X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fnfs%2Fsymlink.c;h=35f1065991441c3f3d02f6749692da739b8492b3;hb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;hp=fabadfbfd47ea43890cfb30df05b48ec16174564;hpb=a2c21200f1c81b08cb55e417b68150bba439b646;p=linux-2.6.git

diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
index fabadfbfd..35f106599 100644
--- a/fs/nfs/symlink.c
+++ b/fs/nfs/symlink.c
@@ -23,20 +23,30 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/smp_lock.h>
+#include <linux/namei.h>
 
 /* Symlink caching in the page cache is even more simplistic
  * and straight-forward than readdir caching.
+ *
+ * At the beginning of the page we store pointer to struct page in question,
+ * simplifying nfs_put_link() (if inode got invalidated we can't find the page
+ * to be freed via pagecache lookup).
+ * The NUL-terminated string follows immediately thereafter.
  */
+
+struct nfs_symlink {
+	struct page *page;
+	char body[0];
+};
+
 static int nfs_symlink_filler(struct inode *inode, struct page *page)
 {
+	const unsigned int pgbase = offsetof(struct nfs_symlink, body);
+	const unsigned int pglen = PAGE_SIZE - pgbase;
 	int error;
 
-	/* We place the length at the beginning of the page,
-	 * in host byte order, followed by the string.  The
-	 * XDR response verification will NULL terminate it.
-	 */
 	lock_kernel();
-	error = NFS_PROTO(inode)->readlink(inode, page);
+	error = NFS_PROTO(inode)->readlink(inode, page, pgbase, pglen);
 	unlock_kernel();
 	if (error < 0)
 		goto error;
@@ -50,61 +60,58 @@ error:
 	return -EIO;
 }
 
-static char *nfs_getlink(struct inode *inode, struct page **ppage)
+static int nfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
+	struct inode *inode = dentry->d_inode;
 	struct page *page;
-	u32 *p;
-
-	page = ERR_PTR(nfs_revalidate_inode(NFS_SERVER(inode), inode));
-	if (page)
+	struct nfs_symlink *p;
+	void *err = ERR_PTR(nfs_revalidate_inode(NFS_SERVER(inode), inode));
+	if (err)
 		goto read_failed;
 	page = read_cache_page(&inode->i_data, 0,
 				(filler_t *)nfs_symlink_filler, inode);
-	if (IS_ERR(page))
+	if (IS_ERR(page)) {
+		err = page;
 		goto read_failed;
-	if (!PageUptodate(page))
+	}
+	if (!PageUptodate(page)) {
+		err = ERR_PTR(-EIO);
 		goto getlink_read_error;
-	*ppage = page;
+	}
 	p = kmap(page);
-	return (char*)(p+1);
+	p->page = page;
+	nd_set_link(nd, p->body);
+	return 0;
 
 getlink_read_error:
 	page_cache_release(page);
-	page = ERR_PTR(-EIO);
 read_failed:
-	return (char*)page;
+	nd_set_link(nd, err);
+	return 0;
 }
 
-static int nfs_readlink(struct dentry *dentry, char __user *buffer, int buflen)
+static void nfs_put_link(struct dentry *dentry, struct nameidata *nd)
 {
-	struct inode *inode = dentry->d_inode;
-	struct page *page = NULL;
-	int res = vfs_readlink(dentry,buffer,buflen,nfs_getlink(inode,&page));
-	if (page) {
-		kunmap(page);
-		page_cache_release(page);
-	}
-	return res;
-}
+	char *s = nd_get_link(nd);
+	if (!IS_ERR(s)) {
+		struct nfs_symlink *p;
+		struct page *page;
+
+		p = container_of(s, struct nfs_symlink, body[0]);
+		page = p->page;
 
-static int nfs_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
-	struct inode *inode = dentry->d_inode;
-	struct page *page = NULL;
-	int res = vfs_follow_link(nd, nfs_getlink(inode,&page));
-	if (page) {
 		kunmap(page);
 		page_cache_release(page);
 	}
-	return res;
 }
 
 /*
  * symlinks can't do much...
  */
 struct inode_operations nfs_symlink_inode_operations = {
-	.readlink	= nfs_readlink,
+	.readlink	= generic_readlink,
 	.follow_link	= nfs_follow_link,
+	.put_link	= nfs_put_link,
 	.getattr	= nfs_getattr,
 	.setattr	= nfs_setattr,
 };