vfs: allow copy_file_range to copy across devices

We want to enable cross-filesystem copy_file_range functionality
where possible, so push the "same superblock only" checks down to
the individual filesystem callouts so they can make their own
decisions about cross-superblock copy offload and fallack to
generic_copy_file_range() for cross-superblock copy.

[Amir] We do not call ->remap_file_range() in case the files are not
on the same sb and do not call ->copy_file_range() in case the files
do not belong to the same filesystem driver.

This changes behavior of the copy_file_range(2) syscall, which will
now allow cross filesystem in-kernel copy.  CIFS already supports
cross-superblock copy, between two shares to the same server. This
functionality will now be available via the copy_file_range(2) syscall.

Cc: Steve French <stfrench@microsoft.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Amir Goldstein 2019-06-05 08:04:50 -07:00 committed by Darrick J. Wong
parent 8c3f406c09
commit 5dae222a5f
5 changed files with 24 additions and 10 deletions

View File

@ -1909,6 +1909,8 @@ static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off,
if (src_inode == dst_inode)
return -EINVAL;
if (src_inode->i_sb != dst_inode->i_sb)
return -EXDEV;
if (ceph_snap(dst_inode) != CEPH_NOSNAP)
return -EROFS;
@ -2109,7 +2111,7 @@ static ssize_t ceph_copy_file_range(struct file *src_file, loff_t src_off,
ret = __ceph_copy_file_range(src_file, src_off, dst_file, dst_off,
len, flags);
if (ret == -EOPNOTSUPP)
if (ret == -EOPNOTSUPP || ret == -EXDEV)
ret = generic_copy_file_range(src_file, src_off, dst_file,
dst_off, len, flags);
return ret;

View File

@ -1149,7 +1149,7 @@ static ssize_t cifs_copy_file_range(struct file *src_file, loff_t off,
len, flags);
free_xid(xid);
if (rc == -EOPNOTSUPP)
if (rc == -EOPNOTSUPP || rc == -EXDEV)
rc = generic_copy_file_range(src_file, off, dst_file,
destoff, len, flags);
return rc;

View File

@ -3142,6 +3142,9 @@ static ssize_t __fuse_copy_file_range(struct file *file_in, loff_t pos_in,
if (fc->no_copy_file_range)
return -EOPNOTSUPP;
if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
return -EXDEV;
if (fc->writeback_cache) {
inode_lock(inode_in);
err = fuse_writeback_range(inode_in, pos_in, pos_in + len);
@ -3203,7 +3206,7 @@ static ssize_t fuse_copy_file_range(struct file *src_file, loff_t src_off,
ret = __fuse_copy_file_range(src_file, src_off, dst_file, dst_off,
len, flags);
if (ret == -EOPNOTSUPP)
if (ret == -EOPNOTSUPP || ret == -EXDEV)
ret = generic_copy_file_range(src_file, src_off, dst_file,
dst_off, len, flags);
return ret;

View File

@ -133,6 +133,9 @@ static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
size_t count, unsigned int flags)
{
/* Only offload copy if superblock is the same */
if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
return -EXDEV;
if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY))
return -EOPNOTSUPP;
if (file_inode(file_in) == file_inode(file_out))
@ -148,7 +151,7 @@ static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
flags);
if (ret == -EOPNOTSUPP)
if (ret == -EOPNOTSUPP || ret == -EXDEV)
ret = generic_copy_file_range(file_in, pos_in, file_out,
pos_out, count, flags);
return ret;

View File

@ -1599,7 +1599,16 @@ static ssize_t do_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)
{
if (file_out->f_op->copy_file_range)
/*
* Although we now allow filesystems to handle cross sb copy, passing
* a file of the wrong filesystem type to filesystem driver can result
* in an attempt to dereference the wrong type of ->private_data, so
* avoid doing that until we really have a good reason. NFS defines
* several different file_system_type structures, but they all end up
* using the same ->copy_file_range() function pointer.
*/
if (file_out->f_op->copy_file_range &&
file_out->f_op->copy_file_range == file_in->f_op->copy_file_range)
return file_out->f_op->copy_file_range(file_in, pos_in,
file_out, pos_out,
len, flags);
@ -1622,10 +1631,6 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
if (flags != 0)
return -EINVAL;
/* this could be relaxed once a method supports cross-fs copies */
if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
return -EXDEV;
ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len,
flags);
if (unlikely(ret))
@ -1648,7 +1653,8 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
* Try cloning first, this is supported by more file systems, and
* more efficient if both clone and copy are supported (e.g. NFS).
*/
if (file_in->f_op->remap_file_range) {
if (file_in->f_op->remap_file_range &&
file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) {
loff_t cloned;
cloned = file_in->f_op->remap_file_range(file_in, pos_in,