#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");
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;
{
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;
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;
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);
bio_put(per_dev->bio);
}
+ _ore_free_raid_stuff(ios);
kfree(ios);
}
}
/*
* 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);
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 =
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)) {
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;
}
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;
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;
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 {
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;
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;
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);
{
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;
--- /dev/null
+/*
+ * 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);
+ }
+}
git.openpandora.org / pandora-kernel.git / commitdiff