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When a waiting plock request (F_SETLKW) is sent to userspace
for processing (dlm_controld), the result is returned at a
later time. That result could be incorrectly matched to a
different waiting request in cases where the owner field is
the same (e.g. different threads in a process.) This is fixed
by comparing all the properties in the request and reply.
The results for non-waiting plock requests are now matched
based on list order because the results are returned in the
same order they were sent.
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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While a non-waiting posix lock request (F_SETLK) is waiting for
user space processing (in dlm_controld), wait for that processing
to complete with an unkillable wait_event(). This makes F_SETLK
behave the same way for F_RDLCK, F_WRLCK and F_UNLCK. F_SETLKW
continues to use wait_event_killable().
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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If a posix lock request is waiting for a result from user space
(dlm_controld), do not let it be interrupted unless the process
is killed. This reverts commit a6b1533e9a57 ("dlm: make posix locks
interruptible"). The problem with the interruptible change is
that all locks were cleared on any signal interrupt. If a signal
was received that did not terminate the process, the process
could continue running after all its dlm posix locks had been
cleared. A future patch will add cancelation to allow proper
interruption.
Cc: stable@vger.kernel.org
Fixes: a6b1533e9a57 ("dlm: make posix locks interruptible")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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Immediately clean up a posix lock request if it is interrupted
while waiting for a result from user space (dlm_controld.) This
largely reverts the recent commit b92a4e3f86b1 ("fs: dlm: change
posix lock sigint handling"). That previous commit attempted
to defer lock cleanup to the point in time when a result from
user space arrived. The deferred approach was not reliable
because some dlm plock ops may not receive replies.
Cc: stable@vger.kernel.org
Fixes: b92a4e3f86b1 ("fs: dlm: change posix lock sigint handling")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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The GETLK pid values have all been negated since commit 9d5b86ac13c5
("fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks").
Revert this for local pids, and leave in place negative pids for remote
owners.
Cc: stable@vger.kernel.org
Fixes: 9d5b86ac13c5 ("fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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The file locking definitions have lived in fs.h since the dawn of time,
but they are only used by a small subset of the source files that
include it.
Move the file locking definitions to a new header file, and add the
appropriate #include directives to the source files that need them. By
doing this we trim down fs.h a bit and limit the amount of rebuilding
that has to be done when we make changes to the file locking APIs.
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Steve French <stfrench@microsoft.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
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This patch changes the handling of a plock operation that was interrupted
while waiting for a user space reply from dlm_controld. (This is not
the lock blocking state, i.e. locks_lock_file_wait().)
Currently, when an op is interrupted while waiting on user space, the
op is removed. When the user space result later arrives, a kernel
message is loggged: "dev_write no op...". This can be seen from a test
such as "stress-ng --fcntl 100" and interrupting it with ctrl-c.
Now, leave the op in place when interrupted and remove it when the
result arrives (the result will be ignored.) With this change, the
logged message is not expected to appear, and would indicate a bug.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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This patch refactors do_unlock_close() by using only struct dlm_plock_info
as a parameter.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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This patch reverses the commit bcfad4265ced ("dlm: improve plock logging
if interrupted") by moving it to debug level and notifying the user an op
was removed.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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This patch adds the pid information which requested the lock operation
to the debug log output.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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This patch will use the list helper list_first_entry() instead of using
list_entry() to get the first element of a list.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.
To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].
This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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Instead of init global module at module loading time we can move the
initialization of those global variables at memory initialization of the
module loader.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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There is no need to call INIT_LIST_HEAD() when it's set directly
afterwards by list_add_tail().
Reported-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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This patch changes the log level if a plock is removed when interrupted
from debug to info. Additional it signals now that the plock entity was
removed to let the user know what's happening.
If on a dev_write() a pending plock cannot be find it will signal that
it might have been removed because wait interruption.
Before this patch there might be a "dev_write no op ..." info message
and the users can only guess that the plock was removed before because
the wait interruption. To be sure that is the case we log both messages
on the same log level.
Let both message be logged on info layer because it should not happened
a lot and if it happens it should be clear why the op was not found.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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This patch moves the return of FILE_LOCK_DEFERRED a little bit earlier
than checking afterwards again if the request was an asynchronous request.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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Lately the different casting between plock_op and plock_xop and list
holders which was involved showed some issues which were hard to see.
This patch removes the "plock_xop" structure and introduces a
"struct plock_async_data". This structure will be set in "struct plock_op"
in case of asynchronous lock handling as the original "plock_xop" was
made for. There is no need anymore to cast pointers around for
additional fields in case of asynchronous lock handling. As disadvantage
another allocation was introduces but only needed in the asynchronous
case which is currently only used in combination with nfs lockd.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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There are several sanity checks and recover handling if they occur in
the dlm plock handling. From my understanding those operation can't run
in parallel with any list manipulation which involved setting the list
holder of plock_op, if so we have a bug which this sanity check will
warn about. Previously if such sanity check occurred the dlm plock
handling was trying to recover from it by deleting the plock_op from a
list which the holder was set to. However there is a bug in the dlm
plock handling if this case ever happens. To make such bugs are more
visible for further investigations we add a WARN_ON() on those sanity
checks and remove the recovering handling because other possible side
effects.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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This patch fixes an invalid read showed by KASAN. A unlock will allocate a
"struct plock_op" and a followed send_op() will append it to a global
send_list data structure. In some cases a followed dev_read() moves it
to recv_list and dev_write() will cast it to "struct plock_xop" and access
fields which are only available in those structures. At this point an
invalid read happens by accessing those fields.
To fix this issue the "callback" field is moved to "struct plock_op" to
indicate that a cast to "plock_xop" is allowed and does the additional
"plock_xop" handling if set.
Example of the KASAN output which showed the invalid read:
[ 2064.296453] ==================================================================
[ 2064.304852] BUG: KASAN: slab-out-of-bounds in dev_write+0x52b/0x5a0 [dlm]
[ 2064.306491] Read of size 8 at addr ffff88800ef227d8 by task dlm_controld/7484
[ 2064.308168]
[ 2064.308575] CPU: 0 PID: 7484 Comm: dlm_controld Kdump: loaded Not tainted 5.14.0+ #9
[ 2064.310292] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 2064.311618] Call Trace:
[ 2064.312218] dump_stack_lvl+0x56/0x7b
[ 2064.313150] print_address_description.constprop.8+0x21/0x150
[ 2064.314578] ? dev_write+0x52b/0x5a0 [dlm]
[ 2064.315610] ? dev_write+0x52b/0x5a0 [dlm]
[ 2064.316595] kasan_report.cold.14+0x7f/0x11b
[ 2064.317674] ? dev_write+0x52b/0x5a0 [dlm]
[ 2064.318687] dev_write+0x52b/0x5a0 [dlm]
[ 2064.319629] ? dev_read+0x4a0/0x4a0 [dlm]
[ 2064.320713] ? bpf_lsm_kernfs_init_security+0x10/0x10
[ 2064.321926] vfs_write+0x17e/0x930
[ 2064.322769] ? __fget_light+0x1aa/0x220
[ 2064.323753] ksys_write+0xf1/0x1c0
[ 2064.324548] ? __ia32_sys_read+0xb0/0xb0
[ 2064.325464] do_syscall_64+0x3a/0x80
[ 2064.326387] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 2064.327606] RIP: 0033:0x7f807e4ba96f
[ 2064.328470] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 39 87 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 7c 87 f8 ff 48
[ 2064.332902] RSP: 002b:00007ffd50cfe6e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[ 2064.334658] RAX: ffffffffffffffda RBX: 000055cc3886eb30 RCX: 00007f807e4ba96f
[ 2064.336275] RDX: 0000000000000040 RSI: 00007ffd50cfe7e0 RDI: 0000000000000010
[ 2064.337980] RBP: 00007ffd50cfe7e0 R08: 0000000000000000 R09: 0000000000000001
[ 2064.339560] R10: 000055cc3886eb30 R11: 0000000000000293 R12: 000055cc3886eb80
[ 2064.341237] R13: 000055cc3886eb00 R14: 000055cc3886f590 R15: 0000000000000001
[ 2064.342857]
[ 2064.343226] Allocated by task 12438:
[ 2064.344057] kasan_save_stack+0x1c/0x40
[ 2064.345079] __kasan_kmalloc+0x84/0xa0
[ 2064.345933] kmem_cache_alloc_trace+0x13b/0x220
[ 2064.346953] dlm_posix_unlock+0xec/0x720 [dlm]
[ 2064.348811] do_lock_file_wait.part.32+0xca/0x1d0
[ 2064.351070] fcntl_setlk+0x281/0xbc0
[ 2064.352879] do_fcntl+0x5e4/0xfe0
[ 2064.354657] __x64_sys_fcntl+0x11f/0x170
[ 2064.356550] do_syscall_64+0x3a/0x80
[ 2064.358259] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 2064.360745]
[ 2064.361511] Last potentially related work creation:
[ 2064.363957] kasan_save_stack+0x1c/0x40
[ 2064.365811] __kasan_record_aux_stack+0xaf/0xc0
[ 2064.368100] call_rcu+0x11b/0xf70
[ 2064.369785] dlm_process_incoming_buffer+0x47d/0xfd0 [dlm]
[ 2064.372404] receive_from_sock+0x290/0x770 [dlm]
[ 2064.374607] process_recv_sockets+0x32/0x40 [dlm]
[ 2064.377290] process_one_work+0x9a8/0x16e0
[ 2064.379357] worker_thread+0x87/0xbf0
[ 2064.381188] kthread+0x3ac/0x490
[ 2064.383460] ret_from_fork+0x22/0x30
[ 2064.385588]
[ 2064.386518] Second to last potentially related work creation:
[ 2064.389219] kasan_save_stack+0x1c/0x40
[ 2064.391043] __kasan_record_aux_stack+0xaf/0xc0
[ 2064.393303] call_rcu+0x11b/0xf70
[ 2064.394885] dlm_process_incoming_buffer+0x47d/0xfd0 [dlm]
[ 2064.397694] receive_from_sock+0x290/0x770 [dlm]
[ 2064.399932] process_recv_sockets+0x32/0x40 [dlm]
[ 2064.402180] process_one_work+0x9a8/0x16e0
[ 2064.404388] worker_thread+0x87/0xbf0
[ 2064.406124] kthread+0x3ac/0x490
[ 2064.408021] ret_from_fork+0x22/0x30
[ 2064.409834]
[ 2064.410599] The buggy address belongs to the object at ffff88800ef22780
[ 2064.410599] which belongs to the cache kmalloc-96 of size 96
[ 2064.416495] The buggy address is located 88 bytes inside of
[ 2064.416495] 96-byte region [ffff88800ef22780, ffff88800ef227e0)
[ 2064.422045] The buggy address belongs to the page:
[ 2064.424635] page:00000000b6bef8bc refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xef22
[ 2064.428970] flags: 0xfffffc0000200(slab|node=0|zone=1|lastcpupid=0x1fffff)
[ 2064.432515] raw: 000fffffc0000200 ffffea0000d68b80 0000001400000014 ffff888001041780
[ 2064.436110] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
[ 2064.439813] page dumped because: kasan: bad access detected
[ 2064.442548]
[ 2064.443310] Memory state around the buggy address:
[ 2064.445988] ffff88800ef22680: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
[ 2064.449444] ffff88800ef22700: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
[ 2064.452941] >ffff88800ef22780: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
[ 2064.456383] ^
[ 2064.459386] ffff88800ef22800: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
[ 2064.462788] ffff88800ef22880: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
[ 2064.466239] ==================================================================
reproducer in python:
import argparse
import struct
import fcntl
import os
parser = argparse.ArgumentParser()
parser.add_argument('-f', '--file',
help='file to use fcntl, must be on dlm lock filesystem e.g. gfs2')
args = parser.parse_args()
f = open(args.file, 'wb+')
lockdata = struct.pack('hhllhh', fcntl.F_WRLCK,0,0,0,0,0)
fcntl.fcntl(f, fcntl.F_SETLK, lockdata)
lockdata = struct.pack('hhllhh', fcntl.F_UNLCK,0,0,0,0,0)
fcntl.fcntl(f, fcntl.F_SETLK, lockdata)
Fixes: 586759f03e2e ("gfs2: nfs lock support for gfs2")
Cc: stable@vger.kernel.org
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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Based on 1 normalized pattern(s):
this copyrighted material is made available to anyone wishing to use
modify copy or redistribute it subject to the terms and conditions
of the gnu general public license version 2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 44 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081038.653000175@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Since commit c69899a17ca4 "NFSv4: Update of VFS byte range lock must be
atomic with the stateid update", NFSv4 has been inserting locks in rpciod
worker context. The result is that the file_lock's fl_nspid is the
kworker's pid instead of the original userspace pid.
The fl_nspid is only used to represent the namespaced virtual pid number
when displaying locks or returning from F_GETLK. There's no reason to set
it for every inserted lock, since we can usually just look it up from
fl_pid. So, instead of looking up and holding struct pid for every lock,
let's just look up the virtual pid number from fl_pid when it is needed.
That means we can remove fl_nspid entirely.
The translaton and presentation of fl_pid should handle the following four
cases:
1 - F_GETLK on a remote file with a remote lock:
In this case, the filesystem should determine the l_pid to return here.
Filesystems should indicate that the fl_pid represents a non-local pid
value that should not be translated by returning an fl_pid <= 0.
2 - F_GETLK on a local file with a remote lock:
This should be the l_pid of the lock manager process, and translated.
3 - F_GETLK on a remote file with a local lock, and
4 - F_GETLK on a local file with a local lock:
These should be the translated l_pid of the local locking process.
Fuse was already doing the correct thing by translating the pid into the
caller's namespace. With this change we must update fuse to translate
to init's pid namespace, so that the locks API can then translate from
init's pid namespace into the pid namespace of the caller.
With this change, the locks API will expect that if a filesystem returns
a remote pid as opposed to a local pid for F_GETLK, that remote pid will
be <= 0. This signifies that the pid is remote, and the locks API will
forego translating that pid into the pid namespace of the local calling
process.
Finally, we convert remote filesystems to present remote pids using
negative numbers. Have lustre, 9p, ceph, cifs, and dlm negate the remote
pid returned for F_GETLK lock requests.
Since local pids will never be larger than PID_MAX_LIMIT (which is
currently defined as <= 4 million), but pid_t is an unsigned int, we
should have plenty of room to represent remote pids with negative
numbers if we assume that remote pid numbers are similarly limited.
If this is not the case, then we run the risk of having a remote pid
returned for which there is also a corresponding local pid. This is a
problem we have now, but this patch should reduce the chances of that
occurring, while also returning those remote pid numbers, for whatever
that may be worth.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm
Pull dlm update from David Teigland:
"This includes one simple fix to make posix locks interruptible by
signals in cases where a signal handler is used"
* tag 'dlm-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm:
dlm: make posix locks interruptible
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Replace wait_event_killable with wait_event_interruptible
so that a program waiting for a posix lock can be
interrupted by a signal. With the killable version,
a program was not interruptible by a signal if it
had a signal handler set for it, overriding the default
action of terminating the process.
Signed-off-by: Eric Ren <zren@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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Instead of having users check for FL_POSIX or FL_FLOCK to call the correct
locks API function, use the check within locks_lock_inode_wait(). This
allows for some later cleanup.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
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With well over 200+ users of this api, there are a mere 12 users that
actually checked the return value of this function. And all of them
really didn't do anything with that information as the system or module
was shutting down no matter what.
So stop pretending like it matters, and just return void from
misc_deregister(). If something goes wrong in the call, you will get a
WARNING splat in the syslog so you know how to fix up your driver.
Other than that, there's nothing that can go wrong.
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: Christine Caulfield <ccaulfie@redhat.com>
Cc: David Teigland <teigland@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This argument is always NULL so don't pass it around.
[jlayton: remove dependencies on previous patches in series]
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
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When the kernel clears flocks/plocks during close, it calls posix
unlock when there are flocks but no posix locks. Without this
patch, that unnecessary posix unlock is passed to userland
(dlm_controld), across the cluster, and back to the kernel.
This can create a lot of plock activity, even when no posix
locks had been used.
This patch copies the nfs approach, and skips the full posix
unlock if there is no plock found during the vfs unlock phase.
Signed-off-by: David Teigland <teigland@redhat.com>
|
|
Both the filesystem and the lock manager can associate operations with a
lock. Confusingly, one of them (fl_release_private) actually has the
same name in both operation structures.
It would save some confusion to give the lock-manager ops different
names.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
|
|
Allow processes blocked on plock requests to be interrupted
when they are killed. This leaves the problem of cleaning
up the lock state in userspace. This has three parts:
1. Add a flag to unlock operations sent to userspace
indicating the file is being closed. Userspace will
then look for and clear any waiting plock operations that
were abandoned by an interrupted process.
2. Queue an unlock-close operation (like in 1) to clean up
userspace from an interrupted plock request. This is needed
because the vfs will not send a cleanup-unlock if it sees no
locks on the file, which it won't if the interrupted operation
was the only one.
3. Do not use replies from userspace for unlock-close operations
because they are unnecessary (they are just cleaning up for the
process which did not make an unlock call). This also simplifies
the new unlock-close generated from point 2.
Signed-off-by: David Teigland <teigland@redhat.com>
|
|
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.
The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.
New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.
The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.
Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.
Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.
===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}
@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}
@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}
@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}
@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};
@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};
@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};
@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};
@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};
// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};
@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};
// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};
// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};
// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};
@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};
// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////
@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};
@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};
@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};
@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
|
|
implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
dlm: always use GFP_NOFS
|
|
That is "success", "unknown", "through", "performance", "[re|un]mapping"
, "access", "default", "reasonable", "[con]currently", "temperature"
, "channel", "[un]used", "application", "example","hierarchy", "therefore"
, "[over|under]flow", "contiguous", "threshold", "enough" and others.
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
|
|
Replace all GFP_KERNEL and ls_allocation with GFP_NOFS.
ls_allocation would be GFP_KERNEL for userland lockspaces
and GFP_NOFS for file system lockspaces.
It was discovered that any lockspaces on the system can
affect all others by triggering memory reclaim in the
file system which could in turn call back into the dlm
to acquire locks, deadlocking dlm threads that were
shared by all lockspaces, like dlm_recv.
Signed-off-by: David Teigland <teigland@redhat.com>
|
|
Fix a regression from the original addition of nfs lock support
586759f03e2e9031ac5589912a51a909ed53c30a. When a synchronous
(non-nfs) plock completes, the waiting thread will wake up and
free the op struct. This races with the user thread in
dev_write() which goes on to read the op's callback field to
check if the lock is async and needs a callback. This check
can happen on the freed op. The fix is to note the callback
value before the op can be freed.
Signed-off-by: David Teigland <teigland@redhat.com>
|
|
dlm_posix_get fills out the relevant fields in the file_lock before
returning when there is a lock conflict, but doesn't clean out any of
the other fields in the file_lock.
When nfsd does a NFSv4 lockt call, it sets the fl_lmops to
nfsd_posix_mng_ops before calling the lower fs. When the lock comes back
after testing a lock on GFS2, it still has that field set. This confuses
nfsd into thinking that the file_lock is a nfsd4 lock.
Fix this by making DLM reinitialize the file_lock before copying the
fields from the conflicting lock.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
|
|
We should use the original copy of the file_lock, fl, instead
of the copy, flc in the lockd notify callback. The range in flc has
been modified by posix_lock_file(), so it will not match a copy of the
lock in lockd.
Signed-off-by: David Teigland <teigland@redhat.com>
|
|
Use a special error value FILE_LOCK_DEFERRED to mean that a locking
operation returned asynchronously. This is returned by
posix_lock_file() for sleeping locks to mean that the lock has been
queued on the block list, and will be woken up when it might become
available and needs to be retried (either fl_lmops->fl_notify() is
called or fl_wait is woken up).
f_op->lock() to mean either the above, or that the filesystem will
call back with fl_lmops->fl_grant() when the result of the locking
operation is known. The filesystem can do this for sleeping as well
as non-sleeping locks.
This is to make sure, that return values of -EAGAIN and -EINPROGRESS by
filesystems are not mistaken to mean an asynchronous locking.
This also makes error handling in fs/locks.c and lockd/svclock.c slightly
cleaner.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: David Teigland <teigland@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The return value on writes to the plock device should be
the number of bytes written. It was returning 0 instead
when an nfs lock callback was involved.
Reported-by: Nathan Straz <nstraz@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
|
|
Move the code that handles cluster posix locks from gfs2 into the dlm
so that it can be used by both gfs2 and ocfs2.
Signed-off-by: David Teigland <teigland@redhat.com>
|
