root/fs/cifs/smb2file.c

DEFINITIONS

1. smb2_open_file
2. smb2_unlock_range
3. smb2_push_mand_fdlocks
4. smb2_push_mandatory_locks

   1 /*
   2  *   fs/cifs/smb2file.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002, 2011
   5  *   Author(s): Steve French (sfrench@us.ibm.com),
   6  *              Pavel Shilovsky ((pshilovsky@samba.org) 2012
   7  *
   8  *   This library is free software; you can redistribute it and/or modify
   9  *   it under the terms of the GNU Lesser General Public License as published
  10  *   by the Free Software Foundation; either version 2.1 of the License, or
  11  *   (at your option) any later version.
  12  *
  13  *   This library is distributed in the hope that it will be useful,
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  16  *   the GNU Lesser General Public License for more details.
  17  *
  18  *   You should have received a copy of the GNU Lesser General Public License
  19  *   along with this library; if not, write to the Free Software
  20  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21  */
  22 #include <linux/fs.h>
  23 #include <linux/stat.h>
  24 #include <linux/slab.h>
  25 #include <linux/pagemap.h>
  26 #include <asm/div64.h>
  27 #include "cifsfs.h"
  28 #include "cifspdu.h"
  29 #include "cifsglob.h"
  30 #include "cifsproto.h"
  31 #include "cifs_debug.h"
  32 #include "cifs_fs_sb.h"
  33 #include "cifs_unicode.h"
  34 #include "fscache.h"
  35 #include "smb2proto.h"
  36 
  37 int
  38 smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
  39                __u32 *oplock, FILE_ALL_INFO *buf)
  40 {
  41         int rc;
  42         __le16 *smb2_path;
  43         struct smb2_file_all_info *smb2_data = NULL;
  44         __u8 smb2_oplock;
  45         struct cifs_fid *fid = oparms->fid;
  46         struct network_resiliency_req nr_ioctl_req;
  47 
  48         smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
  49         if (smb2_path == NULL) {
  50                 rc = -ENOMEM;
  51                 goto out;
  52         }
  53 
  54         smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
  55                             GFP_KERNEL);
  56         if (smb2_data == NULL) {
  57                 rc = -ENOMEM;
  58                 goto out;
  59         }
  60 
  61         oparms->desired_access |= FILE_READ_ATTRIBUTES;
  62         smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
  63 
  64         rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL,
  65                        NULL);
  66         if (rc)
  67                 goto out;
  68 
  69 
  70         if (oparms->tcon->use_resilient) {
  71                 /* default timeout is 0, servers pick default (120 seconds) */
  72                 nr_ioctl_req.Timeout =
  73                         cpu_to_le32(oparms->tcon->handle_timeout);
  74                 nr_ioctl_req.Reserved = 0;
  75                 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
  76                         fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
  77                         true /* is_fsctl */,
  78                         (char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
  79                         CIFSMaxBufSize, NULL, NULL /* no return info */);
  80                 if (rc == -EOPNOTSUPP) {
  81                         cifs_dbg(VFS,
  82                              "resiliency not supported by server, disabling\n");
  83                         oparms->tcon->use_resilient = false;
  84                 } else if (rc)
  85                         cifs_dbg(FYI, "error %d setting resiliency\n", rc);
  86 
  87                 rc = 0;
  88         }
  89 
  90         if (buf) {
  91                 /* if open response does not have IndexNumber field - get it */
  92                 if (smb2_data->IndexNumber == 0) {
  93                         rc = SMB2_get_srv_num(xid, oparms->tcon,
  94                                       fid->persistent_fid,
  95                                       fid->volatile_fid,
  96                                       &smb2_data->IndexNumber);
  97                         if (rc) {
  98                                 /*
  99                                  * let get_inode_info disable server inode
 100                                  * numbers
 101                                  */
 102                                 smb2_data->IndexNumber = 0;
 103                                 rc = 0;
 104                         }
 105                 }
 106                 move_smb2_info_to_cifs(buf, smb2_data);
 107         }
 108 
 109         *oplock = smb2_oplock;
 110 out:
 111         kfree(smb2_data);
 112         kfree(smb2_path);
 113         return rc;
 114 }
 115 
 116 int
 117 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 118                   const unsigned int xid)
 119 {
 120         int rc = 0, stored_rc;
 121         unsigned int max_num, num = 0, max_buf;
 122         struct smb2_lock_element *buf, *cur;
 123         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 124         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 125         struct cifsLockInfo *li, *tmp;
 126         __u64 length = 1 + flock->fl_end - flock->fl_start;
 127         struct list_head tmp_llist;
 128 
 129         INIT_LIST_HEAD(&tmp_llist);
 130 
 131         /*
 132          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 133          * and check it before using.
 134          */
 135         max_buf = tcon->ses->server->maxBuf;
 136         if (max_buf < sizeof(struct smb2_lock_element))
 137                 return -EINVAL;
 138 
 139         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 140         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 141         max_num = max_buf / sizeof(struct smb2_lock_element);
 142         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 143         if (!buf)
 144                 return -ENOMEM;
 145 
 146         cur = buf;
 147 
 148         cifs_down_write(&cinode->lock_sem);
 149         list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
 150                 if (flock->fl_start > li->offset ||
 151                     (flock->fl_start + length) <
 152                     (li->offset + li->length))
 153                         continue;
 154                 if (current->tgid != li->pid)
 155                         continue;
 156                 if (cinode->can_cache_brlcks) {
 157                         /*
 158                          * We can cache brlock requests - simply remove a lock
 159                          * from the file's list.
 160                          */
 161                         list_del(&li->llist);
 162                         cifs_del_lock_waiters(li);
 163                         kfree(li);
 164                         continue;
 165                 }
 166                 cur->Length = cpu_to_le64(li->length);
 167                 cur->Offset = cpu_to_le64(li->offset);
 168                 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
 169                 /*
 170                  * We need to save a lock here to let us add it again to the
 171                  * file's list if the unlock range request fails on the server.
 172                  */
 173                 list_move(&li->llist, &tmp_llist);
 174                 if (++num == max_num) {
 175                         stored_rc = smb2_lockv(xid, tcon,
 176                                                cfile->fid.persistent_fid,
 177                                                cfile->fid.volatile_fid,
 178                                                current->tgid, num, buf);
 179                         if (stored_rc) {
 180                                 /*
 181                                  * We failed on the unlock range request - add
 182                                  * all locks from the tmp list to the head of
 183                                  * the file's list.
 184                                  */
 185                                 cifs_move_llist(&tmp_llist,
 186                                                 &cfile->llist->locks);
 187                                 rc = stored_rc;
 188                         } else
 189                                 /*
 190                                  * The unlock range request succeed - free the
 191                                  * tmp list.
 192                                  */
 193                                 cifs_free_llist(&tmp_llist);
 194                         cur = buf;
 195                         num = 0;
 196                 } else
 197                         cur++;
 198         }
 199         if (num) {
 200                 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
 201                                        cfile->fid.volatile_fid, current->tgid,
 202                                        num, buf);
 203                 if (stored_rc) {
 204                         cifs_move_llist(&tmp_llist, &cfile->llist->locks);
 205                         rc = stored_rc;
 206                 } else
 207                         cifs_free_llist(&tmp_llist);
 208         }
 209         up_write(&cinode->lock_sem);
 210 
 211         kfree(buf);
 212         return rc;
 213 }
 214 
 215 static int
 216 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
 217                        struct smb2_lock_element *buf, unsigned int max_num)
 218 {
 219         int rc = 0, stored_rc;
 220         struct cifsFileInfo *cfile = fdlocks->cfile;
 221         struct cifsLockInfo *li;
 222         unsigned int num = 0;
 223         struct smb2_lock_element *cur = buf;
 224         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 225 
 226         list_for_each_entry(li, &fdlocks->locks, llist) {
 227                 cur->Length = cpu_to_le64(li->length);
 228                 cur->Offset = cpu_to_le64(li->offset);
 229                 cur->Flags = cpu_to_le32(li->type |
 230                                                 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
 231                 if (++num == max_num) {
 232                         stored_rc = smb2_lockv(xid, tcon,
 233                                                cfile->fid.persistent_fid,
 234                                                cfile->fid.volatile_fid,
 235                                                current->tgid, num, buf);
 236                         if (stored_rc)
 237                                 rc = stored_rc;
 238                         cur = buf;
 239                         num = 0;
 240                 } else
 241                         cur++;
 242         }
 243         if (num) {
 244                 stored_rc = smb2_lockv(xid, tcon,
 245                                        cfile->fid.persistent_fid,
 246                                        cfile->fid.volatile_fid,
 247                                        current->tgid, num, buf);
 248                 if (stored_rc)
 249                         rc = stored_rc;
 250         }
 251 
 252         return rc;
 253 }
 254 
 255 int
 256 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
 257 {
 258         int rc = 0, stored_rc;
 259         unsigned int xid;
 260         unsigned int max_num, max_buf;
 261         struct smb2_lock_element *buf;
 262         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 263         struct cifs_fid_locks *fdlocks;
 264 
 265         xid = get_xid();
 266 
 267         /*
 268          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 269          * and check it for zero before using.
 270          */
 271         max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
 272         if (max_buf < sizeof(struct smb2_lock_element)) {
 273                 free_xid(xid);
 274                 return -EINVAL;
 275         }
 276 
 277         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 278         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 279         max_num = max_buf / sizeof(struct smb2_lock_element);
 280         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 281         if (!buf) {
 282                 free_xid(xid);
 283                 return -ENOMEM;
 284         }
 285 
 286         list_for_each_entry(fdlocks, &cinode->llist, llist) {
 287                 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
 288                 if (stored_rc)
 289                         rc = stored_rc;
 290         }
 291 
 292         kfree(buf);
 293         free_xid(xid);
 294         return rc;
 295 }