From dd47c104533dedb90434a3f142e94a671ac623a6 Mon Sep 17 00:00:00 2001 From: Eugene Syromiatnikov Date: Mon, 13 Sep 2021 17:44:15 +0200 Subject: io-wq: provide IO_WQ_* constants for IORING_REGISTER_IOWQ_MAX_WORKERS arg items The items passed in the array pointed by the arg parameter of IORING_REGISTER_IOWQ_MAX_WORKERS io_uring_register operation carry certain semantics: they refer to different io-wq worker categories; provide IO_WQ_* constants in the UAPI, so these categories can be referenced in the user space code. Suggested-by: Jens Axboe Complements: 2e480058ddc21ec5 ("io-wq: provide a way to limit max number of workers") Signed-off-by: Eugene Syromiatnikov Link: https://lore.kernel.org/r/20210913154415.GA12890@asgard.redhat.com Signed-off-by: Jens Axboe --- include/uapi/linux/io_uring.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 59ef35154e3d..b270a07b285e 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -317,13 +317,19 @@ enum { IORING_REGISTER_IOWQ_AFF = 17, IORING_UNREGISTER_IOWQ_AFF = 18, - /* set/get max number of workers */ + /* set/get max number of io-wq workers */ IORING_REGISTER_IOWQ_MAX_WORKERS = 19, /* this goes last */ IORING_REGISTER_LAST }; +/* io-wq worker categories */ +enum { + IO_WQ_BOUND, + IO_WQ_UNBOUND, +}; + /* deprecated, see struct io_uring_rsrc_update */ struct io_uring_files_update { __u32 offset; -- cgit v1.2.3 From 099dd788e31b4f426ef49c2785069804925a84e1 Mon Sep 17 00:00:00 2001 From: Steve French Date: Mon, 13 Sep 2021 14:51:10 -0500 Subject: cifs: remove pathname for file from SPDX header checkpatch complains about source files with filenames (e.g. in these cases just below the SPDX header in comments at the top of various files in fs/cifs). It also is helpful to change this now so will be less confusing when the parent directory is renamed e.g. from fs/cifs to fs/smb_client (or fs/smbfs) Reviewed-by: Ronnie Sahlberg Signed-off-by: Steve French --- include/uapi/linux/cifs/cifs_mount.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/cifs/cifs_mount.h b/include/uapi/linux/cifs/cifs_mount.h index 69829205fdb5..8e87d27b0951 100644 --- a/include/uapi/linux/cifs/cifs_mount.h +++ b/include/uapi/linux/cifs/cifs_mount.h @@ -1,6 +1,5 @@ /* SPDX-License-Identifier: LGPL-2.1+ WITH Linux-syscall-note */ /* - * include/uapi/linux/cifs/cifs_mount.h * * Author(s): Scott Lovenberg (scott.lovenberg@gmail.com) * -- cgit v1.2.3 From b564171ade70570b7f335fa8ed17adb28409e3ac Mon Sep 17 00:00:00 2001 From: Li Li Date: Fri, 10 Sep 2021 09:42:10 -0700 Subject: binder: fix freeze race Currently cgroup freezer is used to freeze the application threads, and BINDER_FREEZE is used to freeze the corresponding binder interface. There's already a mechanism in ioctl(BINDER_FREEZE) to wait for any existing transactions to drain out before actually freezing the binder interface. But freezing an app requires 2 steps, freezing the binder interface with ioctl(BINDER_FREEZE) and then freezing the application main threads with cgroupfs. This is not an atomic operation. The following race issue might happen. 1) Binder interface is frozen by ioctl(BINDER_FREEZE); 2) Main thread A initiates a new sync binder transaction to process B; 3) Main thread A is frozen by "echo 1 > cgroup.freeze"; 4) The response from process B reaches the frozen thread, which will unexpectedly fail. This patch provides a mechanism to check if there's any new pending transaction happening between ioctl(BINDER_FREEZE) and freezing the main thread. If there's any, the main thread freezing operation can be rolled back to finish the pending transaction. Furthermore, the response might reach the binder driver before the rollback actually happens. That will still cause failed transaction. As the other process doesn't wait for another response of the response, the response transaction failure can be fixed by treating the response transaction like an oneway/async one, allowing it to reach the frozen thread. And it will be consumed when the thread gets unfrozen later. NOTE: This patch reuses the existing definition of struct binder_frozen_status_info but expands the bit assignments of __u32 member sync_recv. To ensure backward compatibility, bit 0 of sync_recv still indicates there's an outstanding sync binder transaction. This patch adds new information to bit 1 of sync_recv, indicating the binder transaction happens exactly when there's a race. If an existing userspace app runs on a new kernel, a sync binder call will set bit 0 of sync_recv so ioctl(BINDER_GET_FROZEN_INFO) still return the expected value (true). The app just doesn't check bit 1 intentionally so it doesn't have the ability to tell if there's a race. This behavior is aligned with what happens on an old kernel which doesn't set bit 1 at all. A new userspace app can 1) check bit 0 to know if there's a sync binder transaction happened when being frozen - same as before; and 2) check bit 1 to know if that sync binder transaction happened exactly when there's a race - a new information for rollback decision. the same time, confirmed the pending transactions succeeded. Fixes: 432ff1e91694 ("binder: BINDER_FREEZE ioctl") Acked-by: Todd Kjos Cc: stable Signed-off-by: Li Li Test: stress test with apps being frozen and initiating binder calls at Link: https://lore.kernel.org/r/20210910164210.2282716-2-dualli@chromium.org Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/android/binder.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/android/binder.h b/include/uapi/linux/android/binder.h index 20e435fe657a..3246f2c74696 100644 --- a/include/uapi/linux/android/binder.h +++ b/include/uapi/linux/android/binder.h @@ -225,7 +225,14 @@ struct binder_freeze_info { struct binder_frozen_status_info { __u32 pid; + + /* process received sync transactions since last frozen + * bit 0: received sync transaction after being frozen + * bit 1: new pending sync transaction during freezing + */ __u32 sync_recv; + + /* process received async transactions since last frozen */ __u32 async_recv; }; -- cgit v1.2.3