18 Dec, 2019
1 commit
-
commit 775d78319f1ceb32be8eb3b1202ccdc60e9cb7f1 upstream.
If pers->make_request fails in md_flush_request(), the bio is lost. To
fix this, pass back a bool to indicate if the original make_request call
should continue to handle the I/O and instead of assuming the flush logic
will push it to completion.Convert md_flush_request to return a bool and no longer calls the raid
driver's make_request function. If the return is true, then the md flush
logic has or will complete the bio and the md make_request call is done.
If false, then the md make_request function needs to keep processing like
it is a normal bio. Let the original call to md_handle_request handle any
need to retry sending the bio to the raid driver's make_request function
should it be needed.Also mark md_flush_request and the make_request function pointer as
__must_check to issue warnings should these critical return values be
ignored.Fixes: 2bc13b83e629 ("md: batch flush requests.")
Cc: stable@vger.kernel.org # # v4.19+
Cc: NeilBrown
Signed-off-by: David Jeffery
Reviewed-by: Xiao Ni
Signed-off-by: Song Liu
Signed-off-by: Greg Kroah-Hartman
29 Nov, 2019
1 commit
-
commit 45422b704db392a6d79d07ee3e3670b11048bd53 upstream.
Due to unneeded multiplication in the out_free_pages portion of
r10buf_pool_alloc(), when using a 3-copy raid10 layout, it is
possible to access a resync_pages offset that has not been
initialized. This access translates into a crash of the system
within resync_free_pages() while passing a bad pointer to
put_page(). Remove the multiplication, preventing access to the
uninitialized area.Fixes: f0250618361db ("md: raid10: don't use bio's vec table to manage resync pages")
Cc: stable@vger.kernel.org # 4.12+
Signed-off-by: John Pittman
Suggested-by: David Jeffery
Reviewed-by: Laurence Oberman
Signed-off-by: Song Liu
Signed-off-by: Greg Kroah-Hartman
08 Aug, 2019
2 commits
-
When the 'last' device in a RAID1 or RAID10 reports an error,
we do not mark it as failed. This would serve little purpose
as there is no risk of losing data beyond that which is obviously
lost (as there is with RAID5), and there could be other sectors
on the device which are readable, and only readable from this device.
This in general this maximises access to data.However the current implementation also stops an admin from removing
the last device by direct action. This is rarely useful, but in many
case is not harmful and can make automation easier by removing special
cases.Also, if an attempt to write metadata fails the device must be marked
as faulty, else an infinite loop will result, attempting to update
the metadata on all non-faulty devices.So add 'fail_last_dev' member to 'struct mddev', then we can bypasses
the 'last disk' checks for RAID1 and RAID10, and control the behavior
per array by change sysfs node.Signed-off-by: NeilBrown
[add sysfs node for fail_last_dev by Guoqing]
Signed-off-by: Guoqing Jiang
Signed-off-by: Song Liu -
Just like raid1, we do not queue write error bio to retry write
and acknowlege badblocks, when the device is faulty.Signed-off-by: Yufen Yu
Signed-off-by: Song Liu
15 Jun, 2019
4 commits
-
Andy reported that raid10 array with SSD disks has poor
read performance. Compared with raid1, RAID-1 can be 3x
faster than RAID-10 sometimes [1].The thing is that raid10 chooses the low distance disk
for read request, however, the approach doesn't work
well for SSD device since it doesn't have spindle like
HDD, we should just read from the SSD which has less
pending IO like commit 9dedf60313fa4 ("md/raid1: read
balance chooses idlest disk for SSD").So this commit selects the idlest SSD disk for read if
array has none rotational disk, otherwise, read_balance
uses the previous distance priority algorithm. With the
change, the performance of raid10 gets increased largely
per Andy's test [2].[1]. https://marc.info/?l=linux-raid&m=155915890004761&w=2
[2]. https://marc.info/?l=linux-raid&m=155990654223786&w=2Tested-by: Andy Smith
Signed-off-by: Guoqing Jiang
Signed-off-by: Song Liu
Signed-off-by: Jens Axboe -
Avoiding duplicated code, since they just execute a kfree.
Signed-off-by: Marcos Paulo de Souza
Signed-off-by: Jens Axboe -
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:struct foo {
int stuff;
struct boo entry[];
};instance = kmalloc(size, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva
Signed-off-by: Song Liu
Signed-off-by: Jens Axboe -
These definitions are being moved to raid1-10.c.
Signed-off-by: Marcos Paulo de Souza
Signed-off-by: Song Liu
Signed-off-by: Jens Axboe
24 May, 2019
1 commit
-
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 or at your option any
later version you should have received a copy of the gnu general
public license for example usr src linux copying if not write to the
free software foundation inc 675 mass ave cambridge ma 02139 usaextracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 20 file(s).
Signed-off-by: Thomas Gleixner
Reviewed-by: Allison Randal
Reviewed-by: Kate Stewart
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170858.552543146@linutronix.de
Signed-off-by: Greg Kroah-Hartman
13 Mar, 2019
2 commits
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mddev->sync_thread can be set to NULL on kzalloc failure downstream.
The patch checks for such a scenario and frees allocated resources.Committer node:
Added similar fix to raid5.c, as suggested by Guoqing.
Cc: stable@vger.kernel.org # v3.16+
Acked-by: Guoqing Jiang
Signed-off-by: Aditya Pakki
Signed-off-by: Song Liu -
In reshape_request it already adds len to sector_nr already. It's wrong to add len to
sector_nr again after adding pages to bio. If there is bad block it can't copy one chunk
at a time, it needs to goto read_more. Now the sector_nr is wrong. It can cause data
corruption.Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: Xiao Ni
Signed-off-by: Song Liu
21 Dec, 2018
2 commits
-
When both regular IO and resync IO happen at the same time,
and if we also need to split regular. Then we can see tasks
hang due to barrier.1. resync thread
[ 1463.757205] INFO: task md1_resync:5215 blocked for more than 480 seconds.
[ 1463.757207] Not tainted 4.19.5-1-default #1
[ 1463.757209] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1463.757212] md1_resync D 0 5215 2 0x80000000
[ 1463.757216] Call Trace:
[ 1463.757223] ? __schedule+0x29a/0x880
[ 1463.757231] ? raise_barrier+0x8d/0x140 [raid10]
[ 1463.757236] schedule+0x78/0x110
[ 1463.757243] raise_barrier+0x8d/0x140 [raid10]
[ 1463.757248] ? wait_woken+0x80/0x80
[ 1463.757257] raid10_sync_request+0x1f6/0x1e30 [raid10]
[ 1463.757265] ? _raw_spin_unlock_irq+0x22/0x40
[ 1463.757284] ? is_mddev_idle+0x125/0x137 [md_mod]
[ 1463.757302] md_do_sync.cold.78+0x404/0x969 [md_mod]
[ 1463.757311] ? wait_woken+0x80/0x80
[ 1463.757336] ? md_rdev_init+0xb0/0xb0 [md_mod]
[ 1463.757351] md_thread+0xe9/0x140 [md_mod]
[ 1463.757358] ? _raw_spin_unlock_irqrestore+0x2e/0x60
[ 1463.757364] ? __kthread_parkme+0x4c/0x70
[ 1463.757369] kthread+0x112/0x130
[ 1463.757374] ? kthread_create_worker_on_cpu+0x40/0x40
[ 1463.757380] ret_from_fork+0x3a/0x502. regular IO
[ 1463.760679] INFO: task kworker/0:8:5367 blocked for more than 480 seconds.
[ 1463.760683] Not tainted 4.19.5-1-default #1
[ 1463.760684] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1463.760687] kworker/0:8 D 0 5367 2 0x80000000
[ 1463.760718] Workqueue: md submit_flushes [md_mod]
[ 1463.760721] Call Trace:
[ 1463.760731] ? __schedule+0x29a/0x880
[ 1463.760741] ? wait_barrier+0xdd/0x170 [raid10]
[ 1463.760746] schedule+0x78/0x110
[ 1463.760753] wait_barrier+0xdd/0x170 [raid10]
[ 1463.760761] ? wait_woken+0x80/0x80
[ 1463.760768] raid10_write_request+0xf2/0x900 [raid10]
[ 1463.760774] ? wait_woken+0x80/0x80
[ 1463.760778] ? mempool_alloc+0x55/0x160
[ 1463.760795] ? md_write_start+0xa9/0x270 [md_mod]
[ 1463.760801] ? try_to_wake_up+0x44/0x470
[ 1463.760810] raid10_make_request+0xc1/0x120 [raid10]
[ 1463.760816] ? wait_woken+0x80/0x80
[ 1463.760831] md_handle_request+0x121/0x190 [md_mod]
[ 1463.760851] md_make_request+0x78/0x190 [md_mod]
[ 1463.760860] generic_make_request+0x1c6/0x470
[ 1463.760870] raid10_write_request+0x77a/0x900 [raid10]
[ 1463.760875] ? wait_woken+0x80/0x80
[ 1463.760879] ? mempool_alloc+0x55/0x160
[ 1463.760895] ? md_write_start+0xa9/0x270 [md_mod]
[ 1463.760904] raid10_make_request+0xc1/0x120 [raid10]
[ 1463.760910] ? wait_woken+0x80/0x80
[ 1463.760926] md_handle_request+0x121/0x190 [md_mod]
[ 1463.760931] ? _raw_spin_unlock_irq+0x22/0x40
[ 1463.760936] ? finish_task_switch+0x74/0x260
[ 1463.760954] submit_flushes+0x21/0x40 [md_mod]So resync io is waiting for regular write io to complete to
decrease nr_pending (conf->barrier++ is called before waiting).
The regular write io splits another bio after call wait_barrier
which call nr_pending++, then the splitted bio would continue
with raid10_write_request -> wait_barrier, so the splitted bio
has to wait for barrier to be zero, then deadlock happens as
follows.resync io regular io
raise_barrier
wait_barrier
generic_make_request
wait_barrierTo resolve the issue, we need to call allow_barrier to decrease
nr_pending before generic_make_request since regular IO is not
issued to underlying devices, and wait_barrier is called again
to ensure no internal IO happening.Fixes: fc9977dd069e ("md/raid10: simplify the splitting of requests.")
Reported-and-tested-by: Siniša Bandin
Signed-off-by: Guoqing Jiang
Signed-off-by: Shaohua Li -
Both raid10_read_request and raid10_write_request share
the same code at the beginning of them, so introduce
regular_request_wait to clean up code, and call it in
both request functions.Signed-off-by: Guoqing Jiang
Signed-off-by: Shaohua Li
19 Oct, 2018
3 commits
-
Since the resync region from suspend_info means one node
is reshaping this area, so the position of reshape_progress
should be included in the area.Reviewed-by: NeilBrown
Signed-off-by: Guoqing Jiang
Signed-off-by: Shaohua Li -
For clustered raid10 scenario, we need to let all the nodes
know about that a new disk is added to the array, and the
reshape caused by add new member just need to be happened in
one node, but other nodes should know about the change.Since reshape means read data from somewhere (which is already
used by array) and write data to unused region. Obviously, it
is awful if one node is reading data from address while another
node is writing to the same address. Considering we have
implemented suspend writes in the resyncing area, so we can
just broadcast the reading address to other nodes to avoid the
trouble.For master node, it would call reshape_request then update sb
during the reshape period. To avoid above trouble, we call
resync_info_update to send RESYNC message in reshape_request.Then from slave node's view, it receives two type messages:
1. RESYNCING message
Slave node add the address (where master node reading data from)
to suspend list.2. METADATA_UPDATED message
Once slave nodes know the reshaping is started in master node,
it is time to update reshape position and call start_reshape to
follow master node's step. After reshape is done, only reshape
position is need to be updated, so the majority task of reshaping
is happened on the master node.Reviewed-by: NeilBrown
Signed-off-by: Guoqing Jiang
Signed-off-by: Shaohua Li -
To support add disk under grow mode, we need to resize
all the bitmaps of each node before reshape, so that we
can ensure all nodes have the same view of the bitmap of
the clustered raid.So after the master node resized the bitmap, it broadcast
a message to other slave nodes, and it checks the size of
each bitmap are same or not by compare pages. We can only
continue the reshaping after all nodes update the bitmap
to the same size (by checking the pages), otherwise revert
bitmap size to previous value.The resize_bitmaps interface and BITMAP_RESIZE message are
introduced in md-cluster.c for the purpose.Reviewed-by: NeilBrown
Signed-off-by: Guoqing Jiang
Signed-off-by: Shaohua Li
15 Oct, 2018
1 commit
-
Commit d595567dc4f0 (MD: fix invalid stored role for a disk) broke linear
hotadd. Let's only fix the role for disks in raid1/10.
Based on Guoqing's original patch.Reported-by: kernel test robot
Cc: Gioh Kim
Cc: Guoqing Jiang
Signed-off-by: Shaohua Li
29 Sep, 2018
1 commit
-
[Symptom]
Resync thread hang when new added disk faulty during replacing.
[Root Cause]
In raid10_sync_request(), we expect to issue a bio with callback
end_sync_read(), and a bio with callback end_sync_write().In normal situation, we will add resyncing sectors into
mddev->recovery_active when raid10_sync_request() returned, and sub
resynced sectors from mddev->recovery_active when end_sync_write()
calls end_sync_request().If new added disk, which are replacing the old disk, is set faulty,
there is a race condition:
1. In the first rcu protected section, resync thread did not detect
that mreplace is set faulty and pass the condition.
2. In the second rcu protected section, mreplace is set faulty.
3. But, resync thread will prepare the read object first, and then
check the write condition.
4. It will find that mreplace is set faulty and do not have to
prepare write object.
This cause we add resync sectors but never sub it.[How to Reproduce]
This issue can be easily reproduced by the following steps:
mdadm -C /dev/md0 --assume-clean -l 10 -n 4 /dev/sd[abcd]
mdadm /dev/md0 -a /dev/sde
mdadm /dev/md0 --replace /dev/sdd
sleep 1
mdadm /dev/md0 -f /dev/sde[How to Fix]
This issue can be fixed by using local variables to record the result
of test conditions. Once the conditions are satisfied, we can make sure
that we need to issue a bio for read and a bio for write.Previous 'commit 24afd80d99f8 ("md/raid10: handle recovery of
replacement devices.")' will also check whether bio is NULL, but leave
the comment saying that it is a pointless test. So we remove this dummy
check.Reported-by: Alex Chen
Reviewed-by: Allen Peng
Reviewed-by: BingJing Chang
Signed-off-by: Alex Wu
Signed-off-by: Shaohua Li
01 Sep, 2018
1 commit
-
In raid10 reshape_request it gets max_sectors in read_balance. If the underlayer disks
have bad blocks, the max_sectors is less than last. It will call goto read_more many
times. It calls raise_barrier(conf, sectors_done != 0) every time. In this condition
sectors_done is not 0. So the value passed to the argument force of raise_barrier is
true.In raise_barrier it checks conf->barrier when force is true. If force is true and
conf->barrier is 0, it panic. In this case reshape_request submits bio to under layer
disks. And in the callback function of the bio it calls lower_barrier. If the bio
finishes before calling raise_barrier again, it can trigger the BUG_ON.Add one pair of raise_barrier/lower_barrier to fix this bug.
Signed-off-by: Xiao Ni
Suggested-by: Neil Brown
Signed-off-by: Shaohua Li
19 Aug, 2018
1 commit
-
Pull input updates from Dmitry Torokhov:
- a new driver for Rohm BU21029 touch controller
- new bitmap APIs: bitmap_alloc, bitmap_zalloc and bitmap_free
- updates to Atmel, eeti. pxrc and iforce drivers
- assorted driver cleanups and fixes.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (57 commits)
MAINTAINERS: Add PhoenixRC Flight Controller Adapter
Input: do not use WARN() in input_alloc_absinfo()
Input: mark expected switch fall-throughs
Input: raydium_i2c_ts - use true and false for boolean values
Input: evdev - switch to bitmap API
Input: gpio-keys - switch to bitmap_zalloc()
Input: elan_i2c_smbus - cast sizeof to int for comparison
bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap_free()
md: Avoid namespace collision with bitmap API
dm: Avoid namespace collision with bitmap API
Input: pm8941-pwrkey - add resin entry
Input: pm8941-pwrkey - abstract register offsets and event code
Input: iforce - reorganize joystick configuration lists
Input: atmel_mxt_ts - move completion to after config crc is updated
Input: atmel_mxt_ts - don't report zero pressure from T9
Input: atmel_mxt_ts - zero terminate config firmware file
Input: atmel_mxt_ts - refactor config update code to add context struct
Input: atmel_mxt_ts - config CRC may start at T71
Input: atmel_mxt_ts - remove unnecessary debug on ENOMEM
Input: atmel_mxt_ts - remove duplicate setup of ABS_MT_PRESSURE
...
02 Aug, 2018
1 commit
-
bitmap API (include/linux/bitmap.h) has 'bitmap' prefix for its methods.
On the other hand MD bitmap API is special case.
Adding 'md' prefix to it to avoid name space collision.No functional changes intended.
Signed-off-by: Andy Shevchenko
Acked-by: Shaohua Li
Signed-off-by: Dmitry Torokhov
29 Jun, 2018
1 commit
-
During assemble, the spare marked for replacement is not checked.
conf->fullsync cannot be updated to be 1. As a result, recovery will
treat it as a clean array. All recovering sectors are skipped. Original
device is replaced with the not-recovered spare.mdadm -C /dev/md0 -l10 -n4 -pn2 /dev/loop[0123]
mdadm /dev/md0 -a /dev/loop4
mdadm /dev/md0 --replace /dev/loop0
mdadm -S /dev/md0 # stop array during recoverymdadm -A /dev/md0 /dev/loop[01234]
After reassemble, you can see recovery go on, but it completes
immediately. In fact, recovery is not actually processed.To solve this problem, we just add the missing logics for replacment
spares. (In raid1.c or raid5.c, they have already been checked.)Reported-by: Alex Chen
Reviewed-by: Alex Wu
Reviewed-by: Chung-Chiang Cheng
Signed-off-by: BingJing Chang
Signed-off-by: Shaohua Li
13 Jun, 2018
2 commits
-
The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:kzalloc(a * b, gfp)
with:
kcalloc(a * b, gfp)as well as handling cases of:
kzalloc(a * b * c, gfp)
with:
kzalloc(array3_size(a, b, c), gfp)
as it's slightly less ugly than:
kzalloc_array(array_size(a, b), c, gfp)
This does, however, attempt to ignore constant size factors like:
kzalloc(4 * 1024, gfp)
though any constants defined via macros get caught up in the conversion.
Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.The Coccinelle script used for this was:
// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)Signed-off-by: Kees Cook
-
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:kmalloc(a * b, gfp)
with:
kmalloc_array(a * b, gfp)as well as handling cases of:
kmalloc(a * b * c, gfp)
with:
kmalloc(array3_size(a, b, c), gfp)
as it's slightly less ugly than:
kmalloc_array(array_size(a, b), c, gfp)
This does, however, attempt to ignore constant size factors like:
kmalloc(4 * 1024, gfp)
though any constants defined via macros get caught up in the conversion.
Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().The Coccinelle script used for this was:
// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@(
kmalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kmalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@(
kmalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@(
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@- kmalloc
+ kmalloc_array
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@(
kmalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@(
kmalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@(
kmalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@(
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@(
kmalloc(sizeof(THING) * C2, ...)
|
kmalloc(sizeof(TYPE) * C2, ...)
|
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * E2
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- E1 * E2
+ E1, E2
, ...)
)Signed-off-by: Kees Cook
10 Jun, 2018
1 commit
-
Pull MD updates from Shaohua Li:
"A few fixes of MD for this merge window. Mostly bug fixes:- raid5 stripe batch fix from Amy
- Read error handling for raid1 FailFast device from Gioh
- raid10 recovery NULL pointer dereference fix from Guoqing
- Support write hint for raid5 stripe cache from Mariusz
- Fixes for device hot add/remove from Neil and Yufen
- Improve flush bio scalability from Xiao"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
MD: fix lock contention for flush bios
md/raid5: Assigning NULL to sh->batch_head before testing bit R5_Overlap of a stripe
md/raid1: add error handling of read error from FailFast device
md: fix NULL dereference of mddev->pers in remove_and_add_spares()
raid5: copy write hint from origin bio to stripe
md: fix two problems with setting the "re-add" device state.
raid10: check bio in r10buf_pool_free to void NULL pointer dereference
md: fix an error code format and remove unsed bio_sector
31 May, 2018
1 commit
-
Convert md to embedded bio sets.
Signed-off-by: Kent Overstreet
Signed-off-by: Jens Axboe
02 May, 2018
2 commits
-
For recovery case, r10buf_pool_alloc only allocates 2 bios,
so we can't access more than 2 bios in r10buf_pool_free.
Otherwise, we can see NULL pointer dereference as follows:[ 98.347009] BUG: unable to handle kernel NULL pointer dereference
at 0000000000000050
[ 98.355783] IP: r10buf_pool_free+0x38/0xe0 [raid10]
[...]
[ 98.543734] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 98.550161] CR2: 0000000000000050 CR3: 000000089500a001 CR4: 00000000001606f0
[ 98.558145] Call Trace:
[ 98.560881]
[ 98.563136] put_buf+0x19/0x20 [raid10]
[ 98.567426] end_sync_request+0x6b/0x70 [raid10]
[ 98.572591] end_sync_write+0x9b/0x160 [raid10]
[ 98.577662] blk_update_request+0x78/0x2c0
[ 98.582254] scsi_end_request+0x2c/0x1e0 [scsi_mod]
[ 98.587719] scsi_io_completion+0x22f/0x610 [scsi_mod]
[ 98.593472] blk_done_softirq+0x8e/0xc0
[ 98.597767] __do_softirq+0xde/0x2b3
[ 98.601770] irq_exit+0xae/0xb0
[ 98.605285] do_IRQ+0x81/0xd0
[ 98.608606] common_interrupt+0x7d/0x7d
[ 98.612898]So we need to check the bio is valid or not before the bio is
used in r10buf_pool_free. Another workable way is to free 2 bios
for recovery case just like r10buf_pool_alloc.Fixes: f0250618361d ("md: raid10: don't use bio's vec table to manage resync pages")
Reported-by: Alexis Castilla
Tested-by: Alexis Castilla
Signed-off-by: Guoqing Jiang
Signed-off-by: Shaohua Li -
Signed-off-by: Yufen Yu
Signed-off-by: Shaohua Li
06 Apr, 2018
1 commit
-
Pull block layer updates from Jens Axboe:
"It's a pretty quiet round this time, which is nice. This contains:- series from Bart, cleaning up the way we set/test/clear atomic
queue flags.- series from Bart, fixing races between gendisk and queue
registration and removal.- set of bcache fixes and improvements from various folks, by way of
Michael Lyle.- set of lightnvm updates from Matias, most of it being the 1.2 to
2.0 transition.- removal of unused DIO flags from Nikolay.
- blk-mq/sbitmap memory ordering fixes from Omar.
- divide-by-zero fix for BFQ from Paolo.
- minor documentation patches from Randy.
- timeout fix from Tejun.
- Alpha "can't write a char atomically" fix from Mikulas.
- set of NVMe fixes by way of Keith.
- bsg and bsg-lib improvements from Christoph.
- a few sed-opal fixes from Jonas.
- cdrom check-disk-change deadlock fix from Maurizio.
- various little fixes, comment fixes, etc from various folks"
* tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block: (139 commits)
blk-mq: Directly schedule q->timeout_work when aborting a request
blktrace: fix comment in blktrace_api.h
lightnvm: remove function name in strings
lightnvm: pblk: remove some unnecessary NULL checks
lightnvm: pblk: don't recover unwritten lines
lightnvm: pblk: implement 2.0 support
lightnvm: pblk: implement get log report chunk
lightnvm: pblk: rename ppaf* to addrf*
lightnvm: pblk: check for supported version
lightnvm: implement get log report chunk helpers
lightnvm: make address conversions depend on generic device
lightnvm: add support for 2.0 address format
lightnvm: normalize geometry nomenclature
lightnvm: complete geo structure with maxoc*
lightnvm: add shorten OCSSD version in geo
lightnvm: add minor version to generic geometry
lightnvm: simplify geometry structure
lightnvm: pblk: refactor init/exit sequences
lightnvm: Avoid validation of default op value
lightnvm: centralize permission check for lightnvm ioctl
...
09 Mar, 2018
1 commit
-
This patch has been generated as follows:
for verb in set_unlocked clear_unlocked set clear; do
replace-in-files queue_flag_${verb} blk_queue_flag_${verb%_unlocked} \
$(git grep -lw queue_flag_${verb} drivers block/bsg*)
doneExcept for protecting all queue flag changes with the queue lock
this patch does not change any functionality.Cc: Mike Snitzer
Cc: Shaohua Li
Cc: Christoph Hellwig
Cc: Hannes Reinecke
Cc: Ming Lei
Signed-off-by: Bart Van Assche
Reviewed-by: Martin K. Petersen
Reviewed-by: Johannes Thumshirn
Acked-by: Martin K. Petersen
Signed-off-by: Jens Axboe
26 Feb, 2018
2 commits
-
There is a potential deadlock if mount/umount happens when
raid5_finish_reshape() tries to grow the size of emulated disk.How the deadlock happens?
1) The raid5 resync thread finished reshape (expanding array).
2) The mount or umount thread holds VFS sb->s_umount lock and tries to
write through critical data into raid5 emulated block device. So it
waits for raid5 kernel thread handling stripes in order to finish it
I/Os.
3) In the routine of raid5 kernel thread, md_check_recovery() will be
called first in order to reap the raid5 resync thread. That is,
raid5_finish_reshape() will be called. In this function, it will try
to update conf and call VFS revalidate_disk() to grow the raid5
emulated block device. It will try to acquire VFS sb->s_umount lock.
The raid5 kernel thread cannot continue, so no one can handle mount/
umount I/Os (stripes). Once the write-through I/Os cannot be finished,
mount/umount will not release sb->s_umount lock. The deadlock happens.The raid5 kernel thread is an emulated block device. It is responible to
handle I/Os (stripes) from upper layers. The emulated block device
should not request any I/Os on itself. That is, it should not call VFS
layer functions. (If it did, it will try to acquire VFS locks to
guarantee the I/Os sequence.) So we have the resync thread to send
resync I/O requests and to wait for the results.For solving this potential deadlock, we can put the size growth of the
emulated block device as the final step of reshape thread.2017/12/29:
Thanks to Guoqing Jiang ,
we confirmed that there is the same deadlock issue in raid10. It's
reproducible and can be fixed by this patch. For raid10.c, we can remove
the similar code to prevent deadlock as well since they has been called
before.Reported-by: Alex Wu
Reviewed-by: Alex Wu
Reviewed-by: Chung-Chiang Cheng
Signed-off-by: BingJing Chang
Signed-off-by: Shaohua Li -
r10conf is already successfully allocated before checking the layout
Signed-off-by: Lidong Zhong
Reviewed-by: Guoqing Jiang
Signed-off-by: Shaohua Li
20 Feb, 2018
1 commit
-
In the case of 'recover', an r10bio with R10BIO_WriteError &
R10BIO_IsRecover will be progressed by handle_write_completed().
This function traverses all r10bio->devs[copies].
If devs[m].repl_bio != NULL, it thinks conf->mirrors[dev].replacement
is also not NULL. However, this is not always true.When there is an rdev of raid10 has replacement, then each r10bio
->devs[m].repl_bio != NULL in conf->r10buf_pool. However, in 'recover',
even if corresponded replacement is NULL, it doesn't clear r10bio
->devs[m].repl_bio, resulting in replacement NULL deference.This bug was introduced when replacement support for raid10 was
added in Linux 3.3.As NeilBrown suggested:
Elsewhere the determination of "is this device part of the
resync/recovery" is made by resting bio->bi_end_io.
If this is end_sync_write, then we tried to write here.
If it is NULL, then we didn't try to write.Fixes: 9ad1aefc8ae8 ("md/raid10: Handle replacement devices during resync.")
Cc: stable (V3.3+)
Suggested-by: NeilBrown
Signed-off-by: Yufen Yu
Signed-off-by: Shaohua Li
18 Feb, 2018
1 commit
-
To align with raid1's resync window, we need to
set the resync window of raid10 to 32M as well.Fixes: 8db87912c9a8 ("md-cluster: Use a small window for raid10 resync")
Reported-by: Zhilong Liu
Signed-off-by: Guoqing Jiang
Signed-off-by: Shaohua Li
12 Dec, 2017
1 commit
-
If you prepare_to_wait() after a previous prepare_to_wait(),
but before calling schedule(), you get warning:do not call blocking ops when !TASK_RUNNING; state=2
This is appropriate as it is often a bug. The event that the
first prepare_to_wait() expects might wake up the schedule following
the second prepare_to_wait(), which could be confusing.However if both prepare_to_wait()s are part of simple wait_event()
loops, and if the inner one is rarely called, then there is
no problem. The inner loop is too simple to get confused by
a stray wakeup, and the outer loop won't spin unduly because the
inner doesnt affect it often.This pattern occurs in both raid1.c and raid10.c in the use of
flush_pending_writes().The warning can be silenced by setting current->state to TASK_RUNNING.
Signed-off-by: NeilBrown
Signed-off-by: Shaohua Li
02 Dec, 2017
1 commit
-
flush_pending_writes isn't always called with block plug, so add it, and plug
works in nested way.Signed-off-by: Shaohua Li
02 Nov, 2017
4 commits
-
Suspending the entire device for resync could take
too long. Resync in small chunks.cluster's resync window is maintained in r10conf as
cluster_sync_low and cluster_sync_high, and processed
in raid10's sync_request(). If the current resync is
outside the cluster resync window:1. Set the cluster_sync_low to curr_resync_completed.
2. Set cluster_sync_high to cluster_sync_low + stripe
size.
3. Send a message to all nodes so they may add it in
their suspension list.Note:
We only support "near" raid10 so far, resync a far or
offset raid10 array could have trouble. So raid10_run
checks the layout of clustered raid10, it will refuse
to run if the layout is not correct.With the "near" layout we process one stripe at a time
progressing monotonically through the address space.
So we can have a sliding window of whole-stripes which
moves through the array suspending IO on other nodes,
and both resync which uses array addresses and recovery
which uses device addresses can stay within this window.Signed-off-by: Guoqing Jiang
Signed-off-by: Shaohua Li -
If there is a resync going on, all nodes must suspend
writes to the range. This is recorded in suspend_info
and suspend_list.If there is an I/O within the ranges of any of the
suspend_info, area_resyncing will return 1.Signed-off-by: Guoqing Jiang
Signed-off-by: Shaohua Li -
Just like clustered raid1, it is impossible for cluster raid10
to choose the best device for read balance when the area of
array is resyncing. Because we cannot trust the data to be the
same on all devices at that time, so we choose just the first
one to use, so set do_balance to 0.Signed-off-by: Guoqing Jiang
Signed-off-by: Shaohua Li -
The '2' argument means "wake up anything that is waiting".
This is an inelegant part of the design and was added
to help support management of suspend_lo/suspend_hi setting.
Now that suspend_lo/hi is managed in mddev_suspend/resume,
that need is gone.
These is still a couple of places where we call 'quiesce'
with an argument of '2', but they can safely be changed to
call ->quiesce(.., 1); ->quiesce(.., 0) which
achieve the same result at the small cost of pausing IO
briefly.This removes a small "optimization" from suspend_{hi,lo}_store,
but it isn't clear that optimization served a useful purpose.
The code now is a lot clearer.Suggested-by: Shaohua Li
Signed-off-by: NeilBrown
Signed-off-by: Shaohua Li