fs/nfs/symlink.c

/* */
This source file includes following definitions.
nfs_follow_link
nfs_readlink
   1 /*
   2  *  linux/fs/nfs/symlink.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  *
   6  *  Optimization changes Copyright (C) 1994 Florian La Roche
   7  *
   8  *  nfs symlink handling code
   9  */
  10 
  11 #ifdef MODULE
  12 #include <linux/module.h>
  13 #endif
  14 
  15 #include <asm/segment.h>
  16 
  17 #include <linux/sched.h>
  18 #include <linux/errno.h>
  19 #include <linux/nfs_fs.h>
  20 #include <linux/stat.h>
  21 #include <linux/mm.h>
  22 #include <linux/malloc.h>
  23 #include <linux/string.h>
  24 
  25 static int nfs_readlink(struct inode *, char *, int);
  26 static int nfs_follow_link(struct inode *, struct inode *, int, int,
  27                            struct inode **);
  28 
  29 /*
  30  * symlinks can't do much...
  31  */
  32 struct inode_operations nfs_symlink_inode_operations = {
  33         NULL,                   /* no file-operations */
  34         NULL,                   /* create */
  35         NULL,                   /* lookup */
  36         NULL,                   /* link */
  37         NULL,                   /* unlink */
  38         NULL,                   /* symlink */
  39         NULL,                   /* mkdir */
  40         NULL,                   /* rmdir */
  41         NULL,                   /* mknod */
  42         NULL,                   /* rename */
  43         nfs_readlink,           /* readlink */
  44         nfs_follow_link,        /* follow_link */
  45         NULL,                   /* bmap */
  46         NULL,                   /* truncate */
  47         NULL                    /* permission */
  48 };
  49 
  50 static int nfs_follow_link(struct inode *dir, struct inode *inode,
     /*  */
  51                            int flag, int mode, struct inode **res_inode)
  52 {
  53         int error, *mem;
  54         unsigned int len;
  55         char *res, *res2;
  56 
  57         *res_inode = NULL;
  58         if (!dir) {
  59                 dir = current->fs->root;
  60                 dir->i_count++;
  61         }
  62         if (!inode) {
  63                 iput(dir);
  64                 return -ENOENT;
  65         }
  66         if (!S_ISLNK(inode->i_mode)) {
  67                 iput(dir);
  68                 *res_inode = inode;
  69                 return 0;
  70         }
  71         if (current->link_count > 5) {
  72                 iput(inode);
  73                 iput(dir);
  74                 return -ELOOP;
  75         }
  76         error = nfs_proc_readlink(NFS_SERVER(inode), NFS_FH(inode), &mem,
  77                 &res, &len, NFS_MAXPATHLEN);
  78         if (error) {
  79                 iput(inode);
  80                 iput(dir);
  81                 kfree(mem);
  82                 return error;
  83         }
  84         while ((res2 = (char *) kmalloc(NFS_MAXPATHLEN + 1, GFP_NFS)) == NULL) {
  85                 schedule();
  86         }
  87         memcpy(res2, res, len);
  88         res2[len] = '\0';
  89         kfree(mem);
  90         iput(inode);
  91         current->link_count++;
  92         error = open_namei(res2, flag, mode, res_inode, dir);
  93         current->link_count--;
  94         kfree_s(res2, NFS_MAXPATHLEN + 1);
  95         return error;
  96 }
  97 
  98 static int nfs_readlink(struct inode *inode, char *buffer, int buflen)
     /*  */
  99 {
 100         int error, *mem;
 101         unsigned int len;
 102         char *res;
 103 
 104         if (!S_ISLNK(inode->i_mode)) {
 105                 iput(inode);
 106                 return -EINVAL;
 107         }
 108         if (buflen > NFS_MAXPATHLEN)
 109                 buflen = NFS_MAXPATHLEN;
 110         error = nfs_proc_readlink(NFS_SERVER(inode), NFS_FH(inode), &mem,
 111                 &res, &len, buflen);
 112         iput(inode);
 113         if (! error) {
 114                 memcpy_tofs(buffer, res, len);
 115                 put_fs_byte('\0', buffer + len);
 116                 error = len;
 117         }
 118         kfree(mem);
 119         return error;
 120 }
/* */
root/fs/nfs/symlink.c

DEFINITIONS
