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From:   trondmy@gmail.com
To:     linux-nfs@vger.kernel.org
Subject: [PATCH v3 08/17] NFS: Simplify struct nfs_cache_array_entry
Date:   Wed,  4 Nov 2020 11:16:29 -0500
Message-Id: <20201104161638.300324-9-trond.myklebust@hammerspace.com>
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From: Trond Myklebust <trond.myklebust@hammerspace.com>

We don't need to store a hash, so replace struct qstr with a simple
const char pointer and length.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/dir.c | 46 +++++++++++++++++++++++++---------------------
 1 file changed, 25 insertions(+), 21 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index b9001123ec84..be0e2891fecc 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -133,7 +133,8 @@ nfs_closedir(struct inode *inode, struct file *filp)
 struct nfs_cache_array_entry {
 	u64 cookie;
 	u64 ino;
-	struct qstr string;
+	const char *name;
+	unsigned int name_len;
 	unsigned char d_type;
 };
 
@@ -192,7 +193,7 @@ void nfs_readdir_clear_array(struct page *page)
 
 	array = kmap_atomic(page);
 	for (i = 0; i < array->size; i++)
-		kfree(array->array[i].string.name);
+		kfree(array->array[i].name);
 	nfs_readdir_array_init(array);
 	kunmap_atomic(array);
 }
@@ -213,20 +214,17 @@ static bool nfs_readdir_array_is_full(struct nfs_cache_array *array)
  * when called by nfs_readdir_add_to_array, the strings will be freed in
  * nfs_clear_readdir_array()
  */
-static
-int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
+static const char *nfs_readdir_copy_name(const char *name, unsigned int len)
 {
-	string->len = len;
-	string->name = kmemdup_nul(name, len, GFP_KERNEL);
-	if (string->name == NULL)
-		return -ENOMEM;
+	const char *ret = kmemdup_nul(name, len, GFP_KERNEL);
+
 	/*
 	 * Avoid a kmemleak false positive. The pointer to the name is stored
 	 * in a page cache page which kmemleak does not scan.
 	 */
-	kmemleak_not_leak(string->name);
-	string->hash = full_name_hash(NULL, name, len);
-	return 0;
+	if (ret != NULL)
+		kmemleak_not_leak(ret);
+	return ret;
 }
 
 /*
@@ -249,27 +247,34 @@ static int nfs_readdir_array_can_expand(struct nfs_cache_array *array)
 static
 int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
 {
-	struct nfs_cache_array *array = kmap(page);
+	struct nfs_cache_array *array;
 	struct nfs_cache_array_entry *cache_entry;
+	const char *name;
 	int ret;
 
+	name = nfs_readdir_copy_name(entry->name, entry->len);
+	if (!name)
+		return -ENOMEM;
+
+	array = kmap_atomic(page);
 	ret = nfs_readdir_array_can_expand(array);
-	if (ret)
+	if (ret) {
+		kfree(name);
 		goto out;
+	}
 
 	cache_entry = &array->array[array->size];
 	cache_entry->cookie = entry->prev_cookie;
 	cache_entry->ino = entry->ino;
 	cache_entry->d_type = entry->d_type;
-	ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len);
-	if (ret)
-		goto out;
+	cache_entry->name_len = entry->len;
+	cache_entry->name = name;
 	array->last_cookie = entry->cookie;
 	array->size++;
 	if (entry->eof != 0)
 		nfs_readdir_array_set_eof(array);
 out:
-	kunmap(page);
+	kunmap_atomic(array);
 	return ret;
 }
 
@@ -413,9 +418,8 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des
 					if (printk_ratelimit()) {
 						pr_notice("NFS: directory %pD2 contains a readdir loop."
 								"Please contact your server vendor.  "
-								"The file: %.*s has duplicate cookie %llu\n",
-								desc->file, array->array[i].string.len,
-								array->array[i].string.name, desc->dir_cookie);
+								"The file: %s has duplicate cookie %llu\n",
+								desc->file, array->array[i].name, desc->dir_cookie);
 					}
 					status = -ELOOP;
 					goto out;
@@ -888,7 +892,7 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc)
 		struct nfs_cache_array_entry *ent;
 
 		ent = &array->array[i];
-		if (!dir_emit(desc->ctx, ent->string.name, ent->string.len,
+		if (!dir_emit(desc->ctx, ent->name, ent->name_len,
 		    nfs_compat_user_ino64(ent->ino), ent->d_type)) {
 			desc->eof = true;
 			break;
-- 
2.28.0