fs/cifs/ioctl.c

   1 /*
   2  *   fs/cifs/ioctl.c
   3  *
   4  *   vfs operations that deal with io control
   5  *
   6  *   Copyright (C) International Business Machines  Corp., 2005,2013
   7  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *
   9  *   This library is free software; you can redistribute it and/or modify
  10  *   it under the terms of the GNU Lesser General Public License as published
  11  *   by the Free Software Foundation; either version 2.1 of the License, or
  12  *   (at your option) any later version.
  13  *
  14  *   This library is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  *   the GNU Lesser General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU Lesser General Public License
  20  *   along with this library; if not, write to the Free Software
  21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 #include <linux/fs.h>
  25 #include <linux/file.h>
  26 #include <linux/mount.h>
  27 #include <linux/mm.h>
  28 #include <linux/pagemap.h>
  29 #include "cifspdu.h"
  30 #include "cifsglob.h"
  31 #include "cifsproto.h"
  32 #include "cifs_debug.h"
  33 #include "cifsfs.h"
  34
  35 #define CIFS_IOCTL_MAGIC        0xCF
  36 #define CIFS_IOC_COPYCHUNK_FILE _IOW(CIFS_IOCTL_MAGIC, 3, int)
  37
  38 static long cifs_ioctl_clone(unsigned int xid, struct file *dst_file,
  39                         unsigned long srcfd, u64 off, u64 len, u64 destoff)
  40 {
  41         int rc;
  42         struct cifsFileInfo *smb_file_target = dst_file->private_data;
  43         struct inode *target_inode = file_inode(dst_file);
  44         struct cifs_tcon *target_tcon;
  45         struct fd src_file;
  46         struct cifsFileInfo *smb_file_src;
  47         struct inode *src_inode;
  48         struct cifs_tcon *src_tcon;
  49
  50         cifs_dbg(FYI, "ioctl clone range\n");
  51         /* the destination must be opened for writing */
  52         if (!(dst_file->f_mode & FMODE_WRITE)) {
  53                 cifs_dbg(FYI, "file target not open for write\n");
  54                 return -EINVAL;
  55         }
  56
  57         /* check if target volume is readonly and take reference */
  58         rc = mnt_want_write_file(dst_file);
  59         if (rc) {
  60                 cifs_dbg(FYI, "mnt_want_write failed with rc %d\n", rc);
  61                 return rc;
  62         }
  63
  64         src_file = fdget(srcfd);
  65         if (!src_file.file) {
  66                 rc = -EBADF;
  67                 goto out_drop_write;
  68         }
  69
  70         if ((!src_file.file->private_data) || (!dst_file->private_data)) {
  71                 rc = -EBADF;
  72                 cifs_dbg(VFS, "missing cifsFileInfo on copy range src file\n");
  73                 goto out_fput;
  74         }
  75
  76         rc = -EXDEV;
  77         smb_file_target = dst_file->private_data;
  78         smb_file_src = src_file.file->private_data;
  79         src_tcon = tlink_tcon(smb_file_src->tlink);
  80         target_tcon = tlink_tcon(smb_file_target->tlink);
  81
  82         /* check if source and target are on same tree connection */
  83         if (src_tcon != target_tcon) {
  84                 cifs_dbg(VFS, "file copy src and target on different volume\n");
  85                 goto out_fput;
  86         }
  87
  88         src_inode = file_inode(src_file.file);
  89
  90         /*
  91          * Note: cifs case is easier than btrfs since server responsible for
  92          * checks for proper open modes and file type and if it wants
  93          * server could even support copy of range where source = target
  94          */
  95
  96         /* so we do not deadlock racing two ioctls on same files */
  97         if (target_inode < src_inode) {
  98                 mutex_lock_nested(&target_inode->i_mutex, I_MUTEX_PARENT);
  99                 mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_CHILD);
 100         } else {
 101                 mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_PARENT);
 102                 mutex_lock_nested(&target_inode->i_mutex, I_MUTEX_CHILD);
 103         }
 104
 105         /* determine range to clone */
 106         rc = -EINVAL;
 107         if (off + len > src_inode->i_size || off + len < off)
 108                 goto out_unlock;
 109         if (len == 0)
 110                 len = src_inode->i_size - off;
 111
 112         cifs_dbg(FYI, "about to flush pages\n");
 113         /* should we flush first and last page first */
 114         truncate_inode_pages_range(&target_inode->i_data, destoff,
 115                                    PAGE_CACHE_ALIGN(destoff + len)-1);
 116
 117         if (target_tcon->ses->server->ops->clone_range)
 118                 rc = target_tcon->ses->server->ops->clone_range(xid,
 119                         smb_file_src, smb_file_target, off, len, destoff);
 120
 121         /* force revalidate of size and timestamps of target file now
 122            that target is updated on the server */
 123         CIFS_I(target_inode)->time = 0;
 124 out_unlock:
 125         /* although unlocking in the reverse order from locking is not
 126            strictly necessary here it is a little cleaner to be consistent */
 127         if (target_inode < src_inode) {
 128                 mutex_unlock(&src_inode->i_mutex);
 129                 mutex_unlock(&target_inode->i_mutex);
 130         } else {
 131                 mutex_unlock(&target_inode->i_mutex);
 132                 mutex_unlock(&src_inode->i_mutex);
 133         }
 134 out_fput:
 135         fdput(src_file);
 136 out_drop_write:
 137         mnt_drop_write_file(dst_file);
 138         return rc;
 139 }
 140
 141 long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
 142 {
 143         struct inode *inode = file_inode(filep);
 144         int rc = -ENOTTY; /* strange error - but the precedent */
 145         unsigned int xid;
 146         struct cifs_sb_info *cifs_sb;
 147         struct cifsFileInfo *pSMBFile = filep->private_data;
 148         struct cifs_tcon *tcon;
 149         __u64   ExtAttrBits = 0;
 150         __u64   caps;
 151
 152         xid = get_xid();
 153
 154         cifs_dbg(FYI, "ioctl file %p  cmd %u  arg %lu\n", filep, command, arg);
 155
 156         cifs_sb = CIFS_SB(inode->i_sb);
 157
 158         switch (command) {
 159                 case FS_IOC_GETFLAGS:
 160                         if (pSMBFile == NULL)
 161                                 break;
 162                         tcon = tlink_tcon(pSMBFile->tlink);
 163                         caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
 164 #ifdef CONFIG_CIFS_POSIX
 165                         if (CIFS_UNIX_EXTATTR_CAP & caps) {
 166                                 __u64   ExtAttrMask = 0;
 167                                 rc = CIFSGetExtAttr(xid, tcon,
 168                                                     pSMBFile->fid.netfid,
 169                                                     &ExtAttrBits, &ExtAttrMask);
 170                                 if (rc == 0)
 171                                         rc = put_user(ExtAttrBits &
 172                                                 FS_FL_USER_VISIBLE,
 173                                                 (int __user *)arg);
 174                                 if (rc != EOPNOTSUPP)
 175                                         break;
 176                         }
 177 #endif /* CONFIG_CIFS_POSIX */
 178                         rc = 0;
 179                         if (CIFS_I(inode)->cifsAttrs & ATTR_COMPRESSED) {
 180                                 /* add in the compressed bit */
 181                                 ExtAttrBits = FS_COMPR_FL;
 182                                 rc = put_user(ExtAttrBits & FS_FL_USER_VISIBLE,
 183                                               (int __user *)arg);
 184                         }
 185                         break;
 186                 case FS_IOC_SETFLAGS:
 187                         if (pSMBFile == NULL)
 188                                 break;
 189                         tcon = tlink_tcon(pSMBFile->tlink);
 190                         caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
 191
 192                         if (get_user(ExtAttrBits, (int __user *)arg)) {
 193                                 rc = -EFAULT;
 194                                 break;
 195                         }
 196
 197                         /*
 198                          * if (CIFS_UNIX_EXTATTR_CAP & caps)
 199                          *      rc = CIFSSetExtAttr(xid, tcon,
 200                          *                     pSMBFile->fid.netfid,
 201                          *                     extAttrBits,
 202                          *                     &ExtAttrMask);
 203                          * if (rc != EOPNOTSUPP)
 204                          *      break;
 205                          */
 206
 207                         /* Currently only flag we can set is compressed flag */
 208                         if ((ExtAttrBits & FS_COMPR_FL) == 0)
 209                                 break;
 210
 211                         /* Try to set compress flag */
 212                         if (tcon->ses->server->ops->set_compression) {
 213                                 rc = tcon->ses->server->ops->set_compression(
 214                                                         xid, tcon, pSMBFile);
 215                                 cifs_dbg(FYI, "set compress flag rc %d\n", rc);
 216                         }
 217                         break;
 218                 case CIFS_IOC_COPYCHUNK_FILE:
 219                         rc = cifs_ioctl_clone(xid, filep, arg, 0, 0, 0);
 220                         break;
 221                 default:
 222                         cifs_dbg(FYI, "unsupported ioctl\n");
 223                         break;
 224         }
 225
 226         free_xid(xid);
 227         return rc;
 228 }