kernel_optimize_test/block/ioctl.c
Jan Kara 384d87ef2c block: Do not discard buffers under a mounted filesystem
Discarding blocks and buffers under a mounted filesystem is hardly
anything admin wants to do. Usually it will confuse the filesystem and
sometimes the loss of buffer_head state (including b_private field) can
even cause crashes like:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 0 P4D 0
Oops: 0002 [#1] SMP PTI
CPU: 4 PID: 203778 Comm: jbd2/dm-3-8 Kdump: loaded Tainted: G O     --------- -  - 4.18.0-147.5.0.5.h126.eulerosv2r9.x86_64 #1
Hardware name: Huawei RH2288H V3/BC11HGSA0, BIOS 1.57 08/11/2015
RIP: 0010:jbd2_journal_grab_journal_head+0x1b/0x40 [jbd2]
...
Call Trace:
 __jbd2_journal_insert_checkpoint+0x23/0x70 [jbd2]
 jbd2_journal_commit_transaction+0x155f/0x1b60 [jbd2]
 kjournald2+0xbd/0x270 [jbd2]

So if we don't have block device open with O_EXCL already, claim the
block device while we truncate buffer cache. This makes sure any
exclusive block device user (such as filesystem) cannot operate on the
device while we are discarding buffer cache.

Reported-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[axboe: fix !CONFIG_BLOCK error in truncate_bdev_range()]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-07 20:10:55 -06:00

700 lines
17 KiB
C

// 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 "blk.h"
static int blkpg_do_ioctl(struct block_device *bdev,
struct blkpg_partition __user *upart, int op)
{
struct blkpg_partition p;
long long start, length;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (copy_from_user(&p, upart, sizeof(struct blkpg_partition)))
return -EFAULT;
if (bdev != bdev->bd_contains)
return -EINVAL;
if (p.pno <= 0)
return -EINVAL;
if (op == BLKPG_DEL_PARTITION)
return bdev_del_partition(bdev, p.pno);
start = p.start >> SECTOR_SHIFT;
length = p.length >> SECTOR_SHIFT;
/* check for fit in a hd_struct */
if (sizeof(sector_t) < sizeof(long long)) {
long pstart = start, plength = length;
if (pstart != start || plength != length || pstart < 0 ||
plength < 0 || p.pno > 65535)
return -EINVAL;
}
switch (op) {
case BLKPG_ADD_PARTITION:
/* check if partition is aligned to blocksize */
if (p.start & (bdev_logical_block_size(bdev) - 1))
return -EINVAL;
return bdev_add_partition(bdev, p.pno, start, length);
case BLKPG_RESIZE_PARTITION:
return bdev_resize_partition(bdev, 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
static int blkdev_reread_part(struct block_device *bdev)
{
int ret;
if (!disk_part_scan_enabled(bdev->bd_disk) || bdev != bdev->bd_contains)
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
mutex_lock(&bdev->bd_mutex);
ret = bdev_disk_changed(bdev, false);
mutex_unlock(&bdev->bd_mutex);
return ret;
}
static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
unsigned long arg, unsigned long flags)
{
uint64_t range[2];
uint64_t start, len;
struct request_queue *q = bdev_get_queue(bdev);
int err;
if (!(mode & FMODE_WRITE))
return -EBADF;
if (!blk_queue_discard(q))
return -EOPNOTSUPP;
if (copy_from_user(range, (void __user *)arg, sizeof(range)))
return -EFAULT;
start = range[0];
len = range[1];
if (start & 511)
return -EINVAL;
if (len & 511)
return -EINVAL;
if (start + len > i_size_read(bdev->bd_inode))
return -EINVAL;
err = truncate_bdev_range(bdev, mode, start, start + len - 1);
if (err)
return err;
return blkdev_issue_discard(bdev, start >> 9, len >> 9,
GFP_KERNEL, flags);
}
static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
unsigned long arg)
{
uint64_t range[2];
uint64_t start, end, len;
int err;
if (!(mode & FMODE_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)i_size_read(bdev->bd_inode))
return -EINVAL;
if (end < start)
return -EINVAL;
/* Invalidate the page cache, including dirty pages */
err = truncate_bdev_range(bdev, mode, start, end);
if (err)
return err;
return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
BLKDEV_ZERO_NOUNMAP);
}
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
int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
unsigned cmd, unsigned long arg)
{
struct gendisk *disk = bdev->bd_disk;
if (disk->fops->ioctl)
return disk->fops->ioctl(bdev, mode, cmd, arg);
return -ENOTTY;
}
/*
* For the record: _GPL here is only because somebody decided to slap it
* on the previous export. Sheer idiocy, since it wasn't copyrightable
* at all and could be open-coded without any exports by anybody who cares.
*/
EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
#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, fmode_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
static int blkdev_pr_register(struct block_device *bdev,
struct pr_registration __user *arg)
{
const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
struct pr_registration reg;
if (!capable(CAP_SYS_ADMIN))
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,
struct pr_reservation __user *arg)
{
const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
struct pr_reservation rsv;
if (!capable(CAP_SYS_ADMIN))
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,
struct pr_reservation __user *arg)
{
const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
struct pr_reservation rsv;
if (!capable(CAP_SYS_ADMIN))
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,
struct pr_preempt __user *arg, bool abort)
{
const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
struct pr_preempt p;
if (!capable(CAP_SYS_ADMIN))
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,
struct pr_clear __user *arg)
{
const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
struct pr_clear c;
if (!capable(CAP_SYS_ADMIN))
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);
}
/*
* Is it an unrecognized ioctl? The correct returns are either
* ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
* fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
* code before returning.
*
* Confused drivers sometimes return EINVAL, which is wrong. It
* means "I understood the ioctl command, but the parameters to
* it were wrong".
*
* We should aim to just fix the broken drivers, the EINVAL case
* should go away.
*/
static inline int is_unrecognized_ioctl(int ret)
{
return ret == -EINVAL ||
ret == -ENOTTY ||
ret == -ENOIOCTLCMD;
}
static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
unsigned cmd, unsigned long arg)
{
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
if (!is_unrecognized_ioctl(ret))
return ret;
fsync_bdev(bdev);
invalidate_bdev(bdev);
return 0;
}
static int blkdev_roset(struct block_device *bdev, fmode_t mode,
unsigned cmd, unsigned long arg)
{
int ret, n;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
if (!is_unrecognized_ioctl(ret))
return ret;
if (get_user(n, (int __user *)arg))
return -EFAULT;
set_device_ro(bdev, n);
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(bdev, &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(bdev, &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 block_device *bdev, fmode_t mode,
int __user *argp)
{
int ret, n;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (!argp)
return -EINVAL;
if (get_user(n, argp))
return -EFAULT;
if (!(mode & FMODE_EXCL)) {
bdgrab(bdev);
if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
return -EBUSY;
}
ret = set_blocksize(bdev, n);
if (!(mode & FMODE_EXCL))
blkdev_put(bdev, mode | FMODE_EXCL);
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, fmode_t mode,
unsigned cmd, unsigned long arg, void __user *argp)
{
unsigned int max_sectors;
switch (cmd) {
case BLKFLSBUF:
return blkdev_flushbuf(bdev, mode, cmd, arg);
case BLKROSET:
return blkdev_roset(bdev, mode, cmd, arg);
case BLKDISCARD:
return blk_ioctl_discard(bdev, mode, arg, 0);
case BLKSECDISCARD:
return blk_ioctl_discard(bdev, mode, arg,
BLKDEV_DISCARD_SECURE);
case BLKZEROOUT:
return blk_ioctl_zeroout(bdev, mode, arg);
case BLKREPORTZONE:
return blkdev_report_zones_ioctl(bdev, mode, 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, blkdev_nr_zones(bdev->bd_disk));
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, !blk_queue_nonrot(bdev_get_queue(bdev)));
case BLKRASET:
case BLKFRASET:
if(!capable(CAP_SYS_ADMIN))
return -EACCES;
bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
return 0;
case BLKRRPART:
return blkdev_reread_part(bdev);
case BLKTRACESTART:
case BLKTRACESTOP:
case BLKTRACETEARDOWN:
return blk_trace_ioctl(bdev, cmd, argp);
case IOC_PR_REGISTER:
return blkdev_pr_register(bdev, argp);
case IOC_PR_RESERVE:
return blkdev_pr_reserve(bdev, argp);
case IOC_PR_RELEASE:
return blkdev_pr_release(bdev, argp);
case IOC_PR_PREEMPT:
return blkdev_pr_preempt(bdev, argp, false);
case IOC_PR_PREEMPT_ABORT:
return blkdev_pr_preempt(bdev, argp, true);
case IOC_PR_CLEAR:
return blkdev_pr_clear(bdev, argp);
default:
return -ENOIOCTLCMD;
}
}
/*
* 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
*/
int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
unsigned long arg)
{
int ret;
loff_t size;
void __user *argp = (void __user *)arg;
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_bdi->ra_pages*PAGE_SIZE) / 512);
case BLKGETSIZE:
size = i_size_read(bdev->bd_inode);
if ((size >> 9) > ~0UL)
return -EFBIG;
return put_ulong(argp, size >> 9);
/* 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(bdev, mode, argp);
case BLKGETSIZE64:
return put_u64(argp, i_size_read(bdev->bd_inode));
/* Incompatible alignment on i386 */
case BLKTRACESETUP:
return blk_trace_ioctl(bdev, cmd, argp);
default:
break;
}
ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
if (ret == -ENOIOCTLCMD)
return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
return ret;
}
EXPORT_SYMBOL_GPL(blkdev_ioctl); /* for /dev/raw */
#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 inode *inode = file->f_mapping->host;
struct block_device *bdev = inode->i_bdev;
struct gendisk *disk = bdev->bd_disk;
fmode_t mode = file->f_mode;
loff_t size;
/*
* O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
* to updated it before every ioctl.
*/
if (file->f_flags & O_NDELAY)
mode |= FMODE_NDELAY;
else
mode &= ~FMODE_NDELAY;
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_bdi->ra_pages * PAGE_SIZE) / 512);
case BLKGETSIZE:
size = i_size_read(bdev->bd_inode);
if ((size >> 9) > ~0UL)
return -EFBIG;
return compat_put_ulong(argp, size >> 9);
/* 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(bdev, mode, argp);
case BLKGETSIZE64_32:
return put_u64(argp, i_size_read(bdev->bd_inode));
/* 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