);
+ if (error)
+ goto bread_err2;
- error = xlog_unpack_data(rhead, offset, log);
- if (error)
- goto bread_err2;
+ error = xlog_unpack_data(rhead, offset, log);
+ if (error)
+ goto bread_err2;
- error = xlog_recover_process_data(log, rhash,
- rhead, offset, pass);
- if (error)
- goto bread_err2;
- blk_no += bblks + hblks;
- }
+ error = xlog_recover_process_data(log, rhash,
+ rhead, offset, pass);
+ if (error)
+ goto bread_err2;
+ blk_no += bblks + hblks;
}
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