Merge tag 'copy-file-range-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull copy_file_range updates from Darrick Wong:
 "This fixes numerous parameter checking problems and inconsistent
  behaviors in the new(ish) copy_file_range system call.

  Now the system call will actually check its range parameters
  correctly; refuse to copy into files for which the caller does not
  have sufficient privileges; update mtime and strip setuid like file
  writes are supposed to do; and allows copying up to the EOF of the
  source file instead of failing the call like we used to.

  Summary:

   - Create a generic copy_file_range handler and make individual
     filesystems responsible for calling it (i.e. no more assuming that
     do_splice_direct will work or is appropriate)

   - Refactor copy_file_range and remap_range parameter checking where
     they are the same

   - Install missing copy_file_range parameter checking(!)

   - Remove suid/sgid and update mtime like any other file write

   - Change the behavior so that a copy range crossing the source file's
     eof will result in a short copy to the source file's eof instead of
     EINVAL

   - Permit filesystems to decide if they want to handle
     cross-superblock copy_file_range in their local handlers"

* tag 'copy-file-range-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  fuse: copy_file_range needs to strip setuid bits and update timestamps
  vfs: allow copy_file_range to copy across devices
  xfs: use file_modified() helper
  vfs: introduce file_modified() helper
  vfs: add missing checks to copy_file_range
  vfs: remove redundant checks from generic_remap_checks()
  vfs: introduce generic_file_rw_checks()
  vfs: no fallback for ->copy_file_range
  vfs: introduce generic_copy_file_range()

1 files changed, 20 insertions, 3 deletions

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 183c37c0a8fc..c5517ffeb11c 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1889,9 +1889,9 @@ static int is_file_size_ok(struct inode *src_inode, struct inode *dst_inode,
 	return 0;
 }
 
-static ssize_t ceph_copy_file_range(struct file *src_file, loff_t src_off,
-				    struct file *dst_file, loff_t dst_off,
-				    size_t len, unsigned int flags)
+static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off,
+				      struct file *dst_file, loff_t dst_off,
+				      size_t len, unsigned int flags)
 {
 	struct inode *src_inode = file_inode(src_file);
 	struct inode *dst_inode = file_inode(dst_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;
 
@@ -2100,6 +2102,21 @@ out:
 	return ret;
 }
 
+static ssize_t ceph_copy_file_range(struct file *src_file, loff_t src_off,
+				    struct file *dst_file, loff_t dst_off,
+				    size_t len, unsigned int flags)
+{
+	ssize_t ret;
+
+	ret = __ceph_copy_file_range(src_file, src_off, dst_file, dst_off,
+				     len, flags);
+
+	if (ret == -EOPNOTSUPP || ret == -EXDEV)
+		ret = generic_copy_file_range(src_file, src_off, dst_file,
+					      dst_off, len, flags);
+	return ret;
+}
+
 const struct file_operations ceph_file_fops = {
 	.open = ceph_open,
 	.release = ceph_release,