[PATCH 001 of 5] md: Remove some old ifdefed-out code from raid5.c

NeilBrown
2006-12-08T01:05:24Z

There are some vestiges of old code that was used for bypassing the
stripe cache on reads in raid5.c. This was never updated after the
change from buffer_heads to bios, but was left as a reminder.

That functionality has nowe been implemented in a completely different
way, so the old code can go.

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
./drivers/md/raid5.c | 63 ---------------------------------------------------
1 file changed, 63 deletions(-)

diff .prev/drivers/md/raid5.c ./drivers/md/raid5.c
--- .prev/drivers/md/raid5.c 2006-12-06 14:23:10.000000000 +1100
+++ ./drivers/md/raid5.c 2006-12-06 14:31:26.000000000 +1100
@@ -544,35 +544,7 @@ static int raid5_end_read_request(struct
}

if (uptodate) {
-#if 0
- struct bio *bio;
- unsigned long flags;
- spin_lock_irqsave(&conf->device_lock, flags);
- /* we can return a buffer if we bypassed the cache or
- * if the top buffer is not in highmem. If there are
- * multiple buffers, leave the extra work to
- * handle_stripe
- */
- buffer = sh->bh_read[i];
- if (buffer &&
- (!PageHighMem(buffer->b_page)
- || buffer->b_page == bh->b_page )
- ) {
- sh->bh_read[i] = buffer->b_reqnext;
- buffer->b_reqnext = NULL;
- } else
- buffer = NULL;
- spin_unlock_irqrestore(&conf->device_lock, flags);
- if (sh->bh_page[i]==bh->b_page)
- set_buffer_uptodate(bh);
- if (buffer) {
- if (buffer->b_page != bh->b_page)
- memcpy(buffer->b_data, bh->b_data, bh->b_size);
- buffer->b_end_io(buffer, 1);
- }
-#else
set_bit(R5_UPTODATE, &sh->dev[i].flags);
-#endif
if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
rdev = conf->disks[i].rdev;
printk(KERN_INFO "raid5:%s: read error corrected (%lu sectors at %llu on %s)\n",
@@ -618,14 +590,6 @@ static int raid5_end_read_request(struct
}
}
rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
-#if 0
- /* must restore b_page before unlocking buffer... */
- if (sh->bh_page[i] != bh->b_page) {
- bh->b_page = sh->bh_page[i];
- bh->b_data = page_address(bh->b_page);
- clear_buffer_uptodate(bh);
- }
-#endif
clear_bit(R5_LOCKED, &sh->dev[i].flags);
set_bit(STRIPE_HANDLE, &sh->state);
release_stripe(sh);
@@ -1619,15 +1583,6 @@ static void handle_stripe5(struct stripe
} else if (test_bit(R5_Insync, &dev->flags)) {
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantread, &dev->flags);
-#if 0
- /* if I am just reading this block and we don't have
- a failed drive, or any pending writes then sidestep the cache */
- if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext &&
- ! syncing && !failed && !to_write) {
- sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page;
- sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data;
- }
-#endif
locked++;
PRINTK("Reading block %d (sync=%d)\n",
i, syncing);
@@ -1645,9 +1600,6 @@ static void handle_stripe5(struct stripe
dev = &sh->dev[i];
if ((dev->towrite || i == sh->pd_idx) &&
(!test_bit(R5_LOCKED, &dev->flags)
-#if 0
-|| sh->bh_page[i]!=bh->b_page
-#endif
) &&
!test_bit(R5_UPTODATE, &dev->flags)) {
if (test_bit(R5_Insync, &dev->flags)
@@ -1659,9 +1611,6 @@ static void handle_stripe5(struct stripe
/* Would I have to read this buffer for reconstruct_write */
if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
(!test_bit(R5_LOCKED, &dev->flags)
-#if 0
-|| sh->bh_page[i] != bh->b_page
-#endif
) &&
!test_bit(R5_UPTODATE, &dev->flags)) {
if (test_bit(R5_Insync, &dev->flags)) rcw++;
@@ -2197,15 +2146,6 @@ static void handle_stripe6(struct stripe
} else if (test_bit(R5_Insync, &dev->flags)) {
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantread, &dev->flags);
-#if 0
- /* if I am just reading this block and we don't have
- a failed drive, or any pending writes then sidestep the cache */
- if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext &&
- ! syncing && !failed && !to_write) {
- sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page;
- sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data;
- }
-#endif
locked++;
PRINTK("Reading block %d (sync=%d)\n",
i, syncing);
@@ -2224,9 +2164,6 @@ static void handle_stripe6(struct stripe
if (!test_bit(R5_OVERWRITE, &dev->flags)
&& i != pd_idx && i != qd_idx
&& (!test_bit(R5_LOCKED, &dev->flags)
-#if 0
- || sh->bh_page[i] != bh->b_page
-#endif
) &&
!test_bit(R5_UPTODATE, &dev->flags)) {
if (test_bit(R5_Insync, &dev->flags)) rcw++;