summaryrefslogtreecommitdiffstats
path: root/fs/locks.c
Commit message (Collapse)AuthorAgeFilesLines
* Merge tag 'nfsd-5.13-1' of ↵Linus Torvalds2021-05-051-0/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * nfsd: grant read delegations to clients holding writesJ. Bruce Fields2021-04-191-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 94415b06eb8a ("nfsd4: a client's own opens needn't prevent delegations"), which had to be reverted in commit 6ee65a773096 ("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>
* | Merge tag 'locks-v5.13' of ↵Linus Torvalds2021-04-261-10/+56
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * fs/locks: remove useless assignment in fcntl_getlkTian Tao2021-04-131-1/+0
| | | | | | | | | | | | | | 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>
| * fs/locks: print full locks informationLuo Longjun2021-03-111-9/+56
| | | | | | | | | | | | | | | | | | | | | | | | Commit fd7732e033e3 ("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>
* | Revert "nfsd4: a client's own opens needn't prevent delegations"J. Bruce Fields2021-03-091-3/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 94415b06eb8aed13481646026dc995f04a3a534a. 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>
* Merge branch 'exec-for-v5.11' of ↵Linus Torvalds2020-12-151-6/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 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 ...
| * file: Factor files_lookup_fd_locked out of fcheck_filesEric W. Biederman2020-12-101-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | locks: fix a typo at a kernel-doc markupMauro Carvalho Chehab2020-10-261-1/+1
| | | | | | | | | | | | | | locks_delete_lock -> locks_delete_block Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Jeff Layton <jlayton@kernel.org>
* | locks: Fix UBSAN undefined behaviour in flock64_to_posix_lockLuo Meng2020-10-261-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva2020-08-231-3/+3
| | | | | | | | | | Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* Merge tag 'nfsd-5.9' of git://git.linux-nfs.org/projects/cel/cel-2.6Linus Torvalds2020-08-091-0/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * nfsd4: a client's own opens needn't prevent delegationsJ. Bruce Fields2020-07-131-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge tag 'filelock-v5.9-1' of ↵Linus Torvalds2020-08-031-0/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | 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
| * locks: add locks_move_blocks in posix_lock_inodeyangerkun2020-06-021-0/+1
| | | | | | | | | | | | | | | | 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>
* | Merge tag 'nfsd-5.8' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2020-06-111-0/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * | nfsd: clients don't need to break their own delegationsJ. Bruce Fields2020-05-081-0/+3
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge branch 'proc-linus' of ↵Linus Torvalds2020-06-041-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 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
| * | proc: proc_pid_ns takes super_block as an argumentAlexey Gladkov2020-05-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot found that touch /proc/testfile causes NULL pointer dereference at tomoyo_get_local_path() because inode of the dentry is NULL. Before c59f415a7cb6, 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: c59f415a7cb6 ("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>
| * | Use proc_pid_ns() to get pid_namespace from the proc superblockAlexey Gladkov2020-04-241-2/+2
| |/ | | | | | | | | | | | | | | | | | | | | To get pid_namespace from the procfs superblock should be used a special helper. This will avoid errors when s_fs_info will change the type. Link: https://lore.kernel.org/lkml/20200423200316.164518-3-gladkov.alexey@gmail.com/ Link: https://lore.kernel.org/lkml/20200423112858.95820-1-gladkov.alexey@gmail.com/ Link: https://lore.kernel.org/lkml/06B50A1C-406F-4057-BFA8-3A7729EA7469@lca.pw/ Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* / docs: filesystems: convert mandatory-locking.txt to ReSTMauro Carvalho Chehab2020-05-051-1/+1
|/ | | | | | | | | | | | - Add a SPDX header; - Adjust document title; - Some whitespace fixes and new line breaks; - Use notes markups; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/aecd6259fe9f99b2c2b3440eab6a2b989125e00d.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* locks: reinstate locks_delete_block optimizationLinus Torvalds2020-03-181-6/+48
| | | | | | | | | | | | | | | | | | There is measurable performance impact in some synthetic tests due to commit 6d390e4b5d48 (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: 6d390e4b5d48 (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>
* locks: fix a potential use-after-free problem when wakeup a waiteryangerkun2020-03-061-14/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | '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: 16306a61d3b7 ("fs/locks: always delete_block after waiting.") Signed-off-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Jeff Layton <jlayton@kernel.org>
* locks: print unsigned ino in /proc/locksAmir Goldstein2019-12-291-1/+1
| | | | | | | | 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>
* Merge tag 'nfsd-5.4' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2019-09-271-0/+62
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * nfsd: convert fi_deleg_file and ls_file fields to nfsd_fileJeff Layton2019-08-191-0/+1
| | | | | | | | | | | | | | | | | | 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>
| * locks: create a new notifier chain for lease attemptsJeff Layton2019-08-191-0/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | locks: fix a memory leak bug in __break_lease()Wenwen Wang2019-08-201-1/+2
| | | | | | | | | | | | | | | | | | | | 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>
* | locks: Fix procfs output for file leasesPavel Begunkov2019-07-251-4/+4
|/ | | | | | | | | | | | | | | | | | | | | Since commit 778fc546f749c588aa2f ("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>
* Merge tag 'nfsd-5.3' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2019-07-101-5/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 b8eee0e90f97 ("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 ...
| * locks: Cleanup lm_compare_owner and lm_owner_keyBenjamin Coddington2019-07-031-5/+0
| | | | | | | | | | | | | | | | 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>
* | locks: eliminate false positive conflicts for write leaseAmir Goldstein2019-06-191-15/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | locks: Add trace_leases_conflictIra Weiny2019-06-191-5/+15
|/ | | | | Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Jeff Layton <jlayton@kernel.org>
* treewide: Add SPDX license identifier for missed filesThomas Gleixner2019-05-211-0/+1
| | | | | | | | | | | | | | | | | 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>
* Merge tag 'nfsd-5.2' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2019-05-151-6/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * locks: move checks from locks_free_lock() to locks_release_private()NeilBrown2019-04-241-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge tag 'Wimplicit-fallthrough-5.2-rc1' of ↵Linus Torvalds2019-05-071-1/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * fs: mark expected switch fall-throughsGustavo A. R. Silva2019-04-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | locks: wake any locks blocked on request before deadlock checkJeff Layton2019-03-251-0/+5
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 5946c4319ebb ("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>
* locking/percpu-rwsem: Remove preempt_disable variantsPeter Zijlstra2019-02-281-16/+16
| | | | | | | | | | | | | | | | | | | | | | | | Effective revert commit: 87709e28dc7c ("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>
* locks: fix error in locks_move_blocks()NeilBrown2019-01-021-1/+1
| | | | | | | | | | | | | | | | | | | | 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: 5946c4319ebb ("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>
* locks: Use inode_is_open_for_writeNikolay Borisov2018-12-171-1/+1
| | | | | | | | 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>
* fs/locks: remove unnecessary white space.NeilBrown2018-12-071-21/+12
| | | | | | | | | | | | - 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>
* fs/locks: merge posix_unblock_lock() and locks_delete_block()NeilBrown2018-12-071-24/+14
| | | | | | | | | | | | | 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>
* fs/locks: create a tree of dependent requests.NeilBrown2018-12-071-6/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* fs/locks: change all *_conflict() functions to return bool.NeilBrown2018-12-071-12/+15
| | | | | | | | | | | | | | | | | | | | | 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>
* fs/locks: always delete_block after waiting.NeilBrown2018-12-071-16/+24
| | | | | | | | | | | | | | | | | | | | 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>
* fs/locks: allow a lock request to block other requests.NeilBrown2018-11-301-6/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* fs/locks: use properly initialized file_lock when unlocking.NeilBrown2018-11-301-14/+14
| | | | | | | | | | | | | | | | 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>
* fs/locks: split out __locks_wake_up_blocks().NeilBrown2018-11-301-11/+16
| | | | | | | | | This functionality will be useful in future patches, so split it out from locks_wake_up_blocks(). Signed-off-by: NeilBrown <neilb@suse.com> Reviewed-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Jeff Layton <jlayton@kernel.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 08:22:09 +0000