lustre/obdfs/symlink.c

   1 /*
   2  *  linux/fs/ext2/symlink.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/symlink.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  ext2 symlink handling code
  16  *
  17  * Modified for OBDFS:
  18  *  Copyright (C) 1999 Seagate Technology Inc. (author: braam@stelias.com)
  19  */
  20
  21 #include <linux/fs.h>
  22 #include <linux/ext2_fs.h>
  23 #include <linux/mm.h>
  24 #include <linux/stat.h>
  25 #include <linux/locks.h>
  26 #include <linux/obd_support.h> /* for ENTRY and EXIT only */
  27 #include <linux/obdfs.h>
  28
  29 static int obdfs_fast_readlink(struct dentry *dentry, char *buffer, int buflen)
  30 {
  31         char *s = obdfs_i2info(dentry->d_inode)->oi_inline;
  32         return vfs_readlink(dentry, buffer, buflen, s);
  33 }
  34
  35 static struct dentry *obdfs_fast_follow_link(struct dentry *dentry, struct dentry *base, unsigned flags)
  36 {
  37         char *s = obdfs_i2info(dentry->d_inode)->oi_inline;
  38         return vfs_follow_link(dentry, base, flags, s);
  39 }
  40
  41 struct inode_operations obdfs_fast_symlink_inode_operations = {
  42         readlink:       obdfs_fast_readlink,
  43         follow_link:    obdfs_fast_follow_link,
  44 };
  45
  46 static int obdfs_readlink(struct dentry *dentry, char *buffer, int buflen)
  47 {
  48         struct page *page = NULL;
  49         int res;
  50
  51         ENTRY;
  52         OIDEBUG(dentry->d_inode);
  53         page = obdfs_getpage(dentry->d_inode, 0, 0, 0);
  54         /* PDEBUG(page, "readlink"); */
  55         if (!page) {
  56                 EXIT;
  57                 return 0;
  58         }
  59         res = vfs_readlink(dentry, buffer, buflen, (char *)page_address(page));
  60         page_cache_release(page);
  61         EXIT;
  62         return res;
  63 } /* obdfs_readlink */
  64
  65 static struct dentry * obdfs_follow_link(struct dentry * dentry,
  66                                          struct dentry *base,
  67                                          unsigned int follow)
  68 {
  69         struct page *page = NULL;
  70         struct dentry *res;
  71
  72         ENTRY;
  73         OIDEBUG(dentry->d_inode);
  74         page = obdfs_getpage(dentry->d_inode, 0, 0, 0);
  75         /* PDEBUG(page, "follow_link"); */
  76         if (!page) {
  77                 dput(base);
  78                 EXIT;
  79                 return ERR_PTR(-EIO);
  80         }
  81         res = vfs_follow_link(dentry, base, follow, (char *)page_address(page));
  82         page_cache_release(page);
  83         EXIT;
  84         return res;
  85 }
  86
  87 struct inode_operations obdfs_symlink_inode_operations = {
  88         readlink:       obdfs_readlink,
  89         follow_link:    obdfs_follow_link,
  90 };