From: <viro@parcelfarce.linux.theplanet.co.uk>
ext2 conversion (helper functions for that one will be actually used a lot by
other filesystems, so to fs/namei.c they go)
---
25-akpm/fs/ext2/symlink.c | 17 +++++----------
25-akpm/fs/namei.c | 49 +++++++++++++++++++++++++++++++++++++++++++--
25-akpm/include/linux/fs.h | 3 ++
3 files changed, 56 insertions(+), 13 deletions(-)
diff -puN fs/ext2/symlink.c~SL1-ext2-RC6-bk5 fs/ext2/symlink.c
--- 25/fs/ext2/symlink.c~SL1-ext2-RC6-bk5 2004-05-19 20:49:57.991492856 -0700
+++ 25-akpm/fs/ext2/symlink.c 2004-05-19 20:49:57.997491944 -0700
@@ -20,22 +20,17 @@
#include "ext2.h"
#include "xattr.h"
-static int
-ext2_readlink(struct dentry *dentry, char __user *buffer, int buflen)
-{
- struct ext2_inode_info *ei = EXT2_I(dentry->d_inode);
- return vfs_readlink(dentry, buffer, buflen, (char *)ei->i_data);
-}
-
static int ext2_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct ext2_inode_info *ei = EXT2_I(dentry->d_inode);
- return vfs_follow_link(nd, (char *)ei->i_data);
+ nd_set_link(nd, (char *)ei->i_data);
+ return 0;
}
struct inode_operations ext2_symlink_inode_operations = {
- .readlink = page_readlink,
- .follow_link = page_follow_link,
+ .readlink = generic_readlink,
+ .follow_link = page_follow_link_light,
+ .put_link = page_put_link,
.setxattr = ext2_setxattr,
.getxattr = ext2_getxattr,
.listxattr = ext2_listxattr,
@@ -43,7 +38,7 @@ struct inode_operations ext2_symlink_ino
};
struct inode_operations ext2_fast_symlink_inode_operations = {
- .readlink = ext2_readlink,
+ .readlink = generic_readlink,
.follow_link = ext2_follow_link,
.setxattr = ext2_setxattr,
.getxattr = ext2_getxattr,
diff -puN fs/namei.c~SL1-ext2-RC6-bk5 fs/namei.c
--- 25/fs/namei.c~SL1-ext2-RC6-bk5 2004-05-19 20:49:57.993492552 -0700
+++ 25-akpm/fs/namei.c 2004-05-19 20:49:57.999491640 -0700
@@ -2192,6 +2192,23 @@ out:
return len;
}
+/*
+ * A helper for ->readlink(). This should be used *ONLY* for symlinks that
+ * have ->follow_link() touching nd only in nd_set_link(). Using (or not
+ * using) it for any given inode is up to filesystem.
+ */
+int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
+{
+ struct nameidata nd;
+ int res = dentry->d_inode->i_op->follow_link(dentry, &nd);
+ if (!res) {
+ res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd));
+ if (dentry->d_inode->i_op->put_link)
+ dentry->d_inode->i_op->put_link(dentry, &nd);
+ }
+ return res;
+}
+
static inline int
__vfs_follow_link(struct nameidata *nd, const char *link)
{
@@ -2268,6 +2285,30 @@ int page_readlink(struct dentry *dentry,
return res;
}
+int page_follow_link_light(struct dentry *dentry, struct nameidata *nd)
+{
+ struct page *page;
+ char *s = page_getlink(dentry, &page);
+ if (!IS_ERR(s)) {
+ nd_set_link(nd, s);
+ s = NULL;
+ }
+ return PTR_ERR(s);
+}
+
+void page_put_link(struct dentry *dentry, struct nameidata *nd)
+{
+ if (!IS_ERR(nd_get_link(nd))) {
+ struct page *page;
+ page = find_get_page(dentry->d_inode->i_mapping, 0);
+ if (!page)
+ BUG();
+ kunmap(page);
+ page_cache_release(page);
+ page_cache_release(page);
+ }
+}
+
int page_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct page *page = NULL;
@@ -2322,8 +2363,9 @@ fail:
}
struct inode_operations page_symlink_inode_operations = {
- .readlink = page_readlink,
- .follow_link = page_follow_link,
+ .readlink = generic_readlink,
+ .follow_link = page_follow_link_light,
+ .put_link = page_put_link,
};
EXPORT_SYMBOL(__user_walk);
@@ -2336,6 +2378,8 @@ EXPORT_SYMBOL(lookup_create);
EXPORT_SYMBOL(lookup_hash);
EXPORT_SYMBOL(lookup_one_len);
EXPORT_SYMBOL(page_follow_link);
+EXPORT_SYMBOL(page_follow_link_light);
+EXPORT_SYMBOL(page_put_link);
EXPORT_SYMBOL(page_readlink);
EXPORT_SYMBOL(page_symlink);
EXPORT_SYMBOL(page_symlink_inode_operations);
@@ -2355,3 +2399,4 @@ EXPORT_SYMBOL(vfs_rename);
EXPORT_SYMBOL(vfs_rmdir);
EXPORT_SYMBOL(vfs_symlink);
EXPORT_SYMBOL(vfs_unlink);
+EXPORT_SYMBOL(generic_readlink);
diff -puN include/linux/fs.h~SL1-ext2-RC6-bk5 include/linux/fs.h
--- 25/include/linux/fs.h~SL1-ext2-RC6-bk5 2004-05-19 20:49:57.995492248 -0700
+++ 25-akpm/include/linux/fs.h 2004-05-19 20:49:58.010489968 -0700
@@ -1468,8 +1468,11 @@ extern int vfs_readlink(struct dentry *,
extern int vfs_follow_link(struct nameidata *, const char *);
extern int page_readlink(struct dentry *, char __user *, int);
extern int page_follow_link(struct dentry *, struct nameidata *);
+extern int page_follow_link_light(struct dentry *, struct nameidata *);
+extern void page_put_link(struct dentry *, struct nameidata *);
extern int page_symlink(struct inode *inode, const char *symname, int len);
extern struct inode_operations page_symlink_inode_operations;
+extern int generic_readlink(struct dentry *, char __user *, int);
extern void generic_fillattr(struct inode *, struct kstat *);
extern int vfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
void inode_add_bytes(struct inode *inode, loff_t bytes);
_