linux/block/bsg.c
Linus Torvalds ca7ce08d6a SCSI misc on 20230629
Updates to the usual drivers (ufs, pm80xx, libata-scsi, smartpqi,
 lpfc, qla2xxx).  We have a couple of major core changes impacting
 other systems: Command Duration Limits, which spills into block and
 ATA and block level Persistent Reservation Operations, which touches
 block, nvme, target and dm (both of which are added with merge commits
 containing a cover letter explaining what's going on).
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "Updates to the usual drivers (ufs, pm80xx, libata-scsi, smartpqi,
  lpfc, qla2xxx).

  We have a couple of major core changes impacting other systems:

   - Command Duration Limits, which spills into block and ATA

   - block level Persistent Reservation Operations, which touches block,
     nvme, target and dm

  Both of these are added with merge commits containing a cover letter
  explaining what's going on"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (187 commits)
  scsi: core: Improve warning message in scsi_device_block()
  scsi: core: Replace scsi_target_block() with scsi_block_targets()
  scsi: core: Don't wait for quiesce in scsi_device_block()
  scsi: core: Don't wait for quiesce in scsi_stop_queue()
  scsi: core: Merge scsi_internal_device_block() and device_block()
  scsi: sg: Increase number of devices
  scsi: bsg: Increase number of devices
  scsi: qla2xxx: Remove unused nvme_ls_waitq wait queue
  scsi: ufs: ufs-pci: Add support for Intel Arrow Lake
  scsi: sd: sd_zbc: Use PAGE_SECTORS_SHIFT
  scsi: ufs: wb: Add explicit flush_threshold sysfs attribute
  scsi: ufs: ufs-qcom: Switch to the new ICE API
  scsi: ufs: dt-bindings: qcom: Add ICE phandle
  scsi: ufs: ufs-mediatek: Set UFSHCD_QUIRK_MCQ_BROKEN_RTC quirk
  scsi: ufs: ufs-mediatek: Set UFSHCD_QUIRK_MCQ_BROKEN_INTR quirk
  scsi: ufs: core: Add host quirk UFSHCD_QUIRK_MCQ_BROKEN_RTC
  scsi: ufs: core: Add host quirk UFSHCD_QUIRK_MCQ_BROKEN_INTR
  scsi: ufs: core: Remove dedicated hwq for dev command
  scsi: ufs: core: mcq: Fix the incorrect OCS value for the device command
  scsi: ufs: dt-bindings: samsung,exynos: Drop unneeded quotes
  ...
2023-06-30 11:57:07 -07:00

277 lines
6.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* bsg.c - block layer implementation of the sg v4 interface
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/file.h>
#include <linux/blkdev.h>
#include <linux/cdev.h>
#include <linux/jiffies.h>
#include <linux/percpu.h>
#include <linux/idr.h>
#include <linux/bsg.h>
#include <linux/slab.h>
#include <scsi/scsi.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/sg.h>
#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
#define BSG_VERSION "0.4"
struct bsg_device {
struct request_queue *queue;
struct device device;
struct cdev cdev;
int max_queue;
unsigned int timeout;
unsigned int reserved_size;
bsg_sg_io_fn *sg_io_fn;
};
static inline struct bsg_device *to_bsg_device(struct inode *inode)
{
return container_of(inode->i_cdev, struct bsg_device, cdev);
}
#define BSG_DEFAULT_CMDS 64
#define BSG_MAX_DEVS (1 << MINORBITS)
static DEFINE_IDA(bsg_minor_ida);
static const struct class bsg_class;
static int bsg_major;
static unsigned int bsg_timeout(struct bsg_device *bd, struct sg_io_v4 *hdr)
{
unsigned int timeout = BLK_DEFAULT_SG_TIMEOUT;
if (hdr->timeout)
timeout = msecs_to_jiffies(hdr->timeout);
else if (bd->timeout)
timeout = bd->timeout;
return max_t(unsigned int, timeout, BLK_MIN_SG_TIMEOUT);
}
static int bsg_sg_io(struct bsg_device *bd, bool open_for_write,
void __user *uarg)
{
struct sg_io_v4 hdr;
int ret;
if (copy_from_user(&hdr, uarg, sizeof(hdr)))
return -EFAULT;
if (hdr.guard != 'Q')
return -EINVAL;
ret = bd->sg_io_fn(bd->queue, &hdr, open_for_write,
bsg_timeout(bd, &hdr));
if (!ret && copy_to_user(uarg, &hdr, sizeof(hdr)))
return -EFAULT;
return ret;
}
static int bsg_open(struct inode *inode, struct file *file)
{
if (!blk_get_queue(to_bsg_device(inode)->queue))
return -ENXIO;
return 0;
}
static int bsg_release(struct inode *inode, struct file *file)
{
blk_put_queue(to_bsg_device(inode)->queue);
return 0;
}
static int bsg_get_command_q(struct bsg_device *bd, int __user *uarg)
{
return put_user(READ_ONCE(bd->max_queue), uarg);
}
static int bsg_set_command_q(struct bsg_device *bd, int __user *uarg)
{
int max_queue;
if (get_user(max_queue, uarg))
return -EFAULT;
if (max_queue < 1)
return -EINVAL;
WRITE_ONCE(bd->max_queue, max_queue);
return 0;
}
static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct bsg_device *bd = to_bsg_device(file_inode(file));
struct request_queue *q = bd->queue;
void __user *uarg = (void __user *) arg;
int __user *intp = uarg;
int val;
switch (cmd) {
/*
* Our own ioctls
*/
case SG_GET_COMMAND_Q:
return bsg_get_command_q(bd, uarg);
case SG_SET_COMMAND_Q:
return bsg_set_command_q(bd, uarg);
/*
* SCSI/sg ioctls
*/
case SG_GET_VERSION_NUM:
return put_user(30527, intp);
case SCSI_IOCTL_GET_IDLUN:
return put_user(0, intp);
case SCSI_IOCTL_GET_BUS_NUMBER:
return put_user(0, intp);
case SG_SET_TIMEOUT:
if (get_user(val, intp))
return -EFAULT;
bd->timeout = clock_t_to_jiffies(val);
return 0;
case SG_GET_TIMEOUT:
return jiffies_to_clock_t(bd->timeout);
case SG_GET_RESERVED_SIZE:
return put_user(min(bd->reserved_size, queue_max_bytes(q)),
intp);
case SG_SET_RESERVED_SIZE:
if (get_user(val, intp))
return -EFAULT;
if (val < 0)
return -EINVAL;
bd->reserved_size =
min_t(unsigned int, val, queue_max_bytes(q));
return 0;
case SG_EMULATED_HOST:
return put_user(1, intp);
case SG_IO:
return bsg_sg_io(bd, file->f_mode & FMODE_WRITE, uarg);
case SCSI_IOCTL_SEND_COMMAND:
pr_warn_ratelimited("%s: calling unsupported SCSI_IOCTL_SEND_COMMAND\n",
current->comm);
return -EINVAL;
default:
return -ENOTTY;
}
}
static const struct file_operations bsg_fops = {
.open = bsg_open,
.release = bsg_release,
.unlocked_ioctl = bsg_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.owner = THIS_MODULE,
.llseek = default_llseek,
};
static void bsg_device_release(struct device *dev)
{
struct bsg_device *bd = container_of(dev, struct bsg_device, device);
ida_free(&bsg_minor_ida, MINOR(bd->device.devt));
kfree(bd);
}
void bsg_unregister_queue(struct bsg_device *bd)
{
struct gendisk *disk = bd->queue->disk;
if (disk && disk->queue_kobj.sd)
sysfs_remove_link(&disk->queue_kobj, "bsg");
cdev_device_del(&bd->cdev, &bd->device);
put_device(&bd->device);
}
EXPORT_SYMBOL_GPL(bsg_unregister_queue);
struct bsg_device *bsg_register_queue(struct request_queue *q,
struct device *parent, const char *name, bsg_sg_io_fn *sg_io_fn)
{
struct bsg_device *bd;
int ret;
bd = kzalloc(sizeof(*bd), GFP_KERNEL);
if (!bd)
return ERR_PTR(-ENOMEM);
bd->max_queue = BSG_DEFAULT_CMDS;
bd->reserved_size = INT_MAX;
bd->queue = q;
bd->sg_io_fn = sg_io_fn;
ret = ida_alloc_max(&bsg_minor_ida, BSG_MAX_DEVS - 1, GFP_KERNEL);
if (ret < 0) {
if (ret == -ENOSPC)
dev_err(parent, "bsg: too many bsg devices\n");
kfree(bd);
return ERR_PTR(ret);
}
bd->device.devt = MKDEV(bsg_major, ret);
bd->device.class = &bsg_class;
bd->device.parent = parent;
bd->device.release = bsg_device_release;
dev_set_name(&bd->device, "%s", name);
device_initialize(&bd->device);
cdev_init(&bd->cdev, &bsg_fops);
bd->cdev.owner = THIS_MODULE;
ret = cdev_device_add(&bd->cdev, &bd->device);
if (ret)
goto out_put_device;
if (q->disk && q->disk->queue_kobj.sd) {
ret = sysfs_create_link(&q->disk->queue_kobj, &bd->device.kobj,
"bsg");
if (ret)
goto out_device_del;
}
return bd;
out_device_del:
cdev_device_del(&bd->cdev, &bd->device);
out_put_device:
put_device(&bd->device);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(bsg_register_queue);
static char *bsg_devnode(const struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
}
static const struct class bsg_class = {
.name = "bsg",
.devnode = bsg_devnode,
};
static int __init bsg_init(void)
{
dev_t devid;
int ret;
ret = class_register(&bsg_class);
if (ret)
return ret;
ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
if (ret)
goto destroy_bsg_class;
bsg_major = MAJOR(devid);
printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
" loaded (major %d)\n", bsg_major);
return 0;
destroy_bsg_class:
class_unregister(&bsg_class);
return ret;
}
MODULE_AUTHOR("Jens Axboe");
MODULE_DESCRIPTION(BSG_DESCRIPTION);
MODULE_LICENSE("GPL");
device_initcall(bsg_init);