[PATCH 03/11] vfs: no fallback for ->copy_file_range

Dave Chinner
2018-12-03T08:34:29Z

From: Dave Chinner <dchinner@redhat.com>

Now that we have generic_copy_file_range(), remove it as a fallback
case when offloads fail. This puts the responsibility for executing
fallbacks on the filesystems that implement ->copy_file_range and
allows us to add operational validity checks to
generic_copy_file_range().

Rework vfs_copy_file_range() to call a new do_copy_file_range()
helper to exceute the copying callout, and move calls to
generic_file_copy_range() into filesystem methods where they
currently return failures.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/ceph/file.c | 17 ++++++++++++++++-
fs/cifs/cifsfs.c | 4 ++++
fs/fuse/file.c | 17 ++++++++++++++++-
fs/nfs/nfs4file.c | 4 ++++
fs/overlayfs/file.c | 9 ++++++++-
fs/read_write.c | 24 +++++++++++++++---------
6 files changed, 63 insertions(+), 12 deletions(-)

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 189df668b6a0..cf29f0410dcb 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1885,7 +1885,7 @@ 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,
+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)
{
@@ -2096,6 +2096,21 @@ static ssize_t ceph_copy_file_range(struct file *src_file, loff_t src_off,
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 = 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,
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 865706edb307..5ef4baec6234 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -1141,6 +1141,10 @@ static ssize_t cifs_copy_file_range(struct file *src_file, loff_t off,
rc = cifs_file_copychunk_range(xid, src_file, off, dst_file, destoff,
len, flags);
free_xid(xid);
+
+ if (rc == -EOPNOTSUPP)
+ rc = generic_copy_file_range(src_file, off, dst_file,
+ destoff, len, flags);
return rc;
}

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index b52f9baaa3e7..b86fb0298739 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3024,7 +3024,7 @@ 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,
+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)
{
@@ -3100,6 +3100,21 @@ static ssize_t fuse_copy_file_range(struct file *file_in, loff_t pos_in,
return err;
}

+static ssize_t fuse_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 = __fuse_copy_file_range(src_file, src_off, dst_file, dst_off,
+ len, flags);
+
+ if (ret == -EOPNOTSUPP)
+ ret = generic_copy_file_range(src_file, src_off, dst_file,
+ dst_off, len, flags);
+ return ret;
+}
+
static const struct file_operations fuse_file_operations = {
.llseek = fuse_file_llseek,
.read_iter = fuse_file_read_iter,
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 46d691ba04bc..d7766a6eb0f4 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -141,6 +141,10 @@ static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
if (ret == -EAGAIN)
goto retry;
+
+ if (ret == -EOPNOTSUPP)
+ ret = generic_copy_file_range(file_in, pos_in, file_out,
+ pos_out, count, flags);
return ret;
}

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 84dd957efa24..68736e5d6a56 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -486,8 +486,15 @@ static ssize_t ovl_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)
{
- return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags,
+ ssize_t ret;
+
+ ret = ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags,
OVL_COPY);
+
+ if (ret == -EOPNOTSUPP)
+ ret = generic_copy_file_range(file_in, pos_in, file_out,
+ pos_out, len, flags);
+ return ret;
}

static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in,
diff --git a/fs/read_write.c b/fs/read_write.c
index 50114694c98b..44339b44accc 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1570,6 +1570,18 @@ ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
}
EXPORT_SYMBOL(generic_copy_file_range);

+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)
+ return file_out->f_op->copy_file_range(file_in, pos_in, file_out,
+ pos_out, len, flags);
+
+ return generic_copy_file_range(file_in, &pos_in, file_out, &pos_out,
+ len, flags);
+}
+
/*
* copy_file_range() differs from regular file read and write in that it
* specifically allows return partial success. When it does so is up to
@@ -1634,15 +1646,9 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
}
}

- if (file_out->f_op->copy_file_range) {
- ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
- pos_out, len, flags);
- if (ret != -EOPNOTSUPP)
- goto done;
- }
-
- ret = generic_copy_file_range(file_in, &pos_in, file_out, &pos_out,
- len, flags);
+ ret = do_copy_file_range(file_in, pos_in, file_out, pos_out, len,
+ flags);
+ WARN_ON_ONCE(ret == -EOPNOTSUPP);
done:
if (ret > 0) {
fsnotify_access(file_in);
--
2.19.1