On Tue, Mar 07, 2017 at 06:33:33PM -0800, Jaegeuk Kim wrote:
> Let's allocate a bio when issuing discard commands later.
Does this solve the issue with your queue stalls?
>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
> fs/f2fs/f2fs.h | 4 +-
> fs/f2fs/segment.c | 113 ++++++++++++++++++++++++++++--------------------------
> 2 files changed, 62 insertions(+), 55 deletions(-)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index a58c2e43bd2a..870bb4d9bc65 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -197,10 +197,12 @@ enum {
> struct discard_cmd {
> struct list_head list; /* command list */
> struct completion wait; /* compleation */
> + struct block_device *bdev; /* bdev */
> block_t lstart; /* logical start address */
> + block_t start; /* actual start address in dev */
> block_t len; /* length */
> - struct bio *bio; /* bio */
> int state; /* state */
> + int error; /* bio error */
> };
>
> struct discard_cmd_control {
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 50c65cc4645a..d8f9e6c895cd 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -636,7 +636,8 @@ static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
> }
>
> static void __add_discard_cmd(struct f2fs_sb_info *sbi,
> - struct bio *bio, block_t lstart, block_t len)
> + struct block_device *bdev, block_t lstart,
> + block_t start, block_t len)
> {
> struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
> struct list_head *cmd_list = &(dcc->discard_cmd_list);
> @@ -644,9 +645,9 @@ static void __add_discard_cmd(struct f2fs_sb_info *sbi,
>
> dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
> INIT_LIST_HEAD(&dc->list);
> - dc->bio = bio;
> - bio->bi_private = dc;
> + dc->bdev = bdev;
> dc->lstart = lstart;
> + dc->start = start;
> dc->len = len;
> dc->state = D_PREP;
> init_completion(&dc->wait);
> @@ -658,22 +659,66 @@ static void __add_discard_cmd(struct f2fs_sb_info *sbi,
>
> static void __remove_discard_cmd(struct f2fs_sb_info *sbi, struct discard_cmd *dc)
> {
> - int err = dc->bio->bi_error;
> -
> if (dc->state == D_DONE)
> atomic_dec(&(SM_I(sbi)->dcc_info->submit_discard));
>
> - if (err == -EOPNOTSUPP)
> - err = 0;
> + if (dc->error == -EOPNOTSUPP)
> + dc->error = 0;
>
> - if (err)
> + if (dc->error)
> f2fs_msg(sbi->sb, KERN_INFO,
> - "Issue discard failed, ret: %d", err);
> - bio_put(dc->bio);
> + "Issue discard failed, ret: %d", dc->error);
> list_del(&dc->list);
> kmem_cache_free(discard_cmd_slab, dc);
> }
>
> +static void f2fs_submit_discard_endio(struct bio *bio)
> +{
> + struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
> +
> + complete(&dc->wait);
> + dc->error = bio->bi_error;
> + dc->state = D_DONE;
> + bio_put(bio);
> +}
> +
> +/* this function is copied from blkdev_issue_discard from block/blk-lib.c */
> +static int __submit_discard_cmd(struct discard_cmd *dc)
> +{
> + struct bio *bio = NULL;
> + int err;
> +
> + err = __blkdev_issue_discard(dc->bdev,
> + SECTOR_FROM_BLOCK(dc->start),
> + SECTOR_FROM_BLOCK(dc->len),
> + GFP_NOFS, 0, &bio);
> + if (!err && bio) {
> + bio->bi_private = dc;
> + bio->bi_end_io = f2fs_submit_discard_endio;
> + bio->bi_opf |= REQ_SYNC;
> + submit_bio(bio);
> + }
> + dc->state = D_SUBMIT;
> + return err;
> +}
> +
> +static int __queue_discard_cmd(struct f2fs_sb_info *sbi,
> + struct block_device *bdev, block_t blkstart, block_t blklen)
> +{
> + block_t lblkstart = blkstart;
> +
> + trace_f2fs_issue_discard(bdev, blkstart, blklen);
> +
> + if (sbi->s_ndevs) {
> + int devi = f2fs_target_device_index(sbi, blkstart);
> +
> + blkstart -= FDEV(devi).start_blk;
> + }
> + __add_discard_cmd(sbi, bdev, lblkstart, blkstart, blklen);
> + wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue);
> + return 0;
> +}
> +
> /* This should be covered by global mutex, &sit_i->sentry_lock */
> void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
> {
> @@ -690,8 +735,7 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
>
> if (blkaddr == NULL_ADDR) {
> if (dc->state == D_PREP) {
> - dc->state = D_SUBMIT;
> - submit_bio(dc->bio);
> + __submit_discard_cmd(dc);
> atomic_inc(&dcc->submit_discard);
> }
> continue;
> @@ -716,14 +760,6 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
> mutex_unlock(&dcc->cmd_lock);
> }
>
> -static void f2fs_submit_discard_endio(struct bio *bio)
> -{
> - struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
> -
> - complete(&dc->wait);
> - dc->state = D_DONE;
> -}
> -
> static int issue_discard_thread(void *data)
> {
> struct f2fs_sb_info *sbi = data;
> @@ -742,8 +778,7 @@ static int issue_discard_thread(void *data)
> mutex_lock(&dcc->cmd_lock);
> list_for_each_entry_safe(dc, tmp, cmd_list, list) {
> if (dc->state == D_PREP) {
> - dc->state = D_SUBMIT;
> - submit_bio(dc->bio);
> + __submit_discard_cmd(dc);
> atomic_inc(&dcc->submit_discard);
> if (iter++ > DISCARD_ISSUE_RATE)
> break;
> @@ -763,36 +798,6 @@ static int issue_discard_thread(void *data)
> goto repeat;
> }
>
> -
> -/* this function is copied from blkdev_issue_discard from block/blk-lib.c */
> -static int __f2fs_issue_discard_async(struct f2fs_sb_info *sbi,
> - struct block_device *bdev, block_t blkstart, block_t blklen)
> -{
> - struct bio *bio = NULL;
> - block_t lblkstart = blkstart;
> - int err;
> -
> - trace_f2fs_issue_discard(bdev, blkstart, blklen);
> -
> - if (sbi->s_ndevs) {
> - int devi = f2fs_target_device_index(sbi, blkstart);
> -
> - blkstart -= FDEV(devi).start_blk;
> - }
> - err = __blkdev_issue_discard(bdev,
> - SECTOR_FROM_BLOCK(blkstart),
> - SECTOR_FROM_BLOCK(blklen),
> - GFP_NOFS, 0, &bio);
> - if (!err && bio) {
> - bio->bi_end_io = f2fs_submit_discard_endio;
> - bio->bi_opf |= REQ_SYNC;
> -
> - __add_discard_cmd(sbi, bio, lblkstart, blklen);
> - wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue);
> - }
> - return err;
> -}
> -
> #ifdef CONFIG_BLK_DEV_ZONED
> static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
> struct block_device *bdev, block_t blkstart, block_t blklen)
> @@ -816,7 +821,7 @@ static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
> case BLK_ZONE_TYPE_CONVENTIONAL:
> if (!blk_queue_discard(bdev_get_queue(bdev)))
> return 0;
> - return __f2fs_issue_discard_async(sbi, bdev, lblkstart, blklen);
> + return __queue_discard_cmd(sbi, bdev, lblkstart, blklen);
> case BLK_ZONE_TYPE_SEQWRITE_REQ:
> case BLK_ZONE_TYPE_SEQWRITE_PREF:
> sector = SECTOR_FROM_BLOCK(blkstart);
> @@ -848,7 +853,7 @@ static int __issue_discard_async(struct f2fs_sb_info *sbi,
> bdev_zoned_model(bdev) != BLK_ZONED_NONE)
> return __f2fs_issue_discard_zone(sbi, bdev, blkstart, blklen);
> #endif
> - return __f2fs_issue_discard_async(sbi, bdev, blkstart, blklen);
> + return __queue_discard_cmd(sbi, bdev, blkstart, blklen);
> }
>
> static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
> --
> 2.11.0
>
---end quoted text---
