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md/raid1: split out two sub-functions from sync_request_write
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sync_request_write is too big and too deep.
So split out two self-contains bits of functionality into separate
function.

Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown committed May 11, 2011
1 parent 6f8d0c7 commit a68e587
Showing 1 changed file with 192 additions and 173 deletions.
365 changes: 192 additions & 173 deletions drivers/md/raid1.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1181,194 +1181,213 @@ static void end_sync_write(struct bio *bio, int error)
}
}

static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
static int fix_sync_read_error(r1bio_t *r1_bio)
{
/* Try some synchronous reads of other devices to get
* good data, much like with normal read errors. Only
* read into the pages we already have so we don't
* need to re-issue the read request.
* We don't need to freeze the array, because being in an
* active sync request, there is no normal IO, and
* no overlapping syncs.
*/
mddev_t *mddev = r1_bio->mddev;
conf_t *conf = mddev->private;
int i;
int disks = conf->raid_disks;
struct bio *bio, *wbio;
struct bio *bio = r1_bio->bios[r1_bio->read_disk];
sector_t sect = r1_bio->sector;
int sectors = r1_bio->sectors;
int idx = 0;

bio = r1_bio->bios[r1_bio->read_disk];


if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
/* We have read all readable devices. If we haven't
* got the block, then there is no hope left.
* If we have, then we want to do a comparison
* and skip the write if everything is the same.
* If any blocks failed to read, then we need to
* attempt an over-write
*/
int primary;
if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
for (i=0; i<mddev->raid_disks; i++)
if (r1_bio->bios[i]->bi_end_io == end_sync_read)
md_error(mddev, conf->mirrors[i].rdev);
while(sectors) {
int s = sectors;
int d = r1_bio->read_disk;
int success = 0;
mdk_rdev_t *rdev;

md_done_sync(mddev, r1_bio->sectors, 1);
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
do {
if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
/* No rcu protection needed here devices
* can only be removed when no resync is
* active, and resync is currently active
*/
rdev = conf->mirrors[d].rdev;
if (sync_page_io(rdev,
sect,
s<<9,
bio->bi_io_vec[idx].bv_page,
READ, false)) {
success = 1;
break;
}
}
d++;
if (d == conf->raid_disks)
d = 0;
} while (!success && d != r1_bio->read_disk);

if (success) {
int start = d;
/* write it back and re-read */
set_bit(R1BIO_Uptodate, &r1_bio->state);
while (d != r1_bio->read_disk) {
if (d == 0)
d = conf->raid_disks;
d--;
if (r1_bio->bios[d]->bi_end_io != end_sync_read)
continue;
rdev = conf->mirrors[d].rdev;
atomic_add(s, &rdev->corrected_errors);
if (sync_page_io(rdev,
sect,
s<<9,
bio->bi_io_vec[idx].bv_page,
WRITE, false) == 0)
md_error(mddev, rdev);
}
d = start;
while (d != r1_bio->read_disk) {
if (d == 0)
d = conf->raid_disks;
d--;
if (r1_bio->bios[d]->bi_end_io != end_sync_read)
continue;
rdev = conf->mirrors[d].rdev;
if (sync_page_io(rdev,
sect,
s<<9,
bio->bi_io_vec[idx].bv_page,
READ, false) == 0)
md_error(mddev, rdev);
}
} else {
char b[BDEVNAME_SIZE];
/* Cannot read from anywhere, array is toast */
md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
" for block %llu\n",
mdname(mddev),
bdevname(bio->bi_bdev, b),
(unsigned long long)r1_bio->sector);
md_done_sync(mddev, r1_bio->sectors, 0);
put_buf(r1_bio);
return;
return 0;
}
for (primary=0; primary<mddev->raid_disks; primary++)
if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
r1_bio->bios[primary]->bi_end_io = NULL;
rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
break;
}
r1_bio->read_disk = primary;
sectors -= s;
sect += s;
idx ++;
}
return 1;
}

static int process_checks(r1bio_t *r1_bio)
{
/* We have read all readable devices. If we haven't
* got the block, then there is no hope left.
* If we have, then we want to do a comparison
* and skip the write if everything is the same.
* If any blocks failed to read, then we need to
* attempt an over-write
*/
mddev_t *mddev = r1_bio->mddev;
conf_t *conf = mddev->private;
int primary;
int i;

if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
for (i=0; i<mddev->raid_disks; i++)
if (r1_bio->bios[i]->bi_end_io == end_sync_read) {
int j;
int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
struct bio *pbio = r1_bio->bios[primary];
struct bio *sbio = r1_bio->bios[i];

if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
for (j = vcnt; j-- ; ) {
struct page *p, *s;
p = pbio->bi_io_vec[j].bv_page;
s = sbio->bi_io_vec[j].bv_page;
if (memcmp(page_address(p),
page_address(s),
PAGE_SIZE))
break;
}
} else
j = 0;
if (j >= 0)
mddev->resync_mismatches += r1_bio->sectors;
if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
&& test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
sbio->bi_end_io = NULL;
rdev_dec_pending(conf->mirrors[i].rdev, mddev);
} else {
/* fixup the bio for reuse */
int size;
sbio->bi_vcnt = vcnt;
sbio->bi_size = r1_bio->sectors << 9;
sbio->bi_idx = 0;
sbio->bi_phys_segments = 0;
sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
sbio->bi_flags |= 1 << BIO_UPTODATE;
sbio->bi_next = NULL;
sbio->bi_sector = r1_bio->sector +
conf->mirrors[i].rdev->data_offset;
sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
size = sbio->bi_size;
for (j = 0; j < vcnt ; j++) {
struct bio_vec *bi;
bi = &sbio->bi_io_vec[j];
bi->bv_offset = 0;
if (size > PAGE_SIZE)
bi->bv_len = PAGE_SIZE;
else
bi->bv_len = size;
size -= PAGE_SIZE;
memcpy(page_address(bi->bv_page),
page_address(pbio->bi_io_vec[j].bv_page),
PAGE_SIZE);
}
if (r1_bio->bios[i]->bi_end_io == end_sync_read)
md_error(mddev, conf->mirrors[i].rdev);

}
}
md_done_sync(mddev, r1_bio->sectors, 1);
put_buf(r1_bio);
return -1;
}
if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
/* ouch - failed to read all of that.
* Try some synchronous reads of other devices to get
* good data, much like with normal read errors. Only
* read into the pages we already have so we don't
* need to re-issue the read request.
* We don't need to freeze the array, because being in an
* active sync request, there is no normal IO, and
* no overlapping syncs.
*/
sector_t sect = r1_bio->sector;
int sectors = r1_bio->sectors;
int idx = 0;

while(sectors) {
int s = sectors;
int d = r1_bio->read_disk;
int success = 0;
mdk_rdev_t *rdev;

if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
do {
if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
/* No rcu protection needed here devices
* can only be removed when no resync is
* active, and resync is currently active
*/
rdev = conf->mirrors[d].rdev;
if (sync_page_io(rdev,
sect,
s<<9,
bio->bi_io_vec[idx].bv_page,
READ, false)) {
success = 1;
for (primary=0; primary<mddev->raid_disks; primary++)
if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
r1_bio->bios[primary]->bi_end_io = NULL;
rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
break;
}
r1_bio->read_disk = primary;
for (i=0; i<mddev->raid_disks; i++)
if (r1_bio->bios[i]->bi_end_io == end_sync_read) {
int j;
int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
struct bio *pbio = r1_bio->bios[primary];
struct bio *sbio = r1_bio->bios[i];

if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
for (j = vcnt; j-- ; ) {
struct page *p, *s;
p = pbio->bi_io_vec[j].bv_page;
s = sbio->bi_io_vec[j].bv_page;
if (memcmp(page_address(p),
page_address(s),
PAGE_SIZE))
break;
}
}
d++;
if (d == conf->raid_disks)
d = 0;
} while (!success && d != r1_bio->read_disk);

if (success) {
int start = d;
/* write it back and re-read */
set_bit(R1BIO_Uptodate, &r1_bio->state);
while (d != r1_bio->read_disk) {
if (d == 0)
d = conf->raid_disks;
d--;
if (r1_bio->bios[d]->bi_end_io != end_sync_read)
continue;
rdev = conf->mirrors[d].rdev;
atomic_add(s, &rdev->corrected_errors);
if (sync_page_io(rdev,
sect,
s<<9,
bio->bi_io_vec[idx].bv_page,
WRITE, false) == 0)
md_error(mddev, rdev);
}
d = start;
while (d != r1_bio->read_disk) {
if (d == 0)
d = conf->raid_disks;
d--;
if (r1_bio->bios[d]->bi_end_io != end_sync_read)
continue;
rdev = conf->mirrors[d].rdev;
if (sync_page_io(rdev,
sect,
s<<9,
bio->bi_io_vec[idx].bv_page,
READ, false) == 0)
md_error(mddev, rdev);
}
} else
j = 0;
if (j >= 0)
mddev->resync_mismatches += r1_bio->sectors;
if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
&& test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
sbio->bi_end_io = NULL;
rdev_dec_pending(conf->mirrors[i].rdev, mddev);
} else {
char b[BDEVNAME_SIZE];
/* Cannot read from anywhere, array is toast */
md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
" for block %llu\n",
mdname(mddev),
bdevname(bio->bi_bdev, b),
(unsigned long long)r1_bio->sector);
md_done_sync(mddev, r1_bio->sectors, 0);
put_buf(r1_bio);
return;
/* fixup the bio for reuse */
int size;
sbio->bi_vcnt = vcnt;
sbio->bi_size = r1_bio->sectors << 9;
sbio->bi_idx = 0;
sbio->bi_phys_segments = 0;
sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
sbio->bi_flags |= 1 << BIO_UPTODATE;
sbio->bi_next = NULL;
sbio->bi_sector = r1_bio->sector +
conf->mirrors[i].rdev->data_offset;
sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
size = sbio->bi_size;
for (j = 0; j < vcnt ; j++) {
struct bio_vec *bi;
bi = &sbio->bi_io_vec[j];
bi->bv_offset = 0;
if (size > PAGE_SIZE)
bi->bv_len = PAGE_SIZE;
else
bi->bv_len = size;
size -= PAGE_SIZE;
memcpy(page_address(bi->bv_page),
page_address(pbio->bi_io_vec[j].bv_page),
PAGE_SIZE);
}

}
sectors -= s;
sect += s;
idx ++;
}
}
return 0;
}

static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
{
conf_t *conf = mddev->private;
int i;
int disks = conf->raid_disks;
struct bio *bio, *wbio;

bio = r1_bio->bios[r1_bio->read_disk];


if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
if (process_checks(r1_bio) < 0)
return;

if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
/* ouch - failed to read all of that. */
if (!fix_sync_read_error(r1_bio))
return;
/*
* schedule writes
*/
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