#include "bitmap.h"
#define DEBUG 0
-#if DEBUG
-#define PRINTK(x...) printk(x)
-#else
-#define PRINTK(x...)
-#endif
+#define PRINTK(x...) do { if (DEBUG) printk(x); } while (0)
/*
* Number of guaranteed r1bios in case of extreme VM load:
{
conf_t *conf = r1_bio->mddev->private;
- /*
- * Wake up any possible resync thread that waits for the device
- * to go idle.
- */
- allow_barrier(conf);
-
put_all_bios(conf, r1_bio);
mempool_free(r1_bio, conf->r1bio_pool);
}
* operation and are ready to return a success/failure code to the buffer
* cache layer.
*/
+static void call_bio_endio(r1bio_t *r1_bio)
+{
+ struct bio *bio = r1_bio->master_bio;
+ int done;
+ conf_t *conf = r1_bio->mddev->private;
+
+ if (bio->bi_phys_segments) {
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio->bi_phys_segments--;
+ done = (bio->bi_phys_segments == 0);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ } else
+ done = 1;
+
+ if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+ if (done) {
+ bio_endio(bio, 0);
+ /*
+ * Wake up any possible resync thread that waits for the device
+ * to go idle.
+ */
+ allow_barrier(conf);
+ }
+}
+
static void raid_end_bio_io(r1bio_t *r1_bio)
{
struct bio *bio = r1_bio->master_bio;
(unsigned long long) bio->bi_sector +
(bio->bi_size >> 9) - 1);
- bio_endio(bio,
- test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
+ call_bio_endio(r1_bio);
}
free_r1bio(r1_bio);
}
bdevname(conf->mirrors[mirror].rdev->bdev,
b),
(unsigned long long)r1_bio->sector);
+ set_bit(R1BIO_ReadError, &r1_bio->state);
reschedule_retry(r1_bio);
}
(unsigned long long) mbio->bi_sector,
(unsigned long long) mbio->bi_sector +
(mbio->bi_size >> 9) - 1);
- bio_endio(mbio, 0);
+ call_bio_endio(r1_bio);
}
}
}
*
* The rdev for the device selected will have nr_pending incremented.
*/
-static int read_balance(conf_t *conf, r1bio_t *r1_bio)
+static int read_balance(conf_t *conf, r1bio_t *r1_bio, int *max_sectors)
{
const sector_t this_sector = r1_bio->sector;
- const int sectors = r1_bio->sectors;
+ int sectors;
+ int best_good_sectors;
int start_disk;
int best_disk;
int i;
* We take the first readable disk when above the resync window.
*/
retry:
+ sectors = r1_bio->sectors;
best_disk = -1;
best_dist = MaxSector;
+ best_good_sectors = 0;
+
if (conf->mddev->recovery_cp < MaxSector &&
(this_sector + sectors >= conf->next_resync)) {
choose_first = 1;
for (i = 0 ; i < conf->raid_disks ; i++) {
sector_t dist;
+ sector_t first_bad;
+ int bad_sectors;
+
int disk = start_disk + i;
if (disk >= conf->raid_disks)
disk -= conf->raid_disks;
/* This is a reasonable device to use. It might
* even be best.
*/
+ if (is_badblock(rdev, this_sector, sectors,
+ &first_bad, &bad_sectors)) {
+ if (best_dist < MaxSector)
+ /* already have a better device */
+ continue;
+ if (first_bad <= this_sector) {
+ /* cannot read here. If this is the 'primary'
+ * device, then we must not read beyond
+ * bad_sectors from another device..
+ */
+ bad_sectors -= (this_sector - first_bad);
+ if (choose_first && sectors > bad_sectors)
+ sectors = bad_sectors;
+ if (best_good_sectors > sectors)
+ best_good_sectors = sectors;
+
+ } else {
+ sector_t good_sectors = first_bad - this_sector;
+ if (good_sectors > best_good_sectors) {
+ best_good_sectors = good_sectors;
+ best_disk = disk;
+ }
+ if (choose_first)
+ break;
+ }
+ continue;
+ } else
+ best_good_sectors = sectors;
+
dist = abs(this_sector - conf->mirrors[disk].head_position);
if (choose_first
/* Don't change to another disk for sequential reads */
rdev_dec_pending(rdev, conf->mddev);
goto retry;
}
+ sectors = best_good_sectors;
conf->next_seq_sect = this_sector + sectors;
conf->last_used = best_disk;
}
rcu_read_unlock();
+ *max_sectors = sectors;
return best_disk;
}
r1_bio->mddev = mddev;
r1_bio->sector = bio->bi_sector;
+ /* We might need to issue multiple reads to different
+ * devices if there are bad blocks around, so we keep
+ * track of the number of reads in bio->bi_phys_segments.
+ * If this is 0, there is only one r1_bio and no locking
+ * will be needed when requests complete. If it is
+ * non-zero, then it is the number of not-completed requests.
+ */
+ bio->bi_phys_segments = 0;
+ clear_bit(BIO_SEG_VALID, &bio->bi_flags);
+
if (rw == READ) {
/*
* read balancing logic:
*/
- int rdisk = read_balance(conf, r1_bio);
+ int max_sectors;
+ int rdisk;
+
+read_again:
+ rdisk = read_balance(conf, r1_bio, &max_sectors);
if (rdisk < 0) {
/* couldn't find anywhere to read from */
r1_bio->read_disk = rdisk;
read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
+ max_sectors);
r1_bio->bios[rdisk] = read_bio;
read_bio->bi_rw = READ | do_sync;
read_bio->bi_private = r1_bio;
- generic_make_request(read_bio);
+ if (max_sectors < r1_bio->sectors) {
+ /* could not read all from this device, so we will
+ * need another r1_bio.
+ */
+ int sectors_handled;
+
+ sectors_handled = (r1_bio->sector + max_sectors
+ - bio->bi_sector);
+ r1_bio->sectors = max_sectors;
+ spin_lock_irq(&conf->device_lock);
+ if (bio->bi_phys_segments == 0)
+ bio->bi_phys_segments = 2;
+ else
+ bio->bi_phys_segments++;
+ spin_unlock_irq(&conf->device_lock);
+ /* Cannot call generic_make_request directly
+ * as that will be queued in __make_request
+ * and subsequent mempool_alloc might block waiting
+ * for it. So hand bio over to raid1d.
+ */
+ reschedule_retry(r1_bio);
+
+ r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
+
+ r1_bio->master_bio = bio;
+ r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
+ r1_bio->state = 0;
+ r1_bio->mddev = mddev;
+ r1_bio->sector = bio->bi_sector + sectors_handled;
+ goto read_again;
+ } else
+ generic_make_request(read_bio);
return 0;
}
goto retry_write;
}
- BUG_ON(targets == 0); /* we never fail the last device */
-
if (targets < conf->raid_disks) {
/* array is degraded, we will not clear the bitmap
* on I/O completion (see raid1_end_write_request) */
*
* 1. Retries failed read operations on working mirrors.
* 2. Updates the raid superblock when problems encounter.
- * 3. Performs writes following reads for array syncronising.
+ * 3. Performs writes following reads for array synchronising.
*/
static void fix_read_error(conf_t *conf, int read_disk,
* which is the thread that might remove
* a device. If raid1d ever becomes multi-threaded....
*/
+ sector_t first_bad;
+ int bad_sectors;
+
rdev = conf->mirrors[d].rdev;
if (rdev &&
test_bit(In_sync, &rdev->flags) &&
+ is_badblock(rdev, sect, s,
+ &first_bad, &bad_sectors) == 0 &&
sync_page_io(rdev, sect, s<<9,
conf->tmppage, READ, false))
success = 1;
conf = mddev->private;
if (test_bit(R1BIO_IsSync, &r1_bio->state))
sync_request_write(mddev, r1_bio);
- else {
+ 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
conf->mirrors[r1_bio->read_disk].rdev);
bio = r1_bio->bios[r1_bio->read_disk];
- if ((disk=read_balance(conf, r1_bio)) == -1) {
+ 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),
- bdevname(bio->bi_bdev,b),
+ 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;
- r1_bio->bios[r1_bio->read_disk] =
- mddev->ro ? IO_BLOCKED : NULL;
+ if (bio) {
+ r1_bio->bios[r1_bio->read_disk] =
+ mddev->ro ? IO_BLOCKED : NULL;
+ bio_put(bio);
+ }
r1_bio->read_disk = disk;
- bio_put(bio);
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(
bio->bi_end_io = raid1_end_read_request;
bio->bi_rw = READ | do_sync;
bio->bi_private = r1_bio;
- generic_make_request(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 {
+ /* just a partial read to be scheduled from separate
+ * context
+ */
+ generic_make_request(r1_bio->bios[r1_bio->read_disk]);
}
cond_resched();
}
projects / linux-beck.git / commitdiff