fs/cifs/smb2file.c

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