lustre/llite/symlink.c

   1 /*
   2  *  linux/fs/ext2/symlink.c
   3  *
   4  * This code is issued under the GNU General Public License.
   5  * See the file COPYING in this distribution
   6  *
   7  * Copyright (C) 1992, 1993, 1994, 1995
   8  * Remy Card (card@masi.ibp.fr)
   9  * Laboratoire MASI - Institut Blaise Pascal
  10  * Universite Pierre et Marie Curie (Paris VI)
  11  *
  12  *  from
  13  *
  14  *  linux/fs/minix/symlink.c
  15  *
  16  *  Copyright (C) 1991, 1992  Linus Torvalds
  17  *
  18  *  ext2 symlink handling code
  19  *
  20  * Modified for OBDFS:
  21  *  Copyright (C) 1999 Seagate Technology Inc. (author: braam@stelias.com)
  22  */
  23
  24 #include <linux/fs.h>
  25 #include <linux/mm.h>
  26 #include <linux/stat.h>
  27 #include <linux/locks.h>
  28 #include <linux/obd_support.h> /* for ENTRY and EXIT only */
  29 #include <linux/lustre_light.h>
  30
  31 static int ll_fast_readlink(struct dentry *dentry, char *buffer, int buflen)
  32 {
  33         char *s = ll_i2info(dentry->d_inode)->lli_inline;
  34         return vfs_readlink(dentry, buffer, buflen, s);
  35 }
  36
  37 static int ll_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
  38 {
  39         char *s = ll_i2info(dentry->d_inode)->lli_inline;
  40         return vfs_follow_link(nd, s);
  41 }
  42
  43 extern int ll_setattr(struct dentry *de, struct iattr *attr);
  44 struct inode_operations ll_fast_symlink_inode_operations = {
  45         readlink:       ll_fast_readlink,
  46         follow_link:    ll_fast_follow_link,
  47         setattr:        ll_setattr
  48 };
  49
  50 static int ll_readlink(struct dentry *dentry, char *buffer, int buflen)
  51 {
  52         struct page *page = NULL;
  53         int res;
  54
  55         ENTRY;
  56         OIDEBUG(dentry->d_inode);
  57         page = ll_getpage(dentry->d_inode, 0, 0, 0);
  58         /* PDEBUG(page, "readlink"); */
  59         if (!page) {
  60                 EXIT;
  61                 return 0;
  62         }
  63         res = vfs_readlink(dentry, buffer, buflen, (char *)page_address(page));
  64         page_cache_release(page);
  65         EXIT;
  66         return res;
  67 } /* ll_readlink */
  68
  69 static int ll_follow_link(struct dentry * dentry,
  70                              struct nameidata *nd)
  71 {
  72         struct page *page = NULL;
  73         int res;
  74
  75         ENTRY;
  76         OIDEBUG(dentry->d_inode);
  77         page = ll_getpage(dentry->d_inode, 0, 0, 0);
  78         /* PDEBUG(page, "follow_link"); */
  79         if (!page) {
  80                 dput(nd->dentry);
  81                 EXIT;
  82                 return -EIO;
  83         }
  84         res = vfs_follow_link(nd, (char *)page_address(page));
  85         page_cache_release(page);
  86         EXIT;
  87         return res;
  88 }
  89
  90 struct inode_operations ll_symlink_inode_operations = {
  91         readlink:       ll_readlink,
  92         follow_link:    ll_follow_link,
  93         setattr:        ll_setattr
  94 };