Switch !O_CREAT case to use of do_last()
Al Viro [Sat, 26 Dec 2009 15:56:19 +0000 (10:56 -0500)]
... and now we have all intents crap well localized

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/namei.c

index 1f5d86d..9a64560 100644 (file)
@@ -1359,22 +1359,6 @@ static inline int may_create(struct inode *dir, struct dentry *child)
        return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 }
 
-/* 
- * O_DIRECTORY translates into forcing a directory lookup.
- */
-static inline int lookup_flags(unsigned int f)
-{
-       unsigned long retval = LOOKUP_FOLLOW;
-
-       if (f & O_NOFOLLOW)
-               retval &= ~LOOKUP_FOLLOW;
-       
-       if (f & O_DIRECTORY)
-               retval |= LOOKUP_DIRECTORY;
-
-       return retval;
-}
-
 /*
  * p1 and p2 should be directories on the same fs.
  */
@@ -1631,19 +1615,60 @@ exit:
 
 static struct file *do_last(struct nameidata *nd, struct path *path,
                            int open_flag, int acc_mode,
-                           int mode, const char *pathname)
+                           int mode, const char *pathname,
+                           int *want_dir)
 {
        struct dentry *dir = nd->path.dentry;
        struct file *filp;
-       int error;
+       int error = -EISDIR;
 
-       if (nd->last_type == LAST_BIND)
+       switch (nd->last_type) {
+       case LAST_DOTDOT:
+               follow_dotdot(nd);
+               dir = nd->path.dentry;
+               if (nd->path.mnt->mnt_sb->s_type->fs_flags & FS_REVAL_DOT) {
+                       if (!dir->d_op->d_revalidate(dir, nd)) {
+                               error = -ESTALE;
+                               goto exit;
+                       }
+               }
+               /* fallthrough */
+       case LAST_DOT:
+       case LAST_ROOT:
+               if (open_flag & O_CREAT)
+                       goto exit;
+               /* fallthrough */
+       case LAST_BIND:
+               audit_inode(pathname, dir);
                goto ok;
+       }
 
-       error = -EISDIR;
-       if (nd->last_type != LAST_NORM || nd->last.name[nd->last.len])
-               goto exit;
+       /* trailing slashes? */
+       if (nd->last.name[nd->last.len]) {
+               if (open_flag & O_CREAT)
+                       goto exit;
+               *want_dir = 1;
+       }
 
+       /* just plain open? */
+       if (!(open_flag & O_CREAT)) {
+               error = do_lookup(nd, &nd->last, path);
+               if (error)
+                       goto exit;
+               error = -ENOENT;
+               if (!path->dentry->d_inode)
+                       goto exit_dput;
+               if (path->dentry->d_inode->i_op->follow_link)
+                       return NULL;
+               error = -ENOTDIR;
+               if (*want_dir & !path->dentry->d_inode->i_op->lookup)
+                       goto exit_dput;
+               path_to_nameidata(path, nd);
+               audit_inode(pathname, nd->path.dentry);
+               goto ok;
+       }
+
+       /* OK, it's O_CREAT */
        mutex_lock(&dir->d_inode->i_mutex);
 
        path->dentry = lookup_hash(nd);
@@ -1746,6 +1771,10 @@ struct file *do_filp_open(int dfd, const char *pathname,
        int count = 0;
        int flag = open_to_namei_flags(open_flag);
        int force_reval = 0;
+       int want_dir = open_flag & O_DIRECTORY;
+
+       if (!(open_flag & O_CREAT))
+               mode = 0;
 
        /*
         * O_SYNC is implemented as __O_SYNC|O_DSYNC.  As many places only
@@ -1768,35 +1797,7 @@ struct file *do_filp_open(int dfd, const char *pathname,
        if (open_flag & O_APPEND)
                acc_mode |= MAY_APPEND;
 
-       /*
-        * The simplest case - just a plain lookup.
-        */
-       if (!(open_flag & O_CREAT)) {
-               filp = get_empty_filp();
-
-               if (filp == NULL)
-                       return ERR_PTR(-ENFILE);
-               nd.intent.open.file = filp;
-               filp->f_flags = open_flag;
-               nd.intent.open.flags = flag;
-               nd.intent.open.create_mode = 0;
-               error = do_path_lookup(dfd, pathname,
-                                       lookup_flags(open_flag)|LOOKUP_OPEN, &nd);
-               if (IS_ERR(nd.intent.open.file)) {
-                       if (error == 0) {
-                               error = PTR_ERR(nd.intent.open.file);
-                               path_put(&nd.path);
-                       }
-               } else if (error)
-                       release_open_intent(&nd);
-               if (error)
-                       return ERR_PTR(error);
-               return finish_open(&nd, open_flag, acc_mode);
-       }
-
-       /*
-        * Create - we need to know the parent.
-        */
+       /* find the parent */
 reval:
        error = path_init(dfd, pathname, LOOKUP_PARENT, &nd);
        if (error)
@@ -1810,7 +1811,7 @@ reval:
                filp = ERR_PTR(error);
                goto out;
        }
-       if (unlikely(!audit_dummy_context()))
+       if (unlikely(!audit_dummy_context()) && (open_flag & O_CREAT))
                audit_inode(pathname, nd.path.dentry);
 
        /*
@@ -1826,16 +1827,22 @@ reval:
        nd.intent.open.flags = flag;
        nd.intent.open.create_mode = mode;
        nd.flags &= ~LOOKUP_PARENT;
-       nd.flags |= LOOKUP_CREATE | LOOKUP_OPEN;
-       if (open_flag & O_EXCL)
-               nd.flags |= LOOKUP_EXCL;
-       filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
+       nd.flags |= LOOKUP_OPEN;
+       if (open_flag & O_CREAT) {
+               nd.flags |= LOOKUP_CREATE;
+               if (open_flag & O_EXCL)
+                       nd.flags |= LOOKUP_EXCL;
+       }
+       filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname, &want_dir);
        while (unlikely(!filp)) { /* trailing symlink */
                struct path holder;
-               struct inode *inode;
+               struct inode *inode = path.dentry->d_inode;
                void *cookie;
                error = -ELOOP;
-               if ((open_flag & O_NOFOLLOW) || count++ == 32)
+               /* S_ISDIR part is a temporary automount kludge */
+               if ((open_flag & O_NOFOLLOW) && !S_ISDIR(inode->i_mode))
+                       goto exit_dput;
+               if (count++ == 32)
                        goto exit_dput;
                /*
                 * This is subtle. Instead of calling do_follow_link() we do
@@ -1855,7 +1862,6 @@ reval:
                error = __do_follow_link(&path, &nd, &cookie);
                if (unlikely(error)) {
                        /* nd.path had been dropped */
-                       inode = path.dentry->d_inode;
                        if (!IS_ERR(cookie) && inode->i_op->put_link)
                                inode->i_op->put_link(path.dentry, &nd, cookie);
                        path_put(&path);
@@ -1865,8 +1871,7 @@ reval:
                }
                holder = path;
                nd.flags &= ~LOOKUP_PARENT;
-               filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
-               inode = holder.dentry->d_inode;
+               filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname, &want_dir);
                if (inode->i_op->put_link)
                        inode->i_op->put_link(holder.dentry, &nd, cookie);
                path_put(&holder);