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authorAlasdair G Kergon <agk@redhat.com>2008-04-25 01:02:01 +0400
committerAlasdair G Kergon <agk@redhat.com>2008-04-25 16:26:55 +0400
commita765e20eeb423d0fa6a02ffab51141e53bbd93cb (patch)
treefc7279fa73a21518373e1ba2efad27dab89a2214 /include/linux/dm-io.h
parent2d1e580afe23287871529ce54429e249809525a1 (diff)
downloadlinux-a765e20eeb423d0fa6a02ffab51141e53bbd93cb.tar.xz
dm: move include files
Publish the dm-io, dm-log and dm-kcopyd headers in include/linux. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'include/linux/dm-io.h')
-rw-r--r--include/linux/dm-io.h85
1 files changed, 85 insertions, 0 deletions
diff --git a/include/linux/dm-io.h b/include/linux/dm-io.h
new file mode 100644
index 000000000000..b6bf17ee2f61
--- /dev/null
+++ b/include/linux/dm-io.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2003 Sistina Software
+ * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
+ *
+ * Device-Mapper low-level I/O.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef _LINUX_DM_IO_H
+#define _LINUX_DM_IO_H
+
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+
+struct dm_io_region {
+ struct block_device *bdev;
+ sector_t sector;
+ sector_t count; /* If this is zero the region is ignored. */
+};
+
+struct page_list {
+ struct page_list *next;
+ struct page *page;
+};
+
+typedef void (*io_notify_fn)(unsigned long error, void *context);
+
+enum dm_io_mem_type {
+ DM_IO_PAGE_LIST,/* Page list */
+ DM_IO_BVEC, /* Bio vector */
+ DM_IO_VMA, /* Virtual memory area */
+ DM_IO_KMEM, /* Kernel memory */
+};
+
+struct dm_io_memory {
+ enum dm_io_mem_type type;
+
+ union {
+ struct page_list *pl;
+ struct bio_vec *bvec;
+ void *vma;
+ void *addr;
+ } ptr;
+
+ unsigned offset;
+};
+
+struct dm_io_notify {
+ io_notify_fn fn; /* Callback for asynchronous requests */
+ void *context; /* Passed to callback */
+};
+
+/*
+ * IO request structure
+ */
+struct dm_io_client;
+struct dm_io_request {
+ int bi_rw; /* READ|WRITE - not READA */
+ struct dm_io_memory mem; /* Memory to use for io */
+ struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */
+ struct dm_io_client *client; /* Client memory handler */
+};
+
+/*
+ * For async io calls, users can alternatively use the dm_io() function below
+ * and dm_io_client_create() to create private mempools for the client.
+ *
+ * Create/destroy may block.
+ */
+struct dm_io_client *dm_io_client_create(unsigned num_pages);
+int dm_io_client_resize(unsigned num_pages, struct dm_io_client *client);
+void dm_io_client_destroy(struct dm_io_client *client);
+
+/*
+ * IO interface using private per-client pools.
+ * Each bit in the optional 'sync_error_bits' bitset indicates whether an
+ * error occurred doing io to the corresponding region.
+ */
+int dm_io(struct dm_io_request *io_req, unsigned num_regions,
+ struct dm_io_region *region, unsigned long *sync_error_bits);
+
+#endif /* __KERNEL__ */
+#endif /* _LINUX_DM_IO_H */