[Devel] [PATCH RHEL8 COMMIT] ploop: Always defer bios for work
Konstantin Khorenko
khorenko at virtuozzo.com
Mon May 17 19:04:37 MSK 2021
The commit is pushed to "branch-rh8-4.18.0-240.1.1.vz8.5.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-240.1.1.vz8.5.30
------>
commit 8e22feaf12b11d34a1f6ee8a0f69f2ded748596d
Author: Kirill Tkhai <ktkhai at virtuozzo.com>
Date: Mon May 17 19:04:37 2021 +0300
ploop: Always defer bios for work
This is preparations for killing loop. Since there won't be loop,
we always need work to submit IO.
Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
=====================
Patchset description:
dm-ploop: Kill loop
Intermediate patches can't be base for bisect.
In scope of https://jira.sw.ru/browse/PSBM-123654
Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
drivers/md/dm-ploop-cmd.c | 13 ++-------
drivers/md/dm-ploop-map.c | 67 ++++++++---------------------------------------
drivers/md/dm-ploop.h | 19 --------------
3 files changed, 13 insertions(+), 86 deletions(-)
diff --git a/drivers/md/dm-ploop-cmd.c b/drivers/md/dm-ploop-cmd.c
index 139dffca1ce5..346f69056a11 100644
--- a/drivers/md/dm-ploop-cmd.c
+++ b/drivers/md/dm-ploop-cmd.c
@@ -231,7 +231,7 @@ static int ploop_grow_relocate_cluster(struct ploop *ploop,
{
struct bio *bio = cmd->resize.bio;
unsigned int new_dst, cluster, dst_cluster;
- bool is_locked, defer_bio_count = false;
+ bool is_locked;
int ret = 0;
dst_cluster = cmd->resize.dst_cluster;
@@ -254,9 +254,7 @@ static int ploop_grow_relocate_cluster(struct ploop *ploop,
goto not_occupied;
}
- /* Redirect bios to kwork and wait inflights, which may use @cluster */
- force_defer_bio_count_inc(ploop);
- defer_bio_count = true;
+ /* Wait inflights, which may use @cluster */
ret = ploop_inflight_bios_ref_switch(ploop, true);
if (ret < 0)
goto out;
@@ -300,9 +298,6 @@ static int ploop_grow_relocate_cluster(struct ploop *ploop,
/* Zero new BAT entries on disk. */
ret = ploop_write_zero_cluster_sync(ploop, bio, dst_cluster);
out:
- if (defer_bio_count)
- force_defer_bio_count_dec(ploop);
-
return ret;
}
@@ -712,7 +707,6 @@ static void process_notify_delta_merged(struct ploop *ploop,
struct file *file;
int ret;
- force_defer_bio_count_inc(ploop);
ret = ploop_inflight_bios_ref_switch(ploop, true);
if (ret) {
cmd->retval = ret;
@@ -761,7 +755,6 @@ static void process_notify_delta_merged(struct ploop *ploop,
fput(file);
cmd->retval = 0;
out:
- force_defer_bio_count_dec(ploop);
complete(&cmd->comp); /* Last touch of cmd memory */
}
@@ -773,7 +766,6 @@ static void process_update_delta_index(struct ploop *ploop,
unsigned int cluster, dst_cluster, n;
int ret;
- force_defer_bio_count_inc(ploop);
ret = ploop_inflight_bios_ref_switch(ploop, true);
if (ret)
goto out;
@@ -801,7 +793,6 @@ static void process_update_delta_index(struct ploop *ploop,
unlock:
write_unlock_irq(&ploop->bat_rwlock);
out:
- force_defer_bio_count_dec(ploop);
cmd->retval = ret;
complete(&cmd->comp); /* Last touch of cmd memory */
}
diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index 0b902a67f5de..dd209f2a0a8c 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -440,22 +440,18 @@ static void handle_discard_bio(struct ploop *ploop, struct bio *bio,
if (!ploop->force_link_inflight_bios) {
/*
- * Switch ploop to mode, when requests are handled
- * from kwork only, and force all not exclusive
- * inflight bios to link into inflight_bios_rbtree.
- * Note, that this does not wait completion of
- * two-stages requests (currently, these may be only
- * cow, which take cluster lk, so we are safe with
- * them).
+ * Force all not exclusive inflight bios to link into
+ * inflight_bios_rbtree. Note, that this does not wait
+ * completion of two-stages requests (currently, these
+ * may be only cow, which take cluster lk, so we are
+ * safe with them).
*/
ploop->force_link_inflight_bios = true;
- force_defer_bio_count_inc(ploop);
ret = ploop_inflight_bios_ref_switch(ploop, true);
if (ret) {
pr_err_ratelimited("ploop: discard ignored by err=%d\n",
ret);
ploop->force_link_inflight_bios = false;
- force_defer_bio_count_dec(ploop);
goto enotsupp;
}
}
@@ -1456,10 +1452,8 @@ static void do_discard_cleanup(struct ploop *ploop)
smp_rmb();
cleanup_jiffies = READ_ONCE(ploop->pending_discard_cleanup);
- if (time_after(jiffies, cleanup_jiffies + CLEANUP_DELAY * HZ)) {
+ if (time_after(jiffies, cleanup_jiffies + CLEANUP_DELAY * HZ))
ploop->force_link_inflight_bios = false;
- force_defer_bio_count_dec(ploop);
- }
}
}
@@ -1596,20 +1590,6 @@ void do_ploop_work(struct work_struct *ws)
check_services_timeout(ploop);
}
-static bool should_defer_bio(struct ploop *ploop, struct bio *bio,
- unsigned int cluster)
-{
- struct push_backup *pb = ploop->pb;
-
- lockdep_assert_held(&ploop->bat_rwlock);
-
- if (ploop->force_defer_bio_count)
- return true;
- if (pb && pb->alive && op_is_write(bio->bi_opf))
- return test_bit(cluster, pb->ppb_map);
- return false;
-}
-
/*
* ploop_map() tries to map bio to origins or delays it.
* It never modifies ploop->bat_entries and other cached
@@ -1618,43 +1598,18 @@ static bool should_defer_bio(struct ploop *ploop, struct bio *bio,
int ploop_map(struct dm_target *ti, struct bio *bio)
{
struct ploop *ploop = ti->private;
- unsigned int cluster, dst_cluster;
- unsigned long flags;
- bool in_top_delta;
+ unsigned int cluster;
ploop_init_end_io(ploop, bio);
if (bio_sectors(bio)) {
- if (op_is_discard(bio->bi_opf))
- return ploop_map_discard(ploop, bio);
if (ploop_bio_cluster(ploop, bio, &cluster) < 0)
return DM_MAPIO_KILL;
+ if (op_is_discard(bio->bi_opf))
+ return ploop_map_discard(ploop, bio);
- /* map it */
- read_lock_irqsave(&ploop->bat_rwlock, flags);
- dst_cluster = ploop_bat_entries(ploop, cluster, NULL);
- in_top_delta = cluster_is_in_top_delta(ploop, cluster);
- if (unlikely(should_defer_bio(ploop, bio, cluster))) {
- /* defer all bios */
- in_top_delta = false;
- dst_cluster = 0;
- }
- if (in_top_delta)
- inc_nr_inflight(ploop, bio);
- read_unlock_irqrestore(&ploop->bat_rwlock, flags);
-
- if (!in_top_delta) {
- if (op_is_write(bio->bi_opf) || dst_cluster != BAT_ENTRY_NONE) {
- defer_bios(ploop, bio, NULL);
- } else {
- zero_fill_bio(bio);
- bio_endio(bio);
- }
-
- return DM_MAPIO_SUBMITTED;
- }
-
- remap_to_cluster(ploop, bio, dst_cluster);
+ defer_bios(ploop, bio, NULL);
+ return DM_MAPIO_SUBMITTED;
}
remap_to_origin(ploop, bio);
diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
index 93a902d66acf..0eb313d4c412 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -175,7 +175,6 @@ struct ploop {
unsigned int tb_nr; /* tracking_bitmap size in bits */
unsigned int tb_cursor;
- int force_defer_bio_count; /* Protected by bat_rwlock */
bool force_link_inflight_bios;
/*
* Hash table to link non-exclusive submitted bios.
@@ -446,24 +445,6 @@ static inline void init_bat_entries_iter(struct ploop *ploop, unsigned int page_
*end = ((ploop->nr_bat_entries + PLOOP_MAP_OFFSET) % count) - 1;
}
-static inline void force_defer_bio_count_inc(struct ploop *ploop)
-{
- unsigned long flags;
-
- write_lock_irqsave(&ploop->bat_rwlock, flags);
- WARN_ON_ONCE(ploop->force_defer_bio_count++ < 0);
- write_unlock_irqrestore(&ploop->bat_rwlock, flags);
-}
-
-static inline void force_defer_bio_count_dec(struct ploop *ploop)
-{
- unsigned long flags;
-
- write_lock_irqsave(&ploop->bat_rwlock, flags);
- WARN_ON_ONCE(--ploop->force_defer_bio_count < 0);
- write_unlock_irqrestore(&ploop->bat_rwlock, flags);
-}
-
extern void __track_bio(struct ploop *ploop, struct bio *bio);
static inline void track_bio(struct ploop *ploop, struct bio *bio)
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