diff options
| author | Logan Gunthorpe <logang@deltatee.com> | 2022-06-08 19:27:51 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-08-03 02:14:31 +0300 |
| commit | 7769085c8d4d7aad4e68f2f4f2077bd46449511f (patch) | |
| tree | 69312769f828206bc29df5dc90125056bca17131 /drivers/md | |
| parent | 78ede6a06f011b47d3c2c9dd5699b05bc3bf2dae (diff) | |
| download | linux-7769085c8d4d7aad4e68f2f4f2077bd46449511f.tar.xz | |
md/raid5-cache: Drop RCU usage of conf->log
The only place that uses RCU to access conf->log is in
r5l_log_disk_error(). This function is mostly used in the IO path
and once with mddev_lock() held in raid5_change_consistency_policy().
It is known that the IO will be suspended before the log is freed and
r5l_log_exit() is called with the mddev_lock() held.
This should mean that conf->log can not be freed while the function is
being called, so the RCU protection is not necessary. Drop the
rcu_read_lock() as well as the synchronize_rcu() and
rcu_assign_pointer() usage.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5-cache.c | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 4da88888fbfc..d9b94e25e815 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -1590,18 +1590,13 @@ void r5l_quiesce(struct r5l_log *log, int quiesce) bool r5l_log_disk_error(struct r5conf *conf) { - struct r5l_log *log; - bool ret; - /* don't allow write if journal disk is missing */ - rcu_read_lock(); - log = rcu_dereference(conf->log); + struct r5l_log *log = conf->log; + /* don't allow write if journal disk is missing */ if (!log) - ret = test_bit(MD_HAS_JOURNAL, &conf->mddev->flags); + return test_bit(MD_HAS_JOURNAL, &conf->mddev->flags); else - ret = test_bit(Faulty, &log->rdev->flags); - rcu_read_unlock(); - return ret; + return test_bit(Faulty, &log->rdev->flags); } #define R5L_RECOVERY_PAGE_POOL_SIZE 256 @@ -3148,7 +3143,7 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev) spin_lock_init(&log->stripe_in_journal_lock); atomic_set(&log->stripe_in_journal_count, 0); - rcu_assign_pointer(conf->log, log); + conf->log = log; set_bit(MD_HAS_JOURNAL, &conf->mddev->flags); return 0; @@ -3171,7 +3166,6 @@ void r5l_exit_log(struct r5conf *conf) struct r5l_log *log = conf->log; conf->log = NULL; - synchronize_rcu(); /* Ensure disable_writeback_work wakes up and exits */ wake_up(&conf->mddev->sb_wait); |