Implement the ->free_disk method to to put struct scsi_disk when the last
gendisk reference count goes away. This removes the need to clear
->private_data and thus freeze the queue on unbind.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
---
drivers/scsi/sd.c | 90 +++++++++--------------------------------------
1 file changed, 16 insertions(+), 74 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 346b8d62de7d1..73e6f5f0f37c2 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -121,11 +121,6 @@ static void scsi_disk_release(struct device *cdev);
static DEFINE_IDA(sd_index_ida);
-/* This semaphore is used to mediate the 0->1 reference get in the
- * face of object destruction (i.e. we can't allow a get on an
- * object after last put) */
-static DEFINE_MUTEX(sd_ref_mutex);
-
static struct kmem_cache *sd_cdb_cache;
static mempool_t *sd_cdb_pool;
static mempool_t *sd_page_pool;
@@ -663,33 +658,6 @@ static int sd_major(int major_idx)
}
}
-static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
-{
- struct scsi_disk *sdkp = NULL;
-
- mutex_lock(&sd_ref_mutex);
-
- if (disk->private_data) {
- sdkp = scsi_disk(disk);
- if (scsi_device_get(sdkp->device) == 0)
- get_device(&sdkp->disk_dev);
- else
- sdkp = NULL;
- }
- mutex_unlock(&sd_ref_mutex);
- return sdkp;
-}
-
-static void scsi_disk_put(struct scsi_disk *sdkp)
-{
- struct scsi_device *sdev = sdkp->device;
-
- mutex_lock(&sd_ref_mutex);
- put_device(&sdkp->disk_dev);
- scsi_device_put(sdev);
- mutex_unlock(&sd_ref_mutex);
-}
-
#ifdef CONFIG_BLK_SED_OPAL
static int sd_sec_submit(void *data, u16 spsp, u8 secp, void *buffer,
size_t len, bool send)
@@ -1418,17 +1386,15 @@ static bool sd_need_revalidate(struct block_device *bdev,
**/
static int sd_open(struct block_device *bdev, fmode_t mode)
{
- struct scsi_disk *sdkp = scsi_disk_get(bdev->bd_disk);
- struct scsi_device *sdev;
+ struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
+ struct scsi_device *sdev = sdkp->device;
int retval;
- if (!sdkp)
+ if (scsi_device_get(sdev))
return -ENXIO;
SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
- sdev = sdkp->device;
-
/*
* If the device is in error recovery, wait until it is done.
* If the device is offline, then disallow any access to it.
@@ -1473,7 +1439,7 @@ static int sd_open(struct block_device *bdev, fmode_t mode)
return 0;
error_out:
- scsi_disk_put(sdkp);
+ scsi_device_put(sdev);
return retval;
}
@@ -1502,7 +1468,7 @@ static void sd_release(struct gendisk *disk, fmode_t mode)
scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
}
- scsi_disk_put(sdkp);
+ scsi_device_put(sdev);
}
static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
@@ -1616,7 +1582,7 @@ static int media_not_present(struct scsi_disk *sdkp,
**/
static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
{
- struct scsi_disk *sdkp = scsi_disk_get(disk);
+ struct scsi_disk *sdkp = disk->private_data;
struct scsi_device *sdp;
int retval;
bool disk_changed;
@@ -1679,7 +1645,6 @@ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
*/
disk_changed = sdp->changed;
sdp->changed = 0;
- scsi_disk_put(sdkp);
return disk_changed ? DISK_EVENT_MEDIA_CHANGE : 0;
}
@@ -1887,6 +1852,13 @@ static const struct pr_ops sd_pr_ops = {
.pr_clear = sd_pr_clear,
};
+static void scsi_disk_free_disk(struct gendisk *disk)
+{
+ struct scsi_disk *sdkp = scsi_disk(disk);
+
+ put_device(&sdkp->disk_dev);
+}
+
static const struct block_device_operations sd_fops = {
.owner = THIS_MODULE,
.open = sd_open,
@@ -1898,6 +1870,7 @@ static const struct block_device_operations sd_fops = {
.unlock_native_capacity = sd_unlock_native_capacity,
.report_zones = sd_zbc_report_zones,
.get_unique_id = sd_get_unique_id,
+ .free_disk = scsi_disk_free_disk,
.pr_ops = &sd_pr_ops,
};
@@ -3623,54 +3596,23 @@ static int sd_probe(struct device *dev)
**/
static int sd_remove(struct device *dev)
{
- struct scsi_disk *sdkp;
+ struct scsi_disk *sdkp = dev_get_drvdata(dev);
- sdkp = dev_get_drvdata(dev);
scsi_autopm_get_device(sdkp->device);
device_del(&sdkp->disk_dev);
del_gendisk(sdkp->disk);
sd_shutdown(dev);
- mutex_lock(&sd_ref_mutex);
- dev_set_drvdata(dev, NULL);
- put_device(&sdkp->disk_dev);
- mutex_unlock(&sd_ref_mutex);
-
+ put_disk(sdkp->disk);
return 0;
}
-/**
- * scsi_disk_release - Called to free the scsi_disk structure
- * @dev: pointer to embedded class device
- *
- * sd_ref_mutex must be held entering this routine. Because it is
- * called on last put, you should always use the scsi_disk_get()
- * scsi_disk_put() helpers which manipulate the semaphore directly
- * and never do a direct put_device.
- **/
static void scsi_disk_release(struct device *dev)
{
struct scsi_disk *sdkp = to_scsi_disk(dev);
- struct gendisk *disk = sdkp->disk;
- struct request_queue *q = disk->queue;
ida_free(&sd_index_ida, sdkp->index);
-
- /*
- * Wait until all requests that are in progress have completed.
- * This is necessary to avoid that e.g. scsi_end_request() crashes
- * due to clearing the disk->private_data pointer. Wait from inside
- * scsi_disk_release() instead of from sd_release() to avoid that
- * freezing and unfreezing the request queue affects user space I/O
- * in case multiple processes open a /dev/sd... node concurrently.
- */
- blk_mq_freeze_queue(q);
- blk_mq_unfreeze_queue(q);
-
- disk->private_data = NULL;
- put_disk(disk);
-
sd_zbc_release_disk(sdkp);
put_device(&sdkp->device->sdev_gendev);
free_opal_dev(sdkp->opal_dev);
--
2.30.2
