Merge branch 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs RCU symlink updates from Al Viro:
 "Replacement of ->follow_link/->put_link, allowing to stay in RCU mode
  even if the symlink is not an embedded one.

  No changes since the mailbomb on Jan 1"

* 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch ->get_link() to delayed_call, kill ->put_link()
  kill free_page_put_link()
  teach nfs_get_link() to work in RCU mode
  teach proc_self_get_link()/proc_thread_self_get_link() to work in RCU mode
  teach shmem_get_link() to work in RCU mode
  teach page_get_link() to work in RCU mode
  replace ->follow_link() with new method that could stay in RCU mode
  don't put symlink bodies in pagecache into highmem
  namei: page_getlink() and page_follow_link_light() are the same thing
  ufs: get rid of ->setattr() for symlinks
  udf: don't duplicate page_symlink_inode_operations
  logfs: don't duplicate page_symlink_inode_operations
  switch befs long symlinks to page_symlink_operations

3 files changed, 16 insertions, 15 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index ea433a7f4bca..b3bd912df6bf 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4283,6 +4283,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 			inode->i_op = &ext4_symlink_inode_operations;
 			ext4_set_aops(inode);
 		}
+		inode_nohighmem(inode);
 	} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 	      S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 		inode->i_op = &ext4_special_inode_operations;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a969ab39f302..f27e0c2598c5 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3132,6 +3132,7 @@ static int ext4_symlink(struct inode *dir,
 	if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
 		if (!encryption_required)
 			inode->i_op = &ext4_symlink_inode_operations;
+		inode_nohighmem(inode);
 		ext4_set_aops(inode);
 		/*
 		 * We cannot call page_symlink() with transaction started
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index e8e7af62ac95..6f7ee30a89ce 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -23,17 +23,21 @@
 #include "xattr.h"
 
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-static const char *ext4_encrypted_follow_link(struct dentry *dentry, void **cookie)
+static const char *ext4_encrypted_get_link(struct dentry *dentry,
+					   struct inode *inode,
+					   struct delayed_call *done)
 {
 	struct page *cpage = NULL;
 	char *caddr, *paddr = NULL;
 	struct ext4_str cstr, pstr;
-	struct inode *inode = d_inode(dentry);
 	struct ext4_encrypted_symlink_data *sd;
 	loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
 	int res;
 	u32 plen, max_size = inode->i_sb->s_blocksize;
 
+	if (!dentry)
+		return ERR_PTR(-ECHILD);
+
 	res = ext4_get_encryption_info(inode);
 	if (res)
 		return ERR_PTR(res);
@@ -45,7 +49,7 @@ static const char *ext4_encrypted_follow_link(struct dentry *dentry, void **cook
 		cpage = read_mapping_page(inode->i_mapping, 0, NULL);
 		if (IS_ERR(cpage))
 			return ERR_CAST(cpage);
-		caddr = kmap(cpage);
+		caddr = page_address(cpage);
 		caddr[size] = 0;
 	}
 
@@ -75,24 +79,20 @@ static const char *ext4_encrypted_follow_link(struct dentry *dentry, void **cook
 	/* Null-terminate the name */
 	if (res <= plen)
 		paddr[res] = '\0';
-	if (cpage) {
-		kunmap(cpage);
+	if (cpage)
 		page_cache_release(cpage);
-	}
-	return *cookie = paddr;
+	set_delayed_call(done, kfree_link, paddr);
+	return paddr;
 errout:
-	if (cpage) {
-		kunmap(cpage);
+	if (cpage)
 		page_cache_release(cpage);
-	}
 	kfree(paddr);
 	return ERR_PTR(res);
 }
 
 const struct inode_operations ext4_encrypted_symlink_inode_operations = {
 	.readlink	= generic_readlink,
-	.follow_link    = ext4_encrypted_follow_link,
-	.put_link       = kfree_put_link,
+	.get_link	= ext4_encrypted_get_link,
 	.setattr	= ext4_setattr,
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
@@ -103,8 +103,7 @@ const struct inode_operations ext4_encrypted_symlink_inode_operations = {
 
 const struct inode_operations ext4_symlink_inode_operations = {
 	.readlink	= generic_readlink,
-	.follow_link	= page_follow_link_light,
-	.put_link	= page_put_link,
+	.get_link	= page_get_link,
 	.setattr	= ext4_setattr,
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
@@ -114,7 +113,7 @@ const struct inode_operations ext4_symlink_inode_operations = {
 
 const struct inode_operations ext4_fast_symlink_inode_operations = {
 	.readlink	= generic_readlink,
-	.follow_link    = simple_follow_link,
+	.get_link	= simple_get_link,
 	.setattr	= ext4_setattr,
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,