dm bufio: move dm-bufio.h to include/linux/

Move dm-bufio.h to include/linux/ so that external GPL'd DM target
modules can use it.

It is better to allow the use of dm-bufio than force external modules
to implement the equivalent buffered IO mechanism in some new way.  The
hope is this will encourage the use of dm-bufio; which will then make it
easier for a GPL'd external DM target module to be included upstream.

A couple dm-bufio EXPORT_SYMBOL exports have also been updated to use
EXPORT_SYMBOL_GPL.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

6 files changed, 8 insertions, 156 deletions

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index f5360a6260ff..87795a361d09 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -6,7 +6,7 @@
  * This file is released under the GPL.
  */
 
-#include "dm-bufio.h"
+#include <linux/dm-bufio.h>
 
 #include <linux/device-mapper.h>
 #include <linux/dm-io.h>
@@ -1478,13 +1478,13 @@ void dm_bufio_forget(struct dm_bufio_client *c, sector_t block)
 
 	dm_bufio_unlock(c);
 }
-EXPORT_SYMBOL(dm_bufio_forget);
+EXPORT_SYMBOL_GPL(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);
+EXPORT_SYMBOL_GPL(dm_bufio_set_minimum_buffers);
 
 unsigned dm_bufio_get_block_size(struct dm_bufio_client *c)
 {
@@ -1690,7 +1690,7 @@ 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;
+	dm_bufio_set_minimum_buffers(c, DM_BUFIO_MIN_BUFFERS);
 
 	init_waitqueue_head(&c->free_buffer_wait);
 	c->async_write_error = 0;
diff --git a/drivers/md/dm-bufio.h b/drivers/md/dm-bufio.h
deleted file mode 100644
index be732d3f8611..000000000000
--- a/drivers/md/dm-bufio.h
+++ /dev/null
@@ -1,148 +0,0 @@
-/*
- * Copyright (C) 2009-2011 Red Hat, Inc.
- *
- * Author: Mikulas Patocka <mpatocka@redhat.com>
- *
- * This file is released under the GPL.
- */
-
-#ifndef DM_BUFIO_H
-#define DM_BUFIO_H
-
-#include <linux/blkdev.h>
-#include <linux/types.h>
-
-/*----------------------------------------------------------------*/
-
-struct dm_bufio_client;
-struct dm_buffer;
-
-/*
- * Create a buffered IO cache on a given device
- */
-struct dm_bufio_client *
-dm_bufio_client_create(struct block_device *bdev, unsigned block_size,
-		       unsigned reserved_buffers, unsigned aux_size,
-		       void (*alloc_callback)(struct dm_buffer *),
-		       void (*write_callback)(struct dm_buffer *));
-
-/*
- * Release a buffered IO cache.
- */
-void dm_bufio_client_destroy(struct dm_bufio_client *c);
-
-/*
- * Set the sector range.
- * When this function is called, there must be no I/O in progress on the bufio
- * client.
- */
-void dm_bufio_set_sector_offset(struct dm_bufio_client *c, sector_t start);
-
-/*
- * WARNING: to avoid deadlocks, these conditions are observed:
- *
- * - At most one thread can hold at most "reserved_buffers" simultaneously.
- * - Each other threads can hold at most one buffer.
- * - Threads which call only dm_bufio_get can hold unlimited number of
- *   buffers.
- */
-
-/*
- * Read a given block from disk. Returns pointer to data.  Returns a
- * pointer to dm_buffer that can be used to release the buffer or to make
- * it dirty.
- */
-void *dm_bufio_read(struct dm_bufio_client *c, sector_t block,
-		    struct dm_buffer **bp);
-
-/*
- * Like dm_bufio_read, but return buffer from cache, don't read
- * it. If the buffer is not in the cache, return NULL.
- */
-void *dm_bufio_get(struct dm_bufio_client *c, sector_t block,
-		   struct dm_buffer **bp);
-
-/*
- * Like dm_bufio_read, but don't read anything from the disk.  It is
- * expected that the caller initializes the buffer and marks it dirty.
- */
-void *dm_bufio_new(struct dm_bufio_client *c, sector_t block,
-		   struct dm_buffer **bp);
-
-/*
- * Prefetch the specified blocks to the cache.
- * The function starts to read the blocks and returns without waiting for
- * I/O to finish.
- */
-void dm_bufio_prefetch(struct dm_bufio_client *c,
-		       sector_t block, unsigned n_blocks);
-
-/*
- * Release a reference obtained with dm_bufio_{read,get,new}. The data
- * pointer and dm_buffer pointer is no longer valid after this call.
- */
-void dm_bufio_release(struct dm_buffer *b);
-
-/*
- * Mark a buffer dirty. It should be called after the buffer is modified.
- *
- * In case of memory pressure, the buffer may be written after
- * dm_bufio_mark_buffer_dirty, but before dm_bufio_write_dirty_buffers.  So
- * dm_bufio_write_dirty_buffers guarantees that the buffer is on-disk but
- * the actual writing may occur earlier.
- */
-void dm_bufio_mark_buffer_dirty(struct dm_buffer *b);
-
-/*
- * Mark a part of the buffer dirty.
- *
- * The specified part of the buffer is scheduled to be written. dm-bufio may
- * write the specified part of the buffer or it may write a larger superset.
- */
-void dm_bufio_mark_partial_buffer_dirty(struct dm_buffer *b,
-					unsigned start, unsigned end);
-
-/*
- * Initiate writing of dirty buffers, without waiting for completion.
- */
-void dm_bufio_write_dirty_buffers_async(struct dm_bufio_client *c);
-
-/*
- * Write all dirty buffers. Guarantees that all dirty buffers created prior
- * to this call are on disk when this call exits.
- */
-int dm_bufio_write_dirty_buffers(struct dm_bufio_client *c);
-
-/*
- * Send an empty write barrier to the device to flush hardware disk cache.
- */
-int dm_bufio_issue_flush(struct dm_bufio_client *c);
-
-/*
- * Like dm_bufio_release but also move the buffer to the new
- * block. dm_bufio_write_dirty_buffers is needed to commit the new block.
- */
-void dm_bufio_release_move(struct dm_buffer *b, sector_t new_block);
-
-/*
- * 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);
-
-/*
- * Set the minimum number of buffers before cleanup happens.
- */
-void dm_bufio_set_minimum_buffers(struct dm_bufio_client *c, unsigned n);
-
-unsigned dm_bufio_get_block_size(struct dm_bufio_client *c);
-sector_t dm_bufio_get_device_size(struct dm_bufio_client *c);
-sector_t dm_bufio_get_block_number(struct dm_buffer *b);
-void *dm_bufio_get_block_data(struct dm_buffer *b);
-void *dm_bufio_get_aux_data(struct dm_buffer *b);
-struct dm_bufio_client *dm_bufio_get_client(struct dm_buffer *b);
-
-/*----------------------------------------------------------------*/
-
-#endif
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 6c81b11d0521..77d9fe58dae2 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -18,7 +18,7 @@
 #include <crypto/hash.h>
 #include <crypto/skcipher.h>
 #include <linux/async_tx.h>
-#include "dm-bufio.h"
+#include <linux/dm-bufio.h>
 
 #define DM_MSG_PREFIX "integrity"
 
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index c5534d294773..3c50c4e4da8f 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -14,7 +14,7 @@
 #include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/dm-io.h>
-#include "dm-bufio.h"
+#include <linux/dm-bufio.h>
 
 #define DM_MSG_PREFIX "persistent snapshot"
 #define DM_CHUNK_SIZE_DEFAULT_SECTORS 32	/* 16KB */
diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h
index b675bc015512..69f9a298f8c9 100644
--- a/drivers/md/dm-verity.h
+++ b/drivers/md/dm-verity.h
@@ -12,7 +12,7 @@
 #ifndef DM_VERITY_H
 #define DM_VERITY_H
 
-#include "dm-bufio.h"
+#include <linux/dm-bufio.h>
 #include <linux/device-mapper.h>
 #include <crypto/hash.h>
 
diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c
index ea15d220ced7..492a3f8ac119 100644
--- a/drivers/md/persistent-data/dm-block-manager.c
+++ b/drivers/md/persistent-data/dm-block-manager.c
@@ -5,8 +5,8 @@
  */
 #include "dm-block-manager.h"
 #include "dm-persistent-data-internal.h"
-#include "../dm-bufio.h"
 
+#include <linux/dm-bufio.h>
 #include <linux/crc32c.h>
 #include <linux/module.h>
 #include <linux/slab.h>