Now that a few file systems are adding clone functionality, namingly
btrfs, CIFS, NFS (in another series) and XFS
(ttp://oss.sgi.com/archives/xfs/2015-06/msg00407.html), it makes sense
to pull the ioctl to common code.
Signed-off-by: Peng Tao <tao.peng@xxxxxxxxxxxxxxx>
---
fs/ioctl.c | 40 ++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/fs.h | 9 +++++++++
2 files changed, 49 insertions(+)
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 5d01d26..9a78426 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -215,6 +215,40 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg)
return error;
}
+static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
+ u64 off, u64 olen, u64 destoff)
+{
+ struct fd src_file = fdget(srcfd);
+ struct inode *src_inode;
+ int ret;
+
+ if (!src_file.file)
+ return -EBADF;
+ /* olen == 0 means src off to eof */
+ if (olen == 0) {
+ src_inode = file_inode(src_file.file);
+ olen = i_size_read(src_inode) - off;
+ }
+ ret = vfs_copy_file_range(src_file.file, off, dst_file,
+ destoff, olen, COPY_FILE_CLONE_ONLY);
+ /* vfs_copy_file_range returns bytes copied */
+ if (ret > 0)
+ ret = 0;
+
+ fdput(src_file);
+ return ret;
+}
+
+static long ioctl_file_clone_range(struct file *file, void __user *argp)
+{
+ struct file_clone_range args;
+
+ if (copy_from_user(&args, argp, sizeof(args)))
+ return -EFAULT;
+ return ioctl_file_clone(file, args.src_fd, args.src_offset,
+ args.src_length, args.dest_offset);
+}
+
#ifdef CONFIG_BLOCK
static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
@@ -600,6 +634,12 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
case FIGETBSZ:
return put_user(inode->i_sb->s_blocksize, argp);
+ case FICLONE:
+ return ioctl_file_clone(filp, arg, 0, 0, 0);
+
+ case FICLONERANGE:
+ return ioctl_file_clone_range(filp, argp);
+
default:
if (S_ISREG(inode->i_mode))
error = file_ioctl(filp, cmd, arg);
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index 9b964a5..ac7f1c5 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -39,6 +39,13 @@
#define RENAME_EXCHANGE (1 << 1) /* Exchange source and dest */
#define RENAME_WHITEOUT (1 << 2) /* Whiteout source */
+struct file_clone_range {
+ __s64 src_fd;
+ __u64 src_offset;
+ __u64 src_length;
+ __u64 dest_offset;
+};
+
struct fstrim_range {
__u64 start;
__u64 len;
@@ -159,6 +166,8 @@ struct inodes_stat_t {
#define FIFREEZE _IOWR('X', 119, int) /* Freeze */
#define FITHAW _IOWR('X', 120, int) /* Thaw */
#define FITRIM _IOWR('X', 121, struct fstrim_range) /* Trim */
+#define FICLONE _IOW(0x94, 9, int) /* Clone */
+#define FICLONERANGE _IOW(0x94, 13, struct file_clone_range) /* Clone range */
#define FS_IOC_GETFLAGS _IOR('f', 1, long)
#define FS_IOC_SETFLAGS _IOW('f', 2, long)
--
1.8.3.1
--
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