fs/ncpfs/file.c

   1 /*
   2  *  file.c
   3  *
   4  *  Copyright (C) 1995, 1996 by Volker Lendecke
   5  *  Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
   6  *
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11 #include <linux/uaccess.h>
  12
  13 #include <linux/time.h>
  14 #include <linux/kernel.h>
  15 #include <linux/errno.h>
  16 #include <linux/fcntl.h>
  17 #include <linux/stat.h>
  18 #include <linux/mm.h>
  19 #include <linux/vmalloc.h>
  20 #include <linux/sched.h>
  21
  22 #include "ncp_fs.h"
  23
  24 static int ncp_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  25 {
  26         return filemap_write_and_wait_range(file->f_mapping, start, end);
  27 }
  28
  29 /*
  30  * Open a file with the specified read/write mode.
  31  */
  32 int ncp_make_open(struct inode *inode, int right)
  33 {
  34         int error;
  35         int access;
  36
  37         error = -EINVAL;
  38         if (!inode) {
  39                 pr_err("%s: got NULL inode\n", __func__);
  40                 goto out;
  41         }
  42
  43         ncp_dbg(1, "opened=%d, volume # %u, dir entry # %u\n",
  44                 atomic_read(&NCP_FINFO(inode)->opened),
  45                 NCP_FINFO(inode)->volNumber,
  46                 NCP_FINFO(inode)->dirEntNum);
  47         error = -EACCES;
  48         mutex_lock(&NCP_FINFO(inode)->open_mutex);
  49         if (!atomic_read(&NCP_FINFO(inode)->opened)) {
  50                 struct ncp_entry_info finfo;
  51                 int result;
  52
  53                 /* tries max. rights */
  54                 finfo.access = O_RDWR;
  55                 result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
  56                                         inode, NULL, OC_MODE_OPEN,
  57                                         0, AR_READ | AR_WRITE, &finfo);
  58                 if (!result)
  59                         goto update;
  60                 /* RDWR did not succeeded, try readonly or writeonly as requested */
  61                 switch (right) {
  62                         case O_RDONLY:
  63                                 finfo.access = O_RDONLY;
  64                                 result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
  65                                         inode, NULL, OC_MODE_OPEN,
  66                                         0, AR_READ, &finfo);
  67                                 break;
  68                         case O_WRONLY:
  69                                 finfo.access = O_WRONLY;
  70                                 result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
  71                                         inode, NULL, OC_MODE_OPEN,
  72                                         0, AR_WRITE, &finfo);
  73                                 break;
  74                 }
  75                 if (result) {
  76                         ncp_vdbg("failed, result=%d\n", result);
  77                         goto out_unlock;
  78                 }
  79                 /*
  80                  * Update the inode information.
  81                  */
  82         update:
  83                 ncp_update_inode(inode, &finfo);
  84                 atomic_set(&NCP_FINFO(inode)->opened, 1);
  85         }
  86
  87         access = NCP_FINFO(inode)->access;
  88         ncp_vdbg("file open, access=%x\n", access);
  89         if (access == right || access == O_RDWR) {
  90                 atomic_inc(&NCP_FINFO(inode)->opened);
  91                 error = 0;
  92         }
  93
  94 out_unlock:
  95         mutex_unlock(&NCP_FINFO(inode)->open_mutex);
  96 out:
  97         return error;
  98 }
  99
 100 static ssize_t
 101 ncp_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 102 {
 103         struct file *file = iocb->ki_filp;
 104         struct inode *inode = file_inode(file);
 105         size_t already_read = 0;
 106         off_t pos = iocb->ki_pos;
 107         size_t bufsize;
 108         int error;
 109         void *freepage;
 110         size_t freelen;
 111
 112         ncp_dbg(1, "enter %pD2\n", file);
 113
 114         if (!iov_iter_count(to))
 115                 return 0;
 116         if (pos > inode->i_sb->s_maxbytes)
 117                 return 0;
 118         iov_iter_truncate(to, inode->i_sb->s_maxbytes - pos);
 119
 120         error = ncp_make_open(inode, O_RDONLY);
 121         if (error) {
 122                 ncp_dbg(1, "open failed, error=%d\n", error);
 123                 return error;
 124         }
 125
 126         bufsize = NCP_SERVER(inode)->buffer_size;
 127
 128         error = -EIO;
 129         freelen = ncp_read_bounce_size(bufsize);
 130         freepage = vmalloc(freelen);
 131         if (!freepage)
 132                 goto outrel;
 133         error = 0;
 134         /* First read in as much as possible for each bufsize. */
 135         while (iov_iter_count(to)) {
 136                 int read_this_time;
 137                 size_t to_read = min_t(size_t,
 138                                      bufsize - (pos % bufsize),
 139                                      iov_iter_count(to));
 140
 141                 error = ncp_read_bounce(NCP_SERVER(inode),
 142                                 NCP_FINFO(inode)->file_handle,
 143                                 pos, to_read, to, &read_this_time,
 144                                 freepage, freelen);
 145                 if (error) {
 146                         error = -EIO;   /* NW errno -> Linux errno */
 147                         break;
 148                 }
 149                 pos += read_this_time;
 150                 already_read += read_this_time;
 151
 152                 if (read_this_time != to_read)
 153                         break;
 154         }
 155         vfree(freepage);
 156
 157         iocb->ki_pos = pos;
 158
 159         file_accessed(file);
 160
 161         ncp_dbg(1, "exit %pD2\n", file);
 162 outrel:
 163         ncp_inode_close(inode);
 164         return already_read ? already_read : error;
 165 }
 166
 167 static ssize_t
 168 ncp_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 169 {
 170         struct file *file = iocb->ki_filp;
 171         struct inode *inode = file_inode(file);
 172         size_t already_written = 0;
 173         size_t bufsize;
 174         int errno;
 175         void *bouncebuffer;
 176         off_t pos;
 177
 178         ncp_dbg(1, "enter %pD2\n", file);
 179         errno = generic_write_checks(iocb, from);
 180         if (errno <= 0)
 181                 return errno;
 182
 183         errno = ncp_make_open(inode, O_WRONLY);
 184         if (errno) {
 185                 ncp_dbg(1, "open failed, error=%d\n", errno);
 186                 return errno;
 187         }
 188         bufsize = NCP_SERVER(inode)->buffer_size;
 189
 190         errno = file_update_time(file);
 191         if (errno)
 192                 goto outrel;
 193
 194         bouncebuffer = vmalloc(bufsize);
 195         if (!bouncebuffer) {
 196                 errno = -EIO;   /* -ENOMEM */
 197                 goto outrel;
 198         }
 199         pos = iocb->ki_pos;
 200         while (iov_iter_count(from)) {
 201                 int written_this_time;
 202                 size_t to_write = min_t(size_t,
 203                                       bufsize - (pos % bufsize),
 204                                       iov_iter_count(from));
 205
 206                 if (!copy_from_iter_full(bouncebuffer, to_write, from)) {
 207                         errno = -EFAULT;
 208                         break;
 209                 }
 210                 if (ncp_write_kernel(NCP_SERVER(inode),
 211                     NCP_FINFO(inode)->file_handle,
 212                     pos, to_write, bouncebuffer, &written_this_time) != 0) {
 213                         errno = -EIO;
 214                         break;
 215                 }
 216                 pos += written_this_time;
 217                 already_written += written_this_time;
 218
 219                 if (written_this_time != to_write)
 220                         break;
 221         }
 222         vfree(bouncebuffer);
 223
 224         iocb->ki_pos = pos;
 225
 226         if (pos > i_size_read(inode)) {
 227                 inode_lock(inode);
 228                 if (pos > i_size_read(inode))
 229                         i_size_write(inode, pos);
 230                 inode_unlock(inode);
 231         }
 232         ncp_dbg(1, "exit %pD2\n", file);
 233 outrel:
 234         ncp_inode_close(inode);
 235         return already_written ? already_written : errno;
 236 }
 237
 238 static int ncp_release(struct inode *inode, struct file *file) {
 239         if (ncp_make_closed(inode)) {
 240                 ncp_dbg(1, "failed to close\n");
 241         }
 242         return 0;
 243 }
 244
 245 const struct file_operations ncp_file_operations =
 246 {
 247         .llseek         = generic_file_llseek,
 248         .read_iter      = ncp_file_read_iter,
 249         .write_iter     = ncp_file_write_iter,
 250         .unlocked_ioctl = ncp_ioctl,
 251 #ifdef CONFIG_COMPAT
 252         .compat_ioctl   = ncp_compat_ioctl,
 253 #endif
 254         .mmap           = ncp_mmap,
 255         .release        = ncp_release,
 256         .fsync          = ncp_fsync,
 257 };
 258
 259 const struct inode_operations ncp_file_inode_operations =
 260 {
 261         .setattr        = ncp_notify_change,
 262 };