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 <linux/btrfs.h>
  30 #include "cifspdu.h"
  31 #include "cifsglob.h"
  32 #include "cifsproto.h"
  33 #include "cifs_debug.h"
  34 #include "cifsfs.h"
  35
  36 static long cifs_ioctl_clone(unsigned int xid, struct file *dst_file,
  37                         unsigned long srcfd, u64 off, u64 len, u64 destoff)
  38 {
  39         int rc;
  40         struct cifsFileInfo *smb_file_target = dst_file->private_data;
  41         struct inode *target_inode = file_inode(dst_file);
  42         struct cifs_tcon *target_tcon;
  43         struct fd src_file;
  44         struct cifsFileInfo *smb_file_src;
  45         struct inode *src_inode;
  46         struct cifs_tcon *src_tcon;
  47
  48         cifs_dbg(FYI, "ioctl clone range\n");
  49         /* the destination must be opened for writing */
  50         if (!(dst_file->f_mode & FMODE_WRITE)) {
  51                 cifs_dbg(FYI, "file target not open for write\n");
  52                 return -EINVAL;
  53         }
  54
  55         /* check if target volume is readonly and take reference */
  56         rc = mnt_want_write_file(dst_file);
  57         if (rc) {
  58                 cifs_dbg(FYI, "mnt_want_write failed with rc %d\n", rc);
  59                 return rc;
  60         }
  61
  62         src_file = fdget(srcfd);
  63         if (!src_file.file) {
  64                 rc = -EBADF;
  65                 goto out_drop_write;
  66         }
  67
  68         if ((!src_file.file->private_data) || (!dst_file->private_data)) {
  69                 rc = -EBADF;
  70                 cifs_dbg(VFS, "missing cifsFileInfo on copy range src file\n");
  71                 goto out_fput;
  72         }
  73
  74         rc = -EXDEV;
  75         smb_file_target = dst_file->private_data;
  76         smb_file_src = src_file.file->private_data;
  77         src_tcon = tlink_tcon(smb_file_src->tlink);
  78         target_tcon = tlink_tcon(smb_file_target->tlink);
  79
  80         /* check if source and target are on same tree connection */
  81         if (src_tcon != target_tcon) {
  82                 cifs_dbg(VFS, "file copy src and target on different volume\n");
  83                 goto out_fput;
  84         }
  85
  86         src_inode = src_file.file->f_dentry->d_inode;
  87
  88         /*
  89          * Note: cifs case is easier than btrfs since server responsible for
  90          * checks for proper open modes and file type and if it wants
  91          * server could even support copy of range where source = target
  92          */
  93
  94         /* so we do not deadlock racing two ioctls on same files */
  95         if (target_inode < src_inode) {
  96                 mutex_lock_nested(&target_inode->i_mutex, I_MUTEX_PARENT);
  97                 mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_CHILD);
  98         } else {
  99                 mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_PARENT);
 100                 mutex_lock_nested(&target_inode->i_mutex, I_MUTEX_CHILD);
 101         }
 102
 103         /* determine range to clone */
 104         rc = -EINVAL;
 105         if (off + len > src_inode->i_size || off + len < off)
 106                 goto out_unlock;
 107         if (len == 0)
 108                 len = src_inode->i_size - off;
 109
 110         cifs_dbg(FYI, "about to flush pages\n");
 111         /* should we flush first and last page first */
 112         truncate_inode_pages_range(&target_inode->i_data, destoff,
 113                                    PAGE_CACHE_ALIGN(destoff + len)-1);
 114
 115         if (target_tcon->ses->server->ops->clone_range)
 116                 rc = target_tcon->ses->server->ops->clone_range(xid,
 117                         smb_file_src, smb_file_target, off, len, destoff);
 118
 119         /* force revalidate of size and timestamps of target file now
 120            that target is updated on the server */
 121         CIFS_I(target_inode)->time = 0;
 122 out_unlock:
 123         /* although unlocking in the reverse order from locking is not
 124            strictly necessary here it is a little cleaner to be consistent */
 125         if (target_inode < src_inode) {
 126                 mutex_unlock(&src_inode->i_mutex);
 127                 mutex_unlock(&target_inode->i_mutex);
 128         } else {
 129                 mutex_unlock(&target_inode->i_mutex);
 130                 mutex_unlock(&src_inode->i_mutex);
 131         }
 132 out_fput:
 133         fdput(src_file);
 134 out_drop_write:
 135         mnt_drop_write_file(dst_file);
 136         return rc;
 137 }
 138
 139 long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
 140 {
 141         struct inode *inode = file_inode(filep);
 142         int rc = -ENOTTY; /* strange error - but the precedent */
 143         unsigned int xid;
 144         struct cifs_sb_info *cifs_sb;
 145         struct cifsFileInfo *pSMBFile = filep->private_data;
 146         struct cifs_tcon *tcon;
 147         __u64   ExtAttrBits = 0;
 148         __u64   caps;
 149
 150         xid = get_xid();
 151
 152         cifs_dbg(FYI, "ioctl file %p  cmd %u  arg %lu\n", filep, command, arg);
 153
 154         cifs_sb = CIFS_SB(inode->i_sb);
 155
 156         switch (command) {
 157                 case FS_IOC_GETFLAGS:
 158                         if (pSMBFile == NULL)
 159                                 break;
 160                         tcon = tlink_tcon(pSMBFile->tlink);
 161                         caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
 162 #ifdef CONFIG_CIFS_POSIX
 163                         if (CIFS_UNIX_EXTATTR_CAP & caps) {
 164                                 __u64   ExtAttrMask = 0;
 165                                 rc = CIFSGetExtAttr(xid, tcon,
 166                                                     pSMBFile->fid.netfid,
 167                                                     &ExtAttrBits, &ExtAttrMask);
 168                                 if (rc == 0)
 169                                         rc = put_user(ExtAttrBits &
 170                                                 FS_FL_USER_VISIBLE,
 171                                                 (int __user *)arg);
 172                                 if (rc != EOPNOTSUPP)
 173                                         break;
 174                         }
 175 #endif /* CONFIG_CIFS_POSIX */
 176                         rc = 0;
 177                         if (CIFS_I(inode)->cifsAttrs & ATTR_COMPRESSED) {
 178                                 /* add in the compressed bit */
 179                                 ExtAttrBits = FS_COMPR_FL;
 180                                 rc = put_user(ExtAttrBits & FS_FL_USER_VISIBLE,
 181                                               (int __user *)arg);
 182                         }
 183                         break;
 184                 case FS_IOC_SETFLAGS:
 185                         if (pSMBFile == NULL)
 186                                 break;
 187                         tcon = tlink_tcon(pSMBFile->tlink);
 188                         caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
 189
 190                         if (get_user(ExtAttrBits, (int __user *)arg)) {
 191                                 rc = -EFAULT;
 192                                 break;
 193                         }
 194
 195                         /*
 196                          * if (CIFS_UNIX_EXTATTR_CAP & caps)
 197                          *      rc = CIFSSetExtAttr(xid, tcon,
 198                          *                     pSMBFile->fid.netfid,
 199                          *                     extAttrBits,
 200                          *                     &ExtAttrMask);
 201                          * if (rc != EOPNOTSUPP)
 202                          *      break;
 203                          */
 204
 205                         /* Currently only flag we can set is compressed flag */
 206                         if ((ExtAttrBits & FS_COMPR_FL) == 0)
 207                                 break;
 208
 209                         /* Try to set compress flag */
 210                         if (tcon->ses->server->ops->set_compression) {
 211                                 rc = tcon->ses->server->ops->set_compression(
 212                                                         xid, tcon, pSMBFile);
 213                                 cifs_dbg(FYI, "set compress flag rc %d\n", rc);
 214                         }
 215                         break;
 216                 case BTRFS_IOC_CLONE:
 217                         rc = cifs_ioctl_clone(xid, filep, arg, 0, 0, 0);
 218                         break;
 219                 default:
 220                         cifs_dbg(FYI, "unsupported ioctl\n");
 221                         break;
 222         }
 223
 224         free_xid(xid);
 225         return rc;
 226 }