CIFS: Use brlock cache for SMB2

Signed-off-by: Pavel Shilovsky <pshilovsky@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>

3 files changed, 94 insertions, 1 deletions

diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c
index a25ea02149e7..181e13d9f9db 100644
--- a/fs/cifs/smb2file.c
+++ b/fs/cifs/smb2file.c
@@ -201,3 +201,94 @@ smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
         kfree(buf);
         return rc;
 }
+
+static int
+smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
+                       struct smb2_lock_element *buf, unsigned int max_num)
+{
+        int rc = 0, stored_rc;
+        struct cifsFileInfo *cfile = fdlocks->cfile;
+        struct cifsLockInfo *li;
+        unsigned int num = 0;
+        struct smb2_lock_element *cur = buf;
+        struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+
+        list_for_each_entry(li, &fdlocks->locks, llist) {
+                cur->Length = cpu_to_le64(li->length);
+                cur->Offset = cpu_to_le64(li->offset);
+                cur->Flags = cpu_to_le32(li->type |
+                                                SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
+                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)
+                                rc = stored_rc;
+                        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)
+                        rc = stored_rc;
+        }
+
+        return rc;
+}
+
+int
+smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
+{
+        int rc = 0, stored_rc;
+        unsigned int xid;
+        unsigned int max_num, max_buf;
+        struct smb2_lock_element *buf;
+        struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
+        struct cifs_fid_locks *fdlocks;
+
+        xid = get_xid();
+        mutex_lock(&cinode->lock_mutex);
+        if (!cinode->can_cache_brlcks) {
+                mutex_unlock(&cinode->lock_mutex);
+                free_xid(xid);
+                return rc;
+        }
+
+        /*
+         * Accessing maxBuf is racy with cifs_reconnect - need to store value
+         * and check it for zero before using.
+         */
+        max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
+        if (!max_buf) {
+                mutex_unlock(&cinode->lock_mutex);
+                free_xid(xid);
+                return -EINVAL;
+        }
+
+        max_num = max_buf / sizeof(struct smb2_lock_element);
+        buf = kzalloc(max_num * sizeof(struct smb2_lock_element), GFP_KERNEL);
+        if (!buf) {
+                mutex_unlock(&cinode->lock_mutex);
+                free_xid(xid);
+                return -ENOMEM;
+        }
+
+        list_for_each_entry(fdlocks, &cinode->llist, llist) {
+                stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
+                if (stored_rc)
+                        rc = stored_rc;
+        }
+
+        cinode->can_cache_brlcks = false;
+        kfree(buf);
+
+        mutex_unlock(&cinode->lock_mutex);
+        free_xid(xid);
+        return rc;
+}
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index caed2c57896d..0808b238219b 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -371,7 +371,7 @@ smb2_set_fid(struct cifsFileInfo *cfile, struct cifs_fid *fid, __u32 oplock)
         cfile->fid.persistent_fid = fid->persistent_fid;
         cfile->fid.volatile_fid = fid->volatile_fid;
         smb2_set_oplock_level(cinode, oplock);
-        /* cinode->can_cache_brlcks = cinode->clientCanCacheAll; */
+        cinode->can_cache_brlcks = cinode->clientCanCacheAll;
 }
 
 static int
@@ -615,6 +615,7 @@ struct smb_version_operations smb21_operations = {
         .queryfs = smb2_queryfs,
         .mand_lock = smb2_mand_lock,
         .mand_unlock_range = smb2_unlock_range,
+        .push_mand_locks = smb2_push_mandatory_locks,
 };
 
 struct smb_version_values smb21_values = {
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index ab19152b092b..8b4d3712255b 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -86,6 +86,7 @@ extern int smb2_open_file(const unsigned int xid, struct cifs_tcon *tcon,
 extern void smb2_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock);
 extern int smb2_unlock_range(struct cifsFileInfo *cfile,
                              struct file_lock *flock, const unsigned int xid);
+extern int smb2_push_mandatory_locks(struct cifsFileInfo *cfile);
 
 /*
  * SMB2 Worker functions - most of protocol specific implementation details