[PATCH 4/7] block: Introduce a new ioctl for simple copy
From: SelvaKumar S <hidden>
Date: 2021-08-17 11:29:26
Also in:
dm-devel, linux-api, linux-fsdevel, linux-nvme, linux-scsi
Subsystem:
block layer, filesystems (vfs and infrastructure), the rest · Maintainers:
Jens Axboe, Alexander Viro, Christian Brauner, Linus Torvalds
From: Nitesh Shetty <redacted>
Add new BLKCOPY ioctl that offloads copying of one or more sources ranges
to a destination in the device. COPY ioctl accepts a 'copy_range'
structure that contains destination (in sectors), no of sources and
pointer to the array of source ranges. Each source range is represented by
'range_entry' that contains start and length of source ranges (in sectors)
MAX_COPY_NR_RANGE, limits the number of entries for the IOCTL and
MAX_COPY_TOTAL_LENGTH limits the total copy length, IOCTL can handle.
Example code, to issue BLKCOPY:
/* Sample example to copy three source-ranges [0, 8] [16, 8] [32,8] to
* [64,24], on the same device */
int main(void)
{
int ret, fd;
struct range_entry source_range[] = {{.src = 0, .len = 8},
{.src = 16, .len = 8}, {.src = 32, .len = 8},};
struct copy_range cr;
cr.dest = 64;
cr.nr_range = 3;
cr.range_list = (__u64)&source_range;
fd = open("/dev/nvme0n1", O_RDWR);
if (fd < 0) return 1;
ret = ioctl(fd, BLKCOPY, &cr);
if (ret < 0) printf("copy failure\n");
close(fd);
return ret;
}
Signed-off-by: Nitesh Shetty <redacted>
Signed-off-by: SelvaKumar S <redacted>
Signed-off-by: Kanchan Joshi <redacted>
---
block/ioctl.c | 33 +++++++++++++++++++++++++++++++++
include/uapi/linux/fs.h | 8 ++++++++
2 files changed, 41 insertions(+)
diff --git a/block/ioctl.c b/block/ioctl.c
index eb0491e90b9a..2af56d01e9fe 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c@@ -143,6 +143,37 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode, GFP_KERNEL, flags); } +static int blk_ioctl_copy(struct block_device *bdev, fmode_t mode, + unsigned long arg) +{ + struct copy_range crange; + struct range_entry *rlist; + int ret; + + if (!(mode & FMODE_WRITE)) + return -EBADF; + + if (copy_from_user(&crange, (void __user *)arg, sizeof(crange))) + return -EFAULT; + + rlist = kmalloc_array(crange.nr_range, sizeof(*rlist), + GFP_KERNEL); + if (!rlist) + return -ENOMEM; + + if (copy_from_user(rlist, (void __user *)crange.range_list, + sizeof(*rlist) * crange.nr_range)) { + ret = -EFAULT; + goto out; + } + + ret = blkdev_issue_copy(bdev, crange.nr_range, rlist, bdev, crange.dest, + GFP_KERNEL, 0); +out: + kfree(rlist); + return ret; +} + static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, unsigned long arg) {
@@ -468,6 +499,8 @@ static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode, case BLKSECDISCARD: return blk_ioctl_discard(bdev, mode, arg, BLKDEV_DISCARD_SECURE); + case BLKCOPY: + return blk_ioctl_copy(bdev, mode, arg); case BLKZEROOUT: return blk_ioctl_zeroout(bdev, mode, arg); case BLKGETDISKSEQ:
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index 7a97b588d892..4183688ff398 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h@@ -76,6 +76,13 @@ struct range_entry { __u64 len; }; +struct copy_range { + __u64 dest; + __u64 nr_range; + __u64 range_list; + __u64 rsvd; +}; + /* extent-same (dedupe) ioctls; these MUST match the btrfs ioctl definitions */ #define FILE_DEDUPE_RANGE_SAME 0 #define FILE_DEDUPE_RANGE_DIFFERS 1
@@ -197,6 +204,7 @@ struct fsxattr { #define BLKROTATIONAL _IO(0x12,126) #define BLKZEROOUT _IO(0x12,127) #define BLKGETDISKSEQ _IOR(0x12,128,__u64) +#define BLKCOPY _IOWR(0x12, 129, struct copy_range) /* * A jump here: 130-136 are reserved for zoned block devices * (see uapi/linux/blkzoned.h)
--
2.25.1