[PATCH 2/2] Filesystem: Add kernel event filter handler
Gedare Bloom
gedare at rtems.org
Thu Oct 31 15:03:43 UTC 2013
On Thu, Oct 31, 2013 at 10:49 AM, Sebastian Huber
<sebastian.huber at embedded-brains.de> wrote:
> This handler is necessary to implement the KQUEUE(2) system calls.
>
> Add <sys/event.h> from FreeBSD 8.3.
> ---
> cpukit/Makefile.am | 1 +
> cpukit/libcsupport/include/rtems/libio.h | 31 +++
> cpukit/libcsupport/include/sys/event.h | 279 ++++++++++++++++++++++++++
> cpukit/libfs/Makefile.am | 1 +
> cpukit/libfs/src/defaults/default_kqfilter.c | 38 ++++
> cpukit/preinstall.am | 4 +
> 6 files changed, 354 insertions(+), 0 deletions(-)
> create mode 100644 cpukit/libcsupport/include/sys/event.h
> create mode 100644 cpukit/libfs/src/defaults/default_kqfilter.c
>
> diff --git a/cpukit/Makefile.am b/cpukit/Makefile.am
> index 443ed35..3e26cac 100644
> --- a/cpukit/Makefile.am
> +++ b/cpukit/Makefile.am
> @@ -50,6 +50,7 @@ include_HEADERS += libmd/md4.h
> include_HEADERS += libmd/md5.h
>
> include_sys_HEADERS += libcsupport/include/sys/ioccom.h
> +include_sys_HEADERS += libcsupport/include/sys/event.h
> include_sys_HEADERS += libcsupport/include/sys/filio.h
> include_sys_HEADERS += libcsupport/include/sys/ioctl.h
> include_sys_HEADERS += libcsupport/include/sys/poll.h
> diff --git a/cpukit/libcsupport/include/rtems/libio.h b/cpukit/libcsupport/include/rtems/libio.h
> index a642062..21d57eb 100644
> --- a/cpukit/libcsupport/include/rtems/libio.h
> +++ b/cpukit/libcsupport/include/rtems/libio.h
> @@ -41,6 +41,8 @@
> extern "C" {
> #endif
>
> +struct knote;
> +
> /**
> * @defgroup LibIOFSOps File System Operations
> *
> @@ -958,6 +960,22 @@ typedef int (*rtems_filesystem_poll_t)(
> );
>
> /**
> + * @brief Kernel event filter support.
> + *
> + * @param[in, out] iop The IO pointer.
> + * @param[in] kn The kernel event note.
> + *
> + * @retval 0 Successful operation.
> + * @retval error An error occurred. This is usually EINVAL.
> + *
> + * @see rtems_filesystem_default_kqfilter().
> + */
> +typedef int (*rtems_filesystem_kqfilter_t)(
> + rtems_libio_t *iop,
> + struct knote *kn
> +);
> +
> +/**
> * @brief File system node operations table.
> */
> struct _rtems_filesystem_file_handlers_r {
> @@ -973,6 +991,7 @@ struct _rtems_filesystem_file_handlers_r {
> rtems_filesystem_fdatasync_t fdatasync_h;
> rtems_filesystem_fcntl_t fcntl_h;
> rtems_filesystem_poll_t poll_h;
> + rtems_filesystem_kqfilter_t kqfilter_h;
> };
>
> /**
> @@ -1158,6 +1177,18 @@ int rtems_filesystem_default_poll(
> int events
> );
>
> +/**
> + * @brief Default kernel event filter handler.
> + *
> + * @retval EINVAL Always.
> + *
> + * @see rtems_filesystem_kqfilter_t.
> + */
> +int rtems_filesystem_default_kqfilter(
> + rtems_libio_t *iop,
> + struct knote *kn
> +);
> +
> /** @} */
>
> /**
> diff --git a/cpukit/libcsupport/include/sys/event.h b/cpukit/libcsupport/include/sys/event.h
> new file mode 100644
> index 0000000..d92eb55
> --- /dev/null
> +++ b/cpukit/libcsupport/include/sys/event.h
> @@ -0,0 +1,279 @@
> +/*-
> + * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon at FreeBSD.org>
> + * All rights reserved.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + * notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + * notice, this list of conditions and the following disclaimer in the
> + * documentation and/or other materials provided with the distribution.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + *
> + * $FreeBSD$
> + */
> +
> +#ifndef _SYS_EVENT_H_
> +#define _SYS_EVENT_H_
> +
> +#include <sys/queue.h>
I don't think we have this include file in RTEMS?
> +
> +#define EVFILT_READ (-1)
> +#define EVFILT_WRITE (-2)
> +#define EVFILT_AIO (-3) /* attached to aio requests */
> +#define EVFILT_VNODE (-4) /* attached to vnodes */
> +#define EVFILT_PROC (-5) /* attached to struct proc */
> +#define EVFILT_SIGNAL (-6) /* attached to struct proc */
> +#define EVFILT_TIMER (-7) /* timers */
> +/* EVFILT_NETDEV (-8) no longer supported */
> +#define EVFILT_FS (-9) /* filesystem events */
> +#define EVFILT_LIO (-10) /* attached to lio requests */
> +#define EVFILT_USER (-11) /* User events */
> +#define EVFILT_SYSCOUNT 11
> +
> +#define EV_SET(kevp_, a, b, c, d, e, f) do { \
> + struct kevent *kevp = (kevp_); \
> + (kevp)->ident = (a); \
> + (kevp)->filter = (b); \
> + (kevp)->flags = (c); \
> + (kevp)->fflags = (d); \
> + (kevp)->data = (e); \
> + (kevp)->udata = (f); \
> +} while(0)
> +
> +struct kevent {
> + uintptr_t ident; /* identifier for this event */
> + short filter; /* filter for event */
> + u_short flags;
> + u_int fflags;
> + intptr_t data;
> + void *udata; /* opaque user data identifier */
> +};
> +
> +/* actions */
> +#define EV_ADD 0x0001 /* add event to kq (implies enable) */
> +#define EV_DELETE 0x0002 /* delete event from kq */
> +#define EV_ENABLE 0x0004 /* enable event */
> +#define EV_DISABLE 0x0008 /* disable event (not reported) */
> +
> +/* flags */
> +#define EV_ONESHOT 0x0010 /* only report one occurrence */
> +#define EV_CLEAR 0x0020 /* clear event state after reporting */
> +#define EV_RECEIPT 0x0040 /* force EV_ERROR on success, data=0 */
> +#define EV_DISPATCH 0x0080 /* disable event after reporting */
> +
> +#define EV_SYSFLAGS 0xF000 /* reserved by system */
> +#define EV_FLAG1 0x2000 /* filter-specific flag */
> +
> +/* returned values */
> +#define EV_EOF 0x8000 /* EOF detected */
> +#define EV_ERROR 0x4000 /* error, data contains errno */
> +
> + /*
> + * data/hint flags/masks for EVFILT_USER, shared with userspace
> + *
> + * On input, the top two bits of fflags specifies how the lower twenty four
> + * bits should be applied to the stored value of fflags.
> + *
> + * On output, the top two bits will always be set to NOTE_FFNOP and the
> + * remaining twenty four bits will contain the stored fflags value.
> + */
> +#define NOTE_FFNOP 0x00000000 /* ignore input fflags */
> +#define NOTE_FFAND 0x40000000 /* AND fflags */
> +#define NOTE_FFOR 0x80000000 /* OR fflags */
> +#define NOTE_FFCOPY 0xc0000000 /* copy fflags */
> +#define NOTE_FFCTRLMASK 0xc0000000 /* masks for operations */
> +#define NOTE_FFLAGSMASK 0x00ffffff
> +
> +#define NOTE_TRIGGER 0x01000000 /* Cause the event to be
> + triggered for output. */
> +
> +/*
> + * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
> + */
> +#define NOTE_LOWAT 0x0001 /* low water mark */
> +
> +/*
> + * data/hint flags for EVFILT_VNODE, shared with userspace
> + */
> +#define NOTE_DELETE 0x0001 /* vnode was removed */
> +#define NOTE_WRITE 0x0002 /* data contents changed */
> +#define NOTE_EXTEND 0x0004 /* size increased */
> +#define NOTE_ATTRIB 0x0008 /* attributes changed */
> +#define NOTE_LINK 0x0010 /* link count changed */
> +#define NOTE_RENAME 0x0020 /* vnode was renamed */
> +#define NOTE_REVOKE 0x0040 /* vnode access was revoked */
> +
> +/*
> + * data/hint flags for EVFILT_PROC, shared with userspace
> + */
> +#define NOTE_EXIT 0x80000000 /* process exited */
> +#define NOTE_FORK 0x40000000 /* process forked */
> +#define NOTE_EXEC 0x20000000 /* process exec'd */
> +#define NOTE_PCTRLMASK 0xf0000000 /* mask for hint bits */
> +#define NOTE_PDATAMASK 0x000fffff /* mask for pid */
> +
> +/* additional flags for EVFILT_PROC */
> +#define NOTE_TRACK 0x00000001 /* follow across forks */
> +#define NOTE_TRACKERR 0x00000002 /* could not track child */
> +#define NOTE_CHILD 0x00000004 /* am a child process */
> +
> +struct knote;
> +SLIST_HEAD(klist, knote);
> +struct kqueue;
> +SLIST_HEAD(kqlist, kqueue);
> +struct knlist {
> + struct klist kl_list;
> + void (*kl_lock)(void *); /* lock function */
> + void (*kl_unlock)(void *);
> + void (*kl_assert_locked)(void *);
> + void (*kl_assert_unlocked)(void *);
> + void *kl_lockarg; /* argument passed to kl_lockf() */
> +};
> +
> +
> +#ifdef _KERNEL
> +
> +#ifdef MALLOC_DECLARE
> +MALLOC_DECLARE(M_KQUEUE);
> +#endif
> +
> +/*
> + * Flags for knote call
> + */
> +#define KNF_LISTLOCKED 0x0001 /* knlist is locked */
> +#define KNF_NOKQLOCK 0x0002 /* do not keep KQ_LOCK */
> +
> +#define KNOTE(list, hist, flags) knote(list, hist, flags)
> +#define KNOTE_LOCKED(list, hint) knote(list, hint, KNF_LISTLOCKED)
> +#define KNOTE_UNLOCKED(list, hint) knote(list, hint, 0)
> +
> +#define KNLIST_EMPTY(list) SLIST_EMPTY(&(list)->kl_list)
> +
> +/*
> + * Flag indicating hint is a signal. Used by EVFILT_SIGNAL, and also
> + * shared by EVFILT_PROC (all knotes attached to p->p_klist)
> + */
> +#define NOTE_SIGNAL 0x08000000
> +
> +/*
> + * Hint values for the optional f_touch event filter. If f_touch is not set
> + * to NULL and f_isfd is zero the f_touch filter will be called with the type
> + * argument set to EVENT_REGISTER during a kevent() system call. It is also
> + * called under the same conditions with the type argument set to EVENT_PROCESS
> + * when the event has been triggered.
> + */
> +#define EVENT_REGISTER 1
> +#define EVENT_PROCESS 2
> +
> +struct filterops {
> + int f_isfd; /* true if ident == filedescriptor */
> + int (*f_attach)(struct knote *kn);
> + void (*f_detach)(struct knote *kn);
> + int (*f_event)(struct knote *kn, long hint);
> + void (*f_touch)(struct knote *kn, struct kevent *kev, u_long type);
> +};
> +
> +/*
> + * Setting the KN_INFLUX flag enables you to unlock the kq that this knote
> + * is on, and modify kn_status as if you had the KQ lock.
> + *
> + * kn_sfflags, kn_sdata, and kn_kevent are protected by the knlist lock.
> + */
> +struct knote {
> + SLIST_ENTRY(knote) kn_link; /* for kq */
> + SLIST_ENTRY(knote) kn_selnext; /* for struct selinfo */
> + struct knlist *kn_knlist; /* f_attach populated */
> + TAILQ_ENTRY(knote) kn_tqe;
> + struct kqueue *kn_kq; /* which queue we are on */
> + struct kevent kn_kevent;
> + int kn_status; /* protected by kq lock */
> +#define KN_ACTIVE 0x01 /* event has been triggered */
> +#define KN_QUEUED 0x02 /* event is on queue */
> +#define KN_DISABLED 0x04 /* event is disabled */
> +#define KN_DETACHED 0x08 /* knote is detached */
> +#define KN_INFLUX 0x10 /* knote is in flux */
> +#define KN_MARKER 0x20 /* ignore this knote */
> +#define KN_KQUEUE 0x40 /* this knote belongs to a kq */
> +#define KN_HASKQLOCK 0x80 /* for _inevent */
> + int kn_sfflags; /* saved filter flags */
> + intptr_t kn_sdata; /* saved data field */
> + union {
> + struct file *p_fp; /* file data pointer */
> + struct proc *p_proc; /* proc pointer */
> + struct aiocblist *p_aio; /* AIO job pointer */
> + struct aioliojob *p_lio; /* LIO job pointer */
> + } kn_ptr;
> + struct filterops *kn_fop;
> + void *kn_hook;
> + int kn_hookid;
> +
> +#define kn_id kn_kevent.ident
> +#define kn_filter kn_kevent.filter
> +#define kn_flags kn_kevent.flags
> +#define kn_fflags kn_kevent.fflags
> +#define kn_data kn_kevent.data
> +#define kn_fp kn_ptr.p_fp
> +};
> +struct kevent_copyops {
> + void *arg;
> + int (*k_copyout)(void *arg, struct kevent *kevp, int count);
> + int (*k_copyin)(void *arg, struct kevent *kevp, int count);
> +};
> +
> +struct thread;
> +struct proc;
> +struct knlist;
> +struct mtx;
> +
> +extern void knote(struct knlist *list, long hint, int lockflags);
> +extern void knote_fork(struct knlist *list, int pid);
> +extern void knlist_add(struct knlist *knl, struct knote *kn, int islocked);
> +extern void knlist_remove(struct knlist *knl, struct knote *kn, int islocked);
> +extern void knlist_remove_inevent(struct knlist *knl, struct knote *kn);
> +extern int knlist_empty(struct knlist *knl);
> +extern void knlist_init(struct knlist *knl, void *lock,
> + void (*kl_lock)(void *), void (*kl_unlock)(void *),
> + void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *));
> +extern void knlist_init_mtx(struct knlist *knl, struct mtx *lock);
> +extern void knlist_destroy(struct knlist *knl);
> +extern void knlist_cleardel(struct knlist *knl, struct thread *td,
> + int islocked, int killkn);
> +#define knlist_clear(knl, islocked) \
> + knlist_cleardel((knl), NULL, (islocked), 0)
> +#define knlist_delete(knl, td, islocked) \
> + knlist_cleardel((knl), (td), (islocked), 1)
> +extern void knote_fdclose(struct thread *p, int fd);
> +extern int kqfd_register(int fd, struct kevent *kev, struct thread *p,
> + int waitok);
> +extern int kqueue_add_filteropts(int filt, struct filterops *filtops);
> +extern int kqueue_del_filteropts(int filt);
> +
> +#else /* !_KERNEL */
> +
> +#include <sys/cdefs.h>
> +struct timespec;
> +
> +__BEGIN_DECLS
> +int kqueue(void);
> +int kevent(int kq, const struct kevent *changelist, int nchanges,
> + struct kevent *eventlist, int nevents,
> + const struct timespec *timeout);
> +__END_DECLS
> +
> +#endif /* !_KERNEL */
> +
> +#endif /* !_SYS_EVENT_H_ */
> diff --git a/cpukit/libfs/Makefile.am b/cpukit/libfs/Makefile.am
> index b8496d5..21bb7ef 100644
> --- a/cpukit/libfs/Makefile.am
> +++ b/cpukit/libfs/Makefile.am
> @@ -33,6 +33,7 @@ libdefaultfs_a_SOURCES = \
> src/defaults/default_node_type.c \
> src/defaults/default_ftruncate_directory.c \
> src/defaults/default_handlers.c src/defaults/default_ops.c
> +libdefaultfs_a_SOURCES += src/defaults/default_kqfilter.c
> libdefaultfs_a_SOURCES += src/defaults/default_poll.c
>
> noinst_LIBRARIES += libimfs.a
> diff --git a/cpukit/libfs/src/defaults/default_kqfilter.c b/cpukit/libfs/src/defaults/default_kqfilter.c
> new file mode 100644
> index 0000000..6c84539
> --- /dev/null
> +++ b/cpukit/libfs/src/defaults/default_kqfilter.c
> @@ -0,0 +1,38 @@
> +/**
> + * @file
> + *
> + * @brief Default Kernel Event Filter Handler
> + *
> + * @ingroup LibIOFSHandler
> + */
> +
> +/*
> + * Copyright (c) 2013 embedded brains GmbH. All rights reserved.
> + *
> + * embedded brains GmbH
> + * Dornierstr. 4
> + * 82178 Puchheim
> + * Germany
> + * <rtems at embedded-brains.de>
> + *
> + * The license and distribution terms for this file may be
> + * found in the file LICENSE in this distribution or at
> + * http://www.rtems.com/license/LICENSE.
> + */
> +
> +#if HAVE_CONFIG_H
> + #include "config.h"
> +#endif
> +
> +#include <rtems/libio_.h>
> +
> +#include <sys/types.h>
> +#include <sys/event.h>
> +
> +int rtems_filesystem_default_kqfilter(
> + rtems_libio_t *iop,
> + struct knote *kn
> +)
> +{
> + return EINVAL;
> +}
> diff --git a/cpukit/preinstall.am b/cpukit/preinstall.am
> index bdcc359..4e80a3f 100644
> --- a/cpukit/preinstall.am
> +++ b/cpukit/preinstall.am
> @@ -68,6 +68,10 @@ $(PROJECT_INCLUDE)/sys/ioccom.h: libcsupport/include/sys/ioccom.h $(PROJECT_INCL
> $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/sys/ioccom.h
> PREINSTALL_FILES += $(PROJECT_INCLUDE)/sys/ioccom.h
>
> +$(PROJECT_INCLUDE)/sys/event.h: libcsupport/include/sys/event.h $(PROJECT_INCLUDE)/sys/$(dirstamp)
> + $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/sys/event.h
> +PREINSTALL_FILES += $(PROJECT_INCLUDE)/sys/event.h
> +
> $(PROJECT_INCLUDE)/sys/filio.h: libcsupport/include/sys/filio.h $(PROJECT_INCLUDE)/sys/$(dirstamp)
> $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/sys/filio.h
> PREINSTALL_FILES += $(PROJECT_INCLUDE)/sys/filio.h
> --
> 1.7.7
>
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