Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
1 年多 前同步成功

通知 163
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 18 3月, 2020 2 次提交
    • X
      alinux: jbd2: track slow handle which is preventing transaction committing · 83cd9d23
      由 Xiaoguang Wang 提交于 
      While transaction is going to commit, it first sets its state to be
T_LOCKED and waits all outstanding handles to complete, and the
committing transaction will always be in locked state so long as it
has outstanding handles, also the whole fs will be locked and all later
fs modification operations will be stucked in wait_transaction_locked().

It's hard to tell why handles are that slow, so here we add a new staic
tracepoint to track such slow handle, and show io wait time and sched
wait time, output likes below:
  fsstress-20347 [024] ....  1570.305454: jbd2_slow_handle_stats: dev 254,17
tid 15853 type 4 line_no 3101 interval 126 sync 0 requested_blocks 24
dirtied_blocks 0 trans_wait 122 space_wait 0 sched_wait 0 io_wait 126

"trans_wait 122" means that this current committing transaction has been
locked for 122ms, due to this handle is not completed quickly.

From "io_wait 126", we can see that io is the major reason.

In this patch, we also add a per fs control file used to determine
whether a handle can be considered to be slow.
    /proc/fs/jbd2/vdb1-8/stall_thresh
default value is 100ms, users can set new threshold by echoing new value
to this file.

Later I also plan to add a proc file fs per fs to record these info.
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
      83cd9d23
    • X
      alinux: fs: record page or bio info while process is waitting on it · 2864376f
      由 Xiaoguang Wang 提交于 
      If one process context is stucked in wait_on_buffer(), lock_buffer(),
lock_page() and wait_on_page_writeback() and wait_on_bit_io(), it's
hard to tell ture reason, for example, whether this page is under io,
or this page is just locked too long by other process context.

Normally io request has multiple bios, and every bio contains multiple
pages which will hold data to be read from or written to device, so here
we record page info or bio info in task_struct while process calls
lock_page(), lock_buffer(), wait_on_page_writeback(), wait_on_buffer()
and wait_on_bit_io(), we add a new proce interface:
[lege@localhost linux]$ cat /proc/4516/wait_res
1 ffffd0969f95d3c0 4295369599 4295381596

Above info means that thread 4516 is waitting on a page, address is
ffffd0969f95d3c0, and has waited for 11997ms.

First field denotes the page address process is waitting on.
Second field denotes the wait moment and the third denotes current moment.

In practice, if we found a process waitting on one page for too long time,
we can get page's address by reading /proc/$pid/wait_page, and search this
page address in all block devices' /sys/kernel/debug/block/${devname}/rq_hang,
if search operation hits one, we can get the request and know why this io
request hangs that long.
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
      2864376f
  3. 17 1月, 2020 2 次提交
  5. 15 1月, 2020 3 次提交
    • X
      alinux: jbd2: add proc entry to control whether doing buffer copy-out · 1ced8a5c
      由 Xiaoguang Wang 提交于 
      When jbd2 tries to get write access to one buffer, and if this buffer
is under writeback with BH_Shadow flag, jbd2 will wait until this buffer
has been written to disk, but sometimes the time taken to wait may be
much long, especially disk capacity is almost full.

Here add a proc entry "force-copy", if its value is not zero, jbd2 will
always do meta buffer copy-cout, then we can eliminate the unnecessary
wating time here, and reduce long tail latency for buffered-write.

I construct such test case below:

$cat offline.fio
; fio-rand-RW.job for fiotest

[global]
name=fio-rand-RW
filename=fio-rand-RW
rw=randrw
rwmixread=60
rwmixwrite=40
bs=4K
direct=0
numjobs=4
time_based=1
runtime=900

[file1]
size=60G
ioengine=sync
iodepth=16

$cat online.fio
; fio-seq-write.job for fiotest

[global]
name=fio-seq-write
filename=fio-seq-write
rw=write
bs=256K
direct=0
numjobs=1
time_based=1
runtime=60

[file1]
rate=50m
size=10G
ioengine=sync
iodepth=16

With this patch:
$cat /proc/fs/jbd2/sda5-8/force_copy
0

online fio almost always get such long tail latency:

Jobs: 1 (f=1), 0B/s-0B/s: [W(1)][100.0%][w=50.0MiB/s][w=200 IOPS][eta
00m:00s]
file1: (groupid=0, jobs=1): err= 0: pid=17855: Thu Nov 15 09:45:57 2018
  write: IOPS=200, BW=50.0MiB/s (52.4MB/s)(3000MiB/60001msec)
    clat (usec): min=135, max=4086.6k, avg=867.21, stdev=50338.22
     lat (usec): min=139, max=4086.6k, avg=871.16, stdev=50338.22
    clat percentiles (usec):
     |  1.00th=[    141],  5.00th=[    143], 10.00th=[    145],
     | 20.00th=[    147], 30.00th=[    147], 40.00th=[    149],
     | 50.00th=[    149], 60.00th=[    151], 70.00th=[    153],
     | 80.00th=[    155], 90.00th=[    159], 95.00th=[    163],
     | 99.00th=[    255], 99.50th=[    273], 99.90th=[    429],
     | 99.95th=[    441], 99.99th=[3640656]

$cat /proc/fs/jbd2/sda5-8/force_copy
1

online fio latency is much better.

Jobs: 1 (f=1), 0B/s-0B/s: [W(1)][100.0%][w=50.0MiB/s][w=200 IOPS][eta
00m:00s]
file1: (groupid=0, jobs=1): err= 0: pid=8084: Thu Nov 15 09:31:15 2018
  write: IOPS=200, BW=50.0MiB/s (52.4MB/s)(3000MiB/60001msec)
    clat (usec): min=137, max=545, avg=151.35, stdev=16.22
     lat (usec): min=140, max=548, avg=155.31, stdev=16.65
    clat percentiles (usec):
     |  1.00th=[  143],  5.00th=[  145], 10.00th=[  145], 20.00th=[
147],
     | 30.00th=[  147], 40.00th=[  147], 50.00th=[  149], 60.00th=[
149],
     | 70.00th=[  151], 80.00th=[  155], 90.00th=[  157], 95.00th=[
161],
     | 99.00th=[  239], 99.50th=[  269], 99.90th=[  420], 99.95th=[
429],
     | 99.99th=[  537]

As to the cost: because we'll always need to copy meta buffer, will
consume minor cpu time and some memory(at most 32MB for 128MB journal
size).
Signed-off-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Reviewed-by: NLiu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
      1ced8a5c
    • X
      alinux: jbd2: add new "stats" proc file · 7e2e7b9a
      由 Xiaoguang Wang 提交于 
      /proc/fs/jbd2/${device}/info only shows whole average statistical
info about jbd2's life cycle, but it can not show jbd2 info in
specified time interval and sometimes this capability is very useful
for trouble shooting. For example, we can not see how rs_locked and
rs_flushing grows in specified time interval, but these two indexes
can explain some reasons for app's behaviours.

Here we add a new "stats" proc file like /proc/diskstats, then we can
implement a simple tool jbd2_stats which'll display detailed jbd2 info
in specified time interval. Like below(time interval 5s):

[lege@localhost ~]$ cat /proc/fs/jbd2/vdb1-8/stats
51 30 8192 0 1 241616 0 0 22 0 47158 891 942 1000 1000

[lege@localhost ~]$ gcc -o jbd2_stat jbd2_stat.c ; ./jbd2_stat

Device              tid     trans   handles    locked  flushing
logging
vdb1-8             1861       158       359     13.00      0.00
2.00

Device              tid     trans   handles    locked  flushing
logging
vdb1-8             1974       113       389     26.00      0.00
5.00

Device              tid     trans   handles    locked  flushing
logging
vdb1-8             2188       214       308     10.00      0.00
7.00

Device              tid     trans   handles    locked  flushing
logging
vdb1-8             2344       156       332     19.00      0.00
4.00
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: NLiu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
      7e2e7b9a
    • J
      alinux: jbd2: create jbd2-ckpt thread for journal checkpoint · 3999cdd9
      由 Joseph Qi 提交于 
      This is trying to do jbd2 checkpoint in a specific kernel thread, then
checkpoint won't be under io throttle control.
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: NJiufei Xue <jiufei.xue@linux.alibaba.com>
Signed-off-by: Nzhangliguang <zhangliguang@linux.alibaba.com>
Reviewed by: Baoyou Xie <baoyou.xie@linux.alibaba.com>
Reviewed-by: NLiu Bo <bo.liu@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
      3999cdd9
  7. 27 12月, 2019 1 次提交
  9. 28 7月, 2019 1 次提交
    • R
      jbd2: introduce jbd2_inode dirty range scoping · af3812b6
      由 Ross Zwisler 提交于 
      commit 6ba0e7dc64a5adcda2fbe65adc466891795d639e upstream.

Currently both journal_submit_inode_data_buffers() and
journal_finish_inode_data_buffers() operate on the entire address space
of each of the inodes associated with a given journal entry.  The
consequence of this is that if we have an inode where we are constantly
appending dirty pages we can end up waiting for an indefinite amount of
time in journal_finish_inode_data_buffers() while we wait for all the
pages under writeback to be written out.

The easiest way to cause this type of workload is do just dd from
/dev/zero to a file until it fills the entire filesystem.  This can
cause journal_finish_inode_data_buffers() to wait for the duration of
the entire dd operation.

We can improve this situation by scoping each of the inode dirty ranges
associated with a given transaction.  We do this via the jbd2_inode
structure so that the scoping is contained within jbd2 and so that it
follows the lifetime and locking rules for that structure.

This allows us to limit the writeback & wait in
journal_submit_inode_data_buffers() and
journal_finish_inode_data_buffers() respectively to the dirty range for
a given struct jdb2_inode, keeping us from waiting forever if the inode
in question is still being appended to.
Signed-off-by: NRoss Zwisler <zwisler@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      af3812b6
  11. 22 5月, 2019 2 次提交
  13. 06 4月, 2019 2 次提交
    • T
      jbd2: fix race when writing superblock · 91544201
      由 Theodore Ts'o 提交于 
      [ Upstream commit 538bcaa6261b77e71d37f5596c33127c1a3ec3f7 ]

The jbd2 superblock is lockless now, so there is probably a race
condition between writing it so disk and modifing contents of it, which
may lead to checksum error. The following race is the one case that we
have captured.

jbd2                                fsstress
jbd2_journal_commit_transaction
 jbd2_journal_update_sb_log_tail
  jbd2_write_superblock
   jbd2_superblock_csum_set         jbd2_journal_revoke
                                     jbd2_journal_set_features(revork)
                                     modify superblock
   submit_bh(checksum incorrect)

Fix this by locking the buffer head before modifing it.  We always
write the jbd2 superblock after we modify it, so this just means
calling the lock_buffer() a little earlier.

This checksum corruption problem can be reproduced by xfstests
generic/475.
Reported-by: Nzhangyi (F) <yi.zhang@huawei.com>
Suggested-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      91544201
    • L
      jbd2: fix invalid descriptor block checksum · 6a817a7a
      由 luojiajun 提交于 
      [ Upstream commit 6e876c3dd205d30b0db6850e97a03d75457df007 ]

In jbd2_journal_commit_transaction(), if we are in abort mode,
we may flush the buffer without setting descriptor block checksum
by goto start_journal_io. Then fs is mounted,
jbd2_descriptor_block_csum_verify() failed.

[  271.379811] EXT4-fs (vdd): shut down requested (2)
[  271.381827] Aborting journal on device vdd-8.
[  271.597136] JBD2: Invalid checksum recovering block 22199 in log
[  271.598023] JBD2: recovery failed
[  271.598484] EXT4-fs (vdd): error loading journal

Fix this problem by keep setting descriptor block checksum if the
descriptor buffer is not NULL.

This checksum problem can be reproduced by xfstests generic/388.
Signed-off-by: Nluojiajun <luojiajun3@huawei.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      6a817a7a
  15. 24 3月, 2019 2 次提交
    • Z
      jbd2: fix compile warning when using JBUFFER_TRACE · 584f390d
      由 zhangyi (F) 提交于 
      commit 01215d3edb0f384ddeaa5e4a22c1ae5ff634149f upstream.

The jh pointer may be used uninitialized in the two cases below and the
compiler complain about it when enabling JBUFFER_TRACE macro, fix them.

In file included from fs/jbd2/transaction.c:19:0:
fs/jbd2/transaction.c: In function ‘jbd2_journal_get_undo_access’:
./include/linux/jbd2.h:1637:38: warning: ‘jh’ is used uninitialized in this function [-Wuninitialized]
 #define JBUFFER_TRACE(jh, info) do { printk("%s: %d\n", __func__, jh->b_jcount);} while (0)
                                      ^
fs/jbd2/transaction.c:1219:23: note: ‘jh’ was declared here
  struct journal_head *jh;
                       ^
In file included from fs/jbd2/transaction.c:19:0:
fs/jbd2/transaction.c: In function ‘jbd2_journal_dirty_metadata’:
./include/linux/jbd2.h:1637:38: warning: ‘jh’ may be used uninitialized in this function [-Wmaybe-uninitialized]
 #define JBUFFER_TRACE(jh, info) do { printk("%s: %d\n", __func__, jh->b_jcount);} while (0)
                                      ^
fs/jbd2/transaction.c:1332:23: note: ‘jh’ was declared here
  struct journal_head *jh;
                       ^
Signed-off-by: Nzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      584f390d
    • Z
      jbd2: clear dirty flag when revoking a buffer from an older transaction · dbe4bc99
      由 zhangyi (F) 提交于 
      commit 904cdbd41d749a476863a0ca41f6f396774f26e4 upstream.

Now, we capture a data corruption problem on ext4 while we're truncating
an extent index block. Imaging that if we are revoking a buffer which
has been journaled by the committing transaction, the buffer's jbddirty
flag will not be cleared in jbd2_journal_forget(), so the commit code
will set the buffer dirty flag again after refile the buffer.

fsx                               kjournald2
                                  jbd2_journal_commit_transaction
jbd2_journal_revoke                commit phase 1~5...
 jbd2_journal_forget
   belongs to older transaction    commit phase 6
   jbddirty not clear               __jbd2_journal_refile_buffer
                                     __jbd2_journal_unfile_buffer
                                      test_clear_buffer_jbddirty
                                       mark_buffer_dirty

Finally, if the freed extent index block was allocated again as data
block by some other files, it may corrupt the file data after writing
cached pages later, such as during unmount time. (In general,
clean_bdev_aliases() related helpers should be invoked after
re-allocation to prevent the above corruption, but unfortunately we
missed it when zeroout the head of extra extent blocks in
ext4_ext_handle_unwritten_extents()).

This patch mark buffer as freed and set j_next_transaction to the new
transaction when it already belongs to the committing transaction in
jbd2_journal_forget(), so that commit code knows it should clear dirty
bits when it is done with the buffer.

This problem can be reproduced by xfstests generic/455 easily with
seeds (3246 3247 3248 3249).
Signed-off-by: Nzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      dbe4bc99
  17. 14 11月, 2018 1 次提交
    • J
      jbd2: fix use after free in jbd2_log_do_checkpoint() · 25881163
      由 Jan Kara 提交于 
      commit ccd3c4373eacb044eb3832966299d13d2631f66f upstream.

The code cleaning transaction's lists of checkpoint buffers has a bug
where it increases bh refcount only after releasing
journal->j_list_lock. Thus the following race is possible:

CPU0					CPU1
jbd2_log_do_checkpoint()
					jbd2_journal_try_to_free_buffers()
					  __journal_try_to_free_buffer(bh)
  ...
  while (transaction->t_checkpoint_io_list)
  ...
    if (buffer_locked(bh)) {

<-- IO completes now, buffer gets unlocked -->

      spin_unlock(&journal->j_list_lock);
					    spin_lock(&journal->j_list_lock);
					    __jbd2_journal_remove_checkpoint(jh);
					    spin_unlock(&journal->j_list_lock);
					  try_to_free_buffers(page);
      get_bh(bh) <-- accesses freed bh

Fix the problem by grabbing bh reference before unlocking
journal->j_list_lock.

Fixes: dc6e8d66 ("jbd2: don't call get_bh() before calling __jbd2_journal_remove_checkpoint()")
Fixes: be1158cc ("jbd2: fold __process_buffer() into jbd2_log_do_checkpoint()")
Reported-by: syzbot+7f4a27091759e2fe7453@syzkaller.appspotmail.com
CC: stable@vger.kernel.org
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      25881163
  19. 30 7月, 2018 1 次提交
  21. 17 6月, 2018 1 次提交
  23. 13 6月, 2018 1 次提交
    • K
      treewide: kmalloc() -> kmalloc_array() · 6da2ec56
      由 Kees Cook 提交于 
      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: NKees Cook <keescook@chromium.org>
      6da2ec56
  25. 21 5月, 2018 2 次提交
  27. 18 4月, 2018 1 次提交
    • T
      ext4: set h_journal if there is a failure starting a reserved handle · b2569260
      由 Theodore Ts'o 提交于 
      If ext4 tries to start a reserved handle via
jbd2_journal_start_reserved(), and the journal has been aborted, this
can result in a NULL pointer dereference.  This is because the fields
h_journal and h_transaction in the handle structure share the same
memory, via a union, so jbd2_journal_start_reserved() will clear
h_journal before calling start_this_handle().  If this function fails
due to an aborted handle, h_journal will still be NULL, and the call
to jbd2_journal_free_reserved() will pass a NULL journal to
sub_reserve_credits().

This can be reproduced by running "kvm-xfstests -c dioread_nolock
generic/475".

Cc: stable@kernel.org # 3.11
Fixes: 8f7d89f3 ("jbd2: transaction reservation support")
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NAndreas Dilger <adilger@dilger.ca>
Reviewed-by: NJan Kara <jack@suse.cz>
      b2569260
  29. 20 2月, 2018 1 次提交
  31. 19 2月, 2018 2 次提交
    • T
      ext4: pass -ESHUTDOWN code to jbd2 layer · fb7c0244
      由 Theodore Ts'o 提交于 
      Previously the jbd2 layer assumed that a file system check would be
required after a journal abort.  In the case of the deliberate file
system shutdown, this should not be necessary.  Allow the jbd2 layer
to distinguish between these two cases by using the ESHUTDOWN errno.

Also add proper locking to __journal_abort_soft().
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
      fb7c0244
    • T
      jbd2: clarify bad journal block checksum message · ed65b00f
      由 Theodore Ts'o 提交于 
      There were two error messages emitted by jbd2, one for a bad checksum
for a jbd2 descriptor block, and one for a bad checksum for a jbd2
data block.  Change the data block checksum error so that the two can
be disambiguated.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
      ed65b00f
  33. 10 1月, 2018 1 次提交
    • T
      jbd2: fix sphinx kernel-doc build warnings · f69120ce
      由 Tobin C. Harding 提交于 
      Sphinx emits various (26) warnings when building make target 'htmldocs'.
Currently struct definitions contain duplicate documentation, some as
kernel-docs and some as standard c89 comments.  We can reduce
duplication while cleaning up the kernel docs.

Move all kernel-docs to right above each struct member.  Use the set of
all existing comments (kernel-doc and c89).  Add documentation for
missing struct members and function arguments.
Signed-off-by: NTobin C. Harding <me@tobin.cc>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
      f69120ce
  35. 18 12月, 2017 1 次提交
    • T
      ext4: fix up remaining files with SPDX cleanups · f5166768
      由 Theodore Ts'o 提交于 
      A number of ext4 source files were skipped due because their copyright
permission statements didn't match the expected text used by the
automated conversion utilities.  I've added SPDX tags for the rest.

While looking at some of these files, I've noticed that we have quite
a bit of variation on the licenses that were used --- in particular
some of the Red Hat licenses on the jbd2 files use a GPL2+ license,
and we have some files that have a LGPL-2.1 license (which was quite
surprising).

I've not attempted to do any license changes.  Even if it is perfectly
legal to relicense to GPL 2.0-only for consistency's sake, that should
be done with ext4 developer community discussion.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
      f5166768
  37. 03 11月, 2017 1 次提交
    • J
      ext4: Support for synchronous DAX faults · b8a6176c
      由 Jan Kara 提交于 
      We return IOMAP_F_DIRTY flag from ext4_iomap_begin() when asked to
prepare blocks for writing and the inode has some uncommitted metadata
changes. In the fault handler ext4_dax_fault() we then detect this case
(through VM_FAULT_NEEDDSYNC return value) and call helper
dax_finish_sync_fault() to flush metadata changes and insert page table
entry. Note that this will also dirty corresponding radix tree entry
which is what we want - fsync(2) will still provide data integrity
guarantees for applications not using userspace flushing. And
applications using userspace flushing can avoid calling fsync(2) and
thus avoid the performance overhead.
Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      b8a6176c
  39. 19 10月, 2017 1 次提交
  41. 06 7月, 2017 1 次提交
  43. 20 6月, 2017 1 次提交
  45. 22 5月, 2017 1 次提交
    • T
      jbd2: preserve original nofs flag during journal restart · b4709067
      由 Tahsin Erdogan 提交于 
      When a transaction starts, start_this_handle() saves current
PF_MEMALLOC_NOFS value so that it can be restored at journal stop time.
Journal restart is a special case that calls start_this_handle() without
stopping the transaction. start_this_handle() isn't aware that the
original value is already stored so it overwrites it with current value.

For instance, a call sequence like below leaves PF_MEMALLOC_NOFS flag set
at the end:

  jbd2_journal_start()
  jbd2__journal_restart()
  jbd2_journal_stop()

Make jbd2__journal_restart() restore the original value before calling
start_this_handle().

Fixes: 81378da6 ("jbd2: mark the transaction context with the scope GFP_NOFS context")
Signed-off-by: NTahsin Erdogan <tahsin@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
      b4709067
  47. 16 5月, 2017 2 次提交
  49. 04 5月, 2017 3 次提交
  51. 30 4月, 2017 2 次提交
    • J
      jbd2: fix dbench4 performance regression for 'nobarrier' mounts · 5052b069
      由 Jan Kara 提交于 
      Commit b685d3d6 "block: treat REQ_FUA and REQ_PREFLUSH as
synchronous" removed REQ_SYNC flag from WRITE_FUA implementation. Since
JBD2 strips REQ_FUA and REQ_FLUSH flags from submitted IO when the
filesystem is mounted with nobarrier mount option, journal superblock
writes ended up being async writes after this patch and that caused
heavy performance regression for dbench4 benchmark with high number of
processes. In my test setup with HP RAID array with non-volatile write
cache and 32 GB ram, dbench4 runs with 8 processes regressed by ~25%.

Fix the problem by making sure journal superblock writes are always
treated as synchronous since they generally block progress of the
journalling machinery and thus the whole filesystem.

Fixes: b685d3d6
CC: stable@vger.kernel.org
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
      5052b069
    • J
      jbd2: Fix lockdep splat with generic/270 test · c52c47e4
      由 Jan Kara 提交于 
      I've hit a lockdep splat with generic/270 test complaining that:

3216.fsstress.b/3533 is trying to acquire lock:
 (jbd2_handle){++++..}, at: [<ffffffff813152e0>] jbd2_log_wait_commit+0x0/0x150

but task is already holding lock:
 (jbd2_handle){++++..}, at: [<ffffffff8130bd3b>] start_this_handle+0x35b/0x850

The underlying problem is that jbd2_journal_force_commit_nested()
(called from ext4_should_retry_alloc()) may get called while a
transaction handle is started. In such case it takes care to not wait
for commit of the running transaction (which would deadlock) but only
for a commit of a transaction that is already committing (which is safe
as that doesn't wait for any filesystem locks).

In fact there are also other callers of jbd2_log_wait_commit() that take
care to pass tid of a transaction that is already committing and for
those cases, the lockdep instrumentation is too restrictive and leading
to false positive reports. Fix the problem by calling
jbd2_might_wait_for_commit() from jbd2_log_wait_commit() only if the
transaction isn't already committing.

Fixes: 1eaa566dSigned-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
      c52c47e4
  53. 19 4月, 2017 1 次提交
    • P
      mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU · 5f0d5a3a
      由 Paul E. McKenney 提交于 
      A group of Linux kernel hackers reported chasing a bug that resulted
from their assumption that SLAB_DESTROY_BY_RCU provided an existence
guarantee, that is, that no block from such a slab would be reallocated
during an RCU read-side critical section.  Of course, that is not the
case.  Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire
slab of blocks.

However, there is a phrase for this, namely "type safety".  This commit
therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order
to avoid future instances of this sort of confusion.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
[ paulmck: Add comments mentioning the old name, as requested by Eric
  Dumazet, in order to help people familiar with the old name find
  the new one. ]
Acked-by: NDavid Rientjes <rientjes@google.com>
      5f0d5a3a