The commit is pushed to "branch-rh9-5.14.0-427.44.1.vz9.80.x-ovz" and will
appear at g...@bitbucket.org:openvz/vzkernel.git
after rh9-5.14.0-427.44.1.vz9.80.6
------>
commit 8a037103fe00c081c335ca618580525d9b92027f
Author: Alexander Atanasov <alexander.atana...@virtuozzo.com>
Date: Fri Jan 24 17:36:27 2025 +0200
dm-ploop: fix how ENOTBLK is handled
direct IO write result ENOTBLK or 0(in ext4 case) means
retry IO in buffered mode. We wrongly assumed that it is
a short write and handled it incorrectly
Since we can not retry in buffered mode, code is not ready
for it. Take a different route. This error happens if
page invalidation fails, which is a very rare situation.
So call synchronize_rcu() and just resubmit pio.
Try this three times and end pio with error.
https://virtuozzo.atlassian.net/browse/VSTOR-91821
Suggested-by: Alexey Kuznetsov <kuz...@virtuozzo.com>
Signed-off-by: Alexander Atanasov <alexander.atana...@virtuozzo.com>
======
Patchset description:
ploop: optimistations and scalling
Ploop processes requsts in a different threads in parallel
where possible which results in significant improvement in
performance and makes further optimistations possible.
Known bugs:
- delayed metadata writeback is not working and is missing error handling
- patch to disable it until fixed
- fast path is not working - causes rcu lockups - patch to disable it
Further improvements:
- optimize md pages lookups
Alexander Atanasov (50):
dm-ploop: md_pages map all pages at creation time
dm-ploop: Use READ_ONCE/WRITE_ONCE to access md page data
dm-ploop: fsync after all pios are sent
dm-ploop: move md status to use proper bitops
dm-ploop: convert wait_list and wb_batch_llist to use lockless lists
dm-ploop: convert enospc handling to use lockless lists
dm-ploop: convert suspended_pios list to use lockless list
dm-ploop: convert the rest of the lists to use llist variant
dm-ploop: combine processing of pios thru prepare list and remove
fsync worker
dm-ploop: move from wq to kthread
dm-ploop: move preparations of pios into the caller from worker
dm-ploop: fast path execution for reads
dm-ploop: do not use a wrapper for set_bit to make a page writeback
dm-ploop: BAT use only one list for writeback
dm-ploop: make md writeback timeout to be per page
dm-ploop: add interface to disable bat writeback delay
dm-ploop: convert wb_batch_list to lockless variant
dm-ploop: convert high_prio to status
dm-ploop: split cow processing into two functions
dm-ploop: convert md page rw lock to spin lock
dm-ploop: convert bat_rwlock to bat_lock spinlock
dm-ploop: prepare bat updates under bat_lock
dm-ploop: make ploop_bat_write_complete ready for parallel pio
completion
dm-ploop: make ploop_submit_metadata_writeback return number of
requests sent
dm-ploop: introduce pio runner threads
dm-ploop: add pio list ids to be used when passing pios to runners
dm-ploop: process pios via runners
dm-ploop: disable metadata writeback delay
dm-ploop: disable fast path
dm-ploop: use lockless lists for chained cow updates list
dm-ploop: use lockless lists for data ready pios
dm-ploop: give runner threads better name
dm-ploop: resize operation - add holes bitmap locking
dm-ploop: remove unnecessary operations
dm-ploop: use filp per thread
dm-ploop: catch if we try to advance pio past bio end
dm-ploop: support REQ_FUA for data pios
dm-ploop: proplerly access nr_bat_entries
dm-ploop: fix locking and improve error handling when submitting pios
dm-ploop: fix how ENOTBLK is handled
dm-ploop: sync when suspended or stopping
dm-ploop: rework bat completion logic
dm-ploop: rework logic in pio processing
dm-ploop: end fsync pios in parallel
dm-ploop: make filespace preallocations async
dm-ploop: resubmit enospc pios from dispatcher thread
dm-ploop: dm-ploop: simplify discard completion
dm-ploop: use GFP_ATOMIC instead of GFP_NOIO
dm-ploop: fix locks used in mixed context
dm-ploop: fix how current flags are managed inside threads
Andrey Zhadchenko (13):
dm-ploop: do not flush after metadata writes
dm-ploop: set IOCB_DSYNC on all FUA requests
dm-ploop: remove extra ploop_cluster_is_in_top_delta()
dm-ploop: introduce per-md page locking
dm-ploop: reduce BAT accesses on discard completion
dm-ploop: simplify llseek
dm-ploop: speed up ploop_prepare_bat_update()
dm-ploop: make new allocations immediately visible in BAT
dm-ploop: drop ploop_cluster_is_in_top_delta()
dm-ploop: do not wait for BAT update for non-FUA requests
dm-ploop: add delay for metadata writeback
dm-ploop: submit all postponed metadata on REQ_OP_FLUSH
dm-ploop: handle REQ_PREFLUSH
Feature: dm-ploop: ploop target driver
---
drivers/md/dm-ploop-map.c | 31 +++++++++++++++++++++++--------
drivers/md/dm-ploop.h | 1 +
2 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index dc150c8050d9..7d5e2cf443ee 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -94,6 +94,7 @@ void ploop_init_pio(struct ploop *ploop, unsigned int bi_op,
struct pio *pio)
/* FIXME: assign real clu? */
pio->clu = UINT_MAX;
pio->level = BAT_LEVEL_INVALID;
+ pio->retries = 0;
}
/* Check that rq end byte is not behind end of device */
@@ -1322,18 +1323,32 @@ static void ploop_data_rw_complete(struct pio *pio)
bool completed;
if (pio->ret != pio->bi_iter.bi_size) {
- if (pio->ret >= 0) {
- /* Partial IO */
- WARN_ON_ONCE(pio->ret == 0);
- /* Do not resubmit zero length pio */
+ if (pio->ret >= 0 || pio->ret == -ENOTBLK) {
+ /* Partial IO or request to retry in buffered mode */
+ if (pio->ret == 0 || pio->ret == -ENOTBLK) {
+ /*
+ * ENOTBLK means we should retry in buffered io
+ * but we can not, so try again in DIO
+ * ext4 returns 0 for ENOTBLK
+ */
+ struct ploop *ploop = pio->ploop;
+
+ if (pio->retries++ < 3) {
+ PL_ERR("ret = 0 bi_size=%d\n",
pio->bi_iter.bi_size);
+ synchronize_rcu();
+ ploop_queue_resubmit(pio);
+ } else {
+ /* we retried but still failed */
+ pio->bi_status = BLK_STS_IOERR;
+ goto check_da;
+ }
+ }
+
if (pio->ret > 0) {
ploop_pio_advance(pio, pio->ret);
ploop_queue_resubmit(pio);
- return;
- } else {
- pio->bi_status = BLK_STS_IOERR;
- goto check_da;
}
+ return;
}
if (static_branch_unlikely(&ploop_standby_check))
ploop_check_standby_mode(pio->ploop, pio->ret);
diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
index 9f193afab618..11e50ab1293b 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -315,6 +315,7 @@ struct pio {
unsigned int runner_id;
atomic_t md_inflight;
+ unsigned char retries;
};
/* Delta COW private */
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