[Devel] [PATCH rh7] ploop: io_direct: delay f_op->fsync() until index_update for reloc requests
Maxim Patlasov
mpatlasov at virtuozzo.com
Tue Jul 5 16:13:52 PDT 2016
Commit 9f860e606 introduced an engine to delay fsync: doing
fallocate(FALLOC_FL_CONVERT_UNWRITTEN) dio_post_submit marks
io as PLOOP_IO_FSYNC_DELAYED to ensure that fsync happens
later, when incoming FLUSH|FUA comes.
That was deemed as important because (PSBM-47026):
> This optimization becomes more important due to the fact that customers tend to use pcompact heavily => ploop images grow each day.
Now, we can easily re-use the engine to delay fsync for reloc
requests as well. As explained in the description of commit
5aa3fe09:
> 1->read_data_from_old_post
> 2->write_to_new_pos
> ->sumbit_alloc
> ->submit_pad
> ->post_submit->convert_unwritten
> 3->update_index ->write_page with FLUSH|FUA
> 4->nullify_old_pos
> 5->issue_flush
by the time of step 3 extent coversion is not yet stable because
belongs to uncommitted transaction. But instead of doing fsync
inside ->post_submit, we can fsync later, as the very first step
of write_page for index_update.
https://jira.sw.ru/browse/PSBM-47026
Signed-off-by: Maxim Patlasov <mpatlasov at virtuozzo.com>
---
drivers/block/ploop/dev.c | 4 ++--
drivers/block/ploop/io_direct.c | 25 ++++++++++++++++++++++++-
drivers/block/ploop/io_kaio.c | 3 ++-
drivers/block/ploop/map.c | 17 ++++++++++++-----
include/linux/ploop/ploop.h | 3 ++-
5 files changed, 42 insertions(+), 10 deletions(-)
diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
index e5f010b..40768b6 100644
--- a/drivers/block/ploop/dev.c
+++ b/drivers/block/ploop/dev.c
@@ -4097,7 +4097,7 @@ static void ploop_relocate(struct ploop_device * plo)
preq->bl.tail = preq->bl.head = NULL;
preq->req_cluster = 0;
preq->req_size = 0;
- preq->req_rw = WRITE_SYNC|REQ_FUA;
+ preq->req_rw = WRITE_SYNC;
preq->eng_state = PLOOP_E_ENTRY;
preq->state = (1 << PLOOP_REQ_SYNC) | (1 << PLOOP_REQ_RELOC_A);
preq->error = 0;
@@ -4401,7 +4401,7 @@ static void ploop_relocblks_process(struct ploop_device *plo)
preq->bl.tail = preq->bl.head = NULL;
preq->req_cluster = ~0U; /* uninitialized */
preq->req_size = 0;
- preq->req_rw = WRITE_SYNC|REQ_FUA;
+ preq->req_rw = WRITE_SYNC;
preq->eng_state = PLOOP_E_ENTRY;
preq->state = (1 << PLOOP_REQ_SYNC) | (1 << PLOOP_REQ_RELOC_S);
preq->error = 0;
diff --git a/drivers/block/ploop/io_direct.c b/drivers/block/ploop/io_direct.c
index 1086850..0a5fb15 100644
--- a/drivers/block/ploop/io_direct.c
+++ b/drivers/block/ploop/io_direct.c
@@ -1494,13 +1494,36 @@ dio_read_page(struct ploop_io * io, struct ploop_request * preq,
static void
dio_write_page(struct ploop_io * io, struct ploop_request * preq,
- struct page * page, sector_t sec, unsigned long rw)
+ struct page * page, sector_t sec, unsigned long rw,
+ int do_fsync_if_delayed)
{
if (!(io->files.file->f_mode & FMODE_WRITE)) {
PLOOP_FAIL_REQUEST(preq, -EBADF);
return;
}
+ if (do_fsync_if_delayed &&
+ test_bit(PLOOP_IO_FSYNC_DELAYED, &io->io_state)) {
+ struct ploop_device * plo = io->plo;
+ u64 io_count;
+ int err;
+
+ spin_lock_irq(&plo->lock);
+ io_count = io->io_count;
+ spin_unlock_irq(&plo->lock);
+
+ err = io->ops->sync(io);
+ if (err) {
+ PLOOP_FAIL_REQUEST(preq, -EBADF);
+ return;
+ }
+
+ spin_lock_irq(&plo->lock);
+ if (io_count == io->io_count && !(io_count & 1))
+ clear_bit(PLOOP_IO_FSYNC_DELAYED, &io->io_state);
+ spin_unlock_irq(&plo->lock);
+ }
+
dio_io_page(io, rw | WRITE | REQ_SYNC, preq, page, sec);
}
diff --git a/drivers/block/ploop/io_kaio.c b/drivers/block/ploop/io_kaio.c
index 85863df..0d731ef 100644
--- a/drivers/block/ploop/io_kaio.c
+++ b/drivers/block/ploop/io_kaio.c
@@ -614,7 +614,8 @@ kaio_read_page(struct ploop_io * io, struct ploop_request * preq,
static void
kaio_write_page(struct ploop_io * io, struct ploop_request * preq,
- struct page * page, sector_t sec, unsigned long rw)
+ struct page * page, sector_t sec, unsigned long rw,
+ int do_fsync_if_delayed)
{
ploop_prepare_tracker(preq, sec);
diff --git a/drivers/block/ploop/map.c b/drivers/block/ploop/map.c
index 1883674..96e428b 100644
--- a/drivers/block/ploop/map.c
+++ b/drivers/block/ploop/map.c
@@ -910,6 +910,7 @@ void ploop_index_update(struct ploop_request * preq)
sector_t sec;
unsigned long rw;
unsigned long state = READ_ONCE(preq->state);
+ int do_fsync_if_delayed = 0;
/* No way back, we are going to initiate index write. */
@@ -970,10 +971,13 @@ void ploop_index_update(struct ploop_request * preq)
preq->req_rw &= ~REQ_FLUSH;
/* Relocate requires consistent index update */
- if (state & (PLOOP_REQ_RELOC_A_FL|PLOOP_REQ_RELOC_S_FL))
+ if (state & (PLOOP_REQ_RELOC_A_FL|PLOOP_REQ_RELOC_S_FL)) {
rw |= (REQ_FLUSH | REQ_FUA);
+ do_fsync_if_delayed = 1;
+ }
- top_delta->io.ops->write_page(&top_delta->io, preq, page, sec, rw);
+ top_delta->io.ops->write_page(&top_delta->io, preq, page, sec, rw,
+ do_fsync_if_delayed);
put_page(page);
return;
@@ -1096,6 +1100,7 @@ static void map_wb_complete(struct map_node * m, int err)
unsigned int idx;
sector_t sec;
unsigned long rw;
+ int do_fsync_if_delayed = 0;
/* First, complete processing of written back indices,
* finally instantiate indices in mapping cache.
@@ -1193,8 +1198,10 @@ static void map_wb_complete(struct map_node * m, int err)
state = READ_ONCE(preq->state);
/* Relocate requires consistent index update */
- if (state & (PLOOP_REQ_RELOC_A_FL|PLOOP_REQ_RELOC_S_FL))
+ if (state & (PLOOP_REQ_RELOC_A_FL|PLOOP_REQ_RELOC_S_FL)) {
rw |= (REQ_FLUSH | REQ_FUA);
+ do_fsync_if_delayed = 1;
+ }
preq->eng_state = PLOOP_E_INDEX_WB;
get_page(page);
@@ -1221,8 +1228,8 @@ static void map_wb_complete(struct map_node * m, int err)
plo->st.map_multi_writes++;
top_delta->ops->map_index(top_delta, m->mn_start, &sec);
- top_delta->io.ops->write_page(&top_delta->io, main_preq, page, sec,
- rw);
+ top_delta->io.ops->write_page(&top_delta->io, main_preq, page, sec, rw,
+ do_fsync_if_delayed);
put_page(page);
}
diff --git a/include/linux/ploop/ploop.h b/include/linux/ploop/ploop.h
index deee8a7..b03565b 100644
--- a/include/linux/ploop/ploop.h
+++ b/include/linux/ploop/ploop.h
@@ -164,7 +164,8 @@ struct ploop_io_ops
void (*read_page)(struct ploop_io * io, struct ploop_request * preq,
struct page * page, sector_t sec);
void (*write_page)(struct ploop_io * io, struct ploop_request * preq,
- struct page * page, sector_t sec, unsigned long rw);
+ struct page * page, sector_t sec, unsigned long rw,
+ int do_fsync_if_delayed);
int (*sync_read)(struct ploop_io * io, struct page * page,
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