[PATCH v3 04/10] block: Introduce a new ioctl for copy
From: Nitesh Shetty <hidden>
Date: 2022-02-14 08:35:56
Also in:
dm-devel, linux-fsdevel, linux-nvme, linux-scsi, lkml
Subsystem:
block layer, filesystems (vfs and infrastructure), the rest · Maintainers:
Jens Axboe, Alexander Viro, Christian Brauner, Linus Torvalds
Add new BLKCOPY ioctl that offloads copying of one or more sources ranges
to one or more destination in a device. COPY ioctl accepts a 'copy_range'
structure that contains no of range, a reserved field , followed by an
array of ranges. Each source range is represented by 'range_entry' that
contains source start offset, destination start offset and length of
source ranges (in bytes)
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 entries with [dest,src,len],
* [32768, 0, 4096] [36864, 4096, 4096] [40960,8192,4096] on same device */
int main(void)
{
int i, ret, fd;
unsigned long src = 0, dst = 32768, len = 4096;
struct copy_range *cr;
cr = (struct copy_range *)malloc(sizeof(*cr)+
(sizeof(struct range_entry)*3));
cr->nr_range = 3;
cr->reserved = 0;
for (i = 0; i< cr->nr_range; i++, src += len, dst += len) {
cr->range_list[i].dst = dst;
cr->range_list[i].src = src;
cr->range_list[i].len = len;
cr->range_list[i].comp_len = 0;
}
fd = open("/dev/nvme0n1", O_RDWR);
if (fd < 0) return 1;
ret = ioctl(fd, BLKCOPY, cr);
if (ret != 0)
printf("copy failed, ret= %d\n", ret);
for (i=0; i< cr->nr_range; i++)
if (cr->range_list[i].len != cr->range_list[i].comp_len)
printf("Partial copy for entry %d: requested %llu, completed %llu\n",
i, cr->range_list[i].len,
cr->range_list[i].comp_len);
close(fd);
free(cr);
return ret;
}
Signed-off-by: Nitesh Shetty <redacted>
Signed-off-by: Javier González <redacted>
Signed-off-by: Arnav Dawn <redacted>
---
block/ioctl.c | 32 ++++++++++++++++++++++++++++++++
include/uapi/linux/fs.h | 9 +++++++++
2 files changed, 41 insertions(+)
diff --git a/block/ioctl.c b/block/ioctl.c
index 4a86340133e4..a2dc2cfbae6d 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c@@ -124,6 +124,36 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode, return err; } +static int blk_ioctl_copy(struct block_device *bdev, fmode_t mode, + unsigned long arg) +{ + struct copy_range crange, *ranges = NULL; + size_t payload_size = 0; + int ret; + + if (!(mode & FMODE_WRITE)) + return -EBADF; + + if (copy_from_user(&crange, (void __user *)arg, sizeof(crange))) + return -EFAULT; + + if (unlikely(!crange.nr_range || crange.reserved || crange.nr_range >= MAX_COPY_NR_RANGE)) + return -EINVAL; + + payload_size = (crange.nr_range * sizeof(struct range_entry)) + sizeof(crange); + + ranges = memdup_user((void __user *)arg, payload_size); + if (IS_ERR(ranges)) + return PTR_ERR(ranges); + + ret = blkdev_issue_copy(bdev, ranges->nr_range, ranges->range_list, bdev, GFP_KERNEL); + if (copy_to_user((void __user *)arg, ranges, payload_size)) + ret = -EFAULT; + + kfree(ranges); + return ret; +} + static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, unsigned long arg) {
@@ -455,6 +485,8 @@ 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 55bca8f6e8ed..190911ea4311 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h@@ -78,6 +78,14 @@ struct range_entry { __u64 comp_len; }; +struct copy_range { + __u64 nr_range; + __u64 reserved; + + /* Range_list always must be at the end */ + struct range_entry range_list[]; +}; + /* extent-same (dedupe) ioctls; these MUST match the btrfs ioctl definitions */ #define FILE_DEDUPE_RANGE_SAME 0 #define FILE_DEDUPE_RANGE_DIFFERS 1
@@ -199,6 +207,7 @@ 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)
--
2.30.0-rc0