[PATCH] md: improve the interface to sync_request
1/ change the return value (which is number-of-sectors synced)
from 'int' to 'sector_t'.
The number of sectors is usually easily small enough to fit
in an int, but if resync needs to abort, it may want to return
the total number of remaining sectors, which could be large.
Also errors cannot be returned as negative numbers now, so use
0 instead
2/ Add a 'skipped' return parameter to allow the array to report
that it skipped the sectors. This allows md to take this into account
in the speed calculations.
Currently there is no important skipping, but the bitmap-based-resync
that is coming will use this.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 177d2a7..fa608a1 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3241,12 +3241,13 @@
mddev_t *mddev2;
unsigned int currspeed = 0,
window;
- sector_t max_sectors,j;
+ sector_t max_sectors,j, io_sectors;
unsigned long mark[SYNC_MARKS];
sector_t mark_cnt[SYNC_MARKS];
int last_mark,m;
struct list_head *tmp;
sector_t last_check;
+ int skipped = 0;
/* just incase thread restarts... */
if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
@@ -3312,7 +3313,7 @@
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
/* resync follows the size requested by the personality,
- * which default to physical size, but can be virtual size
+ * which defaults to physical size, but can be virtual size
*/
max_sectors = mddev->resync_max_sectors;
else
@@ -3331,9 +3332,10 @@
j = mddev->recovery_cp;
else
j = 0;
+ io_sectors = 0;
for (m = 0; m < SYNC_MARKS; m++) {
mark[m] = jiffies;
- mark_cnt[m] = j;
+ mark_cnt[m] = io_sectors;
}
last_mark = 0;
mddev->resync_mark = mark[last_mark];
@@ -3358,21 +3360,29 @@
}
while (j < max_sectors) {
- int sectors;
+ sector_t sectors;
- sectors = mddev->pers->sync_request(mddev, j, currspeed < sysctl_speed_limit_min);
- if (sectors < 0) {
+ skipped = 0;
+ sectors = mddev->pers->sync_request(mddev, j, &skipped,
+ currspeed < sysctl_speed_limit_min);
+ if (sectors == 0) {
set_bit(MD_RECOVERY_ERR, &mddev->recovery);
goto out;
}
- atomic_add(sectors, &mddev->recovery_active);
+
+ if (!skipped) { /* actual IO requested */
+ io_sectors += sectors;
+ atomic_add(sectors, &mddev->recovery_active);
+ }
+
j += sectors;
if (j>1) mddev->curr_resync = j;
- if (last_check + window > j || j == max_sectors)
+
+ if (last_check + window > io_sectors || j == max_sectors)
continue;
- last_check = j;
+ last_check = io_sectors;
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery) ||
test_bit(MD_RECOVERY_ERR, &mddev->recovery))
@@ -3386,7 +3396,7 @@
mddev->resync_mark = mark[next];
mddev->resync_mark_cnt = mark_cnt[next];
mark[next] = jiffies;
- mark_cnt[next] = j - atomic_read(&mddev->recovery_active);
+ mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
last_mark = next;
}
@@ -3413,7 +3423,8 @@
mddev->queue->unplug_fn(mddev->queue);
cond_resched();
- currspeed = ((unsigned long)(j-mddev->resync_mark_cnt))/2/((jiffies-mddev->resync_mark)/HZ +1) +1;
+ currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
+ /((jiffies-mddev->resync_mark)/HZ +1) +1;
if (currspeed > sysctl_speed_limit_min) {
if ((currspeed > sysctl_speed_limit_max) ||
@@ -3433,7 +3444,7 @@
wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
/* tell personality that we are finished */
- mddev->pers->sync_request(mddev, max_sectors, 1);
+ mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
mddev->curr_resync > 2 &&