[PATCH 003/206] Staging: hv: Fix some locking issues

K. Y. Srinivasan
2011-05-09T21:44:46Z

Additional lock related cleanup. Properly serialize access to
state even for command related operations.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Abhishek Kane <v-abkane@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
---
drivers/staging/hv/blkvsc_drv.c | 31 +++++++++++++++----------------
1 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/staging/hv/blkvsc_drv.c b/drivers/staging/hv/blkvsc_drv.c
index 74d51bb..8a577bc 100644
--- a/drivers/staging/hv/blkvsc_drv.c
+++ b/drivers/staging/hv/blkvsc_drv.c
@@ -331,10 +331,14 @@ static void blkvsc_cmd_completion(struct hv_storvsc_request *request)
(struct block_device_context *)blkvsc_req->dev;
struct scsi_sense_hdr sense_hdr;
struct vmscsi_request *vm_srb;
+ unsigned long flags;

vm_srb = &blkvsc_req->request.vstor_packet.vm_srb;
+
+ spin_lock_irqsave(&blkdev->lock, flags);
blkdev->num_outstanding_reqs--;
+ spin_unlock_irqrestore(&blkdev->lock, flags);

if (vm_srb->scsi_status)
if (scsi_normalize_sense(blkvsc_req->sense_buffer,
@@ -354,6 +358,7 @@ static int blkvsc_do_operation(struct block_device_context *blkdev,
unsigned char device_type;
struct scsi_sense_hdr sense_hdr;
struct vmscsi_request *vm_srb;
+ unsigned long flags;

int ret = 0;

@@ -407,7 +412,9 @@ static int blkvsc_do_operation(struct block_device_context *blkdev,
goto cleanup;
}

+ spin_lock_irqsave(&blkdev->lock, flags);
blkvsc_submit_request(blkvsc_req, blkvsc_cmd_completion);
+ spin_unlock_irqrestore(&blkdev->lock, flags);

wait_for_completion_interruptible(&blkvsc_req->request.wait_event);

@@ -555,6 +562,8 @@ static int blkvsc_remove(struct hv_device *dev)

blk_stop_queue(blkdev->gd->queue);

+ blkvsc_cancel_pending_reqs(blkdev);
+
spin_unlock_irqrestore(&blkdev->lock, flags);

while (blkdev->num_outstanding_reqs) {
@@ -563,13 +572,8 @@ static int blkvsc_remove(struct hv_device *dev)
udelay(100);
}

- blkvsc_do_operation(blkdev, DO_FLUSH);
-
- spin_lock_irqsave(&blkdev->lock, flags);

- blkvsc_cancel_pending_reqs(blkdev);
-
- spin_unlock_irqrestore(&blkdev->lock, flags);
+ blkvsc_do_operation(blkdev, DO_FLUSH);

blk_cleanup_queue(blkdev->gd->queue);

@@ -597,6 +601,8 @@ static void blkvsc_shutdown(struct hv_device *dev)

blk_stop_queue(blkdev->gd->queue);

+ blkvsc_cancel_pending_reqs(blkdev);
+
spin_unlock_irqrestore(&blkdev->lock, flags);

while (blkdev->num_outstanding_reqs) {
@@ -605,13 +611,9 @@ static void blkvsc_shutdown(struct hv_device *dev)
udelay(100);
}

- blkvsc_do_operation(blkdev, DO_FLUSH);

- spin_lock_irqsave(&blkdev->lock, flags);
-
- blkvsc_cancel_pending_reqs(blkdev);
+ blkvsc_do_operation(blkdev, DO_FLUSH);

- spin_unlock_irqrestore(&blkdev->lock, flags);
}

static int blkvsc_release(struct gendisk *disk, fmode_t mode)
@@ -619,16 +621,14 @@ static int blkvsc_release(struct gendisk *disk, fmode_t mode)
struct block_device_context *blkdev = disk->private_data;
unsigned long flags;

- spin_lock_irqsave(&blkdev->lock, flags);
if (blkdev->users == 1) {
- spin_unlock_irqrestore(&blkdev->lock, flags);
blkvsc_do_operation(blkdev, DO_FLUSH);
- spin_lock_irqsave(&blkdev->lock, flags);
}

+ spin_lock_irqsave(&blkdev->lock, flags);
blkdev->users--;
-
spin_unlock_irqrestore(&blkdev->lock, flags);
+
return 0;
}

@@ -943,7 +943,6 @@ static int blkvsc_probe(struct hv_device *dev)
struct storvsc_major_info major_info;
int ret = 0;

-
blkdev = kzalloc(sizeof(struct block_device_context), GFP_KERNEL);
if (!blkdev) {
ret = -ENOMEM;
--
1.7.4.1