[PATCH v2 2/8] vfs: no fallback for ->copy_file_range

Amir Goldstein
2019-05-26T06:11:18Z

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.

[Amir] overlayfs is not responsible of executing the fallback.
It is the responsibility of the underlying filesystem.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
fs/ceph/file.c | 21 ++++++++++++++++++---
fs/cifs/cifsfs.c | 4 ++++
fs/fuse/file.c | 21 ++++++++++++++++++---
fs/nfs/nfs4file.c | 20 +++++++++++++++++---
fs/read_write.c | 25 ++++++++++++++++---------
5 files changed, 73 insertions(+), 18 deletions(-)

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 305daf043eb0..e87f7b2023af 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);
@@ -2100,6 +2100,21 @@ 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 f5fcd6360056..c65823270313 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -1148,6 +1148,10 @@ 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 3959f08279e6..e03901ae729b 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3097,9 +3097,9 @@ 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)
+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;
@@ -3173,6 +3173,21 @@ 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 cf42a8b939e3..4842f3ab3161 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -129,9 +129,9 @@ nfs4_file_flush(struct file *file, fl_owner_t id)
}

#ifdef CONFIG_NFS_V4_2
-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)
+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)
{
if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY))
return -EOPNOTSUPP;
@@ -140,6 +140,20 @@ static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
}

+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)
+{
+ ssize_t ret;
+
+ ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
+ flags);
+ if (ret == -EOPNOTSUPP)
+ ret = generic_copy_file_range(file_in, pos_in, file_out,
+ pos_out, count, flags);
+ return ret;
+}
+
static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
{
loff_t ret;
diff --git a/fs/read_write.c b/fs/read_write.c
index 676b02fae589..b63dcb4e4fe9 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1595,6 +1595,19 @@ 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
@@ -1655,15 +1668,9 @@ 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);
--
2.17.1