1 files changed, 17 insertions, 14 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 994d66fbb446..d41c149fae75 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -36,6 +36,7 @@
 #endif /* CONFIG_NFSD_V3 */
 
 #ifdef CONFIG_NFSD_V4
+#include "../internal.h"
 #include "acl.h"
 #include "idmap.h"
 #endif /* CONFIG_NFSD_V4 */
@@ -217,10 +218,16 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		host_err = PTR_ERR(dentry);
 		if (IS_ERR(dentry))
 			goto out_nfserr;
-		/*
-		 * check if we have crossed a mount point ...
-		 */
 		if (nfsd_mountpoint(dentry, exp)) {
+			/*
+			 * We don't need the i_mutex after all.  It's
+			 * still possible we could open this (regular
+			 * files can be mountpoints too), but the
+			 * i_mutex is just there to prevent renames of
+			 * something that we might be about to delegate,
+			 * and a mountpoint won't be renamed:
+			 */
+			fh_unlock(fhp);
 			if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
 				dput(dentry);
 				goto out_nfserr;
@@ -498,6 +505,13 @@ __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
 }
 #endif
 
+__be32 nfsd4_clone_file_range(struct file *src, u64 src_pos, struct file *dst,
+		u64 dst_pos, u64 count)
+{
+	return nfserrno(vfs_clone_file_range(src, src_pos, dst, dst_pos,
+			count));
+}
+
 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
 			   struct file *file, loff_t offset, loff_t len,
 			   int flags)
@@ -1809,7 +1823,6 @@ static __be32 nfsd_buffered_readdir(struct file *file, nfsd_filldir_t func,
 	offset = *offsetp;
 
 	while (1) {
-		struct inode *dir_inode = file_inode(file);
 		unsigned int reclen;
 
 		cdp->err = nfserr_eof; /* will be cleared on successful read */
@@ -1828,15 +1841,6 @@ static __be32 nfsd_buffered_readdir(struct file *file, nfsd_filldir_t func,
 		if (!size)
 			break;
 
-		/*
-		 * Various filldir functions may end up calling back into
-		 * lookup_one_len() and the file system's ->lookup() method.
-		 * These expect i_mutex to be held, as it would within readdir.
-		 */
-		host_err = mutex_lock_killable(&dir_inode->i_mutex);
-		if (host_err)
-			break;
-
 		de = (struct buffered_dirent *)buf.dirent;
 		while (size > 0) {
 			offset = de->offset;
@@ -1853,7 +1857,6 @@ static __be32 nfsd_buffered_readdir(struct file *file, nfsd_filldir_t func,
 			size -= reclen;
 			de = (struct buffered_dirent *)((char *)de + reclen);
 		}
-		mutex_unlock(&dir_inode->i_mutex);
 		if (size > 0) /* We bailed out early */
 			break;