[PATCH] md: Factor out part of raid1d into a separate function

raid1d 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/raid1.c b/drivers/md/raid1.c
index 2817c47..13b59e6 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1368,6 +1368,95 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
  *     3.      Performs writes following reads for array syncronising.
  */
 
+static void fix_read_error(conf_t *conf, int read_disk,
+                          sector_t sect, int sectors)
+{
+       mddev_t *mddev = conf->mddev;
+       while(sectors) {
+               int s = sectors;
+               int d = read_disk;
+               int success = 0;
+               int start;
+               mdk_rdev_t *rdev;
+
+               if (s > (PAGE_SIZE>>9))
+                       s = PAGE_SIZE >> 9;
+
+               do {
+                       /* Note: no rcu protection needed here
+                        * as this is synchronous in the raid1d thread
+                        * which is the thread that might remove
+                        * a device.  If raid1d ever becomes multi-threaded....
+                        */
+                       rdev = conf->mirrors[d].rdev;
+                       if (rdev &&
+                           test_bit(In_sync, &rdev->flags) &&
+                           sync_page_io(rdev->bdev,
+                                        sect + rdev->data_offset,
+                                        s<<9,
+                                        conf->tmppage, READ))
+                               success = 1;
+                       else {
+                               d++;
+                               if (d == conf->raid_disks)
+                                       d = 0;
+                       }
+               } while (!success && d != read_disk);
+
+               if (!success) {
+                       /* Cannot read from anywhere -- bye bye array */
+                       md_error(mddev, conf->mirrors[read_disk].rdev);
+                       break;
+               }
+               /* write it back and re-read */
+               start = d;
+               while (d != read_disk) {
+                       if (d==0)
+                               d = conf->raid_disks;
+                       d--;
+                       rdev = conf->mirrors[d].rdev;
+                       if (rdev &&
+                           test_bit(In_sync, &rdev->flags)) {
+                               if (sync_page_io(rdev->bdev,
+                                                sect + rdev->data_offset,
+                                                s<<9, conf->tmppage, WRITE)
+                                   == 0)
+                                       /* Well, this device is dead */
+                                       md_error(mddev, rdev);
+                       }
+               }
+               d = start;
+               while (d != read_disk) {
+                       char b[BDEVNAME_SIZE];
+                       if (d==0)
+                               d = conf->raid_disks;
+                       d--;
+                       rdev = conf->mirrors[d].rdev;
+                       if (rdev &&
+                           test_bit(In_sync, &rdev->flags)) {
+                               if (sync_page_io(rdev->bdev,
+                                                sect + rdev->data_offset,
+                                                s<<9, conf->tmppage, READ)
+                                   == 0)
+                                       /* Well, this device is dead */
+                                       md_error(mddev, rdev);
+                               else {
+                                       atomic_add(s, &rdev->corrected_errors);
+                                       printk(KERN_INFO
+                                              "raid1:%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));
+                               }
+                       }
+               }
+               sectors -= s;
+               sect += s;
+       }
+}
+
 static void raid1d(mddev_t *mddev)
 {
        r1bio_t *r1_bio;
@@ -1460,86 +1549,14 @@ static void raid1d(mddev_t *mddev)
                         * This is all done synchronously while the array is
                         * frozen
                         */
-                       sector_t sect = r1_bio->sector;
-                       int sectors = r1_bio->sectors;
-                       freeze_array(conf);
-                       if (mddev->ro == 0) while(sectors) {
-                               int s = sectors;
-                               int d = r1_bio->read_disk;
-                               int success = 0;
-
-                               if (s > (PAGE_SIZE>>9))
-                                       s = PAGE_SIZE >> 9;
-
-                               do {
-                                       /* Note: no rcu protection needed here
-                                        * as this is synchronous in the raid1d thread
-                                        * which is the thread that might remove
-                                        * a device.  If raid1d ever becomes multi-threaded....
-                                        */
-                                       rdev = conf->mirrors[d].rdev;
-                                       if (rdev &&
-                                           test_bit(In_sync, &rdev->flags) &&
-                                           sync_page_io(rdev->bdev,
-                                                        sect + rdev->data_offset,
-                                                        s<<9,
-                                                        conf->tmppage, READ))
-                                               success = 1;
-                                       else {
-                                               d++;
-                                               if (d == conf->raid_disks)
-                                                       d = 0;
-                                       }
-                               } while (!success && d != r1_bio->read_disk);
-
-                               if (success) {
-                                       /* write it back and re-read */
-                                       int start = d;
-                                       while (d != r1_bio->read_disk) {
-                                               if (d==0)
-                                                       d = conf->raid_disks;
-                                               d--;
-                                               rdev = conf->mirrors[d].rdev;
-                                               if (rdev &&
-                                                   test_bit(In_sync, &rdev->flags)) {
-                                                       if (sync_page_io(rdev->bdev,
-                                                                        sect + rdev->data_offset,
-                                                                        s<<9, conf->tmppage, WRITE) == 0)
-                                                               /* Well, this device is dead */
-                                                               md_error(mddev, rdev);
-                                               }
-                                       }
-                                       d = start;
-                                       while (d != r1_bio->read_disk) {
-                                               if (d==0)
-                                                       d = conf->raid_disks;
-                                               d--;
-                                               rdev = conf->mirrors[d].rdev;
-                                               if (rdev &&
-                                                   test_bit(In_sync, &rdev->flags)) {
-                                                       if (sync_page_io(rdev->bdev,
-                                                                        sect + rdev->data_offset,
-                                                                        s<<9, conf->tmppage, READ) == 0)
-                                                               /* Well, this device is dead */
-                                                               md_error(mddev, rdev);
-                                                       else {
-                                                               atomic_add(s, &rdev->corrected_errors);
-                                                               printk(KERN_INFO "raid1:%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));
-                                                       }
-                                               }
-                                       }
-                               } else {
-                                       /* Cannot read from anywhere -- bye bye array */
-                                       md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
-                                       break;
-                               }
-                               sectors -= s;
-                               sect += s;
+                       if (mddev->ro == 0) {
+                               freeze_array(conf);
+                               fix_read_error(conf, r1_bio->read_disk,
+                                              r1_bio->sector,
+                                              r1_bio->sectors);
+                               unfreeze_array(conf);
                        }
 
-                       unfreeze_array(conf);
-
                        bio = r1_bio->bios[r1_bio->read_disk];
                        if ((disk=read_balance(conf, r1_bio)) == -1) {
                                printk(KERN_ALERT "raid1: %s: unrecoverable I/O"