On Tue, Feb 28, 2017 at 11:41:41PM +0800, Ming Lei wrote:
> Now we allocate one page array for managing resync pages, instead
> of using bio's vec table to do that, and the old way is very hacky
> and won't work any more if multipage bvec is enabled.
>
> The introduced cost is that we need to allocate (128 + 16) * copies
> bytes per r10_bio, and it is fine because the inflight r10_bio for
> resync shouldn't be much, as pointed by Shaohua.
>
> Also bio_reset() in raid10_sync_request() and reshape_request()
> are removed because all bios are freshly new now in these functions
> and not necessary to reset any more.
>
> This patch can be thought as cleanup too.
>
> Suggested-by: Shaohua Li <shli@xxxxxxxxxx>
> Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
> ---
> drivers/md/raid10.c | 125 ++++++++++++++++++++++++++++++----------------------
> 1 file changed, 73 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> index a9ddd4f14008..f887b21332e7 100644
> --- a/drivers/md/raid10.c
> +++ b/drivers/md/raid10.c
> @@ -110,6 +110,16 @@ static void end_reshape(struct r10conf *conf);
> #define raid10_log(md, fmt, args...) \
> do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid10 " fmt, ##args); } while (0)
>
> +static inline struct resync_pages *get_resync_pages(struct bio *bio)
> +{
> + return bio->bi_private;
> +}
> +
> +static inline struct r10bio *get_resync_r10bio(struct bio *bio)
> +{
> + return get_resync_pages(bio)->raid_bio;
> +}
Same applies to raid10 too. embedded the resync_pages into r10bio, possibly a
pointer. Merge the 11, 12, 13 into a single patch.
Thanks,
Shaohua
> +
> static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
> {
> struct r10conf *conf = data;
> @@ -140,11 +150,11 @@ static void r10bio_pool_free(void *r10_bio, void *data)
> static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
> {
> struct r10conf *conf = data;
> - struct page *page;
> struct r10bio *r10_bio;
> struct bio *bio;
> - int i, j;
> - int nalloc;
> + int j;
> + int nalloc, nalloc_rp;
> + struct resync_pages *rps;
>
> r10_bio = r10bio_pool_alloc(gfp_flags, conf);
> if (!r10_bio)
> @@ -156,6 +166,15 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
> else
> nalloc = 2; /* recovery */
>
> + /* allocate once for all bios */
> + if (!conf->have_replacement)
> + nalloc_rp = nalloc;
> + else
> + nalloc_rp = nalloc * 2;
> + rps = kmalloc(sizeof(struct resync_pages) * nalloc_rp, gfp_flags);
> + if (!rps)
> + goto out_free_r10bio;
> +
> /*
> * Allocate bios.
> */
> @@ -175,36 +194,40 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
> * Allocate RESYNC_PAGES data pages and attach them
> * where needed.
> */
> - for (j = 0 ; j < nalloc; j++) {
> + for (j = 0; j < nalloc; j++) {
> struct bio *rbio = r10_bio->devs[j].repl_bio;
> + struct resync_pages *rp, *rp_repl;
> +
> + rp = &rps[j];
> + if (rbio)
> + rp_repl = &rps[nalloc + j];
> +
> bio = r10_bio->devs[j].bio;
> - for (i = 0; i < RESYNC_PAGES; i++) {
> - if (j > 0 && !test_bit(MD_RECOVERY_SYNC,
> - &conf->mddev->recovery)) {
> - /* we can share bv_page's during recovery
> - * and reshape */
> - struct bio *rbio = r10_bio->devs[0].bio;
> - page = rbio->bi_io_vec[i].bv_page;
> - get_page(page);
> - } else
> - page = alloc_page(gfp_flags);
> - if (unlikely(!page))
> +
> + if (!j || test_bit(MD_RECOVERY_SYNC,
> + &conf->mddev->recovery)) {
> + if (resync_alloc_pages(rp, gfp_flags))
> goto out_free_pages;
> + } else {
> + memcpy(rp, &rps[0], sizeof(*rp));
> + resync_get_all_pages(rp);
> + }
>
> - bio->bi_io_vec[i].bv_page = page;
> - if (rbio)
> - rbio->bi_io_vec[i].bv_page = page;
> + rp->idx = 0;
> + rp->raid_bio = r10_bio;
> + bio->bi_private = rp;
> + if (rbio) {
> + memcpy(rp_repl, rp, sizeof(*rp));
> + rbio->bi_private = rp_repl;
> }
> }
>
> return r10_bio;
>
> out_free_pages:
> - for ( ; i > 0 ; i--)
> - safe_put_page(bio->bi_io_vec[i-1].bv_page);
> - while (j--)
> - for (i = 0; i < RESYNC_PAGES ; i++)
> - safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
> + while (--j >= 0)
> + resync_free_pages(&rps[j * 2]);
> +
> j = 0;
> out_free_bio:
> for ( ; j < nalloc; j++) {
> @@ -213,30 +236,34 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
> if (r10_bio->devs[j].repl_bio)
> bio_put(r10_bio->devs[j].repl_bio);
> }
> + kfree(rps);
> +out_free_r10bio:
> r10bio_pool_free(r10_bio, conf);
> return NULL;
> }
>
> static void r10buf_pool_free(void *__r10_bio, void *data)
> {
> - int i;
> struct r10conf *conf = data;
> struct r10bio *r10bio = __r10_bio;
> int j;
> + struct resync_pages *rp = NULL;
>
> - for (j=0; j < conf->copies; j++) {
> + for (j = conf->copies; j--; ) {
> struct bio *bio = r10bio->devs[j].bio;
> - if (bio) {
> - for (i = 0; i < RESYNC_PAGES; i++) {
> - safe_put_page(bio->bi_io_vec[i].bv_page);
> - bio->bi_io_vec[i].bv_page = NULL;
> - }
> - bio_put(bio);
> - }
> +
> + rp = get_resync_pages(bio);
> + resync_free_pages(rp);
> + bio_put(bio);
> +
> bio = r10bio->devs[j].repl_bio;
> if (bio)
> bio_put(bio);
> }
> +
> + /* resync pages array stored in the 1st bio's .bi_private */
> + kfree(rp);
> +
> r10bio_pool_free(r10bio, conf);
> }
>
> @@ -1935,7 +1962,7 @@ static void __end_sync_read(struct r10bio *r10_bio, struct bio *bio, int d)
>
> static void end_sync_read(struct bio *bio)
> {
> - struct r10bio *r10_bio = bio->bi_private;
> + struct r10bio *r10_bio = get_resync_r10bio(bio);
> struct r10conf *conf = r10_bio->mddev->private;
> int d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
>
> @@ -1944,6 +1971,7 @@ static void end_sync_read(struct bio *bio)
>
> static void end_reshape_read(struct bio *bio)
> {
> + /* reshape read bio isn't allocated from r10buf_pool */
> struct r10bio *r10_bio = bio->bi_private;
>
> __end_sync_read(r10_bio, bio, r10_bio->read_slot);
> @@ -1978,7 +2006,7 @@ static void end_sync_request(struct r10bio *r10_bio)
>
> static void end_sync_write(struct bio *bio)
> {
> - struct r10bio *r10_bio = bio->bi_private;
> + struct r10bio *r10_bio = get_resync_r10bio(bio);
> struct mddev *mddev = r10_bio->mddev;
> struct r10conf *conf = mddev->private;
> int d;
> @@ -2058,6 +2086,7 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
> for (i=0 ; i < conf->copies ; i++) {
> int j, d;
> struct md_rdev *rdev;
> + struct resync_pages *rp;
>
> tbio = r10_bio->devs[i].bio;
>
> @@ -2099,11 +2128,13 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
> * First we need to fixup bv_offset, bv_len and
> * bi_vecs, as the read request might have corrupted these
> */
> + rp = get_resync_pages(tbio);
> bio_reset(tbio);
>
> tbio->bi_vcnt = vcnt;
> tbio->bi_iter.bi_size = fbio->bi_iter.bi_size;
> - tbio->bi_private = r10_bio;
> + rp->raid_bio = r10_bio;
> + tbio->bi_private = rp;
> tbio->bi_iter.bi_sector = r10_bio->devs[i].addr;
> tbio->bi_end_io = end_sync_write;
> bio_set_op_attrs(tbio, REQ_OP_WRITE, 0);
> @@ -3171,10 +3202,8 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> }
> }
> bio = r10_bio->devs[0].bio;
> - bio_reset(bio);
> bio->bi_next = biolist;
> biolist = bio;
> - bio->bi_private = r10_bio;
> bio->bi_end_io = end_sync_read;
> bio_set_op_attrs(bio, REQ_OP_READ, 0);
> if (test_bit(FailFast, &rdev->flags))
> @@ -3198,10 +3227,8 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
>
> if (!test_bit(In_sync, &mrdev->flags)) {
> bio = r10_bio->devs[1].bio;
> - bio_reset(bio);
> bio->bi_next = biolist;
> biolist = bio;
> - bio->bi_private = r10_bio;
> bio->bi_end_io = end_sync_write;
> bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
> bio->bi_iter.bi_sector = to_addr
> @@ -3226,10 +3253,8 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> if (mreplace == NULL || bio == NULL ||
> test_bit(Faulty, &mreplace->flags))
> break;
> - bio_reset(bio);
> bio->bi_next = biolist;
> biolist = bio;
> - bio->bi_private = r10_bio;
> bio->bi_end_io = end_sync_write;
> bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
> bio->bi_iter.bi_sector = to_addr +
> @@ -3351,7 +3376,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> r10_bio->devs[i].repl_bio->bi_end_io = NULL;
>
> bio = r10_bio->devs[i].bio;
> - bio_reset(bio);
> bio->bi_error = -EIO;
> rcu_read_lock();
> rdev = rcu_dereference(conf->mirrors[d].rdev);
> @@ -3376,7 +3400,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> atomic_inc(&r10_bio->remaining);
> bio->bi_next = biolist;
> biolist = bio;
> - bio->bi_private = r10_bio;
> bio->bi_end_io = end_sync_read;
> bio_set_op_attrs(bio, REQ_OP_READ, 0);
> if (test_bit(FailFast, &conf->mirrors[d].rdev->flags))
> @@ -3395,13 +3418,11 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
>
> /* Need to set up for writing to the replacement */
> bio = r10_bio->devs[i].repl_bio;
> - bio_reset(bio);
> bio->bi_error = -EIO;
>
> sector = r10_bio->devs[i].addr;
> bio->bi_next = biolist;
> biolist = bio;
> - bio->bi_private = r10_bio;
> bio->bi_end_io = end_sync_write;
> bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
> if (test_bit(FailFast, &conf->mirrors[d].rdev->flags))
> @@ -3440,7 +3461,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> if (len == 0)
> break;
> for (bio= biolist ; bio ; bio=bio->bi_next) {
> - page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
> + page = resync_fetch_page(get_resync_pages(bio));
> /*
> * won't fail because the vec table is big enough
> * to hold all these pages
> @@ -3449,7 +3470,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> }
> nr_sectors += len>>9;
> sector_nr += len>>9;
> - } while (biolist->bi_vcnt < RESYNC_PAGES);
> + } while (resync_page_available(get_resync_pages(biolist)));
> r10_bio->sectors = nr_sectors;
>
> while (biolist) {
> @@ -3457,7 +3478,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> biolist = biolist->bi_next;
>
> bio->bi_next = NULL;
> - r10_bio = bio->bi_private;
> + r10_bio = get_resync_r10bio(bio);
> r10_bio->sectors = nr_sectors;
>
> if (bio->bi_end_io == end_sync_read) {
> @@ -4352,6 +4373,7 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
> struct bio *blist;
> struct bio *bio, *read_bio;
> int sectors_done = 0;
> + struct page **pages;
>
> if (sector_nr == 0) {
> /* If restarting in the middle, skip the initial sectors */
> @@ -4502,11 +4524,9 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
> if (!rdev2 || test_bit(Faulty, &rdev2->flags))
> continue;
>
> - bio_reset(b);
> b->bi_bdev = rdev2->bdev;
> b->bi_iter.bi_sector = r10_bio->devs[s/2].addr +
> rdev2->new_data_offset;
> - b->bi_private = r10_bio;
> b->bi_end_io = end_reshape_write;
> bio_set_op_attrs(b, REQ_OP_WRITE, 0);
> b->bi_next = blist;
> @@ -4516,8 +4536,9 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
> /* Now add as many pages as possible to all of these bios. */
>
> nr_sectors = 0;
> + pages = get_resync_pages(r10_bio->devs[0].bio)->pages;
> for (s = 0 ; s < max_sectors; s += PAGE_SIZE >> 9) {
> - struct page *page = r10_bio->devs[0].bio->bi_io_vec[s/(PAGE_SIZE>>9)].bv_page;
> + struct page *page = pages[s / (PAGE_SIZE >> 9)];
> int len = (max_sectors - s) << 9;
> if (len > PAGE_SIZE)
> len = PAGE_SIZE;
> @@ -4701,7 +4722,7 @@ static int handle_reshape_read_error(struct mddev *mddev,
>
> static void end_reshape_write(struct bio *bio)
> {
> - struct r10bio *r10_bio = bio->bi_private;
> + struct r10bio *r10_bio = get_resync_r10bio(bio);
> struct mddev *mddev = r10_bio->mddev;
> struct r10conf *conf = mddev->private;
> int d;
> --
> 2.7.4
>
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