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 <asm/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(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 102 {
 103         struct dentry *dentry = file->f_path.dentry;
 104         struct inode *inode = dentry->d_inode;
 105         size_t already_read = 0;
 106         off_t pos;
 107         size_t bufsize;
 108         int error;
 109         void* freepage;
 110         size_t freelen;
 111
 112         ncp_dbg(1, "enter %pd2\n", dentry);
 113
 114         pos = *ppos;
 115
 116         if ((ssize_t) count < 0) {
 117                 return -EINVAL;
 118         }
 119         if (!count)
 120                 return 0;
 121         if (pos > inode->i_sb->s_maxbytes)
 122                 return 0;
 123         if (pos + count > inode->i_sb->s_maxbytes) {
 124                 count = inode->i_sb->s_maxbytes - pos;
 125         }
 126
 127         error = ncp_make_open(inode, O_RDONLY);
 128         if (error) {
 129                 ncp_dbg(1, "open failed, error=%d\n", error);
 130                 return error;
 131         }
 132
 133         bufsize = NCP_SERVER(inode)->buffer_size;
 134
 135         error = -EIO;
 136         freelen = ncp_read_bounce_size(bufsize);
 137         freepage = vmalloc(freelen);
 138         if (!freepage)
 139                 goto outrel;
 140         error = 0;
 141         /* First read in as much as possible for each bufsize. */
 142         while (already_read < count) {
 143                 int read_this_time;
 144                 size_t to_read = min_t(unsigned int,
 145                                      bufsize - (pos % bufsize),
 146                                      count - already_read);
 147
 148                 error = ncp_read_bounce(NCP_SERVER(inode),
 149                                 NCP_FINFO(inode)->file_handle,
 150                                 pos, to_read, buf, &read_this_time,
 151                                 freepage, freelen);
 152                 if (error) {
 153                         error = -EIO;   /* NW errno -> Linux errno */
 154                         break;
 155                 }
 156                 pos += read_this_time;
 157                 buf += read_this_time;
 158                 already_read += read_this_time;
 159
 160                 if (read_this_time != to_read) {
 161                         break;
 162                 }
 163         }
 164         vfree(freepage);
 165
 166         *ppos = pos;
 167
 168         file_accessed(file);
 169
 170         ncp_dbg(1, "exit %pd2\n", dentry);
 171 outrel:
 172         ncp_inode_close(inode);
 173         return already_read ? already_read : error;
 174 }
 175
 176 static ssize_t
 177 ncp_file_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
 178 {
 179         struct dentry *dentry = file->f_path.dentry;
 180         struct inode *inode = dentry->d_inode;
 181         size_t already_written = 0;
 182         off_t pos;
 183         size_t bufsize;
 184         int errno;
 185         void* bouncebuffer;
 186
 187         ncp_dbg(1, "enter %pd2\n", dentry);
 188         if ((ssize_t) count < 0)
 189                 return -EINVAL;
 190         pos = *ppos;
 191         if (file->f_flags & O_APPEND) {
 192                 pos = i_size_read(inode);
 193         }
 194
 195         if (pos + count > MAX_NON_LFS && !(file->f_flags&O_LARGEFILE)) {
 196                 if (pos >= MAX_NON_LFS) {
 197                         return -EFBIG;
 198                 }
 199                 if (count > MAX_NON_LFS - (u32)pos) {
 200                         count = MAX_NON_LFS - (u32)pos;
 201                 }
 202         }
 203         if (pos >= inode->i_sb->s_maxbytes) {
 204                 if (count || pos > inode->i_sb->s_maxbytes) {
 205                         return -EFBIG;
 206                 }
 207         }
 208         if (pos + count > inode->i_sb->s_maxbytes) {
 209                 count = inode->i_sb->s_maxbytes - pos;
 210         }
 211
 212         if (!count)
 213                 return 0;
 214         errno = ncp_make_open(inode, O_WRONLY);
 215         if (errno) {
 216                 ncp_dbg(1, "open failed, error=%d\n", errno);
 217                 return errno;
 218         }
 219         bufsize = NCP_SERVER(inode)->buffer_size;
 220
 221         already_written = 0;
 222
 223         errno = file_update_time(file);
 224         if (errno)
 225                 goto outrel;
 226
 227         bouncebuffer = vmalloc(bufsize);
 228         if (!bouncebuffer) {
 229                 errno = -EIO;   /* -ENOMEM */
 230                 goto outrel;
 231         }
 232         while (already_written < count) {
 233                 int written_this_time;
 234                 size_t to_write = min_t(unsigned int,
 235                                       bufsize - (pos % bufsize),
 236                                       count - already_written);
 237
 238                 if (copy_from_user(bouncebuffer, buf, to_write)) {
 239                         errno = -EFAULT;
 240                         break;
 241                 }
 242                 if (ncp_write_kernel(NCP_SERVER(inode),
 243                     NCP_FINFO(inode)->file_handle,
 244                     pos, to_write, bouncebuffer, &written_this_time) != 0) {
 245                         errno = -EIO;
 246                         break;
 247                 }
 248                 pos += written_this_time;
 249                 buf += written_this_time;
 250                 already_written += written_this_time;
 251
 252                 if (written_this_time != to_write) {
 253                         break;
 254                 }
 255         }
 256         vfree(bouncebuffer);
 257
 258         *ppos = pos;
 259
 260         if (pos > i_size_read(inode)) {
 261                 mutex_lock(&inode->i_mutex);
 262                 if (pos > i_size_read(inode))
 263                         i_size_write(inode, pos);
 264                 mutex_unlock(&inode->i_mutex);
 265         }
 266         ncp_dbg(1, "exit %pd2\n", dentry);
 267 outrel:
 268         ncp_inode_close(inode);
 269         return already_written ? already_written : errno;
 270 }
 271
 272 static int ncp_release(struct inode *inode, struct file *file) {
 273         if (ncp_make_closed(inode)) {
 274                 ncp_dbg(1, "failed to close\n");
 275         }
 276         return 0;
 277 }
 278
 279 const struct file_operations ncp_file_operations =
 280 {
 281         .llseek         = generic_file_llseek,
 282         .read           = ncp_file_read,
 283         .write          = ncp_file_write,
 284         .unlocked_ioctl = ncp_ioctl,
 285 #ifdef CONFIG_COMPAT
 286         .compat_ioctl   = ncp_compat_ioctl,
 287 #endif
 288         .mmap           = ncp_mmap,
 289         .release        = ncp_release,
 290         .fsync          = ncp_fsync,
 291 };
 292
 293 const struct inode_operations ncp_file_inode_operations =
 294 {
 295         .setattr        = ncp_notify_change,
 296 };