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  1. 16 9月, 2019 1 次提交
    • C
      bcache: fix race in btree_flush_write() · b113f984
      由 Coly Li 提交于 
      [ Upstream commit 50a260e859964002dab162513a10f91ae9d3bcd3 ]

There is a race between mca_reap(), btree_node_free() and journal code
btree_flush_write(), which results very rare and strange deadlock or
panic and are very hard to reproduce.

Let me explain how the race happens. In btree_flush_write() one btree
node with oldest journal pin is selected, then it is flushed to cache
device, the select-and-flush is a two steps operation. Between these two
steps, there are something may happen inside the race window,
- The selected btree node was reaped by mca_reap() and allocated to
  other requesters for other btree node.
- The slected btree node was selected, flushed and released by mca
  shrink callback bch_mca_scan().
When btree_flush_write() tries to flush the selected btree node, firstly
b->write_lock is held by mutex_lock(). If the race happens and the
memory of selected btree node is allocated to other btree node, if that
btree node's write_lock is held already, a deadlock very probably
happens here. A worse case is the memory of the selected btree node is
released, then all references to this btree node (e.g. b->write_lock)
will trigger NULL pointer deference panic.

This race was introduced in commit cafe5635 ("bcache: A block layer
cache"), and enlarged by commit c4dc2497 ("bcache: fix high CPU
occupancy during journal"), which selected 128 btree nodes and flushed
them one-by-one in a quite long time period.

Such race is not easy to reproduce before. On a Lenovo SR650 server with
48 Xeon cores, and configure 1 NVMe SSD as cache device, a MD raid0
device assembled by 3 NVMe SSDs as backing device, this race can be
observed around every 10,000 times btree_flush_write() gets called. Both
deadlock and kernel panic all happened as aftermath of the race.

The idea of the fix is to add a btree flag BTREE_NODE_journal_flush. It
is set when selecting btree nodes, and cleared after btree nodes
flushed. Then when mca_reap() selects a btree node with this bit set,
this btree node will be skipped. Since mca_reap() only reaps btree node
without BTREE_NODE_journal_flush flag, such race is avoided.

Once corner case should be noticed, that is btree_node_free(). It might
be called in some error handling code path. For example the following
code piece from btree_split(),
        2149 err_free2:
        2150         bkey_put(b->c, &n2->key);
        2151         btree_node_free(n2);
        2152         rw_unlock(true, n2);
        2153 err_free1:
        2154         bkey_put(b->c, &n1->key);
        2155         btree_node_free(n1);
        2156         rw_unlock(true, n1);
At line 2151 and 2155, the btree node n2 and n1 are released without
mac_reap(), so BTREE_NODE_journal_flush also needs to be checked here.
If btree_node_free() is called directly in such error handling path,
and the selected btree node has BTREE_NODE_journal_flush bit set, just
delay for 1 us and retry again. In this case this btree node won't
be skipped, just retry until the BTREE_NODE_journal_flush bit cleared,
and free the btree node memory.

Fixes: cafe5635 ("bcache: A block layer cache")
Signed-off-by: NColy Li <colyli@suse.de>
Reported-and-tested-by: Nkbuild test robot <lkp@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      b113f984
  3. 26 7月, 2019 3 次提交
  5. 31 5月, 2019 2 次提交
    • T
      bcache: fix failure in journal relplay · cd83c788
      由 Tang Junhui 提交于 
      [ Upstream commit 631207314d88e9091be02fbdd1fdadb1ae2ed79a ]

journal replay failed with messages:
Sep 10 19:10:43 ceph kernel: bcache: error on
bb379a64-e44e-4812-b91d-a5599871a3b1: bcache: journal entries
2057493-2057567 missing! (replaying 2057493-20766016), disabling
caching

The reason is in journal_reclaim(), when discard is enabled, we send
discard command and reclaim those journal buckets whose seq is old
than the last_seq_now, but before we write a journal with last_seq_now,
the machine is restarted, so the journal with the last_seq_now is not
written to the journal bucket, and the last_seq_wrote in the newest
journal is old than last_seq_now which we expect to be, so when we doing
replay, journals from last_seq_wrote to last_seq_now are missing.

It's hard to write a journal immediately after journal_reclaim(),
and it harmless if those missed journal are caused by discarding
since those journals are already wrote to btree node. So, if miss
seqs are started from the beginning journal, we treat it as normal,
and only print a message to show the miss journal, and point out
it maybe caused by discarding.

Patch v2 add a judgement condition to ignore the missed journal
only when discard enabled as Coly suggested.

(Coly Li: rebase the patch with other changes in bch_journal_replay())
Signed-off-by: NTang Junhui <tang.junhui.linux@gmail.com>
Tested-by: NDennis Schridde <devurandom@gmx.net>
Signed-off-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      cd83c788
    • C
      bcache: return error immediately in bch_journal_replay() · 29b166da
      由 Coly Li 提交于 
      [ Upstream commit 68d10e6979a3b59e3cd2e90bfcafed79c4cf180a ]

When failure happens inside bch_journal_replay(), calling
cache_set_err_on() and handling the failure in async way is not a good
idea. Because after bch_journal_replay() returns, registering code will
continue to execute following steps, and unregistering code triggered
by cache_set_err_on() is running in same time. First it is unnecessary
to handle failure and unregister cache set in an async way, second there
might be potential race condition to run register and unregister code
for same cache set.

So in this patch, if failure happens in bch_journal_replay(), we don't
call cache_set_err_on(), and just print out the same error message to
kernel message buffer, then return -EIO immediately caller. Then caller
can detect such failure and handle it in synchrnozied way.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      29b166da
  7. 22 5月, 2019 1 次提交
    • C
      bcache: never set KEY_PTRS of journal key to 0 in journal_reclaim() · 88681649
      由 Coly Li 提交于 
      commit 1bee2addc0c8470c8aaa65ef0599eeae96dd88bc upstream.

In journal_reclaim() ja->cur_idx of each cache will be update to
reclaim available journal buckets. Variable 'int n' is used to count how
many cache is successfully reclaimed, then n is set to c->journal.key
by SET_KEY_PTRS(). Later in journal_write_unlocked(), a for_each_cache()
loop will write the jset data onto each cache.

The problem is, if all jouranl buckets on each cache is full, the
following code in journal_reclaim(),

529 for_each_cache(ca, c, iter) {
530       struct journal_device *ja = &ca->journal;
531       unsigned int next = (ja->cur_idx + 1) % ca->sb.njournal_buckets;
532
533       /* No space available on this device */
534       if (next == ja->discard_idx)
535               continue;
536
537       ja->cur_idx = next;
538       k->ptr[n++] = MAKE_PTR(0,
539                         bucket_to_sector(c, ca->sb.d[ja->cur_idx]),
540                         ca->sb.nr_this_dev);
541 }
542
543 bkey_init(k);
544 SET_KEY_PTRS(k, n);

If there is no available bucket to reclaim, the if() condition at line
534 will always true, and n remains 0. Then at line 544, SET_KEY_PTRS()
will set KEY_PTRS field of c->journal.key to 0.

Setting KEY_PTRS field of c->journal.key to 0 is wrong. Because in
journal_write_unlocked() the journal data is written in following loop,

649	for (i = 0; i < KEY_PTRS(k); i++) {
650-671		submit journal data to cache device
672	}

If KEY_PTRS field is set to 0 in jouranl_reclaim(), the journal data
won't be written to cache device here. If system crahed or rebooted
before bkeys of the lost journal entries written into btree nodes, data
corruption will be reported during bcache reload after rebooting the
system.

Indeed there is only one cache in a cache set, there is no need to set
KEY_PTRS field in journal_reclaim() at all. But in order to keep the
for_each_cache() logic consistent for now, this patch fixes the above
problem by not setting 0 KEY_PTRS of journal key, if there is no bucket
available to reclaim.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      88681649
  9. 27 9月, 2018 1 次提交
    • G
      bcache: add separate workqueue for journal_write to avoid deadlock · 0f843e65
      由 Guoju Fang 提交于 
      After write SSD completed, bcache schedules journal_write work to
system_wq, which is a public workqueue in system, without WQ_MEM_RECLAIM
flag. system_wq is also a bound wq, and there may be no idle kworker on
current processor. Creating a new kworker may unfortunately need to
reclaim memory first, by shrinking cache and slab used by vfs, which
depends on bcache device. That's a deadlock.

This patch create a new workqueue for journal_write with WQ_MEM_RECLAIM
flag. It's rescuer thread will work to avoid the deadlock.
Signed-off-by: NGuoju Fang <fangguoju@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      0f843e65
  11. 12 8月, 2018 4 次提交
  13. 27 7月, 2018 1 次提交
  15. 19 3月, 2018 3 次提交
    • B
      bcache: Reduce the number of sparse complaints about lock imbalances · 20d3a518
      由 Bart Van Assche 提交于 
      Add more annotations for sparse to inform it about which functions do
not have the same number of spin_lock() and spin_unlock() calls.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NMichael Lyle <mlyle@lyle.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      20d3a518
    • B
      bcache: Suppress more warnings about set-but-not-used variables · 42361469
      由 Bart Van Assche 提交于 
      This patch does not change any functionality.
Reviewed-by: NMichael Lyle <mlyle@lyle.org>
Reviewed-by: NColy Li <colyli@suse.de>
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      42361469
    • C
      bcache: add CACHE_SET_IO_DISABLE to struct cache_set flags · 771f393e
      由 Coly Li 提交于 
      When too many I/Os failed on cache device, bch_cache_set_error() is called
in the error handling code path to retire whole problematic cache set. If
new I/O requests continue to come and take refcount dc->count, the cache
set won't be retired immediately, this is a problem.

Further more, there are several kernel thread and self-armed kernel work
may still running after bch_cache_set_error() is called. It needs to wait
quite a while for them to stop, or they won't stop at all. They also
prevent the cache set from being retired.

The solution in this patch is, to add per cache set flag to disable I/O
request on this cache and all attached backing devices. Then new coming I/O
requests can be rejected in *_make_request() before taking refcount, kernel
threads and self-armed kernel worker can stop very fast when flags bit
CACHE_SET_IO_DISABLE is set.

Because bcache also do internal I/Os for writeback, garbage collection,
bucket allocation, journaling, this kind of I/O should be disabled after
bch_cache_set_error() is called. So closure_bio_submit() is modified to
check whether CACHE_SET_IO_DISABLE is set on cache_set->flags. If set,
closure_bio_submit() will set bio->bi_status to BLK_STS_IOERR and
return, generic_make_request() won't be called.

A sysfs interface is also added to set or clear CACHE_SET_IO_DISABLE bit
from cache_set->flags, to disable or enable cache set I/O for debugging. It
is helpful to trigger more corner case issues for failed cache device.

Changelog
v4, add wait_for_kthread_stop(), and call it before exits writeback and gc
    kernel threads.
v3, change CACHE_SET_IO_DISABLE from 4 to 3, since it is bit index.
    remove "bcache: " prefix when printing out kernel message.
v2, more changes by previous review,
- Use CACHE_SET_IO_DISABLE of cache_set->flags, suggested by Junhui.
- Check CACHE_SET_IO_DISABLE in bch_btree_gc() to stop a while-loop, this
  is reported and inspired from origal patch of Pavel Vazharov.
v1, initial version.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NMichael Lyle <mlyle@lyle.org>
Cc: Junhui Tang <tang.junhui@zte.com.cn>
Cc: Michael Lyle <mlyle@lyle.org>
Cc: Pavel Vazharov <freakpv@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      771f393e
  17. 08 2月, 2018 2 次提交
    • T
      bcache: fix high CPU occupancy during journal · c4dc2497
      由 Tang Junhui 提交于 
      After long time small writing I/O running, we found the occupancy of CPU
is very high and I/O performance has been reduced by about half:

[root@ceph151 internal]# top
top - 15:51:05 up 1 day,2:43,  4 users,  load average: 16.89, 15.15, 16.53
Tasks: 2063 total,   4 running, 2059 sleeping,   0 stopped,   0 zombie
%Cpu(s):4.3 us, 17.1 sy 0.0 ni, 66.1 id, 12.0 wa,  0.0 hi,  0.5 si,  0.0 st
KiB Mem : 65450044 total, 24586420 free, 38909008 used,  1954616 buff/cache
KiB Swap: 65667068 total, 65667068 free,        0 used. 25136812 avail Mem

  PID USER PR NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND
 2023 root 20  0       0      0      0 S 55.1  0.0   0:04.42 kworker/11:191
14126 root 20  0       0      0      0 S 42.9  0.0   0:08.72 kworker/10:3
 9292 root 20  0       0      0      0 S 30.4  0.0   1:10.99 kworker/6:1
 8553 ceph 20  0 4242492 1.805g  18804 S 30.0  2.9 410:07.04 ceph-osd
12287 root 20  0       0      0      0 S 26.7  0.0   0:28.13 kworker/7:85
31019 root 20  0       0      0      0 S 26.1  0.0   1:30.79 kworker/22:1
 1787 root 20  0       0      0      0 R 25.7  0.0   5:18.45 kworker/8:7
32169 root 20  0       0      0      0 S 14.5  0.0   1:01.92 kworker/23:1
21476 root 20  0       0      0      0 S 13.9  0.0   0:05.09 kworker/1:54
 2204 root 20  0       0      0      0 S 12.5  0.0   1:25.17 kworker/9:10
16994 root 20  0       0      0      0 S 12.2  0.0   0:06.27 kworker/5:106
15714 root 20  0       0      0      0 R 10.9  0.0   0:01.85 kworker/19:2
 9661 ceph 20  0 4246876 1.731g  18800 S 10.6  2.8 403:00.80 ceph-osd
11460 ceph 20  0 4164692 2.206g  18876 S 10.6  3.5 360:27.19 ceph-osd
 9960 root 20  0       0      0      0 S 10.2  0.0   0:02.75 kworker/2:139
11699 ceph 20  0 4169244 1.920g  18920 S 10.2  3.1 355:23.67 ceph-osd
 6843 ceph 20  0 4197632 1.810g  18900 S  9.6  2.9 380:08.30 ceph-osd

The kernel work consumed a lot of CPU, and I found they are running journal
work, The journal is reclaiming source and flush btree node with surprising
frequency.

Through further analysis, we found that in btree_flush_write(), we try to
get a btree node with the smallest fifo idex to flush by traverse all the
btree nodein c->bucket_hash, after we getting it, since no locker protects
it, this btree node may have been written to cache device by other works,
and if this occurred, we retry to traverse in c->bucket_hash and get
another btree node. When the problem occurrd, the retry times is very high,
and we consume a lot of CPU in looking for a appropriate btree node.

In this patch, we try to record 128 btree nodes with the smallest fifo idex
in heap, and pop one by one when we need to flush btree node. It greatly
reduces the time for the loop to find the appropriate BTREE node, and also
reduce the occupancy of CPU.

[note by mpl: this triggers a checkpatch error because of adjacent,
pre-existing style violations]
Signed-off-by: NTang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: NMichael Lyle <mlyle@lyle.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      c4dc2497
    • T
      bcache: add journal statistic · a728eacb
      由 Tang Junhui 提交于 
      Sometimes, Journal takes up a lot of CPU, we need statistics
to know what's the journal is doing. So this patch provide
some journal statistics:
1) reclaim: how many times the journal try to reclaim resource,
   usually the journal bucket or/and the pin are exhausted.
2) flush_write: how many times the journal try to flush btree node
   to cache device, usually the journal bucket are exhausted.
3) retry_flush_write: how many times the journal retry to flush
   the next btree node, usually the previous tree node have been
   flushed by other thread.
we show these statistic by sysfs interface. Through these statistics
We can totally see the status of journal module when the CPU is too
high.
Signed-off-by: NTang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: NMichael Lyle <mlyle@lyle.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      a728eacb
  19. 25 11月, 2017 2 次提交
    • H
      bcache: Fix building error on MIPS · cf33c1ee
      由 Huacai Chen 提交于 
      This patch try to fix the building error on MIPS. The reason is MIPS
has already defined the PTR macro, which conflicts with the PTR macro
in include/uapi/linux/bcache.h.

[fixed by mlyle: corrected a line-length issue]

Cc: stable@vger.kernel.org
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Reviewed-by: NMichael Lyle <mlyle@lyle.org>
Signed-off-by: NMichael Lyle <mlyle@lyle.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      cf33c1ee
    • T
      bcache: add a comment in journal bucket reading · bb22cafd
      由 Tang Junhui 提交于 
      Journal bucket is a circular buffer, the bucket
can be like YYYNNNYY, which means the first valid journal in
the 7th bucket, and the latest valid journal in third bucket, in
this case, if we do not try we the zero index first, We
may get a valid journal in the 7th bucket, then we call
find_next_bit(bitmap,ca->sb.njournal_buckets, l + 1) to get the
first invalid bucket after the 7th bucket, because all these
buckets is valid, so no bit 1 in bitmap, thus find_next_bit()
function would return with ca->sb.njournal_buckets (8). So, after
that, bcache only read journal in 7th and 8the bucket,
the first to the third buckets are lost.

So, it is important to let developer know that, we need to try
the zero index at first in the hash-search, and avoid any breaks
in future's code modification.

[ML: Fixed whitespace & formatting & file permissions]
Signed-off-by: NTang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: NMichael Lyle <mlyle@lyle.org>
Reviewed-by: NMichael Lyle <mlyle@lyle.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      bb22cafd
  21. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      由 Greg Kroah-Hartman 提交于 
      Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  23. 24 8月, 2017 1 次提交
    • C
      block: replace bi_bdev with a gendisk pointer and partitions index · 74d46992
      由 Christoph Hellwig 提交于 
      This way we don't need a block_device structure to submit I/O.  The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open.  Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device.  But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      74d46992
  25. 09 6月, 2017 1 次提交
  27. 22 11月, 2016 1 次提交
  29. 08 6月, 2016 3 次提交
  31. 14 8月, 2015 1 次提交
  33. 29 7月, 2015 1 次提交
    • C
      block: add a bi_error field to struct bio · 4246a0b6
      由 Christoph Hellwig 提交于 
      Currently we have two different ways to signal an I/O error on a BIO:

 (1) by clearing the BIO_UPTODATE flag
 (2) by returning a Linux errno value to the bi_end_io callback

The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario.  Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.

So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>
      4246a0b6
  35. 11 7月, 2015 1 次提交
  37. 01 7月, 2015 1 次提交
  39. 05 8月, 2014 3 次提交
  41. 19 3月, 2014 4 次提交
    • K
      bcache: btree locking rework · 2a285686
      由 Kent Overstreet 提交于 
      Add a new lock, b->write_lock, which is required to actually modify - or write -
a btree node; this lock is only held for short durations.

This means we can write out a btree node without taking b->lock, which _is_ held
for long durations - solving a deadlock when btree_flush_write() (from the
journalling code) is called with a btree node locked.

Right now just occurs in bch_btree_set_root(), but with an upcoming journalling
rework is going to happen a lot more.

This also turns b->lock is now more of a read/intent lock instead of a
read/write lock - but not completely, since it still blocks readers. May turn it
into a real intent lock at some point in the future.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>
      2a285686
    • K
      bcache: Add bch_keylist_init_single() · c13f3af9
      由 Kent Overstreet 提交于 
      This will potentially save us an allocation when we've got inode/dirent bkeys
that don't fit in the keylist's inline keys.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>
      c13f3af9
    • K
      bcache: Fix another bug recovering from unclean shutdown · 487dded8
      由 Kent Overstreet 提交于 
      The on disk bucket gens are allowed to be out of date, when we reuse buckets
that didn't have any live data in them. To deal with this, the initial gc has to
update the bucket gen when we find a pointer gen newer than the bucket's gen.

Unfortunately we weren't doing this for pointers in the journal that we're about
to replay.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>
      487dded8
    • K
      bcache: Fix a journalling reclaim after recovery bug · 27201cfd
      由 Kent Overstreet 提交于 
      On recovery we weren't correctly keeping track of what journal buckets had open
journal entries, thus it was possible for them to be overwritten until we'd
written all new journal entries.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>
      27201cfd
  43. 18 3月, 2014 1 次提交
  45. 26 2月, 2014 1 次提交