This simple patch adds support for raid6 to the ORE.
Most operations and calculations where already for the general
case. Only things left:
* call async_gen_syndrome() in the case of raid6
(NOTE that the raid6 math is the one supported by the Linux Kernel
see: crypto/async_tx/async_pq.c)
* call _ore_add_parity_unit() twice with only last call generating
the redundancy pages.
* Fix couple BUGS in old code
a. In reads when parity==2 it can happen that per_dev->length=0
but per_dev->offset was set and adjusted by _ore_add_sg_seg().
Don't let it be overwritten.
b. The all 'cur_comp > starting_dev' thing to determine if:
"per_dev->offset is in the current stripe number or the
next one."
Was a complete raid5/4 *accident*. When parity==2 this is not
at all true usually. All we need to do is increment si->ob_offset
once we pass by the first parity device.
(This also greatly simplifies the code, amen)
c. Calculation of si->dev rotation can overflow when parity==2.
* Then last enable raid6 in ore_verify_layout()
Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
---
fs/exofs/Kconfig.ore | 2 ++
fs/exofs/ore.c | 77 ++++++++++++++++++++++++++++++++++++----------------
fs/exofs/ore_raid.c | 37 ++++++++++++++++---------
fs/exofs/ore_raid.h | 3 +-
4 files changed, 81 insertions(+), 38 deletions(-)
diff --git a/fs/exofs/Kconfig.ore b/fs/exofs/Kconfig.ore
index 1ca7fb7..2daf232 100644
--- a/fs/exofs/Kconfig.ore
+++ b/fs/exofs/Kconfig.ore
@@ -9,4 +9,6 @@ config ORE
tristate
depends on EXOFS_FS || PNFS_OBJLAYOUT
select ASYNC_XOR
+ select RAID6_PQ
+ select ASYNC_PQ
default SCSI_OSD_ULD
diff --git a/fs/exofs/ore.c b/fs/exofs/ore.c
index 2de488d..cfc0205 100644
--- a/fs/exofs/ore.c
+++ b/fs/exofs/ore.c
@@ -58,9 +58,12 @@ int ore_verify_layout(unsigned total_comps, struct ore_layout *layout)
layout->parity = 1;
break;
case PNFS_OSD_RAID_PQ:
+ layout->parity = 2;
+ break;
case PNFS_OSD_RAID_4:
default:
- ORE_ERR("Only RAID_0/5 for now\n");
+ ORE_ERR("Only RAID_0/5/6 for now received-enum=%d\n",
+ layout->raid_algorithm);
return -EINVAL;
}
if (0 != (layout->stripe_unit & ~PAGE_MASK)) {
@@ -112,6 +115,8 @@ int ore_verify_layout(unsigned total_comps, struct ore_layout *layout)
layout->max_io_length /= stripe_length;
layout->max_io_length *= stripe_length;
}
+ ORE_DBGMSG("max_io_length=0x%lx\n", layout->max_io_length);
+
return 0;
}
EXPORT_SYMBOL(ore_verify_layout);
@@ -561,7 +566,8 @@ void ore_calc_stripe_info(struct ore_layout *layout, u64 file_offset,
si->par_dev = (group_width + group_width - parity - RxP) %
group_width + first_dev;
- si->dev = (group_width + C - RxP) % group_width + first_dev;
+ si->dev = (group_width + group_width + C - RxP) %
+ group_width + first_dev;
si->bytes_in_stripe = U;
si->first_stripe_start = M * S + G * T + N * U;
} else {
@@ -651,6 +657,43 @@ out: /* we fail the complete unit on an error eg don't advance
return ret;
}
+static int _add_parity_units(struct ore_io_state *ios,
+ struct ore_striping_info *si,
+ unsigned dev, unsigned first_dev,
+ unsigned mirrors_p1, unsigned devs_in_group,
+ unsigned cur_len)
+{
+ unsigned do_parity;
+ int ret = 0;
+
+ for (do_parity = ios->layout->parity; do_parity; --do_parity) {
+ struct ore_per_dev_state *per_dev;
+
+ per_dev = &ios->per_dev[dev - first_dev];
+ if (!per_dev->length && !per_dev->offset) {
+ /* 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,
+ do_parity == 1);
+ if (unlikely(ret))
+ break;
+
+ if (do_parity != 1) {
+ dev = ((dev + mirrors_p1) % devs_in_group) + first_dev;
+ si->cur_comp = (si->cur_comp + 1) %
+ ios->layout->group_width;
+ }
+ }
+
+ return ret;
+}
+
static int _prepare_for_striping(struct ore_io_state *ios)
{
struct ore_striping_info *si = &ios->si;
@@ -660,7 +703,6 @@ static int _prepare_for_striping(struct ore_io_state *ios)
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;
@@ -672,14 +714,13 @@ static int _prepare_for_striping(struct ore_io_state *ios)
BUG_ON(length > si->length);
- dev_order = si->cur_comp;
-
while (length) {
struct ore_per_dev_state *per_dev =
&ios->per_dev[dev - first_dev];
unsigned cur_len, page_off = 0;
- if (!per_dev->length) {
+ if (!per_dev->length && !per_dev->offset) {
+ /* First time initialize the per_dev info. */
per_dev->dev = dev;
if (dev == si->dev) {
WARN_ON(dev == si->par_dev);
@@ -688,13 +729,7 @@ static int _prepare_for_striping(struct ore_io_state *ios)
page_off = si->unit_off & ~PAGE_MASK;
BUG_ON(page_off && (page_off != ios->pgbase));
} 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;
+ per_dev->offset = si->obj_offset - si->unit_off;
cur_len = stripe_unit;
}
} else {
@@ -721,21 +756,13 @@ static int _prepare_for_striping(struct ore_io_state *ios)
/* If last stripe operate on parity comp */
si->cur_comp = group_width - ios->layout->parity;
}
- 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;
- }
/* In writes cur_len just means if it's the
* last one. See _ore_add_parity_unit.
*/
- ret = _ore_add_parity_unit(ios, si, per_dev,
- ios->sp2d : length : cur_len);
+ ret = _add_parity_units(ios, si, dev, first_dev,
+ mirrors_p1, devs_in_group,
+ ios->sp2d ? length : cur_len);
if (unlikely(ret))
goto out;
@@ -746,6 +773,8 @@ static int _prepare_for_striping(struct ore_io_state *ios)
/* Next stripe, start fresh */
si->cur_comp = 0;
si->cur_pg = 0;
+ si->obj_offset += cur_len;
+ si->unit_off = 0;
}
}
out:
diff --git a/fs/exofs/ore_raid.c b/fs/exofs/ore_raid.c
index d58a952..7f20f25 100644
--- a/fs/exofs/ore_raid.c
+++ b/fs/exofs/ore_raid.c
@@ -218,20 +218,28 @@ static unsigned _sp2d_max_pg(struct __stripe_pages_2d *sp2d)
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,
- ASYNC_TX_XOR_ZERO_DST | ASYNC_TX_ACK,
+ init_async_submit(&_1ps->submit, tx_flags,
NULL, NULL, NULL, (addr_conv_t *)_1ps->scribble);
- /* TODO: raid6 */
- _1ps->tx = async_xor(_1ps->pages[sp2d->data_devs], _1ps->pages,
- 0, sp2d->data_devs, PAGE_SIZE,
- &_1ps->submit);
+ 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++) {
@@ -616,7 +624,7 @@ static int _read_4_write_execute(struct ore_io_state *ios)
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)
+ unsigned cur_len, bool do_xor)
{
if (ios->reading) {
if (per_dev->cur_sg >= ios->sgs_per_dev) {
@@ -641,9 +649,11 @@ int _ore_add_parity_unit(struct ore_io_state *ios,
/* If first stripe, Read in all read4write pages
* (if needed) before we calculate the first parity.
*/
- _read_4_write_first_stripe(ios);
+ if (do_xor)
+ _read_4_write_first_stripe(ios);
}
- if (!cur_len) /* If last stripe r4w pages of last stripe */
+ if (!cur_len && do_xor)
+ /* If last stripe r4w pages of last stripe */
_read_4_write_last_stripe(ios);
_read_4_write_execute(ios);
@@ -655,7 +665,7 @@ int _ore_add_parity_unit(struct ore_io_state *ios,
++(ios->cur_par_page);
}
- BUG_ON(si->cur_comp != sp2d->data_devs);
+ 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,
@@ -663,9 +673,10 @@ int _ore_add_parity_unit(struct ore_io_state *ios,
if (unlikely(ret))
return ret;
- /* TODO: raid6 if (last_parity_dev) */
- _gen_xor_unit(sp2d);
- _sp2d_reset(sp2d, ios->r4w, ios->private);
+ if (do_xor) {
+ _gen_xor_unit(sp2d);
+ _sp2d_reset(sp2d, ios->r4w, ios->private);
+ }
}
return 0;
}
diff --git a/fs/exofs/ore_raid.h b/fs/exofs/ore_raid.h
index d365bda..cf6375d 100644
--- a/fs/exofs/ore_raid.h
+++ b/fs/exofs/ore_raid.h
@@ -38,7 +38,8 @@ 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);
+ struct ore_per_dev_state *per_dev, unsigned cur_len,
+ bool do_xor);
void _ore_add_stripe_page(struct __stripe_pages_2d *sp2d,
struct ore_striping_info *si, struct page *page);
static inline void _add_stripe_page(struct __stripe_pages_2d *sp2d,
--
1.9.0
--
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