lustre/obdfs/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/obdfs.h>
  30
  31 static int obdfs_fast_readlink(struct dentry *dentry, char *buffer, int buflen)
  32 {
  33         char *s = obdfs_i2info(dentry->d_inode)->oi_inline;
  34         return vfs_readlink(dentry, buffer, buflen, s);
  35 }
  36
  37 static int obdfs_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
  38 {
  39         char *s = obdfs_i2info(dentry->d_inode)->oi_inline;
  40         return vfs_follow_link(nd, s);
  41 }
  42
  43 struct inode_operations obdfs_fast_symlink_inode_operations = {
  44         readlink:       obdfs_fast_readlink,
  45         follow_link:    obdfs_fast_follow_link,
  46 };
  47
  48 static int obdfs_readlink(struct dentry *dentry, char *buffer, int buflen)
  49 {
  50         struct page *page = NULL;
  51         int res;
  52
  53         ENTRY;
  54         OIDEBUG(dentry->d_inode);
  55         page = obdfs_getpage(dentry->d_inode, 0, 0, 0);
  56         /* PDEBUG(page, "readlink"); */
  57         if (!page) {
  58                 EXIT;
  59                 return 0;
  60         }
  61         res = vfs_readlink(dentry, buffer, buflen, (char *)page_address(page));
  62         page_cache_release(page);
  63         EXIT;
  64         return res;
  65 } /* obdfs_readlink */
  66
  67 static int obdfs_follow_link(struct dentry * dentry,
  68                              struct nameidata *nd)
  69 {
  70         struct page *page = NULL;
  71         int res;
  72
  73         ENTRY;
  74         OIDEBUG(dentry->d_inode);
  75         page = obdfs_getpage(dentry->d_inode, 0, 0, 0);
  76         /* PDEBUG(page, "follow_link"); */
  77         if (!page) {
  78                 dput(nd->dentry);
  79                 EXIT;
  80                 return -EIO;
  81         }
  82         res = vfs_follow_link(nd, (char *)page_address(page));
  83         page_cache_release(page);
  84         EXIT;
  85         return res;
  86 }
  87
  88 struct inode_operations obdfs_symlink_inode_operations = {
  89         readlink:       obdfs_readlink,
  90         follow_link:    obdfs_follow_link,
  91 };