From cc314eef0128a807e50fa03baf2d0abc0647952c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 19 Aug 2005 18:02:56 -0700 Subject: Fix nasty ncpfs symlink handling bug. This bug could cause oopses and page state corruption, because ncpfs used the generic page-cache symlink handlign functions. But those functions only work if the page cache is guaranteed to be "stable", ie a page that was installed when the symlink walk was started has to still be installed in the page cache at the end of the walk. We could have fixed ncpfs to not use the generic helper routines, but it is in many ways much cleaner to instead improve on the symlink walking helper routines so that they don't require that absolute stability. We do this by allowing "follow_link()" to return a error-pointer as a cookie, which is fed back to the cleanup "put_link()" routine. This also simplifies NFS symlink handling. Signed-off-by: Linus Torvalds --- fs/cifs/cifsfs.h | 4 ++-- fs/cifs/link.c | 6 +++--- 2 files changed, 5 insertions(+), 5 deletions(-) (limited to 'fs/cifs') diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h index 78af585..1fd21f6 100644 --- a/fs/cifs/cifsfs.h +++ b/fs/cifs/cifsfs.h @@ -83,8 +83,8 @@ extern int cifs_dir_notify(struct file *, unsigned long arg); extern struct dentry_operations cifs_dentry_ops; /* Functions related to symlinks */ -extern int cifs_follow_link(struct dentry *direntry, struct nameidata *nd); -extern void cifs_put_link(struct dentry *direntry, struct nameidata *nd); +extern void *cifs_follow_link(struct dentry *direntry, struct nameidata *nd); +extern void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *); extern int cifs_readlink(struct dentry *direntry, char __user *buffer, int buflen); extern int cifs_symlink(struct inode *inode, struct dentry *direntry, diff --git a/fs/cifs/link.c b/fs/cifs/link.c index bde0fab..ab925ef 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -92,7 +92,7 @@ cifs_hl_exit: return rc; } -int +void * cifs_follow_link(struct dentry *direntry, struct nameidata *nd) { struct inode *inode = direntry->d_inode; @@ -148,7 +148,7 @@ out: out_no_free: FreeXid(xid); nd_set_link(nd, target_path); - return 0; + return NULL; /* No cookie */ } int @@ -330,7 +330,7 @@ cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen) return rc; } -void cifs_put_link(struct dentry *direntry, struct nameidata *nd) +void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie) { char *p = nd_get_link(nd); if (!IS_ERR(p)) -- cgit v1.1