fs/ncpfs/file.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  file.c
   4  *
   5  *  Copyright (C) 1995, 1996 by Volker Lendecke
   6  *  Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
   7  *
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/uaccess.h>
  13
  14 #include <linux/time.h>
  15 #include <linux/kernel.h>
  16 #include <linux/errno.h>
  17 #include <linux/fcntl.h>
  18 #include <linux/stat.h>
  19 #include <linux/mm.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/sched.h>
  22
  23 #include "ncp_fs.h"
  24
  25 static int ncp_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  26 {
  27         return file_write_and_wait_range(file, start, end);
  28 }
  29
  30 /*
  31  * Open a file with the specified read/write mode.
  32  */
  33 int ncp_make_open(struct inode *inode, int right)
  34 {
  35         int error;
  36         int access;
  37
  38         error = -EINVAL;
  39         if (!inode) {
  40                 pr_err("%s: got NULL inode\n", __func__);
  41                 goto out;
  42         }
  43
  44         ncp_dbg(1, "opened=%d, volume # %u, dir entry # %u\n",
  45                 atomic_read(&NCP_FINFO(inode)->opened),
  46                 NCP_FINFO(inode)->volNumber,
  47                 NCP_FINFO(inode)->dirEntNum);
  48         error = -EACCES;
  49         mutex_lock(&NCP_FINFO(inode)->open_mutex);
  50         if (!atomic_read(&NCP_FINFO(inode)->opened)) {
  51                 struct ncp_entry_info finfo;
  52                 int result;
  53
  54                 /* tries max. rights */
  55                 finfo.access = O_RDWR;
  56                 result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
  57                                         inode, NULL, OC_MODE_OPEN,
  58                                         0, AR_READ | AR_WRITE, &finfo);
  59                 if (!result)
  60                         goto update;
  61                 /* RDWR did not succeeded, try readonly or writeonly as requested */
  62                 switch (right) {
  63                         case O_RDONLY:
  64                                 finfo.access = O_RDONLY;
  65                                 result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
  66                                         inode, NULL, OC_MODE_OPEN,
  67                                         0, AR_READ, &finfo);
  68                                 break;
  69                         case O_WRONLY:
  70                                 finfo.access = O_WRONLY;
  71                                 result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
  72                                         inode, NULL, OC_MODE_OPEN,
  73                                         0, AR_WRITE, &finfo);
  74                                 break;
  75                 }
  76                 if (result) {
  77                         ncp_vdbg("failed, result=%d\n", result);
  78                         goto out_unlock;
  79                 }
  80                 /*
  81                  * Update the inode information.
  82                  */
  83         update:
  84                 ncp_update_inode(inode, &finfo);
  85                 atomic_set(&NCP_FINFO(inode)->opened, 1);
  86         }
  87
  88         access = NCP_FINFO(inode)->access;
  89         ncp_vdbg("file open, access=%x\n", access);
  90         if (access == right || access == O_RDWR) {
  91                 atomic_inc(&NCP_FINFO(inode)->opened);
  92                 error = 0;
  93         }
  94
  95 out_unlock:
  96         mutex_unlock(&NCP_FINFO(inode)->open_mutex);
  97 out:
  98         return error;
  99 }
 100
 101 static ssize_t
 102 ncp_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 103 {
 104         struct file *file = iocb->ki_filp;
 105         struct inode *inode = file_inode(file);
 106         size_t already_read = 0;
 107         off_t pos = iocb->ki_pos;
 108         size_t bufsize;
 109         int error;
 110         void *freepage;
 111         size_t freelen;
 112
 113         ncp_dbg(1, "enter %pD2\n", file);
 114
 115         if (!iov_iter_count(to))
 116                 return 0;
 117         if (pos > inode->i_sb->s_maxbytes)
 118                 return 0;
 119         iov_iter_truncate(to, inode->i_sb->s_maxbytes - pos);
 120
 121         error = ncp_make_open(inode, O_RDONLY);
 122         if (error) {
 123                 ncp_dbg(1, "open failed, error=%d\n", error);
 124                 return error;
 125         }
 126
 127         bufsize = NCP_SERVER(inode)->buffer_size;
 128
 129         error = -EIO;
 130         freelen = ncp_read_bounce_size(bufsize);
 131         freepage = vmalloc(freelen);
 132         if (!freepage)
 133                 goto outrel;
 134         error = 0;
 135         /* First read in as much as possible for each bufsize. */
 136         while (iov_iter_count(to)) {
 137                 int read_this_time;
 138                 size_t to_read = min_t(size_t,
 139                                      bufsize - (pos % bufsize),
 140                                      iov_iter_count(to));
 141
 142                 error = ncp_read_bounce(NCP_SERVER(inode),
 143                                 NCP_FINFO(inode)->file_handle,
 144                                 pos, to_read, to, &read_this_time,
 145                                 freepage, freelen);
 146                 if (error) {
 147                         error = -EIO;   /* NW errno -> Linux errno */
 148                         break;
 149                 }
 150                 pos += read_this_time;
 151                 already_read += read_this_time;
 152
 153                 if (read_this_time != to_read)
 154                         break;
 155         }
 156         vfree(freepage);
 157
 158         iocb->ki_pos = pos;
 159
 160         file_accessed(file);
 161
 162         ncp_dbg(1, "exit %pD2\n", file);
 163 outrel:
 164         ncp_inode_close(inode);
 165         return already_read ? already_read : error;
 166 }
 167
 168 static ssize_t
 169 ncp_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 170 {
 171         struct file *file = iocb->ki_filp;
 172         struct inode *inode = file_inode(file);
 173         size_t already_written = 0;
 174         size_t bufsize;
 175         int errno;
 176         void *bouncebuffer;
 177         off_t pos;
 178
 179         ncp_dbg(1, "enter %pD2\n", file);
 180         errno = generic_write_checks(iocb, from);
 181         if (errno <= 0)
 182                 return errno;
 183
 184         errno = ncp_make_open(inode, O_WRONLY);
 185         if (errno) {
 186                 ncp_dbg(1, "open failed, error=%d\n", errno);
 187                 return errno;
 188         }
 189         bufsize = NCP_SERVER(inode)->buffer_size;
 190
 191         errno = file_update_time(file);
 192         if (errno)
 193                 goto outrel;
 194
 195         bouncebuffer = vmalloc(bufsize);
 196         if (!bouncebuffer) {
 197                 errno = -EIO;   /* -ENOMEM */
 198                 goto outrel;
 199         }
 200         pos = iocb->ki_pos;
 201         while (iov_iter_count(from)) {
 202                 int written_this_time;
 203                 size_t to_write = min_t(size_t,
 204                                       bufsize - (pos % bufsize),
 205                                       iov_iter_count(from));
 206
 207                 if (!copy_from_iter_full(bouncebuffer, to_write, from)) {
 208                         errno = -EFAULT;
 209                         break;
 210                 }
 211                 if (ncp_write_kernel(NCP_SERVER(inode),
 212                     NCP_FINFO(inode)->file_handle,
 213                     pos, to_write, bouncebuffer, &written_this_time) != 0) {
 214                         errno = -EIO;
 215                         break;
 216                 }
 217                 pos += written_this_time;
 218                 already_written += written_this_time;
 219
 220                 if (written_this_time != to_write)
 221                         break;
 222         }
 223         vfree(bouncebuffer);
 224
 225         iocb->ki_pos = pos;
 226
 227         if (pos > i_size_read(inode)) {
 228                 inode_lock(inode);
 229                 if (pos > i_size_read(inode))
 230                         i_size_write(inode, pos);
 231                 inode_unlock(inode);
 232         }
 233         ncp_dbg(1, "exit %pD2\n", file);
 234 outrel:
 235         ncp_inode_close(inode);
 236         return already_written ? already_written : errno;
 237 }
 238
 239 static int ncp_release(struct inode *inode, struct file *file) {
 240         if (ncp_make_closed(inode)) {
 241                 ncp_dbg(1, "failed to close\n");
 242         }
 243         return 0;
 244 }
 245
 246 const struct file_operations ncp_file_operations =
 247 {
 248         .llseek         = generic_file_llseek,
 249         .read_iter      = ncp_file_read_iter,
 250         .write_iter     = ncp_file_write_iter,
 251         .unlocked_ioctl = ncp_ioctl,
 252 #ifdef CONFIG_COMPAT
 253         .compat_ioctl   = ncp_compat_ioctl,
 254 #endif
 255         .mmap           = ncp_mmap,
 256         .release        = ncp_release,
 257         .fsync          = ncp_fsync,
 258 };
 259
 260 const struct inode_operations ncp_file_inode_operations =
 261 {
 262         .setattr        = ncp_notify_change,
 263 };