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sg: do not allocate a gendisk

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sg is a character driver and thus does not need to allocate a gendisk,
which is only used for file system-like block layer I/O on block
devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210816131910.615153-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2021-08-16 15:19:04 +02:00 committed by Jens Axboe
parent 45938335d0
commit aebbb5831f
1 changed files with 9 additions and 23 deletions
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32
drivers/scsi/sg.c
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@ -166,7 +166,7 @@ typedef struct sg_device { /* holds the state of each scsi generic device */
bool exclude; /* 1->open(O_EXCL) succeeded and is active */
int open_cnt; /* count of opens (perhaps < num(sfds) ) */
char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
struct gendisk *disk;
char name[DISK_NAME_LEN];
struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
struct kref d_ref;
} Sg_device;
@ -202,8 +202,7 @@ static void sg_device_destroy(struct kref *kref);
#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
#define sg_printk(prefix, sdp, fmt, a...) \
sdev_prefix_printk(prefix, (sdp)->device, \
(sdp)->disk->disk_name, fmt, ##a)
sdev_prefix_printk(prefix, (sdp)->device, (sdp)->name, fmt, ##a)
/*
* The SCSI interfaces that use read() and write() as an asynchronous variant of
@ -832,7 +831,7 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp,
srp->rq->timeout = timeout;
kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
blk_execute_rq_nowait(sdp->disk, srp->rq, at_head, sg_rq_end_io);
blk_execute_rq_nowait(NULL, srp->rq, at_head, sg_rq_end_io);
return 0;
}
@ -1119,8 +1118,7 @@ sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
return put_user(max_sectors_bytes(sdp->device->request_queue),
ip);
case BLKTRACESETUP:
return blk_trace_setup(sdp->device->request_queue,
sdp->disk->disk_name,
return blk_trace_setup(sdp->device->request_queue, NULL,
MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
NULL, p);
case BLKTRACESTART:
@ -1456,7 +1454,7 @@ static struct class *sg_sysfs_class;
static int sg_sysfs_valid = 0;
static Sg_device *
sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
sg_alloc(struct scsi_device *scsidp)
{
struct request_queue *q = scsidp->request_queue;
Sg_device *sdp;
@ -1492,9 +1490,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
"sg_alloc: dev=%d \n", k));
sprintf(disk->disk_name, "sg%d", k);
disk->first_minor = k;
sdp->disk = disk;
sprintf(sdp->name, "sg%d", k);
sdp->device = scsidp;
mutex_init(&sdp->open_rel_lock);
INIT_LIST_HEAD(&sdp->sfds);
@ -1521,19 +1517,11 @@ static int
sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
{
struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
struct gendisk *disk;
Sg_device *sdp = NULL;
struct cdev * cdev = NULL;
int error;
unsigned long iflags;
disk = alloc_disk(1);
if (!disk) {
pr_warn("%s: alloc_disk failed\n", __func__);
return -ENOMEM;
}
disk->major = SCSI_GENERIC_MAJOR;
error = -ENOMEM;
cdev = cdev_alloc();
if (!cdev) {
@ -1543,7 +1531,7 @@ sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
cdev->owner = THIS_MODULE;
cdev->ops = &sg_fops;
sdp = sg_alloc(disk, scsidp);
sdp = sg_alloc(scsidp);
if (IS_ERR(sdp)) {
pr_warn("%s: sg_alloc failed\n", __func__);
error = PTR_ERR(sdp);
@ -1561,7 +1549,7 @@ sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
MKDEV(SCSI_GENERIC_MAJOR,
sdp->index),
sdp, "%s", disk->disk_name);
sdp, "%s", sdp->name);
if (IS_ERR(sg_class_member)) {
pr_err("%s: device_create failed\n", __func__);
error = PTR_ERR(sg_class_member);
@ -1589,7 +1577,6 @@ cdev_add_err:
kfree(sdp);
out:
put_disk(disk);
if (cdev)
cdev_del(cdev);
return error;
@ -1613,7 +1600,6 @@ sg_device_destroy(struct kref *kref)
SCSI_LOG_TIMEOUT(3,
sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
put_disk(sdp->disk);
kfree(sdp);
}
@ -2606,7 +2592,7 @@ static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
goto skip;
read_lock(&sdp->sfd_lock);
if (!list_empty(&sdp->sfds)) {
seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
seq_printf(s, " >>> device=%s ", sdp->name);
if (atomic_read(&sdp->detaching))
seq_puts(s, "detaching pending close ");
else if (sdp->device) {