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  * Re-written Oct 2001.
  22  *
  23  *  Copyright (C) 2001 Cluster File Systems, Inc. (author: braam@clusterfs.com)
  24  */
  25
  26 #include <linux/fs.h>
  27 #include <linux/mm.h>
  28 #include <linux/stat.h>
  29 #include <linux/locks.h>
  30
  31 #define DEBUG_SUBSYSTEM S_OBDFS
  32
  33 #include <linux/obd_support.h> /* for ENTRY and EXIT only */
  34 #include <linux/obdfs.h>
  35
  36 static int obdfs_fast_readlink(struct dentry *dentry, char *buffer, int buflen)
  37 {
  38         char *s = obdfs_i2info(dentry->d_inode)->oi_inline;
  39         return vfs_readlink(dentry, buffer, buflen, s);
  40 }
  41
  42 static int obdfs_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
  43 {
  44         char *s = obdfs_i2info(dentry->d_inode)->oi_inline;
  45         return vfs_follow_link(nd, s);
  46 }
  47
  48 extern int obdfs_setattr(struct dentry *de, struct iattr *attr);
  49 struct inode_operations obdfs_fast_symlink_inode_operations = {
  50         readlink:       obdfs_fast_readlink,
  51         follow_link:    obdfs_fast_follow_link,
  52         setattr:        obdfs_setattr
  53 };
  54
  55 static int obdfs_readlink(struct dentry *dentry, char *buffer, int buflen)
  56 {
  57         struct page *page = NULL;
  58         int res;
  59
  60         ENTRY;
  61         OIDEBUG(dentry->d_inode);
  62         page = obdfs_getpage(dentry->d_inode, 0, 0, 0);
  63         /* PDEBUG(page, "readlink"); */
  64         if (!page) {
  65                 EXIT;
  66                 return 0;
  67         }
  68         res = vfs_readlink(dentry, buffer, buflen, (char *)page_address(page));
  69         page_cache_release(page);
  70         EXIT;
  71         return res;
  72 } /* obdfs_readlink */
  73
  74 static int obdfs_follow_link(struct dentry * dentry,
  75                              struct nameidata *nd)
  76 {
  77         struct page *page = NULL;
  78         int res;
  79
  80         ENTRY;
  81         OIDEBUG(dentry->d_inode);
  82         page = obdfs_getpage(dentry->d_inode, 0, 0, 0);
  83         /* PDEBUG(page, "follow_link"); */
  84         if (!page) {
  85                 dput(nd->dentry);
  86                 EXIT;
  87                 return -EIO;
  88         }
  89         res = vfs_follow_link(nd, (char *)page_address(page));
  90         page_cache_release(page);
  91         EXIT;
  92         return res;
  93 }
  94
  95 struct inode_operations obdfs_symlink_inode_operations = {
  96         readlink:       obdfs_readlink,
  97         follow_link:    obdfs_follow_link,
  98         setattr:        obdfs_setattr
  99 };