It can be called by user space to CLONE two files.
Follow btrfs lead and define NFS_IOC_CLONE same as BTRFS_IOC_CLONE.
Thus we don't mess up userspace with too many ioctls.
Signed-off-by: Peng Tao <tao.peng@xxxxxxxxxxxxxxx>
---
fs/nfs/nfs4file.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/nfs.h | 4 ++
2 files changed, 106 insertions(+)
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index dcd39d4..dfa6620 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -4,6 +4,7 @@
* Copyright (C) 1992 Rick Sladkey
*/
#include <linux/fs.h>
+#include <linux/file.h>
#include <linux/falloc.h>
#include <linux/nfs_fs.h>
#include "internal.h"
@@ -166,8 +167,104 @@ static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t
return nfs42_proc_deallocate(filep, offset, len);
return nfs42_proc_allocate(filep, offset, len);
}
+
+static noinline long
+nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd,
+ u64 src_off, u64 dst_off, u64 count)
+{
+ struct inode *dst_inode = file_inode(dst_file);
+ struct fd src_file;
+ struct inode *src_inode;
+ int ret;
+
+ /* dst file must be opened for writing */
+ if (!(dst_file->f_mode & FMODE_WRITE))
+ return -EINVAL;
+
+ ret = mnt_want_write_file(dst_file);
+ if (ret)
+ return ret;
+
+ src_file = fdget(srcfd);
+ if (!src_file.file) {
+ ret = -EBADF;
+ goto out_drop_write;
+ }
+
+ src_inode = file_inode(src_file.file);
+
+ /* src and dst must be different files */
+ ret = -EINVAL;
+ if (src_inode == dst_inode)
+ goto out_fput;
+
+ /* src file must be opened for reading */
+ if (!(src_file.file->f_mode & FMODE_READ))
+ goto out_fput;
+
+ /* src and dst must be regular files */
+ ret = -EISDIR;
+ if (!S_ISREG(src_inode->i_mode) || !S_ISREG(dst_inode->i_mode))
+ goto out_fput;
+
+ ret = -EXDEV;
+ if (src_file.file->f_path.mnt != dst_file->f_path.mnt ||
+ src_inode->i_sb != dst_inode->i_sb)
+ goto out_fput;
+
+ /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
+ if (dst_inode < src_inode) {
+ mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_PARENT);
+ mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_CHILD);
+ } else {
+ mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_PARENT);
+ mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_CHILD);
+ }
+
+ /* flush all pending writes on both src and dst so that server
+ * has the latest data */
+ ret = nfs_sync_inode(src_inode);
+ if (ret)
+ goto out_unlock;
+ ret = nfs_sync_inode(dst_inode);
+ if (ret)
+ goto out_unlock;
+
+ ret = nfs42_proc_clone(src_file.file, dst_file, src_off, dst_off, count);
+
+ /* truncate inode page cache of the dst range so that future reads can fetch
+ * new data from server */
+ if (!ret)
+ truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
+
+out_unlock:
+ if (dst_inode < src_inode) {
+ mutex_unlock(&src_inode->i_mutex);
+ mutex_unlock(&dst_inode->i_mutex);
+ } else {
+ mutex_unlock(&dst_inode->i_mutex);
+ mutex_unlock(&src_inode->i_mutex);
+ }
+out_fput:
+ fdput(src_file);
+out_drop_write:
+ mnt_drop_write_file(dst_file);
+ return ret;
+}
#endif /* CONFIG_NFS_V4_2 */
+long nfs4_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ switch (cmd) {
+#ifdef CONFIG_NFS_V4_2
+ case NFS_IOC_CLONE:
+ return nfs42_ioctl_clone(file, arg, 0, 0, 0);
+#endif
+ }
+
+ return -ENOTTY;
+}
+
const struct file_operations nfs4_file_operations = {
#ifdef CONFIG_NFS_V4_2
.llseek = nfs4_file_llseek,
@@ -190,4 +287,9 @@ const struct file_operations nfs4_file_operations = {
#endif /* CONFIG_NFS_V4_2 */
.check_flags = nfs_check_flags,
.setlease = simple_nosetlease,
+#ifdef CONFIG_COMPAT
+ .unlocked_ioctl = nfs4_ioctl,
+#else
+ .compat_ioctl = nfs4_ioctl,
+#endif /* CONFIG_COMPAT */
};
diff --git a/include/uapi/linux/nfs.h b/include/uapi/linux/nfs.h
index 5199a36..d85748d 100644
--- a/include/uapi/linux/nfs.h
+++ b/include/uapi/linux/nfs.h
@@ -31,6 +31,10 @@
#define NFS_PIPE_DIRNAME "nfs"
+/* NFS ioctls */
+/* Let's follow btrfs lead on CLONE to avoid messing userspace */
+#define NFS_IOC_CLONE _IOW(0x94, 9, int)
+
/*
* NFS stats. The good thing with these values is that NFSv3 errors are
* a superset of NFSv2 errors (with the exception of NFSERR_WFLUSH which
--
1.8.3.1
--
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