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Groups > linux.kernel > #1738309
| From | Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.18 40/42] bcache: fix for gc and write-back race |
| Date | 2017-09-24 22:40 +0200 |
| Message-ID | <utlR0-4Ti-37@gated-at.bofh.it> (permalink) |
| References | <utlHj-4Np-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tang Junhui <tang.junhui@zte.com.cn>
commit 9baf30972b5568d8b5bc8b3c46a6ec5b58100463 upstream.
gc and write-back get raced (see the email "bcache get stucked" I sended
before):
gc thread write-back thread
| |bch_writeback_thread()
|bch_gc_thread() |
| |==>read_dirty()
|==>bch_btree_gc() |
|==>btree_root() //get btree root |
| //node write locker |
|==>bch_btree_gc_root() |
| |==>read_dirty_submit()
| |==>write_dirty()
| |==>continue_at(cl,
| | write_dirty_finish,
| | system_wq);
| |==>write_dirty_finish()//excute
| | //in system_wq
| |==>bch_btree_insert()
| |==>bch_btree_map_leaf_nodes()
| |==>__bch_btree_map_nodes()
| |==>btree_root //try to get btree
| | //root node read
| | //lock
| |-----stuck here
|==>bch_btree_set_root()
|==>bch_journal_meta()
|==>bch_journal()
|==>journal_try_write()
|==>journal_write_unlocked() //journal_full(&c->journal)
| //condition satisfied
|==>continue_at(cl, journal_write, system_wq); //try to excute
| //journal_write in system_wq
| //but work queue is excuting
| //write_dirty_finish()
|==>closure_sync(); //wait journal_write execute
| //over and wake up gc,
|-------------stuck here
|==>release root node write locker
This patch alloc a separate work-queue for write-back thread to avoid such
race.
(Commit log re-organized by Coly Li to pass checkpatch.pl checking)
Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/md/bcache/bcache.h | 1 +
drivers/md/bcache/super.c | 2 ++
drivers/md/bcache/writeback.c | 9 +++++++--
3 files changed, 10 insertions(+), 2 deletions(-)
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -348,6 +348,7 @@ struct cached_dev {
/* Limit number of writeback bios in flight */
struct semaphore in_flight;
struct task_struct *writeback_thread;
+ struct workqueue_struct *writeback_write_wq;
struct keybuf writeback_keys;
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1087,6 +1087,8 @@ static void cached_dev_free(struct closu
cancel_delayed_work_sync(&dc->writeback_rate_update);
if (!IS_ERR_OR_NULL(dc->writeback_thread))
kthread_stop(dc->writeback_thread);
+ if (dc->writeback_write_wq)
+ destroy_workqueue(dc->writeback_write_wq);
mutex_lock(&bch_register_lock);
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -191,7 +191,7 @@ static void write_dirty(struct closure *
closure_bio_submit(&io->bio, cl, &io->dc->disk);
- continue_at(cl, write_dirty_finish, system_wq);
+ continue_at(cl, write_dirty_finish, io->dc->writeback_write_wq);
}
static void read_dirty_endio(struct bio *bio, int error)
@@ -211,7 +211,7 @@ static void read_dirty_submit(struct clo
closure_bio_submit(&io->bio, cl, &io->dc->disk);
- continue_at(cl, write_dirty, system_wq);
+ continue_at(cl, write_dirty, io->dc->writeback_write_wq);
}
static void read_dirty(struct cached_dev *dc)
@@ -523,6 +523,11 @@ void bch_cached_dev_writeback_init(struc
int bch_cached_dev_writeback_start(struct cached_dev *dc)
{
+ dc->writeback_write_wq = alloc_workqueue("bcache_writeback_wq",
+ WQ_MEM_RECLAIM, 0);
+ if (!dc->writeback_write_wq)
+ return -ENOMEM;
+
dc->writeback_thread = kthread_create(bch_writeback_thread, dc,
"bcache_writeback");
if (IS_ERR(dc->writeback_thread))
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[PATCH 3.18 00/42] 3.18.72-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 11/42] [PATCH - RESEND] crypto: AF_ALG - remove SGL terminator indicator when chaining Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 25/42] scsi: sg: use standard lists for sg_requests Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 03/42] Revert "net: phy: Correctly process PHY_HALTED in phy_stop_machine()" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 42/42] mac80211: flush hw_roc_start work before cancelling the ROC Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 05/42] ipv6: fix memory leak with multiple tables during netns destruction Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 27/42] scsi: sg: factor out sg_fill_request_table() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 12/42] ext4: fix incorrect quotaoff if the quota feature is enabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 01/42] ipv6: accept 64k - 1 packet length in ip6_find_1stfragopt() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 21/42] scsi: zfcp: fix payload with full FCP_RSP IU in SCSI trace records Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 29/42] scsi: qla2xxx: Fix an integer overflow in sysfs code Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 08/42] [PATCH] Revert "usb: musb: fix tx fifo flush handling again" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 16/42] skd: Avoid that module unloading triggers a use-after-free Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 30/42] ftrace: Fix selftest goto location on error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 07/42] f2fs: check hot_data for roll-forward recovery Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 37/42] bcache: Fix leak of bdev reference Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 40/42] bcache: fix for gc and write-back race Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 39/42] bcache: Correct return value for sysfs attach errors Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 41/42] bcache: fix bch_hprint crash and improve output Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 33/42] PCI: shpchp: Enable bridge bus mastering if MSI is enabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 06/42] ipv6: fix typo in fib6_net_exit() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 31/42] tracing: Apply trace_clock changes to instance max buffer Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 38/42] bcache: correct cache_dirty_target in __update_writeback_rate() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 32/42] ARC: Re-enable MMU upon Machine Check exception Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 28/42] scsi: sg: fixup infoleak when using SG_GET_REQUEST_TABLE Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 34/42] media: v4l2-compat-ioctl32: Fix timespec conversion Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 04/42] tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 35/42] media: uvcvideo: Prevent heap overflow when accessing mapped controls Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 24/42] scsi: sg: remove save_scat_len Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 14/42] block: Relax a check in blk_start_queue() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 18/42] scsi: zfcp: fix queuecommand for scsi_eh commands when DIX enabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 22/42] scsi: zfcp: trace HBA FSF response by default on dismiss or timedout late response Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 26/42] scsi: sg: off by one in sg_ioctl() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 23/42] scsi: zfcp: trace high part of "new" 64 bit SCSI LUN Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 02/42] qlge: avoid memcpy buffer overflow Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 13/42] powerpc: Fix DAR reporting when alignment handler faults Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
Re: [PATCH 3.18 00/42] 3.18.72-stable review Guenter Roeck <linux@roeck-us.net> - 2017-09-25 03:10 +0200
Re: [PATCH 3.18 00/42] 3.18.72-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-25 08:40 +0200
Re: [PATCH 3.18 00/42] 3.18.72-stable review Guenter Roeck <linux@roeck-us.net> - 2017-09-25 13:10 +0200
Re: [PATCH 3.18 00/42] 3.18.72-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-25 14:30 +0200
Re: [PATCH 3.18 00/42] 3.18.72-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-09-26 01:20 +0200
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