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.
Signed-off-by: Niels de Vos <ndevos@xxxxxxxxxx>
---
v2: return ssize_t instead of long
---
fs/fuse/file.c | 65 +++++++++++++++++++++++
fs/fuse/fuse_i.h | 3 ++
include/uapi/linux/fuse.h | 106 ++++++++++++++++++++++----------------
3 files changed, 130 insertions(+), 44 deletions(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 67648ccbdd43..be8b3da4b788 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3009,6 +3009,70 @@ 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,
+ .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 +3089,7 @@ 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..77330fa510f1 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 +796,18 @@ struct fuse_lseek_out {
uint64_t offset;
};
+struct fuse_copy_file_range_in {
+ uint64_t fh_in;
+ uint64_t off_in;
+ 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
