f2fs: split discard_cmd_list

Split discard_cmd_list to discard_{pend,wait}_list, so while sending/waiting
discard command, we can avoid traversing unneeded entries in original list.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 7b2b402..55a0506 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -210,7 +210,8 @@ struct discard_cmd_control {
        struct task_struct *f2fs_issue_discard; /* discard thread */
        struct list_head discard_entry_list;    /* 4KB discard entry list */
        int nr_discards;                        /* # of discards in the list */
-       struct list_head discard_cmd_list;      /* discard cmd list */
+       struct list_head discard_pend_list;     /* store pending entries */
+       struct list_head discard_wait_list;     /* store on-flushing entries */
        wait_queue_head_t discard_wait_queue;   /* waiting queue for wake-up */
        struct mutex cmd_lock;
        int max_discards;                       /* max. discards to be issued */

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 2bc9014..1a5b3e4 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -677,7 +677,7 @@ static void __add_discard_cmd(struct f2fs_sb_info *sbi,
                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);
+       struct list_head *pend_list = &(dcc->discard_pend_list);
        struct discard_cmd *dc;
 
        dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
@@ -691,7 +691,7 @@ static void __add_discard_cmd(struct f2fs_sb_info *sbi,
        init_completion(&dc->wait);
 
        mutex_lock(&dcc->cmd_lock);
-       list_add_tail(&dc->list, cmd_list);
+       list_add_tail(&dc->list, pend_list);
        mutex_unlock(&dcc->cmd_lock);
 
        atomic_inc(&dcc->discard_cmd_cnt);
@@ -747,6 +747,7 @@ static void __submit_discard_cmd(struct f2fs_sb_info *sbi,
                        bio->bi_end_io = f2fs_submit_discard_endio;
                        bio->bi_opf |= REQ_SYNC;
                        submit_bio(bio);
+                       list_move_tail(&dc->list, &dcc->discard_wait_list);
                }
        } else {
                __remove_discard_cmd(sbi, dc);
@@ -793,31 +794,37 @@ static void __punch_discard_cmd(struct f2fs_sb_info *sbi,
 void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
 {
        struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
-       struct list_head *wait_list = &(dcc->discard_cmd_list);
+       struct list_head *pend_list = &(dcc->discard_pend_list);
+       struct list_head *wait_list = &(dcc->discard_wait_list);
        struct discard_cmd *dc, *tmp;
        struct blk_plug plug;
 
        mutex_lock(&dcc->cmd_lock);
 
-       blk_start_plug(&plug);
-
-       list_for_each_entry_safe(dc, tmp, wait_list, list) {
+       if (blkaddr == NULL_ADDR)
+               goto release_discard;
 
-               if (blkaddr == NULL_ADDR) {
-                       __submit_discard_cmd(sbi, dc);
-                       continue;
-               }
+       list_for_each_entry_safe(dc, tmp, pend_list, list) {
+               if (dc->lstart <= blkaddr && blkaddr < dc->lstart + dc->len)
+                       __punch_discard_cmd(sbi, dc, blkaddr);
+       }
 
+       list_for_each_entry_safe(dc, tmp, wait_list, list) {
                if (dc->lstart <= blkaddr && blkaddr < dc->lstart + dc->len) {
                        if (dc->state == D_SUBMIT)
                                wait_for_completion_io(&dc->wait);
                        __punch_discard_cmd(sbi, dc, blkaddr);
                }
        }
-       blk_finish_plug(&plug);
 
+release_discard:
        /* this comes from f2fs_put_super */
        if (blkaddr == NULL_ADDR) {
+               blk_start_plug(&plug);
+               list_for_each_entry_safe(dc, tmp, pend_list, list)
+                       __submit_discard_cmd(sbi, dc);
+               blk_finish_plug(&plug);
+
                list_for_each_entry_safe(dc, tmp, wait_list, list) {
                        wait_for_completion_io(&dc->wait);
                        __remove_discard_cmd(sbi, dc);
@@ -831,7 +838,8 @@ static int issue_discard_thread(void *data)
        struct f2fs_sb_info *sbi = data;
        struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
        wait_queue_head_t *q = &dcc->discard_wait_queue;
-       struct list_head *cmd_list = &dcc->discard_cmd_list;
+       struct list_head *pend_list = &dcc->discard_pend_list;
+       struct list_head *wait_list = &dcc->discard_wait_list;
        struct discard_cmd *dc, *tmp;
        struct blk_plug plug;
        int iter = 0;
@@ -842,13 +850,17 @@ repeat:
        blk_start_plug(&plug);
 
        mutex_lock(&dcc->cmd_lock);
-       list_for_each_entry_safe(dc, tmp, cmd_list, list) {
+       list_for_each_entry_safe(dc, tmp, pend_list, list) {
+               f2fs_bug_on(sbi, dc->state != D_PREP);
 
                if (is_idle(sbi))
                        __submit_discard_cmd(sbi, dc);
 
-               if (dc->state == D_PREP && iter++ > DISCARD_ISSUE_RATE)
+               if (iter++ > DISCARD_ISSUE_RATE)
                        break;
+       }
+
+       list_for_each_entry_safe(dc, tmp, wait_list, list) {
                if (dc->state == D_DONE)
                        __remove_discard_cmd(sbi, dc);
        }
@@ -859,8 +871,8 @@ repeat:
        iter = 0;
        congestion_wait(BLK_RW_SYNC, HZ/50);
 
-       wait_event_interruptible(*q,
-               kthread_should_stop() || !list_empty(&dcc->discard_cmd_list));
+       wait_event_interruptible(*q, kthread_should_stop() ||
+                       !list_empty(pend_list) || !list_empty(wait_list));
        goto repeat;
 }
 
@@ -1152,7 +1164,8 @@ static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
                return -ENOMEM;
 
        INIT_LIST_HEAD(&dcc->discard_entry_list);
-       INIT_LIST_HEAD(&dcc->discard_cmd_list);
+       INIT_LIST_HEAD(&dcc->discard_pend_list);
+       INIT_LIST_HEAD(&dcc->discard_wait_list);
        mutex_init(&dcc->cmd_lock);
        atomic_set(&dcc->issued_discard, 0);
        atomic_set(&dcc->issing_discard, 0);