nfs: allow intra-file CLONE
Originally CLONE didn't allow for intra-file clones, but we recently
updated the spec to support this feature which is also supported by
local Linux file systems.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index e45f686..61f1c1c 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -203,6 +203,7 @@
struct fd src_file;
struct inode *src_inode;
unsigned int bs = server->clone_blksize;
+ bool same_inode = false;
int ret;
/* dst file must be opened for writing */
@@ -221,10 +222,8 @@
src_inode = file_inode(src_file.file);
- /* src and dst must be different files */
- ret = -EINVAL;
if (src_inode == dst_inode)
- goto out_fput;
+ same_inode = true;
/* src file must be opened for reading */
if (!(src_file.file->f_mode & FMODE_READ))
@@ -249,8 +248,16 @@
goto out_fput;
}
+ /* verify if ranges are overlapped within the same file */
+ if (same_inode) {
+ if (dst_off + count > src_off && dst_off < src_off + count)
+ goto out_fput;
+ }
+
/* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
- if (dst_inode < src_inode) {
+ if (same_inode) {
+ mutex_lock(&src_inode->i_mutex);
+ } else 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 {
@@ -275,7 +282,9 @@
truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
out_unlock:
- if (dst_inode < src_inode) {
+ if (same_inode) {
+ mutex_unlock(&src_inode->i_mutex);
+ } else if (dst_inode < src_inode) {
mutex_unlock(&src_inode->i_mutex);
mutex_unlock(&dst_inode->i_mutex);
} else {