Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block

[~andy/linux] / drivers / md / dm-bufio.c

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index a1b58a65d8ed849ecef2217e1b93f2a5d3e42ba1..66c5d130c8c24c4f3101ce78296460da4487f38b 100644 (file)
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -104,6 +104,8 @@ struct dm_bufio_client {
        struct list_head reserved_buffers;
        unsigned need_reserved_buffers;
 
+       unsigned minimum_buffers;
+
        struct hlist_head *cache_hash;
        wait_queue_head_t free_buffer_wait;
 
@@ -861,8 +863,8 @@ static void __get_memory_limit(struct dm_bufio_client *c,
        buffers = dm_bufio_cache_size_per_client >>
                  (c->sectors_per_block_bits + SECTOR_SHIFT);
 
-       if (buffers < DM_BUFIO_MIN_BUFFERS)
-               buffers = DM_BUFIO_MIN_BUFFERS;
+       if (buffers < c->minimum_buffers)
+               buffers = c->minimum_buffers;
 
        *limit_buffers = buffers;
        *threshold_buffers = buffers * DM_BUFIO_WRITEBACK_PERCENT / 100;
@@ -1350,6 +1352,34 @@ retry:
 }
 EXPORT_SYMBOL_GPL(dm_bufio_release_move);
 
+/*
+ * Free the given buffer.
+ *
+ * This is just a hint, if the buffer is in use or dirty, this function
+ * does nothing.
+ */
+void dm_bufio_forget(struct dm_bufio_client *c, sector_t block)
+{
+       struct dm_buffer *b;
+
+       dm_bufio_lock(c);
+
+       b = __find(c, block);
+       if (b && likely(!b->hold_count) && likely(!b->state)) {
+               __unlink_buffer(b);
+               __free_buffer_wake(b);
+       }
+
+       dm_bufio_unlock(c);
+}
+EXPORT_SYMBOL(dm_bufio_forget);
+
+void dm_bufio_set_minimum_buffers(struct dm_bufio_client *c, unsigned n)
+{
+       c->minimum_buffers = n;
+}
+EXPORT_SYMBOL(dm_bufio_set_minimum_buffers);
+
 unsigned dm_bufio_get_block_size(struct dm_bufio_client *c)
 {
        return c->block_size;
@@ -1546,6 +1576,8 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
        INIT_LIST_HEAD(&c->reserved_buffers);
        c->need_reserved_buffers = reserved_buffers;
 
+       c->minimum_buffers = DM_BUFIO_MIN_BUFFERS;
+
        init_waitqueue_head(&c->free_buffer_wait);
        c->async_write_error = 0;