From 8ede205541ff05bd096749a9f00bde6d754b4e22 Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@redhat.com>
Date: Wed, 18 Jul 2018 15:44:42 +0200
Subject: [PATCH] ovl: add reflink/copyfile/dedup support
Since set of arguments are so similar, handle in a common helper.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/overlayfs/file.c | 87 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 87 insertions(+)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index c49af241c0013..cd75b53f14976 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -389,6 +389,89 @@ static long ovl_compat_ioctl(struct file *file, unsigned int cmd,
return ovl_ioctl(file, cmd, arg);
}
+enum ovl_copyop {
+ OVL_COPY,
+ OVL_CLONE,
+ OVL_DEDUPE,
+};
+
+static ssize_t ovl_copyfile(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ u64 len, unsigned int flags, enum ovl_copyop op)
+{
+ struct inode *inode_out = file_inode(file_out);
+ struct fd real_in, real_out;
+ const struct cred *old_cred;
+ ssize_t ret;
+
+ ret = ovl_real_fdget(file_out, &real_out);
+ if (ret)
+ return ret;
+
+ ret = ovl_real_fdget(file_in, &real_in);
+ if (ret) {
+ fdput(real_out);
+ return ret;
+ }
+
+ old_cred = ovl_override_creds(file_inode(file_out)->i_sb);
+ switch (op) {
+ case OVL_COPY:
+ ret = vfs_copy_file_range(real_in.file, pos_in,
+ real_out.file, pos_out, len, flags);
+ break;
+
+ case OVL_CLONE:
+ ret = vfs_clone_file_range(real_in.file, pos_in,
+ real_out.file, pos_out, len);
+ break;
+
+ case OVL_DEDUPE:
+ ret = vfs_dedupe_file_range_one(real_in.file, pos_in,
+ real_out.file, pos_out, len);
+ break;
+ }
+ revert_creds(old_cred);
+
+ /* Update size */
+ ovl_copyattr(ovl_inode_real(inode_out), inode_out);
+
+ fdput(real_in);
+ fdput(real_out);
+
+ return ret;
+}
+
+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,
+ OVL_COPY);
+}
+
+static int ovl_clone_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out, u64 len)
+{
+ return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, 0,
+ OVL_CLONE);
+}
+
+static int ovl_dedupe_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out, u64 len)
+{
+ /*
+ * Don't copy up because of a dedupe request, this wouldn't make sense
+ * most of the time (data would be duplicated instead of deduplicated).
+ */
+ if (!ovl_inode_upper(file_inode(file_in)) ||
+ !ovl_inode_upper(file_inode(file_out)))
+ return -EPERM;
+
+ return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, 0,
+ OVL_DEDUPE);
+}
+
const struct file_operations ovl_file_operations = {
.open = ovl_open,
.release = ovl_release,
@@ -400,4 +483,8 @@ const struct file_operations ovl_file_operations = {
.fallocate = ovl_fallocate,
.unlocked_ioctl = ovl_ioctl,
.compat_ioctl = ovl_compat_ioctl,
+
+ .copy_file_range = ovl_copy_file_range,
+ .clone_file_range = ovl_clone_file_range,
+ .dedupe_file_range = ovl_dedupe_file_range,
};
--
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