[PATCH 1/5] block: cleanup blkdev_ioctl
From: hch@lst.de (Christoph Hellwig)
Date: 2015-08-26 16:07:19
Also in:
dm-devel, linux-api, linux-scsi, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
Split out helpers for all non-trivial ioctls to make this function simpler, and also start passing around a pointer version of the argument, as that's what most ioctl handlers actually need. Signed-off-by: Christoph Hellwig <hch at lst.de> --- block/ioctl.c | 227 ++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 127 insertions(+), 100 deletions(-)
diff --git a/block/ioctl.c b/block/ioctl.c
index 8061eba..df62b47 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c@@ -193,10 +193,20 @@ int blkdev_reread_part(struct block_device *bdev) } EXPORT_SYMBOL(blkdev_reread_part); -static int blk_ioctl_discard(struct block_device *bdev, uint64_t start, - uint64_t len, int secure) +static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode, + unsigned long arg, unsigned long flags) { - unsigned long flags = 0; + uint64_t range[2]; + uint64_t start, len; + + if (!(mode & FMODE_WRITE)) + return -EBADF; + + if (copy_from_user(range, (void __user *)arg, sizeof(range))) + return -EFAULT; + + start = range[0]; + len = range[1]; if (start & 511) return -EINVAL;
@@ -207,14 +217,24 @@ static int blk_ioctl_discard(struct block_device *bdev, uint64_t start, 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) +static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, + unsigned long arg) { + uint64_t range[2]; + uint64_t start, len; + + if (!(mode & FMODE_WRITE)) + return -EBADF; + + 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)
@@ -295,89 +315,115 @@ static inline int is_unrecognized_ioctl(int ret) 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) +static int blkdev_flushbuf(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; + int ret; - 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; + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; - fsync_bdev(bdev); - invalidate_bdev(bdev); - return 0; + ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); + if (!is_unrecognized_ioctl(ret)) + return ret; - 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; + fsync_bdev(bdev); + invalidate_bdev(bdev); + return 0; +} - case BLKDISCARD: - case BLKSECDISCARD: { - uint64_t range[2]; +static int blkdev_roset(struct block_device *bdev, fmode_t mode, + unsigned cmd, unsigned long arg) +{ + int ret, n; - if (!(mode & FMODE_WRITE)) - return -EBADF; + 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; +} - if (copy_from_user(range, (void __user *)arg, sizeof(range))) - return -EFAULT; +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; - return blk_ioctl_discard(bdev, range[0], range[1], - cmd == BLKSECDISCARD); - } - case BLKZEROOUT: { - uint64_t range[2]; + 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; +} - if (!(mode & FMODE_WRITE)) - return -EBADF; +/* set the logical block size */ +static int blkdev_bszset(struct block_device *bdev, fmode_t mode, + int __user *argp) +{ + int ret, n; - if (copy_from_user(range, (void __user *)arg, sizeof(range))) - return -EFAULT; + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + if (!argp) + return -EINVAL; + if (get_user(n, argp)) + return -EFAULT; - return blk_ioctl_zeroout(bdev, range[0], range[1]); + if (!(mode & FMODE_EXCL)) { + bdgrab(bdev); + if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0) + return -EBUSY; } - case HDIO_GETGEO: { - struct hd_geometry geo; + ret = set_blocksize(bdev, n); + if (!(mode & FMODE_EXCL)) + blkdev_put(bdev, mode | FMODE_EXCL); + return ret; +} - 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; - } +/* + * 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 backing_dev_info *bdi; + void __user *argp = (void __user *)arg; + loff_t size; + 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 HDIO_GETGEO: + return blkdev_getgeo(bdev, argp); case BLKRAGET: case BLKFRAGET: if (!arg)
@@ -414,28 +460,11 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, 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; + return blkdev_bszset(bdev, mode, argp); case BLKPG: - ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg); - break; + return blkpg_ioctl(bdev, argp); case BLKRRPART: - ret = blkdev_reread_part(bdev); - break; + return blkdev_reread_part(bdev); case BLKGETSIZE: size = i_size_read(bdev->bd_inode); if ((size >> 9) > ~0UL)
@@ -447,11 +476,9 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, case BLKTRACESTOP: case BLKTRACESETUP: case BLKTRACETEARDOWN: - ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg); - break; + return blk_trace_ioctl(bdev, cmd, argp); default: - ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); + return __blkdev_driver_ioctl(bdev, mode, cmd, arg); } - return ret; } EXPORT_SYMBOL_GPL(blkdev_ioctl);
--
1.9.1