[PATCH] md: factor out part of raid10d into a separate function.

raid10d has toooo many nested block, so take the fix_read_error functionality
out into a separate function.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 016ddb8..7bf5ce2 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1350,9 +1350,119 @@ static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
  *
  *     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, mddev_t *mddev, r10bio_t *r10_bio)
+{
+       int sect = 0; /* Offset from r10_bio->sector */
+       int sectors = r10_bio->sectors;
+       mdk_rdev_t*rdev;
+       while(sectors) {
+               int s = sectors;
+               int sl = r10_bio->read_slot;
+               int success = 0;
+               int start;
+
+               if (s > (PAGE_SIZE>>9))
+                       s = PAGE_SIZE >> 9;
+
+               rcu_read_lock();
+               do {
+                       int d = r10_bio->devs[sl].devnum;
+                       rdev = rcu_dereference(conf->mirrors[d].rdev);
+                       if (rdev &&
+                           test_bit(In_sync, &rdev->flags)) {
+                               atomic_inc(&rdev->nr_pending);
+                               rcu_read_unlock();
+                               success = sync_page_io(rdev->bdev,
+                                                      r10_bio->devs[sl].addr +
+                                                      sect + rdev->data_offset,
+                                                      s<<9,
+                                                      conf->tmppage, READ);
+                               rdev_dec_pending(rdev, mddev);
+                               rcu_read_lock();
+                               if (success)
+                                       break;
+                       }
+                       sl++;
+                       if (sl == conf->copies)
+                               sl = 0;
+               } while (!success && sl != r10_bio->read_slot);
+               rcu_read_unlock();
+
+               if (!success) {
+                       /* Cannot read from anywhere -- bye bye array */
+                       int dn = r10_bio->devs[r10_bio->read_slot].devnum;
+                       md_error(mddev, conf->mirrors[dn].rdev);
+                       break;
+               }
+
+               start = sl;
+               /* write it back and re-read */
+               rcu_read_lock();
+               while (sl != r10_bio->read_slot) {
+                       int d;
+                       if (sl==0)
+                               sl = conf->copies;
+                       sl--;
+                       d = r10_bio->devs[sl].devnum;
+                       rdev = rcu_dereference(conf->mirrors[d].rdev);
+                       if (rdev &&
+                           test_bit(In_sync, &rdev->flags)) {
+                               atomic_inc(&rdev->nr_pending);
+                               rcu_read_unlock();
+                               atomic_add(s, &rdev->corrected_errors);
+                               if (sync_page_io(rdev->bdev,
+                                                r10_bio->devs[sl].addr +
+                                                sect + rdev->data_offset,
+                                                s<<9, conf->tmppage, WRITE)
+                                   == 0)
+                                       /* Well, this device is dead */
+                                       md_error(mddev, rdev);
+                               rdev_dec_pending(rdev, mddev);
+                               rcu_read_lock();
+                       }
+               }
+               sl = start;
+               while (sl != r10_bio->read_slot) {
+                       int d;
+                       if (sl==0)
+                               sl = conf->copies;
+                       sl--;
+                       d = r10_bio->devs[sl].devnum;
+                       rdev = rcu_dereference(conf->mirrors[d].rdev);
+                       if (rdev &&
+                           test_bit(In_sync, &rdev->flags)) {
+                               char b[BDEVNAME_SIZE];
+                               atomic_inc(&rdev->nr_pending);
+                               rcu_read_unlock();
+                               if (sync_page_io(rdev->bdev,
+                                                r10_bio->devs[sl].addr +
+                                                sect + rdev->data_offset,
+                                                s<<9, conf->tmppage, READ) == 0)
+                                       /* Well, this device is dead */
+                                       md_error(mddev, rdev);
+                               else
+                                       printk(KERN_INFO
+                                              "raid10:%s: read error corrected"
+                                              " (%d sectors at %llu on %s)\n",
+                                              mdname(mddev), s,
+                                              (unsigned long long)sect+
+                                                   rdev->data_offset,
+                                              bdevname(rdev->bdev, b));
+
+                               rdev_dec_pending(rdev, mddev);
+                               rcu_read_lock();
+                       }
+               }
+               rcu_read_unlock();
+
+               sectors -= s;
+               sect += s;
+       }
+}
+
 static void raid10d(mddev_t *mddev)
 {
        r10bio_t *r10_bio;
@@ -1413,105 +1523,12 @@ static void raid10d(mddev_t *mddev)
                         * This is all done synchronously while the array is
                         * frozen.
                         */
-                       int sect = 0; /* Offset from r10_bio->sector */
-                       int sectors = r10_bio->sectors;
-                       freeze_array(conf);
-                       if (mddev->ro == 0) while(sectors) {
-                               int s = sectors;
-                               int sl = r10_bio->read_slot;
-                               int success = 0;
-
-                               if (s > (PAGE_SIZE>>9))
-                                       s = PAGE_SIZE >> 9;
-
-                               rcu_read_lock();
-                               do {
-                                       int d = r10_bio->devs[sl].devnum;
-                                       rdev = rcu_dereference(conf->mirrors[d].rdev);
-                                       if (rdev &&
-                                           test_bit(In_sync, &rdev->flags)) {
-                                               atomic_inc(&rdev->nr_pending);
-                                               rcu_read_unlock();
-                                               success = sync_page_io(rdev->bdev,
-                                                                      r10_bio->devs[sl].addr +
-                                                                      sect + rdev->data_offset,
-                                                                      s<<9,
-                                                                      conf->tmppage, READ);
-                                               rdev_dec_pending(rdev, mddev);
-                                               rcu_read_lock();
-                                               if (success)
-                                                       break;
-                                       }
-                                       sl++;
-                                       if (sl == conf->copies)
-                                               sl = 0;
-                               } while (!success && sl != r10_bio->read_slot);
-                               rcu_read_unlock();
-
-                               if (success) {
-                                       int start = sl;
-                                       /* write it back and re-read */
-                                       rcu_read_lock();
-                                       while (sl != r10_bio->read_slot) {
-                                               int d;
-                                               if (sl==0)
-                                                       sl = conf->copies;
-                                               sl--;
-                                               d = r10_bio->devs[sl].devnum;
-                                               rdev = rcu_dereference(conf->mirrors[d].rdev);
-                                               if (rdev &&
-                                                   test_bit(In_sync, &rdev->flags)) {
-                                                       atomic_inc(&rdev->nr_pending);
-                                                       rcu_read_unlock();
-                                                       atomic_add(s, &rdev->corrected_errors);
-                                                       if (sync_page_io(rdev->bdev,
-                                                                        r10_bio->devs[sl].addr +
-                                                                        sect + rdev->data_offset,
-                                                                        s<<9, conf->tmppage, WRITE) == 0)
-                                                               /* Well, this device is dead */
-                                                               md_error(mddev, rdev);
-                                                       rdev_dec_pending(rdev, mddev);
-                                                       rcu_read_lock();
-                                               }
-                                       }
-                                       sl = start;
-                                       while (sl != r10_bio->read_slot) {
-                                               int d;
-                                               if (sl==0)
-                                                       sl = conf->copies;
-                                               sl--;
-                                               d = r10_bio->devs[sl].devnum;
-                                               rdev = rcu_dereference(conf->mirrors[d].rdev);
-                                               if (rdev &&
-                                                   test_bit(In_sync, &rdev->flags)) {
-                                                       atomic_inc(&rdev->nr_pending);
-                                                       rcu_read_unlock();
-                                                       if (sync_page_io(rdev->bdev,
-                                                                        r10_bio->devs[sl].addr +
-                                                                        sect + rdev->data_offset,
-                                                                        s<<9, conf->tmppage, READ) == 0)
-                                                               /* Well, this device is dead */
-                                                               md_error(mddev, rdev);
-                                                       else
-                                                               printk(KERN_INFO "raid10:%s: read error corrected (%d sectors at %llu on %s)\n",
-                                                                      mdname(mddev), s, (unsigned long long)(sect+rdev->data_offset), bdevname(rdev->bdev, b));
-
-                                                       rdev_dec_pending(rdev, mddev);
-                                                       rcu_read_lock();
-                                               }
-                                       }
-                                       rcu_read_unlock();
-                               } else {
-                                       /* Cannot read from anywhere -- bye bye array */
-                                       md_error(mddev, conf->mirrors[r10_bio->devs[r10_bio->read_slot].devnum].rdev);
-                                       break;
-                               }
-                               sectors -= s;
-                               sect += s;
+                       if (mddev->ro == 0) {
+                               freeze_array(conf);
+                               fix_read_error(conf, mddev, r10_bio);
+                               unfreeze_array(conf);
                        }
 
-                       unfreeze_array(conf);
-
                        bio = r10_bio->devs[r10_bio->read_slot].bio;
                        r10_bio->devs[r10_bio->read_slot].bio =
                                mddev->ro ? IO_BLOCKED : NULL;