From 400a0befc96240f7bb2a53b9622deffd55d385fe Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 4 Jan 2017 20:23:52 +0100 Subject: [PATCH] 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: Mikulas Patocka Signed-off-by: Milan Broz Signed-off-by: Mike Snitzer --- drivers/md/dm-bufio.c | 51 ++++++++++++++++++++++++++++++++------------------- drivers/md/dm-bufio.h | 7 +++++++ 2 files changed, 39 insertions(+), 19 deletions(-) diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index df4859f..280b56c 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -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 @@ retry: 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); diff --git a/drivers/md/dm-bufio.h b/drivers/md/dm-bufio.h index c096779..b6d8f53 100644 --- a/drivers/md/dm-bufio.h +++ b/drivers/md/dm-bufio.h @@ -32,6 +32,13 @@ 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: * * - At most one thread can hold at most "reserved_buffers" simultaneously. -- 2.7.4