Re: [PATCH v3] fuse: add support for copy_file_range()
From: Niels de Vos
Date: Mon Aug 06 2018 - 06:46:47 EST
Hi Miklos,
On Fri, Jun 29, 2018 at 02:53:41PM +0200, Niels de Vos wrote:
> There are several FUSE filesystems that can implement server-side copy
> or other efficient copy/duplication/clone methods. The copy_file_range()
> syscall is the standard interface that users have access to while not
> depending on external libraries that bypass FUSE.
Could you have a look at this patch? A review would be most welcome.
This has been tested with libfuse, and the pull-request for that is
available at https://github.com/libfuse/libfuse/pull/259
Marcin had a look already too, with his feedback we landed at V3 of this
change.
Thanks,
Niels
> Signed-off-by: Niels de Vos <ndevos@xxxxxxxxxx>
>
> ---
> v2: return ssize_t instead of long
> v3: add nodeid_out to fuse_copy_file_range_in for libfuse expectations
> ---
> fs/fuse/file.c | 66 +++++++++++++++++++++++
> fs/fuse/fuse_i.h | 3 ++
> include/uapi/linux/fuse.h | 107 ++++++++++++++++++++++----------------
> 3 files changed, 132 insertions(+), 44 deletions(-)
>
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index 67648ccbdd43..864939a1215d 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> @@ -3009,6 +3009,71 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
> return err;
> }
>
> +static ssize_t fuse_copy_file_range(struct file *file_in, loff_t pos_in,
> + struct file *file_out, loff_t pos_out,
> + size_t len, unsigned int flags)
> +{
> + struct fuse_file *ff_in = file_in->private_data;
> + struct fuse_file *ff_out = file_out->private_data;
> + struct inode *inode_out = file_inode(file_out);
> + struct fuse_inode *fi_out = get_fuse_inode(inode_out);
> + struct fuse_conn *fc = ff_in->fc;
> + FUSE_ARGS(args);
> + struct fuse_copy_file_range_in inarg = {
> + .fh_in = ff_in->fh,
> + .off_in = pos_in,
> + .nodeid_out = ff_out->nodeid,
> + .fh_out = ff_out->fh,
> + .off_out = pos_out,
> + .len = len,
> + .flags = flags
> + };
> + struct fuse_copy_file_range_out outarg;
> + ssize_t err;
> +
> + if (fc->no_copy_file_range)
> + return -EOPNOTSUPP;
> +
> + inode_lock(inode_out);
> + set_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
> +
> + args.in.h.opcode = FUSE_COPY_FILE_RANGE;
> + args.in.h.nodeid = ff_in->nodeid;
> + args.in.numargs = 1;
> + args.in.args[0].size = sizeof(inarg);
> + args.in.args[0].value = &inarg;
> + args.out.numargs = 1;
> + args.out.args[0].size = sizeof(outarg);
> + args.out.args[0].value = &outarg;
> + err = fuse_simple_request(fc, &args);
> + if (err == -ENOSYS) {
> + fc->no_copy_file_range = 1;
> + err = -EOPNOTSUPP;
> + }
> + if (err)
> + goto out;
> +
> + /* we might have extended the file */
> + if (outarg.size > 0) {
> + /* Size of inode_out may not have changed in case of
> + * overwrites, oh well. */
> + bool changed = fuse_write_update_size(inode_out,
> + pos_out + outarg.size);
> +
> + if (changed && fc->writeback_cache)
> + file_update_time(file_out);
> + }
> +
> + fuse_invalidate_attr(inode_out);
> +
> + err = outarg.size;
> +out:
> + clear_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
> + inode_unlock(inode_out);
> +
> + return err;
> +}
> +
> static const struct file_operations fuse_file_operations = {
> .llseek = fuse_file_llseek,
> .read_iter = fuse_file_read_iter,
> @@ -3025,6 +3090,7 @@ static const struct file_operations fuse_file_operations = {
> .compat_ioctl = fuse_file_compat_ioctl,
> .poll = fuse_file_poll,
> .fallocate = fuse_file_fallocate,
> + .copy_file_range = fuse_copy_file_range,
> };
>
> static const struct file_operations fuse_direct_io_file_operations = {
> diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
> index 5256ad333b05..ea848bb7d9e2 100644
> --- a/fs/fuse/fuse_i.h
> +++ b/fs/fuse/fuse_i.h
> @@ -637,6 +637,9 @@ struct fuse_conn {
> /** Allow other than the mounter user to access the filesystem ? */
> unsigned allow_other:1;
>
> + /** Does the filesystem support copy_file_range? */
> + unsigned no_copy_file_range:1;
> +
> /** The number of requests waiting for completion */
> atomic_t num_waiting;
>
> diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
> index 92fa24c24c92..84aa810e04c8 100644
> --- a/include/uapi/linux/fuse.h
> +++ b/include/uapi/linux/fuse.h
> @@ -116,6 +116,9 @@
> *
> * 7.27
> * - add FUSE_ABORT_ERROR
> + *
> + * 7.28
> + * - add FUSE_COPY_FILE_RANGE
> */
>
> #ifndef _LINUX_FUSE_H
> @@ -337,50 +340,51 @@ struct fuse_file_lock {
> #define FUSE_POLL_SCHEDULE_NOTIFY (1 << 0)
>
> enum fuse_opcode {
> - FUSE_LOOKUP = 1,
> - FUSE_FORGET = 2, /* no reply */
> - FUSE_GETATTR = 3,
> - FUSE_SETATTR = 4,
> - FUSE_READLINK = 5,
> - FUSE_SYMLINK = 6,
> - FUSE_MKNOD = 8,
> - FUSE_MKDIR = 9,
> - FUSE_UNLINK = 10,
> - FUSE_RMDIR = 11,
> - FUSE_RENAME = 12,
> - FUSE_LINK = 13,
> - FUSE_OPEN = 14,
> - FUSE_READ = 15,
> - FUSE_WRITE = 16,
> - FUSE_STATFS = 17,
> - FUSE_RELEASE = 18,
> - FUSE_FSYNC = 20,
> - FUSE_SETXATTR = 21,
> - FUSE_GETXATTR = 22,
> - FUSE_LISTXATTR = 23,
> - FUSE_REMOVEXATTR = 24,
> - FUSE_FLUSH = 25,
> - FUSE_INIT = 26,
> - FUSE_OPENDIR = 27,
> - FUSE_READDIR = 28,
> - FUSE_RELEASEDIR = 29,
> - FUSE_FSYNCDIR = 30,
> - FUSE_GETLK = 31,
> - FUSE_SETLK = 32,
> - FUSE_SETLKW = 33,
> - FUSE_ACCESS = 34,
> - FUSE_CREATE = 35,
> - FUSE_INTERRUPT = 36,
> - FUSE_BMAP = 37,
> - FUSE_DESTROY = 38,
> - FUSE_IOCTL = 39,
> - FUSE_POLL = 40,
> - FUSE_NOTIFY_REPLY = 41,
> - FUSE_BATCH_FORGET = 42,
> - FUSE_FALLOCATE = 43,
> - FUSE_READDIRPLUS = 44,
> - FUSE_RENAME2 = 45,
> - FUSE_LSEEK = 46,
> + FUSE_LOOKUP = 1,
> + FUSE_FORGET = 2, /* no reply */
> + FUSE_GETATTR = 3,
> + FUSE_SETATTR = 4,
> + FUSE_READLINK = 5,
> + FUSE_SYMLINK = 6,
> + FUSE_MKNOD = 8,
> + FUSE_MKDIR = 9,
> + FUSE_UNLINK = 10,
> + FUSE_RMDIR = 11,
> + FUSE_RENAME = 12,
> + FUSE_LINK = 13,
> + FUSE_OPEN = 14,
> + FUSE_READ = 15,
> + FUSE_WRITE = 16,
> + FUSE_STATFS = 17,
> + FUSE_RELEASE = 18,
> + FUSE_FSYNC = 20,
> + FUSE_SETXATTR = 21,
> + FUSE_GETXATTR = 22,
> + FUSE_LISTXATTR = 23,
> + FUSE_REMOVEXATTR = 24,
> + FUSE_FLUSH = 25,
> + FUSE_INIT = 26,
> + FUSE_OPENDIR = 27,
> + FUSE_READDIR = 28,
> + FUSE_RELEASEDIR = 29,
> + FUSE_FSYNCDIR = 30,
> + FUSE_GETLK = 31,
> + FUSE_SETLK = 32,
> + FUSE_SETLKW = 33,
> + FUSE_ACCESS = 34,
> + FUSE_CREATE = 35,
> + FUSE_INTERRUPT = 36,
> + FUSE_BMAP = 37,
> + FUSE_DESTROY = 38,
> + FUSE_IOCTL = 39,
> + FUSE_POLL = 40,
> + FUSE_NOTIFY_REPLY = 41,
> + FUSE_BATCH_FORGET = 42,
> + FUSE_FALLOCATE = 43,
> + FUSE_READDIRPLUS = 44,
> + FUSE_RENAME2 = 45,
> + FUSE_LSEEK = 46,
> + FUSE_COPY_FILE_RANGE = 47,
>
> /* CUSE specific operations */
> CUSE_INIT = 4096,
> @@ -792,4 +796,19 @@ struct fuse_lseek_out {
> uint64_t offset;
> };
>
> +struct fuse_copy_file_range_in {
> + uint64_t fh_in;
> + uint64_t off_in;
> + uint64_t nodeid_out;
> + uint64_t fh_out;
> + uint64_t off_out;
> + uint64_t len;
> + uint32_t flags;
> +};
> +
> +struct fuse_copy_file_range_out {
> + uint32_t size;
> + uint32_t padding;
> +};
> +
> #endif /* _LINUX_FUSE_H */
> --
> 2.17.1
>