From 8d58881b995904bf8b150dae69be0829f832e7be Mon Sep 17 00:00:00 2001 From: Bart Van Assche <bart.vanassche@sandisk.com> Date: Thu, 22 Sep 2016 14:20:54 -0700 Subject: scsi: Avoid that toggling use_blk_mq triggers a memory leak This patch avoids that the following memory leak is triggered if use_blk_mq is disabled after a SCSI host has been allocated by the ib_srp driver and before the same SCSI host is freed: unreferenced object 0xffff8803a168c568 (size 256): backtrace: [<ffffffff81620c95>] kmemleak_alloc+0x45/0xa0 [<ffffffff811bb104>] __kmalloc_node+0x1e4/0x400 [<ffffffff81309fe4>] blk_mq_alloc_tag_set+0xb4/0x230 [<ffffffff814731b7>] scsi_mq_setup_tags+0xc7/0xd0 [<ffffffff81469c26>] scsi_add_host_with_dma+0x216/0x2d0 [<ffffffffa064bef5>] srp_create_target+0xe55/0x13d0 [ib_srp] [<ffffffff8143ce23>] dev_attr_store+0x13/0x20 [<ffffffff8125f030>] sysfs_kf_write+0x40/0x50 [<ffffffff8125e397>] kernfs_fop_write+0x137/0x1c0 [<ffffffff811d8c13>] __vfs_write+0x23/0x140 [<ffffffff811d92e0>] vfs_write+0xb0/0x190 [<ffffffff811da5b4>] SyS_write+0x44/0xa0 [<ffffffff8162c8a5>] entry_SYSCALL_64_fastpath+0x18/0xa8 Fixes: 9aa9cc4221f5 ("scsi: remove the disable_blk_mq host flag") Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: <stable@vger.kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> --- drivers/scsi/hosts.c | 2 ++ drivers/scsi/scsi.c | 1 - drivers/scsi/scsi_priv.h | 1 + 3 files changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/scsi') diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index ba9af4a2bd2a..ec6381e57eb7 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -486,6 +486,8 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) else shost->dma_boundary = 0xffffffff; + shost->use_blk_mq = scsi_use_blk_mq; + device_initialize(&shost->shost_gendev); dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); shost->shost_gendev.bus = &scsi_bus_type; diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 1f36aca44394..1deb6adc411f 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -1160,7 +1160,6 @@ bool scsi_use_blk_mq = true; bool scsi_use_blk_mq = false; #endif module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO); -EXPORT_SYMBOL_GPL(scsi_use_blk_mq); static int __init init_scsi(void) { diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 57a4b9973320..85c8a51bc563 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -29,6 +29,7 @@ extern int scsi_init_hosts(void); extern void scsi_exit_hosts(void); /* scsi.c */ +extern bool scsi_use_blk_mq; extern int scsi_setup_command_freelist(struct Scsi_Host *shost); extern void scsi_destroy_command_freelist(struct Scsi_Host *shost); #ifdef CONFIG_SCSI_LOGGING -- cgit v1.2.3-70-g09d2