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 #include <linux/btrfs.h>
  35
  36 #define CIFS_IOCTL_MAGIC        0xCF
  37 #define CIFS_IOC_COPYCHUNK_FILE _IOW(CIFS_IOCTL_MAGIC, 3, int)
  38
  39 static long cifs_ioctl_clone(unsigned int xid, struct file *dst_file,
  40                         unsigned long srcfd, u64 off, u64 len, u64 destoff,
  41                         bool dup_extents)
  42 {
  43         int rc;
  44         struct cifsFileInfo *smb_file_target = dst_file->private_data;
  45         struct inode *target_inode = file_inode(dst_file);
  46         struct cifs_tcon *target_tcon;
  47         struct fd src_file;
  48         struct cifsFileInfo *smb_file_src;
  49         struct inode *src_inode;
  50         struct cifs_tcon *src_tcon;
  51
  52         cifs_dbg(FYI, "ioctl clone range\n");
  53         /* the destination must be opened for writing */
  54         if (!(dst_file->f_mode & FMODE_WRITE)) {
  55                 cifs_dbg(FYI, "file target not open for write\n");
  56                 return -EINVAL;
  57         }
  58
  59         /* check if target volume is readonly and take reference */
  60         rc = mnt_want_write_file(dst_file);
  61         if (rc) {
  62                 cifs_dbg(FYI, "mnt_want_write failed with rc %d\n", rc);
  63                 return rc;
  64         }
  65
  66         src_file = fdget(srcfd);
  67         if (!src_file.file) {
  68                 rc = -EBADF;
  69                 goto out_drop_write;
  70         }
  71
  72         if ((!src_file.file->private_data) || (!dst_file->private_data)) {
  73                 rc = -EBADF;
  74                 cifs_dbg(VFS, "missing cifsFileInfo on copy range src file\n");
  75                 goto out_fput;
  76         }
  77
  78         rc = -EXDEV;
  79         smb_file_target = dst_file->private_data;
  80         smb_file_src = src_file.file->private_data;
  81         src_tcon = tlink_tcon(smb_file_src->tlink);
  82         target_tcon = tlink_tcon(smb_file_target->tlink);
  83
  84         /* check if source and target are on same tree connection */
  85         if (src_tcon != target_tcon) {
  86                 cifs_dbg(VFS, "file copy src and target on different volume\n");
  87                 goto out_fput;
  88         }
  89
  90         src_inode = file_inode(src_file.file);
  91         rc = -EINVAL;
  92         if (S_ISDIR(src_inode->i_mode))
  93                 goto out_fput;
  94
  95         /*
  96          * Note: cifs case is easier than btrfs since server responsible for
  97          * checks for proper open modes and file type and if it wants
  98          * server could even support copy of range where source = target
  99          */
 100         lock_two_nondirectories(target_inode, src_inode);
 101
 102         /* determine range to clone */
 103         rc = -EINVAL;
 104         if (off + len > src_inode->i_size || off + len < off)
 105                 goto out_unlock;
 106         if (len == 0)
 107                 len = src_inode->i_size - off;
 108
 109         cifs_dbg(FYI, "about to flush pages\n");
 110         /* should we flush first and last page first */
 111         truncate_inode_pages_range(&target_inode->i_data, destoff,
 112                                    PAGE_CACHE_ALIGN(destoff + len)-1);
 113
 114         if (dup_extents && target_tcon->ses->server->ops->duplicate_extents)
 115                 rc = target_tcon->ses->server->ops->duplicate_extents(xid,
 116                         smb_file_src, smb_file_target, off, len, destoff);
 117         else if (!dup_extents && 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         else
 121                 rc = -EOPNOTSUPP;
 122
 123         /* force revalidate of size and timestamps of target file now
 124            that target is updated on the server */
 125         CIFS_I(target_inode)->time = 0;
 126 out_unlock:
 127         /* although unlocking in the reverse order from locking is not
 128            strictly necessary here it is a little cleaner to be consistent */
 129         unlock_two_nondirectories(src_inode, target_inode);
 130 out_fput:
 131         fdput(src_file);
 132 out_drop_write:
 133         mnt_drop_write_file(dst_file);
 134         return rc;
 135 }
 136
 137 long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
 138 {
 139         struct inode *inode = file_inode(filep);
 140         int rc = -ENOTTY; /* strange error - but the precedent */
 141         unsigned int xid;
 142         struct cifs_sb_info *cifs_sb;
 143         struct cifsFileInfo *pSMBFile = filep->private_data;
 144         struct cifs_tcon *tcon;
 145         __u64   ExtAttrBits = 0;
 146         __u64   caps;
 147
 148         xid = get_xid();
 149
 150         cifs_dbg(FYI, "ioctl file %p  cmd %u  arg %lu\n", filep, command, arg);
 151
 152         cifs_sb = CIFS_SB(inode->i_sb);
 153
 154         switch (command) {
 155                 case FS_IOC_GETFLAGS:
 156                         if (pSMBFile == NULL)
 157                                 break;
 158                         tcon = tlink_tcon(pSMBFile->tlink);
 159                         caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
 160 #ifdef CONFIG_CIFS_POSIX
 161                         if (CIFS_UNIX_EXTATTR_CAP & caps) {
 162                                 __u64   ExtAttrMask = 0;
 163                                 rc = CIFSGetExtAttr(xid, tcon,
 164                                                     pSMBFile->fid.netfid,
 165                                                     &ExtAttrBits, &ExtAttrMask);
 166                                 if (rc == 0)
 167                                         rc = put_user(ExtAttrBits &
 168                                                 FS_FL_USER_VISIBLE,
 169                                                 (int __user *)arg);
 170                                 if (rc != EOPNOTSUPP)
 171                                         break;
 172                         }
 173 #endif /* CONFIG_CIFS_POSIX */
 174                         rc = 0;
 175                         if (CIFS_I(inode)->cifsAttrs & ATTR_COMPRESSED) {
 176                                 /* add in the compressed bit */
 177                                 ExtAttrBits = FS_COMPR_FL;
 178                                 rc = put_user(ExtAttrBits & FS_FL_USER_VISIBLE,
 179                                               (int __user *)arg);
 180                         }
 181                         break;
 182                 case FS_IOC_SETFLAGS:
 183                         if (pSMBFile == NULL)
 184                                 break;
 185                         tcon = tlink_tcon(pSMBFile->tlink);
 186                         caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
 187
 188                         if (get_user(ExtAttrBits, (int __user *)arg)) {
 189                                 rc = -EFAULT;
 190                                 break;
 191                         }
 192
 193                         /*
 194                          * if (CIFS_UNIX_EXTATTR_CAP & caps)
 195                          *      rc = CIFSSetExtAttr(xid, tcon,
 196                          *                     pSMBFile->fid.netfid,
 197                          *                     extAttrBits,
 198                          *                     &ExtAttrMask);
 199                          * if (rc != EOPNOTSUPP)
 200                          *      break;
 201                          */
 202
 203                         /* Currently only flag we can set is compressed flag */
 204                         if ((ExtAttrBits & FS_COMPR_FL) == 0)
 205                                 break;
 206
 207                         /* Try to set compress flag */
 208                         if (tcon->ses->server->ops->set_compression) {
 209                                 rc = tcon->ses->server->ops->set_compression(
 210                                                         xid, tcon, pSMBFile);
 211                                 cifs_dbg(FYI, "set compress flag rc %d\n", rc);
 212                         }
 213                         break;
 214                 case CIFS_IOC_COPYCHUNK_FILE:
 215                         rc = cifs_ioctl_clone(xid, filep, arg, 0, 0, 0, false);
 216                         break;
 217                 case BTRFS_IOC_CLONE:
 218                         rc = cifs_ioctl_clone(xid, filep, arg, 0, 0, 0, true);
 219                         break;
 220                 default:
 221                         cifs_dbg(FYI, "unsupported ioctl\n");
 222                         break;
 223         }
 224
 225         free_xid(xid);
 226         return rc;
 227 }