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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /block/ioctl.c
Initial import
Diffstat (limited to 'block/ioctl.c')
-rw-r--r--block/ioctl.c430
1 files changed, 430 insertions, 0 deletions
diff --git a/block/ioctl.c b/block/ioctl.c
new file mode 100644
index 000000000..7d8befde2
--- /dev/null
+++ b/block/ioctl.c
@@ -0,0 +1,430 @@
+#include <linux/capability.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 <asm/uaccess.h>
+
+static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
+{
+ struct block_device *bdevp;
+ struct gendisk *disk;
+ struct hd_struct *part, *lpart;
+ struct blkpg_ioctl_arg a;
+ struct blkpg_partition p;
+ struct disk_part_iter piter;
+ long long start, length;
+ int partno;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
+ return -EFAULT;
+ if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
+ return -EFAULT;
+ disk = bdev->bd_disk;
+ if (bdev != bdev->bd_contains)
+ return -EINVAL;
+ partno = p.pno;
+ if (partno <= 0)
+ return -EINVAL;
+ switch (a.op) {
+ case BLKPG_ADD_PARTITION:
+ start = p.start >> 9;
+ length = p.length >> 9;
+ /* check for fit in a hd_struct */
+ if (sizeof(sector_t) == sizeof(long) &&
+ sizeof(long long) > sizeof(long)) {
+ long pstart = start, plength = length;
+ if (pstart != start || plength != length
+ || pstart < 0 || plength < 0 || partno > 65535)
+ return -EINVAL;
+ }
+
+ mutex_lock(&bdev->bd_mutex);
+
+ /* overlap? */
+ disk_part_iter_init(&piter, disk,
+ DISK_PITER_INCL_EMPTY);
+ while ((part = disk_part_iter_next(&piter))) {
+ if (!(start + length <= part->start_sect ||
+ start >= part->start_sect + part->nr_sects)) {
+ disk_part_iter_exit(&piter);
+ mutex_unlock(&bdev->bd_mutex);
+ return -EBUSY;
+ }
+ }
+ disk_part_iter_exit(&piter);
+
+ /* all seems OK */
+ part = add_partition(disk, partno, start, length,
+ ADDPART_FLAG_NONE, NULL);
+ mutex_unlock(&bdev->bd_mutex);
+ return PTR_ERR_OR_ZERO(part);
+ case BLKPG_DEL_PARTITION:
+ part = disk_get_part(disk, partno);
+ if (!part)
+ return -ENXIO;
+
+ bdevp = bdget(part_devt(part));
+ disk_put_part(part);
+ if (!bdevp)
+ return -ENOMEM;
+
+ mutex_lock(&bdevp->bd_mutex);
+ if (bdevp->bd_openers) {
+ mutex_unlock(&bdevp->bd_mutex);
+ bdput(bdevp);
+ return -EBUSY;
+ }
+ /* all seems OK */
+ fsync_bdev(bdevp);
+ invalidate_bdev(bdevp);
+
+ mutex_lock_nested(&bdev->bd_mutex, 1);
+ delete_partition(disk, partno);
+ mutex_unlock(&bdev->bd_mutex);
+ mutex_unlock(&bdevp->bd_mutex);
+ bdput(bdevp);
+
+ return 0;
+ case BLKPG_RESIZE_PARTITION:
+ start = p.start >> 9;
+ /* new length of partition in bytes */
+ length = p.length >> 9;
+ /* check for fit in a hd_struct */
+ if (sizeof(sector_t) == sizeof(long) &&
+ sizeof(long long) > sizeof(long)) {
+ long pstart = start, plength = length;
+ if (pstart != start || plength != length
+ || pstart < 0 || plength < 0)
+ return -EINVAL;
+ }
+ part = disk_get_part(disk, partno);
+ if (!part)
+ return -ENXIO;
+ bdevp = bdget(part_devt(part));
+ if (!bdevp) {
+ disk_put_part(part);
+ return -ENOMEM;
+ }
+ mutex_lock(&bdevp->bd_mutex);
+ mutex_lock_nested(&bdev->bd_mutex, 1);
+ if (start != part->start_sect) {
+ mutex_unlock(&bdevp->bd_mutex);
+ mutex_unlock(&bdev->bd_mutex);
+ bdput(bdevp);
+ disk_put_part(part);
+ return -EINVAL;
+ }
+ /* overlap? */
+ disk_part_iter_init(&piter, disk,
+ DISK_PITER_INCL_EMPTY);
+ while ((lpart = disk_part_iter_next(&piter))) {
+ if (lpart->partno != partno &&
+ !(start + length <= lpart->start_sect ||
+ start >= lpart->start_sect + lpart->nr_sects)
+ ) {
+ disk_part_iter_exit(&piter);
+ mutex_unlock(&bdevp->bd_mutex);
+ mutex_unlock(&bdev->bd_mutex);
+ bdput(bdevp);
+ disk_put_part(part);
+ return -EBUSY;
+ }
+ }
+ disk_part_iter_exit(&piter);
+ part_nr_sects_write(part, (sector_t)length);
+ i_size_write(bdevp->bd_inode, p.length);
+ mutex_unlock(&bdevp->bd_mutex);
+ mutex_unlock(&bdev->bd_mutex);
+ bdput(bdevp);
+ disk_put_part(part);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int blkdev_reread_part(struct block_device *bdev)
+{
+ struct gendisk *disk = bdev->bd_disk;
+ int res;
+
+ if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
+ return -EINVAL;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ if (!mutex_trylock(&bdev->bd_mutex))
+ return -EBUSY;
+ res = rescan_partitions(disk, bdev);
+ mutex_unlock(&bdev->bd_mutex);
+ return res;
+}
+
+static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
+ uint64_t len, int secure)
+{
+ unsigned long flags = 0;
+
+ if (start & 511)
+ return -EINVAL;
+ if (len & 511)
+ return -EINVAL;
+ start >>= 9;
+ len >>= 9;
+
+ if (start + len > (i_size_read(bdev->bd_inode) >> 9))
+ return -EINVAL;
+ if (secure)
+ flags |= BLKDEV_DISCARD_SECURE;
+ return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
+}
+
+static int blk_ioctl_zeroout(struct block_device *bdev, uint64_t start,
+ uint64_t len)
+{
+ if (start & 511)
+ return -EINVAL;
+ if (len & 511)
+ return -EINVAL;
+ start >>= 9;
+ len >>= 9;
+
+ if (start + len > (i_size_read(bdev->bd_inode) >> 9))
+ return -EINVAL;
+
+ return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false);
+}
+
+static int put_ushort(unsigned long arg, unsigned short val)
+{
+ return put_user(val, (unsigned short __user *)arg);
+}
+
+static int put_int(unsigned long arg, int val)
+{
+ return put_user(val, (int __user *)arg);
+}
+
+static int put_uint(unsigned long arg, unsigned int val)
+{
+ return put_user(val, (unsigned int __user *)arg);
+}
+
+static int put_long(unsigned long arg, long val)
+{
+ return put_user(val, (long __user *)arg);
+}
+
+static int put_ulong(unsigned long arg, unsigned long val)
+{
+ return put_user(val, (unsigned long __user *)arg);
+}
+
+static int put_u64(unsigned long arg, u64 val)
+{
+ return put_user(val, (u64 __user *)arg);
+}
+
+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);
+
+/*
+ * 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;
+}
+
+/*
+ * always keep this in sync with compat_blkdev_ioctl()
+ */
+int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
+ unsigned long arg)
+{
+ struct gendisk *disk = bdev->bd_disk;
+ struct backing_dev_info *bdi;
+ loff_t size;
+ int ret, n;
+ unsigned int max_sectors;
+
+ switch(cmd) {
+ case BLKFLSBUF:
+ 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;
+
+ case BLKROSET:
+ ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+ if (!is_unrecognized_ioctl(ret))
+ return ret;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ if (get_user(n, (int __user *)(arg)))
+ return -EFAULT;
+ set_device_ro(bdev, n);
+ return 0;
+
+ case BLKDISCARD:
+ case BLKSECDISCARD: {
+ uint64_t range[2];
+
+ if (!(mode & FMODE_WRITE))
+ return -EBADF;
+
+ if (copy_from_user(range, (void __user *)arg, sizeof(range)))
+ return -EFAULT;
+
+ return blk_ioctl_discard(bdev, range[0], range[1],
+ cmd == BLKSECDISCARD);
+ }
+ case BLKZEROOUT: {
+ uint64_t range[2];
+
+ if (!(mode & FMODE_WRITE))
+ return -EBADF;
+
+ if (copy_from_user(range, (void __user *)arg, sizeof(range)))
+ return -EFAULT;
+
+ return blk_ioctl_zeroout(bdev, range[0], range[1]);
+ }
+
+ case HDIO_GETGEO: {
+ struct hd_geometry geo;
+
+ if (!arg)
+ 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((struct hd_geometry __user *)arg, &geo,
+ sizeof(geo)))
+ return -EFAULT;
+ return 0;
+ }
+ case BLKRAGET:
+ case BLKFRAGET:
+ if (!arg)
+ return -EINVAL;
+ bdi = blk_get_backing_dev_info(bdev);
+ return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
+ case BLKROGET:
+ return put_int(arg, bdev_read_only(bdev) != 0);
+ case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
+ return put_int(arg, block_size(bdev));
+ case BLKSSZGET: /* get block device logical block size */
+ return put_int(arg, bdev_logical_block_size(bdev));
+ case BLKPBSZGET: /* get block device physical block size */
+ return put_uint(arg, bdev_physical_block_size(bdev));
+ case BLKIOMIN:
+ return put_uint(arg, bdev_io_min(bdev));
+ case BLKIOOPT:
+ return put_uint(arg, bdev_io_opt(bdev));
+ case BLKALIGNOFF:
+ return put_int(arg, bdev_alignment_offset(bdev));
+ case BLKDISCARDZEROES:
+ return put_uint(arg, bdev_discard_zeroes_data(bdev));
+ case BLKSECTGET:
+ max_sectors = min_t(unsigned int, USHRT_MAX,
+ queue_max_sectors(bdev_get_queue(bdev)));
+ return put_ushort(arg, max_sectors);
+ case BLKROTATIONAL:
+ return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
+ case BLKRASET:
+ case BLKFRASET:
+ if(!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ bdi = blk_get_backing_dev_info(bdev);
+ bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
+ return 0;
+ case BLKBSZSET:
+ /* set the logical block size */
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ if (!arg)
+ return -EINVAL;
+ if (get_user(n, (int __user *) arg))
+ 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;
+ case BLKPG:
+ ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
+ break;
+ case BLKRRPART:
+ ret = blkdev_reread_part(bdev);
+ break;
+ case BLKGETSIZE:
+ size = i_size_read(bdev->bd_inode);
+ if ((size >> 9) > ~0UL)
+ return -EFBIG;
+ return put_ulong(arg, size >> 9);
+ case BLKGETSIZE64:
+ return put_u64(arg, i_size_read(bdev->bd_inode));
+ case BLKTRACESTART:
+ case BLKTRACESTOP:
+ case BLKTRACESETUP:
+ case BLKTRACETEARDOWN:
+ ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
+ break;
+ default:
+ ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blkdev_ioctl);