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Commit 400a0bef authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Mike Snitzer
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dm bufio: add sector start offset to dm-bufio interface 



Introduce dm_bufio_set_sector_offset() interface to allow setting a
sector offset for a dm-bufio client.  This is a prereq for the DM
integrity target.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMilan Broz <gmazyland@gmail.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 9b4b5a79

drivers/md/dm-bufio.c

+32 −19
Original line number Diff line number Diff line
@@ -110,6 +110,8 @@ struct dm_bufio_client { 
	struct rb_root buffer_tree;

	wait_queue_head_t free_buffer_wait;



	sector_t start;



	int async_write_error;



	struct list_head client_list;
@@ -557,8 +559,8 @@ static void dmio_complete(unsigned long error, void *context) 
	b->bio.bi_end_io(&b->bio);

}



static void use_dmio(struct dm_buffer *b, int rw, sector_t block,

		     bio_end_io_t *end_io)

static void use_dmio(struct dm_buffer *b, int rw, sector_t sector,

		     unsigned n_sectors, bio_end_io_t *end_io)

{

	int r;

	struct dm_io_request io_req = {
@@ -570,8 +572,8 @@ static void use_dmio(struct dm_buffer *b, int rw, sector_t block, 
	};

	struct dm_io_region region = {

		.bdev = b->c->bdev,

		.sector = block << b->c->sectors_per_block_bits,

		.count = b->c->block_size >> SECTOR_SHIFT,

		.sector = sector,

		.count = n_sectors,

	};



	if (b->data_mode != DATA_MODE_VMALLOC) {
@@ -606,14 +608,14 @@ static void inline_endio(struct bio *bio) 
	end_fn(bio);

}



static void use_inline_bio(struct dm_buffer *b, int rw, sector_t block,

			   bio_end_io_t *end_io)

static void use_inline_bio(struct dm_buffer *b, int rw, sector_t sector,

			   unsigned n_sectors, bio_end_io_t *end_io)

{

	char *ptr;

	int len;



	bio_init(&b->bio, b->bio_vec, DM_BUFIO_INLINE_VECS);

	b->bio.bi_iter.bi_sector = block << b->c->sectors_per_block_bits;

	b->bio.bi_iter.bi_sector = sector;

	b->bio.bi_bdev = b->c->bdev;

	b->bio.bi_end_io = inline_endio;

	/*
@@ -628,7 +630,7 @@ static void use_inline_bio(struct dm_buffer *b, int rw, sector_t block, 
	 * If len < PAGE_SIZE the buffer doesn't cross page boundary.

	 */

	ptr = b->data;

	len = b->c->block_size;

	len = n_sectors << SECTOR_SHIFT;



	if (len >= PAGE_SIZE)

		BUG_ON((unsigned long)ptr & (PAGE_SIZE - 1));
@@ -640,7 +642,7 @@ static void use_inline_bio(struct dm_buffer *b, int rw, sector_t block, 
				  len < PAGE_SIZE ? len : PAGE_SIZE,

				  offset_in_page(ptr))) {

			BUG_ON(b->c->block_size <= PAGE_SIZE);

			use_dmio(b, rw, block, end_io);

			use_dmio(b, rw, sector, n_sectors, end_io);

			return;

		}
@@ -651,17 +653,22 @@ static void use_inline_bio(struct dm_buffer *b, int rw, sector_t block, 
	submit_bio(&b->bio);

}



static void submit_io(struct dm_buffer *b, int rw, sector_t block,

		      bio_end_io_t *end_io)

static void submit_io(struct dm_buffer *b, int rw, bio_end_io_t *end_io)

{

	unsigned n_sectors;

	sector_t sector;



	if (rw == WRITE && b->c->write_callback)

		b->c->write_callback(b);



	if (b->c->block_size <= DM_BUFIO_INLINE_VECS * PAGE_SIZE &&

	sector = (b->block << b->c->sectors_per_block_bits) + b->c->start;

	n_sectors = 1 << b->c->sectors_per_block_bits;



	if (n_sectors <= ((DM_BUFIO_INLINE_VECS * PAGE_SIZE) >> SECTOR_SHIFT) &&

	    b->data_mode != DATA_MODE_VMALLOC)

		use_inline_bio(b, rw, block, end_io);

		use_inline_bio(b, rw, sector, n_sectors, end_io);

	else

		use_dmio(b, rw, block, end_io);

		use_dmio(b, rw, sector, n_sectors, end_io);

}



/*----------------------------------------------------------------
@@ -713,7 +720,7 @@ static void __write_dirty_buffer(struct dm_buffer *b, 
	wait_on_bit_lock_io(&b->state, B_WRITING, TASK_UNINTERRUPTIBLE);



	if (!write_list)

		submit_io(b, WRITE, b->block, write_endio);

		submit_io(b, WRITE, write_endio);

	else

		list_add_tail(&b->write_list, write_list);

}
@@ -726,7 +733,7 @@ static void __flush_write_list(struct list_head *write_list) 
		struct dm_buffer *b =

			list_entry(write_list->next, struct dm_buffer, write_list);

		list_del(&b->write_list);

		submit_io(b, WRITE, b->block, write_endio);

		submit_io(b, WRITE, write_endio);

		cond_resched();

	}

	blk_finish_plug(&plug);
@@ -1094,7 +1101,7 @@ static void *new_read(struct dm_bufio_client *c, sector_t block, 
		return NULL;



	if (need_submit)

		submit_io(b, READ, b->block, read_endio);

		submit_io(b, READ, read_endio);



	wait_on_bit_io(&b->state, B_READING, TASK_UNINTERRUPTIBLE);
@@ -1164,7 +1171,7 @@ void dm_bufio_prefetch(struct dm_bufio_client *c, 
			dm_bufio_unlock(c);



			if (need_submit)

				submit_io(b, READ, b->block, read_endio);

				submit_io(b, READ, read_endio);

			dm_bufio_release(b);



			cond_resched();
@@ -1405,7 +1412,7 @@ void dm_bufio_release_move(struct dm_buffer *b, sector_t new_block) 
		old_block = b->block;

		__unlink_buffer(b);

		__link_buffer(b, new_block, b->list_mode);

		submit_io(b, WRITE, new_block, write_endio);

		submit_io(b, WRITE, write_endio);

		wait_on_bit_io(&b->state, B_WRITING,

			       TASK_UNINTERRUPTIBLE);

		__unlink_buffer(b);
@@ -1762,6 +1769,12 @@ void dm_bufio_client_destroy(struct dm_bufio_client *c) 
}

EXPORT_SYMBOL_GPL(dm_bufio_client_destroy);



void dm_bufio_set_sector_offset(struct dm_bufio_client *c, sector_t start)

{

	c->start = start;

}

EXPORT_SYMBOL_GPL(dm_bufio_set_sector_offset);



static unsigned get_max_age_hz(void)

{

	unsigned max_age = ACCESS_ONCE(dm_bufio_max_age);

drivers/md/dm-bufio.h

+7 −0
Original line number Diff line number Diff line
@@ -31,6 +31,13 @@ dm_bufio_client_create(struct block_device *bdev, unsigned block_size, 
 */

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:

 *