The series to add memcg accounting to KVM allocations[1] states:
There are many KVM kernel memory allocations which are tied to the
life of the VM process and should be charged to the VM process's
cgroup.
While it is correct to account KVM kernel allocations to the cgroup of
the process that created the VM, it's technically incorrect to state
that the KVM kernel memory allocations are tied to the life of the VM
process. This is because the VM itself, i.e. struct kvm, is not tied to
the life of the process which created it, rather it is tied to the life
of its associated file descriptor. In other words, kvm_destroy_vm() is
not invoked until fput() decrements its associated file's refcount to
zero. A simple example is to fork() in Qemu and have the child sleep
indefinitely; kvm_destroy_vm() isn't called until Qemu closes its file
descriptor *and* the rogue child is killed.
The allocations are guaranteed to be *accounted* to the process which
created the VM, but only because KVM's per-{VM,vCPU} ioctls reject the
ioctl() with -EIO if kvm->mm != current->mm. I.e. the child can keep
the VM "alive" but can't do anything useful with its reference.
Note that because 'struct kvm' also holds a reference to the mm_struct
of its owner, the above behavior also applies to userspace allocations.
Given that mucking with a VM's file descriptor can lead to subtle and
undesirable behavior, e.g. memcg charges persisting after a VM is shut
down, explicitly document a VM's lifecycle and its impact on the VM's
resources.
Alternatively, KVM could aggressively free resources when the creating
process exits, e.g. via mmu_notifier->release(). However, mmu_notifier
isn't guaranteed to be available, and freeing resources when the creator
exits is likely to be error prone and fragile as KVM would need to
ensure that it only freed resources that are truly out of reach. In
practice, the existing behavior shouldn't be problematic as a properly
configured system will prevent a child process from being moved out of
the appropriate cgroup hierarchy, i.e. prevent hiding the process from
the OOM killer, and will prevent an unprivileged user from being able to
to hold a reference to struct kvm via another method, e.g. debugfs.
[1]https://patchwork.kernel.org/patch/10806707/
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently we only drop the mmap_sem if there is contention on the page
lock. The idea is that we issue readahead and then go to lock the page
while it is under IO and we want to not hold the mmap_sem during the IO.
The problem with this is the assumption that the readahead does anything.
In the case that the box is under extreme memory or IO pressure we may end
up not reading anything at all for readahead, which means we will end up
reading in the page under the mmap_sem.
Even if the readahead does something, it could get throttled because of io
pressure on the system and the process is in a lower priority cgroup.
Holding the mmap_sem while doing IO is problematic because it can cause
system-wide priority inversions. Consider some large company that does a
lot of web traffic. This large company has load balancing logic in it's
core web server, cause some engineer thought this was a brilliant plan.
This load balancing logic gets statistics from /proc about the system,
which trip over processes mmap_sem for various reasons. Now the web
server application is in a protected cgroup, but these other processes may
not be, and if they are being throttled while their mmap_sem is held we'll
stall, and cause this nice death spiral.
Instead rework filemap fault path to drop the mmap sem at any point that
we may do IO or block for an extended period of time. This includes while
issuing readahead, locking the page, or needing to call ->readpage because
readahead did not occur. Then once we have a fully uptodate page we can
return with VM_FAULT_RETRY and come back again to find our nicely in-cache
page that was gotten outside of the mmap_sem.
This patch also adds a new helper for locking the page with the mmap_sem
dropped. This doesn't make sense currently as generally speaking if the
page is already locked it'll have been read in (unless there was an error)
before it was unlocked. However a forthcoming patchset will change this
with the ability to abort read-ahead bio's if necessary, making it more
likely that we could contend for a page lock and still have a not uptodate
page. This allows us to deal with this case by grabbing the lock and
issuing the IO without the mmap_sem held, and then returning
VM_FAULT_RETRY to come back around.
[josef@toxicpanda.com: v6]
Link: http://lkml.kernel.org/r/20181212152757.10017-1-josef@toxicpanda.com
[kirill@shutemov.name: fix race in filemap_fault()]
Link: http://lkml.kernel.org/r/20181228235106.okk3oastsnpxusxs@kshutemo-mobl1
[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/20181211173801.29535-4-josef@toxicpanda.com
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: syzbot+b437b5a429d680cf2217@syzkaller.appspotmail.com
Cc: Dave Chinner <david@fromorbit.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "drop the mmap_sem when doing IO in the fault path", v6.
Now that we have proper isolation in place with cgroups2 we have started
going through and fixing the various priority inversions. Most are all
gone now, but this one is sort of weird since it's not necessarily a
priority inversion that happens within the kernel, but rather because of
something userspace does.
We have giant applications that we want to protect, and parts of these
giant applications do things like watch the system state to determine how
healthy the box is for load balancing and such. This involves running
'ps' or other such utilities. These utilities will often walk
/proc/<pid>/whatever, and these files can sometimes need to
down_read(&task->mmap_sem). Not usually a big deal, but we noticed when
we are stress testing that sometimes our protected application has latency
spikes trying to get the mmap_sem for tasks that are in lower priority
cgroups.
This is because any down_write() on a semaphore essentially turns it into
a mutex, so even if we currently have it held for reading, any new readers
will not be allowed on to keep from starving the writer. This is fine,
except a lower priority task could be stuck doing IO because it has been
throttled to the point that its IO is taking much longer than normal. But
because a higher priority group depends on this completing it is now stuck
behind lower priority work.
In order to avoid this particular priority inversion we want to use the
existing retry mechanism to stop from holding the mmap_sem at all if we
are going to do IO. This already exists in the read case sort of, but
needed to be extended for more than just grabbing the page lock. With
io.latency we throttle at submit_bio() time, so the readahead stuff can
block and even page_cache_read can block, so all these paths need to have
the mmap_sem dropped.
The other big thing is ->page_mkwrite. btrfs is particularly shitty here
because we have to reserve space for the dirty page, which can be a very
expensive operation. We use the same retry method as the read path, and
simply cache the page and verify the page is still setup properly the next
pass through ->page_mkwrite().
I've tested these patches with xfstests and there are no regressions.
This patch (of 3):
If we do not have a page at filemap_fault time we'll do this weird forced
page_cache_read thing to populate the page, and then drop it again and
loop around and find it. This makes for 2 ways we can read a page in
filemap_fault, and it's not really needed. Instead add a FGP_FOR_MMAP
flag so that pagecache_get_page() will return a unlocked page that's in
pagecache. Then use the normal page locking and readpage logic already in
filemap_fault. This simplifies the no page in page cache case
significantly.
[akpm@linux-foundation.org: fix comment text]
[josef@toxicpanda.com: don't unlock null page in FGP_FOR_MMAP case]
Link: http://lkml.kernel.org/r/20190312201742.22935-1-josef@toxicpanda.com
Link: http://lkml.kernel.org/r/20181211173801.29535-2-josef@toxicpanda.com
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Tell userspace about whether a particular hardware workaround for
one of the Spectre vulnerabilities is available, so that userspace
can inform the guest.
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Merge tag 'kvm-ppc-next-5.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD
Third PPC KVM update for 5.1
- Tell userspace about whether a particular hardware workaround for
one of the Spectre vulnerabilities is available, so that userspace
can inform the guest.
It's safe to assume Paolo and Radim are maintaining the KVM selftests
given that the vast majority of commits have their SOBs. Play nice
with get_maintainers and make it official.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This reverts commit 71883a62fc.
The above commit contains an optimization to kvm_zap_gfn_range which
uses gfn-limited TLB flushes, if enabled. If using these limited flushes,
kvm_zap_gfn_range passes lock_flush_tlb=false to slot_handle_level_range
which creates a race when the function unlocks to call cond_resched.
See an example of this race below:
CPU 0 CPU 1 CPU 3
// zap_direct_gfn_range
mmu_lock()
// *ptep == pte_1
*ptep = 0
if (lock_flush_tlb)
flush_tlbs()
mmu_unlock()
// In invalidate range
// MMU notifier
mmu_lock()
if (pte != 0)
*ptep = 0
flush = true
if (flush)
flush_remote_tlbs()
mmu_unlock()
return
// Host MM reallocates
// page previously
// backing guest memory.
// Guest accesses
// invalid page
// through pte_1
// in its TLB!!
Tested: Ran all kvm-unit-tests on a Intel Haswell machine with and
without this patch. The patch introduced no new failures.
Signed-off-by: Ben Gardon <bgardon@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use the request tag for logging instead of the scsi command serial
number.
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
[jejb: fix commit oneliner]
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Now that we're using the xdr_stream functions to decode the header,
the test for the minimum reply length is redundant.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Handle the SYSTEM_ERR rpc error by retrying the RPC call as if it
were a garbage argument.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Ensure that when the "garbage args" case falls through, we do set
an error of EIO.
Fixes: a0584ee9ae ("SUNRPC: Use struct xdr_stream when decoding...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
When the socket is closed, we currently send an EAGAIN error to all
pending requests in order to ask them to retransmit. Use ENOTCONN
instead, to ensure that they try to reconnect before attempting to
transmit.
This also helps SOFTCONN tasks to behave correctly in this
situation.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We must at minimum allocate enough memory to be able to see any auth
errors in the reply from the server.
Fixes: 2c94b8eca1 ("SUNRPC: Use au_rslack when computing reply...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the server sends a reply that is larger than the pre-allocated
buffer, then the current code may fail to register how much of
the stream that it has finished reading. This again can lead to
hangs.
Fixes: e92053a52e ("SUNRPC: Handle zero length fragments correctly")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Add a non-NULL check to fix potential NULL pointer dereference
Cleanup code to call function once.
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Fixes: 2bf9a0a127 ('iommu/amd: Add iommu support for ACPI HID devices')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
The XEN balloon driver - in contrast to other balloon drivers - allows
to map some inflated pages to user space. Such pages are allocated via
alloc_xenballooned_pages() and freed via free_xenballooned_pages().
The pfn space of these allocated pages is used to map other things
by the hypervisor using hypercalls.
Pages marked with PG_offline must never be mapped to user space (as
this page type uses the mapcount field of struct pages).
So what we can do is, clear/set PG_offline when allocating/freeing an
inflated pages. This way, most inflated pages can be excluded by
dumping tools and the "reused for other purpose" balloon pages are
correctly not marked as PG_offline.
Fixes: 77c4adf6a6 (xen/balloon: mark inflated pages PG_offline)
Reported-by: Julien Grall <julien.grall@arm.com>
Tested-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Guenter reported a build warning for CONFIG_CPU_SUP_INTEL=n:
> With allmodconfig-CONFIG_CPU_SUP_INTEL, this patch results in:
>
> In file included from arch/x86/events/amd/core.c:8:0:
> arch/x86/events/amd/../perf_event.h:1036:45: warning: ‘struct cpu_hw_event’ declared inside parameter list will not be visible outside of this definition or declaration
> static inline int intel_cpuc_prepare(struct cpu_hw_event *cpuc, int cpu)
While harmless (an unsed pointer is an unused pointer, no matter the type)
it needs fixing.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: d01b1f96a8 ("perf/x86/intel: Make cpuc allocations consistent")
Link: http://lkml.kernel.org/r/20190315081410.GR5996@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Through:
validate_event()
x86_pmu.get_event_constraints(.idx=-1)
tfa_get_event_constraints()
dyn_constraint()
cpuc->constraint_list[-1] is used, which is an obvious out-of-bound access.
In this case, simply skip the TFA constraint code, there is no event
constraint with just PMC3, therefore the code will never result in the
empty set.
Fixes: 400816f60c ("perf/x86/intel: Implement support for TSX Force Abort")
Reported-by: Tony Jones <tonyj@suse.com>
Reported-by: "DSouza, Nelson" <nelson.dsouza@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tony Jones <tonyj@suse.com>
Tested-by: "DSouza, Nelson" <nelson.dsouza@intel.com>
Cc: eranian@google.com
Cc: jolsa@redhat.com
Cc: stable@kernel.org
Link: https://lkml.kernel.org/r/20190314130705.441549378@infradead.org
We have a customer reporting crashes in lock_get_status() with many
"Leaked POSIX lock" messages preceeding the crash.
Leaked POSIX lock on dev=0x0:0x56 ...
Leaked POSIX lock on dev=0x0:0x56 ...
Leaked POSIX lock on dev=0x0:0x56 ...
Leaked POSIX lock on dev=0x0:0x53 ...
Leaked POSIX lock on dev=0x0:0x53 ...
Leaked POSIX lock on dev=0x0:0x53 ...
Leaked POSIX lock on dev=0x0:0x53 ...
POSIX: fl_owner=ffff8900e7b79380 fl_flags=0x1 fl_type=0x1 fl_pid=20709
Leaked POSIX lock on dev=0x0:0x4b ino...
Leaked locks on dev=0x0:0x4b ino=0xf911400000029:
POSIX: fl_owner=ffff89f41c870e00 fl_flags=0x1 fl_type=0x1 fl_pid=19592
stack segment: 0000 [#1] SMP
Modules linked in: binfmt_misc msr tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag rpcsec_gss_krb5 arc4 ecb auth_rpcgss nfsv4 md4 nfs nls_utf8 lockd grace cifs sunrpc ccm dns_resolver fscache af_packet iscsi_ibft iscsi_boot_sysfs vmw_vsock_vmci_transport vsock xfs libcrc32c sb_edac edac_core crct10dif_pclmul crc32_pclmul ghash_clmulni_intel drbg ansi_cprng vmw_balloon aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd joydev pcspkr vmxnet3 i2c_piix4 vmw_vmci shpchp fjes processor button ac btrfs xor raid6_pq sr_mod cdrom ata_generic sd_mod ata_piix vmwgfx crc32c_intel drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm serio_raw ahci libahci drm libata vmw_pvscsi sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4
Supported: Yes
CPU: 6 PID: 28250 Comm: lsof Not tainted 4.4.156-94.64-default #1
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
task: ffff88a345f28740 ti: ffff88c74005c000 task.ti: ffff88c74005c000
RIP: 0010:[<ffffffff8125dcab>] [<ffffffff8125dcab>] lock_get_status+0x9b/0x3b0
RSP: 0018:ffff88c74005fd90 EFLAGS: 00010202
RAX: ffff89bde83e20ae RBX: ffff89e870003d18 RCX: 0000000049534f50
RDX: ffffffff81a3541f RSI: ffffffff81a3544e RDI: ffff89bde83e20ae
RBP: 0026252423222120 R08: 0000000020584953 R09: 000000000000ffff
R10: 0000000000000000 R11: ffff88c74005fc70 R12: ffff89e5ca7b1340
R13: 00000000000050e5 R14: ffff89e870003d30 R15: ffff89e5ca7b1340
FS: 00007fafd64be800(0000) GS:ffff89f41fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001c80018 CR3: 000000a522048000 CR4: 0000000000360670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
0000000000000208 ffffffff81a3d6b6 ffff89e870003d30 ffff89e870003d18
ffff89e5ca7b1340 ffff89f41738d7c0 ffff89e870003d30 ffff89e5ca7b1340
ffffffff8125e08f 0000000000000000 ffff89bc22b67d00 ffff88c74005ff28
Call Trace:
[<ffffffff8125e08f>] locks_show+0x2f/0x70
[<ffffffff81230ad1>] seq_read+0x251/0x3a0
[<ffffffff81275bbc>] proc_reg_read+0x3c/0x70
[<ffffffff8120e456>] __vfs_read+0x26/0x140
[<ffffffff8120e9da>] vfs_read+0x7a/0x120
[<ffffffff8120faf2>] SyS_read+0x42/0xa0
[<ffffffff8161cbc3>] entry_SYSCALL_64_fastpath+0x1e/0xb7
When Linux closes a FD (close(), close-on-exec, dup2(), ...) it calls
filp_close() which also removes all posix locks.
The lock struct is initialized like so in filp_close() and passed
down to cifs
...
lock.fl_type = F_UNLCK;
lock.fl_flags = FL_POSIX | FL_CLOSE;
lock.fl_start = 0;
lock.fl_end = OFFSET_MAX;
...
Note the FL_CLOSE flag, which hints the VFS code that this unlocking
is done for closing the fd.
filp_close()
locks_remove_posix(filp, id);
vfs_lock_file(filp, F_SETLK, &lock, NULL);
return filp->f_op->lock(filp, cmd, fl) => cifs_lock()
rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock, xid);
rc = server->ops->mand_unlock_range(cfile, flock, xid);
if (flock->fl_flags & FL_POSIX && !rc)
rc = locks_lock_file_wait(file, flock)
Notice how we don't call locks_lock_file_wait() which does the
generic VFS lock/unlock/wait work on the inode if rc != 0.
If we are closing the handle, the SMB server is supposed to remove any
locks associated with it. Similarly, cifs.ko frees and wakes up any
lock and lock waiter when closing the file:
cifs_close()
cifsFileInfo_put(file->private_data)
/*
* Delete any outstanding lock records. We'll lose them when the file
* is closed anyway.
*/
down_write(&cifsi->lock_sem);
list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
list_del(&li->llist);
cifs_del_lock_waiters(li);
kfree(li);
}
list_del(&cifs_file->llist->llist);
kfree(cifs_file->llist);
up_write(&cifsi->lock_sem);
So we can safely ignore unlocking failures in cifs_lock() if they
happen with the FL_CLOSE flag hint set as both the server and the
client take care of it during the actual closing.
This is not a proper fix for the unlocking failure but it's safe and
it seems to prevent the lock leakages and crashes the customer
experiences.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
For debugging purposes we often have to be able to query
additional information only available via SMB3 FSCTL
from the server from user space tools (e.g. like
cifs-utils's smbinfo). See MS-FSCC and MS-SMB2 protocol
specifications for more details.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
smb2_set_sparse does not return -errno, it returns a boolean where
true means success.
Change this to just ignore the return value just like the other callsites.
Additionally add code to handle the case where we must set the file sparse
and possibly also extending it.
Fixes xfstests: generic/236 generic/350 generic/420
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
As Sergey Senozhatsky pointed out __constant_cpu_to_le32()
is misspelled in a few definitions in the list of status
codes smb2status.h as __constanst_cpu_to_le32()
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
This cleanup removes cifs specific code from SMB2/SMB3 code paths
which is cleaner and easier to maintain as the code to handle
special files is improved. Below is an example creating special files
using 'sfu' mount option over SMB3 to Windows (with this patch)
(Note that to Samba server, support for saving dos attributes
has to be enabled for the SFU mount option to work).
In the future this will also make implementation of creating
special files as reparse points easier (as Windows NFS server does
for example).
root@smf-Thinkpad-P51:~# stat -c "%F" /mnt2/char
character special file
root@smf-Thinkpad-P51:~# stat -c "%F" /mnt2/block
block special file
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Detected by CoverityScan CID#1438719 ("Unused Value")
buf is reset again before being used so these two lines of code
are useless.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
The passthrough queries from user space tools like smbinfo can be either
SMB3 QUERY_INFO or SMB3 FSCTL, but we are not checking for the latter.
Temporarily we return EOPNOTSUPP for SMB3 FSCTL passthrough requests
but once compounding fsctls is fixed can enable.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Can be helpful in debugging various xfstests that are currently
skipped or failing due to missing features in our current
implementation of fallocate.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
This allows fallocate -z to work against a Windows2016 share.
This is due to the SMB3 ZERO_RANGE command does not modify the filesize.
To address this we will now append a compounded SET-INFO to update the
end-of-file information.
This brings xfstests generic/469 closer to working against a windows share.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Define an _init() and a _free() function for SMB2_init so that we will
be able to use it with compounds.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Adds trace points for enter and exit (done vs. error) for:
compounded query and setinfo, hardlink, rename,
mkdir, rmdir, set_eof, delete (unlink)
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
When we open the shared root handle also ask for FILE_ALL_INFORMATION since
we can do this at zero cost as part of a compound.
Cache this information as long as the lease is held and return and serve any
future requests from cache.
This allows us to serve "stat /<mountpoint>" directly from cache and avoid
a network roundtrip. Since clients often want to do this quite a lot
this improve performance slightly.
As an example: xfstest generic/533 performs 43 stat operations on the root
of the share while it is run. Which are eliminated with this patch.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
It can be helpful for debugging. According to MS-FSCC:
"A 32-bit unsigned integer that contains the serial number of the
volume. The serial number is an opaque value generated by the file
system at format time"
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Since we can now wait for multiple requests atomically in
wait_for_free_request() we can now greatly simplify the handling
of the credits in this function.
This fixes a potential deadlock where many concurrent compound requests
could each have reserved 1 or 2 credits each but are all blocked
waiting for the final credits they need to be able to issue the requests
to the server.
Set a default timeout of 60 seconds for compounded requests.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
To help debug credit starvation problems where we timeout
waiting for server to grant the client credits.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
When the server required encryption (but we didn't connect to it with the
"seal" mount option) we weren't displaying in /proc/fs/cifs/DebugData that
the tcon for that share was encrypted. Similarly we were not displaying
that signing was required when ses->sign was enabled (we only
checked ses->server->sign). This makes it easier to debug when in
fact the connection is signed (or sealed), whether for performance
or security questions.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
A negative timeout is the same as the current behaviour, i.e. no timeout.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reserve the last MAX_COMPOUND credits for any request asking for >1 credit.
This is to prevent future compound requests from becoming starved while waiting
for potentially many requests is there is a large number of concurrent
singe-credit requests.
However, we need to protect from servers that are very slow to hand out
new credits on new sessions so we only do this IFF there are 2*MAX_COMPOUND
(arbitrary) credits already in flight.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Change wait_for_free_credits() to allow waiting for >=1 credits instead of just
a single credit.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
and compute timeout and optyp from it.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Since alloc_trace_*probe() returns -EINVAL only if !event && !group,
it should not happen in trace_*probe_create(). If we catch that case
there is a bug. So use WARN_ON_ONCE() instead of pr_info().
Link: http://lkml.kernel.org/r/155253785078.14922.16902223633734601469.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Ensure given name of event is not too long when parsing it,
and fix to update event name offset correctly when the group
name is given. For example, this makes probe event to check
the "p:foo/" error case correctly.
Link: http://lkml.kernel.org/r/155253782046.14922.14724124823730168629.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Check maxactive on kprobe error case, because maxactive
is only for kretprobe, not for kprobe. Also, maxactive
should not be 0, it should be at least 1.
Link: http://lkml.kernel.org/r/155253780952.14922.15784129810238750331.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Merge misc patches from Andrew Morton:
- a little bit more MM
- a few fixups
[ The "little bit more MM" is actually just one of the three patches
Andrew sent for mm/filemap.c, I'm still mulling over two more of them
from Josef Bacik - Linus ]
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
include/linux/swap.h: use offsetof() instead of custom __swapoffset macro
tools/testing/selftests/proc/proc-pid-vm.c: test with vsyscall in mind
zram: default to lzo-rle instead of lzo
filemap: pass vm_fault to the mmap ra helpers
Use offsetof() to calculate offset of a field to take advantage of
compiler built-in version when possible, and avoid UBSAN warning when
compiling with Clang:
UBSAN: Undefined behaviour in mm/swapfile.c:3010:38
member access within null pointer of type 'union swap_header'
CPU: 6 PID: 1833 Comm: swapon Tainted: G S 4.19.23 #43
Call trace:
dump_backtrace+0x0/0x194
show_stack+0x20/0x2c
__dump_stack+0x20/0x28
dump_stack+0x70/0x94
ubsan_epilogue+0x14/0x44
ubsan_type_mismatch_common+0xf4/0xfc
__ubsan_handle_type_mismatch_v1+0x34/0x54
__se_sys_swapon+0x654/0x1084
__arm64_sys_swapon+0x1c/0x24
el0_svc_common+0xa8/0x150
el0_svc_compat_handler+0x2c/0x38
el0_svc_compat+0x8/0x18
Link: http://lkml.kernel.org/r/20190312081902.223764-1-pihsun@chromium.org
Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lzo-rle gives higher performance and similar compression ratios to lzo.
Link: http://lkml.kernel.org/r/20190205155944.16007-4-dave.rodgman@arm.com
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
