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md/raid1: factor several functions out or raid1d()
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raid1d is too big with several deep branches.
So separate them out into their own functions.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
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NeilBrown committed Jul 28, 2011
1 parent 3a9f28a commit 62096bc
Showing 1 changed file with 151 additions and 159 deletions.
310 changes: 151 additions & 159 deletions drivers/md/raid1.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1861,21 +1861,160 @@ static int narrow_write_error(r1bio_t *r1_bio, int i)
return ok;
}

static void handle_sync_write_finished(conf_t *conf, r1bio_t *r1_bio)
{
int m;
int s = r1_bio->sectors;
for (m = 0; m < conf->raid_disks ; m++) {
mdk_rdev_t *rdev = conf->mirrors[m].rdev;
struct bio *bio = r1_bio->bios[m];
if (bio->bi_end_io == NULL)
continue;
if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
test_bit(R1BIO_MadeGood, &r1_bio->state)) {
rdev_clear_badblocks(rdev, r1_bio->sector, s);
}
if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
test_bit(R1BIO_WriteError, &r1_bio->state)) {
if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
md_error(conf->mddev, rdev);
}
}
put_buf(r1_bio);
md_done_sync(conf->mddev, s, 1);
}

static void handle_write_finished(conf_t *conf, r1bio_t *r1_bio)
{
int m;
for (m = 0; m < conf->raid_disks ; m++)
if (r1_bio->bios[m] == IO_MADE_GOOD) {
mdk_rdev_t *rdev = conf->mirrors[m].rdev;
rdev_clear_badblocks(rdev,
r1_bio->sector,
r1_bio->sectors);
rdev_dec_pending(rdev, conf->mddev);
} else if (r1_bio->bios[m] != NULL) {
/* This drive got a write error. We need to
* narrow down and record precise write
* errors.
*/
if (!narrow_write_error(r1_bio, m)) {
md_error(conf->mddev,
conf->mirrors[m].rdev);
/* an I/O failed, we can't clear the bitmap */
set_bit(R1BIO_Degraded, &r1_bio->state);
}
rdev_dec_pending(conf->mirrors[m].rdev,
conf->mddev);
}
if (test_bit(R1BIO_WriteError, &r1_bio->state))
close_write(r1_bio);
raid_end_bio_io(r1_bio);
}

static void handle_read_error(conf_t *conf, r1bio_t *r1_bio)
{
int disk;
int max_sectors;
mddev_t *mddev = conf->mddev;
struct bio *bio;
char b[BDEVNAME_SIZE];
mdk_rdev_t *rdev;

clear_bit(R1BIO_ReadError, &r1_bio->state);
/* we got a read error. Maybe the drive is bad. Maybe just
* the block and we can fix it.
* We freeze all other IO, and try reading the block from
* other devices. When we find one, we re-write
* and check it that fixes the read error.
* This is all done synchronously while the array is
* frozen
*/
if (mddev->ro == 0) {
freeze_array(conf);
fix_read_error(conf, r1_bio->read_disk,
r1_bio->sector, r1_bio->sectors);
unfreeze_array(conf);
} else
md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);

bio = r1_bio->bios[r1_bio->read_disk];
bdevname(bio->bi_bdev, b);
read_more:
disk = read_balance(conf, r1_bio, &max_sectors);
if (disk == -1) {
printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
" read error for block %llu\n",
mdname(mddev), b, (unsigned long long)r1_bio->sector);
raid_end_bio_io(r1_bio);
} else {
const unsigned long do_sync
= r1_bio->master_bio->bi_rw & REQ_SYNC;
if (bio) {
r1_bio->bios[r1_bio->read_disk] =
mddev->ro ? IO_BLOCKED : NULL;
bio_put(bio);
}
r1_bio->read_disk = disk;
bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
r1_bio->bios[r1_bio->read_disk] = bio;
rdev = conf->mirrors[disk].rdev;
printk_ratelimited(KERN_ERR
"md/raid1:%s: redirecting sector %llu"
" to other mirror: %s\n",
mdname(mddev),
(unsigned long long)r1_bio->sector,
bdevname(rdev->bdev, b));
bio->bi_sector = r1_bio->sector + rdev->data_offset;
bio->bi_bdev = rdev->bdev;
bio->bi_end_io = raid1_end_read_request;
bio->bi_rw = READ | do_sync;
bio->bi_private = r1_bio;
if (max_sectors < r1_bio->sectors) {
/* Drat - have to split this up more */
struct bio *mbio = r1_bio->master_bio;
int sectors_handled = (r1_bio->sector + max_sectors
- mbio->bi_sector);
r1_bio->sectors = max_sectors;
spin_lock_irq(&conf->device_lock);
if (mbio->bi_phys_segments == 0)
mbio->bi_phys_segments = 2;
else
mbio->bi_phys_segments++;
spin_unlock_irq(&conf->device_lock);
generic_make_request(bio);
bio = NULL;

r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);

r1_bio->master_bio = mbio;
r1_bio->sectors = (mbio->bi_size >> 9)
- sectors_handled;
r1_bio->state = 0;
set_bit(R1BIO_ReadError, &r1_bio->state);
r1_bio->mddev = mddev;
r1_bio->sector = mbio->bi_sector + sectors_handled;

goto read_more;
} else
generic_make_request(bio);
}
}

static void raid1d(mddev_t *mddev)
{
r1bio_t *r1_bio;
struct bio *bio;
unsigned long flags;
conf_t *conf = mddev->private;
struct list_head *head = &conf->retry_list;
mdk_rdev_t *rdev;
struct blk_plug plug;

md_check_recovery(mddev);

blk_start_plug(&plug);
for (;;) {
char b[BDEVNAME_SIZE];

if (atomic_read(&mddev->plug_cnt) == 0)
flush_pending_writes(conf);
Expand All @@ -1894,168 +2033,21 @@ static void raid1d(mddev_t *mddev)
conf = mddev->private;
if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
test_bit(R1BIO_WriteError, &r1_bio->state)) {
int m;
int s = r1_bio->sectors;
for (m = 0; m < conf->raid_disks ; m++) {
mdk_rdev_t *rdev
= conf->mirrors[m].rdev;
struct bio *bio = r1_bio->bios[m];
if (bio->bi_end_io == NULL)
continue;
if (test_bit(BIO_UPTODATE,
&bio->bi_flags) &&
test_bit(R1BIO_MadeGood,
&r1_bio->state)) {
rdev_clear_badblocks(
rdev,
r1_bio->sector,
r1_bio->sectors);
}
if (!test_bit(BIO_UPTODATE,
&bio->bi_flags) &&
test_bit(R1BIO_WriteError,
&r1_bio->state)) {
if (!rdev_set_badblocks(
rdev,
r1_bio->sector,
r1_bio->sectors, 0))
md_error(mddev, rdev);
}
}
put_buf(r1_bio);
md_done_sync(mddev, s, 1);
} else
test_bit(R1BIO_WriteError, &r1_bio->state))
handle_sync_write_finished(conf, r1_bio);
else
sync_request_write(mddev, r1_bio);
} else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
test_bit(R1BIO_WriteError, &r1_bio->state)) {
int m;
for (m = 0; m < conf->raid_disks ; m++)
if (r1_bio->bios[m] == IO_MADE_GOOD) {
rdev = conf->mirrors[m].rdev;
rdev_clear_badblocks(
rdev,
r1_bio->sector,
r1_bio->sectors);
rdev_dec_pending(rdev, mddev);
} else if (r1_bio->bios[m] != NULL) {
/* This drive got a write error. We
* need to narrow down and record
* precise write errors.
*/
if (!narrow_write_error(r1_bio, m)) {
md_error(mddev,
conf->mirrors[m].rdev);
/* an I/O failed, we can't clear
* the bitmap */
set_bit(R1BIO_Degraded,
&r1_bio->state);
}
rdev_dec_pending(conf->mirrors[m].rdev,
mddev);
}
if (test_bit(R1BIO_WriteError, &r1_bio->state))
close_write(r1_bio);
raid_end_bio_io(r1_bio);
} else if (test_bit(R1BIO_ReadError, &r1_bio->state)) {
int disk;
int max_sectors;

clear_bit(R1BIO_ReadError, &r1_bio->state);
/* we got a read error. Maybe the drive is bad. Maybe just
* the block and we can fix it.
* We freeze all other IO, and try reading the block from
* other devices. When we find one, we re-write
* and check it that fixes the read error.
* This is all done synchronously while the array is
* frozen
*/
if (mddev->ro == 0) {
freeze_array(conf);
fix_read_error(conf, r1_bio->read_disk,
r1_bio->sector,
r1_bio->sectors);
unfreeze_array(conf);
} else
md_error(mddev,
conf->mirrors[r1_bio->read_disk].rdev);

bio = r1_bio->bios[r1_bio->read_disk];
bdevname(bio->bi_bdev, b);
read_more:
disk = read_balance(conf, r1_bio, &max_sectors);
if (disk == -1) {
printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
" read error for block %llu\n",
mdname(mddev), b,
(unsigned long long)r1_bio->sector);
raid_end_bio_io(r1_bio);
} else {
const unsigned long do_sync = r1_bio->master_bio->bi_rw & REQ_SYNC;
if (bio) {
r1_bio->bios[r1_bio->read_disk] =
mddev->ro ? IO_BLOCKED : NULL;
bio_put(bio);
}
r1_bio->read_disk = disk;
bio = bio_clone_mddev(r1_bio->master_bio,
GFP_NOIO, mddev);
md_trim_bio(bio,
r1_bio->sector - bio->bi_sector,
max_sectors);
r1_bio->bios[r1_bio->read_disk] = bio;
rdev = conf->mirrors[disk].rdev;
printk_ratelimited(
KERN_ERR
"md/raid1:%s: redirecting sector %llu"
" to other mirror: %s\n",
mdname(mddev),
(unsigned long long)r1_bio->sector,
bdevname(rdev->bdev, b));
bio->bi_sector = r1_bio->sector + rdev->data_offset;
bio->bi_bdev = rdev->bdev;
bio->bi_end_io = raid1_end_read_request;
bio->bi_rw = READ | do_sync;
bio->bi_private = r1_bio;
if (max_sectors < r1_bio->sectors) {
/* Drat - have to split this up more */
struct bio *mbio = r1_bio->master_bio;
int sectors_handled =
r1_bio->sector + max_sectors
- mbio->bi_sector;
r1_bio->sectors = max_sectors;
spin_lock_irq(&conf->device_lock);
if (mbio->bi_phys_segments == 0)
mbio->bi_phys_segments = 2;
else
mbio->bi_phys_segments++;
spin_unlock_irq(&conf->device_lock);
generic_make_request(bio);
bio = NULL;

r1_bio = mempool_alloc(conf->r1bio_pool,
GFP_NOIO);

r1_bio->master_bio = mbio;
r1_bio->sectors = (mbio->bi_size >> 9)
- sectors_handled;
r1_bio->state = 0;
set_bit(R1BIO_ReadError,
&r1_bio->state);
r1_bio->mddev = mddev;
r1_bio->sector = mbio->bi_sector
+ sectors_handled;

goto read_more;
} else
generic_make_request(bio);
}
} else {
test_bit(R1BIO_WriteError, &r1_bio->state))
handle_write_finished(conf, r1_bio);
else if (test_bit(R1BIO_ReadError, &r1_bio->state))
handle_read_error(conf, r1_bio);
else
/* just a partial read to be scheduled from separate
* context
*/
generic_make_request(r1_bio->bios[r1_bio->read_disk]);
}

cond_resched();
if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
md_check_recovery(mddev);
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