Commit Graph

471 Commits

Author SHA1 Message Date
Brian Behlendorf
ed19bccfb6
Linux 4.14 compat: vfs_read & vfs_write
The kernel_read & kernel_write functions have always wrapped the
vfs_read & vfs_write functions respectively.  However, they could
not be used by vn_rdwr() since the offset wasn't passed as a
pointer.  This prevented us from being able to properly update
the file offset.

Linux 4.14 unexported vfs_read & vfs_write but also changed the
signature of kernel_read & kernel_write to provide the needed
functionality.  Use these updated functions when available.

Reviewed-by: Pritam Baral <pritam@pritambaral.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #656 
Closes #667
2017-11-15 17:19:23 -08:00
James Cowgill
35a44fcb8d Remove all spin_is_locked calls
On systems with CONFIG_SMP turned off, spin_is_locked always returns
false causing these assertions to fail. Remove them as suggested in
zfsonlinux/zfs#6558.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: James Cowgill <james.cowgill@mips.com>
Closes #665
2017-10-30 11:16:56 -07:00
Brian Behlendorf
8be3688999
Remove vn_rename and vn_remove
Both vn_rename and vn_remove have been historically problematic
to implement reliably.  Rather than fixing them yet again they
are being removed.

Reviewed-by: Arkadiusz Bubala <arkadiusz.bubala@open-e.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #648 
Closes #661
2017-10-27 15:49:14 -07:00
Olaf Faaland
4b393c50ae Make file headers conform to ZFS style standard
No semantic changes.

Change
 /************\
and
 \************/

to

 /*
and
  */

Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
2017-10-09 14:27:27 -07:00
Richard Elling
e8474f9ad3 Pool io stat shows wlentime instead of rlentime
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Elling <Richard.Elling@RichardElling.com>
Closes #652 
Closes #651
2017-09-25 10:02:24 -07:00
gaurkuma
9df9692637 Allow longer SPA names in stats
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: gaurkuma <gauravk.18@gmail.com>
Closes #641
2017-08-11 08:53:35 -07:00
Fabian-Gruenbichler
bbefaeba29 make module/spl/spl-kmem.c non-executable (again)
This was probably accidentally committed in

aeb9baa618
Fix: handle NULL case in spl_kmem_free_track()

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Closes #644
2017-08-10 15:23:43 -07:00
Boris Protopopov
9243b0fb47 Add assert under lock to detect cases of dispach of a preallocated
taskq work item to more than one queue concurrently. Also, please
see discussion in zfsonlinux/zfs#3840.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Boris Protopopov <boris.protopopov@actifio.com>
Closes #609
2017-08-08 08:31:52 -07:00
Chunwei Chen
cce83ba0ec Fix use-after-free in taskq_seq_show_impl
taskq_seq_show_impl walks the tq_active_list to show the tqent_func and
tqent_arg. However for taskq_dispatch_ent, it's very likely that the
task entry will be freed during the function call, and causes a
use-after-free bug.

To fix this, we duplicate the task entry to an on-stack struct, and
assign it instead to tqt_task. This way, the tq_lock alone will
guarantee its safety.

Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #638 
Closes #640
2017-08-04 09:57:58 -07:00
Chunwei Chen
6ecfd2b553 Add __divmoddi4 and __udivmoddi4 for 32-bit arch
gcc-7 seems to use __udivmoddi4 for 64-bit division on 32-bit arch. This
patch implement them so we don't get undefined reference error.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes zfsonlinux/zfs#6417 
Closes #636
2017-08-03 10:41:42 -07:00
Oleg Drokin
410f7ab594 Module parameter to enable spl_panic() to panic the kernel
In unattended operations it's often more useful to have node
panic and reboot when it encounters problems as opposed to
sit there indefinitely waiting for somebody to discover it.

This implements an spl_panic_crash module parameter, set it
to nonzero to cause spl_panic() to call panic().

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Closes #634
2017-07-25 23:03:12 -07:00
LOLi
cd47801828 Avoid WARN() from procfs on kstat collision
When we load a ZFS pool having spa_name equals to some existing kstat
we would have to create a duplicate entry, which procfs doesn't like.

For instance a ZFS pool named "zil" would have its kstat "txgs"
(module "zfs/zil") intalled under "/proc/spl/kstat/zfs/zil":
unfortunately we already have a kstat named "zil" (module "zfs")
installed in the same procfs location.

Avoid this issue by skipping the duplicate entry creation in procfs.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes #628
2017-07-24 10:52:53 -07:00
Brian Behlendorf
944117514d Linux 4.13 compat: wait queues
Commit torvalds/linux@ac6424b9
- Renamed struct wait_queue -> struct wait_queue_entry.

Commit torvalds/linux@2055da97
- Renamed wait_queue_head::task_list -> wait_queue_head::head
- Renamed wait_queue_entry::task_list -> wait_queue_entry::entry

Reviewed-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #629
2017-07-23 19:32:14 -07:00
Brian Behlendorf
c93d9dff36 Don't cache the system hostid
Historically the SPL cached the system hostid the first time it
was accessed.  This was done to speed up subsequent accesses.
But in practice the system host id is rarely accessed and its
inconvenient that it doesn't promptly detect /etc/hostid
configuration changes.  Therefore, zone_get_hostid() has been
updated to always refresh the system hostid reported.

Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #626
2017-07-13 13:22:28 -04:00
Chunwei Chen
3bda331ba8 Improve gitignore
Exclude Makefile.in in module/ and fix the gitignore in cmd/
Also, ignore *.patch and *.orig files

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
2017-05-25 10:12:50 -07:00
Brian Behlendorf
2ded1c7eff Fix cv_timedwait timeout
Perform the already past expiration time check before updating
cvp->cv_mutex with the provided mutex.  This check only depends
on local state.  Doing it first ensures that cvp->cv_mutex will not
be updated in the timeout case or if it's ever called with an
expire_time <= now.

Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #616
2017-05-25 10:01:44 -07:00
Chunwei Chen
8f87971e1f Linux 4.12 compat: PF_FSTRANS was removed
Change SPL_FSTRANS to optionally contains PF_FSTRANS. Also, add
__spl_pf_fstrans_check for the checks specifically for PF_FSTRANS.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #614
2017-05-09 10:36:54 -07:00
Olaf Faaland
bf8abea4da Linux 4.11 compat: remove stub for __put_task_struct
Before kernel 2.6.29 credentials were embedded in task_structs, and zfs had
cases where one thread would need to refer to the credential of another thread,
forcing it to take a hold on the foreign thread's task_struct to ensure it was
not freed.

Since 2.6.29, the credential has been moved out of the task_struct into a
cred_t.

In addition, the mainline kernel originally did not export __put_task_struct()
but the RHEL5 kernel did, according to zfsonlinux/spl@e811949a57.  As of
2.6.39 the mainline kernel exports it.

There is no longer zfs code that takes or releases holds on a task_struct, and
so there is no longer any reference to __put_task_struct().

This affects the linux 4.11 kernel because the prototype for
__put_task_struct() is in a new include file (linux/sched/task.h) and so the
config check failed to detect the exported symbol.

Removing the unnecessary stub and corresponding config check.  This works on
kernels since the oldest one currently supported, 2.6.32 as shipped with
Centos/RHEL.

Reviewed-by: Chunwei Chen <david.chen@osnexus.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #608
2017-03-20 17:43:45 -07:00
Olaf Faaland
94b1ab2ae0 Linux 4.11 compat: vfs_getattr() takes 4 args
There are changes to vfs_getattr() in torvalds/linux@a528d35.  The new
interface is:

int vfs_getattr(const struct path *path, struct kstat *stat,
               u32 request_mask, unsigned int query_flags)

The request_mask argument indicates which field(s) the caller intends to
use.  Fields the caller does not specify via request_mask may be set in
the returned struct anyway, but their values may be approximate.

The query_flags argument indicates whether the filesystem must update
the attributes from the backing store.

This patch uses the query_flags which result in vfs_getattr behaving the same
as it did with the 2-argument version which the kernel provided before
Linux 4.11.

Members blksize and blocks are now always the same size regardless of
arch.  They match the size of the equivalent members in vnode_t.

The configure checks are modified to ensure that the appropriate
vfs_getattr() interface is used.

A more complete fix, removing the ZFS dependency on vfs_getattr()
entirely, is deferred as it is a much larger project.

Reviewed-by: Chunwei Chen <david.chen@osnexus.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #608
2017-03-20 17:43:39 -07:00
Olaf Faaland
8d5feecacf Linux 4.11 compat: set_task_state() removed
Replace uses of set_task_state(current, STATE) with
set_current_state(STATE).

In Linux 4.11, torvalds/linux@642fa44, set_task_state() is removed.

All spl uses are of the form set_task_state(current, STATE).
set_current_state(STATE) is equivalent and has been available since
Linux 2.2.26.

Furthermore, set_current_state(STATE) is already used in about 15
locations within spl.  This change should have no impact other than
removing an unnecessary dependency.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #603
2017-02-23 09:52:08 -08:00
Chunwei Chen
97048200f8 Use kernel slab for vn_cache and vn_file_cache
Resolve a false positive in the kmemleak checker by shifting to the
kernel slab.  It shows up because vn_file_cache is using KMC_KMEM
which is directly allocated using __get_free_pages, which is not
automatically tracked by kmemleak.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #599
2017-01-31 13:44:01 -08:00
clefru
2d4d81c485 Reimplement rt_mutex_owner to fix build with DEBUG & PREEMPT_RT_FULL
rt_mutex_owner is internal to kernel/locking/rtmutex_common.h and
inaccessible for SPL via the public kernel headers. The way of
accessing the owner has been stable since at least 3.13 ([1], [2]),
which is masking the lowest bit in the owner pointer in rt_mutex. We
do the same.

[1] http://lxr.free-electrons.com/source/kernel/locking/rtmutex_common.h?v=3.13#L99
[2] http://lxr.free-electrons.com/source/kernel/locking/rtmutex_common.h?v=4.9#L78

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Clemens Fruhwirth <clemens@endorphin.org>
Closes #593
2017-01-19 14:41:38 -08:00
George Melikov
5cb44271b4 Remove identical if statements in module/spl/spl-vnode.c
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes #594
2017-01-19 14:32:45 -08:00
Kevin Tanguy
0194e4a03c Add support for recent kmem_cache_create_usercopy
SLAB_USERCOPY flag was used to indicate PAX
not to kill copies from kernel to userland.

With recent grsecurity patchset and
CONFIG_GRKERNSEC_HIDESYM that enables
CONFIG_PAX_USERCOPY zfs would panic.

Handle newer API while keeping old one functional.

Tested-by: RageLtMan <rageltman@sempervictus>
Reviewed-by: spendergrsec <spender@grsecurity.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Kevin Tanguy <kevin.tanguy@ovh.net>
Closes #595
2017-01-17 12:05:14 -08:00
RageLtMan
120faefed9 Update struct member intializers to C89
When building SPL within the kernel tree, C99 initializers cause
build failures and need to be converted to C89 as kernel CFLAGS
specify -std=gnu89.

This fix was provided by @behlendorf in #595 discussion notes and
manually implemented in the current master revision.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: RageLtMan <rageltman@sempervictus>
Closes #597
2017-01-13 14:12:42 -08:00
Clemens Fruhwirth
8e99d66b05 Add support for rw semaphore under PREEMPT_RT_FULL
The main complication from the RT patch set is that the RW semaphore
locks change such that read locks on an rwsem can be taken only by
a single thread.  All other threads are locked out. This single
thread can take a read lock multiple times though. The underlying
implementation changes to a mutex with an additional read_depth
count.

The implementation can be best understood by inspecting the RT
patch.  rwsem_rt.h and rt.c give the best insight into how RT
rwsem works. My implementation for rwsem_tryupgrade is basically
an inversion of rt_downgrade_write found in rt.c. Please see the
comments in the code.

Unfortunately, I have to drop SPLAT rwlock test4 completely as this
test tries to take multiple locks from different threads, which RT
rwsems do not support.  Otherwise SPLAT, zconfig.sh, zpios-sanity.sh
and zfs-tests.sh pass on my Debian-testing VM with the kernel
linux-image-4.8.0-1-rt-amd64.

Tested-by: kernelOfTruth <kerneloftruth@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Clemens Fruhwirth <clemens@endorphin.org>
Closes zfsonlinux/zfs#5491
Closes #589
Closes #308
2016-12-19 12:45:24 -08:00
Chunwei Chen
9c9ad845ef Refactor some splat macro to function
Refactor the code by making splat_test_{init,fini}, splat_subsystem_{init,fini}
into functions. They don't have reason to be macro and it would be too bloated
to inline every call.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
2016-12-15 11:30:11 -08:00
Chunwei Chen
71a3c9c45d Fix splat memleak
SPLAT_TEST_FINI didn't call kfree causing memleak.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
2016-12-15 11:30:11 -08:00
Chunwei Chen
f200b83673 Add system_delay_taskq for long delay
Add a dedicated system_delay_taskq for long delay like spa_deadman and
zpl_posix_acl_free. This will allow us to use system_taskq in the manner of
dispatch multiple tasks and call taskq_wait_outstanding.

Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #588
2016-12-08 14:00:20 -07:00
Chunwei Chen
493492559e Limit number of tasks shown in taskq proc
To prevent holding tq_lock for too long.

Before zfsonlinux/zfs@8e71ab9, hogging delay tasks and cat /proc/spl/taskq
would easily cause a lockup. While that bug has been fixed. It's probably
still a good idea to do this just in case task lists grow too large.

Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #586
2016-12-01 11:06:27 -07:00
Ubuntu
cbba714667 Add TASKQID_INVALID and TASKQID_INITIAL macros
Add the TASKQID_INVALID and TASKQID_INITIAL macros and update the
taskq implementation and test cases to use them.  This is solely
for the purposes of readability and introduces no functional change.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-11-02 10:34:19 -07:00
Ubuntu
1b457bcbe5 Fix vmem_size()
Add a minimal implementation of vmem_size() which accounts for the
virtual memory usage of the SPL's kmem cache.  This functionality
is only useful on 32-bit systems with a small virtual address space.

The following assumptions are made:

  1) The major SPL consumer of virtual memory is the kmem cache.
  2) Memory allocated with vmem_alloc() is short lived and can be ignored.
  3) Allow a 4MB floor as a generous pad given normal consumption.
  4) The spl_kmem_cache_sem only contends with cache create/destroy.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-11-02 10:34:19 -07:00
Chunwei Chen
ae7eda1dde Linux 4.9 compat: group_info changes
In Linux 4.9, torvalds/linux@81243ea, group_info changed from 2d array via
->blocks to 1d array via ->gid. We change the spl cred functions accordingly.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #581
2016-10-20 09:33:28 -07:00
Chunwei Chen
87063d7dc3 Fix splat-cred.c cred usage
No need to crhold current_cred(), fix possible leak in splat_cred_test2

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #556
2016-10-20 09:33:22 -07:00
Chunwei Chen
9ba3c01923 Fix crgetgroups out-of-bound and misc cred fix
init_groups has 0 nblocks, therefore calling the current crgetgroups with
init_groups would result in out-of-bound access. We fix this by returning NULL
when nblocks is 0.

Cap crgetngroups to NGROUPS_PER_BLOCK, since crgetgroups will only return
blocks[0].

Also, remove all get_group_info. The cred already holds reference on the
group_info, and cred is not mutable. So there's no reason to hold extra
reference, if we hold cred.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #556
2016-10-20 09:33:01 -07:00
tuxoko
0d26756665 Fix out-of-bound in per_cpu in spl_random_init
When iterating per_cpu values, we need to use for_each_possible_cpu. While
NR_CPUS indicates the number of CPU supported by the kernel, it might not
initialize all of them if the kernel decides it's not possible to use them.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #578
2016-10-07 20:59:46 -07:00
Brian Behlendorf
341dfdb3fd Fix p0 initializer
Due to changes in the task_struct the following warning is occurs
when initializing the global p0.  Since this structure only exists
for it's address to be taken initialize it in a manor which isn't
sensitive to internal changes to the structure.

  module/spl/spl-generic.c:58:1: error: missing braces around
  initializer [-Werror=missing-braces]

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #576
2016-10-04 17:26:36 -07:00
Brian Behlendorf
6c2a66bfa8 Fix aarch64 type warning
Explicitly cast type in splat-rwlock.c test case to silence
the following warning.

  warning: format ‘%ld’ expects argument of type ‘long int’,
  but argument N has type ‘int’

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #574
2016-10-01 18:33:01 -07:00
Brian Behlendorf
cb81c0c588 Increase spl_kmem_alloc_warn limit
In order to support ABD with large blocks the spl_kmem_alloc_warn
limit needs to be increased to 64K.

A 16M block requires that pointers be stored for 4096 4K-pages
on an x86_64 system.  Each of these pointers is 8 bytes requiring
an allocation of 8*4096=32,768 bytes.  The addition of a small
header to this structure pushes the allocation over the default
32K warning threshold.

In addition, fix a small bug where MAX was used instead of MIN
when setting the default.  This ensures a reasonable limit is
still set on systems with page sizes larger then 4K.

Reviewed-by: David Quigley <david.quigley@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #571
2016-09-16 17:10:36 -07:00
GeLiXin
aeb9baa618 Fix: handle NULL case in spl_kmem_free_track()
When DEBUG_KMEM_TRACKING is enabled in SPL, we keep tracking all
the buffers alloced by kmem_alloc() and kmem_zalloc().  If a NULL
pointer which indicates no track info in SPL is passed to
spl_kmem_free_track, we just ignore it.

Signed-off-by: GeLiXin <ge.lixin@zte.com.cn>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue zfsonlinux/zfs#4967
Closes #567
2016-08-19 09:14:24 -07:00
Brian Behlendorf
b7c7008ba2 Linux 4.8 compat: rw_semaphore atomic_long_t count
For non-rwsem-spinlocks the "count" member was changed from a
"long" to "atomic_long_t" type.  A configure check has been
added to detect this change along with new versions of the
_rwsem_tryupgrade() function and RWSEM_COUNT() macro.  See
https://github.com/torvalds/linux/commit/8ee62b18 for complete
details.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #563
2016-07-29 14:17:53 -07:00
Jinshan Xiong
16fc1ec3ba Improve spl slab cache alloc
The policy is to try to allocate with KM_NOSLEEP, which will lead to
memory allocation with GFP_ATOMIC, and if it fails, it will launch
an taskq to expand slab space.

This way it should be able to get better NUMA memory locality and
reduce the overhead of context switch.

Signed-off-by: Jinshan Xiong <jinshan.xiong@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #551
2016-06-01 10:26:42 -07:00
Chunwei Chen
ea5f1a200b Fix use-after-free in splat_taskq_test7
This splat_vprint is using tq_arg->name after tq_arg is freed.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #557
2016-05-31 11:58:42 -07:00
Chunwei Chen
f58040c0fc Implement a proper rw_tryupgrade
Current rw_tryupgrade does rw_exit and then rw_tryenter(RW_RWITER), and then
does rw_enter(RW_READER) if it fails. This violate the assumption that
rw_tryupgrade should be atomic and could cause extra contention or even lock
inversion.

This patch we implement a proper rw_tryupgrade. For rwsem-spinlock, we take
the spinlock to check rwsem->count and rwsem->wait_list. For normal rwsem, we
use cmpxchg on rwsem->count to change the value from single reader to single
writer.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes zfsonlinux/zfs#4692
Closes #554
2016-05-31 11:44:15 -07:00
Chunwei Chen
b3a22a0a00 Fix taskq_wait_outstanding re-evaluate tq_next_id
wait_event is a macro, so the current implementation will cause re-
evaluation of tq_next_id every time it wakes up. This would cause
taskq_wait_outstanding(tq, 0) to be equivalent to taskq_wait(tq)

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Issue #553
2016-05-24 13:02:10 -07:00
Chunwei Chen
5ce028b0d4 Fix race between taskq_destroy and dynamic spawning thread
While taskq_destroy would wait for dynamic_taskq to finish its tasks, but it
does not implies the thread being spawned is up and running. This will cause
taskq to be freed before the thread can exit.

We fix this by using tq_nspawn to indicate how many threads are being spawned
before they are inserted to the thread list. And have taskq_destroy to wait
for it to drop to zero.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Issue #553
Closes #550
2016-05-24 13:00:17 -07:00
Chunwei Chen
872e0cc9c7 Restore CALLOUT_FLAG_ABSOLUTE in cv_timedwait_hires
In 39cd90e, I mistakenly disabled the ability of using absolute expire time in
cv_timedwait_hires. I don't quite sure why I did that, so let's restore it.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Issue #553
2016-05-24 12:58:49 -07:00
Chunwei Chen
fdbc1ba99d Linux 4.7 compat: inode_lock() and friends
Linux 4.7 changes i_mutex to i_rwsem, and we should used inode_lock and
inode_lock_shared to do exclusive and shared lock respectively.

We use spl_inode_lock{,_shared}() to hide the difference. Note that on older
kernel you'll always take an exclusive lock.

We also add all other inode_lock friends. And nested users now should
explicitly call spl_inode_lock_nested with correct subclass.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue zfsonlinux/zfs#4665
Closes #549
2016-05-20 11:00:14 -07:00
Chunwei Chen
39cd90ef08 Add cv_timedwait_sig_hires to allow interruptible sleep
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #548
2016-05-12 14:54:15 -07:00
Tim Chase
ea2633ad26 Clear PF_FSTRANS over spl_filp_fallocate()
The problem described in 2a5d574 also applies to XFS's file or inode
fallocate method.  Both paths may trigger writeback and expose this
issue, see the full stack below.

When layered on XFS a warning will be emitted under CentOS7 when entering
either the file or inode fallocate method with PF_FSTRANS already set.
To avoid triggering this error PF_FSTRANS is cleared and then reset
in vn_space().

WARNING: at fs/xfs/xfs_aops.c:982 xfs_vm_writepage+0x58b/0x5d0

Call Trace:
 [<ffffffff810a1ed5>] warn_slowpath_common+0x95/0xe0
 [<ffffffff810a1f3a>] warn_slowpath_null+0x1a/0x20
 [<ffffffffa0231fdb>] xfs_vm_writepage+0x58b/0x5d0 [xfs]
 [<ffffffff81173ed7>] __writepage+0x17/0x40
 [<ffffffff81176f81>] write_cache_pages+0x251/0x530
 [<ffffffff811772b1>] generic_writepages+0x51/0x80
 [<ffffffffa0230cb0>] xfs_vm_writepages+0x60/0x80 [xfs]
 [<ffffffff81177300>] do_writepages+0x20/0x30
 [<ffffffff8116a5f5>] __filemap_fdatawrite_range+0xb5/0x100
 [<ffffffff8116a6cb>] filemap_write_and_wait_range+0x8b/0xd0
 [<ffffffffa0235bb4>] xfs_free_file_space+0xf4/0x520 [xfs]
 [<ffffffffa023cbce>] xfs_file_fallocate+0x19e/0x2c0 [xfs]
 [<ffffffffa036c6fc>] vn_space+0x3c/0x40 [spl]
 [<ffffffffa0434817>] vdev_file_io_start+0x207/0x260 [zfs]
 [<ffffffffa047170d>] zio_vdev_io_start+0xad/0x2d0 [zfs]
 [<ffffffffa0474942>] zio_execute+0x82/0xe0 [zfs]
 [<ffffffffa036ba7d>] taskq_thread+0x28d/0x5a0 [spl]
 [<ffffffff810c1777>] kthread+0xd7/0xf0
 [<ffffffff8167de2f>] ret_from_fork+0x3f/0x70

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Closes zfsonlinux/zfs#4529
2016-04-26 11:22:43 -07:00