// SPDX-License-Identifier: GPL-2.0
#include <linux/capability.h>
#include <linux/compat.h>
#include <linux/blkdev.h>
#include <linux/export.h>
#include <linux/gfp.h>
#include <linux/blkpg.h>
#include <linux/hdreg.h>
#include <linux/backing-dev.h>
#include <linux/fs.h>
#include <linux/blktrace_api.h>
#include <linux/pr.h>
#include <linux/uaccess.h>
#include <linux/pagemap.h>
#include <linux/io_uring/cmd.h>
#include <linux/blk-integrity.h>
#include <uapi/linux/blkdev.h>
#include "blk.h"
#include "blk-crypto-internal.h"

static int blkpg_do_ioctl(struct block_device *bdev,
                          struct blkpg_partition __user *upart, int op)
{
        struct gendisk *disk = bdev->bd_disk;
        struct blkpg_partition p;
        sector_t start, length, capacity, end;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
        if (copy_from_user(&p, upart, sizeof(struct blkpg_partition)))
                return -EFAULT;
        if (bdev_is_partition(bdev))
                return -EINVAL;

        if (p.pno <= 0)
                return -EINVAL;

        if (op == BLKPG_DEL_PARTITION)
                return bdev_del_partition(disk, p.pno);

        if (p.start < 0 || p.length <= 0 || LLONG_MAX - p.length < p.start)
                return -EINVAL;
        /* Check that the partition is aligned to the block size */
        if (!IS_ALIGNED(p.start | p.length, bdev_logical_block_size(bdev)))
                return -EINVAL;

        start = p.start >> SECTOR_SHIFT;
        length = p.length >> SECTOR_SHIFT;
        capacity = get_capacity(disk);

        if (check_add_overflow(start, length, &end))
                return -EINVAL;

        if (start >= capacity || end > capacity)
                return -EINVAL;

        switch (op) {
        case BLKPG_ADD_PARTITION:
                return bdev_add_partition(disk, p.pno, start, length);
        case BLKPG_RESIZE_PARTITION:
                return bdev_resize_partition(disk, p.pno, start, length);
        default:
                return -EINVAL;
        }
}

static int blkpg_ioctl(struct block_device *bdev,
                       struct blkpg_ioctl_arg __user *arg)
{
        struct blkpg_partition __user *udata;
        int op;

        if (get_user(op, &arg->op) || get_user(udata, &arg->data))
                return -EFAULT;

        return blkpg_do_ioctl(bdev, udata, op);
}

#ifdef CONFIG_COMPAT
struct compat_blkpg_ioctl_arg {
        compat_int_t op;
        compat_int_t flags;
        compat_int_t datalen;
        compat_caddr_t data;
};

static int compat_blkpg_ioctl(struct block_device *bdev,
                              struct compat_blkpg_ioctl_arg __user *arg)
{
        compat_caddr_t udata;
        int op;

        if (get_user(op, &arg->op) || get_user(udata, &arg->data))
                return -EFAULT;

        return blkpg_do_ioctl(bdev, compat_ptr(udata), op);
}
#endif

/*
 * Check that [start, start + len) is a valid range from the block device's
 * perspective, including verifying that it can be correctly translated into
 * logical block addresses.
 */
static int blk_validate_byte_range(struct block_device *bdev,
                                   uint64_t start, uint64_t len)
{
        unsigned int bs_mask = bdev_logical_block_size(bdev) - 1;
        uint64_t end;

        if ((start | len) & bs_mask)
                return -EINVAL;
        if (!len)
                return -EINVAL;
        if (check_add_overflow(start, len, &end) || end > bdev_nr_bytes(bdev))
                return -EINVAL;

        return 0;
}

static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
                unsigned long arg)
{
        uint64_t range[2], start, len;
        struct bio *prev = NULL, *bio;
        sector_t sector, nr_sects;
        struct blk_plug plug;
        int err;

        if (copy_from_user(range, (void __user *)arg, sizeof(range)))
                return -EFAULT;
        start = range[0];
        len = range[1];

        if (!bdev_max_discard_sectors(bdev))
                return -EOPNOTSUPP;

        if (!(mode & BLK_OPEN_WRITE))
                return -EBADF;
        if (bdev_read_only(bdev))
                return -EPERM;
        err = blk_validate_byte_range(bdev, start, len);
        if (err)
                return err;

        inode_lock(bdev->bd_mapping->host);
        filemap_invalidate_lock(bdev->bd_mapping);
        err = truncate_bdev_range(bdev, mode, start, start + len - 1);
        if (err)
                goto fail;

        sector = start >> SECTOR_SHIFT;
        nr_sects = len >> SECTOR_SHIFT;

        blk_start_plug(&plug);
        while (1) {
                if (fatal_signal_pending(current)) {
                        if (prev)
                                bio_await_chain(prev);
                        err = -EINTR;
                        goto out_unplug;
                }
                bio = blk_alloc_discard_bio(bdev, &sector, &nr_sects,
                                GFP_KERNEL);
                if (!bio)
                        break;
                prev = bio_chain_and_submit(prev, bio);
        }
        if (prev) {
                err = submit_bio_wait(prev);
                if (err == -EOPNOTSUPP)
                        err = 0;
                bio_put(prev);
        }
out_unplug:
        blk_finish_plug(&plug);
fail:
        filemap_invalidate_unlock(bdev->bd_mapping);
        inode_unlock(bdev->bd_mapping->host);
        return err;
}

static int blk_ioctl_secure_erase(struct block_device *bdev, blk_mode_t mode,
                void __user *argp)
{
        uint64_t start, len, end;
        uint64_t range[2];
        int err;

        if (!(mode & BLK_OPEN_WRITE))
                return -EBADF;
        if (!bdev_max_secure_erase_sectors(bdev))
                return -EOPNOTSUPP;
        if (copy_from_user(range, argp, sizeof(range)))
                return -EFAULT;

        start = range[0];
        len = range[1];
        if ((start & 511) || (len & 511))
                return -EINVAL;
        if (check_add_overflow(start, len, &end) ||
            end > bdev_nr_bytes(bdev))
                return -EINVAL;

        inode_lock(bdev->bd_mapping->host);
        filemap_invalidate_lock(bdev->bd_mapping);
        err = truncate_bdev_range(bdev, mode, start, end - 1);
        if (!err)
                err = blkdev_issue_secure_erase(bdev, start >> 9, len >> 9,
                                                GFP_KERNEL);
        filemap_invalidate_unlock(bdev->bd_mapping);
        inode_unlock(bdev->bd_mapping->host);
        return err;
}


static int blk_ioctl_zeroout(struct block_device *bdev, blk_mode_t mode,
                unsigned long arg)
{
        uint64_t range[2];
        uint64_t start, end, len;
        int err;

        if (!(mode & BLK_OPEN_WRITE))
                return -EBADF;

        if (copy_from_user(range, (void __user *)arg, sizeof(range)))
                return -EFAULT;

        start = range[0];
        len = range[1];
        end = start + len - 1;

        if (start & 511)
                return -EINVAL;
        if (len & 511)
                return -EINVAL;
        if (end >= (uint64_t)bdev_nr_bytes(bdev))
                return -EINVAL;
        if (end < start)
                return -EINVAL;

        /* Invalidate the page cache, including dirty pages */
        inode_lock(bdev->bd_mapping->host);
        filemap_invalidate_lock(bdev->bd_mapping);
        err = truncate_bdev_range(bdev, mode, start, end);
        if (err)
                goto fail;

        err = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
                                   BLKDEV_ZERO_NOUNMAP | BLKDEV_ZERO_KILLABLE);

fail:
        filemap_invalidate_unlock(bdev->bd_mapping);
        inode_unlock(bdev->bd_mapping->host);
        return err;
}

static int put_ushort(unsigned short __user *argp, unsigned short val)
{
        return put_user(val, argp);
}

static int put_int(int __user *argp, int val)
{
        return put_user(val, argp);
}

static int put_uint(unsigned int __user *argp, unsigned int val)
{
        return put_user(val, argp);
}

static int put_long(long __user *argp, long val)
{
        return put_user(val, argp);
}

static int put_ulong(unsigned long __user *argp, unsigned long val)
{
        return put_user(val, argp);
}

static int put_u64(u64 __user *argp, u64 val)
{
        return put_user(val, argp);
}

#ifdef CONFIG_COMPAT
static int compat_put_long(compat_long_t __user *argp, long val)
{
        return put_user(val, argp);
}

static int compat_put_ulong(compat_ulong_t __user *argp, compat_ulong_t val)
{
        return put_user(val, argp);
}
#endif

#ifdef CONFIG_COMPAT
/*
 * This is the equivalent of compat_ptr_ioctl(), to be used by block
 * drivers that implement only commands that are completely compatible
 * between 32-bit and 64-bit user space
 */
int blkdev_compat_ptr_ioctl(struct block_device *bdev, blk_mode_t mode,
                        unsigned cmd, unsigned long arg)
{
        struct gendisk *disk = bdev->bd_disk;

        if (disk->fops->ioctl)
                return disk->fops->ioctl(bdev, mode, cmd,
                                         (unsigned long)compat_ptr(arg));

        return -ENOIOCTLCMD;
}
EXPORT_SYMBOL(blkdev_compat_ptr_ioctl);
#endif

enum pr_direction {
        PR_IN,  /* read from device */
        PR_OUT, /* write to device */
};

static bool blkdev_pr_allowed(struct block_device *bdev, blk_mode_t mode,
                enum pr_direction dir)
{
        /* no sense to make reservations for partitions */
        if (bdev_is_partition(bdev))
                return false;

        if (capable(CAP_SYS_ADMIN))
                return true;

        /*
         * Only allow unprivileged reservation _out_ commands if the file
         * descriptor is open for writing. Allow reservation _in_ commands if
         * the file descriptor is open for reading since they do not modify the
         * device.
         */
        if (dir == PR_IN)
                return mode & BLK_OPEN_READ;
        else
                return mode & BLK_OPEN_WRITE;
}

static int blkdev_pr_register(struct block_device *bdev, blk_mode_t mode,
                struct pr_registration __user *arg)
{
        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
        struct pr_registration reg;

        if (!blkdev_pr_allowed(bdev, mode, PR_OUT))
                return -EPERM;
        if (!ops || !ops->pr_register)
                return -EOPNOTSUPP;
        if (copy_from_user(&reg, arg, sizeof(reg)))
                return -EFAULT;

        if (reg.flags & ~PR_FL_IGNORE_KEY)
                return -EOPNOTSUPP;
        return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
}

static int blkdev_pr_reserve(struct block_device *bdev, blk_mode_t mode,
                struct pr_reservation __user *arg)
{
        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
        struct pr_reservation rsv;

        if (!blkdev_pr_allowed(bdev, mode, PR_OUT))
                return -EPERM;
        if (!ops || !ops->pr_reserve)
                return -EOPNOTSUPP;
        if (copy_from_user(&rsv, arg, sizeof(rsv)))
                return -EFAULT;

        if (rsv.flags & ~PR_FL_IGNORE_KEY)
                return -EOPNOTSUPP;
        return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
}

static int blkdev_pr_release(struct block_device *bdev, blk_mode_t mode,
                struct pr_reservation __user *arg)
{
        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
        struct pr_reservation rsv;

        if (!blkdev_pr_allowed(bdev, mode, PR_OUT))
                return -EPERM;
        if (!ops || !ops->pr_release)
                return -EOPNOTSUPP;
        if (copy_from_user(&rsv, arg, sizeof(rsv)))
                return -EFAULT;

        if (rsv.flags)
                return -EOPNOTSUPP;
        return ops->pr_release(bdev, rsv.key, rsv.type);
}

static int blkdev_pr_preempt(struct block_device *bdev, blk_mode_t mode,
                struct pr_preempt __user *arg, bool abort)
{
        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
        struct pr_preempt p;

        if (!blkdev_pr_allowed(bdev, mode, PR_OUT))
                return -EPERM;
        if (!ops || !ops->pr_preempt)
                return -EOPNOTSUPP;
        if (copy_from_user(&p, arg, sizeof(p)))
                return -EFAULT;

        if (p.flags)
                return -EOPNOTSUPP;
        return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
}

static int blkdev_pr_clear(struct block_device *bdev, blk_mode_t mode,
                struct pr_clear __user *arg)
{
        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
        struct pr_clear c;

        if (!blkdev_pr_allowed(bdev, mode, PR_OUT))
                return -EPERM;
        if (!ops || !ops->pr_clear)
                return -EOPNOTSUPP;
        if (copy_from_user(&c, arg, sizeof(c)))
                return -EFAULT;

        if (c.flags)
                return -EOPNOTSUPP;
        return ops->pr_clear(bdev, c.key);
}

static int blkdev_pr_read_keys(struct block_device *bdev, blk_mode_t mode,
                struct pr_read_keys __user *arg)
{
        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
        struct pr_keys *keys_info;
        struct pr_read_keys read_keys;
        u64 __user *keys_ptr;
        size_t keys_info_len;
        size_t keys_copy_len;
        int ret;

        if (!blkdev_pr_allowed(bdev, mode, PR_IN))
                return -EPERM;
        if (!ops || !ops->pr_read_keys)
                return -EOPNOTSUPP;

        if (copy_from_user(&read_keys, arg, sizeof(read_keys)))
                return -EFAULT;

        if (read_keys.num_keys > PR_KEYS_MAX)
                return -EINVAL;

        keys_info_len = struct_size(keys_info, keys, read_keys.num_keys);

        keys_info = kvzalloc(keys_info_len, GFP_KERNEL);
        if (!keys_info)
                return -ENOMEM;

        keys_info->num_keys = read_keys.num_keys;

        ret = ops->pr_read_keys(bdev, keys_info);
        if (ret)
                goto out;

        /* Copy out individual keys */
        keys_ptr = u64_to_user_ptr(read_keys.keys_ptr);
        keys_copy_len = min(read_keys.num_keys, keys_info->num_keys) *
                        sizeof(keys_info->keys[0]);

        if (copy_to_user(keys_ptr, keys_info->keys, keys_copy_len)) {
                ret = -EFAULT;
                goto out;
        }

        /* Copy out the arg struct */
        read_keys.generation = keys_info->generation;
        read_keys.num_keys = keys_info->num_keys;

        if (copy_to_user(arg, &read_keys, sizeof(read_keys)))
                ret = -EFAULT;
out:
        kvfree(keys_info);
        return ret;
}

static int blkdev_pr_read_reservation(struct block_device *bdev,
                blk_mode_t mode, struct pr_read_reservation __user *arg)
{
        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
        struct pr_held_reservation rsv = {};
        struct pr_read_reservation out = {};
        int ret;

        if (!blkdev_pr_allowed(bdev, mode, PR_IN))
                return -EPERM;
        if (!ops || !ops->pr_read_reservation)
                return -EOPNOTSUPP;

        ret = ops->pr_read_reservation(bdev, &rsv);
        if (ret)
                return ret;

        out.key = rsv.key;
        out.generation = rsv.generation;
        out.type = rsv.type;

        if (copy_to_user(arg, &out, sizeof(out)))
                return -EFAULT;
        return 0;
}

static int blkdev_flushbuf(struct block_device *bdev, unsigned cmd,
                unsigned long arg)
{
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;

        mutex_lock(&bdev->bd_holder_lock);
        if (bdev->bd_holder_ops && bdev->bd_holder_ops->sync)
                bdev->bd_holder_ops->sync(bdev);
        else {
                mutex_unlock(&bdev->bd_holder_lock);
                sync_blockdev(bdev);
        }

        invalidate_bdev(bdev);
        return 0;
}

static int blkdev_roset(struct block_device *bdev, unsigned cmd,
                unsigned long arg)
{
        int ret, n;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;

        if (get_user(n, (int __user *)arg))
                return -EFAULT;
        if (bdev->bd_disk->fops->set_read_only) {
                ret = bdev->bd_disk->fops->set_read_only(bdev, n);
                if (ret)
                        return ret;
        }
        if (n)
                bdev_set_flag(bdev, BD_READ_ONLY);
        else
                bdev_clear_flag(bdev, BD_READ_ONLY);
        return 0;
}

static int blkdev_getgeo(struct block_device *bdev,
                struct hd_geometry __user *argp)
{
        struct gendisk *disk = bdev->bd_disk;
        struct hd_geometry geo;
        int ret;

        if (!argp)
                return -EINVAL;
        if (!disk->fops->getgeo)
                return -ENOTTY;

        /*
         * We need to set the startsect first, the driver may
         * want to override it.
         */
        memset(&geo, 0, sizeof(geo));
        geo.start = get_start_sect(bdev);
        ret = disk->fops->getgeo(disk, &geo);
        if (ret)
                return ret;
        if (copy_to_user(argp, &geo, sizeof(geo)))
                return -EFAULT;
        return 0;
}

#ifdef CONFIG_COMPAT
struct compat_hd_geometry {
        unsigned char heads;
        unsigned char sectors;
        unsigned short cylinders;
        u32 start;
};

static int compat_hdio_getgeo(struct block_device *bdev,
                              struct compat_hd_geometry __user *ugeo)
{
        struct gendisk *disk = bdev->bd_disk;
        struct hd_geometry geo;
        int ret;

        if (!ugeo)
                return -EINVAL;
        if (!disk->fops->getgeo)
                return -ENOTTY;

        memset(&geo, 0, sizeof(geo));
        /*
         * We need to set the startsect first, the driver may
         * want to override it.
         */
        geo.start = get_start_sect(bdev);
        ret = disk->fops->getgeo(disk, &geo);
        if (ret)
                return ret;

        ret = copy_to_user(ugeo, &geo, 4);
        ret |= put_user(geo.start, &ugeo->start);
        if (ret)
                ret = -EFAULT;

        return ret;
}
#endif

/* set the logical block size */
static int blkdev_bszset(struct file *file, blk_mode_t mode,
                int __user *argp)
{
        // this one might be file_inode(file)->i_rdev - a rare valid
        // use of file_inode() for those.
        dev_t dev = I_BDEV(file->f_mapping->host)->bd_dev;
        struct file *excl_file;
        int ret, n;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
        if (!argp)
                return -EINVAL;
        if (get_user(n, argp))
                return -EFAULT;

        if (mode & BLK_OPEN_EXCL)
                return set_blocksize(file, n);

        excl_file = bdev_file_open_by_dev(dev, mode, &dev, NULL);
        if (IS_ERR(excl_file))
                return -EBUSY;
        ret = set_blocksize(excl_file, n);
        fput(excl_file);
        return ret;
}

/*
 * Common commands that are handled the same way on native and compat
 * user space. Note the separate arg/argp parameters that are needed
 * to deal with the compat_ptr() conversion.
 */
static int blkdev_common_ioctl(struct block_device *bdev, blk_mode_t mode,
                               unsigned int cmd, unsigned long arg,
                               void __user *argp)
{
        unsigned int max_sectors;

        switch (cmd) {
        case BLKFLSBUF:
                return blkdev_flushbuf(bdev, cmd, arg);
        case BLKROSET:
                return blkdev_roset(bdev, cmd, arg);
        case BLKDISCARD:
                return blk_ioctl_discard(bdev, mode, arg);
        case BLKSECDISCARD:
                return blk_ioctl_secure_erase(bdev, mode, argp);
        case BLKZEROOUT:
                return blk_ioctl_zeroout(bdev, mode, arg);
        case BLKGETDISKSEQ:
                return put_u64(argp, bdev->bd_disk->diskseq);
        case BLKREPORTZONE:
        case BLKREPORTZONEV2:
                return blkdev_report_zones_ioctl(bdev, cmd, arg);
        case BLKRESETZONE:
        case BLKOPENZONE:
        case BLKCLOSEZONE:
        case BLKFINISHZONE:
                return blkdev_zone_mgmt_ioctl(bdev, mode, cmd, arg);
        case BLKGETZONESZ:
                return put_uint(argp, bdev_zone_sectors(bdev));
        case BLKGETNRZONES:
                return put_uint(argp, bdev_nr_zones(bdev));
        case BLKROGET:
                return put_int(argp, bdev_read_only(bdev) != 0);
        case BLKSSZGET: /* get block device logical block size */
                return put_int(argp, bdev_logical_block_size(bdev));
        case BLKPBSZGET: /* get block device physical block size */
                return put_uint(argp, bdev_physical_block_size(bdev));
        case BLKIOMIN:
                return put_uint(argp, bdev_io_min(bdev));
        case BLKIOOPT:
                return put_uint(argp, bdev_io_opt(bdev));
        case BLKALIGNOFF:
                return put_int(argp, bdev_alignment_offset(bdev));
        case BLKDISCARDZEROES:
                return put_uint(argp, 0);
        case BLKSECTGET:
                max_sectors = min_t(unsigned int, USHRT_MAX,
                                    queue_max_sectors(bdev_get_queue(bdev)));
                return put_ushort(argp, max_sectors);
        case BLKROTATIONAL:
                return put_ushort(argp, bdev_rot(bdev));
        case BLKRASET:
        case BLKFRASET:
                if(!capable(CAP_SYS_ADMIN))
                        return -EACCES;
                bdev->bd_disk->bdi->ra_pages = (arg * 512) / PAGE_SIZE;
                return 0;
        case BLKRRPART:
                if (!capable(CAP_SYS_ADMIN))
                        return -EACCES;
                if (bdev_is_partition(bdev))
                        return -EINVAL;
                return disk_scan_partitions(bdev->bd_disk,
                                mode | BLK_OPEN_STRICT_SCAN);
        case BLKTRACESTART:
        case BLKTRACESTOP:
        case BLKTRACETEARDOWN:
                return blk_trace_ioctl(bdev, cmd, argp);
        case BLKCRYPTOIMPORTKEY:
        case BLKCRYPTOGENERATEKEY:
        case BLKCRYPTOPREPAREKEY:
                return blk_crypto_ioctl(bdev, cmd, argp);
        case IOC_PR_REGISTER:
                return blkdev_pr_register(bdev, mode, argp);
        case IOC_PR_RESERVE:
                return blkdev_pr_reserve(bdev, mode, argp);
        case IOC_PR_RELEASE:
                return blkdev_pr_release(bdev, mode, argp);
        case IOC_PR_PREEMPT:
                return blkdev_pr_preempt(bdev, mode, argp, false);
        case IOC_PR_PREEMPT_ABORT:
                return blkdev_pr_preempt(bdev, mode, argp, true);
        case IOC_PR_CLEAR:
                return blkdev_pr_clear(bdev, mode, argp);
        case IOC_PR_READ_KEYS:
                return blkdev_pr_read_keys(bdev, mode, argp);
        case IOC_PR_READ_RESERVATION:
                return blkdev_pr_read_reservation(bdev, mode, argp);
        default:
                return blk_get_meta_cap(bdev, cmd, argp);
        }
}

/*
 * Always keep this in sync with compat_blkdev_ioctl()
 * to handle all incompatible commands in both functions.
 *
 * New commands must be compatible and go into blkdev_common_ioctl
 */
long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
{
        struct block_device *bdev = I_BDEV(file->f_mapping->host);
        void __user *argp = (void __user *)arg;
        blk_mode_t mode = file_to_blk_mode(file);
        int ret;

        switch (cmd) {
        /* These need separate implementations for the data structure */
        case HDIO_GETGEO:
                return blkdev_getgeo(bdev, argp);
        case BLKPG:
                return blkpg_ioctl(bdev, argp);

        /* Compat mode returns 32-bit data instead of 'long' */
        case BLKRAGET:
        case BLKFRAGET:
                if (!argp)
                        return -EINVAL;
                return put_long(argp,
                        (bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512);
        case BLKGETSIZE:
                if (bdev_nr_sectors(bdev) > ~0UL)
                        return -EFBIG;
                return put_ulong(argp, bdev_nr_sectors(bdev));

        /* The data is compatible, but the command number is different */
        case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
                return put_int(argp, block_size(bdev));
        case BLKBSZSET:
                return blkdev_bszset(file, mode, argp);
        case BLKGETSIZE64:
                return put_u64(argp, bdev_nr_bytes(bdev));

        /* Incompatible alignment on i386 */
        case BLKTRACESETUP:
        case BLKTRACESETUP2:
                return blk_trace_ioctl(bdev, cmd, argp);
        default:
                break;
        }

        ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
        if (ret != -ENOIOCTLCMD)
                return ret;

        if (!bdev->bd_disk->fops->ioctl)
                return -ENOTTY;
        return bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
}

#ifdef CONFIG_COMPAT

#define BLKBSZGET_32            _IOR(0x12, 112, int)
#define BLKBSZSET_32            _IOW(0x12, 113, int)
#define BLKGETSIZE64_32         _IOR(0x12, 114, int)

/* Most of the generic ioctls are handled in the normal fallback path.
   This assumes the blkdev's low level compat_ioctl always returns
   ENOIOCTLCMD for unknown ioctls. */
long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
{
        int ret;
        void __user *argp = compat_ptr(arg);
        struct block_device *bdev = I_BDEV(file->f_mapping->host);
        struct gendisk *disk = bdev->bd_disk;
        blk_mode_t mode = file_to_blk_mode(file);

        switch (cmd) {
        /* These need separate implementations for the data structure */
        case HDIO_GETGEO:
                return compat_hdio_getgeo(bdev, argp);
        case BLKPG:
                return compat_blkpg_ioctl(bdev, argp);

        /* Compat mode returns 32-bit data instead of 'long' */
        case BLKRAGET:
        case BLKFRAGET:
                if (!argp)
                        return -EINVAL;
                return compat_put_long(argp,
                        (bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512);
        case BLKGETSIZE:
                if (bdev_nr_sectors(bdev) > ~(compat_ulong_t)0)
                        return -EFBIG;
                return compat_put_ulong(argp, bdev_nr_sectors(bdev));

        /* The data is compatible, but the command number is different */
        case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
                return put_int(argp, bdev_logical_block_size(bdev));
        case BLKBSZSET_32:
                return blkdev_bszset(file, mode, argp);
        case BLKGETSIZE64_32:
                return put_u64(argp, bdev_nr_bytes(bdev));

        /* Incompatible alignment on i386 */
        case BLKTRACESETUP32:
                return blk_trace_ioctl(bdev, cmd, argp);
        default:
                break;
        }

        ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
        if (ret == -ENOIOCTLCMD && disk->fops->compat_ioctl)
                ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);

        return ret;
}
#endif

struct blk_iou_cmd {
        int res;
        bool nowait;
};

static void blk_cmd_complete(struct io_tw_req tw_req, io_tw_token_t tw)
{
        struct io_uring_cmd *cmd = io_uring_cmd_from_tw(tw_req);
        struct blk_iou_cmd *bic = io_uring_cmd_to_pdu(cmd, struct blk_iou_cmd);

        if (bic->res == -EAGAIN && bic->nowait)
                io_uring_cmd_issue_blocking(cmd);
        else
                io_uring_cmd_done(cmd, bic->res,
                                  IO_URING_CMD_TASK_WORK_ISSUE_FLAGS);
}

static void bio_cmd_bio_end_io(struct bio *bio)
{
        struct io_uring_cmd *cmd = bio->bi_private;
        struct blk_iou_cmd *bic = io_uring_cmd_to_pdu(cmd, struct blk_iou_cmd);

        if (unlikely(bio->bi_status) && !bic->res)
                bic->res = blk_status_to_errno(bio->bi_status);

        io_uring_cmd_do_in_task_lazy(cmd, blk_cmd_complete);
        bio_put(bio);
}

static int blkdev_cmd_discard(struct io_uring_cmd *cmd,
                              struct block_device *bdev,
                              uint64_t start, uint64_t len, bool nowait)
{
        struct blk_iou_cmd *bic = io_uring_cmd_to_pdu(cmd, struct blk_iou_cmd);
        gfp_t gfp = nowait ? GFP_NOWAIT : GFP_KERNEL;
        sector_t sector = start >> SECTOR_SHIFT;
        sector_t nr_sects = len >> SECTOR_SHIFT;
        struct bio *prev = NULL, *bio;
        int err;

        if (!bdev_max_discard_sectors(bdev))
                return -EOPNOTSUPP;
        if (!(file_to_blk_mode(cmd->file) & BLK_OPEN_WRITE))
                return -EBADF;
        if (bdev_read_only(bdev))
                return -EPERM;
        err = blk_validate_byte_range(bdev, start, len);
        if (err)
                return err;

        err = filemap_invalidate_pages(bdev->bd_mapping, start,
                                        start + len - 1, nowait);
        if (err)
                return err;

        while (true) {
                bio = blk_alloc_discard_bio(bdev, &sector, &nr_sects, gfp);
                if (!bio)
                        break;
                if (nowait) {
                        /*
                         * Don't allow multi-bio non-blocking submissions as
                         * subsequent bios may fail but we won't get a direct
                         * indication of that. Normally, the caller should
                         * retry from a blocking context.
                         */
                        if (unlikely(nr_sects)) {
                                bio_put(bio);
                                return -EAGAIN;
                        }
                        bio->bi_opf |= REQ_NOWAIT;
                }

                prev = bio_chain_and_submit(prev, bio);
        }
        if (unlikely(!prev))
                return -EAGAIN;
        if (unlikely(nr_sects))
                bic->res = -EAGAIN;

        prev->bi_private = cmd;
        prev->bi_end_io = bio_cmd_bio_end_io;
        submit_bio(prev);
        return -EIOCBQUEUED;
}

int blkdev_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
{
        struct block_device *bdev = I_BDEV(cmd->file->f_mapping->host);
        struct blk_iou_cmd *bic = io_uring_cmd_to_pdu(cmd, struct blk_iou_cmd);
        const struct io_uring_sqe *sqe = cmd->sqe;
        u32 cmd_op = cmd->cmd_op;
        uint64_t start, len;

        if (unlikely(sqe->ioprio || sqe->__pad1 || sqe->len ||
                     sqe->rw_flags || sqe->file_index))
                return -EINVAL;

        bic->res = 0;
        bic->nowait = issue_flags & IO_URING_F_NONBLOCK;

        start = READ_ONCE(sqe->addr);
        len = READ_ONCE(sqe->addr3);

        switch (cmd_op) {
        case BLOCK_URING_CMD_DISCARD:
                return blkdev_cmd_discard(cmd, bdev, start, len, bic->nowait);
        }
        return -EINVAL;
}