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/mm.h>
  23 #include <linux/stat.h>
  24 #include <linux/locks.h>
  25 #include <linux/obd_support.h> /* for ENTRY and EXIT only */
  26 #include <linux/obdfs.h>
  27
  28 static int obdfs_fast_readlink(struct dentry *dentry, char *buffer, int buflen)
  29 {
  30         char *s = obdfs_i2info(dentry->d_inode)->oi_inline;
  31         return vfs_readlink(dentry, buffer, buflen, s);
  32 }
  33
  34 static int obdfs_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
  35 {
  36         char *s = obdfs_i2info(dentry->d_inode)->oi_inline;
  37         return vfs_follow_link(nd, s);
  38 }
  39
  40 struct inode_operations obdfs_fast_symlink_inode_operations = {
  41         readlink:       obdfs_fast_readlink,
  42         follow_link:    obdfs_fast_follow_link,
  43 };
  44
  45 static int obdfs_readlink(struct dentry *dentry, char *buffer, int buflen)
  46 {
  47         struct page *page = NULL;
  48         int res;
  49
  50         ENTRY;
  51         OIDEBUG(dentry->d_inode);
  52         page = obdfs_getpage(dentry->d_inode, 0, 0, 0);
  53         /* PDEBUG(page, "readlink"); */
  54         if (!page) {
  55                 EXIT;
  56                 return 0;
  57         }
  58         res = vfs_readlink(dentry, buffer, buflen, (char *)page_address(page));
  59         page_cache_release(page);
  60         EXIT;
  61         return res;
  62 } /* obdfs_readlink */
  63
  64 static int obdfs_follow_link(struct dentry * dentry,
  65                              struct nameidata *nd)
  66 {
  67         struct page *page = NULL;
  68         int res;
  69
  70         ENTRY;
  71         OIDEBUG(dentry->d_inode);
  72         page = obdfs_getpage(dentry->d_inode, 0, 0, 0);
  73         /* PDEBUG(page, "follow_link"); */
  74         if (!page) {
  75                 dput(nd->dentry);
  76                 EXIT;
  77                 return -EIO;
  78         }
  79         res = vfs_follow_link(nd, (char *)page_address(page));
  80         page_cache_release(page);
  81         EXIT;
  82         return res;
  83 }
  84
  85 struct inode_operations obdfs_symlink_inode_operations = {
  86         readlink:       obdfs_readlink,
  87         follow_link:    obdfs_follow_link,
  88 };