CIFS: Add brlock support for SMB2
Signed-off-by: Pavel Shilovsky <pshilovsky@etersoft.ru>
diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c
index 5ff25e0..a25ea02 100644
--- a/fs/cifs/smb2file.c
+++ b/fs/cifs/smb2file.c
@@ -104,3 +104,100 @@
kfree(smb2_path);
return rc;
}
+
+int
+smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
+ const unsigned int xid)
+{
+ int rc = 0, stored_rc;
+ unsigned int max_num, num = 0, max_buf;
+ struct smb2_lock_element *buf, *cur;
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+ struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
+ struct cifsLockInfo *li, *tmp;
+ __u64 length = 1 + flock->fl_end - flock->fl_start;
+ struct list_head tmp_llist;
+
+ INIT_LIST_HEAD(&tmp_llist);
+
+ /*
+ * Accessing maxBuf is racy with cifs_reconnect - need to store value
+ * and check it for zero before using.
+ */
+ max_buf = tcon->ses->server->maxBuf;
+ if (!max_buf)
+ return -EINVAL;
+
+ max_num = max_buf / sizeof(struct smb2_lock_element);
+ buf = kzalloc(max_num * sizeof(struct smb2_lock_element), GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ cur = buf;
+
+ mutex_lock(&cinode->lock_mutex);
+ list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
+ if (flock->fl_start > li->offset ||
+ (flock->fl_start + length) <
+ (li->offset + li->length))
+ continue;
+ if (current->tgid != li->pid)
+ continue;
+ if (cinode->can_cache_brlcks) {
+ /*
+ * We can cache brlock requests - simply remove a lock
+ * from the file's list.
+ */
+ list_del(&li->llist);
+ cifs_del_lock_waiters(li);
+ kfree(li);
+ continue;
+ }
+ cur->Length = cpu_to_le64(li->length);
+ cur->Offset = cpu_to_le64(li->offset);
+ cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
+ /*
+ * We need to save a lock here to let us add it again to the
+ * file's list if the unlock range request fails on the server.
+ */
+ list_move(&li->llist, &tmp_llist);
+ if (++num == max_num) {
+ stored_rc = smb2_lockv(xid, tcon,
+ cfile->fid.persistent_fid,
+ cfile->fid.volatile_fid,
+ current->tgid, num, buf);
+ if (stored_rc) {
+ /*
+ * We failed on the unlock range request - add
+ * all locks from the tmp list to the head of
+ * the file's list.
+ */
+ cifs_move_llist(&tmp_llist,
+ &cfile->llist->locks);
+ rc = stored_rc;
+ } else
+ /*
+ * The unlock range request succeed - free the
+ * tmp list.
+ */
+ cifs_free_llist(&tmp_llist);
+ cur = buf;
+ num = 0;
+ } else
+ cur++;
+ }
+ if (num) {
+ stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
+ cfile->fid.volatile_fid, current->tgid,
+ num, buf);
+ if (stored_rc) {
+ cifs_move_llist(&tmp_llist, &cfile->llist->locks);
+ rc = stored_rc;
+ } else
+ cifs_free_llist(&tmp_llist);
+ }
+ mutex_unlock(&cinode->lock_mutex);
+
+ kfree(buf);
+ return rc;
+}