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
  36 #include "debug.h"
  37 #include "v9fs.h"
  38 #include "9p.h"
  39 #include "conv.h"
  40 #include "v9fs_vfs.h"
  41 #include "fid.h"
  42
  43 /**
  44  * dt_type - return file type
  45  * @mistat: mistat structure
  46  *
  47  */
  48
  49 static inline int dt_type(struct v9fs_stat *mistat)
  50 {
  51         unsigned long perm = mistat->mode;
  52         int rettype = DT_REG;
  53
  54         if (perm & V9FS_DMDIR)
  55                 rettype = DT_DIR;
  56         if (perm & V9FS_DMSYMLINK)
  57                 rettype = DT_LNK;
  58
  59         return rettype;
  60 }
  61
  62 /**
  63  * v9fs_dir_readdir - read a directory
  64  * @filep: opened file structure
  65  * @dirent: directory structure ???
  66  * @filldir: function to populate directory structure ???
  67  *
  68  */
  69
  70 static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
  71 {
  72         struct v9fs_fcall *fcall = NULL;
  73         struct inode *inode = filp->f_path.dentry->d_inode;
  74         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
  75         struct v9fs_fid *file = filp->private_data;
  76         unsigned int i, n, s;
  77         int fid = -1;
  78         int ret = 0;
  79         struct v9fs_stat stat;
  80         int over = 0;
  81
  82         dprintk(DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
  83
  84         fid = file->fid;
  85
  86         if (file->rdir_fcall && (filp->f_pos != file->rdir_pos)) {
  87                 kfree(file->rdir_fcall);
  88                 file->rdir_fcall = NULL;
  89         }
  90
  91         if (file->rdir_fcall) {
  92                 n = file->rdir_fcall->params.rread.count;
  93                 i = file->rdir_fpos;
  94                 while (i < n) {
  95                         s = v9fs_deserialize_stat(
  96                                 file->rdir_fcall->params.rread.data + i,
  97                                 n - i, &stat, v9ses->extended);
  98
  99                         if (s == 0) {
 100                                 dprintk(DEBUG_ERROR,
 101                                         "error while deserializing stat\n");
 102                                 ret = -EIO;
 103                                 goto FreeStructs;
 104                         }
 105
 106                         over = filldir(dirent, stat.name.str, stat.name.len,
 107                                     filp->f_pos, v9fs_qid2ino(&stat.qid),
 108                                     dt_type(&stat));
 109
 110                         if (over) {
 111                                 file->rdir_fpos = i;
 112                                 file->rdir_pos = filp->f_pos;
 113                                 break;
 114                         }
 115
 116                         i += s;
 117                         filp->f_pos += s;
 118                 }
 119
 120                 if (!over) {
 121                         kfree(file->rdir_fcall);
 122                         file->rdir_fcall = NULL;
 123                 }
 124         }
 125
 126         while (!over) {
 127                 ret = v9fs_t_read(v9ses, fid, filp->f_pos,
 128                         v9ses->maxdata-V9FS_IOHDRSZ, &fcall);
 129                 if (ret < 0) {
 130                         dprintk(DEBUG_ERROR, "error while reading: %d: %p\n",
 131                                 ret, fcall);
 132                         goto FreeStructs;
 133                 } else if (ret == 0)
 134                         break;
 135
 136                 n = ret;
 137                 i = 0;
 138                 while (i < n) {
 139                         s = v9fs_deserialize_stat(fcall->params.rread.data + i,
 140                                 n - i, &stat, v9ses->extended);
 141
 142                         if (s == 0) {
 143                                 dprintk(DEBUG_ERROR,
 144                                         "error while deserializing stat\n");
 145                                 return -EIO;
 146                         }
 147
 148                         over = filldir(dirent, stat.name.str, stat.name.len,
 149                                     filp->f_pos, v9fs_qid2ino(&stat.qid),
 150                                     dt_type(&stat));
 151
 152                         if (over) {
 153                                 file->rdir_fcall = fcall;
 154                                 file->rdir_fpos = i;
 155                                 file->rdir_pos = filp->f_pos;
 156                                 fcall = NULL;
 157                                 break;
 158                         }
 159
 160                         i += s;
 161                         filp->f_pos += s;
 162                 }
 163
 164                 kfree(fcall);
 165         }
 166
 167       FreeStructs:
 168         kfree(fcall);
 169         return ret;
 170 }
 171
 172 /**
 173  * v9fs_dir_release - close a directory
 174  * @inode: inode of the directory
 175  * @filp: file pointer to a directory
 176  *
 177  */
 178
 179 int v9fs_dir_release(struct inode *inode, struct file *filp)
 180 {
 181         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 182         struct v9fs_fid *fid = filp->private_data;
 183         int fidnum = -1;
 184
 185         dprintk(DEBUG_VFS, "inode: %p filp: %p fid: %d\n", inode, filp,
 186                 fid->fid);
 187         fidnum = fid->fid;
 188
 189         filemap_write_and_wait(inode->i_mapping);
 190
 191         if (fidnum >= 0) {
 192                 dprintk(DEBUG_VFS, "fidopen: %d v9f->fid: %d\n", fid->fidopen,
 193                         fid->fid);
 194
 195                 if (v9fs_t_clunk(v9ses, fidnum))
 196                         dprintk(DEBUG_ERROR, "clunk failed\n");
 197
 198                 kfree(fid->rdir_fcall);
 199                 kfree(fid);
 200
 201                 filp->private_data = NULL;
 202         }
 203
 204         return 0;
 205 }
 206
 207 const struct file_operations v9fs_dir_operations = {
 208         .read = generic_read_dir,
 209         .readdir = v9fs_dir_readdir,
 210         .open = v9fs_file_open,
 211         .release = v9fs_dir_release,
 212 };