CIFS: Add SMB2 support for cifs_iovec_write
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index aef1674..330f625 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -582,6 +582,33 @@
#define CIFS_KMAP_SIZE_LIMIT (1<<24)
#endif /* CONFIG_HIGHMEM */
+#ifdef CONFIG_HIGHMEM
+/*
+ * On arches that have high memory, kmap address space is limited. By
+ * serializing the kmap operations on those arches, we ensure that we don't
+ * end up with a bunch of threads in writeback with partially mapped page
+ * arrays, stuck waiting for kmap to come back. That situation prevents
+ * progress and can deadlock.
+ */
+
+extern struct mutex cifs_kmap_mutex;
+
+static inline void
+cifs_kmap_lock(void)
+{
+ mutex_lock(&cifs_kmap_mutex);
+}
+
+static inline void
+cifs_kmap_unlock(void)
+{
+ mutex_unlock(&cifs_kmap_mutex);
+}
+#else /* !CONFIG_HIGHMEM */
+#define cifs_kmap_lock() do { ; } while (0)
+#define cifs_kmap_unlock() do { ; } while (0)
+#endif /* CONFIG_HIGHMEM */
+
/*
* Macros to allow the TCP_Server_Info->net field and related code to drop out
* when CONFIG_NET_NS isn't set.
@@ -891,6 +918,26 @@
struct kvec iov[1];
};
+struct cifs_writedata;
+
+/* asynchronous write support */
+struct cifs_writedata {
+ struct kref refcount;
+ struct list_head list;
+ struct completion done;
+ enum writeback_sync_modes sync_mode;
+ struct work_struct work;
+ struct cifsFileInfo *cfile;
+ __u64 offset;
+ pid_t pid;
+ unsigned int bytes;
+ int result;
+ void (*marshal_iov) (struct kvec *iov,
+ struct cifs_writedata *wdata);
+ unsigned int nr_pages;
+ struct page *pages[1];
+};
+
/*
* Take a reference on the file private data. Must be called with
* cifs_file_list_lock held.