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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH 05/13] namei: page_getlink() and page_follow_link_light() are the same thing
Date: Fri,  1 Jan 2016 06:38:13 +0000	[thread overview]
Message-ID: <1451630301-30618-5-git-send-email-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20160101063624.GG9938@ZenIV.linux.org.uk>

From: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/namei.c | 32 +++++++++++++-------------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 0c3974c..4bae5cb 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4518,7 +4518,7 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 EXPORT_SYMBOL(generic_readlink);
 
 /* get the link contents into pagecache */
-static char *page_getlink(struct dentry * dentry, struct page **ppage)
+static const char *page_getlink(struct dentry * dentry, void **cookie)
 {
 	char *kaddr;
 	struct page *page;
@@ -4526,31 +4526,15 @@ static char *page_getlink(struct dentry * dentry, struct page **ppage)
 	page = read_mapping_page(mapping, 0, NULL);
 	if (IS_ERR(page))
 		return (char*)page;
-	*ppage = page;
+	*cookie = page;
 	kaddr = kmap(page);
 	nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1);
 	return kaddr;
 }
 
-int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
-{
-	struct page *page = NULL;
-	int res = readlink_copy(buffer, buflen, page_getlink(dentry, &page));
-	if (page) {
-		kunmap(page);
-		page_cache_release(page);
-	}
-	return res;
-}
-EXPORT_SYMBOL(page_readlink);
-
 const char *page_follow_link_light(struct dentry *dentry, void **cookie)
 {
-	struct page *page = NULL;
-	char *res = page_getlink(dentry, &page);
-	if (!IS_ERR(res))
-		*cookie = page;
-	return res;
+	return page_getlink(dentry, cookie);
 }
 EXPORT_SYMBOL(page_follow_link_light);
 
@@ -4562,6 +4546,16 @@ void page_put_link(struct inode *unused, void *cookie)
 }
 EXPORT_SYMBOL(page_put_link);
 
+int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
+{
+	void *cookie = NULL;
+	int res = readlink_copy(buffer, buflen, page_getlink(dentry, &cookie));
+	if (cookie)
+		page_put_link(NULL, cookie);
+	return res;
+}
+EXPORT_SYMBOL(page_readlink);
+
 /*
  * The nofs argument instructs pagecache_write_begin to pass AOP_FLAG_NOFS
  */
-- 
2.1.4


  parent reply	other threads:[~2016-01-01  6:38 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-01  6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
2016-01-01  6:38 ` [PATCH 01/13] switch befs long symlinks to page_symlink_operations Al Viro
2016-01-01  6:38 ` [PATCH 02/13] logfs: don't duplicate page_symlink_inode_operations Al Viro
2016-01-01  6:38 ` [PATCH 03/13] udf: " Al Viro
2016-01-05 16:27   ` Jan Kara
2016-01-01  6:38 ` [PATCH 04/13] ufs: get rid of ->setattr() for symlinks Al Viro
2016-01-01  6:38 ` Al Viro [this message]
2016-01-01  6:38 ` [PATCH 06/13] don't put symlink bodies in pagecache into highmem Al Viro
2016-01-01  6:38 ` [PATCH 07/13] replace ->follow_link() with new method that could stay in RCU mode Al Viro
2016-01-01  6:38 ` [PATCH 08/13] teach page_get_link() to work " Al Viro
2016-01-01  6:38 ` [PATCH 09/13] teach shmem_get_link() " Al Viro
2016-01-01  6:38 ` [PATCH 10/13] teach proc_self_get_link()/proc_thread_self_get_link() " Al Viro
2016-01-01  6:38 ` [PATCH 11/13] teach nfs_get_link() " Al Viro
2016-01-01  6:38 ` [PATCH 12/13] kill free_page_put_link() Al Viro
2016-01-01  6:38 ` [PATCH 13/13] switch ->get_link() to delayed_call, kill ->put_link() Al Viro
2016-01-03 19:53 ` [RFC] ->get_link(), ->put_link() and cookies Linus Torvalds
2016-01-03 20:21   ` Al Viro
2016-01-03 20:41     ` Linus Torvalds
2016-01-03 21:40       ` Al Viro

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