From 2ca68f5ed7383733102ee53cd8fa4021ecc3b275 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 28 Jul 2011 11:32:10 +1000 Subject: [PATCH] md/raid1: store behind-write pages in bi_vecs. When performing write-behind we allocate pages to store the data during write. Previously we just keep a list of pages. Now we keep a list of bi_vec which includes offset and size. This means that the r1bio has complete information to create a new bio which will be needed for retrying after write errors. Signed-off-by: NeilBrown Reviewed-by: Namhyung Kim --- drivers/md/raid1.c | 33 +++++++++++++++++---------------- drivers/md/raid1.h | 2 +- 2 files changed, 18 insertions(+), 17 deletions(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 141de75a6c7c..b16d2ee5e9dd 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -327,9 +327,9 @@ static void r1_bio_write_done(r1bio_t *r1_bio) /* free extra copy of the data pages */ int i = r1_bio->behind_page_count; while (i--) - safe_put_page(r1_bio->behind_pages[i]); - kfree(r1_bio->behind_pages); - r1_bio->behind_pages = NULL; + safe_put_page(r1_bio->behind_bvecs[i].bv_page); + kfree(r1_bio->behind_bvecs); + r1_bio->behind_bvecs = NULL; } /* clear the bitmap if all writes complete successfully */ bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector, @@ -748,30 +748,31 @@ static void alloc_behind_pages(struct bio *bio, r1bio_t *r1_bio) { int i; struct bio_vec *bvec; - struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page*), + struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec), GFP_NOIO); - if (unlikely(!pages)) + if (unlikely(!bvecs)) return; bio_for_each_segment(bvec, bio, i) { - pages[i] = alloc_page(GFP_NOIO); - if (unlikely(!pages[i])) + bvecs[i] = *bvec; + bvecs[i].bv_page = alloc_page(GFP_NOIO); + if (unlikely(!bvecs[i].bv_page)) goto do_sync_io; - memcpy(kmap(pages[i]) + bvec->bv_offset, - kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len); - kunmap(pages[i]); + memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset, + kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len); + kunmap(bvecs[i].bv_page); kunmap(bvec->bv_page); } - r1_bio->behind_pages = pages; + r1_bio->behind_bvecs = bvecs; r1_bio->behind_page_count = bio->bi_vcnt; set_bit(R1BIO_BehindIO, &r1_bio->state); return; do_sync_io: for (i = 0; i < bio->bi_vcnt; i++) - if (pages[i]) - put_page(pages[i]); - kfree(pages); + if (bvecs[i].bv_page) + put_page(bvecs[i].bv_page); + kfree(bvecs); PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size); } @@ -1058,7 +1059,7 @@ read_again: &r1_bio->state)); first_clone = 0; } - if (r1_bio->behind_pages) { + if (r1_bio->behind_bvecs) { struct bio_vec *bvec; int j; @@ -1070,7 +1071,7 @@ read_again: * them all */ __bio_for_each_segment(bvec, mbio, j, 0) - bvec->bv_page = r1_bio->behind_pages[j]; + bvec->bv_page = r1_bio->behind_bvecs[j].bv_page; if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags)) atomic_inc(&r1_bio->behind_remaining); } diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h index f81360d49af4..b7885474e96c 100644 --- a/drivers/md/raid1.h +++ b/drivers/md/raid1.h @@ -101,7 +101,7 @@ struct r1bio_s { struct list_head retry_list; /* Next two are only valid when R1BIO_BehindIO is set */ - struct page **behind_pages; + struct bio_vec *behind_bvecs; int behind_page_count; /* * if the IO is in WRITE direction, then multiple bios are used. -- 2.30.2