diff options
Diffstat (limited to 'fs/exofs/ore_raid.c')
| -rw-r--r-- | fs/exofs/ore_raid.c | 721 |
1 files changed, 721 insertions, 0 deletions
diff --git a/fs/exofs/ore_raid.c b/fs/exofs/ore_raid.c new file mode 100644 index 000000000..27cbdb697 --- /dev/null +++ b/fs/exofs/ore_raid.c @@ -0,0 +1,721 @@ +/* + * Copyright (C) 2011 + * Boaz Harrosh <ooo@electrozaur.com> + * + * This file is part of the objects raid engine (ore). + * + * It is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + * You should have received a copy of the GNU General Public License + * along with "ore". If not, write to the Free Software Foundation, Inc: + * "Free Software Foundation <info@fsf.org>" + */ + +#include <linux/gfp.h> +#include <linux/async_tx.h> + +#include "ore_raid.h" + +#undef ORE_DBGMSG2 +#define ORE_DBGMSG2 ORE_DBGMSG + +static struct page *_raid_page_alloc(void) +{ + return alloc_page(GFP_KERNEL); +} + +static void _raid_page_free(struct page *p) +{ + __free_page(p); +} + +/* This struct is forward declare in ore_io_state, but is private to here. + * It is put on ios->sp2d for RAID5/6 writes only. See _gen_xor_unit. + * + * __stripe_pages_2d is a 2d array of pages, and it is also a corner turn. + * Ascending page index access is sp2d(p-minor, c-major). But storage is + * sp2d[p-minor][c-major], so it can be properlly presented to the async-xor + * API. + */ +struct __stripe_pages_2d { + /* Cache some hot path repeated calculations */ + unsigned parity; + unsigned data_devs; + unsigned pages_in_unit; + + bool needed ; + + /* Array size is pages_in_unit (layout->stripe_unit / PAGE_SIZE) */ + struct __1_page_stripe { + bool alloc; + unsigned write_count; + struct async_submit_ctl submit; + struct dma_async_tx_descriptor *tx; + + /* The size of this array is data_devs + parity */ + struct page **pages; + struct page **scribble; + /* bool array, size of this array is data_devs */ + char *page_is_read; + } _1p_stripes[]; +}; + +/* This can get bigger then a page. So support multiple page allocations + * _sp2d_free should be called even if _sp2d_alloc fails (by returning + * none-zero). + */ +static int _sp2d_alloc(unsigned pages_in_unit, unsigned group_width, + unsigned parity, struct __stripe_pages_2d **psp2d) +{ + struct __stripe_pages_2d *sp2d; + unsigned data_devs = group_width - parity; + struct _alloc_all_bytes { + struct __alloc_stripe_pages_2d { + struct __stripe_pages_2d sp2d; + struct __1_page_stripe _1p_stripes[pages_in_unit]; + } __asp2d; + struct __alloc_1p_arrays { + struct page *pages[group_width]; + struct page *scribble[group_width]; + char page_is_read[data_devs]; + } __a1pa[pages_in_unit]; + } *_aab; + struct __alloc_1p_arrays *__a1pa; + struct __alloc_1p_arrays *__a1pa_end; + const unsigned sizeof__a1pa = sizeof(_aab->__a1pa[0]); + unsigned num_a1pa, alloc_size, i; + + /* FIXME: check these numbers in ore_verify_layout */ + BUG_ON(sizeof(_aab->__asp2d) > PAGE_SIZE); + BUG_ON(sizeof__a1pa > PAGE_SIZE); + + if (sizeof(*_aab) > PAGE_SIZE) { + num_a1pa = (PAGE_SIZE - sizeof(_aab->__asp2d)) / sizeof__a1pa; + alloc_size = sizeof(_aab->__asp2d) + sizeof__a1pa * num_a1pa; + } else { + num_a1pa = pages_in_unit; + alloc_size = sizeof(*_aab); + } + + _aab = kzalloc(alloc_size, GFP_KERNEL); + if (unlikely(!_aab)) { + ORE_DBGMSG("!! Failed to alloc sp2d size=%d\n", alloc_size); + return -ENOMEM; + } + + sp2d = &_aab->__asp2d.sp2d; + *psp2d = sp2d; /* From here Just call _sp2d_free */ + + __a1pa = _aab->__a1pa; + __a1pa_end = __a1pa + num_a1pa; + + for (i = 0; i < pages_in_unit; ++i) { + if (unlikely(__a1pa >= __a1pa_end)) { + num_a1pa = min_t(unsigned, PAGE_SIZE / sizeof__a1pa, + pages_in_unit - i); + + __a1pa = kcalloc(num_a1pa, sizeof__a1pa, GFP_KERNEL); + if (unlikely(!__a1pa)) { + ORE_DBGMSG("!! Failed to _alloc_1p_arrays=%d\n", + num_a1pa); + return -ENOMEM; + } + __a1pa_end = __a1pa + num_a1pa; + /* First *pages is marked for kfree of the buffer */ + sp2d->_1p_stripes[i].alloc = true; + } + + sp2d->_1p_stripes[i].pages = __a1pa->pages; + sp2d->_1p_stripes[i].scribble = __a1pa->scribble ; + sp2d->_1p_stripes[i].page_is_read = __a1pa->page_is_read; + ++__a1pa; + } + + sp2d->parity = parity; + sp2d->data_devs = data_devs; + sp2d->pages_in_unit = pages_in_unit; + return 0; +} + +static void _sp2d_reset(struct __stripe_pages_2d *sp2d, + const struct _ore_r4w_op *r4w, void *priv) +{ + unsigned data_devs = sp2d->data_devs; + unsigned group_width = data_devs + sp2d->parity; + int p, c; + + if (!sp2d->needed) + return; + + for (c = data_devs - 1; c >= 0; --c) + for (p = sp2d->pages_in_unit - 1; p >= 0; --p) { + struct __1_page_stripe *_1ps = &sp2d->_1p_stripes[p]; + + if (_1ps->page_is_read[c]) { + struct page *page = _1ps->pages[c]; + + r4w->put_page(priv, page); + _1ps->page_is_read[c] = false; + } + } + + for (p = 0; p < sp2d->pages_in_unit; p++) { + struct __1_page_stripe *_1ps = &sp2d->_1p_stripes[p]; + + memset(_1ps->pages, 0, group_width * sizeof(*_1ps->pages)); + _1ps->write_count = 0; + _1ps->tx = NULL; + } + + sp2d->needed = false; +} + +static void _sp2d_free(struct __stripe_pages_2d *sp2d) +{ + unsigned i; + + if (!sp2d) + return; + + for (i = 0; i < sp2d->pages_in_unit; ++i) { + if (sp2d->_1p_stripes[i].alloc) + kfree(sp2d->_1p_stripes[i].pages); + } + + kfree(sp2d); +} + +static unsigned _sp2d_min_pg(struct __stripe_pages_2d *sp2d) +{ + unsigned p; + + for (p = 0; p < sp2d->pages_in_unit; p++) { + struct __1_page_stripe *_1ps = &sp2d->_1p_stripes[p]; + + if (_1ps->write_count) + return p; + } + + return ~0; +} + +static unsigned _sp2d_max_pg(struct __stripe_pages_2d *sp2d) +{ + int p; + + for (p = sp2d->pages_in_unit - 1; p >= 0; --p) { + struct __1_page_stripe *_1ps = &sp2d->_1p_stripes[p]; + + if (_1ps->write_count) + return p; + } + + return ~0; +} + +static void _gen_xor_unit(struct __stripe_pages_2d *sp2d) +{ + unsigned p; + unsigned tx_flags = ASYNC_TX_ACK; + + if (sp2d->parity == 1) + tx_flags |= ASYNC_TX_XOR_ZERO_DST; + + for (p = 0; p < sp2d->pages_in_unit; p++) { + struct __1_page_stripe *_1ps = &sp2d->_1p_stripes[p]; + + if (!_1ps->write_count) + continue; + + init_async_submit(&_1ps->submit, tx_flags, + NULL, NULL, NULL, (addr_conv_t *)_1ps->scribble); + + if (sp2d->parity == 1) + _1ps->tx = async_xor(_1ps->pages[sp2d->data_devs], + _1ps->pages, 0, sp2d->data_devs, + PAGE_SIZE, &_1ps->submit); + else /* parity == 2 */ + _1ps->tx = async_gen_syndrome(_1ps->pages, 0, + sp2d->data_devs + sp2d->parity, + PAGE_SIZE, &_1ps->submit); + } + + for (p = 0; p < sp2d->pages_in_unit; p++) { + struct __1_page_stripe *_1ps = &sp2d->_1p_stripes[p]; + /* NOTE: We wait for HW synchronously (I don't have such HW + * to test with.) Is parallelism needed with today's multi + * cores? + */ + async_tx_issue_pending(_1ps->tx); + } +} + +void _ore_add_stripe_page(struct __stripe_pages_2d *sp2d, + struct ore_striping_info *si, struct page *page) +{ + struct __1_page_stripe *_1ps; + + sp2d->needed = true; + + _1ps = &sp2d->_1p_stripes[si->cur_pg]; + _1ps->pages[si->cur_comp] = page; + ++_1ps->write_count; + + si->cur_pg = (si->cur_pg + 1) % sp2d->pages_in_unit; + /* si->cur_comp is advanced outside at main loop */ +} + +void _ore_add_sg_seg(struct ore_per_dev_state *per_dev, unsigned cur_len, + bool not_last) +{ + struct osd_sg_entry *sge; + + ORE_DBGMSG("dev=%d cur_len=0x%x not_last=%d cur_sg=%d " + "offset=0x%llx length=0x%x last_sgs_total=0x%x\n", + per_dev->dev, cur_len, not_last, per_dev->cur_sg, + _LLU(per_dev->offset), per_dev->length, + per_dev->last_sgs_total); + + if (!per_dev->cur_sg) { + sge = per_dev->sglist; + + /* First time we prepare two entries */ + if (per_dev->length) { + ++per_dev->cur_sg; + sge->offset = per_dev->offset; + sge->len = per_dev->length; + } else { + /* Here the parity is the first unit of this object. + * This happens every time we reach a parity device on + * the same stripe as the per_dev->offset. We need to + * just skip this unit. + */ + per_dev->offset += cur_len; + return; + } + } else { + /* finalize the last one */ + sge = &per_dev->sglist[per_dev->cur_sg - 1]; + sge->len = per_dev->length - per_dev->last_sgs_total; + } + + if (not_last) { + /* Partly prepare the next one */ + struct osd_sg_entry *next_sge = sge + 1; + + ++per_dev->cur_sg; + next_sge->offset = sge->offset + sge->len + cur_len; + /* Save cur len so we know how mutch was added next time */ + per_dev->last_sgs_total = per_dev->length; + next_sge->len = 0; + } else if (!sge->len) { + /* Optimize for when the last unit is a parity */ + --per_dev->cur_sg; + } +} + +static int _alloc_read_4_write(struct ore_io_state *ios) +{ + struct ore_layout *layout = ios->layout; + int ret; + /* We want to only read those pages not in cache so worst case + * is a stripe populated with every other page + */ + unsigned sgs_per_dev = ios->sp2d->pages_in_unit + 2; + + ret = _ore_get_io_state(layout, ios->oc, + layout->group_width * layout->mirrors_p1, + sgs_per_dev, 0, &ios->ios_read_4_write); + return ret; +} + +/* @si contains info of the to-be-inserted page. Update of @si should be + * maintained by caller. Specificaly si->dev, si->obj_offset, ... + */ +static int _add_to_r4w(struct ore_io_state *ios, struct ore_striping_info *si, + struct page *page, unsigned pg_len) +{ + struct request_queue *q; + struct ore_per_dev_state *per_dev; + struct ore_io_state *read_ios; + unsigned first_dev = si->dev - (si->dev % + (ios->layout->group_width * ios->layout->mirrors_p1)); + unsigned comp = si->dev - first_dev; + unsigned added_len; + + if (!ios->ios_read_4_write) { + int ret = _alloc_read_4_write(ios); + + if (unlikely(ret)) + return ret; + } + + read_ios = ios->ios_read_4_write; + read_ios->numdevs = ios->layout->group_width * ios->layout->mirrors_p1; + + per_dev = &read_ios->per_dev[comp]; + if (!per_dev->length) { + per_dev->bio = bio_kmalloc(GFP_KERNEL, + ios->sp2d->pages_in_unit); + if (unlikely(!per_dev->bio)) { + ORE_DBGMSG("Failed to allocate BIO size=%u\n", + ios->sp2d->pages_in_unit); + return -ENOMEM; + } + per_dev->offset = si->obj_offset; + per_dev->dev = si->dev; + } else if (si->obj_offset != (per_dev->offset + per_dev->length)) { + u64 gap = si->obj_offset - (per_dev->offset + per_dev->length); + + _ore_add_sg_seg(per_dev, gap, true); + } + q = osd_request_queue(ore_comp_dev(read_ios->oc, per_dev->dev)); + added_len = bio_add_pc_page(q, per_dev->bio, page, pg_len, + si->obj_offset % PAGE_SIZE); + if (unlikely(added_len != pg_len)) { + ORE_DBGMSG("Failed to bio_add_pc_page bi_vcnt=%d\n", + per_dev->bio->bi_vcnt); + return -ENOMEM; + } + + per_dev->length += pg_len; + return 0; +} + +/* read the beginning of an unaligned first page */ +static int _add_to_r4w_first_page(struct ore_io_state *ios, struct page *page) +{ + struct ore_striping_info si; + unsigned pg_len; + + ore_calc_stripe_info(ios->layout, ios->offset, 0, &si); + + pg_len = si.obj_offset % PAGE_SIZE; + si.obj_offset -= pg_len; + + ORE_DBGMSG("offset=0x%llx len=0x%x index=0x%lx dev=%x\n", + _LLU(si.obj_offset), pg_len, page->index, si.dev); + + return _add_to_r4w(ios, &si, page, pg_len); +} + +/* read the end of an incomplete last page */ +static int _add_to_r4w_last_page(struct ore_io_state *ios, u64 *offset) +{ + struct ore_striping_info si; + struct page *page; + unsigned pg_len, p, c; + + ore_calc_stripe_info(ios->layout, *offset, 0, &si); + + p = si.cur_pg; + c = si.cur_comp; + page = ios->sp2d->_1p_stripes[p].pages[c]; + + pg_len = PAGE_SIZE - (si.unit_off % PAGE_SIZE); + *offset += pg_len; + + ORE_DBGMSG("p=%d, c=%d next-offset=0x%llx len=0x%x dev=%x par_dev=%d\n", + p, c, _LLU(*offset), pg_len, si.dev, si.par_dev); + + BUG_ON(!page); + + return _add_to_r4w(ios, &si, page, pg_len); +} + +static void _mark_read4write_pages_uptodate(struct ore_io_state *ios, int ret) +{ + struct bio_vec *bv; + unsigned i, d; + + /* loop on all devices all pages */ + for (d = 0; d < ios->numdevs; d++) { + struct bio *bio = ios->per_dev[d].bio; + + if (!bio) + continue; + + bio_for_each_segment_all(bv, bio, i) { + struct page *page = bv->bv_page; + + SetPageUptodate(page); + if (PageError(page)) + ClearPageError(page); + } + } +} + +/* read_4_write is hacked to read the start of the first stripe and/or + * the end of the last stripe. If needed, with an sg-gap at each device/page. + * It is assumed to be called after the to_be_written pages of the first stripe + * are populating ios->sp2d[][] + * + * NOTE: We call ios->r4w->lock_fn for all pages needed for parity calculations + * These pages are held at sp2d[p].pages[c] but with + * sp2d[p].page_is_read[c] = true. At _sp2d_reset these pages are + * ios->r4w->lock_fn(). The ios->r4w->lock_fn might signal that the page is + * @uptodate=true, so we don't need to read it, only unlock, after IO. + * + * TODO: The read_4_write should calc a need_to_read_pages_count, if bigger then + * to-be-written count, we should consider the xor-in-place mode. + * need_to_read_pages_count is the actual number of pages not present in cache. + * maybe "devs_in_group - ios->sp2d[p].write_count" is a good enough + * approximation? In this mode the read pages are put in the empty places of + * ios->sp2d[p][*], xor is calculated the same way. These pages are + * allocated/freed and don't go through cache + */ +static int _read_4_write_first_stripe(struct ore_io_state *ios) +{ + struct ore_striping_info read_si; + struct __stripe_pages_2d *sp2d = ios->sp2d; + u64 offset = ios->si.first_stripe_start; + unsigned c, p, min_p = sp2d->pages_in_unit, max_p = -1; + + if (offset == ios->offset) /* Go to start collect $200 */ + goto read_last_stripe; + + min_p = _sp2d_min_pg(sp2d); + max_p = _sp2d_max_pg(sp2d); + + ORE_DBGMSG("stripe_start=0x%llx ios->offset=0x%llx min_p=%d max_p=%d\n", + offset, ios->offset, min_p, max_p); + + for (c = 0; ; c++) { + ore_calc_stripe_info(ios->layout, offset, 0, &read_si); + read_si.obj_offset += min_p * PAGE_SIZE; + offset += min_p * PAGE_SIZE; + for (p = min_p; p <= max_p; p++) { + struct __1_page_stripe *_1ps = &sp2d->_1p_stripes[p]; + struct page **pp = &_1ps->pages[c]; + bool uptodate; + + if (*pp) { + if (ios->offset % PAGE_SIZE) + /* Read the remainder of the page */ + _add_to_r4w_first_page(ios, *pp); + /* to-be-written pages start here */ + goto read_last_stripe; + } + + *pp = ios->r4w->get_page(ios->private, offset, + &uptodate); + if (unlikely(!*pp)) + return -ENOMEM; + + if (!uptodate) + _add_to_r4w(ios, &read_si, *pp, PAGE_SIZE); + + /* Mark read-pages to be cache_released */ + _1ps->page_is_read[c] = true; + read_si.obj_offset += PAGE_SIZE; + offset += PAGE_SIZE; + } + offset += (sp2d->pages_in_unit - p) * PAGE_SIZE; + } + +read_last_stripe: + return 0; +} + +static int _read_4_write_last_stripe(struct ore_io_state *ios) +{ + struct ore_striping_info read_si; + struct __stripe_pages_2d *sp2d = ios->sp2d; + u64 offset; + u64 last_stripe_end; + unsigned bytes_in_stripe = ios->si.bytes_in_stripe; + unsigned c, p, min_p = sp2d->pages_in_unit, max_p = -1; + + offset = ios->offset + ios->length; + if (offset % PAGE_SIZE) + _add_to_r4w_last_page(ios, &offset); + /* offset will be aligned to next page */ + + last_stripe_end = div_u64(offset + bytes_in_stripe - 1, bytes_in_stripe) + * bytes_in_stripe; + if (offset == last_stripe_end) /* Optimize for the aligned case */ + goto read_it; + + ore_calc_stripe_info(ios->layout, offset, 0, &read_si); + p = read_si.cur_pg; + c = read_si.cur_comp; + + if (min_p == sp2d->pages_in_unit) { + /* Didn't do it yet */ + min_p = _sp2d_min_pg(sp2d); + max_p = _sp2d_max_pg(sp2d); + } + + ORE_DBGMSG("offset=0x%llx stripe_end=0x%llx min_p=%d max_p=%d\n", + offset, last_stripe_end, min_p, max_p); + + while (offset < last_stripe_end) { + struct __1_page_stripe *_1ps = &sp2d->_1p_stripes[p]; + + if ((min_p <= p) && (p <= max_p)) { + struct page *page; + bool uptodate; + + BUG_ON(_1ps->pages[c]); + page = ios->r4w->get_page(ios->private, offset, + &uptodate); + if (unlikely(!page)) + return -ENOMEM; + + _1ps->pages[c] = page; + /* Mark read-pages to be cache_released */ + _1ps->page_is_read[c] = true; + if (!uptodate) + _add_to_r4w(ios, &read_si, page, PAGE_SIZE); + } + + offset += PAGE_SIZE; + if (p == (sp2d->pages_in_unit - 1)) { + ++c; + p = 0; + ore_calc_stripe_info(ios->layout, offset, 0, &read_si); + } else { + read_si.obj_offset += PAGE_SIZE; + ++p; + } + } + +read_it: + return 0; +} + +static int _read_4_write_execute(struct ore_io_state *ios) +{ + struct ore_io_state *ios_read; + unsigned i; + int ret; + + ios_read = ios->ios_read_4_write; + if (!ios_read) + return 0; + + /* FIXME: Ugly to signal _sbi_read_mirror that we have bio(s). Change + * to check for per_dev->bio + */ + ios_read->pages = ios->pages; + + /* Now read these devices */ + for (i = 0; i < ios_read->numdevs; i += ios_read->layout->mirrors_p1) { + ret = _ore_read_mirror(ios_read, i); + if (unlikely(ret)) + return ret; + } + + ret = ore_io_execute(ios_read); /* Synchronus execution */ + if (unlikely(ret)) { + ORE_DBGMSG("!! ore_io_execute => %d\n", ret); + return ret; + } + + _mark_read4write_pages_uptodate(ios_read, ret); + ore_put_io_state(ios_read); + ios->ios_read_4_write = NULL; /* Might need a reuse at last stripe */ + return 0; +} + +/* In writes @cur_len means length left. .i.e cur_len==0 is the last parity U */ +int _ore_add_parity_unit(struct ore_io_state *ios, + struct ore_striping_info *si, + struct ore_per_dev_state *per_dev, + unsigned cur_len, bool do_xor) +{ + if (ios->reading) { + if (per_dev->cur_sg >= ios->sgs_per_dev) { + ORE_DBGMSG("cur_sg(%d) >= sgs_per_dev(%d)\n" , + per_dev->cur_sg, ios->sgs_per_dev); + return -ENOMEM; + } + _ore_add_sg_seg(per_dev, cur_len, true); + } else { + struct __stripe_pages_2d *sp2d = ios->sp2d; + struct page **pages = ios->parity_pages + ios->cur_par_page; + unsigned num_pages; + unsigned array_start = 0; + unsigned i; + int ret; + + si->cur_pg = _sp2d_min_pg(sp2d); + num_pages = _sp2d_max_pg(sp2d) + 1 - si->cur_pg; + + if (!per_dev->length) { + per_dev->offset += si->cur_pg * PAGE_SIZE; + /* If first stripe, Read in all read4write pages + * (if needed) before we calculate the first parity. + */ + if (do_xor) + _read_4_write_first_stripe(ios); + } + if (!cur_len && do_xor) + /* If last stripe r4w pages of last stripe */ + _read_4_write_last_stripe(ios); + _read_4_write_execute(ios); + + for (i = 0; i < num_pages; i++) { + pages[i] = _raid_page_alloc(); + if (unlikely(!pages[i])) + return -ENOMEM; + + ++(ios->cur_par_page); + } + + BUG_ON(si->cur_comp < sp2d->data_devs); + BUG_ON(si->cur_pg + num_pages > sp2d->pages_in_unit); + + ret = _ore_add_stripe_unit(ios, &array_start, 0, pages, + per_dev, num_pages * PAGE_SIZE); + if (unlikely(ret)) + return ret; + + if (do_xor) { + _gen_xor_unit(sp2d); + _sp2d_reset(sp2d, ios->r4w, ios->private); + } + } + return 0; +} + +int _ore_post_alloc_raid_stuff(struct ore_io_state *ios) +{ + if (ios->parity_pages) { + struct ore_layout *layout = ios->layout; + unsigned pages_in_unit = layout->stripe_unit / PAGE_SIZE; + + if (_sp2d_alloc(pages_in_unit, layout->group_width, + layout->parity, &ios->sp2d)) { + return -ENOMEM; + } + } + return 0; +} + +void _ore_free_raid_stuff(struct ore_io_state *ios) +{ + if (ios->sp2d) { /* writing and raid */ + unsigned i; + + for (i = 0; i < ios->cur_par_page; i++) { + struct page *page = ios->parity_pages[i]; + + if (page) + _raid_page_free(page); + } + if (ios->extra_part_alloc) + kfree(ios->parity_pages); + /* If IO returned an error pages might need unlocking */ + _sp2d_reset(ios->sp2d, ios->r4w, ios->private); + _sp2d_free(ios->sp2d); + } else { + /* Will only be set if raid reading && sglist is big */ + if (ios->extra_part_alloc) + kfree(ios->per_dev[0].sglist); + } + if (ios->ios_read_4_write) + ore_put_io_state(ios->ios_read_4_write); +} |