We added CONFIG_MANDATORY_FILE_LOCKING in 2015, and soon after turned it
off in Fedora and RHEL8. Several other distros have followed suit.
I've heard of one problem in all that time: Someone migrated from an
older distro that supported "-o mand" to one that didn't, and the host
had a fstab entry with "mand" in it which broke on reboot. They didn't
actually _use_ mandatory locking so they just removed the mount option
and moved on.
This patch rips out mandatory locking support wholesale from the kernel,
along with the Kconfig option and the Documentation file. It also
changes the mount code to ignore the "mand" mount option instead of
erroring out, and to throw a big, ugly warning.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
including a fix to grant read delegations for files open for
writing.
-----BEGIN PGP SIGNATURE-----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=HB+N
-----END PGP SIGNATURE-----
Merge tag 'nfsd-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull more nfsd updates from Chuck Lever:
"Additional fixes and clean-ups for NFSD since tags/nfsd-5.13,
including a fix to grant read delegations for files open for writing"
* tag 'nfsd-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
SUNRPC: Fix null pointer dereference in svc_rqst_free()
SUNRPC: fix ternary sign expansion bug in tracing
nfsd: Fix fall-through warnings for Clang
nfsd: grant read delegations to clients holding writes
nfsd: reshuffle some code
nfsd: track filehandle aliasing in nfs4_files
nfsd: hash nfs4_files by inode number
nfsd: ensure new clients break delegations
nfsd: removed unused argument in nfsd_startup_generic()
nfsd: remove unused function
svcrdma: Pass a useful error code to the send_err tracepoint
svcrdma: Rename goto labels in svc_rdma_sendto()
svcrdma: Don't leak send_ctxt on Send errors
-----BEGIN PGP SIGNATURE-----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=88Qz
-----END PGP SIGNATURE-----
Merge tag 'locks-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux
Pull file locking updates from Jeff Layton:
"When we reworked the blocked locks into a tree structure instead of a
flat list a few releases ago, we lost the ability to see all of the
file locks in /proc/locks. Luo's patch fixes it to dump out all of the
blocked locks instead, which restores the full output.
This changes the format of /proc/locks as the blocked locks are shown
at multiple levels of indentation now, but lslocks (the only common
program I've ID'ed that scrapes this info) seems to be OK with that.
Tian also contributed a small patch to remove a useless assignment"
* tag 'locks-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
fs/locks: remove useless assignment in fcntl_getlk
fs/locks: print full locks information
It's OK to grant a read delegation to a client that holds a write,
as long as it's the only client holding the write.
We originally tried to do this in commit 94415b06eb ("nfsd4: a
client's own opens needn't prevent delegations"), which had to be
reverted in commit 6ee65a7730 ("Revert "nfsd4: a client's own
opens needn't prevent delegations"").
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Function parameter 'cmd' is rewritten with unused value at locks.c
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Commit fd7732e033 ("fs/locks: create a tree of dependent requests.")
has put blocked locks into a tree.
So, with a for loop, we can't check all locks information.
To solve this problem, we should traverse the tree.
Signed-off-by: Luo Longjun <luolongjun@huawei.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
This reverts commit 94415b06eb.
That commit claimed to allow a client to get a read delegation when it
was the only writer. Actually it allowed a client to get a read
delegation when *any* client has a write open!
The main problem is that it's depending on nfs4_clnt_odstate structures
that are actually only maintained for pnfs exports.
This causes clients to miss writes performed by other clients, even when
there have been intervening closes and opens, violating close-to-open
cache consistency.
We can do this a different way, but first we should just revert this.
I've added pynfs 4.1 test DELEG19 to test for this, as I should have
done originally!
Cc: stable@vger.kernel.org
Reported-by: Timo Rothenpieler <timo@rothenpieler.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Pull execve updates from Eric Biederman:
"This set of changes ultimately fixes the interaction of posix file
lock and exec. Fundamentally most of the change is just moving where
unshare_files is called during exec, and tweaking the users of
files_struct so that the count of files_struct is not unnecessarily
played with.
Along the way fcheck and related helpers were renamed to more
accurately reflect what they do.
There were also many other small changes that fell out, as this is the
first time in a long time much of this code has been touched.
Benchmarks haven't turned up any practical issues but Al Viro has
observed a possibility for a lot of pounding on task_lock. So I have
some changes in progress to convert put_files_struct to always rcu
free files_struct. That wasn't ready for the merge window so that will
have to wait until next time"
* 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
exec: Move io_uring_task_cancel after the point of no return
coredump: Document coredump code exclusively used by cell spufs
file: Remove get_files_struct
file: Rename __close_fd_get_file close_fd_get_file
file: Replace ksys_close with close_fd
file: Rename __close_fd to close_fd and remove the files parameter
file: Merge __alloc_fd into alloc_fd
file: In f_dupfd read RLIMIT_NOFILE once.
file: Merge __fd_install into fd_install
proc/fd: In fdinfo seq_show don't use get_files_struct
bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu
proc/fd: In proc_readfd_common use task_lookup_next_fd_rcu
file: Implement task_lookup_next_fd_rcu
kcmp: In get_file_raw_ptr use task_lookup_fd_rcu
proc/fd: In tid_fd_mode use task_lookup_fd_rcu
file: Implement task_lookup_fd_rcu
file: Rename fcheck lookup_fd_rcu
file: Replace fcheck_files with files_lookup_fd_rcu
file: Factor files_lookup_fd_locked out of fcheck_files
file: Rename __fcheck_files to files_lookup_fd_raw
...
To make it easy to tell where files->file_lock protection is being
used when looking up a file create files_lookup_fd_locked. Only allow
this function to be called with the file_lock held.
Update the callers of fcheck and fcheck_files that are called with the
files->file_lock held to call files_lookup_fd_locked instead.
Hopefully this makes it easier to quickly understand what is going on.
The need for better names became apparent in the last round of
discussion of this set of changes[1].
[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-8-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
When the sum of fl->fl_start and l->l_len overflows,
UBSAN shows the following warning:
UBSAN: Undefined behaviour in fs/locks.c:482:29
signed integer overflow: 2 + 9223372036854775806
cannot be represented in type 'long long int'
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xe4/0x14e lib/dump_stack.c:118
ubsan_epilogue+0xe/0x81 lib/ubsan.c:161
handle_overflow+0x193/0x1e2 lib/ubsan.c:192
flock64_to_posix_lock fs/locks.c:482 [inline]
flock_to_posix_lock+0x595/0x690 fs/locks.c:515
fcntl_setlk+0xf3/0xa90 fs/locks.c:2262
do_fcntl+0x456/0xf60 fs/fcntl.c:387
__do_sys_fcntl fs/fcntl.c:483 [inline]
__se_sys_fcntl fs/fcntl.c:468 [inline]
__x64_sys_fcntl+0x12d/0x180 fs/fcntl.c:468
do_syscall_64+0xc8/0x5a0 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Fix it by parenthesizing 'l->l_len - 1'.
Signed-off-by: Luo Meng <luomeng12@huawei.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
- Support for user extended attributes on NFS (RFC 8276)
- Further reduce unnecessary NFSv4 delegation recalls
Notable fixes:
- Fix recent krb5p regression
- Address a few resource leaks and a rare NULL dereference
Other:
- De-duplicate RPC/RDMA error handling and other utility functions
- Replace storage and display of kernel memory addresses by tracepoints
-----BEGIN PGP SIGNATURE-----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=OEpF
-----END PGP SIGNATURE-----
Merge tag 'nfsd-5.9' of git://git.linux-nfs.org/projects/cel/cel-2.6
Pull NFS server updates from Chuck Lever:
"Highlights:
- Support for user extended attributes on NFS (RFC 8276)
- Further reduce unnecessary NFSv4 delegation recalls
Notable fixes:
- Fix recent krb5p regression
- Address a few resource leaks and a rare NULL dereference
Other:
- De-duplicate RPC/RDMA error handling and other utility functions
- Replace storage and display of kernel memory addresses by tracepoints"
* tag 'nfsd-5.9' of git://git.linux-nfs.org/projects/cel/cel-2.6: (38 commits)
svcrdma: CM event handler clean up
svcrdma: Remove transport reference counting
svcrdma: Fix another Receive buffer leak
SUNRPC: Refresh the show_rqstp_flags() macro
nfsd: netns.h: delete a duplicated word
SUNRPC: Fix ("SUNRPC: Add "@len" parameter to gss_unwrap()")
nfsd: avoid a NULL dereference in __cld_pipe_upcall()
nfsd4: a client's own opens needn't prevent delegations
nfsd: Use seq_putc() in two functions
svcrdma: Display chunk completion ID when posting a rw_ctxt
svcrdma: Record send_ctxt completion ID in trace_svcrdma_post_send()
svcrdma: Introduce Send completion IDs
svcrdma: Record Receive completion ID in svc_rdma_decode_rqst
svcrdma: Introduce Receive completion IDs
svcrdma: Introduce infrastructure to support completion IDs
svcrdma: Add common XDR encoders for RDMA and Read segments
svcrdma: Add common XDR decoders for RDMA and Read segments
SUNRPC: Add helpers for decoding list discriminators symbolically
svcrdma: Remove declarations for functions long removed
svcrdma: Clean up trace_svcrdma_send_failed() tracepoint
...
-----BEGIN PGP SIGNATURE-----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=7CeF
-----END PGP SIGNATURE-----
Merge tag 'filelock-v5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux
Pull file locking fix from Jeff Layton:
"Just a single, one-line patch to fix an inefficiency in the posix
locking code that can lead to it doing more wakeups than necessary"
* tag 'filelock-v5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
locks: add locks_move_blocks in posix_lock_inode
We recently fixed lease breaking so that a client's actions won't break
its own delegations.
But we still have an unnecessary self-conflict when granting
delegations: a client's own write opens will prevent us from handing out
a read delegation even when no other client has the file open for write.
Fix that by turning off the checks for conflicting opens under
vfs_setlease, and instead performing those checks in the nfsd code.
We don't depend much on locks here: instead we acquire the delegation,
then check for conflicts, and drop the delegation again if we find any.
The check beforehand is an optimization of sorts, just to avoid
acquiring the delegation unnecessarily. There's a race where the first
check could cause us to deny the delegation when we could have granted
it. But, that's OK, delegation grants are optional (and probably not
even a good idea in that case).
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
- Keep nfsd clients from unnecessarily breaking their own delegations:
Note this requires a small kthreadd addition, discussed at:
https://lore.kernel.org/r/1588348912-24781-1-git-send-email-bfields@redhat.com
The result is Tejun Heo's suggestion, and he was OK with this going
through my tree.
- Patch nfsd/clients/ to display filenames, and to fix byte-order when
displaying stateid's.
- fix a module loading/unloading bug, from Neil Brown.
- A big series from Chuck Lever with RPC/RDMA and tracing improvements,
and lay some groundwork for RPC-over-TLS.
Note Stephen Rothwell spotted two conflicts in linux-next. Both should
be straightforward:
include/trace/events/sunrpc.h
https://lore.kernel.org/r/20200529105917.50dfc40f@canb.auug.org.au
net/sunrpc/svcsock.c
https://lore.kernel.org/r/20200529131955.26c421db@canb.auug.org.au
-----BEGIN PGP SIGNATURE-----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=YEf0
-----END PGP SIGNATURE-----
Merge tag 'nfsd-5.8' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"Highlights:
- Keep nfsd clients from unnecessarily breaking their own
delegations.
Note this requires a small kthreadd addition. The result is Tejun
Heo's suggestion (see link), and he was OK with this going through
my tree.
- Patch nfsd/clients/ to display filenames, and to fix byte-order
when displaying stateid's.
- fix a module loading/unloading bug, from Neil Brown.
- A big series from Chuck Lever with RPC/RDMA and tracing
improvements, and lay some groundwork for RPC-over-TLS"
Link: https://lore.kernel.org/r/1588348912-24781-1-git-send-email-bfields@redhat.com
* tag 'nfsd-5.8' of git://linux-nfs.org/~bfields/linux: (49 commits)
sunrpc: use kmemdup_nul() in gssp_stringify()
nfsd: safer handling of corrupted c_type
nfsd4: make drc_slab global, not per-net
SUNRPC: Remove unreachable error condition in rpcb_getport_async()
nfsd: Fix svc_xprt refcnt leak when setup callback client failed
sunrpc: clean up properly in gss_mech_unregister()
sunrpc: svcauth_gss_register_pseudoflavor must reject duplicate registrations.
sunrpc: check that domain table is empty at module unload.
NFSD: Fix improperly-formatted Doxygen comments
NFSD: Squash an annoying compiler warning
SUNRPC: Clean up request deferral tracepoints
NFSD: Add tracepoints for monitoring NFSD callbacks
NFSD: Add tracepoints to the NFSD state management code
NFSD: Add tracepoints to NFSD's duplicate reply cache
SUNRPC: svc_show_status() macro should have enum definitions
SUNRPC: Restructure svc_udp_recvfrom()
SUNRPC: Refactor svc_recvfrom()
SUNRPC: Clean up svc_release_skb() functions
SUNRPC: Refactor recvfrom path dealing with incomplete TCP receives
SUNRPC: Replace dprintk() call sites in TCP receive path
...
Pull proc updates from Eric Biederman:
"This has four sets of changes:
- modernize proc to support multiple private instances
- ensure we see the exit of each process tid exactly
- remove has_group_leader_pid
- use pids not tasks in posix-cpu-timers lookup
Alexey updated proc so each mount of proc uses a new superblock. This
allows people to actually use mount options with proc with no fear of
messing up another mount of proc. Given the kernel's internal mounts
of proc for things like uml this was a real problem, and resulted in
Android's hidepid mount options being ignored and introducing security
issues.
The rest of the changes are small cleanups and fixes that came out of
my work to allow this change to proc. In essence it is swapping the
pids in de_thread during exec which removes a special case the code
had to handle. Then updating the code to stop handling that special
case"
* 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
proc: proc_pid_ns takes super_block as an argument
remove the no longer needed pid_alive() check in __task_pid_nr_ns()
posix-cpu-timers: Replace __get_task_for_clock with pid_for_clock
posix-cpu-timers: Replace cpu_timer_pid_type with clock_pid_type
posix-cpu-timers: Extend rcu_read_lock removing task_struct references
signal: Remove has_group_leader_pid
exec: Remove BUG_ON(has_group_leader_pid)
posix-cpu-timer: Unify the now redundant code in lookup_task
posix-cpu-timer: Tidy up group_leader logic in lookup_task
proc: Ensure we see the exit of each process tid exactly once
rculist: Add hlists_swap_heads_rcu
proc: Use PIDTYPE_TGID in next_tgid
Use proc_pid_ns() to get pid_namespace from the proc superblock
proc: use named enums for better readability
proc: use human-readable values for hidepid
docs: proc: add documentation for "hidepid=4" and "subset=pid" options and new mount behavior
proc: add option to mount only a pids subset
proc: instantiate only pids that we can ptrace on 'hidepid=4' mount option
proc: allow to mount many instances of proc in one pid namespace
proc: rename struct proc_fs_info to proc_fs_opts
We forget to call locks_move_blocks in posix_lock_inode when try to
process same owner and different types.
Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
syzbot found that
touch /proc/testfile
causes NULL pointer dereference at tomoyo_get_local_path()
because inode of the dentry is NULL.
Before c59f415a7c, Tomoyo received pid_ns from proc's s_fs_info
directly. Since proc_pid_ns() can only work with inode, using it in
the tomoyo_get_local_path() was wrong.
To avoid creating more functions for getting proc_ns, change the
argument type of the proc_pid_ns() function. Then, Tomoyo can use
the existing super_block to get pid_ns.
Link: https://lkml.kernel.org/r/0000000000002f0c7505a5b0e04c@google.com
Link: https://lkml.kernel.org/r/20200518180738.2939611-1-gladkov.alexey@gmail.com
Reported-by: syzbot+c1af344512918c61362c@syzkaller.appspotmail.com
Fixes: c59f415a7c ("Use proc_pid_ns() to get pid_namespace from the proc superblock")
Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
We currently revoke read delegations on any write open or any operation
that modifies file data or metadata (including rename, link, and
unlink). But if the delegation in question is the only read delegation
and is held by the client performing the operation, that's not really
necessary.
It's not always possible to prevent this in the NFSv4.0 case, because
there's not always a way to determine which client an NFSv4.0 delegation
came from. (In theory we could try to guess this from the transport
layer, e.g., by assuming all traffic on a given TCP connection comes
from the same client. But that's not really correct.)
In the NFSv4.1 case the session layer always tells us the client.
This patch should remove such self-conflicts in all cases where we can
reliably determine the client from the compound.
To do that we need to track "who" is performing a given (possibly
lease-breaking) file operation. We're doing that by storing the
information in the svc_rqst and using kthread_data() to map the current
task back to a svc_rqst.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There is measurable performance impact in some synthetic tests due to
commit 6d390e4b5d (locks: fix a potential use-after-free problem when
wakeup a waiter). Fix the race condition instead by clearing the
fl_blocker pointer after the wake_up, using explicit acquire/release
semantics.
This does mean that we can no longer use the clearing of fl_blocker as
the wait condition, so switch the waiters over to checking whether the
fl_blocked_member list_head is empty.
Reviewed-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Fixes: 6d390e4b5d (locks: fix a potential use-after-free problem when wakeup a waiter)
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'16306a61d3b7 ("fs/locks: always delete_block after waiting.")' add the
logic to check waiter->fl_blocker without blocked_lock_lock. And it will
trigger a UAF when we try to wakeup some waiter：
Thread 1 has create a write flock a on file, and now thread 2 try to
unlock and delete flock a, thread 3 try to add flock b on the same file.
Thread2 Thread3
flock syscall(create flock b)
...flock_lock_inode_wait
flock_lock_inode(will insert
our fl_blocked_member list
to flock a's fl_blocked_requests)
sleep
flock syscall(unlock)
...flock_lock_inode_wait
locks_delete_lock_ctx
...__locks_wake_up_blocks
__locks_delete_blocks(
b->fl_blocker = NULL)
...
break by a signal
locks_delete_block
b->fl_blocker == NULL &&
list_empty(&b->fl_blocked_requests)
success, return directly
locks_free_lock b
wake_up(&b->fl_waiter)
trigger UAF
Fix it by remove this logic, and this patch may also fix CVE-2019-19769.
Cc: stable@vger.kernel.org
Fixes: 16306a61d3 ("fs/locks: always delete_block after waiting.")
Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
An ino is unsigned, so display it as such in /proc/locks.
Cc: stable@vger.kernel.org
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
- add a new knfsd file cache, so that we don't have to open and
close on each (NFSv2/v3) READ or WRITE. This can speed up
read and write in some cases. It also replaces our readahead
cache.
- Prevent silent data loss on write errors, by treating write
errors like server reboots for the purposes of write caching,
thus forcing clients to resend their writes.
- Tweak the code that allocates sessions to be more forgiving,
so that NFSv4.1 mounts are less likely to hang when a server
already has a lot of clients.
- Eliminate an arbitrary limit on NFSv4 ACL sizes; they should
now be limited only by the backend filesystem and the
maximum RPC size.
- Allow the server to enforce use of the correct kerberos
credentials when a client reclaims state after a reboot.
And some miscellaneous smaller bugfixes and cleanup.
-----BEGIN PGP SIGNATURE-----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=diBo
-----END PGP SIGNATURE-----
Merge tag 'nfsd-5.4' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"Highlights:
- Add a new knfsd file cache, so that we don't have to open and close
on each (NFSv2/v3) READ or WRITE. This can speed up read and write
in some cases. It also replaces our readahead cache.
- Prevent silent data loss on write errors, by treating write errors
like server reboots for the purposes of write caching, thus forcing
clients to resend their writes.
- Tweak the code that allocates sessions to be more forgiving, so
that NFSv4.1 mounts are less likely to hang when a server already
has a lot of clients.
- Eliminate an arbitrary limit on NFSv4 ACL sizes; they should now be
limited only by the backend filesystem and the maximum RPC size.
- Allow the server to enforce use of the correct kerberos credentials
when a client reclaims state after a reboot.
And some miscellaneous smaller bugfixes and cleanup"
* tag 'nfsd-5.4' of git://linux-nfs.org/~bfields/linux: (34 commits)
sunrpc: clean up indentation issue
nfsd: fix nfs read eof detection
nfsd: Make nfsd_reset_boot_verifier_locked static
nfsd: degraded slot-count more gracefully as allocation nears exhaustion.
nfsd: handle drc over-allocation gracefully.
nfsd: add support for upcall version 2
nfsd: add a "GetVersion" upcall for nfsdcld
nfsd: Reset the boot verifier on all write I/O errors
nfsd: Don't garbage collect files that might contain write errors
nfsd: Support the server resetting the boot verifier
nfsd: nfsd_file cache entries should be per net namespace
nfsd: eliminate an unnecessary acl size limit
Deprecate nfsd fault injection
nfsd: remove duplicated include from filecache.c
nfsd: Fix the documentation for svcxdr_tmpalloc()
nfsd: Fix up some unused variable warnings
nfsd: close cached files prior to a REMOVE or RENAME that would replace target
nfsd: rip out the raparms cache
nfsd: have nfsd_test_lock use the nfsd_file cache
nfsd: hook up nfs4_preprocess_stateid_op to the nfsd_file cache
...
In __break_lease(), the file lock 'new_fl' is allocated in lease_alloc().
However, it is not deallocated in the following execution if
smp_load_acquire() fails, leading to a memory leak bug. To fix this issue,
free 'new_fl' before returning the error.
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Have them keep an nfsd_file reference instead of a struct file.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
With the new file caching infrastructure in nfsd, we can end up holding
files open for an indefinite period of time, even when they are still
idle. This may prevent the kernel from handing out leases on the file,
which is something we don't want to block.
Fix this by running a SRCU notifier call chain whenever on any
lease attempt. nfsd can then purge the cache for that inode before
returning.
Since SRCU is only conditionally compiled in, we must only define the
new chain if it's enabled, and users of the chain must ensure that
SRCU is enabled.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Since commit 778fc546f7 ("locks: fix tracking of inprogress
lease breaks"), leases break don't change @fl_type but modifies
@fl_flags. However, procfs's part haven't been updated.
Previously, for a breaking lease the target type was printed (see
target_leasetype()), as returns fcntl(F_GETLEASE). But now it's always
"READ", as F_UNLCK no longer means "breaking". Unlike the previous
one, this behaviour don't provide a complete description of the lease.
There are /proc/pid/fdinfo/ outputs for a lease (the same for READ and
WRITE) breaked by O_WRONLY.
-- before:
lock: 1: LEASE BREAKING READ 2558 08:03:815793 0 EOF
-- after:
lock: 1: LEASE BREAKING UNLCK 2558 08:03:815793 0 EOF
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
- Add a new /proc/fs/nfsd/clients/ directory which exposes some
long-requested information about NFSv4 clients (like open files) and
allows forced revocation of client state.
- Replace the global duplicate reply cache by a cache per network
namespace; previously, a request in one network namespace could
incorrectly match an entry from another, though we haven't seen this
in production. This is the last remaining container bug that I'm
aware of; at this point you should be able to run separate nfsd's in
each network namespace, each with their own set of exports, and
everything should work.
- Cleanup and modify lock code to show the pid of lockd as the owner of
NLM locks. This is the correct version of the bugfix originally
attempted in b8eee0e90f "lockd: Show pid of lockd for remote locks".
-----BEGIN PGP SIGNATURE-----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=pAAs
-----END PGP SIGNATURE-----
Merge tag 'nfsd-5.3' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"Highlights:
- Add a new /proc/fs/nfsd/clients/ directory which exposes some
long-requested information about NFSv4 clients (like open files)
and allows forced revocation of client state.
- Replace the global duplicate reply cache by a cache per network
namespace; previously, a request in one network namespace could
incorrectly match an entry from another, though we haven't seen
this in production. This is the last remaining container bug that
I'm aware of; at this point you should be able to run separate
nfsd's in each network namespace, each with their own set of
exports, and everything should work.
- Cleanup and modify lock code to show the pid of lockd as the owner
of NLM locks. This is the correct version of the bugfix originally
attempted in b8eee0e90f ("lockd: Show pid of lockd for remote
locks")"
* tag 'nfsd-5.3' of git://linux-nfs.org/~bfields/linux: (34 commits)
nfsd: Make __get_nfsdfs_client() static
nfsd: Make two functions static
nfsd: Fix misuse of strlcpy
sunrpc/cache: remove the exporting of cache_seq_next
nfsd: decode implementation id
nfsd: create xdr_netobj_dup helper
nfsd: allow forced expiration of NFSv4 clients
nfsd: create get_nfsdfs_clp helper
nfsd4: show layout stateids
nfsd: show lock and deleg stateids
nfsd4: add file to display list of client's opens
nfsd: add more information to client info file
nfsd: escape high characters in binary data
nfsd: copy client's address including port number to cl_addr
nfsd4: add a client info file
nfsd: make client/ directory names small ints
nfsd: add nfsd/clients directory
nfsd4: use reference count to free client
nfsd: rename cl_refcount
nfsd: persist nfsd filesystem across mounts
...
After the update to use nlm_lockowners for the NLM server, there are no
more users of lm_compare_owner and lm_owner_key.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
check_conflicting_open() is checking for existing fd's open for read or
for write before allowing to take a write lease. The check that was
implemented using i_count and d_count is an approximation that has
several false positives. For example, overlayfs since v4.19, takes an
extra reference on the dentry; An open with O_PATH takes a reference on
the dentry although the file cannot be read nor written.
Change the implementation to use i_readcount and i_writecount to
eliminate the false positive conflicts and allow a write lease to be
taken on an overlayfs file.
The change of behavior with existing fd's open with O_PATH is symmetric
w.r.t. current behavior of lease breakers - an open with O_PATH currently
does not break a write lease.
This increases the size of struct inode by 4 bytes on 32bit archs when
CONFIG_FILE_LOCKING is defined and CONFIG_IMA was not already
defined.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Scott Mayhew revived an old api that communicates with a userspace
daemon to manage some on-disk state that's used to track clients across
server reboots. We've been using a usermode_helper upcall for that, but
it's tough to run those with the right namespaces, so a daemon is much
friendlier to container use cases.
Trond fixed nfsd's handling of user credentials in user namespaces. He
also contributed patches that allow containers to support different sets
of NFS protocol versions.
The only remaining container bug I'm aware of is that the NFS reply
cache is shared between all containers. If anyone's aware of other gaps
in our container support, let me know.
The rest of this is miscellaneous bugfixes.
-----BEGIN PGP SIGNATURE-----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=TUdw
-----END PGP SIGNATURE-----
Merge tag 'nfsd-5.2' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"This consists mostly of nfsd container work:
Scott Mayhew revived an old api that communicates with a userspace
daemon to manage some on-disk state that's used to track clients
across server reboots. We've been using a usermode_helper upcall for
that, but it's tough to run those with the right namespaces, so a
daemon is much friendlier to container use cases.
Trond fixed nfsd's handling of user credentials in user namespaces. He
also contributed patches that allow containers to support different
sets of NFS protocol versions.
The only remaining container bug I'm aware of is that the NFS reply
cache is shared between all containers. If anyone's aware of other
gaps in our container support, let me know.
The rest of this is miscellaneous bugfixes"
* tag 'nfsd-5.2' of git://linux-nfs.org/~bfields/linux: (23 commits)
nfsd: update callback done processing
locks: move checks from locks_free_lock() to locks_release_private()
nfsd: fh_drop_write in nfsd_unlink
nfsd: allow fh_want_write to be called twice
nfsd: knfsd must use the container user namespace
SUNRPC: rsi_parse() should use the current user namespace
SUNRPC: Fix the server AUTH_UNIX userspace mappings
lockd: Pass the user cred from knfsd when starting the lockd server
SUNRPC: Temporary sockets should inherit the cred from their parent
SUNRPC: Cache the process user cred in the RPC server listener
nfsd: Allow containers to set supported nfs versions
nfsd: Add custom rpcbind callbacks for knfsd
SUNRPC: Allow further customisation of RPC program registration
SUNRPC: Clean up generic dispatcher code
SUNRPC: Add a callback to initialise server requests
SUNRPC/nfs: Fix return value for nfs4_callback_compound()
nfsd: handle legacy client tracking records sent by nfsdcld
nfsd: re-order client tracking method selection
nfsd: keep a tally of RECLAIM_COMPLETE operations when using nfsdcld
nfsd: un-deprecate nfsdcld
...
Hi Linus,
This is my very first pull-request. I've been working full-time as
a kernel developer for more than two years now. During this time I've
been fixing bugs reported by Coverity all over the tree and, as part
of my work, I'm also contributing to the KSPP. My work in the kernel
community has been supervised by Greg KH and Kees Cook.
OK. So, after the quick introduction above, please, pull the following
patches that mark switch cases where we are expecting to fall through.
These patches are part of the ongoing efforts to enable -Wimplicit-fallthrough.
They have been ignored for a long time (most of them more than 3 months,
even after pinging multiple times), which is the reason why I've created
this tree. Most of them have been baking in linux-next for a whole development
cycle. And with Stephen Rothwell's help, we've had linux-next nag-emails
going out for newly introduced code that triggers -Wimplicit-fallthrough
to avoid gaining more of these cases while we work to remove the ones
that are already present.
I'm happy to let you know that we are getting close to completing this
work. Currently, there are only 32 of 2311 of these cases left to be
addressed in linux-next. I'm auditing every case; I take a look into
the code and analyze it in order to determine if I'm dealing with an
actual bug or a false positive, as explained here:
https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
While working on this, I've found and fixed the following missing
break/return bugs, some of them introduced more than 5 years ago:
84242b82d87850b51b6c5e420fe63509186e5034b5be8531817264235ee7cc5034a5d2479826cc865340f23df8df997abeeb2f10d82373307b00c5e65d25ff7a54a7ed5b3e7dc24bfa8f21ad0eaee6199ba8376ce1dc586a60a1a8e9b186f14e57562b4860747828eac5b974bee9cc44ba91162c930e3d0a
Once this work is finish, we'll be able to universally enable
"-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
entering the kernel again.
Thanks
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
-----BEGIN PGP SIGNATURE-----
iQIzBAABCAAdFiEEkmRahXBSurMIg1YvRwW0y0cG2zEFAlzQR2IACgkQRwW0y0cG
2zEJbQ//X930OcBtT/9DRW4XL1Jeq0Mjssz/GLX2Vpup5CwwcTROG65no80Zezf/
yQRWnUjGX0OBv/fmUK32/nTxI/7k7NkmIXJHe0HiEF069GEENB7FT6tfDzIPjU8M
qQkB8NsSUWJs3IH6BVynb/9MGE1VpGBDbYk7CBZRtRJT1RMM+3kQPucgiZMgUBPo
Yd9zKwn4i/8tcOCli++EUdQ29ukMoY2R3qpK4LftdX9sXLKZBWNwQbiCwSkjnvJK
I6FDiA7RaWH2wWGlL7BpN5RrvAXp3z8QN/JZnivIGt4ijtAyxFUL/9KOEgQpBQN2
6TBRhfTQFM73NCyzLgGLNzvd8awem1rKGSBBUvevaPbgesgM+Of65wmmTQRhFNCt
A7+e286X1GiK3aNcjUKrByKWm7x590EWmDzmpmICxNPdt5DHQ6EkmvBdNjnxCMrO
aGA24l78tBN09qN45LR7wtHYuuyR0Jt9bCmeQZmz7+x3ICDHi/+Gw7XPN/eM9+T6
lZbbINiYUyZVxOqwzkYDCsdv9+kUvu3e4rPs20NERWRpV8FEvBIyMjXAg6NAMTue
K+ikkyMBxCvyw+NMimHJwtD7ho4FkLPcoeXb2ZGJTRHixiZAEtF1RaQ7dA05Q/SL
gbSc0DgLZeHlLBT+BSWC2Z8SDnoIhQFXW49OmuACwCUC68NHKps=
=k30z
-----END PGP SIGNATURE-----
Merge tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull Wimplicit-fallthrough updates from Gustavo A. R. Silva:
"Mark switch cases where we are expecting to fall through.
This is part of the ongoing efforts to enable -Wimplicit-fallthrough.
Most of them have been baking in linux-next for a whole development
cycle. And with Stephen Rothwell's help, we've had linux-next
nag-emails going out for newly introduced code that triggers
-Wimplicit-fallthrough to avoid gaining more of these cases while we
work to remove the ones that are already present.
We are getting close to completing this work. Currently, there are
only 32 of 2311 of these cases left to be addressed in linux-next. I'm
auditing every case; I take a look into the code and analyze it in
order to determine if I'm dealing with an actual bug or a false
positive, as explained here:
https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
While working on this, I've found and fixed the several missing
break/return bugs, some of them introduced more than 5 years ago.
Once this work is finished, we'll be able to universally enable
"-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
entering the kernel again"
* tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (27 commits)
memstick: mark expected switch fall-throughs
drm/nouveau/nvkm: mark expected switch fall-throughs
NFC: st21nfca: Fix fall-through warnings
NFC: pn533: mark expected switch fall-throughs
block: Mark expected switch fall-throughs
ASN.1: mark expected switch fall-through
lib/cmdline.c: mark expected switch fall-throughs
lib: zstd: Mark expected switch fall-throughs
scsi: sym53c8xx_2: sym_nvram: Mark expected switch fall-through
scsi: sym53c8xx_2: sym_hipd: mark expected switch fall-throughs
scsi: ppa: mark expected switch fall-through
scsi: osst: mark expected switch fall-throughs
scsi: lpfc: lpfc_scsi: Mark expected switch fall-throughs
scsi: lpfc: lpfc_nvme: Mark expected switch fall-through
scsi: lpfc: lpfc_nportdisc: Mark expected switch fall-through
scsi: lpfc: lpfc_hbadisc: Mark expected switch fall-throughs
scsi: lpfc: lpfc_els: Mark expected switch fall-throughs
scsi: lpfc: lpfc_ct: Mark expected switch fall-throughs
scsi: imm: mark expected switch fall-throughs
scsi: csiostor: csio_wr: mark expected switch fall-through
...
Code that allocates locks using locks_alloc_lock() will free it
using locks_free_lock(), and will benefit from the BUG_ON()
consistency checks therein.
However some code (nfsd and lockd) allocate a lock embedded in
some other data structure, and so free the lock themselves after
calling locks_release_private(). This path does not benefit from
the consistency checks.
To help catch future errors, move the BUG_ON() checks to
locks_release_private() - which locks_free_lock() already calls.
This ensures that all users for locks will find out if the lock
isn't detached properly before being free.
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
This patch fixes the following warnings:
fs/affs/affs.h:124:38: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/configfs/dir.c:1692:11: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/configfs/dir.c:1694:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ceph/file.c:249:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/hash.c:233:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/hash.c:246:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext2/inode.c:1237:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext2/inode.c:1244:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/indirect.c:1182:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/indirect.c:1188:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/indirect.c:1432:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/indirect.c:1440:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/f2fs/node.c:618:8: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/f2fs/node.c:620:8: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/btrfs/ref-verify.c:522:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/gfs2/bmap.c:711:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/gfs2/bmap.c:722:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/jffs2/fs.c:339:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/nfsd/nfs4proc.c:429:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ufs/util.h:62:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ufs/util.h:43:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/fcntl.c:770:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/seq_file.c:319:10: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/libfs.c:148:11: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/libfs.c:150:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/signalfd.c:178:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/locks.c:1473:16: warning: this statement may fall through [-Wimplicit-fallthrough=]
Warning level 3 was used: -Wimplicit-fallthrough=3
This patch is part of the ongoing efforts to enabling
-Wimplicit-fallthrough.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Andreas reported that he was seeing the tdbtorture test fail in some
cases with -EDEADLCK when it wasn't before. Some debugging showed that
deadlock detection was sometimes discovering the caller's lock request
itself in a dependency chain.
While we remove the request from the blocked_lock_hash prior to
reattempting to acquire it, any locks that are blocked on that request
will still be present in the hash and will still have their fl_blocker
pointer set to the current request.
This causes posix_locks_deadlock to find a deadlock dependency chain
when it shouldn't, as a lock request cannot block itself.
We are going to end up waking all of those blocked locks anyway when we
go to reinsert the request back into the blocked_lock_hash, so just do
it prior to checking for deadlocks. This ensures that any lock blocked
on the current request will no longer be part of any blocked request
chain.
URL: https://bugzilla.kernel.org/show_bug.cgi?id=202975
Fixes: 5946c4319e ("fs/locks: allow a lock request to block other requests.")
Cc: stable@vger.kernel.org
Reported-by: Andreas Schneider <asn@redhat.com>
Signed-off-by: Neil Brown <neilb@suse.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Effective revert commit:
87709e28dc ("fs/locks: Use percpu_down_read_preempt_disable()")
This is causing major pain for PREEMPT_RT.
Sebastian did a lot of lockperf runs on 2 and 4 node machines with all
preemption modes (PREEMPT=n should be an obvious NOP for this patch
and thus serves as a good control) and no results showed significance
over 2-sigma (the PREEMPT=n results were almost empty at 1-sigma).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
After moving all requests from
fl->fl_blocked_requests
to
new->fl_blocked_requests
it is nonsensical to do anything to all the remaining elements, there
aren't any. This should do something to all the requests that have been
moved. For simplicity, it does it to all requests in the target list.
Setting "f->fl_blocker = new" to all members of new->fl_blocked_requests
is "obviously correct" as it preserves the invariant of the linkage
among requests.
Reported-by: syzbot+239d99847eb49ecb3899@syzkaller.appspotmail.com
Fixes: 5946c4319e ("fs/locks: allow a lock request to block other requests.")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Use the aptly named function rather than open coding it. No functional
changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
- spaces before tabs,
- spaces at the end of lines,
- multiple blank lines,
- blank lines before EXPORT_SYMBOL,
can all go.
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
posix_unblock_lock() is not specific to posix locks, and behaves
nearly identically to locks_delete_block() - the former returning a
status while the later doesn't.
So discard posix_unblock_lock() and use locks_delete_block() instead,
after giving that function an appropriate return value.
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
When we find an existing lock which conflicts with a request,
and the request wants to wait, we currently add the request
to a list. When the lock is removed, the whole list is woken.
This can cause the thundering-herd problem.
To reduce the problem, we make use of the (new) fact that
a pending request can itself have a list of blocked requests.
When we find a conflict, we look through the existing blocked requests.
If any one of them blocks the new request, the new request is attached
below that request, otherwise it is added to the list of blocked
requests, which are now known to be mutually non-conflicting.
This way, when the lock is released, only a set of non-conflicting
locks will be woken, the rest can stay asleep.
If the lock request cannot be granted and the request needs to be
requeued, all the other requests it blocks will then be woken
To make this more concrete:
If you have a many-core machine, and have many threads all wanting to
briefly lock a give file (udev is known to do this), you can get quite
poor performance.
When one thread releases a lock, it wakes up all other threads that
are waiting (classic thundering-herd) - one will get the lock and the
others go to sleep.
When you have few cores, this is not very noticeable: by the time the
4th or 5th thread gets enough CPU time to try to claim the lock, the
earlier threads have claimed it, done what was needed, and released.
So with few cores, many of the threads don't end up contending.
With 50+ cores, lost of threads can get the CPU at the same time,
and the contention can easily be measured.
This patchset creates a tree of pending lock requests in which siblings
don't conflict and each lock request does conflict with its parent.
When a lock is released, only requests which don't conflict with each
other a woken.
Testing shows that lock-acquisitions-per-second is now fairly stable
even as the number of contending process goes to 1000. Without this
patch, locks-per-second drops off steeply after a few 10s of
processes.
There is a small cost to this extra complexity.
At 20 processes running a particular test on 72 cores, the lock
acquisitions per second drops from 1.8 million to 1.4 million with
this patch. For 100 processes, this patch still provides 1.4 million
while without this patch there are about 700,000.
Reported-and-tested-by: Martin Wilck <mwilck@suse.de>
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
posix_locks_conflict() and flock_locks_conflict() both return int.
leases_conflict() returns bool.
This inconsistency will cause problems for the next patch if not
fixed.
So change posix_locks_conflict() and flock_locks_conflict() to return
bool.
Also change the locks_conflict() helper.
And convert some
return (foo);
to
return foo;
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Now that requests can block other requests, we
need to be careful to always clean up those blocked
requests.
Any time that we wait for a request, we might have
other requests attached, and when we stop waiting,
we must clean them up.
If the lock was granted, the requests might have been
moved to the new lock, though when merged with a
pre-exiting lock, this might not happen.
In all cases we don't want blocked locks to remain
attached, so we remove them to be safe.
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Tested-by: syzbot+a4a3d526b4157113ec6a@syzkaller.appspotmail.com
Tested-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Currently, a lock can block pending requests, but all pending
requests are equal. If lots of pending requests are
mutually exclusive, this means they will all be woken up
and all but one will fail. This can hurt performance.
So we will allow pending requests to block other requests.
Only the first request will be woken, and it will wake the others.
This patch doesn't implement this fully, but prepares the way.
- It acknowledges that a request might be blocking other requests,
and when the request is converted to a lock, those blocked
requests are moved across.
- When a request is requeued or discarded, all blocked requests are
woken.
- When deadlock-detection looks for the lock which blocks a
given request, we follow the chain of ->fl_blocker all
the way to the top.
Tested-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Both locks_remove_posix() and locks_remove_flock() use a
struct file_lock without calling locks_init_lock() on it.
This means the various list_heads are not initialized, which
will become a problem with a later patch.
So change them both to initialize properly. For flock locks,
this involves using flock_make_lock(), and changing it to
allow a file_lock to be passed in, so memory allocation isn't
always needed.
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
