From: NeilBrown <neil@brown.name>
Date: Sun, 8 Jun 2025 22:15:17 +0000 (+1000)
Subject: nfs: use lock_two_nondirectories()
X-Git-Tag: io_uring-6.17-20250815~23^2~40
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=c1b0b9d79fdf8a86451eac914fe6f5cf39bbfc5f;p=linux-block.git

nfs: use lock_two_nondirectories()

Rather than open-coding this function call it to make intention clear
and to use "correct" nesting levels (parent and child are for
directories).

This is purely cosmetic with no expected change in behaviour.

Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/r/174942091741.608730.3327223511347232829@noble.neil.brown.name
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---

diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 5e9d66f3466c..53a958746bb0 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -253,7 +253,6 @@ static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
 	struct nfs_server *server = NFS_SERVER(dst_inode);
 	struct inode *src_inode = file_inode(src_file);
 	unsigned int bs = server->clone_blksize;
-	bool same_inode = false;
 	int ret;
 
 	/* NFS does not support deduplication. */
@@ -275,20 +274,8 @@ static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
 			goto out;
 	}
 
-	if (src_inode == dst_inode)
-		same_inode = true;
-
 	/* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
-	if (same_inode) {
-		inode_lock(src_inode);
-	} else if (dst_inode < src_inode) {
-		inode_lock_nested(dst_inode, I_MUTEX_PARENT);
-		inode_lock_nested(src_inode, I_MUTEX_CHILD);
-	} else {
-		inode_lock_nested(src_inode, I_MUTEX_PARENT);
-		inode_lock_nested(dst_inode, I_MUTEX_CHILD);
-	}
-
+	lock_two_nondirectories(src_inode, dst_inode);
 	/* flush all pending writes on both src and dst so that server
 	 * has the latest data */
 	ret = nfs_sync_inode(src_inode);
@@ -306,15 +293,7 @@ static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
 		truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
 
 out_unlock:
-	if (same_inode) {
-		inode_unlock(src_inode);
-	} else if (dst_inode < src_inode) {
-		inode_unlock(src_inode);
-		inode_unlock(dst_inode);
-	} else {
-		inode_unlock(dst_inode);
-		inode_unlock(src_inode);
-	}
+	unlock_two_nondirectories(src_inode, dst_inode);
 out:
 	return ret < 0 ? ret : count;
 }