Re: [PATCH v2] f2fs: allocate a bio for discarding when actually issuing it

[Jaegeuk Kim]

Change log from v1:
 o change error handling flows

>From 58bb056dfa207a0dc9b9432dcf78758a7784144a Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim 
Date: Tue, 7 Mar 2017 18:02:02 -0800
Subject: [PATCH] f2fs: allocate a bio for discarding when actually issuing it

Let's allocate a bio when issuing discard commands later.

Signed-off-by: Jaegeuk Kim 
---
 fs/f2fs/f2fs.h|   4 +-
 fs/f2fs/segment.c | 136 +-
 2 files changed, 76 insertions(+), 64 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..2d99fb0d44c9 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);
@@ -644,11 +645,12 @@ static void __add_discard_cmd(struct f2fs_sb_info *sbi,
 
dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
INIT_LIST_HEAD(>list);
-   dc->bio = bio;
-   bio->bi_private = dc;
+   dc->bdev = bdev;
dc->lstart = lstart;
+   dc->start = start;
dc->len = len;
dc->state = D_PREP;
+   dc->error = 0;
init_completion(>wait);
 
mutex_lock(>cmd_lock);
@@ -658,22 +660,74 @@ 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(>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(>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 void __submit_discard_cmd(struct f2fs_sb_info *sbi,
+   struct discard_cmd *dc)
+{
+   struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+   struct bio *bio = NULL;
+
+   if (dc->state != D_PREP)
+   return;
+
+   dc->error = __blkdev_issue_discard(dc->bdev,
+   SECTOR_FROM_BLOCK(dc->start),
+   SECTOR_FROM_BLOCK(dc->len),
+   GFP_NOFS, 0, );
+   if (!dc->error) {
+   if (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;
+   atomic_inc(>submit_discard);
+   } else {
+   __remove_discard_cmd(sbi, dc);
+   }
+}
+
+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(_I(sbi)->dcc_info->discard_wait_queue);
+   return 0;
+}
+
 /* This should be covered by global mutex, _i->sentry_lock */
 void 

Re: [PATCH v2] f2fs: allocate a bio for discarding when actually issuing it

[Jaegeuk Kim]

Change log from v1:
 o change error handling flows

>From 58bb056dfa207a0dc9b9432dcf78758a7784144a Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim 
Date: Tue, 7 Mar 2017 18:02:02 -0800
Subject: [PATCH] f2fs: allocate a bio for discarding when actually issuing it

Let's allocate a bio when issuing discard commands later.

Signed-off-by: Jaegeuk Kim 
---
 fs/f2fs/f2fs.h|   4 +-
 fs/f2fs/segment.c | 136 +-
 2 files changed, 76 insertions(+), 64 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..2d99fb0d44c9 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);
@@ -644,11 +645,12 @@ static void __add_discard_cmd(struct f2fs_sb_info *sbi,
 
dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
INIT_LIST_HEAD(>list);
-   dc->bio = bio;
-   bio->bi_private = dc;
+   dc->bdev = bdev;
dc->lstart = lstart;
+   dc->start = start;
dc->len = len;
dc->state = D_PREP;
+   dc->error = 0;
init_completion(>wait);
 
mutex_lock(>cmd_lock);
@@ -658,22 +660,74 @@ 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(>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(>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 void __submit_discard_cmd(struct f2fs_sb_info *sbi,
+   struct discard_cmd *dc)
+{
+   struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+   struct bio *bio = NULL;
+
+   if (dc->state != D_PREP)
+   return;
+
+   dc->error = __blkdev_issue_discard(dc->bdev,
+   SECTOR_FROM_BLOCK(dc->start),
+   SECTOR_FROM_BLOCK(dc->len),
+   GFP_NOFS, 0, );
+   if (!dc->error) {
+   if (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;
+   atomic_inc(>submit_discard);
+   } else {
+   __remove_discard_cmd(sbi, dc);
+   }
+}
+
+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(_I(sbi)->dcc_info->discard_wait_queue);
+   return 0;
+}
+
 /* This should be covered by global mutex, _i->sentry_lock */
 void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t