fs/9p/vfs_dir.c

   1 /*
   2  * linux/fs/9p/vfs_dir.c
   3  *
   4  * This file contains vfs directory ops for the 9P2000 protocol.
   5  *
   6  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/fs.h>
  29 #include <linux/file.h>
  30 #include <linux/stat.h>
  31 #include <linux/string.h>
  32 #include <linux/sched.h>
  33 #include <linux/inet.h>
  34 #include <linux/idr.h>
  35 #include <net/9p/9p.h>
  36 #include <net/9p/client.h>
  37
  38 #include "v9fs.h"
  39 #include "v9fs_vfs.h"
  40 #include "fid.h"
  41
  42 /**
  43  * dt_type - return file type
  44  * @mistat: mistat structure
  45  *
  46  */
  47
  48 static inline int dt_type(struct p9_stat *mistat)
  49 {
  50         unsigned long perm = mistat->mode;
  51         int rettype = DT_REG;
  52
  53         if (perm & P9_DMDIR)
  54                 rettype = DT_DIR;
  55         if (perm & P9_DMSYMLINK)
  56                 rettype = DT_LNK;
  57
  58         return rettype;
  59 }
  60
  61 /**
  62  * v9fs_dir_readdir - read a directory
  63  * @filp: opened file structure
  64  * @dirent: directory structure ???
  65  * @filldir: function to populate directory structure ???
  66  *
  67  */
  68
  69 static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
  70 {
  71         int over;
  72         struct p9_stat st;
  73         int err;
  74         struct p9_fid *fid;
  75         int buflen;
  76         char *statbuf;
  77         int n, i = 0;
  78
  79         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
  80         fid = filp->private_data;
  81
  82         buflen = fid->clnt->msize - P9_IOHDRSZ;
  83         statbuf = kmalloc(buflen, GFP_KERNEL);
  84         if (!statbuf)
  85                 return -ENOMEM;
  86
  87         while (1) {
  88                 err = v9fs_file_readn(filp, statbuf, NULL, buflen,
  89                                                                 fid->rdir_fpos);
  90                 if (err <= 0)
  91                         break;
  92
  93                 n = err;
  94                 while (i < n) {
  95                         err = p9_deserialize_stat(statbuf + i, buflen-i, &st,
  96                                                         fid->clnt->dotu);
  97                         if (!err) {
  98                                 err = -EIO;
  99                                 goto free_and_exit;
 100                         }
 101
 102                         i += err;
 103                         fid->rdir_fpos += err;
 104
 105                         over = filldir(dirent, st.name.str, st.name.len,
 106                             filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
 107
 108                         filp->f_pos += st.size;
 109
 110                         if (over) {
 111                                 err = 0;
 112                                 goto free_and_exit;
 113                         }
 114                 }
 115         }
 116
 117 free_and_exit:
 118         kfree(statbuf);
 119         return err;
 120 }
 121
 122
 123 /**
 124  * v9fs_dir_release - close a directory
 125  * @inode: inode of the directory
 126  * @filp: file pointer to a directory
 127  *
 128  */
 129
 130 int v9fs_dir_release(struct inode *inode, struct file *filp)
 131 {
 132         struct p9_fid *fid;
 133
 134         fid = filp->private_data;
 135         P9_DPRINTK(P9_DEBUG_VFS,
 136                         "inode: %p filp: %p fid: %d\n", inode, filp, fid->fid);
 137         filemap_write_and_wait(inode->i_mapping);
 138         p9_client_clunk(fid);
 139         return 0;
 140 }
 141
 142 const struct file_operations v9fs_dir_operations = {
 143         .read = generic_read_dir,
 144         .llseek = generic_file_llseek,
 145         .readdir = v9fs_dir_readdir,
 146         .open = v9fs_file_open,
 147         .release = v9fs_dir_release,
 148 };