diff options
Diffstat (limited to 'fs/exofs')
| -rw-r--r-- | fs/exofs/Kbuild | 3 | ||||
| -rw-r--r-- | fs/exofs/ore.c | 326 | ||||
| -rw-r--r-- | fs/exofs/ore_raid.c | 140 | ||||
| -rw-r--r-- | fs/exofs/ore_raid.h | 64 |
4 files changed, 455 insertions, 78 deletions
diff --git a/fs/exofs/Kbuild b/fs/exofs/Kbuild index c5a5855a6c4..352ba149d23 100644 --- a/fs/exofs/Kbuild +++ b/fs/exofs/Kbuild @@ -13,7 +13,8 @@ # # ore module library -obj-$(CONFIG_ORE) += ore.o +libore-y := ore.o ore_raid.o +obj-$(CONFIG_ORE) += libore.o exofs-y := inode.o file.o symlink.o namei.o dir.o super.o obj-$(CONFIG_EXOFS_FS) += exofs.o diff --git a/fs/exofs/ore.c b/fs/exofs/ore.c index d92998d5c2d..fd6090ddd3b 100644 --- a/fs/exofs/ore.c +++ b/fs/exofs/ore.c @@ -24,24 +24,9 @@ #include <linux/slab.h> #include <asm/div64.h> +#include <linux/lcm.h> -#include <scsi/osd_ore.h> - -#define ORE_ERR(fmt, a...) printk(KERN_ERR "ore: " fmt, ##a) - -#ifdef CONFIG_EXOFS_DEBUG -#define ORE_DBGMSG(fmt, a...) \ - printk(KERN_NOTICE "ore @%s:%d: " fmt, __func__, __LINE__, ##a) -#else -#define ORE_DBGMSG(fmt, a...) \ - do { if (0) printk(fmt, ##a); } while (0) -#endif - -/* u64 has problems with printk this will cast it to unsigned long long */ -#define _LLU(x) (unsigned long long)(x) - -#define ORE_DBGMSG2(M...) do {} while (0) -/* #define ORE_DBGMSG2 ORE_DBGMSG */ +#include "ore_raid.h" MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>"); MODULE_DESCRIPTION("Objects Raid Engine ore.ko"); @@ -133,21 +118,81 @@ static struct osd_dev *_ios_od(struct ore_io_state *ios, unsigned index) return ore_comp_dev(ios->oc, index); } -static int _get_io_state(struct ore_layout *layout, - struct ore_components *oc, unsigned numdevs, - struct ore_io_state **pios) +static int _ore_get_io_state(struct ore_layout *layout, + struct ore_components *oc, unsigned numdevs, + unsigned sgs_per_dev, unsigned num_par_pages, + struct ore_io_state **pios) { struct ore_io_state *ios; + struct page **pages; + struct osd_sg_entry *sgilist; + struct __alloc_all_io_state { + struct ore_io_state ios; + struct ore_per_dev_state per_dev[numdevs]; + union { + struct osd_sg_entry sglist[sgs_per_dev * numdevs]; + struct page *pages[num_par_pages]; + }; + } *_aios; + + if (likely(sizeof(*_aios) <= PAGE_SIZE)) { + _aios = kzalloc(sizeof(*_aios), GFP_KERNEL); + if (unlikely(!_aios)) { + ORE_DBGMSG("Failed kzalloc bytes=%zd\n", + sizeof(*_aios)); + *pios = NULL; + return -ENOMEM; + } + pages = num_par_pages ? _aios->pages : NULL; + sgilist = sgs_per_dev ? _aios->sglist : NULL; + ios = &_aios->ios; + } else { + struct __alloc_small_io_state { + struct ore_io_state ios; + struct ore_per_dev_state per_dev[numdevs]; + } *_aio_small; + union __extra_part { + struct osd_sg_entry sglist[sgs_per_dev * numdevs]; + struct page *pages[num_par_pages]; + } *extra_part; + + _aio_small = kzalloc(sizeof(*_aio_small), GFP_KERNEL); + if (unlikely(!_aio_small)) { + ORE_DBGMSG("Failed alloc first part bytes=%zd\n", + sizeof(*_aio_small)); + *pios = NULL; + return -ENOMEM; + } + extra_part = kzalloc(sizeof(*extra_part), GFP_KERNEL); + if (unlikely(!extra_part)) { + ORE_DBGMSG("Failed alloc second part bytes=%zd\n", + sizeof(*extra_part)); + kfree(_aio_small); + *pios = NULL; + return -ENOMEM; + } - /*TODO: Maybe use kmem_cach per sbi of size - * exofs_io_state_size(layout->s_numdevs) - */ - ios = kzalloc(ore_io_state_size(numdevs), GFP_KERNEL); - if (unlikely(!ios)) { - ORE_DBGMSG("Failed kzalloc bytes=%d\n", - ore_io_state_size(numdevs)); - *pios = NULL; - return -ENOMEM; + pages = num_par_pages ? extra_part->pages : NULL; + sgilist = sgs_per_dev ? extra_part->sglist : NULL; + /* In this case the per_dev[0].sgilist holds the pointer to + * be freed + */ + ios = &_aio_small->ios; + ios->extra_part_alloc = true; + } + + if (pages) { + ios->parity_pages = pages; + ios->max_par_pages = num_par_pages; + } + if (sgilist) { + unsigned d; + + for (d = 0; d < numdevs; ++d) { + ios->per_dev[d].sglist = sgilist; + sgilist += sgs_per_dev; + } + ios->sgs_per_dev = sgs_per_dev; } ios->layout = layout; @@ -178,9 +223,42 @@ int ore_get_rw_state(struct ore_layout *layout, struct ore_components *oc, { struct ore_io_state *ios; unsigned numdevs = layout->group_width * layout->mirrors_p1; + unsigned sgs_per_dev = 0, max_par_pages = 0; int ret; - ret = _get_io_state(layout, oc, numdevs, pios); + if (layout->parity && length) { + unsigned data_devs = layout->group_width - layout->parity; + unsigned stripe_size = layout->stripe_unit * data_devs; + unsigned pages_in_unit = layout->stripe_unit / PAGE_SIZE; + u32 remainder; + u64 num_stripes; + u64 num_raid_units; + + num_stripes = div_u64_rem(length, stripe_size, &remainder); + if (remainder) + ++num_stripes; + + num_raid_units = num_stripes * layout->parity; + + if (is_reading) { + /* For reads add per_dev sglist array */ + /* TODO: Raid 6 we need twice more. Actually: + * num_stripes / LCMdP(W,P); + * if (W%P != 0) num_stripes *= parity; + */ + + /* first/last seg is split */ + num_raid_units += layout->group_width; + sgs_per_dev = div_u64(num_raid_units, data_devs); + } else { + /* For Writes add parity pages array. */ + max_par_pages = num_raid_units * pages_in_unit * + sizeof(struct page *); + } + } + + ret = _ore_get_io_state(layout, oc, numdevs, sgs_per_dev, max_par_pages, + pios); if (unlikely(ret)) return ret; @@ -189,10 +267,11 @@ int ore_get_rw_state(struct ore_layout *layout, struct ore_components *oc, ios->offset = offset; if (length) { - ore_calc_stripe_info(layout, offset, &ios->si); - ios->length = (length <= ios->si.group_length) ? length : - ios->si.group_length; + ore_calc_stripe_info(layout, offset, length, &ios->si); + ios->length = ios->si.length; ios->nr_pages = (ios->length + PAGE_SIZE - 1) / PAGE_SIZE; + if (layout->parity) + _ore_post_alloc_raid_stuff(ios); } return 0; @@ -209,7 +288,7 @@ EXPORT_SYMBOL(ore_get_rw_state); int ore_get_io_state(struct ore_layout *layout, struct ore_components *oc, struct ore_io_state **pios) { - return _get_io_state(layout, oc, oc->numdevs, pios); + return _ore_get_io_state(layout, oc, oc->numdevs, 0, 0, pios); } EXPORT_SYMBOL(ore_get_io_state); @@ -227,6 +306,7 @@ void ore_put_io_state(struct ore_io_state *ios) bio_put(per_dev->bio); } + _ore_free_raid_stuff(ios); kfree(ios); } } @@ -367,53 +447,65 @@ EXPORT_SYMBOL(ore_check_io); /* * L - logical offset into the file * - * U - The number of bytes in a stripe within a group + * D - number of Data devices + * D = group_width - parity * - * U = stripe_unit * group_width + * U - The number of bytes in a stripe within a group + * U = stripe_unit * D * * T - The number of bytes striped within a group of component objects * (before advancing to the next group) - * - * T = stripe_unit * group_width * group_depth + * T = U * group_depth * * S - The number of bytes striped across all component objects * before the pattern repeats + * S = T * group_count * - * S = stripe_unit * group_width * group_depth * group_count - * - * M - The "major" (i.e., across all components) stripe number - * + * M - The "major" (i.e., across all components) cycle number * M = L / S * - * G - Counts the groups from the beginning of the major stripe - * + * G - Counts the groups from the beginning of the major cycle * G = (L - (M * S)) / T [or (L % S) / T] * * H - The byte offset within the group - * * H = (L - (M * S)) % T [or (L % S) % T] * * N - The "minor" (i.e., across the group) stripe number - * * N = H / U * * C - The component index coresponding to L * - * C = (H - (N * U)) / stripe_unit + G * group_width - * [or (L % U) / stripe_unit + G * group_width] + * C = (H - (N * U)) / stripe_unit + G * D + * [or (L % U) / stripe_unit + G * D] * * O - The component offset coresponding to L - * * O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit + * + * LCMdP – Parity cycle: Lowest Common Multiple of group_width, parity + * divide by parity + * LCMdP = lcm(group_width, parity) / parity + * + * R - The parity Rotation stripe + * (Note parity cycle always starts at a group's boundary) + * R = N % LCMdP + * + * I = the first parity device index + * I = (group_width + group_width - R*parity - parity) % group_width + * + * Craid - The component index Rotated + * Craid = (group_width + C - R*parity) % group_width + * (We add the group_width to avoid negative numbers modulo math) */ void ore_calc_stripe_info(struct ore_layout *layout, u64 file_offset, - struct ore_striping_info *si) + u64 length, struct ore_striping_info *si) { u32 stripe_unit = layout->stripe_unit; u32 group_width = layout->group_width; u64 group_depth = layout->group_depth; + u32 parity = layout->parity; - u32 U = stripe_unit * group_width; + u32 D = group_width - parity; + u32 U = D * stripe_unit; u64 T = U * group_depth; u64 S = T * layout->group_count; u64 M = div64_u64(file_offset, S); @@ -429,22 +521,43 @@ void ore_calc_stripe_info(struct ore_layout *layout, u64 file_offset, u32 N = div_u64(H, U); /* "H - (N * U)" is just "H % U" so it's bound to u32 */ - si->dev = (u32)(H - (N * U)) / stripe_unit + G * group_width; - si->dev *= layout->mirrors_p1; + u32 C = (u32)(H - (N * U)) / stripe_unit + G * group_width; div_u64_rem(file_offset, stripe_unit, &si->unit_off); si->obj_offset = si->unit_off + (N * stripe_unit) + (M * group_depth * stripe_unit); - si->group_length = T - H; + if (parity) { + u32 LCMdP = lcm(group_width, parity) / parity; + /* R = N % LCMdP; */ + u32 RxP = (N % LCMdP) * parity; + u32 first_dev = C - C % group_width; + + si->par_dev = (group_width + group_width - parity - RxP) % + group_width + first_dev; + si->dev = (group_width + C - RxP) % group_width + first_dev; + si->bytes_in_stripe = U; + si->first_stripe_start = M * S + G * T + N * U; + } else { + /* Make the math correct see _prepare_one_group */ + si->par_dev = group_width; + si->dev = C; + } + + si->dev *= layout->mirrors_p1; + si->par_dev *= layout->mirrors_p1; + si->offset = file_offset; + si->length = T - H; + if (si->length > length) + si->length = length; si->M = M; } EXPORT_SYMBOL(ore_calc_stripe_info); -static int _add_stripe_unit(struct ore_io_state *ios, unsigned *cur_pg, - unsigned pgbase, struct ore_per_dev_state *per_dev, - int cur_len) +int _ore_add_stripe_unit(struct ore_io_state *ios, unsigned *cur_pg, + unsigned pgbase, struct page **pages, + struct ore_per_dev_state *per_dev, int cur_len) { unsigned pg = *cur_pg; struct request_queue *q = @@ -455,8 +568,11 @@ static int _add_stripe_unit(struct ore_io_state *ios, unsigned *cur_pg, if (per_dev->bio == NULL) { unsigned pages_in_stripe = ios->layout->group_width * (ios->layout->stripe_unit / PAGE_SIZE); - unsigned bio_size = (ios->nr_pages + pages_in_stripe) / - ios->layout->group_width; + unsigned nr_pages = ios->nr_pages * ios->layout->group_width / + (ios->layout->group_width - + ios->layout->parity); + unsigned bio_size = (nr_pages + pages_in_stripe) / + ios->layout->group_width; per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size); if (unlikely(!per_dev->bio)) { @@ -471,12 +587,13 @@ static int _add_stripe_unit(struct ore_io_state *ios, unsigned *cur_pg, unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len); unsigned added_len; - BUG_ON(ios->nr_pages <= pg); cur_len -= pglen; - added_len = bio_add_pc_page(q, per_dev->bio, ios->pages[pg], + added_len = bio_add_pc_page(q, per_dev->bio, pages[pg], pglen, pgbase); if (unlikely(pglen != added_len)) { + ORE_DBGMSG("Failed bio_add_pc_page bi_vcnt=%u\n", + per_dev->bio->bi_vcnt); ret = -ENOMEM; goto out; } @@ -501,9 +618,11 @@ static int _prepare_for_striping(struct ore_io_state *ios) struct ore_striping_info *si = &ios->si; unsigned stripe_unit = ios->layout->stripe_unit; unsigned mirrors_p1 = ios->layout->mirrors_p1; - unsigned devs_in_group = ios->layout->group_width * mirrors_p1; + unsigned group_width = ios->layout->group_width; + unsigned devs_in_group = group_width * mirrors_p1; unsigned dev = si->dev; unsigned first_dev = dev - (dev % devs_in_group); + unsigned dev_order; unsigned cur_pg = ios->pages_consumed; u64 length = ios->length; int ret = 0; @@ -513,7 +632,10 @@ static int _prepare_for_striping(struct ore_io_state *ios) return 0; } - BUG_ON(length > si->group_length); + BUG_ON(length > si->length); + + dev_order = _dev_order(devs_in_group, mirrors_p1, si->par_dev, dev); + si->cur_comp = dev_order; while (length) { unsigned comp = dev - first_dev; @@ -522,17 +644,20 @@ static int _prepare_for_striping(struct ore_io_state *ios) if (!per_dev->length) { per_dev->dev = dev; - if (dev < si->dev) { - per_dev->offset = si->obj_offset + stripe_unit - - si->unit_off; - cur_len = stripe_unit; - } else if (dev == si->dev) { + if (dev == si->dev) { + WARN_ON(dev == si->par_dev); per_dev->offset = si->obj_offset; cur_len = stripe_unit - si->unit_off; page_off = si->unit_off & ~PAGE_MASK; BUG_ON(page_off && (page_off != ios->pgbase)); - } else { /* dev > si->dev */ - per_dev->offset = si->obj_offset - si->unit_off; + } else { + if (si->cur_comp > dev_order) + per_dev->offset = + si->obj_offset - si->unit_off; + else /* si->cur_comp < dev_order */ + per_dev->offset = + si->obj_offset + stripe_unit - + si->unit_off; cur_len = stripe_unit; } } else { @@ -541,8 +666,8 @@ static int _prepare_for_striping(struct ore_io_state *ios) if (cur_len >= length) cur_len = length; - ret = _add_stripe_unit(ios, &cur_pg, page_off , per_dev, - cur_len); + ret = _ore_add_stripe_unit(ios, &cur_pg, page_off, ios->pages, + per_dev, cur_len); if (unlikely(ret)) goto out; @@ -550,6 +675,41 @@ static int _prepare_for_striping(struct ore_io_state *ios) dev = (dev % devs_in_group) + first_dev; length -= cur_len; + + si->cur_comp = (si->cur_comp + 1) % group_width; + if (unlikely((dev == si->par_dev) || + (!length && ios->parity_pages))) { + if (!length) + /* If we are writing and this is the very last + * stripe. then operate on parity dev. + */ + dev = si->par_dev; + if (ios->reading) + /* In writes cur_len just means if it's the + * last one. See _ore_add_parity_unit. + */ + cur_len = length; + per_dev = &ios->per_dev[dev - first_dev]; + if (!per_dev->length) { + /* Only/always the parity unit of the first + * stripe will be empty. So this is a chance to + * initialize the per_dev info. + */ + per_dev->dev = dev; + per_dev->offset = si->obj_offset - si->unit_off; + } + + ret = _ore_add_parity_unit(ios, si, per_dev, cur_len); + if (unlikely(ret)) + goto out; + + /* Rotate next par_dev backwards with wraping */ + si->par_dev = (devs_in_group + si->par_dev - + ios->layout->parity * mirrors_p1) % + devs_in_group + first_dev; + /* Next stripe, start fresh */ + si->cur_comp = 0; + } } out: ios->numdevs = devs_in_group; @@ -747,12 +907,24 @@ static int _read_mirror(struct ore_io_state *ios, unsigned cur_comp) per_dev->or = or; if (ios->pages) { - osd_req_read(or, obj, per_dev->offset, - per_dev->bio, per_dev->length); + if (per_dev->cur_sg) { + /* finalize the last sg_entry */ + _ore_add_sg_seg(per_dev, 0, false); + if (unlikely(!per_dev->cur_sg)) + return 0; /* Skip parity only device */ + + osd_req_read_sg(or, obj, per_dev->bio, + per_dev->sglist, per_dev->cur_sg); + } else { + /* The no raid case */ + osd_req_read(or, obj, per_dev->offset, + per_dev->bio, per_dev->length); + } + ORE_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx" - " dev=%d\n", _LLU(obj->id), + " dev=%d sg_len=%d\n", _LLU(obj->id), _LLU(per_dev->offset), _LLU(per_dev->length), - first_dev); + first_dev, per_dev->cur_sg); } else { BUG_ON(ios->kern_buff); @@ -849,7 +1021,7 @@ static void _calc_trunk_info(struct ore_layout *layout, u64 file_offset, { unsigned stripe_unit = layout->stripe_unit; - ore_calc_stripe_info(layout, file_offset, &ti->si); + ore_calc_stripe_info(layout, file_offset, 0, &ti->si); ti->prev_group_obj_off = ti->si.M * stripe_unit; ti->next_group_obj_off = ti->si.M ? (ti->si.M - 1) * stripe_unit : 0; diff --git a/fs/exofs/ore_raid.c b/fs/exofs/ore_raid.c new file mode 100644 index 00000000000..8d4b93a93c6 --- /dev/null +++ b/fs/exofs/ore_raid.c @@ -0,0 +1,140 @@ +/* + * Copyright (C) 2011 + * Boaz Harrosh <bharrosh@panasas.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 "ore_raid.h" + +struct page *_raid_page_alloc(void) +{ + return alloc_page(GFP_KERNEL); +} + +void _raid_page_free(struct page *p) +{ + __free_page(p); +} + +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; + } +} + +/* 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) +{ + if (ios->reading) { + BUG_ON(per_dev->cur_sg >= ios->sgs_per_dev); + _ore_add_sg_seg(per_dev, cur_len, true); + } else { + struct page **pages = ios->parity_pages + ios->cur_par_page; + unsigned num_pages = ios->layout->stripe_unit / PAGE_SIZE; + unsigned array_start = 0; + unsigned i; + int ret; + + for (i = 0; i < num_pages; i++) { + pages[i] = _raid_page_alloc(); + if (unlikely(!pages[i])) + return -ENOMEM; + + ++(ios->cur_par_page); + /* TODO: only read support for now */ + clear_highpage(pages[i]); + } + + ORE_DBGMSG("writing dev=%d num_pages=%d cur_par_page=%d", + per_dev->dev, num_pages, ios->cur_par_page); + + ret = _ore_add_stripe_unit(ios, &array_start, 0, pages, + per_dev, num_pages * PAGE_SIZE); + if (unlikely(ret)) + return ret; + } + return 0; +} + +int _ore_post_alloc_raid_stuff(struct ore_io_state *ios) +{ + /*TODO: Only raid writes has stuff to add here */ + return 0; +} + +void _ore_free_raid_stuff(struct ore_io_state *ios) +{ + if (ios->parity_pages) { /* 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); + } else { + /* Will only be set if raid reading && sglist is big */ + if (ios->extra_part_alloc) + kfree(ios->per_dev[0].sglist); + } +} diff --git a/fs/exofs/ore_raid.h b/fs/exofs/ore_raid.h new file mode 100644 index 00000000000..c21080b4407 --- /dev/null +++ b/fs/exofs/ore_raid.h @@ -0,0 +1,64 @@ +/* + * Copyright (C) from 2011 + * Boaz Harrosh <bharrosh@panasas.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 <scsi/osd_ore.h> + +#define ORE_ERR(fmt, a...) printk(KERN_ERR "ore: " fmt, ##a) + +#ifdef CONFIG_EXOFS_DEBUG +#define ORE_DBGMSG(fmt, a...) \ + printk(KERN_NOTICE "ore @%s:%d: " fmt, __func__, __LINE__, ##a) +#else +#define ORE_DBGMSG(fmt, a...) \ + do { if (0) printk(fmt, ##a); } while (0) +#endif + +/* u64 has problems with printk this will cast it to unsigned long long */ +#define _LLU(x) (unsigned long long)(x) + +#define ORE_DBGMSG2(M...) do {} while (0) +/* #define ORE_DBGMSG2 ORE_DBGMSG */ + +/* Calculate the component order in a stripe. eg the logical data unit + * address within the stripe of @dev given the @par_dev of this stripe. + */ +static inline unsigned _dev_order(unsigned devs_in_group, unsigned mirrors_p1, + unsigned par_dev, unsigned dev) +{ + unsigned first_dev = dev - dev % devs_in_group; + + dev -= first_dev; + par_dev -= first_dev; + + if (devs_in_group == par_dev) /* The raid 0 case */ + return dev / mirrors_p1; + /* raid4/5/6 case */ + return ((devs_in_group + dev - par_dev - mirrors_p1) % devs_in_group) / + mirrors_p1; +} + +/* ios_raid.c stuff needed by ios.c */ +int _ore_post_alloc_raid_stuff(struct ore_io_state *ios); +void _ore_free_raid_stuff(struct ore_io_state *ios); + +void _ore_add_sg_seg(struct ore_per_dev_state *per_dev, unsigned cur_len, + bool not_last); +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); + +/* ios.c stuff needed by ios_raid.c */ +int _ore_add_stripe_unit(struct ore_io_state *ios, unsigned *cur_pg, + unsigned pgbase, struct page **pages, + struct ore_per_dev_state *per_dev, int cur_len); |