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authorChristoph Hellwig <hch@lst.de>2015-12-03 14:59:50 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2015-12-08 07:11:33 +0300
commit04b38d601239b4d9be641b412cf4b7456a041c67 (patch)
tree196b5fa72848de2a98e09af86099d99da70f2833 /fs/ioctl.c
parentacc15575e78e534c12549d8057a692f490a50f61 (diff)
downloadlinux-04b38d601239b4d9be641b412cf4b7456a041c67.tar.xz
vfs: pull btrfs clone API to vfs layer
The btrfs clone ioctls are now adopted by other file systems, with NFS and CIFS already having support for them, and XFS being under active development. To avoid growth of various slightly incompatible implementations, add one to the VFS. Note that clones are different from file copies in several ways: - they are atomic vs other writers - they support whole file clones - they support 64-bit legth clones - they do not allow partial success (aka short writes) - clones are expected to be a fast metadata operation Because of that it would be rather cumbersome to try to piggyback them on top of the recent clone_file_range infrastructure. The converse isn't true and the clone_file_range system call could try clone file range as a first attempt to copy, something that further patches will enable. Based on earlier work from Peng Tao. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/ioctl.c')
-rw-r--r--fs/ioctl.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 5d01d2638ca5..84c6e79829ab 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -215,6 +215,29 @@ 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);
+ int ret;
+
+ if (!src_file.file)
+ return -EBADF;
+ ret = vfs_clone_file_range(src_file.file, off, dst_file, destoff, olen);
+ 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 +623,12 @@ 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);