Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Alasdair G. Kergon | 1017 | 39.90% | 4 | 7.84% |
Heinz Mauelshagen | 509 | 19.97% | 5 | 9.80% |
Mikulas Patocka | 338 | 13.26% | 7 | 13.73% |
Joe Thornber | 158 | 6.20% | 2 | 3.92% |
Mike Snitzer | 97 | 3.81% | 4 | 7.84% |
Michael Christie | 82 | 3.22% | 4 | 7.84% |
Milan Broz | 64 | 2.51% | 2 | 3.92% |
Lei Ming | 60 | 2.35% | 1 | 1.96% |
Christoph Hellwig | 53 | 2.08% | 6 | 11.76% |
Darrick J. Wong | 53 | 2.08% | 2 | 3.92% |
Kent Overstreet | 47 | 1.84% | 5 | 9.80% |
Kevin Corry | 41 | 1.61% | 1 | 1.96% |
Jun'ichi Nomura | 9 | 0.35% | 1 | 1.96% |
Sasha Levin | 8 | 0.31% | 1 | 1.96% |
Al Viro | 6 | 0.24% | 1 | 1.96% |
Neil Brown | 3 | 0.12% | 2 | 3.92% |
Jens Axboe | 2 | 0.08% | 2 | 3.92% |
Dave Olien | 2 | 0.08% | 1 | 1.96% |
Total | 2549 | 51 |
/* * Copyright (C) 2003 Sistina Software * Copyright (C) 2006 Red Hat GmbH * * This file is released under the GPL. */ #include "dm-core.h" #include <linux/device-mapper.h> #include <linux/bio.h> #include <linux/completion.h> #include <linux/mempool.h> #include <linux/module.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/dm-io.h> #define DM_MSG_PREFIX "io" #define DM_IO_MAX_REGIONS BITS_PER_LONG struct dm_io_client { mempool_t pool; struct bio_set bios; }; /* * Aligning 'struct io' reduces the number of bits required to store * its address. Refer to store_io_and_region_in_bio() below. */ struct io { unsigned long error_bits; atomic_t count; struct dm_io_client *client; io_notify_fn callback; void *context; void *vma_invalidate_address; unsigned long vma_invalidate_size; } __attribute__((aligned(DM_IO_MAX_REGIONS))); static struct kmem_cache *_dm_io_cache; /* * Create a client with mempool and bioset. */ struct dm_io_client *dm_io_client_create(void) { struct dm_io_client *client; unsigned min_ios = dm_get_reserved_bio_based_ios(); int ret; client = kzalloc(sizeof(*client), GFP_KERNEL); if (!client) return ERR_PTR(-ENOMEM); ret = mempool_init_slab_pool(&client->pool, min_ios, _dm_io_cache); if (ret) goto bad; ret = bioset_init(&client->bios, min_ios, 0, BIOSET_NEED_BVECS); if (ret) goto bad; return client; bad: mempool_exit(&client->pool); kfree(client); return ERR_PTR(ret); } EXPORT_SYMBOL(dm_io_client_create); void dm_io_client_destroy(struct dm_io_client *client) { mempool_exit(&client->pool); bioset_exit(&client->bios); kfree(client); } EXPORT_SYMBOL(dm_io_client_destroy); /*----------------------------------------------------------------- * We need to keep track of which region a bio is doing io for. * To avoid a memory allocation to store just 5 or 6 bits, we * ensure the 'struct io' pointer is aligned so enough low bits are * always zero and then combine it with the region number directly in * bi_private. *---------------------------------------------------------------*/ static void store_io_and_region_in_bio(struct bio *bio, struct io *io, unsigned region) { if (unlikely(!IS_ALIGNED((unsigned long)io, DM_IO_MAX_REGIONS))) { DMCRIT("Unaligned struct io pointer %p", io); BUG(); } bio->bi_private = (void *)((unsigned long)io | region); } static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io, unsigned *region) { unsigned long val = (unsigned long)bio->bi_private; *io = (void *)(val & -(unsigned long)DM_IO_MAX_REGIONS); *region = val & (DM_IO_MAX_REGIONS - 1); } /*----------------------------------------------------------------- * We need an io object to keep track of the number of bios that * have been dispatched for a particular io. *---------------------------------------------------------------*/ static void complete_io(struct io *io) { unsigned long error_bits = io->error_bits; io_notify_fn fn = io->callback; void *context = io->context; if (io->vma_invalidate_size) invalidate_kernel_vmap_range(io->vma_invalidate_address, io->vma_invalidate_size); mempool_free(io, &io->client->pool); fn(error_bits, context); } static void dec_count(struct io *io, unsigned int region, blk_status_t error) { if (error) set_bit(region, &io->error_bits); if (atomic_dec_and_test(&io->count)) complete_io(io); } static void endio(struct bio *bio) { struct io *io; unsigned region; blk_status_t error; if (bio->bi_status && bio_data_dir(bio) == READ) zero_fill_bio(bio); /* * The bio destructor in bio_put() may use the io object. */ retrieve_io_and_region_from_bio(bio, &io, ®ion); error = bio->bi_status; bio_put(bio); dec_count(io, region, error); } /*----------------------------------------------------------------- * These little objects provide an abstraction for getting a new * destination page for io. *---------------------------------------------------------------*/ struct dpages { void (*get_page)(struct dpages *dp, struct page **p, unsigned long *len, unsigned *offset); void (*next_page)(struct dpages *dp); union { unsigned context_u; struct bvec_iter context_bi; }; void *context_ptr; void *vma_invalidate_address; unsigned long vma_invalidate_size; }; /* * Functions for getting the pages from a list. */ static void list_get_page(struct dpages *dp, struct page **p, unsigned long *len, unsigned *offset) { unsigned o = dp->context_u; struct page_list *pl = (struct page_list *) dp->context_ptr; *p = pl->page; *len = PAGE_SIZE - o; *offset = o; } static void list_next_page(struct dpages *dp) { struct page_list *pl = (struct page_list *) dp->context_ptr; dp->context_ptr = pl->next; dp->context_u = 0; } static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned offset) { dp->get_page = list_get_page; dp->next_page = list_next_page; dp->context_u = offset; dp->context_ptr = pl; } /* * Functions for getting the pages from a bvec. */ static void bio_get_page(struct dpages *dp, struct page **p, unsigned long *len, unsigned *offset) { struct bio_vec bvec = bvec_iter_bvec((struct bio_vec *)dp->context_ptr, dp->context_bi); *p = bvec.bv_page; *len = bvec.bv_len; *offset = bvec.bv_offset; /* avoid figuring it out again in bio_next_page() */ dp->context_bi.bi_sector = (sector_t)bvec.bv_len; } static void bio_next_page(struct dpages *dp) { unsigned int len = (unsigned int)dp->context_bi.bi_sector; bvec_iter_advance((struct bio_vec *)dp->context_ptr, &dp->context_bi, len); } static void bio_dp_init(struct dpages *dp, struct bio *bio) { dp->get_page = bio_get_page; dp->next_page = bio_next_page; /* * We just use bvec iterator to retrieve pages, so it is ok to * access the bvec table directly here */ dp->context_ptr = bio->bi_io_vec; dp->context_bi = bio->bi_iter; } /* * Functions for getting the pages from a VMA. */ static void vm_get_page(struct dpages *dp, struct page **p, unsigned long *len, unsigned *offset) { *p = vmalloc_to_page(dp->context_ptr); *offset = dp->context_u; *len = PAGE_SIZE - dp->context_u; } static void vm_next_page(struct dpages *dp) { dp->context_ptr += PAGE_SIZE - dp->context_u; dp->context_u = 0; } static void vm_dp_init(struct dpages *dp, void *data) { dp->get_page = vm_get_page; dp->next_page = vm_next_page; dp->context_u = offset_in_page(data); dp->context_ptr = data; } /* * Functions for getting the pages from kernel memory. */ static void km_get_page(struct dpages *dp, struct page **p, unsigned long *len, unsigned *offset) { *p = virt_to_page(dp->context_ptr); *offset = dp->context_u; *len = PAGE_SIZE - dp->context_u; } static void km_next_page(struct dpages *dp) { dp->context_ptr += PAGE_SIZE - dp->context_u; dp->context_u = 0; } static void km_dp_init(struct dpages *dp, void *data) { dp->get_page = km_get_page; dp->next_page = km_next_page; dp->context_u = offset_in_page(data); dp->context_ptr = data; } /*----------------------------------------------------------------- * IO routines that accept a list of pages. *---------------------------------------------------------------*/ static void do_region(int op, int op_flags, unsigned region, struct dm_io_region *where, struct dpages *dp, struct io *io) { struct bio *bio; struct page *page; unsigned long len; unsigned offset; unsigned num_bvecs; sector_t remaining = where->count; struct request_queue *q = bdev_get_queue(where->bdev); unsigned short logical_block_size = queue_logical_block_size(q); sector_t num_sectors; unsigned int uninitialized_var(special_cmd_max_sectors); /* * Reject unsupported discard and write same requests. */ if (op == REQ_OP_DISCARD) special_cmd_max_sectors = q->limits.max_discard_sectors; else if (op == REQ_OP_WRITE_ZEROES) special_cmd_max_sectors = q->limits.max_write_zeroes_sectors; else if (op == REQ_OP_WRITE_SAME) special_cmd_max_sectors = q->limits.max_write_same_sectors; if ((op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES || op == REQ_OP_WRITE_SAME) && special_cmd_max_sectors == 0) { atomic_inc(&io->count); dec_count(io, region, BLK_STS_NOTSUPP); return; } /* * where->count may be zero if op holds a flush and we need to * send a zero-sized flush. */ do { /* * Allocate a suitably sized-bio. */ switch (op) { case REQ_OP_DISCARD: case REQ_OP_WRITE_ZEROES: num_bvecs = 0; break; case REQ_OP_WRITE_SAME: num_bvecs = 1; break; default: num_bvecs = min_t(int, BIO_MAX_PAGES, dm_sector_div_up(remaining, (PAGE_SIZE >> SECTOR_SHIFT))); } bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, &io->client->bios); bio->bi_iter.bi_sector = where->sector + (where->count - remaining); bio_set_dev(bio, where->bdev); bio->bi_end_io = endio; bio_set_op_attrs(bio, op, op_flags); store_io_and_region_in_bio(bio, io, region); if (op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES) { num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining); bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT; remaining -= num_sectors; } else if (op == REQ_OP_WRITE_SAME) { /* * WRITE SAME only uses a single page. */ dp->get_page(dp, &page, &len, &offset); bio_add_page(bio, page, logical_block_size, offset); num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining); bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT; offset = 0; remaining -= num_sectors; dp->next_page(dp); } else while (remaining) { /* * Try and add as many pages as possible. */ dp->get_page(dp, &page, &len, &offset); len = min(len, to_bytes(remaining)); if (!bio_add_page(bio, page, len, offset)) break; offset = 0; remaining -= to_sector(len); dp->next_page(dp); } atomic_inc(&io->count); submit_bio(bio); } while (remaining); } static void dispatch_io(int op, int op_flags, unsigned int num_regions, struct dm_io_region *where, struct dpages *dp, struct io *io, int sync) { int i; struct dpages old_pages = *dp; BUG_ON(num_regions > DM_IO_MAX_REGIONS); if (sync) op_flags |= REQ_SYNC; /* * For multiple regions we need to be careful to rewind * the dp object for each call to do_region. */ for (i = 0; i < num_regions; i++) { *dp = old_pages; if (where[i].count || (op_flags & REQ_PREFLUSH)) do_region(op, op_flags, i, where + i, dp, io); } /* * Drop the extra reference that we were holding to avoid * the io being completed too early. */ dec_count(io, 0, 0); } struct sync_io { unsigned long error_bits; struct completion wait; }; static void sync_io_complete(unsigned long error, void *context) { struct sync_io *sio = context; sio->error_bits = error; complete(&sio->wait); } static int sync_io(struct dm_io_client *client, unsigned int num_regions, struct dm_io_region *where, int op, int op_flags, struct dpages *dp, unsigned long *error_bits) { struct io *io; struct sync_io sio; if (num_regions > 1 && !op_is_write(op)) { WARN_ON(1); return -EIO; } init_completion(&sio.wait); io = mempool_alloc(&client->pool, GFP_NOIO); io->error_bits = 0; atomic_set(&io->count, 1); /* see dispatch_io() */ io->client = client; io->callback = sync_io_complete; io->context = &sio; io->vma_invalidate_address = dp->vma_invalidate_address; io->vma_invalidate_size = dp->vma_invalidate_size; dispatch_io(op, op_flags, num_regions, where, dp, io, 1); wait_for_completion_io(&sio.wait); if (error_bits) *error_bits = sio.error_bits; return sio.error_bits ? -EIO : 0; } static int async_io(struct dm_io_client *client, unsigned int num_regions, struct dm_io_region *where, int op, int op_flags, struct dpages *dp, io_notify_fn fn, void *context) { struct io *io; if (num_regions > 1 && !op_is_write(op)) { WARN_ON(1); fn(1, context); return -EIO; } io = mempool_alloc(&client->pool, GFP_NOIO); io->error_bits = 0; atomic_set(&io->count, 1); /* see dispatch_io() */ io->client = client; io->callback = fn; io->context = context; io->vma_invalidate_address = dp->vma_invalidate_address; io->vma_invalidate_size = dp->vma_invalidate_size; dispatch_io(op, op_flags, num_regions, where, dp, io, 0); return 0; } static int dp_init(struct dm_io_request *io_req, struct dpages *dp, unsigned long size) { /* Set up dpages based on memory type */ dp->vma_invalidate_address = NULL; dp->vma_invalidate_size = 0; switch (io_req->mem.type) { case DM_IO_PAGE_LIST: list_dp_init(dp, io_req->mem.ptr.pl, io_req->mem.offset); break; case DM_IO_BIO: bio_dp_init(dp, io_req->mem.ptr.bio); break; case DM_IO_VMA: flush_kernel_vmap_range(io_req->mem.ptr.vma, size); if (io_req->bi_op == REQ_OP_READ) { dp->vma_invalidate_address = io_req->mem.ptr.vma; dp->vma_invalidate_size = size; } vm_dp_init(dp, io_req->mem.ptr.vma); break; case DM_IO_KMEM: km_dp_init(dp, io_req->mem.ptr.addr); break; default: return -EINVAL; } return 0; } /* * New collapsed (a)synchronous interface. * * If the IO is asynchronous (i.e. it has notify.fn), you must either unplug * the queue with blk_unplug() some time later or set REQ_SYNC in * io_req->bi_opf. If you fail to do one of these, the IO will be submitted to * the disk after q->unplug_delay, which defaults to 3ms in blk-settings.c. */ int dm_io(struct dm_io_request *io_req, unsigned num_regions, struct dm_io_region *where, unsigned long *sync_error_bits) { int r; struct dpages dp; r = dp_init(io_req, &dp, (unsigned long)where->count << SECTOR_SHIFT); if (r) return r; if (!io_req->notify.fn) return sync_io(io_req->client, num_regions, where, io_req->bi_op, io_req->bi_op_flags, &dp, sync_error_bits); return async_io(io_req->client, num_regions, where, io_req->bi_op, io_req->bi_op_flags, &dp, io_req->notify.fn, io_req->notify.context); } EXPORT_SYMBOL(dm_io); int __init dm_io_init(void) { _dm_io_cache = KMEM_CACHE(io, 0); if (!_dm_io_cache) return -ENOMEM; return 0; } void dm_io_exit(void) { kmem_cache_destroy(_dm_io_cache); _dm_io_cache = NULL; }
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