diff options
| author | Bart Van Assche <bart.vanassche@wdc.com> | 2017-12-04 19:06:23 +0100 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2017-12-08 03:06:31 +0100 |
| commit | 3bd6f43f5cb3714f70c591514f344389df593501 (patch) | |
| tree | 0d287d0b562c064adf4ce1b45c1ea0cb2b97b401 /drivers/scsi/hosts.c | |
| parent | rcu: Export init_rcu_head() and destroy_rcu_head() to GPL modules (diff) | |
| download | linux-3bd6f43f5cb3714f70c591514f344389df593501.tar.xz linux-3bd6f43f5cb3714f70c591514f344389df593501.zip | |
scsi: core: Ensure that the SCSI error handler gets woken up
If scsi_eh_scmd_add() is called concurrently with
scsi_host_queue_ready() while shost->host_blocked > 0 then it can
happen that neither function wakes up the SCSI error handler. Fix
this by making every function that decreases the host_busy counter
wake up the error handler if necessary and by protecting the
host_failed checks with the SCSI host lock.
Reported-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
References: https://marc.info/?l=linux-kernel&m=150461610630736
Fixes: commit 746650160866 ("scsi: convert host_busy to atomic_t")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Tested-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: Stuart Hayes <stuart.w.hayes@gmail.com>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/hosts.c')
| -rw-r--r-- | drivers/scsi/hosts.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index fe3a0da3ec97..57bf43e34863 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -318,6 +318,9 @@ static void scsi_host_dev_release(struct device *dev) scsi_proc_hostdir_rm(shost->hostt); + /* Wait for functions invoked through call_rcu(&shost->rcu, ...) */ + rcu_barrier(); + if (shost->tmf_work_q) destroy_workqueue(shost->tmf_work_q); if (shost->ehandler) @@ -325,6 +328,8 @@ static void scsi_host_dev_release(struct device *dev) if (shost->work_q) destroy_workqueue(shost->work_q); + destroy_rcu_head(&shost->rcu); + if (shost->shost_state == SHOST_CREATED) { /* * Free the shost_dev device name here if scsi_host_alloc() @@ -399,6 +404,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) INIT_LIST_HEAD(&shost->starved_list); init_waitqueue_head(&shost->host_wait); mutex_init(&shost->scan_mutex); + init_rcu_head(&shost->rcu); index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL); if (index < 0) |