- 06 Feb, 2024 3 commits
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Oleg Nesterov authored
copy_process() just needs to pass PIDFD_THREAD to __pidfd_prepare() if clone_flags & CLONE_THREAD. We can also add another CLONE_ flag (or perhaps reuse CLONE_DETACHED) to enforce PIDFD_THREAD without CLONE_THREAD. Originally-from: Tycho Andersen <tycho@tycho.pizza> Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20240205145532.GA28823@redhat.comReviewed-by:
Tycho Andersen <tandersen@netflix.com> Signed-off-by:
Christian Brauner <brauner@kernel.org>
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Oleg Nesterov authored
It was used by pidfd_poll() but now it has no callers. If it finally finds a modular user we can revert this change, but note that the comment above this helper and the changelog in 38fd525a ("exit: Factor thread_group_exited out of pidfd_poll") are not accurate, thread_group_exited() won't return true if all other threads have passed exit_notify() and are zombies, it returns true only when all other threads are completely gone. Not to mention that it can only work if the task identified by @pid is a thread-group leader. Signed-off-by:
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Oleg Nesterov authored
rather than wake_up_all(). This way do_notify_pidfd() won't wakeup the POLLHUP-only waiters which wait for pid_task() == NULL. TODO: - as Christian pointed out, this asks for the new wake_up_all_poll() helper, it can already have other users. - we can probably discriminate the PIDFD_THREAD and non-PIDFD_THREAD waiters, but this needs more work. See https://lore.kernel.org/all/20240205140848.GA15853@redhat.com/Signed-off-by:
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- 02 Feb, 2024 7 commits
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Oleg Nesterov authored
transfer_pid() must be never called with pid == PIDTYPE_PID, new_leader->thread_pid should be changed by exchange_tids(). Signed-off-by:
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Oleg Nesterov authored
Now that __change_pid() does wake_up_all(&pid->wait_pidfd) we can kill do_notify_pidfd(leader) in de_thread(), it calls release_task(leader) right after that and this implies detach_pid(leader, PIDTYPE_PID). Signed-off-by:
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Oleg Nesterov authored
Add another wake_up_all(wait_pidfd) into __change_pid() and change pidfd_poll() to include EPOLLHUP if task == NULL. This allows to wait until the target process/thread is reaped. TODO: change do_notify_pidfd() to use the keyed wakeups. Signed-off-by:
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Oleg Nesterov authored
With this flag: - pidfd_open() doesn't require that the target task must be a thread-group leader - pidfd_poll() succeeds when the task exits and becomes a zombie (iow, passes exit_notify()), even if it is a leader and thread-group is not empty. This means that the behaviour of pidfd_poll(PIDFD_THREAD, pid-of-group-leader) is not well defined if it races with exec() from its sub-thread; pidfd_poll() can succeed or not depending on whether pidfd_task_exited() is called before or after exchange_tids(). Perhaps we can improve this behaviour later, pidfd_poll() can probably take sig->group_exec_task into account. But this doesn't really differ from the case when the leader exits before other threads (so pidfd_poll() succeeds) and then another thread execs and pidfd_poll() will block again. thread_group_exited() is no longer used, perhaps it can die. Co-developed-by:
Tycho Andersen <tycho@tycho.pizza> Signed-off-by:
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Oleg Nesterov authored
do_notify_pidfd() makes no sense until the whole thread group exits, change do_notify_parent() to check thread_group_empty(). This avoids the unnecessary do_notify_pidfd() when tsk is not a leader, or it exits before other threads, or it has a ptraced EXIT_ZOMBIE sub-thread. Signed-off-by:
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Oleg Nesterov authored
- make pidfd_create() static. - Don't pass O_RDWR | O_CLOEXEC to __pidfd_prepare() in copy_process(), __pidfd_prepare() adds these flags unconditionally. - Kill the flags check in __pidfd_prepare(). sys_pidfd_open() checks the flags itself, all other users of pidfd_prepare() pass flags = 0. If we need a sanity check for those other in kernel users then WARN_ON_ONCE(flags & ~PIDFD_NONBLOCK) makes more sense. - Don't pass O_RDWR to get_unused_fd_flags(), it ignores everything except O_CLOEXEC. - Don't pass O_CLOEXEC to anon_inode_getfile(), it ignores everything except O_ACCMODE | O_NONBLOCK. Signed-off-by:
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Wang Jinchao authored
In the current implementation of clone(), there is a line that initializes `u64 clone_flags = args->flags` at the top. This means that there is no longer a need to use args->flags for the legacy clone check. Signed-off-by:
Wang Jinchao <wangjinchao@xfusion.com> Link: https://lore.kernel.org/r/202401311054+0800-wangjinchao@xfusion.comSigned-off-by:
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- 21 Jan, 2024 30 commits
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Linus Torvalds authored
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https://evilpiepirate.org/git/bcachefsLinus Torvalds authored
Pull more bcachefs updates from Kent Overstreet: "Some fixes, Some refactoring, some minor features: - Assorted prep work for disk space accounting rewrite - BTREE_TRIGGER_ATOMIC: after combining our trigger callbacks, this makes our trigger context more explicit - A few fixes to avoid excessive transaction restarts on multithreaded workloads: fstests (in addition to ktest tests) are now checking slowpath counters, and that's shaking out a few bugs - Assorted tracepoint improvements - Starting to break up bcachefs_format.h and move on disk types so they're with the code they belong to; this will make room to start documenting the on disk format better. - A few minor fixes" * tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs: (46 commits) bcachefs: Improve inode_to_text() bcachefs: logged_ops_format.h bcachefs: reflink_format.h bcachefs; extents_format.h bcachefs: ec_format.h bcachefs: subvolume_format.h bcachefs: snapshot_format.h bcachefs: alloc_background_format.h bcachefs: xattr_format.h bcachefs: dirent_format.h bcachefs: inode_format.h bcachefs; quota_format.h bcachefs: sb-counters_format.h bcachefs: counters.c -> sb-counters.c bcachefs: comment bch_subvolume bcachefs: bch_snapshot::btime bcachefs: add missing __GFP_NOWARN bcachefs: opts->compression can now also be applied in the background bcachefs: Prep work for variable size btree node buffers bcachefs: grab s_umount only if snapshotting ... -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer updates from Thomas Gleixner: "Updates for time and clocksources: - A fix for the idle and iowait time accounting vs CPU hotplug. The time is reset on CPU hotplug which makes the accumulated systemwide time jump backwards. - Assorted fixes and improvements for clocksource/event drivers" * tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug clocksource/drivers/ep93xx: Fix error handling during probe clocksource/drivers/cadence-ttc: Fix some kernel-doc warnings clocksource/drivers/timer-ti-dm: Fix make W=n kerneldoc warnings clocksource/timer-riscv: Add riscv_clock_shutdown callback dt-bindings: timer: Add StarFive JH8100 clint dt-bindings: timer: thead,c900-aclint-mtimer: separate mtime and mtimecmp regs -
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull powerpc fixes from Aneesh Kumar: - Increase default stack size to 32KB for Book3S Thanks to Michael Ellerman. * tag 'powerpc-6.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64s: Increase default stack size to 32KB
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Kent Overstreet authored
Add line breaks - inode_to_text() is now much easier to read. Signed-off-by:Kent Overstreet <kent.overstreet@linux.dev>
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Kent Overstreet authored
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Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
bcachefs_format.h has gotten too big; let's do some organizing. Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Add a field to bch_snapshot for creation time; this will be important when we start exposing the snapshot tree to userspace. Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
The "apply this compression method in the background" paths now use the compression option if background_compression is not set; this means that setting or changing the compression option will cause existing data to be compressed accordingly in the background. Signed-off-by: -
Kent Overstreet authored
bcachefs btree nodes are big - typically 256k - and btree roots are pinned in memory. As we're now up to 18 btrees, we now have significant memory overhead in mostly empty btree roots. And in the future we're going to start enforcing that certain btree node boundaries exist, to solve lock contention issues - analagous to XFS's AGIs. Thus, we need to start allocating smaller btree node buffers when we can. This patch changes code that refers to the filesystem constant c->opts.btree_node_size to refer to the btree node buffer size - btree_buf_bytes() - where appropriate. Signed-off-by: -
Su Yue authored
When I was testing mongodb over bcachefs with compression, there is a lockdep warning when snapshotting mongodb data volume. $ cat test.sh prog=bcachefs $prog subvolume create /mnt/data $prog subvolume create /mnt/data/snapshots while true;do $prog subvolume snapshot /mnt/data /mnt/data/snapshots/$(date +%s) sleep 1s done $ cat /etc/mongodb.conf systemLog: destination: file logAppend: true path: /mnt/data/mongod.log storage: dbPath: /mnt/data/ lockdep reports: [ 3437.452330] ====================================================== [ 3437.452750] WARNING: possible circular locking dependency detected [ 3437.453168] 6.7.0-rc7-custom+ #85 Tainted: G E [ 3437.453562] ------------------------------------------------------ [ 3437.453981] bcachefs/35533 is trying to acquire lock: [ 3437.454325] ffffa0a02b2b1418 (sb_writers#10){.+.+}-{0:0}, at: filename_create+0x62/0x190 [ 3437.454875] but task is already holding lock: [ 3437.455268] ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.456009] which lock already depends on the new lock. [ 3437.456553] the existing dependency chain (in reverse order) is: [ 3437.457054] -> #3 (&type->s_umount_key#48){.+.+}-{3:3}: [ 3437.457507] down_read+0x3e/0x170 [ 3437.457772] bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.458206] __x64_sys_ioctl+0x93/0xd0 [ 3437.458498] do_syscall_64+0x42/0xf0 [ 3437.458779] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.459155] -> #2 (&c->snapshot_create_lock){++++}-{3:3}: [ 3437.459615] down_read+0x3e/0x170 [ 3437.459878] bch2_truncate+0x82/0x110 [bcachefs] [ 3437.460276] bchfs_truncate+0x254/0x3c0 [bcachefs] [ 3437.460686] notify_change+0x1f1/0x4a0 [ 3437.461283] do_truncate+0x7f/0xd0 [ 3437.461555] path_openat+0xa57/0xce0 [ 3437.461836] do_filp_open+0xb4/0x160 [ 3437.462116] do_sys_openat2+0x91/0xc0 [ 3437.462402] __x64_sys_openat+0x53/0xa0 [ 3437.462701] do_syscall_64+0x42/0xf0 [ 3437.462982] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.463359] -> #1 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}: [ 3437.463843] down_write+0x3b/0xc0 [ 3437.464223] bch2_write_iter+0x5b/0xcc0 [bcachefs] [ 3437.464493] vfs_write+0x21b/0x4c0 [ 3437.464653] ksys_write+0x69/0xf0 [ 3437.464839] do_syscall_64+0x42/0xf0 [ 3437.465009] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.465231] -> #0 (sb_writers#10){.+.+}-{0:0}: [ 3437.465471] __lock_acquire+0x1455/0x21b0 [ 3437.465656] lock_acquire+0xc6/0x2b0 [ 3437.465822] mnt_want_write+0x46/0x1a0 [ 3437.465996] filename_create+0x62/0x190 [ 3437.466175] user_path_create+0x2d/0x50 [ 3437.466352] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs] [ 3437.466617] __x64_sys_ioctl+0x93/0xd0 [ 3437.466791] do_syscall_64+0x42/0xf0 [ 3437.466957] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.467180] other info that might help us debug this: [ 3437.469670] 2 locks held by bcachefs/35533: other info that might help us debug this: [ 3437.467507] Chain exists of: sb_writers#10 --> &c->snapshot_create_lock --> &type->s_umount_key#48 [ 3437.467979] Possible unsafe locking scenario: [ 3437.468223] CPU0 CPU1 [ 3437.468405] ---- ---- [ 3437.468585] rlock(&type->s_umount_key#48); [ 3437.468758] lock(&c->snapshot_create_lock); [ 3437.469030] lock(&type->s_umount_key#48); [ 3437.469291] rlock(sb_writers#10); [ 3437.469434] *** DEADLOCK *** [ 3437.469670] 2 locks held by bcachefs/35533: [ 3437.469838] #0: ffffa0a02ce00a88 (&c->snapshot_create_lock){++++}-{3:3}, at: bch2_fs_file_ioctl+0x1e3/0xc90 [bcachefs] [ 3437.470294] #1: ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.470744] stack backtrace: [ 3437.470922] CPU: 7 PID: 35533 Comm: bcachefs Kdump: loaded Tainted: G E 6.7.0-rc7-custom+ #85 [ 3437.471313] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 3437.471694] Call Trace: [ 3437.471795] <TASK> [ 3437.471884] dump_stack_lvl+0x57/0x90 [ 3437.472035] check_noncircular+0x132/0x150 [ 3437.472202] __lock_acquire+0x1455/0x21b0 [ 3437.472369] lock_acquire+0xc6/0x2b0 [ 3437.472518] ? filename_create+0x62/0x190 [ 3437.472683] ? lock_is_held_type+0x97/0x110 [ 3437.472856] mnt_want_write+0x46/0x1a0 [ 3437.473025] ? filename_create+0x62/0x190 [ 3437.473204] filename_create+0x62/0x190 [ 3437.473380] user_path_create+0x2d/0x50 [ 3437.473555] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs] [ 3437.473819] ? lock_acquire+0xc6/0x2b0 [ 3437.474002] ? __fget_files+0x2a/0x190 [ 3437.474195] ? __fget_files+0xbc/0x190 [ 3437.474380] ? lock_release+0xc5/0x270 [ 3437.474567] ? __x64_sys_ioctl+0x93/0xd0 [ 3437.474764] ? __pfx_bch2_fs_file_ioctl+0x10/0x10 [bcachefs] [ 3437.475090] __x64_sys_ioctl+0x93/0xd0 [ 3437.475277] do_syscall_64+0x42/0xf0 [ 3437.475454] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.475691] RIP: 0033:0x7f2743c313af ====================================================== In __bch2_ioctl_subvolume_create(), we grab s_umount unconditionally and unlock it at the end of the function. There is a comment "why do we need this lock?" about the lock coming from commit 42d23732 ("bcachefs: Snapshot creation, deletion") The reason is that __bch2_ioctl_subvolume_create() calls sync_inodes_sb() which enforce locked s_umount to writeback all dirty nodes before doing snapshot works. Fix it by read locking s_umount for snapshotting only and unlocking s_umount after sync_inodes_sb(). Signed-off-by:Su Yue <glass.su@suse.com> Signed-off-by:
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Su Yue authored
bch_fs::snapshots is allocated by kvzalloc in __snapshot_t_mut. It should be freed by kvfree not kfree. Or umount will triger: [ 406.829178 ] BUG: unable to handle page fault for address: ffffe7b487148008 [ 406.830676 ] #PF: supervisor read access in kernel mode [ 406.831643 ] #PF: error_code(0x0000) - not-present page [ 406.832487 ] PGD 0 P4D 0 [ 406.832898 ] Oops: 0000 [#1] PREEMPT SMP PTI [ 406.833512 ] CPU: 2 PID: 1754 Comm: umount Kdump: loaded Tainted: G OE 6.7.0-rc7-custom+ #90 [ 406.834746 ] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 406.835796 ] RIP: 0010:kfree+0x62/0x140 [ 406.836197 ] Code: 80 48 01 d8 0f 82 e9 00 00 00 48 c7 c2 00 00 00 80 48 2b 15 78 9f 1f 01 48 01 d0 48 c1 e8 0c 48 c1 e0 06 48 03 05 56 9f 1f 01 <48> 8b 50 08 48 89 c7 f6 c2 01 0f 85 b0 00 00 00 66 90 48 8b 07 f6 [ 406.837810 ] RSP: 0018:ffffb9d641607e48 EFLAGS: 00010286 [ 406.838213 ] RAX: ffffe7b487148000 RBX: ffffb9d645200000 RCX: ffffb9d641607dc4 [ 406.838738 ] RDX: 000065bb00000000 RSI: ffffffffc0d88b84 RDI: ffffb9d645200000 [ 406.839217 ] RBP: ffff9a4625d00068 R08: 0000000000000001 R09: 0000000000000001 [ 406.839650 ] R10: 0000000000000001 R11: 000000000000001f R12: ffff9a4625d4da80 [ 406.840055 ] R13: ffff9a4625d00000 R14: ffffffffc0e2eb20 R15: 0000000000000000 [ 406.840451 ] FS: 00007f0a264ffb80(0000) GS:ffff9a4e2d500000(0000) knlGS:0000000000000000 [ 406.840851 ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 406.841125 ] CR2: ffffe7b487148008 CR3: 000000018c4d2000 CR4: 00000000000006f0 [ 406.841464 ] Call Trace: [ 406.841583 ] <TASK> [ 406.841682 ] ? __die+0x1f/0x70 [ 406.841828 ] ? page_fault_oops+0x159/0x470 [ 406.842014 ] ? fixup_exception+0x22/0x310 [ 406.842198 ] ? exc_page_fault+0x1ed/0x200 [ 406.842382 ] ? asm_exc_page_fault+0x22/0x30 [ 406.842574 ] ? bch2_fs_release+0x54/0x280 [bcachefs] [ 406.842842 ] ? kfree+0x62/0x140 [ 406.842988 ] ? kfree+0x104/0x140 [ 406.843138 ] bch2_fs_release+0x54/0x280 [bcachefs] [ 406.843390 ] kobject_put+0xb7/0x170 [ 406.843552 ] deactivate_locked_super+0x2f/0xa0 [ 406.843756 ] cleanup_mnt+0xba/0x150 [ 406.843917 ] task_work_run+0x59/0xa0 [ 406.844083 ] exit_to_user_mode_prepare+0x197/0x1a0 [ 406.844302 ] syscall_exit_to_user_mode+0x16/0x40 [ 406.844510 ] do_syscall_64+0x4e/0xf0 [ 406.844675 ] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 406.844907 ] RIP: 0033:0x7f0a2664e4fb Signed-off-by:
Brian Foster <bfoster@redhat.com> Signed-off-by:
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Kent Overstreet authored
Fixes: 023f9ac9 bcachefs: Delete dio read alignment check Reported-by:
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Colin Ian King authored
The variable tmp is being assigned a value but it isn't being read afterwards. The assignment is redundant and so tmp can be removed. Cleans up clang scan build warning: warning: Although the value stored to 'ret' is used in the enclosing expression, the value is never actually read from 'ret' [deadcode.DeadStores] Signed-off-by:
Colin Ian King <colin.i.king@gmail.com> Reviewed-by:
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Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
drop_locks_do() should not be used in a fastpath without first trying the do in nonblocking mode - the unlock and relock will cause excessive transaction restarts and potentially livelocking with other threads that are contending for the same locks. Signed-off-by: -
Kent Overstreet authored
Signed-off-by:
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