* [PATCH 08/16] md/bitmap: Rename a jump label in location_store()
From: SF Markus Elfring @ 2016-09-27 16:55 UTC (permalink / raw)
To: linux-raid, Shaohua Li; +Cc: LKML, kernel-janitors, Julia Lawall
In-Reply-To: <30938c84-20a7-0f13-bdda-a2d2109a6dac@users.sourceforge.net>
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 27 Sep 2016 15:46:22 +0200
Adjust jump labels according to the current Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/md/bitmap.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 41d99fd..22fa09a 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -2187,11 +2187,11 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
if (mddev->pers) {
if (!mddev->pers->quiesce) {
rv = -EBUSY;
- goto out;
+ goto unlock;
}
if (mddev->recovery || mddev->sync_thread) {
rv = -EBUSY;
- goto out;
+ goto unlock;
}
}
@@ -2200,7 +2200,7 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
/* bitmap already configured. Only option is to clear it */
if (strncmp(buf, "none", 4) != 0) {
rv = -EBUSY;
- goto out;
+ goto unlock;
}
if (mddev->pers) {
mddev->pers->quiesce(mddev, 1);
@@ -2221,23 +2221,23 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
else if (strncmp(buf, "file:", 5) == 0) {
/* Not supported yet */
rv = -EINVAL;
- goto out;
+ goto unlock;
} else {
if (buf[0] == '+')
rv = kstrtoll(buf+1, 10, &offset);
else
rv = kstrtoll(buf, 10, &offset);
if (rv)
- goto out;
+ goto unlock;
if (offset == 0) {
rv = -EINVAL;
- goto out;
+ goto unlock;
}
if (mddev->bitmap_info.external == 0 &&
mddev->major_version == 0 &&
offset != mddev->bitmap_info.default_offset) {
rv = -EINVAL;
- goto out;
+ goto unlock;
}
mddev->bitmap_info.offset = offset;
if (mddev->pers) {
@@ -2255,7 +2255,7 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
mddev->pers->quiesce(mddev, 0);
if (rv) {
bitmap_destroy(mddev);
- goto out;
+ goto unlock;
}
}
}
@@ -2268,7 +2268,7 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
md_wakeup_thread(mddev->thread);
}
rv = 0;
-out:
+unlock:
mddev_unlock(mddev);
if (rv)
return rv;
--
2.10.0
^ permalink raw reply related
* [PATCH 07/16] md/bitmap: Replace a kzalloc() call by kcalloc() in bitmap_resize()
From: SF Markus Elfring @ 2016-09-27 16:54 UTC (permalink / raw)
To: linux-raid, Shaohua Li; +Cc: LKML, kernel-janitors, Julia Lawall
In-Reply-To: <30938c84-20a7-0f13-bdda-a2d2109a6dac@users.sourceforge.net>
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 27 Sep 2016 15:26:51 +0200
The script "checkpatch.pl" can point information out like the following.
WARNING: Prefer kcalloc over kzalloc with multiply
Thus fix the affected source code place.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/md/bitmap.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 2d30c83..41d99fd 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -2035,8 +2035,7 @@ int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
return ret;
pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
-
- new_bp = kzalloc(pages * sizeof(*new_bp), GFP_KERNEL);
+ new_bp = kcalloc(pages, sizeof(*new_bp), GFP_KERNEL);
if (!new_bp) {
bitmap_file_unmap(&store);
return -ENOMEM;
--
2.10.0
^ permalink raw reply related
* [PATCH 06/16] md/bitmap: Return directly after a failed kzalloc() in bitmap_resize()
From: SF Markus Elfring @ 2016-09-27 16:53 UTC (permalink / raw)
To: linux-raid, Shaohua Li; +Cc: LKML, kernel-janitors, Julia Lawall
In-Reply-To: <30938c84-20a7-0f13-bdda-a2d2109a6dac@users.sourceforge.net>
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 27 Sep 2016 15:21:23 +0200
* Return directly after a call of the function "kzalloc" failed here.
* Delete two assignments for the local variable "ret" and the jump
target "err" which became unnecessary with this refactoring.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/md/bitmap.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 5092bc0..2d30c83 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -2037,10 +2037,9 @@ int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
new_bp = kzalloc(pages * sizeof(*new_bp), GFP_KERNEL);
- ret = -ENOMEM;
if (!new_bp) {
bitmap_file_unmap(&store);
- goto err;
+ return -ENOMEM;
}
if (!init)
@@ -2160,8 +2159,6 @@ int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
bitmap_unplug(bitmap);
bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
}
- ret = 0;
-err:
return ret;
}
EXPORT_SYMBOL_GPL(bitmap_resize);
--
2.10.0
^ permalink raw reply related
* [PATCH 05/16] md/bitmap: Return directly after a failed bitmap_storage_alloc() in bitmap_resize()
From: SF Markus Elfring @ 2016-09-27 16:51 UTC (permalink / raw)
To: linux-raid, Shaohua Li; +Cc: LKML, kernel-janitors, Julia Lawall
In-Reply-To: <30938c84-20a7-0f13-bdda-a2d2109a6dac@users.sourceforge.net>
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 27 Sep 2016 14:47:29 +0200
Return directly after a memory allocation failed in this function
at the beginning.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/md/bitmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index c278865..5092bc0 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -2032,7 +2032,7 @@ int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
mddev_is_clustered(bitmap->mddev)
? bitmap->cluster_slot : 0);
if (ret)
- goto err;
+ return ret;
pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
--
2.10.0
^ permalink raw reply related
* [PATCH 04/16] md/bitmap: Improve another size determination in bitmap_storage_alloc()
From: SF Markus Elfring @ 2016-09-27 16:50 UTC (permalink / raw)
To: linux-raid, Shaohua Li; +Cc: LKML, kernel-janitors, Julia Lawall
In-Reply-To: <30938c84-20a7-0f13-bdda-a2d2109a6dac@users.sourceforge.net>
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 27 Sep 2016 14:19:00 +0200
Replace the specification of a data type by a pointer dereference
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/md/bitmap.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 9b3f723..c278865 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -791,9 +791,9 @@ static int bitmap_storage_alloc(struct bitmap_storage *store,
/* We need 4 bits per page, rounded up to a multiple
* of sizeof(unsigned long) */
- store->filemap_attr = kzalloc(
- roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
- GFP_KERNEL);
+ store->filemap_attr = kzalloc(roundup(DIV_ROUND_UP(num_pages * 4, 8),
+ sizeof(*store->filemap_attr)),
+ GFP_KERNEL);
if (!store->filemap_attr)
return -ENOMEM;
--
2.10.0
^ permalink raw reply related
* [PATCH 03/16] md/bitmap: Delete an unnecessary variable initialisation in bitmap_storage_alloc()
From: SF Markus Elfring @ 2016-09-27 16:49 UTC (permalink / raw)
To: linux-raid, Shaohua Li; +Cc: LKML, kernel-janitors, Julia Lawall
In-Reply-To: <30938c84-20a7-0f13-bdda-a2d2109a6dac@users.sourceforge.net>
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 27 Sep 2016 13:20:23 +0200
The local variable "offset" will be set to an appropriate value a bit later.
Thus omit the explicit initialisation at the beginning.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/md/bitmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 78512c6..9b3f723 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -750,7 +750,7 @@ static int bitmap_storage_alloc(struct bitmap_storage *store,
unsigned long chunks, int with_super,
int slot_number)
{
- int pnum, offset = 0;
+ int pnum, offset;
unsigned long num_pages;
unsigned long bytes;
--
2.10.0
^ permalink raw reply related
* [PATCH 02/16] md/bitmap: Move an assignment for the variable "offset" in bitmap_storage_alloc()
From: SF Markus Elfring @ 2016-09-27 16:48 UTC (permalink / raw)
To: linux-raid, Shaohua Li; +Cc: LKML, kernel-janitors, Julia Lawall
In-Reply-To: <30938c84-20a7-0f13-bdda-a2d2109a6dac@users.sourceforge.net>
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 27 Sep 2016 13:10:05 +0200
Move the assignment for the local variable "offset" behind
the source code for memory allocations by this function.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/md/bitmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 8cfb02c..78512c6 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -759,7 +759,6 @@ static int bitmap_storage_alloc(struct bitmap_storage *store,
bytes += sizeof(bitmap_super_t);
num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
- offset = slot_number * num_pages;
store->filemap = kmalloc_array(num_pages,
sizeof(*store->filemap),
GFP_KERNEL);
@@ -772,6 +771,7 @@ static int bitmap_storage_alloc(struct bitmap_storage *store,
return -ENOMEM;
}
+ offset = slot_number * num_pages;
pnum = 0;
if (store->sb_page) {
store->filemap[0] = store->sb_page;
--
2.10.0
^ permalink raw reply related
* [PATCH 01/16] md/bitmap: Use kmalloc_array() in bitmap_storage_alloc()
From: SF Markus Elfring @ 2016-09-27 16:45 UTC (permalink / raw)
To: linux-raid, Shaohua Li; +Cc: LKML, kernel-janitors, Julia Lawall
In-Reply-To: <30938c84-20a7-0f13-bdda-a2d2109a6dac@users.sourceforge.net>
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 27 Sep 2016 13:01:07 +0200
* A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus use the corresponding function "kmalloc_array".
This issue was detected by using the Coccinelle software.
* Replace the specification of a data type by a pointer dereference
to make the corresponding size determination a bit safer according to
the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/md/bitmap.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 13041ee..8cfb02c 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -760,9 +760,9 @@ static int bitmap_storage_alloc(struct bitmap_storage *store,
num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
offset = slot_number * num_pages;
-
- store->filemap = kmalloc(sizeof(struct page *)
- * num_pages, GFP_KERNEL);
+ store->filemap = kmalloc_array(num_pages,
+ sizeof(*store->filemap),
+ GFP_KERNEL);
if (!store->filemap)
return -ENOMEM;
--
2.10.0
^ permalink raw reply related
* Re: WARNING: mismatch_cnt is not 0 on <array device>
From: Wols Lists @ 2016-09-27 16:45 UTC (permalink / raw)
To: Benjammin2068, Linux-RAID
In-Reply-To: <41c176d2-0235-6ff0-996c-b32dc95d487d@gmail.com>
On 27/09/16 17:27, Benjammin2068 wrote:
> p.s. The Linux RAID Wiki doesn't cover mismatch_cnt at all.... would be kinda nice considering how critical (or not) this is... and what to do about it.
I'm thinking about all this. The second section is all about recovering
a failing/ed array, and is new. The first section is the original,
that's being updated. It just feels totally wrong to me now, as it's
becoming a jumbled mess of old and new.
What I'm probably going to do, is create a new first section about
setting up a raid system. That means that a section on monitoring will
actually make sense and fit between setting it up, and fixing problems.
(And all the old stuff will end up in the "software archaeology"
section, so people who are still running ancient systems can find it :-)
Cheers,
Wol
^ permalink raw reply
* [PATCH 00/16] md/bitmap: Fine-tuning for several function implementations
From: SF Markus Elfring @ 2016-09-27 16:44 UTC (permalink / raw)
To: linux-raid, Shaohua Li; +Cc: LKML, kernel-janitors, Julia Lawall
In-Reply-To: <566ABCD9.1060404@users.sourceforge.net>
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 27 Sep 2016 18:29:08 +0200
Several update suggestions were taken into account
from static source code analysis.
Markus Elfring (16):
Use kmalloc_array() in bitmap_storage_alloc()
Move an assignment for the variable "offset" in bitmap_storage_alloc()
Delete an unnecessary variable initialisation in bitmap_storage_alloc()
Improve another size determination in bitmap_storage_alloc()
Return directly after a failed bitmap_storage_alloc() in bitmap_resize()
Return directly after a failed kzalloc() in bitmap_resize()
Replace a kzalloc() call by kcalloc() in bitmap_resize()
Rename a jump label in location_store()
Rename a jump label in bitmap_copy_from_slot()
Rename a jump label in bitmap_create()
Rename a jump label in bitmap_init_from_disk()
One check less in read_page() at the end
Adjust checks for null pointers in 11 functions
Delete unnecessary braces in bitmap_resize()
Add spaces around three comparison operators
Delete an unwanted space in read_sb_page()
drivers/md/bitmap.c | 110 +++++++++++++++++++++++++---------------------------
1 file changed, 52 insertions(+), 58 deletions(-)
--
2.10.0
^ permalink raw reply
* Re: WARNING: mismatch_cnt is not 0 on <array device>
From: Roman Mamedov @ 2016-09-27 16:36 UTC (permalink / raw)
To: Benjammin2068; +Cc: Linux-RAID
In-Reply-To: <41c176d2-0235-6ff0-996c-b32dc95d487d@gmail.com>
[-- Attachment #1: Type: text/plain, Size: 733 bytes --]
On Tue, 27 Sep 2016 11:27:13 -0500
Benjammin2068 <benjammin2068@gmail.com> wrote:
> I think I did find the problem. The card was running hot due to airflow.
> That's been remedied (I hope) -- the temp sensor on the heat-sink for the
> PCIe controller now sits around 45'C which is fine. Before it was >=
> 60'C . :O
I wouldn't trust such controller anyway. 15 degrees difference and it
(allegedly) gives you silent data corruption? What if you have a particularly
hot day, and/or the AC is out for a few hours.
There is a lot of better failure modes than this (honestly reported read or
CRC errors for a start, or heck, even complete lock-up of the controller would
be more preferrable).
--
With respect,
Roman
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 181 bytes --]
^ permalink raw reply
* Re: WARNING: mismatch_cnt is not 0 on <array device>
From: Benjammin2068 @ 2016-09-27 16:27 UTC (permalink / raw)
To: Linux-RAID
In-Reply-To: <27577b8a-1b63-8f1a-9b68-b056622a5268@fnarfbargle.com>
On 09/27/2016 04:16 AM, Brad Campbell wrote:
> On 27/09/16 09:08, Benjammin2068 wrote:
>>
>
>> Also, I just did a "repair" and the mismatch is now back to 8... which seems like a suspicious number considering the filesystem on this new drive (because it's a WD10 series with 4096byte sectors) has a slightly larger FS than the Samsung HD103SJ (and Seagate equivalents) in the array too.
>
> See that is a bad thing to do if you even remotely suspect you have a problem. All a "repair" does is check the parity on a stripe and if there is a mismatch it re-writes it. You are writing to an array that apparently has issues.
>
> I'd be checking the filesystem and file contents very carefully for corruption, and running several sequential check actions to keep an eye on the mismatch count.
>
Yep.
Once I reconfig'd the hardware and checked the cables in the system on boot the number is now 0. (which makes sense at boot - but is creepy) I put a monitor into munin which I'll be watching closely for when it changes.
BUT... I think I did find the problem. The card was running hot due to airflow. That's been remedied (I hope) -- the temp sensor on the heat-sink for the PCIe controller now sits around 45'C which is fine. Before it was >= 60'C . :O
Thanks again everyone,
-Ben
p.s. The Linux RAID Wiki doesn't cover mismatch_cnt at all.... would be kinda nice considering how critical (or not) this is... and what to do about it.
^ permalink raw reply
* Re: WARNING: mismatch_cnt is not 0 on <array device>
From: Brad Campbell @ 2016-09-27 9:16 UTC (permalink / raw)
To: Benjammin2068, Phil Turmel, Linux-RAID
In-Reply-To: <c7bfde3e-0605-96d0-4e3d-fb76a9a8c724@gmail.com>
On 27/09/16 09:08, Benjammin2068 wrote:
>
> Also, I just did a "repair" and the mismatch is now back to 8... which seems like a suspicious number considering the filesystem on this new drive (because it's a WD10 series with 4096byte sectors) has a slightly larger FS than the Samsung HD103SJ (and Seagate equivalents) in the array too.
See that is a bad thing to do if you even remotely suspect you have a
problem. All a "repair" does is check the parity on a stripe and if
there is a mismatch it re-writes it. You are writing to an array that
apparently has issues.
I'd be checking the filesystem and file contents very carefully for
corruption, and running several sequential check actions to keep an eye
on the mismatch count.
^ permalink raw reply
* Re: WARNING: mismatch_cnt is not 0 on <array device>
From: Benjammin2068 @ 2016-09-27 6:42 UTC (permalink / raw)
To: Linux-RAID
In-Reply-To: <74e5712f-e89e-97af-8aa4-ae2948c02e94@turmel.org>
Well, I maybe found the problem.
1: I had an unhappy fan in the system -- and it's the one that cools the card slot area...
2: I think the controller card was getting warm anyway -- so I also changed the venting and put a temp sensor (CrystalFontz SCAB don'tcha know.. with dallas 1820 1-wire thermometers)... so I'm gonna keep an eye on it now.
3: I set up Munin to keep track of mismatch_cnt on all volumes. Didn't even know it existed.. :( wish I had history. I will now going forward.
I'll let ya'all know.
As usually... awesome help -- thanks!
-Ben
^ permalink raw reply
* [PATCH] md/raid5: use bool instead of int for some flags
From: JackieLiu @ 2016-09-27 1:40 UTC (permalink / raw)
To: shli; +Cc: linux-raid, JackieLiu
For flags, bool is a little better more or less than int.
Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
---
drivers/md/raid5.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ee7fc37..2861c3f 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -659,7 +659,7 @@ raid5_get_active_stripe(struct r5conf *conf, sector_t sector,
{
struct stripe_head *sh;
int hash = stripe_hash_locks_hash(sector);
- int inc_empty_inactive_list_flag;
+ bool inc_empty_inactive_list_flag;
pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
@@ -704,9 +704,9 @@ raid5_get_active_stripe(struct r5conf *conf, sector_t sector,
atomic_inc(&conf->active_stripes);
BUG_ON(list_empty(&sh->lru) &&
!test_bit(STRIPE_EXPANDING, &sh->state));
- inc_empty_inactive_list_flag = 0;
+ inc_empty_inactive_list_flag = false;
if (!list_empty(conf->inactive_list + hash))
- inc_empty_inactive_list_flag = 1;
+ inc_empty_inactive_list_flag = true;
list_del_init(&sh->lru);
if (list_empty(conf->inactive_list + hash) && inc_empty_inactive_list_flag)
atomic_inc(&conf->empty_inactive_list_nr);
@@ -768,7 +768,7 @@ static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh
sector_t head_sector, tmp_sec;
int hash;
int dd_idx;
- int inc_empty_inactive_list_flag;
+ bool inc_empty_inactive_list_flag;
/* Don't cross chunks, so stripe pd_idx/qd_idx is the same */
tmp_sec = sh->sector;
@@ -786,9 +786,9 @@ static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh
atomic_inc(&conf->active_stripes);
BUG_ON(list_empty(&head->lru) &&
!test_bit(STRIPE_EXPANDING, &head->state));
- inc_empty_inactive_list_flag = 0;
+ inc_empty_inactive_list_flag = false;
if (!list_empty(conf->inactive_list + hash))
- inc_empty_inactive_list_flag = 1;
+ inc_empty_inactive_list_flag = true;
list_del_init(&head->lru);
if (list_empty(conf->inactive_list + hash) && inc_empty_inactive_list_flag)
atomic_inc(&conf->empty_inactive_list_nr);
@@ -905,7 +905,7 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
return;
for (i = disks; i--; ) {
int op, op_flags = 0;
- int replace_only = 0;
+ bool replace_only = false;
struct bio *bi, *rbi;
struct md_rdev *rdev, *rrdev = NULL;
@@ -921,7 +921,7 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
else if (test_and_clear_bit(R5_WantReplace,
&sh->dev[i].flags)) {
op = REQ_OP_WRITE;
- replace_only = 1;
+ replace_only = true;
} else
continue;
if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags))
--
2.10.0
^ permalink raw reply related
* Re: WARNING: mismatch_cnt is not 0 on <array device>
From: Benjammin2068 @ 2016-09-27 1:08 UTC (permalink / raw)
To: Phil Turmel, Linux-RAID
In-Reply-To: <74e5712f-e89e-97af-8aa4-ae2948c02e94@turmel.org>
On 09/26/2016 04:15 PM, Phil Turmel wrote:
> On 09/26/2016 03:47 PM, Benjammin2068 wrote:
>> Well that instills fear and doubt...
>>
>> the mismatch_cnt was 8.
>>
>> I did a repair and then a check and now it's 10704....
>>
>> :(
> Danger Will Robinson!
>
> Seriously. You very likely have a hardware problem corrupting your
> data. Do you have ECC RAM, and if not, when was the last time you did
> an exhaustive memtest?
ECC RAM: Yes.
MEMtest - not for a while. Will do. Have to take my server down for that.
This problem has only popped up since putting in this new controller *AND* expanding the RAID to a drive on this controller when changing RAID5 with 4 members (using MB SATA ports) to RAID6 using 5 members that includes 2 drives on new controller of which 1 is a hot spare.
(and the controller is a Marvell 88SE9485 - anyone know of any problems with this controller? It's a x8 controller living in a x8 slot.
> Recheck all of your data cables and if using an add-on controller, check
> for a secure install in the PCIe slot.
>
Will do.
Is there way to verify if that 5th drive is "the problem drive"?
Also, I just did a "repair" and the mismatch is now back to 8... which seems like a suspicious number considering the filesystem on this new drive (because it's a WD10 series with 4096byte sectors) has a slightly larger FS than the Samsung HD103SJ (and Seagate equivalents) in the array too.
And I just found this:
https://www.thomas-krenn.com/en/wiki/Mdadm_checkarray
Which says, "It could simply be that the system does not care what is stored on that part of the array - it is unused space."
I have WD10 drives that have this "extra space" thing going on because of their 4096byte sector size thing. (see previous posts about that to this list.)
-Ben
^ permalink raw reply
* [PATCH v2 6/6] md/r5cache: decrease the counter after full-write stripe was reclaimed
From: Song Liu @ 2016-09-26 23:30 UTC (permalink / raw)
To: linux-raid
Cc: neilb, shli, kernel-team, dan.j.williams, hch, liuzhengyuang521,
liuzhengyuan, Song Liu
In-Reply-To: <20160926233050.3351081-1-songliubraving@fb.com>
From: ZhengYuan Liu <liuzhengyuan@kylinos.cn>
Once the data was written to cache device, r5c_handle_cached_data_endio would
be called to set dev->written with null and return the bio to up layer. As a
result, handle_stripe_clean_event has no chance to be called to decrease the
counter of conf->pending_full_writes when the stripe was written to raid disks
at reclaim stage. It should test the STRIPE_FULL_WRITE state and decrease the
counter at somewhere when the full-write stripe was reclaimed,
r5c_handle_stripe_written may be the right place to do that.
Signed-off-by: ZhengYuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Song Liu <songliubraving@fb.com>
---
drivers/md/raid5-cache.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index a94585d..8a035da 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -2044,6 +2044,10 @@ void r5c_handle_stripe_written(struct r5conf *conf,
spin_unlock_irqrestore(&conf->log->stripe_in_cache_lock, flags);
sh->log_start = MaxSector;
clear_bit(STRIPE_R5C_PRIORITY, &sh->state);
+
+ if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
+ if (atomic_dec_and_test(&conf->pending_full_writes))
+ md_wakeup_thread(conf->mddev->thread);
}
if (do_wakeup)
--
2.9.3
^ permalink raw reply related
* [PATCH v2 5/6] r5cache: handle SYNC and FUA
From: Song Liu @ 2016-09-26 23:30 UTC (permalink / raw)
To: linux-raid
Cc: neilb, shli, kernel-team, dan.j.williams, hch, liuzhengyuang521,
liuzhengyuan, Song Liu
In-Reply-To: <20160926233050.3351081-1-songliubraving@fb.com>
With raid5 cache, we committing data from journal device. When
there is flush request, we need to flush journal device's cache.
This was not needed in raid5 journal, because we will flush the
journal before committing data to raid disks.
This is similar to FUA, except that we also need flush journal for
FUA. Otherwise, corruptions in earlier meta data will stop recovery
from reaching FUA data.
Signed-off-by: Song Liu <songliubraving@fb.com>
---
drivers/md/raid5-cache.c | 134 +++++++++++++++++++++++++++++++++++++++++++----
drivers/md/raid5.c | 8 +++
drivers/md/raid5.h | 1 +
3 files changed, 133 insertions(+), 10 deletions(-)
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index eff5bad..a94585d 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -19,6 +19,7 @@
#include <linux/raid/md_p.h>
#include <linux/crc32c.h>
#include <linux/random.h>
+#include <trace/events/block.h>
#include "md.h"
#include "raid5.h"
@@ -119,6 +120,9 @@ struct r5l_log {
struct list_head stripe_in_cache; /* all stripes in the cache, with
* sh->log_start in order */
spinlock_t stripe_in_cache_lock; /* lock for stripe_in_cache */
+
+ /* to submit async io_units, to fulfill ordering of flush */
+ struct work_struct deferred_io_work;
};
/*
@@ -145,6 +149,18 @@ struct r5l_io_unit {
int state;
bool need_split_bio;
+ struct bio *split_bio;
+
+ unsigned int has_flush:1; /* include flush request */
+ unsigned int has_fua:1; /* include fua request */
+ unsigned int has_null_flush:1; /* include empty flush request */
+ /*
+ * io isn't sent yet, flush/fua request can only be submitted till it's
+ * the first IO in running_ios list
+ */
+ unsigned int io_deferred:1;
+
+ struct bio_list flush_barriers; /* size == 0 flush bios */
};
/* r5l_io_unit state */
@@ -358,9 +374,11 @@ static void r5l_move_to_end_ios(struct r5l_log *log)
}
}
+static void __r5l_stripe_write_finished(struct r5l_io_unit *io);
static void r5l_log_endio(struct bio *bio)
{
struct r5l_io_unit *io = bio->bi_private;
+ struct r5l_io_unit *io_deferred;
struct r5l_log *log = io->log;
unsigned long flags;
@@ -376,18 +394,89 @@ static void r5l_log_endio(struct bio *bio)
r5l_move_to_end_ios(log);
else
r5l_log_run_stripes(log);
+ if (!list_empty(&log->running_ios)) {
+ /*
+ * FLUSH/FUA io_unit is deferred because of ordering, now we
+ * can dispatch it
+ */
+ io_deferred = list_first_entry(&log->running_ios,
+ struct r5l_io_unit, log_sibling);
+ if (io_deferred->io_deferred)
+ schedule_work(&log->deferred_io_work);
+ }
+
spin_unlock_irqrestore(&log->io_list_lock, flags);
if (log->need_cache_flush)
md_wakeup_thread(log->rdev->mddev->thread);
+
+ if (io->has_null_flush) {
+ struct bio *bi;
+
+ WARN_ON(bio_list_empty(&io->flush_barriers));
+ while ((bi = bio_list_pop(&io->flush_barriers)) != NULL) {
+ bio_endio(bi);
+ atomic_dec(&io->pending_stripe);
+ }
+ if (atomic_read(&io->pending_stripe) == 0)
+ __r5l_stripe_write_finished(io);
+ }
+}
+
+static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&log->io_list_lock, flags);
+ __r5l_set_io_unit_state(io, IO_UNIT_IO_START);
+ spin_unlock_irqrestore(&log->io_list_lock, flags);
+
+ if (io->has_flush)
+ bio_set_op_attrs(io->current_bio, REQ_OP_WRITE, WRITE_FLUSH);
+ if (io->has_fua)
+ bio_set_op_attrs(io->current_bio, REQ_OP_WRITE, WRITE_FUA);
+ submit_bio(io->current_bio);
+
+ if (!io->split_bio)
+ return;
+
+ if (io->has_flush)
+ bio_set_op_attrs(io->split_bio, REQ_OP_WRITE, WRITE_FLUSH);
+ if (io->has_fua)
+ bio_set_op_attrs(io->split_bio, REQ_OP_WRITE, WRITE_FUA);
+ submit_bio(io->split_bio);
+}
+
+/* deferred io_unit will be dispatched here */
+static void r5l_submit_io_async(struct work_struct *work)
+{
+ struct r5l_log *log = container_of(work, struct r5l_log,
+ deferred_io_work);
+ struct r5l_io_unit *io = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&log->io_list_lock, flags);
+ if (!list_empty(&log->running_ios)) {
+ io = list_first_entry(&log->running_ios, struct r5l_io_unit,
+ log_sibling);
+ if (!io->io_deferred)
+ io = NULL;
+ else
+ io->io_deferred = 0;
+ }
+ spin_unlock_irqrestore(&log->io_list_lock, flags);
+ if (io)
+ r5l_do_submit_io(log, io);
}
static void r5l_submit_current_io(struct r5l_log *log)
{
struct r5l_io_unit *io = log->current_io;
+ struct bio *bio;
struct r5l_meta_block *block;
unsigned long flags;
u32 crc;
+ bool do_submit = true;
if (!io)
return;
@@ -396,13 +485,20 @@ static void r5l_submit_current_io(struct r5l_log *log)
block->meta_size = cpu_to_le32(io->meta_offset);
crc = crc32c_le(log->uuid_checksum, block, PAGE_SIZE);
block->checksum = cpu_to_le32(crc);
+ bio = io->current_bio;
log->current_io = NULL;
spin_lock_irqsave(&log->io_list_lock, flags);
- __r5l_set_io_unit_state(io, IO_UNIT_IO_START);
+ if (io->has_flush || io->has_fua) {
+ if (io != list_first_entry(&log->running_ios,
+ struct r5l_io_unit, log_sibling)) {
+ io->io_deferred = 1;
+ do_submit = false;
+ }
+ }
spin_unlock_irqrestore(&log->io_list_lock, flags);
-
- submit_bio(io->current_bio);
+ if (do_submit)
+ r5l_do_submit_io(log, io);
}
static struct bio *r5l_bio_alloc(struct r5l_log *log)
@@ -449,6 +545,7 @@ static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log)
io->log = log;
INIT_LIST_HEAD(&io->log_sibling);
INIT_LIST_HEAD(&io->stripe_list);
+ bio_list_init(&io->flush_barriers);
io->state = IO_UNIT_RUNNING;
io->meta_page = mempool_alloc(log->meta_pool, GFP_NOIO);
@@ -519,12 +616,11 @@ static void r5l_append_payload_page(struct r5l_log *log, struct page *page)
struct r5l_io_unit *io = log->current_io;
if (io->need_split_bio) {
- struct bio *prev = io->current_bio;
-
+ BUG_ON(io->split_bio);
+ io->split_bio = io->current_bio;
io->current_bio = r5l_bio_alloc(log);
- bio_chain(io->current_bio, prev);
-
- submit_bio(prev);
+ bio_chain(io->current_bio, io->split_bio);
+ io->need_split_bio = false;
}
if (!bio_add_page(io->current_bio, page, PAGE_SIZE, 0))
@@ -554,12 +650,22 @@ static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
io = log->current_io;
+ if (test_and_clear_bit(STRIPE_R5C_PREFLUSH, &sh->state))
+ io->has_flush = 1;
+
for (i = 0; i < sh->disks; i++) {
if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) &&
!test_bit(R5_Wantcache, &sh->dev[i].flags))
continue;
if (i == sh->pd_idx || i == sh->qd_idx)
continue;
+ if (test_bit(R5_WantFUA, &sh->dev[i].flags)) {
+ io->has_fua = 1;
+ /* we need to flush journal to make sure recovery can
+ * reach the data with fua flag
+ */
+ io->has_flush = 1;
+ }
r5l_append_payload_meta(log, R5LOG_PAYLOAD_DATA,
raid5_compute_blocknr(sh, i, 0),
sh->dev[i].log_checksum, 0, false);
@@ -716,10 +822,16 @@ int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
* don't need to flush again
*/
if (bio->bi_iter.bi_size == 0) {
- bio_endio(bio);
+ mutex_lock(&log->io_mutex);
+ r5l_get_meta(log, 0);
+ bio_list_add(&log->current_io->flush_barriers, bio);
+ log->current_io->has_flush = 1;
+ log->current_io->has_null_flush = 1;
+ atomic_inc(&log->current_io->pending_stripe);
+ r5l_submit_current_io(log);
+ mutex_unlock(&log->io_mutex);
return 0;
}
- bio->bi_opf &= ~REQ_PREFLUSH;
return -EAGAIN;
}
@@ -2186,6 +2298,8 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
INIT_LIST_HEAD(&log->no_space_stripes);
spin_lock_init(&log->no_space_stripes_lock);
+ INIT_WORK(&log->deferred_io_work, r5l_submit_io_async);
+
/* flush full stripe */
log->r5c_state = R5C_STATE_WRITE_BACK;
INIT_LIST_HEAD(&log->stripe_in_cache);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index a3d26ec..df31bfa 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5321,6 +5321,7 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
int remaining;
DEFINE_WAIT(w);
bool do_prepare;
+ bool do_flush = false;
if (unlikely(bi->bi_opf & REQ_PREFLUSH)) {
int ret = r5l_handle_flush_request(conf->log, bi);
@@ -5332,6 +5333,7 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
return;
}
/* ret == -EAGAIN, fallback */
+ do_flush = true;
}
md_write_start(mddev, bi);
@@ -5470,6 +5472,12 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
do_prepare = true;
goto retry;
}
+ if (do_flush) {
+ set_bit(STRIPE_R5C_PREFLUSH, &sh->state);
+ /* we only need flush for one stripe */
+ do_flush = false;
+ }
+
set_bit(STRIPE_HANDLE, &sh->state);
clear_bit(STRIPE_DELAYED, &sh->state);
if ((!sh->batch_head || sh == sh->batch_head) &&
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 2d8222c..bbb2536 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -359,6 +359,7 @@ enum {
STRIPE_R5C_FROZEN, /* r5c_cache frozen and being written out */
STRIPE_R5C_WRITTEN, /* ready for r5c_handle_stripe_written() */
STRIPE_R5C_PRIORITY, /* high priority stripe for log reclaim */
+ STRIPE_R5C_PREFLUSH, /* need to flush journal device */
};
#define STRIPE_EXPAND_SYNC_FLAGS \
--
2.9.3
^ permalink raw reply related
* [PATCH v2 4/6] r5cache: r5c recovery
From: Song Liu @ 2016-09-26 23:30 UTC (permalink / raw)
To: linux-raid
Cc: neilb, shli, kernel-team, dan.j.williams, hch, liuzhengyuang521,
liuzhengyuan, Song Liu
In-Reply-To: <20160926233050.3351081-1-songliubraving@fb.com>
This is the recovery part of raid5-cache.
With cache feature, there are 2 different scenarios of recovery:
1. Data-Parity stripe: a stripe with complete parity in journal.
2. Data-Only stripe: a stripe with only data in journal (or partial
parity).
The code differentiate Data-Parity stripe from Data-Only stripe with
flag (STRIPE_R5C_WRITTEN).
For Data-Parity stripes, we use the same procedure as raid5 journal,
where all the data and parity are replayed to the RAID devices.
For Data-Only strips, we need to finish complete calculate parity and
finish the full reconstruct write or RMW write. For simplicity, in
the recovery, we load the stripe to stripe cache. Once the array is
started, the stripe cache state machine will handle these stripes
through normal write path.
r5c_recovery_flush_log contains the main procedure of recovery. The
recovery code first scans through the journal and loads data to
stripe cache. The code keeps tracks of all these stripes in a list
(use sh->lru and ctx->cached_list), stripes in the list are
organized in the order of its first appearance on the journal.
During the scan, the recovery code assesses each stripe as
Data-Parity or Data-Only.
During scan, the array may run out of stripe cache. In these cases,
the recovery code tries to release some stripe head by replaying
existing Data-Parity stripes. Once these replays are done, these
stripes can be released. When releasing Data-Parity stripes is not
enough, the recovery code will also call raid5_set_cache_size to
increase stripe cache size.
At the end of scan, the recovery code replays all Data-Parity
stripes, and sets proper states for Data-Only stripes. The recovery
code also increases seq number by 10 and rewrites all Data-Only
stripes to journal. This is to avoid confusion after repeated
crashes. More details is explained in raid5-cache.c before
r5c_recovery_rewrite_data_only_stripes().
Signed-off-by: Song Liu <songliubraving@fb.com>
---
drivers/md/raid5-cache.c | 681 +++++++++++++++++++++++++++++++++++++----------
1 file changed, 547 insertions(+), 134 deletions(-)
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 75b70d8..eff5bad 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -1,5 +1,6 @@
/*
* Copyright (C) 2015 Shaohua Li <shli@fb.com>
+ * Copyright (C) 2016 Song Liu <songliubraving@fb.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
@@ -1072,10 +1073,13 @@ struct r5l_recovery_ctx {
sector_t meta_total_blocks; /* total size of current meta and data */
sector_t pos; /* recovery position */
u64 seq; /* recovery position seq */
+ int data_parity_stripes; /* number of data_parity stripes */
+ int data_only_stripes; /* number of data_only stripes */
+ struct list_head cached_list;
};
-static int r5l_read_meta_block(struct r5l_log *log,
- struct r5l_recovery_ctx *ctx)
+static int r5l_recovery_read_meta_block(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx)
{
struct page *page = ctx->meta_page;
struct r5l_meta_block *mb;
@@ -1107,170 +1111,577 @@ static int r5l_read_meta_block(struct r5l_log *log,
return 0;
}
-static int r5l_recovery_flush_one_stripe(struct r5l_log *log,
- struct r5l_recovery_ctx *ctx,
- sector_t stripe_sect,
- int *offset, sector_t *log_offset)
+/*
+ * r5l_recovery_load_data and r5l_recovery_load_parity uses flag R5_Wantwrite
+ * to mark valid (potentially not flushed) data in the journal.
+ *
+ * We already verified checksum in r5l_recovery_verify_data_checksum_for_mb,
+ * so there should not be any mismatch here.
+ */
+static void r5l_recovery_load_data(struct r5l_log *log,
+ struct stripe_head *sh,
+ struct r5l_recovery_ctx *ctx,
+ struct r5l_payload_data_parity *payload,
+ sector_t log_offset)
{
- struct r5conf *conf = log->rdev->mddev->private;
- struct stripe_head *sh;
- struct r5l_payload_data_parity *payload;
+ struct mddev *mddev = log->rdev->mddev;
+ struct r5conf *conf = mddev->private;
int disk_index;
- sh = raid5_get_active_stripe(conf, stripe_sect, 0, 0, 0);
- while (1) {
- payload = page_address(ctx->meta_page) + *offset;
+ raid5_compute_sector(conf,
+ le64_to_cpu(payload->location), 0,
+ &disk_index, sh);
+ sync_page_io(log->rdev, log_offset, PAGE_SIZE,
+ sh->dev[disk_index].page, REQ_OP_READ, 0, false);
+ sh->dev[disk_index].log_checksum =
+ le32_to_cpu(payload->checksum[0]);
+ ctx->meta_total_blocks += BLOCK_SECTORS;
- if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
- raid5_compute_sector(conf,
- le64_to_cpu(payload->location), 0,
- &disk_index, sh);
+ set_bit(R5_Wantwrite, &sh->dev[disk_index].flags);
+}
- sync_page_io(log->rdev, *log_offset, PAGE_SIZE,
- sh->dev[disk_index].page, REQ_OP_READ, 0,
- false);
- sh->dev[disk_index].log_checksum =
- le32_to_cpu(payload->checksum[0]);
- set_bit(R5_Wantwrite, &sh->dev[disk_index].flags);
- ctx->meta_total_blocks += BLOCK_SECTORS;
- } else {
- disk_index = sh->pd_idx;
- sync_page_io(log->rdev, *log_offset, PAGE_SIZE,
- sh->dev[disk_index].page, REQ_OP_READ, 0,
- false);
- sh->dev[disk_index].log_checksum =
- le32_to_cpu(payload->checksum[0]);
- set_bit(R5_Wantwrite, &sh->dev[disk_index].flags);
-
- if (sh->qd_idx >= 0) {
- disk_index = sh->qd_idx;
- sync_page_io(log->rdev,
- r5l_ring_add(log, *log_offset, BLOCK_SECTORS),
- PAGE_SIZE, sh->dev[disk_index].page,
- REQ_OP_READ, 0, false);
- sh->dev[disk_index].log_checksum =
- le32_to_cpu(payload->checksum[1]);
- set_bit(R5_Wantwrite,
- &sh->dev[disk_index].flags);
- }
- ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
- }
+static void r5l_recovery_load_parity(struct r5l_log *log,
+ struct stripe_head *sh,
+ struct r5l_recovery_ctx *ctx,
+ struct r5l_payload_data_parity *payload,
+ sector_t log_offset)
+{
+ struct mddev *mddev = log->rdev->mddev;
+ struct r5conf *conf = mddev->private;
- *log_offset = r5l_ring_add(log, *log_offset,
- le32_to_cpu(payload->size));
- *offset += sizeof(struct r5l_payload_data_parity) +
- sizeof(__le32) *
- (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
- if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY)
- break;
+ ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
+ sync_page_io(log->rdev, log_offset, PAGE_SIZE,
+ sh->dev[sh->pd_idx].page, REQ_OP_READ, 0, false);
+ sh->dev[sh->pd_idx].log_checksum =
+ le32_to_cpu(payload->checksum[0]);
+ set_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags);
+
+ if (sh->qd_idx >= 0) {
+ sync_page_io(log->rdev,
+ r5l_ring_add(log, log_offset, BLOCK_SECTORS),
+ PAGE_SIZE, sh->dev[sh->qd_idx].page,
+ REQ_OP_READ, 0, false);
+ sh->dev[sh->qd_idx].log_checksum =
+ le32_to_cpu(payload->checksum[1]);
+ set_bit(R5_Wantwrite, &sh->dev[sh->qd_idx].flags);
}
+ set_bit(STRIPE_R5C_WRITTEN, &sh->state);
+}
- for (disk_index = 0; disk_index < sh->disks; disk_index++) {
- void *addr;
- u32 checksum;
+static void r5l_recovery_reset_stripe(struct stripe_head *sh)
+{
+ int i;
+
+ sh->state = 0;
+ sh->log_start = MaxSector;
+ for (i = sh->disks; i--; )
+ sh->dev[i].flags = 0;
+}
+
+static void
+r5l_recovery_replay_one_stripe(struct r5conf *conf,
+ struct stripe_head *sh,
+ struct r5l_recovery_ctx *ctx)
+{
+ struct md_rdev *rdev, *rrdev;
+ int disk_index;
+ int data_count = 0;
+ for (disk_index = 0; disk_index < sh->disks; disk_index++) {
if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
continue;
- addr = kmap_atomic(sh->dev[disk_index].page);
- checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
- kunmap_atomic(addr);
- if (checksum != sh->dev[disk_index].log_checksum)
- goto error;
+ if (disk_index == sh->qd_idx || disk_index == sh->pd_idx)
+ continue;
+ data_count++;
}
+ /* stripes only have parity are already flushed to RAID */
+ if (data_count == 0)
+ goto out;
for (disk_index = 0; disk_index < sh->disks; disk_index++) {
- struct md_rdev *rdev, *rrdev;
-
- if (!test_and_clear_bit(R5_Wantwrite,
- &sh->dev[disk_index].flags))
+ if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
continue;
/* in case device is broken */
rdev = rcu_dereference(conf->disks[disk_index].rdev);
if (rdev)
- sync_page_io(rdev, stripe_sect, PAGE_SIZE,
+ sync_page_io(rdev, sh->sector, PAGE_SIZE,
sh->dev[disk_index].page, REQ_OP_WRITE, 0,
false);
rrdev = rcu_dereference(conf->disks[disk_index].replacement);
if (rrdev)
- sync_page_io(rrdev, stripe_sect, PAGE_SIZE,
+ sync_page_io(rrdev, sh->sector, PAGE_SIZE,
sh->dev[disk_index].page, REQ_OP_WRITE, 0,
false);
}
- raid5_release_stripe(sh);
+ ctx->data_parity_stripes++;
+out:
+ r5l_recovery_reset_stripe(sh);
+}
+
+static void
+r5l_recovery_create_emtpy_meta_block(struct r5l_log *log,
+ struct page *page,
+ sector_t pos, u64 seq)
+{
+ struct r5l_meta_block *mb;
+ u32 crc;
+
+ mb = page_address(page);
+ clear_page(mb);
+ mb->magic = cpu_to_le32(R5LOG_MAGIC);
+ mb->version = R5LOG_VERSION;
+ mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
+ mb->seq = cpu_to_le64(seq);
+ mb->position = cpu_to_le64(pos);
+ crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
+ mb->checksum = cpu_to_le32(crc);
+}
+
+static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
+ u64 seq)
+{
+ struct page *page;
+
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+ r5l_recovery_create_emtpy_meta_block(log, page, pos, seq);
+ if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE,
+ WRITE_FUA, false)) {
+ __free_page(page);
+ return -EIO;
+ }
+ __free_page(page);
return 0;
+}
-error:
- for (disk_index = 0; disk_index < sh->disks; disk_index++)
- sh->dev[disk_index].flags = 0;
- raid5_release_stripe(sh);
- return -EINVAL;
+static struct stripe_head *
+r5c_recovery_alloc_stripe(struct r5conf *conf,
+ struct list_head *recovery_list,
+ sector_t stripe_sect,
+ sector_t log_start)
+{
+ struct stripe_head *sh;
+
+ sh = raid5_get_active_stripe(conf, stripe_sect, 0, 1, 0);
+ if (!sh)
+ return NULL; /* no more stripe available */
+
+ r5l_recovery_reset_stripe(sh);
+ sh->log_start = log_start;
+
+ return sh;
}
-static int r5l_recovery_flush_one_meta(struct r5l_log *log,
- struct r5l_recovery_ctx *ctx)
+static struct stripe_head *
+r5c_recovery_lookup_stripe(struct list_head *list, sector_t sect)
{
- struct r5conf *conf = log->rdev->mddev->private;
+ struct stripe_head *sh;
+
+ list_for_each_entry(sh, list, lru)
+ if (sh->sector == sect)
+ return sh;
+ return NULL;
+}
+
+static void
+r5c_recovery_replay_stripes(struct list_head *cached_stripe_list,
+ struct r5l_recovery_ctx *ctx)
+{
+ struct stripe_head *sh, *next;
+
+ list_for_each_entry_safe(sh, next, cached_stripe_list, lru)
+ if (test_bit(STRIPE_R5C_WRITTEN, &sh->state)) {
+ r5l_recovery_replay_one_stripe(sh->raid_conf, sh, ctx);
+ list_del_init(&sh->lru);
+ raid5_release_stripe(sh);
+ }
+}
+
+/* returns 0 for match; 1 for mismtach */
+static int
+r5l_recovery_verify_data_checksum(struct r5l_log *log, struct page *page,
+ sector_t log_offset, __le32 log_checksum)
+{
+ void *addr;
+ u32 checksum;
+
+ sync_page_io(log->rdev, log_offset, PAGE_SIZE,
+ page, REQ_OP_READ, 0, false);
+ addr = kmap_atomic(page);
+ checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
+ kunmap_atomic(addr);
+ return le32_to_cpu(log_checksum) != checksum;
+}
+
+/*
+ * before loading data to stripe cache, we need verify checksum for all data,
+ * if there is mismatch for any data page, we drop all data in the mata block
+ */
+static int
+r5l_recovery_verify_data_checksum_for_mb(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx)
+{
+ struct mddev *mddev = log->rdev->mddev;
+ struct r5conf *conf = mddev->private;
+ struct r5l_meta_block *mb = page_address(ctx->meta_page);
+ sector_t mb_offset = sizeof(struct r5l_meta_block);
+ sector_t log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
+ struct page *page;
struct r5l_payload_data_parity *payload;
+
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ while (mb_offset < le32_to_cpu(mb->meta_size)) {
+ payload = (void *)mb + mb_offset;
+
+ if (payload->header.type == R5LOG_PAYLOAD_DATA) {
+ if (r5l_recovery_verify_data_checksum(
+ log, page, log_offset,
+ payload->checksum[0]))
+ goto mismatch;
+ } else if (payload->header.type == R5LOG_PAYLOAD_PARITY) {
+ if (r5l_recovery_verify_data_checksum(
+ log, page, log_offset,
+ payload->checksum[0]))
+ goto mismatch;
+ if (conf->max_degraded == 2 && /* q for RAID 6 */
+ r5l_recovery_verify_data_checksum(
+ log, page,
+ r5l_ring_add(log, log_offset,
+ BLOCK_SECTORS),
+ payload->checksum[1]))
+ goto mismatch;
+ } else
+ goto mismatch;
+
+ log_offset = r5l_ring_add(log, log_offset,
+ le32_to_cpu(payload->size));
+
+ mb_offset += sizeof(struct r5l_payload_data_parity) +
+ sizeof(__le32) *
+ (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
+ }
+
+ put_page(page);
+ return 0;
+
+mismatch:
+ put_page(page);
+ return -EINVAL;
+}
+
+static int
+r5c_recovery_analyze_meta_block(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx,
+ struct list_head *cached_stripe_list)
+{
+ struct mddev *mddev = log->rdev->mddev;
+ struct r5conf *conf = mddev->private;
struct r5l_meta_block *mb;
- int offset;
+ struct r5l_payload_data_parity *payload;
+ int mb_offset;
sector_t log_offset;
- sector_t stripe_sector;
+ sector_t stripe_sect;
+ struct stripe_head *sh;
+ int ret;
+
+ /* for mismatch in data blocks, we will drop all data in this mb, but
+ * we will still read next mb for other data with FLUSH flag, as
+ * io_unit could finish out of order.
+ */
+ ret = r5l_recovery_verify_data_checksum_for_mb(log, ctx);
+ if (ret == -EINVAL)
+ return -EAGAIN;
+ else if (ret)
+ return ret;
mb = page_address(ctx->meta_page);
- offset = sizeof(struct r5l_meta_block);
+ mb_offset = sizeof(struct r5l_meta_block);
log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
- while (offset < le32_to_cpu(mb->meta_size)) {
+ while (mb_offset < le32_to_cpu(mb->meta_size)) {
int dd;
- payload = (void *)mb + offset;
- stripe_sector = raid5_compute_sector(conf,
- le64_to_cpu(payload->location), 0, &dd, NULL);
- if (r5l_recovery_flush_one_stripe(log, ctx, stripe_sector,
- &offset, &log_offset))
+ payload = (void *)mb + mb_offset;
+ stripe_sect = (payload->header.type == R5LOG_PAYLOAD_DATA) ?
+ raid5_compute_sector(
+ conf, le64_to_cpu(payload->location), 0, &dd,
+ NULL)
+ : le64_to_cpu(payload->location);
+
+ sh = r5c_recovery_lookup_stripe(cached_stripe_list,
+ stripe_sect);
+
+ if (!sh) {
+ sh = r5c_recovery_alloc_stripe(conf, cached_stripe_list,
+ stripe_sect, ctx->pos);
+ /* cannot get stripe from raid5_get_active_stripe
+ * try replay some stripes
+ */
+ if (!sh) {
+ r5c_recovery_replay_stripes(
+ cached_stripe_list, ctx);
+ sh = r5c_recovery_alloc_stripe(
+ conf, cached_stripe_list,
+ stripe_sect, ctx->pos);
+ }
+ if (!sh) {
+ pr_info("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n",
+ mdname(mddev),
+ conf->min_nr_stripes * 2);
+ raid5_set_cache_size(mddev,
+ conf->min_nr_stripes * 2);
+ sh = r5c_recovery_alloc_stripe(
+ conf, cached_stripe_list, stripe_sect,
+ ctx->pos);
+ }
+ if (!sh) {
+ pr_err("md/raid:%s: Cannot get enough stripe_cache. Recovery interrupted.\n",
+ mdname(mddev));
+ return -ENOMEM;
+ }
+ list_add_tail(&sh->lru, cached_stripe_list);
+ }
+ if (!sh)
+ return -ENOMEM;
+
+ if (payload->header.type == R5LOG_PAYLOAD_DATA) {
+ if (test_bit(STRIPE_R5C_WRITTEN, &sh->state)) {
+ r5l_recovery_reset_stripe(sh);
+ sh->log_start = ctx->pos;
+ list_move_tail(&sh->lru, cached_stripe_list);
+ }
+ r5l_recovery_load_data(log, sh, ctx, payload,
+ log_offset);
+ } else if (payload->header.type == R5LOG_PAYLOAD_PARITY)
+ r5l_recovery_load_parity(log, sh, ctx, payload,
+ log_offset);
+ else
return -EINVAL;
+
+ log_offset = r5l_ring_add(log, log_offset,
+ le32_to_cpu(payload->size));
+
+ mb_offset += sizeof(struct r5l_payload_data_parity) +
+ sizeof(__le32) *
+ (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
}
+
return 0;
}
-/* copy data/parity from log to raid disks */
-static void r5l_recovery_flush_log(struct r5l_log *log,
+/*
+ * Load the stripe into cache. The stripe will be written out later by
+ * the stripe cache state machine.
+ */
+static void r5c_recovery_load_one_stripe(struct r5l_log *log,
+ struct stripe_head *sh)
+{
+ struct r5conf *conf = sh->raid_conf;
+ struct r5dev *dev;
+ int i;
+
+ atomic_set(&sh->dev_in_cache, 0);
+ for (i = sh->disks; i--; ) {
+ dev = sh->dev + i;
+ if (test_and_clear_bit(R5_Wantwrite, &dev->flags)) {
+ set_bit(R5_InCache, &dev->flags);
+ atomic_inc(&sh->dev_in_cache);
+ }
+ }
+ set_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state);
+ atomic_inc(&conf->r5c_cached_partial_stripes);
+ list_add_tail(&sh->r5c, &log->stripe_in_cache);
+}
+
+/*
+ * Scan through the log for all to-be-flushed data
+ *
+ * For stripes with data and parity, namely Data-Parity stripe
+ * (STRIPE_R5C_WRITTEN == 0), we simply replay all the writes.
+ *
+ * For stripes with only data, namely Data-Only stripe
+ * (STRIPE_R5C_WRITTEN == 1), we load them to stripe cache state machine.
+ *
+ * For a stripe, if we see data after parity, we should discard all previous
+ * data and parity for this stripe, as these data are already flushed to
+ * the array.
+ *
+ * At the end of the scan, we return the new journal_tail, which points to
+ * first data-only stripe on the journal device, or next invalid meta block.
+ */
+static void r5c_recovery_flush_log(struct r5l_log *log,
struct r5l_recovery_ctx *ctx)
{
+ struct stripe_head *sh, *next;
+ int ret;
+
+ /* scan through the log */
while (1) {
- if (r5l_read_meta_block(log, ctx))
- return;
- if (r5l_recovery_flush_one_meta(log, ctx))
- return;
+ if (r5l_recovery_read_meta_block(log, ctx))
+ break;
+
+ ret = r5c_recovery_analyze_meta_block(log, ctx,
+ &ctx->cached_list);
+ /* -EAGAIN means mismatch in data block, in this case, we still
+ * try scan the next metablock
+ */
+ if (ret && ret != -EAGAIN)
+ break;
ctx->seq++;
ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks);
}
+
+ /* replay data-parity stripes */
+ r5c_recovery_replay_stripes(&ctx->cached_list, ctx);
+
+ /* load data-only stripes to stripe cache */
+ list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
+ WARN_ON(test_bit(STRIPE_R5C_WRITTEN, &sh->state));
+ r5c_recovery_load_one_stripe(log, sh);
+ list_del_init(&sh->lru);
+ raid5_release_stripe(sh);
+ ctx->data_only_stripes++;
+ }
+
+ return;
}
-static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
- u64 seq)
+/*
+ * we did a recovery. Now ctx.pos points to an invalid meta block. New
+ * log will start here. but we can't let superblock point to last valid
+ * meta block. The log might looks like:
+ * | meta 1| meta 2| meta 3|
+ * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
+ * superblock points to meta 1, we write a new valid meta 2n. if crash
+ * happens again, new recovery will start from meta 1. Since meta 2n is
+ * valid now, recovery will think meta 3 is valid, which is wrong.
+ * The solution is we create a new meta in meta2 with its seq == meta
+ * 1's seq + 10 and let superblock points to meta2. The same recovery will
+ * not think meta 3 is a valid meta, because its seq doesn't match
+ */
+
+/*
+ * Before recovery, the log looks like the following
+ *
+ * ---------------------------------------------
+ * | valid log | invalid log |
+ * ---------------------------------------------
+ * ^
+ * |- log->last_checkpoint
+ * |- log->last_cp_seq
+ *
+ * Now we scan through the log until we see invalid entry
+ *
+ * ---------------------------------------------
+ * | valid log | invalid log |
+ * ---------------------------------------------
+ * ^ ^
+ * |- log->last_checkpoint |- ctx->pos
+ * |- log->last_cp_seq |- ctx->seq
+ *
+ * From this point, we need to increase seq number by 10 to avoid
+ * confusing next recovery.
+ *
+ * ---------------------------------------------
+ * | valid log | invalid log |
+ * ---------------------------------------------
+ * ^ ^
+ * |- log->last_checkpoint |- ctx->pos+1
+ * |- log->last_cp_seq |- ctx->seq+11
+ *
+ * However, it is not safe to start the state machine yet, because data only
+ * parities are not yet secured in RAID. To save these data only parities, we
+ * rewrite them from seq+11.
+ *
+ * -----------------------------------------------------------------
+ * | valid log | data only stripes | invalid log |
+ * -----------------------------------------------------------------
+ * ^ ^
+ * |- log->last_checkpoint |- ctx->pos+n
+ * |- log->last_cp_seq |- ctx->seq+10+n
+ *
+ * If failure happens again during this process, the recovery can safe start
+ * again from log->last_checkpoint.
+ *
+ * Once data only stripes are rewritten to journal, we move log_tail
+ *
+ * -----------------------------------------------------------------
+ * | old log | data only stripes | invalid log |
+ * -----------------------------------------------------------------
+ * ^ ^
+ * |- log->last_checkpoint |- ctx->pos+n
+ * |- log->last_cp_seq |- ctx->seq+10+n
+ *
+ * Then we can safely start the state machine. If failure happens from this
+ * point on, the recovery will start from new log->last_checkpoint.
+ */
+static int
+r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx)
{
+ struct stripe_head *sh;
+ struct mddev *mddev = log->rdev->mddev;
struct page *page;
- struct r5l_meta_block *mb;
- u32 crc;
- page = alloc_page(GFP_KERNEL | __GFP_ZERO);
- if (!page)
+ page = alloc_page(GFP_KERNEL);
+ if (!page) {
+ pr_err("md/raid:%s: cannot allocate memory to rewrite data only stripes\n",
+ mdname(mddev));
return -ENOMEM;
- mb = page_address(page);
- mb->magic = cpu_to_le32(R5LOG_MAGIC);
- mb->version = R5LOG_VERSION;
- mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
- mb->seq = cpu_to_le64(seq);
- mb->position = cpu_to_le64(pos);
- crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
- mb->checksum = cpu_to_le32(crc);
+ }
- if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE,
- WRITE_FUA, false)) {
- __free_page(page);
- return -EIO;
+ ctx->seq += 10;
+ list_for_each_entry(sh, &ctx->cached_list, lru) {
+ struct r5l_meta_block *mb;
+ int i;
+ int offset;
+ sector_t write_pos;
+
+ WARN_ON(test_bit(STRIPE_R5C_WRITTEN, &sh->state));
+ r5l_recovery_create_emtpy_meta_block(log, page,
+ ctx->pos, ctx->seq);
+ mb = page_address(page);
+ offset = le32_to_cpu(mb->meta_size);
+ write_pos = ctx->pos + BLOCK_SECTORS;
+
+ for (i = sh->disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ struct r5l_payload_data_parity *payload;
+ void *addr;
+
+ if (test_bit(R5_InCache, &dev->flags)) {
+ payload = (void *)mb + offset;
+ payload->header.type = cpu_to_le16(
+ R5LOG_PAYLOAD_DATA);
+ payload->size = BLOCK_SECTORS;
+ payload->location = cpu_to_le64(
+ raid5_compute_blocknr(sh, i, 0));
+ addr = kmap_atomic(dev->page);
+ payload->checksum[0] = cpu_to_le32(
+ crc32c_le(log->uuid_checksum, addr,
+ PAGE_SIZE));
+ kunmap_atomic(addr);
+ sync_page_io(log->rdev, write_pos, PAGE_SIZE,
+ dev->page, REQ_OP_WRITE, 0, false);
+ write_pos = r5l_ring_add(log, write_pos,
+ BLOCK_SECTORS);
+ offset += sizeof(__le32) +
+ sizeof(struct r5l_payload_data_parity);
+
+ }
+ }
+ mb->meta_size = cpu_to_le32(offset);
+ mb->checksum = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
+ sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page,
+ REQ_OP_WRITE, WRITE_FUA, false);
+ sh->log_start = ctx->pos;
+ ctx->pos = write_pos;
+ ctx->seq += 1;
}
__free_page(page);
return 0;
@@ -1278,43 +1689,45 @@ static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
static int r5l_recovery_log(struct r5l_log *log)
{
+ struct mddev *mddev = log->rdev->mddev;
struct r5l_recovery_ctx ctx;
ctx.pos = log->last_checkpoint;
ctx.seq = log->last_cp_seq;
ctx.meta_page = alloc_page(GFP_KERNEL);
+ ctx.data_only_stripes = 0;
+ ctx.data_parity_stripes = 0;
+ INIT_LIST_HEAD(&ctx.cached_list);
+
if (!ctx.meta_page)
return -ENOMEM;
- r5l_recovery_flush_log(log, &ctx);
+ r5c_recovery_flush_log(log, &ctx);
+
__free_page(ctx.meta_page);
- /*
- * we did a recovery. Now ctx.pos points to an invalid meta block. New
- * log will start here. but we can't let superblock point to last valid
- * meta block. The log might looks like:
- * | meta 1| meta 2| meta 3|
- * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
- * superblock points to meta 1, we write a new valid meta 2n. if crash
- * happens again, new recovery will start from meta 1. Since meta 2n is
- * valid now, recovery will think meta 3 is valid, which is wrong.
- * The solution is we create a new meta in meta2 with its seq == meta
- * 1's seq + 10 and let superblock points to meta2. The same recovery will
- * not think meta 3 is a valid meta, because its seq doesn't match
- */
- if (ctx.seq > log->last_cp_seq + 1) {
- int ret;
-
- ret = r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq + 10);
- if (ret)
- return ret;
- log->seq = ctx.seq + 11;
- log->log_start = r5l_ring_add(log, ctx.pos, BLOCK_SECTORS);
- r5l_write_super(log, ctx.pos);
- } else {
- log->log_start = ctx.pos;
- log->seq = ctx.seq;
+ if ((ctx.data_only_stripes == 0) && (ctx.data_parity_stripes == 0))
+ pr_info("md/raid:%s: starting from clean shutdown\n",
+ mdname(mddev));
+ else {
+ pr_info("md/raid:%s: recoverying %d data-only stripes and %d data-parity stripes\n",
+ mdname(mddev), ctx.data_only_stripes,
+ ctx.data_parity_stripes);
+
+ if (ctx.data_only_stripes > 0)
+ if (r5c_recovery_rewrite_data_only_stripes(log, &ctx)) {
+ pr_err("md/raid:%s: failed to rewrite stripes to journal\n",
+ mdname(mddev));
+ return -EIO;
+ }
}
+
+ log->log_start = ctx.pos;
+ log->next_checkpoint = ctx.pos;
+ log->seq = ctx.seq;
+ r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq);
+ r5l_write_super(log, ctx.pos);
+
return 0;
}
--
2.9.3
^ permalink raw reply related
* [PATCH v2 3/6] r5cache: reclaim support
From: Song Liu @ 2016-09-26 23:30 UTC (permalink / raw)
To: linux-raid
Cc: neilb, shli, kernel-team, dan.j.williams, hch, liuzhengyuang521,
liuzhengyuan, Song Liu
In-Reply-To: <20160926233050.3351081-1-songliubraving@fb.com>
There are two limited resources, stripe cache and journal disk space.
For better performance, we priotize reclaim of full stripe writes.
To free up more journal space, we free earliest data on the journal.
In current implementation, reclaim happens when:
1. every R5C_RECLAIM_WAKEUP_INTERVAL (5 seconds)
2. when there are R5C_FULL_STRIPE_FLUSH_BATCH (8) cached full stripes
(r5c_check_cached_full_stripe)
3. when raid5_get_active_stripe sees pressure in stripe cache space
(r5c_check_stripe_cache_usage)
4. when there is pressure in journal space.
1-3 above are straightforward.
For 4, we added 2 flags to r5conf->cache_state: R5C_LOG_TIGHT and
R5C_LOG_CRITICAL. R5C_LOG_TIGHT is set when 2x max_free_space of
journal space is in-use; while R5C_LOG_CRITICAL is set when 3x
max_free_space of journal space is in-use. Where max_free_space
= min(1/4 journal space, 10GB).
r5c_cache keeps all data in cache (not fully committed to RAID) in
a list (stripe_in_cache). These stripes are in the order of their
first appearance on the journal. So the log tail (last_checkpoint)
should point to the journal_start of the first item in the list.
When R5C_LOG_TIGHT is set, r5l_reclaim_thread starts freezing
stripes at the head of stripe_in_cache. When R5C_LOG_CRITICAL is
set, the state machine only processes stripes at the head of
stripe_in_cache (other stripes are added to no_space_stripes in
r5c_cache_data and r5l_write_stripe).
Signed-off-by: Song Liu <songliubraving@fb.com>
---
drivers/md/raid5-cache.c | 313 +++++++++++++++++++++++++++++++++++++++--------
drivers/md/raid5.c | 31 +++--
drivers/md/raid5.h | 37 ++++--
3 files changed, 313 insertions(+), 68 deletions(-)
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 0a0b16a..75b70d8 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -28,8 +28,7 @@
#define BLOCK_SECTORS (8)
/*
- * reclaim runs every 1/4 disk size or 10G reclaimable space. This can prevent
- * recovery scans a very long log
+ * log->max_free_space is min(1/4 disk size, 10G reclaimable space)
*/
#define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */
#define RECLAIM_MAX_FREE_SPACE_SHIFT (2)
@@ -116,6 +115,9 @@ struct r5l_log {
/* for r5c_cache */
enum r5c_state r5c_state;
+ struct list_head stripe_in_cache; /* all stripes in the cache, with
+ * sh->log_start in order */
+ spinlock_t stripe_in_cache_lock; /* lock for stripe_in_cache */
};
/*
@@ -180,6 +182,16 @@ static bool r5l_has_free_space(struct r5l_log *log, sector_t size)
return log->device_size > used_size + size;
}
+static sector_t r5l_used_space(struct r5l_log *log)
+{
+ sector_t ret;
+
+ WARN_ON(!mutex_is_locked(&log->io_mutex));
+ ret = r5l_ring_distance(log, log->last_checkpoint,
+ log->log_start);
+ return ret;
+}
+
static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
enum r5l_io_unit_state state)
{
@@ -188,6 +200,56 @@ static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
io->state = state;
}
+static inline int r5c_total_cached_stripes(struct r5conf *conf)
+{
+ return atomic_read(&conf->r5c_cached_partial_stripes) +
+ atomic_read(&conf->r5c_cached_full_stripes);
+}
+
+/*
+ * check whether we should flush some stripes to free up stripe cache
+ */
+void r5c_check_stripe_cache_usage(struct r5conf *conf)
+{
+ if (!conf->log)
+ return;
+ spin_lock(&conf->device_lock);
+ if (r5c_total_cached_stripes(conf) > conf->max_nr_stripes * 3 / 4 ||
+ atomic_read(&conf->empty_inactive_list_nr) > 0)
+ r5c_flush_cache(conf, R5C_RECLAIM_STRIPE_GROUP);
+ else if (r5c_total_cached_stripes(conf) >
+ conf->max_nr_stripes * 1 / 2)
+ r5c_flush_cache(conf, 1);
+ spin_unlock(&conf->device_lock);
+}
+
+void r5c_check_cached_full_stripe(struct r5conf *conf)
+{
+ if (!conf->log)
+ return;
+ if (atomic_read(&conf->r5c_cached_full_stripes) >=
+ R5C_FULL_STRIPE_FLUSH_BATCH)
+ r5l_wake_reclaim(conf->log, 0);
+}
+
+static void r5c_update_log_state(struct r5l_log *log)
+{
+ struct r5conf *conf = log->rdev->mddev->private;
+ sector_t used_space = r5l_used_space(log);
+
+ if (used_space > 3 * log->max_free_space) {
+ set_bit(R5C_LOG_CRITICAL, &conf->cache_state);
+ set_bit(R5C_LOG_TIGHT, &conf->cache_state);
+ } else if (used_space > 2 * log->max_free_space) {
+ clear_bit(R5C_LOG_CRITICAL, &conf->cache_state);
+ set_bit(R5C_LOG_TIGHT, &conf->cache_state);
+ } else if (used_space < log->max_free_space) {
+ clear_bit(R5C_LOG_TIGHT, &conf->cache_state);
+ clear_bit(R5C_LOG_CRITICAL, &conf->cache_state);
+ } else /* max_free_space < used_space < 2 * max_free_space */
+ clear_bit(R5C_LOG_CRITICAL, &conf->cache_state);
+}
+
/*
* Freeze the stripe, thus send the stripe into reclaim path.
*
@@ -198,10 +260,9 @@ void r5c_freeze_stripe_for_reclaim(struct stripe_head *sh)
{
struct r5conf *conf = sh->raid_conf;
- if (!conf->log)
+ if (!conf->log || test_bit(STRIPE_R5C_FROZEN, &sh->state))
return;
- WARN_ON(test_bit(STRIPE_R5C_FROZEN, &sh->state));
set_bit(STRIPE_R5C_FROZEN, &sh->state);
if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
@@ -356,8 +417,11 @@ static struct bio *r5l_bio_alloc(struct r5l_log *log)
static void r5_reserve_log_entry(struct r5l_log *log, struct r5l_io_unit *io)
{
+ WARN_ON(!mutex_is_locked(&log->io_mutex));
+ WARN_ON(!r5l_has_free_space(log, BLOCK_SECTORS));
log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS);
+ r5c_update_log_state(log);
/*
* If we filled up the log device start from the beginning again,
* which will require a new bio.
@@ -475,6 +539,7 @@ static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
int meta_size;
int ret;
struct r5l_io_unit *io;
+ unsigned long flags;
meta_size =
((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
@@ -518,6 +583,14 @@ static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
atomic_inc(&io->pending_stripe);
sh->log_io = io;
+ if (sh->log_start == MaxSector) {
+ BUG_ON(!list_empty(&sh->r5c));
+ sh->log_start = io->log_start;
+ spin_lock_irqsave(&log->stripe_in_cache_lock, flags);
+ list_add_tail(&sh->r5c,
+ &log->stripe_in_cache);
+ spin_unlock_irqrestore(&log->stripe_in_cache_lock, flags);
+ }
return 0;
}
@@ -527,6 +600,7 @@ static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
*/
int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
{
+ struct r5conf *conf = sh->raid_conf;
int write_disks = 0;
int data_pages, parity_pages;
int meta_size;
@@ -590,19 +664,31 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
mutex_lock(&log->io_mutex);
/* meta + data */
reserve = (1 + write_disks) << (PAGE_SHIFT - 9);
- if (!r5l_has_free_space(log, reserve)) {
- spin_lock(&log->no_space_stripes_lock);
- list_add_tail(&sh->log_list, &log->no_space_stripes);
- spin_unlock(&log->no_space_stripes_lock);
- r5l_wake_reclaim(log, reserve);
- } else {
- ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
- if (ret) {
- spin_lock_irq(&log->io_list_lock);
- list_add_tail(&sh->log_list, &log->no_mem_stripes);
- spin_unlock_irq(&log->io_list_lock);
+ if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state)) {
+ sector_t last_checkpoint;
+
+ spin_lock(&log->stripe_in_cache_lock);
+ last_checkpoint = (list_first_entry(&log->stripe_in_cache,
+ struct stripe_head, r5c))->log_start;
+ spin_unlock(&log->stripe_in_cache_lock);
+ if (sh->log_start != last_checkpoint) {
+ spin_lock(&log->no_space_stripes_lock);
+ list_add_tail(&sh->log_list, &log->no_space_stripes);
+ spin_unlock(&log->no_space_stripes_lock);
+ mutex_unlock(&log->io_mutex);
+ return -ENOSPC;
+ } else if (!r5l_has_free_space(log, reserve)) {
+ WARN(1, "%s: run out of journal space\n", __func__);
+ BUG();
}
+ pr_debug("%s: write sh %lu to free log space\n", __func__, sh->sector);
+ }
+ ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
+ if (ret) {
+ spin_lock_irq(&log->io_list_lock);
+ list_add_tail(&sh->log_list, &log->no_mem_stripes);
+ spin_unlock_irq(&log->io_list_lock);
}
mutex_unlock(&log->io_mutex);
@@ -639,12 +725,17 @@ int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
/* This will run after log space is reclaimed */
static void r5l_run_no_space_stripes(struct r5l_log *log)
{
- struct stripe_head *sh;
+ struct r5conf *conf = log->rdev->mddev->private;
+ struct stripe_head *sh, *next;
+ sector_t last_checkpoint;
spin_lock(&log->no_space_stripes_lock);
- while (!list_empty(&log->no_space_stripes)) {
- sh = list_first_entry(&log->no_space_stripes,
- struct stripe_head, log_list);
+ last_checkpoint = (list_first_entry(&log->stripe_in_cache,
+ struct stripe_head, r5c))->log_start;
+ list_for_each_entry_safe(sh, next, &log->no_space_stripes, log_list) {
+ if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
+ sh->log_start != last_checkpoint)
+ continue;
list_del_init(&sh->log_list);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
@@ -652,10 +743,32 @@ static void r5l_run_no_space_stripes(struct r5l_log *log)
spin_unlock(&log->no_space_stripes_lock);
}
+static sector_t r5c_calculate_last_cp(struct r5conf *conf)
+{
+ struct stripe_head *sh;
+ struct r5l_log *log = conf->log;
+ sector_t end = MaxSector;
+ unsigned long flags;
+
+ spin_lock_irqsave(&log->stripe_in_cache_lock, flags);
+ if (list_empty(&conf->log->stripe_in_cache)) {
+ /* all stripes flushed */
+ spin_unlock_irqrestore(&log->stripe_in_cache_lock, flags);
+ return log->next_checkpoint;
+ }
+ sh = list_first_entry(&conf->log->stripe_in_cache,
+ struct stripe_head, r5c);
+ end = sh->log_start;
+ spin_unlock_irqrestore(&log->stripe_in_cache_lock, flags);
+ return end;
+}
+
static sector_t r5l_reclaimable_space(struct r5l_log *log)
{
+ struct r5conf *conf = log->rdev->mddev->private;
+
return r5l_ring_distance(log, log->last_checkpoint,
- log->next_checkpoint);
+ r5c_calculate_last_cp(conf));
}
static void r5l_run_no_mem_stripe(struct r5l_log *log)
@@ -830,14 +943,21 @@ static void r5l_write_super_and_discard_space(struct r5l_log *log,
blkdev_issue_discard(bdev, log->rdev->data_offset, end,
GFP_NOIO, 0);
}
+ mutex_lock(&log->io_mutex);
+ log->last_checkpoint = end;
+ r5c_update_log_state(log);
+ pr_debug("%s: set last_checkpoint = %lu\n", __func__, end);
+
+ log->last_cp_seq = log->next_cp_seq;
+ mutex_unlock(&log->io_mutex);
}
static void r5l_do_reclaim(struct r5l_log *log)
{
+ struct r5conf *conf = log->rdev->mddev->private;
sector_t reclaim_target = xchg(&log->reclaim_target, 0);
sector_t reclaimable;
sector_t next_checkpoint;
- u64 next_cp_seq;
spin_lock_irq(&log->io_list_lock);
/*
@@ -860,14 +980,12 @@ static void r5l_do_reclaim(struct r5l_log *log)
log->io_list_lock);
}
- next_checkpoint = log->next_checkpoint;
- next_cp_seq = log->next_cp_seq;
+ next_checkpoint = r5c_calculate_last_cp(conf);
spin_unlock_irq(&log->io_list_lock);
BUG_ON(reclaimable < 0);
if (reclaimable == 0)
return;
-
/*
* write_super will flush cache of each raid disk. We must write super
* here, because the log area might be reused soon and we don't want to
@@ -877,10 +995,7 @@ static void r5l_do_reclaim(struct r5l_log *log)
mutex_lock(&log->io_mutex);
log->last_checkpoint = next_checkpoint;
- log->last_cp_seq = next_cp_seq;
mutex_unlock(&log->io_mutex);
-
- r5l_run_no_space_stripes(log);
}
static void r5l_reclaim_thread(struct md_thread *thread)
@@ -891,7 +1006,9 @@ static void r5l_reclaim_thread(struct md_thread *thread)
if (!log)
return;
+ r5c_do_reclaim(conf);
r5l_do_reclaim(log);
+ md_wakeup_thread(mddev->thread);
}
void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
@@ -899,6 +1016,8 @@ void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
unsigned long target;
unsigned long new = (unsigned long)space; /* overflow in theory */
+ if (!log)
+ return;
do {
target = log->reclaim_target;
if (new < target)
@@ -926,7 +1045,7 @@ void r5l_quiesce(struct r5l_log *log, int state)
/* make sure r5l_write_super_and_discard_space exits */
mddev = log->rdev->mddev;
wake_up(&mddev->sb_wait);
- r5l_wake_reclaim(log, -1L);
+ r5l_wake_reclaim(log, MaxSector);
md_unregister_thread(&log->reclaim_thread);
r5l_do_reclaim(log);
}
@@ -1207,14 +1326,39 @@ static void r5l_write_super(struct r5l_log *log, sector_t cp)
set_bit(MD_CHANGE_DEVS, &mddev->flags);
}
-static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh)
+/*
+ * r5c_flush_cache will move stripe from cached list to handle_list or
+ * r5c_priority_list
+ *
+ * return 1 if the stripe is moved, and 0 if the stripe is not moved
+ * must hold conf->device_lock
+ */
+static int r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh,
+ bool priority)
{
- list_del_init(&sh->lru);
+ BUG_ON(list_empty(&sh->lru));
+
+ BUG_ON(test_bit(STRIPE_R5C_PRIORITY, &sh->state) &&
+ !test_bit(STRIPE_HANDLE, &sh->state));
+
+ if (test_bit(STRIPE_R5C_PRIORITY, &sh->state))
+ return 0;
+ if (test_bit(STRIPE_HANDLE, &sh->state) && !priority)
+ return 0;
+
r5c_freeze_stripe_for_reclaim(sh);
- atomic_inc(&conf->active_stripes);
+ if (!test_and_set_bit(STRIPE_HANDLE, &sh->state)) {
+ atomic_inc(&conf->active_stripes);
+ }
+ clear_bit(STRIPE_DELAYED, &sh->state);
+ clear_bit(STRIPE_BIT_DELAY, &sh->state);
+ if (priority)
+ set_bit(STRIPE_R5C_PRIORITY, &sh->state);
+
+ list_del_init(&sh->lru);
atomic_inc(&sh->count);
- set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
+ return 1;
}
/* if num <= 0, flush all stripes
@@ -1228,20 +1372,28 @@ int r5c_flush_cache(struct r5conf *conf, int num)
assert_spin_locked(&conf->device_lock);
if (!conf->log)
return 0;
+
list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru) {
- r5c_flush_stripe(conf, sh);
- count++;
+ count += r5c_flush_stripe(conf, sh, false);
if (num > 0 && count >= num && count >=
R5C_FULL_STRIPE_FLUSH_BATCH)
return count;
}
list_for_each_entry_safe(sh, next, &conf->r5c_partial_stripe_list, lru) {
- r5c_flush_stripe(conf, sh);
- count++;
+ count += r5c_flush_stripe(conf, sh, false);
if (num > 0 && count == num)
return count;
}
+
+ if (num <= 0) {
+ list_for_each_entry_safe(sh, next, &conf->delayed_list, lru) {
+ if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) ||
+ test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state))
+ r5c_flush_stripe(conf, sh, false);
+ }
+ r5l_run_no_space_stripes(conf->log);
+ }
return count;
}
@@ -1349,6 +1501,7 @@ void r5c_handle_stripe_written(struct r5conf *conf,
struct stripe_head *sh) {
int i;
int do_wakeup = 0;
+ unsigned long flags;
if (test_and_clear_bit(STRIPE_R5C_WRITTEN, &sh->state)) {
WARN_ON(!test_bit(STRIPE_R5C_FROZEN, &sh->state));
@@ -1361,6 +1514,11 @@ void r5c_handle_stripe_written(struct r5conf *conf,
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
do_wakeup = 1;
}
+ spin_lock_irqsave(&conf->log->stripe_in_cache_lock, flags);
+ list_del_init(&sh->r5c);
+ spin_unlock_irqrestore(&conf->log->stripe_in_cache_lock, flags);
+ sh->log_start = MaxSector;
+ clear_bit(STRIPE_R5C_PRIORITY, &sh->state);
}
if (do_wakeup)
@@ -1371,6 +1529,7 @@ int
r5c_cache_data(struct r5l_log *log, struct stripe_head *sh,
struct stripe_head_state *s)
{
+ struct r5conf *conf = sh->raid_conf;
int pages;
int meta_size;
int reserve;
@@ -1413,19 +1572,33 @@ r5c_cache_data(struct r5l_log *log, struct stripe_head *sh,
mutex_lock(&log->io_mutex);
/* meta + data */
reserve = (1 + pages) << (PAGE_SHIFT - 9);
- if (!r5l_has_free_space(log, reserve)) {
- spin_lock(&log->no_space_stripes_lock);
- list_add_tail(&sh->log_list, &log->no_space_stripes);
- spin_unlock(&log->no_space_stripes_lock);
- r5l_wake_reclaim(log, reserve);
- } else {
- ret = r5l_log_stripe(log, sh, pages, 0);
- if (ret) {
- spin_lock_irq(&log->io_list_lock);
- list_add_tail(&sh->log_list, &log->no_mem_stripes);
- spin_unlock_irq(&log->io_list_lock);
+ if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state)) {
+ sector_t last_checkpoint;
+
+ spin_lock(&log->stripe_in_cache_lock);
+ last_checkpoint = (list_first_entry(&log->stripe_in_cache,
+ struct stripe_head, r5c))->log_start;
+ spin_unlock(&log->stripe_in_cache_lock);
+ if (sh->log_start != last_checkpoint) {
+ spin_lock(&log->no_space_stripes_lock);
+ list_add_tail(&sh->log_list, &log->no_space_stripes);
+ spin_unlock(&log->no_space_stripes_lock);
+
+ mutex_unlock(&log->io_mutex);
+ return -ENOSPC;
}
+ pr_debug("%s: write sh %lu to free log space\n", __func__, sh->sector);
+ }
+ if (!r5l_has_free_space(log, reserve)) {
+ pr_err("%s: cannot reserve space %d\n", __func__, reserve);
+ BUG();
+ }
+ ret = r5l_log_stripe(log, sh, pages, 0);
+ if (ret) {
+ spin_lock_irq(&log->io_list_lock);
+ list_add_tail(&sh->log_list, &log->no_mem_stripes);
+ spin_unlock_irq(&log->io_list_lock);
}
mutex_unlock(&log->io_mutex);
@@ -1435,12 +1608,45 @@ r5c_cache_data(struct r5l_log *log, struct stripe_head *sh,
void r5c_do_reclaim(struct r5conf *conf)
{
struct r5l_log *log = conf->log;
-
- assert_spin_locked(&conf->device_lock);
+ struct stripe_head *sh, *next;
+ int count = 0;
+ unsigned long flags;
+ sector_t last_checkpoint;
if (!log)
return;
- r5c_flush_cache(conf, 0);
+
+ if (!test_bit(R5C_LOG_CRITICAL, &conf->cache_state)) {
+ /* flush all full stripes */
+ spin_lock_irqsave(&conf->device_lock, flags);
+ list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru)
+ r5c_flush_stripe(conf, sh, false);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+
+ if (test_bit(R5C_LOG_TIGHT, &conf->cache_state)) {
+ spin_lock_irqsave(&log->stripe_in_cache_lock, flags);
+ spin_lock(&conf->device_lock);
+ last_checkpoint = (list_first_entry(&log->stripe_in_cache,
+ struct stripe_head, r5c))->log_start;
+ list_for_each_entry(sh, &log->stripe_in_cache, r5c) {
+ if (sh->log_start == last_checkpoint) {
+ if (!list_empty(&sh->lru))
+ r5c_flush_stripe(conf, sh, true);
+ } else
+ break;
+ }
+ spin_unlock(&conf->device_lock);
+ spin_unlock_irqrestore(&log->stripe_in_cache_lock, flags);
+ pr_debug("%s: flushed %d stripes for log space\n", __func__, count);
+ } else if (test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state)) {
+ spin_lock_irqsave(&conf->device_lock, flags);
+ r5c_flush_cache(conf, R5C_RECLAIM_STRIPE_GROUP);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+ wake_up(&conf->wait_for_stripe);
+ md_wakeup_thread(conf->mddev->thread);
+ r5l_run_no_space_stripes(log);
}
static int r5l_load_log(struct r5l_log *log)
@@ -1500,6 +1706,9 @@ create:
if (log->max_free_space > RECLAIM_MAX_FREE_SPACE)
log->max_free_space = RECLAIM_MAX_FREE_SPACE;
log->last_checkpoint = cp;
+ mutex_lock(&log->io_mutex);
+ r5c_update_log_state(log);
+ mutex_unlock(&log->io_mutex);
__free_page(page);
@@ -1555,6 +1764,8 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
log->rdev->mddev, "reclaim");
if (!log->reclaim_thread)
goto reclaim_thread;
+ log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL;
+
init_waitqueue_head(&log->iounit_wait);
INIT_LIST_HEAD(&log->no_mem_stripes);
@@ -1564,6 +1775,8 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
/* flush full stripe */
log->r5c_state = R5C_STATE_WRITE_BACK;
+ INIT_LIST_HEAD(&log->stripe_in_cache);
+ spin_lock_init(&log->stripe_in_cache_lock);
if (r5l_load_log(log))
goto error;
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index cc4ac1d..a3d26ec 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -301,7 +301,9 @@ static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh,
else {
clear_bit(STRIPE_DELAYED, &sh->state);
clear_bit(STRIPE_BIT_DELAY, &sh->state);
- if (conf->worker_cnt_per_group == 0) {
+ if (test_bit(STRIPE_R5C_PRIORITY, &sh->state))
+ list_add_tail(&sh->lru, &conf->r5c_priority_list);
+ else if (conf->worker_cnt_per_group == 0) {
list_add_tail(&sh->lru, &conf->handle_list);
} else {
raid5_wakeup_stripe_thread(sh);
@@ -327,6 +329,7 @@ static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh,
if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state))
atomic_dec(&conf->r5c_cached_partial_stripes);
list_add_tail(&sh->lru, &conf->r5c_full_stripe_list);
+ r5c_check_cached_full_stripe(conf);
} else {
/* not full stripe */
if (!test_and_set_bit(STRIPE_R5C_PARTIAL_STRIPE,
@@ -697,9 +700,14 @@ raid5_get_active_stripe(struct r5conf *conf, sector_t sector,
}
if (noblock && sh == NULL)
break;
+
+ r5c_check_stripe_cache_usage(conf);
if (!sh) {
+ unsigned long before_jiffies;
set_bit(R5_INACTIVE_BLOCKED,
&conf->cache_state);
+ r5l_wake_reclaim(conf->log, 0);
+ before_jiffies = jiffies;
wait_event_lock_irq(
conf->wait_for_stripe,
!list_empty(conf->inactive_list + hash) &&
@@ -708,6 +716,9 @@ raid5_get_active_stripe(struct r5conf *conf, sector_t sector,
|| !test_bit(R5_INACTIVE_BLOCKED,
&conf->cache_state)),
*(conf->hash_locks + hash));
+ before_jiffies = jiffies - before_jiffies;
+ if (before_jiffies > 20)
+ pr_debug("%s: wait for sh takes %lu jiffies\n", __func__, before_jiffies);
clear_bit(R5_INACTIVE_BLOCKED,
&conf->cache_state);
} else {
@@ -915,18 +926,20 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
struct r5conf *conf = sh->raid_conf;
int i, disks = sh->disks;
struct stripe_head *head_sh = sh;
+ int ret;
might_sleep();
if (s->to_cache) {
- if (r5c_cache_data(conf->log, sh, s) == 0)
+ ret = r5c_cache_data(conf->log, sh, s);
+ if (ret == 0 || ret == -ENOSPC)
return;
- /* array is too big that meta data size > PAGE_SIZE */
- r5c_freeze_stripe_for_reclaim(sh);
}
- if (r5l_write_stripe(conf->log, sh) == 0)
+ ret = r5l_write_stripe(conf->log, sh);
+ if (ret == 0 || ret == -ENOSPC)
return;
+
for (i = disks; i--; ) {
int op, op_flags = 0;
int replace_only = 0;
@@ -2045,8 +2058,10 @@ static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp,
spin_lock_init(&sh->batch_lock);
INIT_LIST_HEAD(&sh->batch_list);
INIT_LIST_HEAD(&sh->lru);
+ INIT_LIST_HEAD(&sh->r5c);
atomic_set(&sh->count, 1);
atomic_set(&sh->dev_in_cache, 0);
+ sh->log_start = MaxSector;
for (i = 0; i < disks; i++) {
struct r5dev *dev = &sh->dev[i];
@@ -5057,7 +5072,9 @@ static struct stripe_head *__get_priority_stripe(struct r5conf *conf, int group)
struct list_head *handle_list = NULL;
struct r5worker_group *wg = NULL;
- if (conf->worker_cnt_per_group == 0) {
+ if (!list_empty(&conf->r5c_priority_list))
+ handle_list = &conf->r5c_priority_list;
+ else if (conf->worker_cnt_per_group == 0) {
handle_list = &conf->handle_list;
} else if (group != ANY_GROUP) {
handle_list = &conf->worker_groups[group].handle_list;
@@ -6049,7 +6066,6 @@ static void raid5d(struct md_thread *thread)
md_check_recovery(mddev);
spin_lock_irq(&conf->device_lock);
}
- r5c_do_reclaim(conf);
}
pr_debug("%d stripes handled\n", handled);
@@ -6675,6 +6691,7 @@ static struct r5conf *setup_conf(struct mddev *mddev)
init_waitqueue_head(&conf->wait_for_overlap);
INIT_LIST_HEAD(&conf->handle_list);
INIT_LIST_HEAD(&conf->hold_list);
+ INIT_LIST_HEAD(&conf->r5c_priority_list);
INIT_LIST_HEAD(&conf->delayed_list);
INIT_LIST_HEAD(&conf->bitmap_list);
bio_list_init(&conf->return_bi);
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 2ae027c..2d8222c 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -227,6 +227,8 @@ struct stripe_head {
struct r5l_io_unit *log_io;
struct list_head log_list;
atomic_t dev_in_cache;
+ sector_t log_start; /* first meta block on the journal */
+ struct list_head r5c; /* for r5c_cache->stripe_in_cache */
/**
* struct stripe_operations
* @target - STRIPE_OP_COMPUTE_BLK target
@@ -356,6 +358,7 @@ enum {
* in conf->r5c_full_stripe_list) */
STRIPE_R5C_FROZEN, /* r5c_cache frozen and being written out */
STRIPE_R5C_WRITTEN, /* ready for r5c_handle_stripe_written() */
+ STRIPE_R5C_PRIORITY, /* high priority stripe for log reclaim */
};
#define STRIPE_EXPAND_SYNC_FLAGS \
@@ -442,6 +445,26 @@ struct r5worker_group {
int stripes_cnt;
};
+enum r5_cache_state {
+ R5_INACTIVE_BLOCKED, /* release of inactive stripes blocked,
+ * waiting for 25% to be free
+ */
+ R5_ALLOC_MORE, /* It might help to allocate another
+ * stripe.
+ */
+ R5_DID_ALLOC, /* A stripe was allocated, don't allocate
+ * more until at least one has been
+ * released. This avoids flooding
+ * the cache.
+ */
+ R5C_LOG_TIGHT, /* journal device space tight, need to
+ * prioritize stripes at last_checkpoint
+ */
+ R5C_LOG_CRITICAL, /* journal device is running out of space,
+ * only process stripes at last_checkpoint
+ */
+};
+
struct r5conf {
struct hlist_head *stripe_hashtbl;
/* only protect corresponding hash list and inactive_list */
@@ -480,6 +503,7 @@ struct r5conf {
struct list_head handle_list; /* stripes needing handling */
struct list_head hold_list; /* preread ready stripes */
+ struct list_head r5c_priority_list; /* high priority stripes for reclaim */
struct list_head delayed_list; /* stripes that have plugged requests */
struct list_head bitmap_list; /* stripes delaying awaiting bitmap update */
struct bio *retry_read_aligned; /* currently retrying aligned bios */
@@ -543,17 +567,6 @@ struct r5conf {
wait_queue_head_t wait_for_stripe;
wait_queue_head_t wait_for_overlap;
unsigned long cache_state;
-#define R5_INACTIVE_BLOCKED 1 /* release of inactive stripes blocked,
- * waiting for 25% to be free
- */
-#define R5_ALLOC_MORE 2 /* It might help to allocate another
- * stripe.
- */
-#define R5_DID_ALLOC 4 /* A stripe was allocated, don't allocate
- * more until at least one has been
- * released. This avoids flooding
- * the cache.
- */
struct shrinker shrinker;
int pool_size; /* number of disks in stripeheads in pool */
spinlock_t device_lock;
@@ -665,5 +678,7 @@ extern void r5c_freeze_stripe_for_reclaim(struct stripe_head *sh);
extern void r5c_do_reclaim(struct r5conf *conf);
extern int r5c_flush_cache(struct r5conf *conf, int num);
extern struct md_sysfs_entry r5c_state;
+extern void r5c_check_stripe_cache_usage(struct r5conf *conf);
+extern void r5c_check_cached_full_stripe(struct r5conf *conf);
#endif
--
2.9.3
^ permalink raw reply related
* [PATCH v2 2/6] r5cache: sysfs entry r5c_state
From: Song Liu @ 2016-09-26 23:30 UTC (permalink / raw)
To: linux-raid
Cc: neilb, shli, kernel-team, dan.j.williams, hch, liuzhengyuang521,
liuzhengyuan, Song Liu
In-Reply-To: <20160926233050.3351081-1-songliubraving@fb.com>
r5c_state have 4 states:
* no-cache;
* write-through (write journal only);
* write-back (w/ write cache);
* cache-broken (journal missing or Faulty)
When there is functional write cache, r5c_state is a knob to
switch between write-back and write-through.
When the journal device is broken, the raid array is forced
in readonly mode. In this case, r5c_state can be used to
remove "journal feature", and thus make the array read-write
without journal. By writing into r5c_cache_mode, the array
can transit from cache-broken to no-cache, which removes
journal feature for the array.
Signed-off-by: Song Liu <songliubraving@fb.com>
---
drivers/md/raid5-cache.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/md/raid5.c | 1 +
drivers/md/raid5.h | 2 ++
3 files changed, 60 insertions(+)
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 6b28461..0a0b16a 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -54,6 +54,9 @@ enum r5c_state {
R5C_STATE_CACHE_BROKEN = 3,
};
+static char *r5c_state_str[] = {"no-cache", "write-through",
+ "write-back", "cache-broken"};
+
struct r5l_log {
struct md_rdev *rdev;
@@ -1242,6 +1245,60 @@ int r5c_flush_cache(struct r5conf *conf, int num)
return count;
}
+ssize_t r5c_state_show(struct mddev *mddev, char *page)
+{
+ struct r5conf *conf = mddev->private;
+ int val = 0;
+ int ret = 0;
+
+ if (conf->log)
+ val = conf->log->r5c_state;
+ else if (test_bit(MD_HAS_JOURNAL, &mddev->flags))
+ val = R5C_STATE_CACHE_BROKEN;
+ ret += snprintf(page, PAGE_SIZE - ret, "%d: %s\n",
+ val, r5c_state_str[val]);
+ return ret;
+}
+
+ssize_t r5c_state_store(struct mddev *mddev, const char *page, size_t len)
+{
+ struct r5conf *conf = mddev->private;
+ struct r5l_log *log = conf->log;
+ int val;
+
+ if (kstrtoint(page, 10, &val))
+ return -EINVAL;
+ if (!log && val != R5C_STATE_NO_CACHE)
+ return -EINVAL;
+
+ if (val < R5C_STATE_NO_CACHE || val > R5C_STATE_WRITE_BACK)
+ return -EINVAL;
+ if (val == R5C_STATE_NO_CACHE) {
+ if (conf->log &&
+ !test_bit(Faulty, &log->rdev->flags)) {
+ pr_err("md/raid:%s: journal device is in use, cannot remove it\n",
+ mdname(mddev));
+ return -EINVAL;
+ }
+ }
+
+ spin_lock_irq(&conf->device_lock);
+ if (log)
+ conf->log->r5c_state = val;
+ if (val == R5C_STATE_NO_CACHE) {
+ clear_bit(MD_HAS_JOURNAL, &mddev->flags);
+ set_bit(MD_UPDATE_SB_FLAGS, &mddev->flags);
+ }
+ spin_unlock_irq(&conf->device_lock);
+ pr_info("md/raid:%s: setting r5c cache mode to %d: %s\n",
+ mdname(mddev), val, r5c_state_str[val]);
+ return len;
+}
+
+struct md_sysfs_entry
+r5c_state = __ATTR(r5c_state, S_IRUGO | S_IWUSR,
+ r5c_state_show, r5c_state_store);
+
int r5c_handle_stripe_dirtying(struct r5conf *conf,
struct stripe_head *sh,
struct stripe_head_state *s,
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 25b411d..cc4ac1d 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6375,6 +6375,7 @@ static struct attribute *raid5_attrs[] = {
&raid5_group_thread_cnt.attr,
&raid5_skip_copy.attr,
&raid5_rmw_level.attr,
+ &r5c_state.attr,
NULL,
};
static struct attribute_group raid5_attrs_group = {
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 71e67ba..2ae027c 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -664,4 +664,6 @@ r5c_handle_stripe_written(struct r5conf *conf, struct stripe_head *sh);
extern void r5c_freeze_stripe_for_reclaim(struct stripe_head *sh);
extern void r5c_do_reclaim(struct r5conf *conf);
extern int r5c_flush_cache(struct r5conf *conf, int num);
+extern struct md_sysfs_entry r5c_state;
+
#endif
--
2.9.3
^ permalink raw reply related
* [PATCH v2 1/6] r5cache: write part of r5cache
From: Song Liu @ 2016-09-26 23:30 UTC (permalink / raw)
To: linux-raid
Cc: neilb, shli, kernel-team, dan.j.williams, hch, liuzhengyuang521,
liuzhengyuan, Song Liu
In-Reply-To: <20160926233050.3351081-1-songliubraving@fb.com>
This is the write part of r5cache. The cache is integrated with
stripe cache of raid456. It leverages code of r5l_log to write
data to journal device.
r5cache split current write path into 2 parts: the write path
and the reclaim path. The write path is as following:
1. write data to journal
(r5c_handle_stripe_dirtying, r5c_cache_data)
2. call bio_endio
(r5c_handle_data_cached, r5c_return_dev_pending_writes).
Then the reclaim path is as:
1. Freeze the stripe (r5c_freeze_stripe_for_reclaim)
2. Calcualte parity (reconstruct or RMW)
3. Write parity (and maybe some other data) to journal device
4. Write data and parity to RAID disks
Step 3 and 4 of reclaim path is very similar to write path of
raid5 journal.
With r5cache, write operation does not wait for parity calculation
and write out, so the write latency is lower (1 write to journal
device vs. read and then write to raid disks). Also, r5cache will
reduce RAID overhead (multipile IO due to read-modify-write of
parity) and provide more opportunities of full stripe writes.
r5cache adds 4 flags to stripe_head.state:
- STRIPE_R5C_PARTIAL_STRIPE,
- STRIPE_R5C_FULL_STRIPE,
- STRIPE_R5C_FROZEN and
- STRIPE_R5C_WRITTEN.
The write path runs w/ STRIPE_R5C_FROZEN == 0. Cache writes start
from r5c_handle_stripe_dirtying(), where bit R5_Wantcache is set
for devices with bio in towrite. Then, the data is written to
the journal through r5l_log implementation. Once the data is in
the journal, we set bit R5_InCache, and presue bio_endio for
these writes.
The reclaim path starts by setting STRIPE_R5C_FROZEN. This makes
the stripe into reclaim. If some write operation arrives at this
time, it will be handled as raid5 journal (calculate parity,
write to jorunal, write to disks, bio_endio).
Once frozen, the stripe is sent back to raid5 state machine,
where handle_stripe_dirtying will evaluate the stripe for
reconstruct writes or RMW writes (read data and calculate parity).
For RMW, the code allocates an extra page for each data block
being updated. This is stored in r5dev->page and the old data
is read into it. Then the prexor calculation subtracts ->page
from the parity block, and the reconstruct calculation adds the
->orig_page data back into the parity block.
r5cache naturally excludes SkipCopy. With R5_Wantcache bit set,
async_copy_data will not skip copy.
Before writing data to RAID disks, the r5l_log logic stores
parity (and non-overwrite data) to the journal.
Instead of inactive_list, stripes with cached data are tracked in
r5conf->r5c_full_stripe_list and r5conf->r5c_partial_stripe_list.
There are some known limitations of the cache implementation:
1. Write cache only covers full page writes (R5_OVERWRITE). Writes
of smaller granularity are write through.
2. Only one log io (sh->log_io) for each stripe at anytime. Later
writes for the same stripe have to wait. This can be improved by
moving log_io to r5dev.
Signed-off-by: Song Liu <songliubraving@fb.com>
---
drivers/md/raid5-cache.c | 292 +++++++++++++++++++++++++++++++++++++++++++++--
drivers/md/raid5.c | 187 ++++++++++++++++++++++++++----
drivers/md/raid5.h | 31 ++++-
3 files changed, 479 insertions(+), 31 deletions(-)
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 1b1ab4a..6b28461 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -34,12 +34,26 @@
#define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */
#define RECLAIM_MAX_FREE_SPACE_SHIFT (2)
+/* wake up reclaim thread periodically */
+#define R5C_RECLAIM_WAKEUP_INTERVAL (5 * HZ)
+/* start flush with these full stripes */
+#define R5C_FULL_STRIPE_FLUSH_BATCH 8
+/* reclaim stripes in groups */
+#define R5C_RECLAIM_STRIPE_GROUP (NR_STRIPE_HASH_LOCKS * 2)
+
/*
* We only need 2 bios per I/O unit to make progress, but ensure we
* have a few more available to not get too tight.
*/
#define R5L_POOL_SIZE 4
+enum r5c_state {
+ R5C_STATE_NO_CACHE = 0,
+ R5C_STATE_WRITE_THROUGH = 1,
+ R5C_STATE_WRITE_BACK = 2,
+ R5C_STATE_CACHE_BROKEN = 3,
+};
+
struct r5l_log {
struct md_rdev *rdev;
@@ -96,6 +110,9 @@ struct r5l_log {
spinlock_t no_space_stripes_lock;
bool need_cache_flush;
+
+ /* for r5c_cache */
+ enum r5c_state r5c_state;
};
/*
@@ -168,12 +185,79 @@ static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
io->state = state;
}
+/*
+ * Freeze the stripe, thus send the stripe into reclaim path.
+ *
+ * This function should only be called from raid5d that handling this stripe,
+ * or when holds conf->device_lock
+ */
+void r5c_freeze_stripe_for_reclaim(struct stripe_head *sh)
+{
+ struct r5conf *conf = sh->raid_conf;
+
+ if (!conf->log)
+ return;
+
+ WARN_ON(test_bit(STRIPE_R5C_FROZEN, &sh->state));
+ set_bit(STRIPE_R5C_FROZEN, &sh->state);
+
+ if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
+ atomic_inc(&conf->preread_active_stripes);
+
+ if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) {
+ BUG_ON(atomic_read(&conf->r5c_cached_partial_stripes) == 0);
+ atomic_dec(&conf->r5c_cached_partial_stripes);
+ }
+
+ if (test_and_clear_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
+ BUG_ON(atomic_read(&conf->r5c_cached_full_stripes) == 0);
+ atomic_dec(&conf->r5c_cached_full_stripes);
+ }
+}
+
+static void r5c_handle_data_cached(struct stripe_head *sh)
+{
+ int i;
+
+ for (i = sh->disks; i--; )
+ if (test_and_clear_bit(R5_Wantcache, &sh->dev[i].flags)) {
+ set_bit(R5_InCache, &sh->dev[i].flags);
+ clear_bit(R5_LOCKED, &sh->dev[i].flags);
+ atomic_inc(&sh->dev_in_cache);
+ }
+}
+
+/*
+ * this journal write must contain full parity,
+ * it may also contain some data pages
+ */
+static void r5c_handle_parity_cached(struct stripe_head *sh)
+{
+ int i;
+
+ for (i = sh->disks; i--; )
+ if (test_bit(R5_InCache, &sh->dev[i].flags))
+ set_bit(R5_Wantwrite, &sh->dev[i].flags);
+ set_bit(STRIPE_R5C_WRITTEN, &sh->state);
+}
+
+static void r5c_finish_cache_stripe(struct stripe_head *sh)
+{
+ if (test_bit(STRIPE_R5C_FROZEN, &sh->state))
+ r5c_handle_parity_cached(sh);
+ else
+ r5c_handle_data_cached(sh);
+}
+
static void r5l_io_run_stripes(struct r5l_io_unit *io)
{
struct stripe_head *sh, *next;
list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
list_del_init(&sh->log_list);
+
+ r5c_finish_cache_stripe(sh);
+
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
@@ -402,7 +486,8 @@ static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
io = log->current_io;
for (i = 0; i < sh->disks; i++) {
- if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
+ if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) &&
+ !test_bit(R5_Wantcache, &sh->dev[i].flags))
continue;
if (i == sh->pd_idx || i == sh->qd_idx)
continue;
@@ -412,18 +497,19 @@ static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
r5l_append_payload_page(log, sh->dev[i].page);
}
- if (sh->qd_idx >= 0) {
+ if (parity_pages == 2) {
r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
sh->sector, sh->dev[sh->pd_idx].log_checksum,
sh->dev[sh->qd_idx].log_checksum, true);
r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
r5l_append_payload_page(log, sh->dev[sh->qd_idx].page);
- } else {
+ } else if (parity_pages == 1) {
r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
sh->sector, sh->dev[sh->pd_idx].log_checksum,
0, false);
r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
- }
+ } else
+ BUG_ON(parity_pages != 0);
list_add_tail(&sh->log_list, &io->stripe_list);
atomic_inc(&io->pending_stripe);
@@ -432,7 +518,6 @@ static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
return 0;
}
-static void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
/*
* running in raid5d, where reclaim could wait for raid5d too (when it flushes
* data from log to raid disks), so we shouldn't wait for reclaim here
@@ -456,11 +541,17 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
return -EAGAIN;
}
+ WARN_ON(!test_bit(STRIPE_R5C_FROZEN, &sh->state));
+
for (i = 0; i < sh->disks; i++) {
void *addr;
if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
continue;
+
+ if (test_bit(R5_InCache, &sh->dev[i].flags))
+ continue;
+
write_disks++;
/* checksum is already calculated in last run */
if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
@@ -473,6 +564,9 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
parity_pages = 1 + !!(sh->qd_idx >= 0);
data_pages = write_disks - parity_pages;
+ pr_debug("%s: write %d data_pages and %d parity_pages\n",
+ __func__, data_pages, parity_pages);
+
meta_size =
((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
* data_pages) +
@@ -735,7 +829,6 @@ static void r5l_write_super_and_discard_space(struct r5l_log *log,
}
}
-
static void r5l_do_reclaim(struct r5l_log *log)
{
sector_t reclaim_target = xchg(&log->reclaim_target, 0);
@@ -798,7 +891,7 @@ static void r5l_reclaim_thread(struct md_thread *thread)
r5l_do_reclaim(log);
}
-static void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
+void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
{
unsigned long target;
unsigned long new = (unsigned long)space; /* overflow in theory */
@@ -1111,6 +1204,188 @@ static void r5l_write_super(struct r5l_log *log, sector_t cp)
set_bit(MD_CHANGE_DEVS, &mddev->flags);
}
+static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh)
+{
+ list_del_init(&sh->lru);
+ r5c_freeze_stripe_for_reclaim(sh);
+ atomic_inc(&conf->active_stripes);
+ atomic_inc(&sh->count);
+ set_bit(STRIPE_HANDLE, &sh->state);
+ raid5_release_stripe(sh);
+}
+
+/* if num <= 0, flush all stripes
+ * if num > 0, flush at most num stripes
+ */
+int r5c_flush_cache(struct r5conf *conf, int num)
+{
+ int count = 0;
+ struct stripe_head *sh, *next;
+
+ assert_spin_locked(&conf->device_lock);
+ if (!conf->log)
+ return 0;
+ list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru) {
+ r5c_flush_stripe(conf, sh);
+ count++;
+ if (num > 0 && count >= num && count >=
+ R5C_FULL_STRIPE_FLUSH_BATCH)
+ return count;
+ }
+
+ list_for_each_entry_safe(sh, next, &conf->r5c_partial_stripe_list, lru) {
+ r5c_flush_stripe(conf, sh);
+ count++;
+ if (num > 0 && count == num)
+ return count;
+ }
+ return count;
+}
+
+int r5c_handle_stripe_dirtying(struct r5conf *conf,
+ struct stripe_head *sh,
+ struct stripe_head_state *s,
+ int disks) {
+ struct r5l_log *log = conf->log;
+ int i;
+ struct r5dev *dev;
+
+ if (!log || test_bit(STRIPE_R5C_FROZEN, &sh->state))
+ return -EAGAIN;
+
+ if (conf->log->r5c_state == R5C_STATE_WRITE_THROUGH ||
+ conf->quiesce != 0 || conf->mddev->degraded != 0) {
+ /* write through mode */
+ r5c_freeze_stripe_for_reclaim(sh);
+ return -EAGAIN;
+ }
+
+ s->to_cache = 0;
+
+ for (i = disks; i--; ) {
+ dev = &sh->dev[i];
+ /* if none-overwrite, use the reclaim path (write through) */
+ if (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags) &&
+ !test_bit(R5_InCache, &dev->flags)) {
+ r5c_freeze_stripe_for_reclaim(sh);
+ return -EAGAIN;
+ }
+ }
+
+ for (i = disks; i--; ) {
+ dev = &sh->dev[i];
+ if (dev->towrite) {
+ set_bit(R5_Wantcache, &dev->flags);
+ set_bit(R5_Wantdrain, &dev->flags);
+ set_bit(R5_LOCKED, &dev->flags);
+ s->to_cache++;
+ }
+ }
+
+ if (s->to_cache)
+ set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
+
+ return 0;
+}
+
+void r5c_handle_stripe_written(struct r5conf *conf,
+ struct stripe_head *sh) {
+ int i;
+ int do_wakeup = 0;
+
+ if (test_and_clear_bit(STRIPE_R5C_WRITTEN, &sh->state)) {
+ WARN_ON(!test_bit(STRIPE_R5C_FROZEN, &sh->state));
+ clear_bit(STRIPE_R5C_FROZEN, &sh->state);
+
+ for (i = sh->disks; i--; ) {
+ if (test_and_clear_bit(R5_InCache, &sh->dev[i].flags))
+ atomic_dec(&sh->dev_in_cache);
+ clear_bit(R5_UPTODATE, &sh->dev[i].flags);
+ if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
+ do_wakeup = 1;
+ }
+ }
+
+ if (do_wakeup)
+ wake_up(&conf->wait_for_overlap);
+}
+
+int
+r5c_cache_data(struct r5l_log *log, struct stripe_head *sh,
+ struct stripe_head_state *s)
+{
+ int pages;
+ int meta_size;
+ int reserve;
+ int i;
+ int ret = 0;
+ int page_count = 0;
+
+ BUG_ON(!log);
+ BUG_ON(s->to_cache == 0);
+
+ for (i = 0; i < sh->disks; i++) {
+ void *addr;
+
+ if (!test_bit(R5_Wantcache, &sh->dev[i].flags))
+ continue;
+ addr = kmap_atomic(sh->dev[i].page);
+ sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
+ addr, PAGE_SIZE);
+ kunmap_atomic(addr);
+ page_count++;
+ }
+ WARN_ON(page_count != s->to_cache);
+
+ pages = s->to_cache;
+
+ meta_size =
+ ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
+ * pages);
+ /* Doesn't work with very big raid array */
+ if (meta_size + sizeof(struct r5l_meta_block) > PAGE_SIZE)
+ return -EINVAL;
+
+ /*
+ * The stripe must enter state machine again to call endio, so
+ * don't delay.
+ */
+ clear_bit(STRIPE_DELAYED, &sh->state);
+ atomic_inc(&sh->count);
+
+ mutex_lock(&log->io_mutex);
+ /* meta + data */
+ reserve = (1 + pages) << (PAGE_SHIFT - 9);
+ if (!r5l_has_free_space(log, reserve)) {
+ spin_lock(&log->no_space_stripes_lock);
+ list_add_tail(&sh->log_list, &log->no_space_stripes);
+ spin_unlock(&log->no_space_stripes_lock);
+
+ r5l_wake_reclaim(log, reserve);
+ } else {
+ ret = r5l_log_stripe(log, sh, pages, 0);
+ if (ret) {
+ spin_lock_irq(&log->io_list_lock);
+ list_add_tail(&sh->log_list, &log->no_mem_stripes);
+ spin_unlock_irq(&log->io_list_lock);
+ }
+ }
+
+ mutex_unlock(&log->io_mutex);
+ return 0;
+}
+
+void r5c_do_reclaim(struct r5conf *conf)
+{
+ struct r5l_log *log = conf->log;
+
+ assert_spin_locked(&conf->device_lock);
+
+ if (!log)
+ return;
+ r5c_flush_cache(conf, 0);
+}
+
static int r5l_load_log(struct r5l_log *log)
{
struct md_rdev *rdev = log->rdev;
@@ -1230,6 +1505,9 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
INIT_LIST_HEAD(&log->no_space_stripes);
spin_lock_init(&log->no_space_stripes_lock);
+ /* flush full stripe */
+ log->r5c_state = R5C_STATE_WRITE_BACK;
+
if (r5l_load_log(log))
goto error;
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index f94472d..25b411d 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -316,8 +316,25 @@ static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh,
< IO_THRESHOLD)
md_wakeup_thread(conf->mddev->thread);
atomic_dec(&conf->active_stripes);
- if (!test_bit(STRIPE_EXPANDING, &sh->state))
- list_add_tail(&sh->lru, temp_inactive_list);
+ if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
+ if (atomic_read(&sh->dev_in_cache) == 0) {
+ list_add_tail(&sh->lru, temp_inactive_list);
+ } else if (atomic_read(&sh->dev_in_cache) ==
+ conf->raid_disks - conf->max_degraded) {
+ /* full stripe */
+ if (!test_and_set_bit(STRIPE_R5C_FULL_STRIPE, &sh->state))
+ atomic_inc(&conf->r5c_cached_full_stripes);
+ if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state))
+ atomic_dec(&conf->r5c_cached_partial_stripes);
+ list_add_tail(&sh->lru, &conf->r5c_full_stripe_list);
+ } else {
+ /* not full stripe */
+ if (!test_and_set_bit(STRIPE_R5C_PARTIAL_STRIPE,
+ &sh->state))
+ atomic_inc(&conf->r5c_cached_partial_stripes);
+ list_add_tail(&sh->lru, &conf->r5c_partial_stripe_list);
+ }
+ }
}
}
@@ -901,6 +918,13 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
might_sleep();
+ if (s->to_cache) {
+ if (r5c_cache_data(conf->log, sh, s) == 0)
+ return;
+ /* array is too big that meta data size > PAGE_SIZE */
+ r5c_freeze_stripe_for_reclaim(sh);
+ }
+
if (r5l_write_stripe(conf->log, sh) == 0)
return;
for (i = disks; i--; ) {
@@ -1029,6 +1053,7 @@ again:
if (test_bit(R5_SkipCopy, &sh->dev[i].flags))
WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
+
sh->dev[i].vec.bv_page = sh->dev[i].page;
bi->bi_vcnt = 1;
bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
@@ -1115,7 +1140,7 @@ again:
static struct dma_async_tx_descriptor *
async_copy_data(int frombio, struct bio *bio, struct page **page,
sector_t sector, struct dma_async_tx_descriptor *tx,
- struct stripe_head *sh)
+ struct stripe_head *sh, int no_skipcopy)
{
struct bio_vec bvl;
struct bvec_iter iter;
@@ -1155,7 +1180,8 @@ async_copy_data(int frombio, struct bio *bio, struct page **page,
if (frombio) {
if (sh->raid_conf->skip_copy &&
b_offset == 0 && page_offset == 0 &&
- clen == STRIPE_SIZE)
+ clen == STRIPE_SIZE &&
+ !no_skipcopy)
*page = bio_page;
else
tx = async_memcpy(*page, bio_page, page_offset,
@@ -1237,7 +1263,7 @@ static void ops_run_biofill(struct stripe_head *sh)
while (rbi && rbi->bi_iter.bi_sector <
dev->sector + STRIPE_SECTORS) {
tx = async_copy_data(0, rbi, &dev->page,
- dev->sector, tx, sh);
+ dev->sector, tx, sh, 0);
rbi = r5_next_bio(rbi, dev->sector);
}
}
@@ -1364,7 +1390,8 @@ static int set_syndrome_sources(struct page **srcs,
if (i == sh->qd_idx || i == sh->pd_idx ||
(srctype == SYNDROME_SRC_ALL) ||
(srctype == SYNDROME_SRC_WANT_DRAIN &&
- test_bit(R5_Wantdrain, &dev->flags)) ||
+ (test_bit(R5_Wantdrain, &dev->flags) ||
+ test_bit(R5_InCache, &dev->flags))) ||
(srctype == SYNDROME_SRC_WRITTEN &&
dev->written))
srcs[slot] = sh->dev[i].page;
@@ -1543,9 +1570,18 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
static void ops_complete_prexor(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
+ int i;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
+
+ for (i = sh->disks; i--; )
+ if (sh->dev[i].page != sh->dev[i].orig_page) {
+ struct page *p = sh->dev[i].page;
+
+ sh->dev[i].page = sh->dev[i].orig_page;
+ put_page(p);
+ }
}
static struct dma_async_tx_descriptor *
@@ -1567,7 +1603,8 @@ ops_run_prexor5(struct stripe_head *sh, struct raid5_percpu *percpu,
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
/* Only process blocks that are known to be uptodate */
- if (test_bit(R5_Wantdrain, &dev->flags))
+ if (test_bit(R5_Wantdrain, &dev->flags) ||
+ test_bit(R5_InCache, &dev->flags))
xor_srcs[count++] = dev->page;
}
@@ -1618,6 +1655,10 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
again:
dev = &sh->dev[i];
+ if (test_and_clear_bit(R5_InCache, &dev->flags)) {
+ BUG_ON(atomic_read(&sh->dev_in_cache) == 0);
+ atomic_dec(&sh->dev_in_cache);
+ }
spin_lock_irq(&sh->stripe_lock);
chosen = dev->towrite;
dev->towrite = NULL;
@@ -1625,7 +1666,8 @@ again:
BUG_ON(dev->written);
wbi = dev->written = chosen;
spin_unlock_irq(&sh->stripe_lock);
- WARN_ON(dev->page != dev->orig_page);
+ if (!test_bit(R5_Wantcache, &dev->flags))
+ WARN_ON(dev->page != dev->orig_page);
while (wbi && wbi->bi_iter.bi_sector <
dev->sector + STRIPE_SECTORS) {
@@ -1637,8 +1679,10 @@ again:
set_bit(R5_Discard, &dev->flags);
else {
tx = async_copy_data(1, wbi, &dev->page,
- dev->sector, tx, sh);
- if (dev->page != dev->orig_page) {
+ dev->sector, tx, sh,
+ test_bit(R5_Wantcache, &dev->flags));
+ if (dev->page != dev->orig_page &&
+ !test_bit(R5_Wantcache, &dev->flags)) {
set_bit(R5_SkipCopy, &dev->flags);
clear_bit(R5_UPTODATE, &dev->flags);
clear_bit(R5_OVERWRITE, &dev->flags);
@@ -1746,7 +1790,8 @@ again:
xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
- if (head_sh->dev[i].written)
+ if (head_sh->dev[i].written ||
+ test_bit(R5_InCache, &head_sh->dev[i].flags))
xor_srcs[count++] = dev->page;
}
} else {
@@ -2001,6 +2046,7 @@ static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp,
INIT_LIST_HEAD(&sh->batch_list);
INIT_LIST_HEAD(&sh->lru);
atomic_set(&sh->count, 1);
+ atomic_set(&sh->dev_in_cache, 0);
for (i = 0; i < disks; i++) {
struct r5dev *dev = &sh->dev[i];
@@ -2887,6 +2933,9 @@ schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
if (!expand)
clear_bit(R5_UPTODATE, &dev->flags);
s->locked++;
+ } else if (test_bit(R5_InCache, &dev->flags)) {
+ set_bit(R5_LOCKED, &dev->flags);
+ s->locked++;
}
}
/* if we are not expanding this is a proper write request, and
@@ -2926,6 +2975,9 @@ schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
set_bit(R5_LOCKED, &dev->flags);
clear_bit(R5_UPTODATE, &dev->flags);
s->locked++;
+ } else if (test_bit(R5_InCache, &dev->flags)) {
+ set_bit(R5_LOCKED, &dev->flags);
+ s->locked++;
}
}
if (!s->locked)
@@ -3577,6 +3629,9 @@ static void handle_stripe_dirtying(struct r5conf *conf,
int rmw = 0, rcw = 0, i;
sector_t recovery_cp = conf->mddev->recovery_cp;
+ if (r5c_handle_stripe_dirtying(conf, sh, s, disks) == 0)
+ return;
+
/* Check whether resync is now happening or should start.
* If yes, then the array is dirty (after unclean shutdown or
* initial creation), so parity in some stripes might be inconsistent.
@@ -3597,9 +3652,12 @@ static void handle_stripe_dirtying(struct r5conf *conf,
} else for (i = disks; i--; ) {
/* would I have to read this buffer for read_modify_write */
struct r5dev *dev = &sh->dev[i];
- if ((dev->towrite || i == sh->pd_idx || i == sh->qd_idx) &&
+ if ((dev->towrite || i == sh->pd_idx || i == sh->qd_idx ||
+ test_bit(R5_InCache, &dev->flags)) &&
!test_bit(R5_LOCKED, &dev->flags) &&
- !(test_bit(R5_UPTODATE, &dev->flags) ||
+ !((test_bit(R5_UPTODATE, &dev->flags) &&
+ (!test_bit(R5_InCache, &dev->flags) ||
+ dev->page != dev->orig_page)) ||
test_bit(R5_Wantcompute, &dev->flags))) {
if (test_bit(R5_Insync, &dev->flags))
rmw++;
@@ -3611,13 +3669,15 @@ static void handle_stripe_dirtying(struct r5conf *conf,
i != sh->pd_idx && i != sh->qd_idx &&
!test_bit(R5_LOCKED, &dev->flags) &&
!(test_bit(R5_UPTODATE, &dev->flags) ||
- test_bit(R5_Wantcompute, &dev->flags))) {
+ test_bit(R5_InCache, &dev->flags) ||
+ test_bit(R5_Wantcompute, &dev->flags))) {
if (test_bit(R5_Insync, &dev->flags))
rcw++;
else
rcw += 2*disks;
}
}
+
pr_debug("for sector %llu, rmw=%d rcw=%d\n",
(unsigned long long)sh->sector, rmw, rcw);
set_bit(STRIPE_HANDLE, &sh->state);
@@ -3629,10 +3689,18 @@ static void handle_stripe_dirtying(struct r5conf *conf,
(unsigned long long)sh->sector, rmw);
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
- if ((dev->towrite || i == sh->pd_idx || i == sh->qd_idx) &&
+ if (test_bit(R5_InCache, &dev->flags) &&
+ dev->page == dev->orig_page)
+ dev->page = alloc_page(GFP_NOIO); /* prexor */
+
+ if ((dev->towrite ||
+ i == sh->pd_idx || i == sh->qd_idx ||
+ test_bit(R5_InCache, &dev->flags)) &&
!test_bit(R5_LOCKED, &dev->flags) &&
- !(test_bit(R5_UPTODATE, &dev->flags) ||
- test_bit(R5_Wantcompute, &dev->flags)) &&
+ !((test_bit(R5_UPTODATE, &dev->flags) &&
+ (!test_bit(R5_InCache, &dev->flags) ||
+ dev->page != dev->orig_page)) ||
+ test_bit(R5_Wantcompute, &dev->flags)) &&
test_bit(R5_Insync, &dev->flags)) {
if (test_bit(STRIPE_PREREAD_ACTIVE,
&sh->state)) {
@@ -3658,6 +3726,7 @@ static void handle_stripe_dirtying(struct r5conf *conf,
i != sh->pd_idx && i != sh->qd_idx &&
!test_bit(R5_LOCKED, &dev->flags) &&
!(test_bit(R5_UPTODATE, &dev->flags) ||
+ test_bit(R5_InCache, &dev->flags) ||
test_bit(R5_Wantcompute, &dev->flags))) {
rcw++;
if (test_bit(R5_Insync, &dev->flags) &&
@@ -3697,7 +3766,7 @@ static void handle_stripe_dirtying(struct r5conf *conf,
*/
if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
(s->locked == 0 && (rcw == 0 || rmw == 0) &&
- !test_bit(STRIPE_BIT_DELAY, &sh->state)))
+ !test_bit(STRIPE_BIT_DELAY, &sh->state)))
schedule_reconstruction(sh, s, rcw == 0, 0);
}
@@ -4010,6 +4079,45 @@ static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh)
async_tx_quiesce(&tx);
}
+static void
+r5c_return_dev_pending_writes(struct r5conf *conf, struct r5dev *dev,
+ struct bio_list *return_bi)
+{
+ struct bio *wbi, *wbi2;
+
+ wbi = dev->written;
+ dev->written = NULL;
+ while (wbi && wbi->bi_iter.bi_sector <
+ dev->sector + STRIPE_SECTORS) {
+ wbi2 = r5_next_bio(wbi, dev->sector);
+ if (!raid5_dec_bi_active_stripes(wbi)) {
+ md_write_end(conf->mddev);
+ bio_list_add(return_bi, wbi);
+ }
+ wbi = wbi2;
+ }
+}
+
+static void r5c_handle_cached_data_endio(struct r5conf *conf,
+ struct stripe_head *sh, int disks, struct bio_list *return_bi)
+{
+ int i;
+
+ for (i = sh->disks; i--; ) {
+ if (test_bit(R5_InCache, &sh->dev[i].flags) &&
+ sh->dev[i].written) {
+ set_bit(R5_UPTODATE, &sh->dev[i].flags);
+ r5c_return_dev_pending_writes(conf, &sh->dev[i],
+ return_bi);
+ bitmap_endwrite(conf->mddev->bitmap, sh->sector,
+ STRIPE_SECTORS,
+ !test_bit(STRIPE_DEGRADED, &sh->state),
+ 0);
+ }
+ }
+ r5l_stripe_write_finished(sh);
+}
+
/*
* handle_stripe - do things to a stripe.
*
@@ -4188,6 +4296,10 @@ static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
if (rdev && !test_bit(Faulty, &rdev->flags))
do_recovery = 1;
}
+ if (test_bit(R5_InCache, &dev->flags) && dev->written)
+ s->just_cached++;
+ if (test_bit(R5_Wantcache, &dev->flags) && dev->written)
+ s->want_cache++;
}
if (test_bit(STRIPE_SYNCING, &sh->state)) {
/* If there is a failed device being replaced,
@@ -4353,6 +4465,16 @@ static void handle_stripe(struct stripe_head *sh)
analyse_stripe(sh, &s);
+ if (s.want_cache) {
+ /* we have finished r5c_handle_stripe_dirtying and
+ * ops_run_biodrain, but r5c_cache_data didn't finish because
+ * the journal device didn't have enough space. This time we
+ * should skip handle_stripe_dirtying and ops_run_biodrain
+ */
+ s.to_cache = s.want_cache;
+ goto finish;
+ }
+
if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
goto finish;
@@ -4416,7 +4538,7 @@ static void handle_stripe(struct stripe_head *sh)
struct r5dev *dev = &sh->dev[i];
if (test_bit(R5_LOCKED, &dev->flags) &&
(i == sh->pd_idx || i == sh->qd_idx ||
- dev->written)) {
+ dev->written || test_bit(R5_InCache, &dev->flags))) {
pr_debug("Writing block %d\n", i);
set_bit(R5_Wantwrite, &dev->flags);
if (prexor)
@@ -4456,6 +4578,12 @@ static void handle_stripe(struct stripe_head *sh)
test_bit(R5_Discard, &qdev->flags))))))
handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
+ if (s.just_cached)
+ r5c_handle_cached_data_endio(conf, sh, disks, &s.return_bi);
+
+ if (test_bit(STRIPE_R5C_FROZEN, &sh->state))
+ r5l_stripe_write_finished(sh);
+
/* Now we might consider reading some blocks, either to check/generate
* parity, or to satisfy requests
* or to load a block that is being partially written.
@@ -4467,13 +4595,17 @@ static void handle_stripe(struct stripe_head *sh)
|| s.expanding)
handle_stripe_fill(sh, &s, disks);
- /* Now to consider new write requests and what else, if anything
- * should be read. We do not handle new writes when:
+ r5c_handle_stripe_written(conf, sh);
+
+ /* Now to consider new write requests, cache write back and what else,
+ * if anything should be read. We do not handle new writes when:
* 1/ A 'write' operation (copy+xor) is already in flight.
* 2/ A 'check' operation is in flight, as it may clobber the parity
* block.
+ * 3/ A r5c cache log write is in flight.
*/
- if (s.to_write && !sh->reconstruct_state && !sh->check_state)
+ if ((s.to_write || test_bit(STRIPE_R5C_FROZEN, &sh->state)) &&
+ !sh->reconstruct_state && !sh->check_state && !sh->log_io)
handle_stripe_dirtying(conf, sh, &s, disks);
/* maybe we need to check and possibly fix the parity for this stripe
@@ -5192,7 +5324,7 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
* later we might have to read it again in order to reconstruct
* data on failed drives.
*/
- if (rw == READ && mddev->degraded == 0 &&
+ if (rw == READ && mddev->degraded == 0 && conf->log == NULL &&
mddev->reshape_position == MaxSector) {
bi = chunk_aligned_read(mddev, bi);
if (!bi)
@@ -5917,6 +6049,7 @@ static void raid5d(struct md_thread *thread)
md_check_recovery(mddev);
spin_lock_irq(&conf->device_lock);
}
+ r5c_do_reclaim(conf);
}
pr_debug("%d stripes handled\n", handled);
@@ -6583,6 +6716,11 @@ static struct r5conf *setup_conf(struct mddev *mddev)
for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
INIT_LIST_HEAD(conf->temp_inactive_list + i);
+ atomic_set(&conf->r5c_cached_full_stripes, 0);
+ INIT_LIST_HEAD(&conf->r5c_full_stripe_list);
+ atomic_set(&conf->r5c_cached_partial_stripes, 0);
+ INIT_LIST_HEAD(&conf->r5c_partial_stripe_list);
+
conf->level = mddev->new_level;
conf->chunk_sectors = mddev->new_chunk_sectors;
if (raid5_alloc_percpu(conf) != 0)
@@ -7662,8 +7800,11 @@ static void raid5_quiesce(struct mddev *mddev, int state)
/* '2' tells resync/reshape to pause so that all
* active stripes can drain
*/
+ r5c_flush_cache(conf, 0);
conf->quiesce = 2;
wait_event_cmd(conf->wait_for_quiescent,
+ atomic_read(&conf->r5c_cached_partial_stripes) == 0 &&
+ atomic_read(&conf->r5c_cached_full_stripes) == 0 &&
atomic_read(&conf->active_stripes) == 0 &&
atomic_read(&conf->active_aligned_reads) == 0,
unlock_all_device_hash_locks_irq(conf),
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 517d4b6..71e67ba 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -226,6 +226,7 @@ struct stripe_head {
struct r5l_io_unit *log_io;
struct list_head log_list;
+ atomic_t dev_in_cache;
/**
* struct stripe_operations
* @target - STRIPE_OP_COMPUTE_BLK target
@@ -263,6 +264,7 @@ struct stripe_head_state {
*/
int syncing, expanding, expanded, replacing;
int locked, uptodate, to_read, to_write, failed, written;
+ int to_cache, want_cache, just_cached;
int to_fill, compute, req_compute, non_overwrite;
int failed_num[2];
int p_failed, q_failed;
@@ -313,6 +315,8 @@ enum r5dev_flags {
*/
R5_Discard, /* Discard the stripe */
R5_SkipCopy, /* Don't copy data from bio to stripe cache */
+ R5_Wantcache, /* Want write data to write cache */
+ R5_InCache, /* Data in cache */
};
/*
@@ -345,7 +349,13 @@ enum {
STRIPE_BITMAP_PENDING, /* Being added to bitmap, don't add
* to batch yet.
*/
- STRIPE_LOG_TRAPPED, /* trapped into log */
+ STRIPE_LOG_TRAPPED, /* trapped into log */
+ STRIPE_R5C_PARTIAL_STRIPE, /* in r5c cache (to-be/being handled or
+ * in conf->r5c_partial_stripe_list) */
+ STRIPE_R5C_FULL_STRIPE, /* in r5c cache (to-be/being handled or
+ * in conf->r5c_full_stripe_list) */
+ STRIPE_R5C_FROZEN, /* r5c_cache frozen and being written out */
+ STRIPE_R5C_WRITTEN, /* ready for r5c_handle_stripe_written() */
};
#define STRIPE_EXPAND_SYNC_FLAGS \
@@ -521,6 +531,12 @@ struct r5conf {
*/
atomic_t active_stripes;
struct list_head inactive_list[NR_STRIPE_HASH_LOCKS];
+
+ atomic_t r5c_cached_full_stripes;
+ struct list_head r5c_full_stripe_list;
+ atomic_t r5c_cached_partial_stripes;
+ struct list_head r5c_partial_stripe_list;
+
atomic_t empty_inactive_list_nr;
struct llist_head released_stripes;
wait_queue_head_t wait_for_quiescent;
@@ -635,4 +651,17 @@ extern void r5l_stripe_write_finished(struct stripe_head *sh);
extern int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio);
extern void r5l_quiesce(struct r5l_log *log, int state);
extern bool r5l_log_disk_error(struct r5conf *conf);
+extern void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
+extern int
+r5c_handle_stripe_dirtying(struct r5conf *conf, struct stripe_head *sh,
+ struct stripe_head_state *s, int disks);
+extern int r5c_cache_data(struct r5l_log *log, struct stripe_head *sh,
+ struct stripe_head_state *s);
+extern int r5c_cache_parity(struct r5l_log *log, struct stripe_head *sh,
+ struct stripe_head_state *s);
+extern void
+r5c_handle_stripe_written(struct r5conf *conf, struct stripe_head *sh);
+extern void r5c_freeze_stripe_for_reclaim(struct stripe_head *sh);
+extern void r5c_do_reclaim(struct r5conf *conf);
+extern int r5c_flush_cache(struct r5conf *conf, int num);
#endif
--
2.9.3
^ permalink raw reply related
* [PATCH v2 0/6] raid5-cache: enabling cache features
From: Song Liu @ 2016-09-26 23:30 UTC (permalink / raw)
To: linux-raid
Cc: neilb, shli, kernel-team, dan.j.williams, hch, liuzhengyuang521,
liuzhengyuan, Song Liu
These are the second version of patches to enable write cache part of
raid5-cache. The journal part was released with kernel 4.4.
The caching part uses same disk format of raid456 journal, and provides
acceleration to writes. Write operations are committed (bio_endio) once
the data is secured in journal. Reconstruct and RMW are postponed to
reclaim path, which is (hopefully) not on the critical path.
The changes are organized in 6 patches (details below).
Patch for chunk_aligned_read in earlier RFC is not included yet
(http://marc.info/?l=linux-raid&m=146432700719277). But we may still need
some optimizations later, especially for SSD raid devices.
Changes from PATCH v1 (http://marc.info/?l=linux-raid&m=147268192718851):
1. Improvements in reclaim patch
2. Fixed issue with bitmap
3. A fix by ZhengYuan Liu
Thanks,
Song
Song Liu (5):
r5cache: write part of r5cache
r5cache: sysfs entry r5c_state
r5cache: reclaim support
r5cache: r5c recovery
r5cache: handle SYNC and FUA
ZhengYuan Liu (1):
md/r5cache: decrease the counter after full-write stripe was reclaimed
drivers/md/raid5-cache.c | 1433 ++++++++++++++++++++++++++++++++++++++++------
drivers/md/raid5.c | 219 ++++++-
drivers/md/raid5.h | 71 ++-
3 files changed, 1508 insertions(+), 215 deletions(-)
--
2.9.3
^ permalink raw reply
* Re: Linux raid wiki
From: Wols Lists @ 2016-09-26 21:37 UTC (permalink / raw)
To: Phil Turmel, linux-raid
In-Reply-To: <33ee0032-11a7-3637-170a-a9da94c7bda9@turmel.org>
On 26/09/16 22:19, Phil Turmel wrote:
> On 09/26/2016 12:44 PM, Wols Lists wrote:
>> The next section -
>>
>> https://raid.wiki.kernel.org/index.php/Assemble_Run
>>
>> addresses what to do if the array is messed up in some way. Would you
>> mind taking a look at that now too :-)
>
> Hmmm. The last bit is less than ideal. If all drives are faulty, but
> runnable in the array with at least one drive of redundancy, the best
> way to put good drives in service is one-by-one mdadm --replace. That
> lets the redundancy fix any errors, and doesn't load down the problem
> drive any more than ddrescue would. And it has the benefit of
> increasing reliability as you go.
>
> If you don't have any redundancy left, then ddrescue of all readable
> drives is reasonable.
>
Which is the state this page is meant to cover. I'm assuming that if you
get this far, you have at an absolute minimum had to have done a
"--force --assemble" just to get a working array.
Each page has been intended to successively cover the state of the array
getting worse. The next page is "my metadata is trashed - mdadm says the
drive doesn't exist". I'm really not sure how to tackle that, but I know
there are several threads which cover damaged or trashed superblocks. I
think I'll just have to say "this is how you track down a GPT. This is
how you track down a superblock. This is how you interpret it. Get the
experts to help you put the array together again."
Cheers,
Wol
^ permalink raw reply
* Re: Linux raid wiki
From: Phil Turmel @ 2016-09-26 21:19 UTC (permalink / raw)
To: Wols Lists, linux-raid
In-Reply-To: <57E95054.4020903@youngman.org.uk>
On 09/26/2016 12:44 PM, Wols Lists wrote:
> The next section -
>
> https://raid.wiki.kernel.org/index.php/Assemble_Run
>
> addresses what to do if the array is messed up in some way. Would you
> mind taking a look at that now too :-)
Hmmm. The last bit is less than ideal. If all drives are faulty, but
runnable in the array with at least one drive of redundancy, the best
way to put good drives in service is one-by-one mdadm --replace. That
lets the redundancy fix any errors, and doesn't load down the problem
drive any more than ddrescue would. And it has the benefit of
increasing reliability as you go.
If you don't have any redundancy left, then ddrescue of all readable
drives is reasonable.
Phil
^ permalink raw reply
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