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authorChristoph Hellwig <hch@lst.de>2014-09-14 06:41:16 +0400
committerChristoph Hellwig <hch@lst.de>2014-11-12 13:19:22 +0300
commit27c888f0bb889693c6a3b6d39eba3265c16c072f (patch)
tree26513aa57507d3bac7e027eb8561d3d555d8f44d /drivers/scsi/device_handler
parent0b9c08442c5d0991dd1632fed63221f5b6a35e83 (diff)
downloadlinux-27c888f0bb889693c6a3b6d39eba3265c16c072f.tar.xz
scsi_dh: get module reference outside of device handler
We need to grab a reference to the module before calling the attach routines to avoid a small race vs module removal. It also cleans up the code significantly as a side effect. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Hannes Reinecke <hare@suse.de>
Diffstat (limited to 'drivers/scsi/device_handler')
-rw-r--r--drivers/scsi/device_handler/scsi_dh.c31
-rw-r--r--drivers/scsi/device_handler/scsi_dh_alua.c4
-rw-r--r--drivers/scsi/device_handler/scsi_dh_emc.c4
-rw-r--r--drivers/scsi/device_handler/scsi_dh_hp_sw.c4
-rw-r--r--drivers/scsi/device_handler/scsi_dh_rdac.c4
5 files changed, 22 insertions, 25 deletions
diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c
index 33e422e75835..1a8dbf33f2ac 100644
--- a/drivers/scsi/device_handler/scsi_dh.c
+++ b/drivers/scsi/device_handler/scsi_dh.c
@@ -102,23 +102,36 @@ static int scsi_dh_handler_attach(struct scsi_device *sdev,
if (sdev->scsi_dh_data) {
if (sdev->scsi_dh_data->scsi_dh != scsi_dh)
- err = -EBUSY;
- else
- kref_get(&sdev->scsi_dh_data->kref);
- } else if (scsi_dh->attach) {
+ return -EBUSY;
+
+ kref_get(&sdev->scsi_dh_data->kref);
+ return 0;
+ }
+
+ if (scsi_dh->attach) {
+ if (!try_module_get(scsi_dh->module))
+ return -EINVAL;
+
err = scsi_dh->attach(sdev);
- if (!err) {
- kref_init(&sdev->scsi_dh_data->kref);
- sdev->scsi_dh_data->sdev = sdev;
+ if (err) {
+ module_put(scsi_dh->module);
+ return err;
}
+
+ kref_init(&sdev->scsi_dh_data->kref);
+ sdev->scsi_dh_data->sdev = sdev;
}
return err;
}
static void __detach_handler (struct kref *kref)
{
- struct scsi_dh_data *scsi_dh_data = container_of(kref, struct scsi_dh_data, kref);
- scsi_dh_data->scsi_dh->detach(scsi_dh_data->sdev);
+ struct scsi_dh_data *scsi_dh_data =
+ container_of(kref, struct scsi_dh_data, kref);
+ struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh;
+
+ scsi_dh->detach(scsi_dh_data->sdev);
+ module_put(scsi_dh->module);
}
/*
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index fd78bdc53528..9115c31f26e9 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -873,9 +873,6 @@ static int alua_bus_attach(struct scsi_device *sdev)
if ((err != SCSI_DH_OK) && (err != SCSI_DH_DEV_OFFLINED))
goto failed;
- if (!try_module_get(THIS_MODULE))
- goto failed;
-
spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
sdev->scsi_dh_data = scsi_dh_data;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
@@ -908,7 +905,6 @@ static void alua_bus_detach(struct scsi_device *sdev)
if (h->buff && h->inq != h->buff)
kfree(h->buff);
kfree(scsi_dh_data);
- module_put(THIS_MODULE);
sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", ALUA_DH_NAME);
}
diff --git a/drivers/scsi/device_handler/scsi_dh_emc.c b/drivers/scsi/device_handler/scsi_dh_emc.c
index 84765384c47c..153b4c3547a2 100644
--- a/drivers/scsi/device_handler/scsi_dh_emc.c
+++ b/drivers/scsi/device_handler/scsi_dh_emc.c
@@ -692,9 +692,6 @@ static int clariion_bus_attach(struct scsi_device *sdev)
if (err != SCSI_DH_OK)
goto failed;
- if (!try_module_get(THIS_MODULE))
- goto failed;
-
spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
sdev->scsi_dh_data = scsi_dh_data;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
@@ -728,7 +725,6 @@ static void clariion_bus_detach(struct scsi_device *sdev)
CLARIION_NAME);
kfree(scsi_dh_data);
- module_put(THIS_MODULE);
}
static int __init clariion_init(void)
diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
index 4824bfbe3051..cf36557a1d4d 100644
--- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@@ -377,9 +377,6 @@ static int hp_sw_bus_attach(struct scsi_device *sdev)
if (ret != SCSI_DH_OK || h->path_state == HP_SW_PATH_UNINITIALIZED)
goto failed;
- if (!try_module_get(THIS_MODULE))
- goto failed;
-
spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
sdev->scsi_dh_data = scsi_dh_data;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
@@ -406,7 +403,6 @@ static void hp_sw_bus_detach( struct scsi_device *sdev )
scsi_dh_data = sdev->scsi_dh_data;
sdev->scsi_dh_data = NULL;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
- module_put(THIS_MODULE);
sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", HP_SW_NAME);
diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
index 1b5bc9293e37..b850954c4e22 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -878,9 +878,6 @@ static int rdac_bus_attach(struct scsi_device *sdev)
if (err != SCSI_DH_OK)
goto clean_ctlr;
- if (!try_module_get(THIS_MODULE))
- goto clean_ctlr;
-
spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
sdev->scsi_dh_data = scsi_dh_data;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
@@ -924,7 +921,6 @@ static void rdac_bus_detach( struct scsi_device *sdev )
kref_put(&h->ctlr->kref, release_controller);
spin_unlock(&list_lock);
kfree(scsi_dh_data);
- module_put(THIS_MODULE);
sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME);
}