X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/0c530ab8987f0ae6a1a3d9284f40182b88852816..4ba76501152d51ccb5647018f3192c6096367d48:/bsd/miscfs/specfs/spec_vnops.c
diff --git a/bsd/miscfs/specfs/spec_vnops.c b/bsd/miscfs/specfs/spec_vnops.c
index cf66f74c0..300894634 100644
--- a/bsd/miscfs/specfs/spec_vnops.c
+++ b/bsd/miscfs/specfs/spec_vnops.c
@@ -1,23 +1,29 @@
/*
- * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2019 Apple Computer, Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
- *
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License"). You may not use this file except in compliance with the
- * License. Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
- *
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
@@ -63,8 +69,9 @@
#include <sys/conf.h>
#include <sys/buf_internal.h>
#include <sys/mount_internal.h>
-#include <sys/namei.h>
#include <sys/vnode_internal.h>
+#include <sys/file_internal.h>
+#include <sys/namei.h>
#include <sys/stat.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
@@ -73,121 +80,212 @@
#include <sys/malloc.h>
#include <sys/disk.h>
#include <sys/uio_internal.h>
+#include <sys/resource.h>
+#include <machine/machine_routines.h>
#include <miscfs/specfs/specdev.h>
#include <vfs/vfs_support.h>
+#include <vfs/vfs_disk_conditioner.h>
+
+#include <kern/assert.h>
+#include <kern/task.h>
+#include <kern/sched_prim.h>
+#include <kern/thread.h>
+#include <kern/policy_internal.h>
+#include <kern/timer_call.h>
+#include <kern/waitq.h>
+
+#include <pexpert/pexpert.h>
#include <sys/kdebug.h>
+#include <libkern/section_keywords.h>
+
+/* XXX following three prototypes should be in a header file somewhere */
+extern dev_t chrtoblk(dev_t dev);
+extern boolean_t iskmemdev(dev_t dev);
+extern int bpfkqfilter(dev_t dev, struct knote *kn);
+extern int ptsd_kqfilter(dev_t, struct knote *);
+extern int ptmx_kqfilter(dev_t, struct knote *);
struct vnode *speclisth[SPECHSZ];
/* symbolic sleep message strings for devices */
-char devopn[] = "devopn";
-char devio[] = "devio";
-char devwait[] = "devwait";
-char devin[] = "devin";
-char devout[] = "devout";
-char devioc[] = "devioc";
-char devcls[] = "devcls";
+char devopn[] = "devopn";
+char devio[] = "devio";
+char devwait[] = "devwait";
+char devin[] = "devin";
+char devout[] = "devout";
+char devioc[] = "devioc";
+char devcls[] = "devcls";
#define VOPFUNC int (*)(void *)
-int (**spec_vnodeop_p)(void *);
-struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
- { &vnop_default_desc, (VOPFUNC)vn_default_error },
- { &vnop_lookup_desc, (VOPFUNC)spec_lookup }, /* lookup */
- { &vnop_create_desc, (VOPFUNC)err_create }, /* create */
- { &vnop_mknod_desc, (VOPFUNC)err_mknod }, /* mknod */
- { &vnop_open_desc, (VOPFUNC)spec_open }, /* open */
- { &vnop_close_desc, (VOPFUNC)spec_close }, /* close */
- { &vnop_access_desc, (VOPFUNC)spec_access }, /* access */
- { &vnop_getattr_desc, (VOPFUNC)spec_getattr }, /* getattr */
- { &vnop_setattr_desc, (VOPFUNC)spec_setattr }, /* setattr */
- { &vnop_read_desc, (VOPFUNC)spec_read }, /* read */
- { &vnop_write_desc, (VOPFUNC)spec_write }, /* write */
- { &vnop_ioctl_desc, (VOPFUNC)spec_ioctl }, /* ioctl */
- { &vnop_select_desc, (VOPFUNC)spec_select }, /* select */
- { &vnop_revoke_desc, (VOPFUNC)nop_revoke }, /* revoke */
- { &vnop_mmap_desc, (VOPFUNC)err_mmap }, /* mmap */
- { &vnop_fsync_desc, (VOPFUNC)spec_fsync }, /* fsync */
- { &vnop_remove_desc, (VOPFUNC)err_remove }, /* remove */
- { &vnop_link_desc, (VOPFUNC)err_link }, /* link */
- { &vnop_rename_desc, (VOPFUNC)err_rename }, /* rename */
- { &vnop_mkdir_desc, (VOPFUNC)err_mkdir }, /* mkdir */
- { &vnop_rmdir_desc, (VOPFUNC)err_rmdir }, /* rmdir */
- { &vnop_symlink_desc, (VOPFUNC)err_symlink }, /* symlink */
- { &vnop_readdir_desc, (VOPFUNC)err_readdir }, /* readdir */
- { &vnop_readlink_desc, (VOPFUNC)err_readlink }, /* readlink */
- { &vnop_inactive_desc, (VOPFUNC)nop_inactive }, /* inactive */
- { &vnop_reclaim_desc, (VOPFUNC)nop_reclaim }, /* reclaim */
- { &vnop_strategy_desc, (VOPFUNC)spec_strategy }, /* strategy */
- { &vnop_pathconf_desc, (VOPFUNC)spec_pathconf }, /* pathconf */
- { &vnop_advlock_desc, (VOPFUNC)err_advlock }, /* advlock */
- { &vnop_bwrite_desc, (VOPFUNC)spec_bwrite }, /* bwrite */
- { &vnop_pagein_desc, (VOPFUNC)err_pagein }, /* Pagein */
- { &vnop_pageout_desc, (VOPFUNC)err_pageout }, /* Pageout */
- { &vnop_copyfile_desc, (VOPFUNC)err_copyfile }, /* Copyfile */
- { &vnop_blktooff_desc, (VOPFUNC)spec_blktooff }, /* blktooff */
- { &vnop_offtoblk_desc, (VOPFUNC)spec_offtoblk }, /* offtoblk */
- { &vnop_blockmap_desc, (VOPFUNC)spec_blockmap }, /* blockmap */
- { (struct vnodeop_desc*)NULL, (int(*)())NULL }
+int(**spec_vnodeop_p)(void *);
+const struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
+ { .opve_op = &vnop_default_desc, .opve_impl = (VOPFUNC)vn_default_error },
+ { .opve_op = &vnop_lookup_desc, .opve_impl = (VOPFUNC)spec_lookup }, /* lookup */
+ { .opve_op = &vnop_create_desc, .opve_impl = (VOPFUNC)err_create }, /* create */
+ { .opve_op = &vnop_mknod_desc, .opve_impl = (VOPFUNC)err_mknod }, /* mknod */
+ { .opve_op = &vnop_open_desc, .opve_impl = (VOPFUNC)spec_open }, /* open */
+ { .opve_op = &vnop_close_desc, .opve_impl = (VOPFUNC)spec_close }, /* close */
+ { .opve_op = &vnop_access_desc, .opve_impl = (VOPFUNC)spec_access }, /* access */
+ { .opve_op = &vnop_getattr_desc, .opve_impl = (VOPFUNC)spec_getattr }, /* getattr */
+ { .opve_op = &vnop_setattr_desc, .opve_impl = (VOPFUNC)spec_setattr }, /* setattr */
+ { .opve_op = &vnop_read_desc, .opve_impl = (VOPFUNC)spec_read }, /* read */
+ { .opve_op = &vnop_write_desc, .opve_impl = (VOPFUNC)spec_write }, /* write */
+ { .opve_op = &vnop_ioctl_desc, .opve_impl = (VOPFUNC)spec_ioctl }, /* ioctl */
+ { .opve_op = &vnop_select_desc, .opve_impl = (VOPFUNC)spec_select }, /* select */
+ { .opve_op = &vnop_revoke_desc, .opve_impl = (VOPFUNC)nop_revoke }, /* revoke */
+ { .opve_op = &vnop_mmap_desc, .opve_impl = (VOPFUNC)err_mmap }, /* mmap */
+ { .opve_op = &vnop_fsync_desc, .opve_impl = (VOPFUNC)spec_fsync }, /* fsync */
+ { .opve_op = &vnop_remove_desc, .opve_impl = (VOPFUNC)err_remove }, /* remove */
+ { .opve_op = &vnop_link_desc, .opve_impl = (VOPFUNC)err_link }, /* link */
+ { .opve_op = &vnop_rename_desc, .opve_impl = (VOPFUNC)err_rename }, /* rename */
+ { .opve_op = &vnop_mkdir_desc, .opve_impl = (VOPFUNC)err_mkdir }, /* mkdir */
+ { .opve_op = &vnop_rmdir_desc, .opve_impl = (VOPFUNC)err_rmdir }, /* rmdir */
+ { .opve_op = &vnop_symlink_desc, .opve_impl = (VOPFUNC)err_symlink }, /* symlink */
+ { .opve_op = &vnop_readdir_desc, .opve_impl = (VOPFUNC)err_readdir }, /* readdir */
+ { .opve_op = &vnop_readlink_desc, .opve_impl = (VOPFUNC)err_readlink }, /* readlink */
+ { .opve_op = &vnop_inactive_desc, .opve_impl = (VOPFUNC)nop_inactive }, /* inactive */
+ { .opve_op = &vnop_reclaim_desc, .opve_impl = (VOPFUNC)nop_reclaim }, /* reclaim */
+ { .opve_op = &vnop_strategy_desc, .opve_impl = (VOPFUNC)spec_strategy }, /* strategy */
+ { .opve_op = &vnop_pathconf_desc, .opve_impl = (VOPFUNC)spec_pathconf }, /* pathconf */
+ { .opve_op = &vnop_advlock_desc, .opve_impl = (VOPFUNC)err_advlock }, /* advlock */
+ { .opve_op = &vnop_bwrite_desc, .opve_impl = (VOPFUNC)spec_bwrite }, /* bwrite */
+ { .opve_op = &vnop_pagein_desc, .opve_impl = (VOPFUNC)err_pagein }, /* Pagein */
+ { .opve_op = &vnop_pageout_desc, .opve_impl = (VOPFUNC)err_pageout }, /* Pageout */
+ { .opve_op = &vnop_copyfile_desc, .opve_impl = (VOPFUNC)err_copyfile }, /* Copyfile */
+ { .opve_op = &vnop_blktooff_desc, .opve_impl = (VOPFUNC)spec_blktooff }, /* blktooff */
+ { .opve_op = &vnop_offtoblk_desc, .opve_impl = (VOPFUNC)spec_offtoblk }, /* offtoblk */
+ { .opve_op = &vnop_blockmap_desc, .opve_impl = (VOPFUNC)spec_blockmap }, /* blockmap */
+ { .opve_op = (struct vnodeop_desc*)NULL, .opve_impl = (int (*)(void *))NULL }
};
-struct vnodeopv_desc spec_vnodeop_opv_desc =
- { &spec_vnodeop_p, spec_vnodeop_entries };
+const struct vnodeopv_desc spec_vnodeop_opv_desc =
+{ .opv_desc_vector_p = &spec_vnodeop_p, .opv_desc_ops = spec_vnodeop_entries };
static void set_blocksize(vnode_t, dev_t);
+#define LOWPRI_TIER1_WINDOW_MSECS 25
+#define LOWPRI_TIER2_WINDOW_MSECS 100
+#define LOWPRI_TIER3_WINDOW_MSECS 500
+
+#define LOWPRI_TIER1_IO_PERIOD_MSECS 40
+#define LOWPRI_TIER2_IO_PERIOD_MSECS 85
+#define LOWPRI_TIER3_IO_PERIOD_MSECS 200
+
+#define LOWPRI_TIER1_IO_PERIOD_SSD_MSECS 5
+#define LOWPRI_TIER2_IO_PERIOD_SSD_MSECS 15
+#define LOWPRI_TIER3_IO_PERIOD_SSD_MSECS 25
+
+
+int throttle_windows_msecs[THROTTLE_LEVEL_END + 1] = {
+ 0,
+ LOWPRI_TIER1_WINDOW_MSECS,
+ LOWPRI_TIER2_WINDOW_MSECS,
+ LOWPRI_TIER3_WINDOW_MSECS,
+};
+
+int throttle_io_period_msecs[THROTTLE_LEVEL_END + 1] = {
+ 0,
+ LOWPRI_TIER1_IO_PERIOD_MSECS,
+ LOWPRI_TIER2_IO_PERIOD_MSECS,
+ LOWPRI_TIER3_IO_PERIOD_MSECS,
+};
+
+int throttle_io_period_ssd_msecs[THROTTLE_LEVEL_END + 1] = {
+ 0,
+ LOWPRI_TIER1_IO_PERIOD_SSD_MSECS,
+ LOWPRI_TIER2_IO_PERIOD_SSD_MSECS,
+ LOWPRI_TIER3_IO_PERIOD_SSD_MSECS,
+};
+
+
+int throttled_count[THROTTLE_LEVEL_END + 1];
+
+struct _throttle_io_info_t {
+ lck_mtx_t throttle_lock;
+
+ struct timeval throttle_last_write_timestamp;
+ struct timeval throttle_min_timer_deadline;
+ struct timeval throttle_window_start_timestamp[THROTTLE_LEVEL_END + 1]; /* window starts at both the beginning and completion of an I/O */
+ struct timeval throttle_last_IO_timestamp[THROTTLE_LEVEL_END + 1];
+ pid_t throttle_last_IO_pid[THROTTLE_LEVEL_END + 1];
+ struct timeval throttle_start_IO_period_timestamp[THROTTLE_LEVEL_END + 1];
+ int32_t throttle_inflight_count[THROTTLE_LEVEL_END + 1];
+
+ TAILQ_HEAD(, uthread) throttle_uthlist[THROTTLE_LEVEL_END + 1]; /* Lists of throttled uthreads */
+ int throttle_next_wake_level;
+
+ thread_call_t throttle_timer_call;
+ int32_t throttle_timer_ref;
+ int32_t throttle_timer_active;
+
+ int32_t throttle_io_count;
+ int32_t throttle_io_count_begin;
+ int *throttle_io_periods;
+ uint32_t throttle_io_period_num;
+
+ int32_t throttle_refcnt;
+ int32_t throttle_alloc;
+ int32_t throttle_disabled;
+ int32_t throttle_is_fusion_with_priority;
+};
+
+struct _throttle_io_info_t _throttle_io_info[LOWPRI_MAX_NUM_DEV];
+
+
+int lowpri_throttle_enabled = 1;
+
+
+static void throttle_info_end_io_internal(struct _throttle_io_info_t *info, int throttle_level);
+static int throttle_info_update_internal(struct _throttle_io_info_t *info, uthread_t ut, int flags, boolean_t isssd, boolean_t inflight, struct bufattr *bap);
+static int throttle_get_thread_throttle_level(uthread_t ut);
+static int throttle_get_thread_throttle_level_internal(uthread_t ut, int io_tier);
+void throttle_info_mount_reset_period(mount_t mp, int isssd);
/*
* Trivial lookup routine that always fails.
*/
int
-spec_lookup(ap)
- struct vnop_lookup_args /* {
- struct vnode *a_dvp;
- struct vnode **a_vpp;
- struct componentname *a_cnp;
- vfs_context_t a_context;
- } */ *ap;
+spec_lookup(struct vnop_lookup_args *ap)
{
-
*ap->a_vpp = NULL;
- return (ENOTDIR);
+ return ENOTDIR;
}
static void
set_blocksize(struct vnode *vp, dev_t dev)
{
- int (*size)(dev_t);
- int rsize;
+ int (*size)(dev_t);
+ int rsize;
- if ((major(dev) < nblkdev) && (size = bdevsw[major(dev)].d_psize)) {
- rsize = (*size)(dev);
- if (rsize <= 0) /* did size fail? */
- vp->v_specsize = DEV_BSIZE;
- else
- vp->v_specsize = rsize;
- }
- else
- vp->v_specsize = DEV_BSIZE;
+ if ((major(dev) < nblkdev) && (size = bdevsw[major(dev)].d_psize)) {
+ rsize = (*size)(dev);
+ if (rsize <= 0) { /* did size fail? */
+ vp->v_specsize = DEV_BSIZE;
+ } else {
+ vp->v_specsize = rsize;
+ }
+ } else {
+ vp->v_specsize = DEV_BSIZE;
+ }
}
void
set_fsblocksize(struct vnode *vp)
{
-
if (vp->v_type == VBLK) {
dev_t dev = (dev_t)vp->v_rdev;
int maj = major(dev);
- if ((u_int)maj >= (u_int)nblkdev)
+ if ((u_int)maj >= (u_int)nblkdev) {
return;
+ }
vnode_lock(vp);
set_blocksize(vp, dev);
vnode_unlock(vp);
}
-
}
@@ -195,12 +293,7 @@ set_fsblocksize(struct vnode *vp)
* Open a special file.
*/
int
-spec_open(ap)
- struct vnop_open_args /* {
- struct vnode *a_vp;
- int a_mode;
- vfs_context_t a_context;
- } */ *ap;
+spec_open(struct vnop_open_args *ap)
{
struct proc *p = vfs_context_proc(ap->a_context);
kauth_cred_t cred = vfs_context_ucred(ap->a_context);
@@ -212,166 +305,266 @@ spec_open(ap)
/*
* Don't allow open if fs is mounted -nodev.
*/
- if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV))
- return (ENXIO);
+ if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) {
+ return ENXIO;
+ }
switch (vp->v_type) {
-
case VCHR:
- if ((u_int)maj >= (u_int)nchrdev)
- return (ENXIO);
+ if ((u_int)maj >= (u_int)nchrdev) {
+ return ENXIO;
+ }
if (cred != FSCRED && (ap->a_mode & FWRITE)) {
+#if 0
/*
* When running in very secure mode, do not allow
* opens for writing of any disk character devices.
*/
- if (securelevel >= 2 && isdisk(dev, VCHR))
- return (EPERM);
+ if (securelevel >= 2 && isdisk(dev, VCHR)) {
+ return EPERM;
+ }
+#endif
+
+ /* Never allow writing to /dev/mem or /dev/kmem */
+ if (iskmemdev(dev)) {
+ return EPERM;
+ }
/*
- * When running in secure mode, do not allow opens
- * for writing of /dev/mem, /dev/kmem, or character
- * devices whose corresponding block devices are
- * currently mounted.
+ * When running in secure mode, do not allow opens for
+ * writing of character devices whose corresponding block
+ * devices are currently mounted.
*/
if (securelevel >= 1) {
- if ((bdev = chrtoblk(dev)) != NODEV && check_mountedon(bdev, VBLK, &error))
- return (error);
- if (iskmemdev(dev))
- return (EPERM);
+ if ((bdev = chrtoblk(dev)) != NODEV && check_mountedon(bdev, VBLK, &error)) {
+ return error;
+ }
}
}
- if (cdevsw[maj].d_type == D_TTY) {
- vnode_lock(vp);
- vp->v_flag |= VISTTY;
- vnode_unlock(vp);
- }
+
+ devsw_lock(dev, S_IFCHR);
error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, p);
- return (error);
+
+ if (error == 0) {
+ vp->v_specinfo->si_opencount++;
+ }
+
+ devsw_unlock(dev, S_IFCHR);
+
+ if (error == 0 && cdevsw[maj].d_type == D_DISK && !vp->v_un.vu_specinfo->si_initted) {
+ int isssd = 0;
+ uint64_t throttle_mask = 0;
+ uint32_t devbsdunit = 0;
+
+ if (VNOP_IOCTL(vp, DKIOCGETTHROTTLEMASK, (caddr_t)&throttle_mask, 0, NULL) == 0) {
+ if (throttle_mask != 0 &&
+ VNOP_IOCTL(vp, DKIOCISSOLIDSTATE, (caddr_t)&isssd, 0, ap->a_context) == 0) {
+ /*
+ * as a reasonable approximation, only use the lowest bit of the mask
+ * to generate a disk unit number
+ */
+ devbsdunit = num_trailing_0(throttle_mask);
+
+ vnode_lock(vp);
+
+ vp->v_un.vu_specinfo->si_isssd = isssd;
+ vp->v_un.vu_specinfo->si_devbsdunit = devbsdunit;
+ vp->v_un.vu_specinfo->si_throttle_mask = throttle_mask;
+ vp->v_un.vu_specinfo->si_throttleable = 1;
+ vp->v_un.vu_specinfo->si_initted = 1;
+
+ vnode_unlock(vp);
+ }
+ }
+ if (vp->v_un.vu_specinfo->si_initted == 0) {
+ vnode_lock(vp);
+ vp->v_un.vu_specinfo->si_initted = 1;
+ vnode_unlock(vp);
+ }
+ }
+ return error;
case VBLK:
- if ((u_int)maj >= (u_int)nblkdev)
- return (ENXIO);
+ if ((u_int)maj >= (u_int)nblkdev) {
+ return ENXIO;
+ }
/*
* When running in very secure mode, do not allow
* opens for writing of any disk block devices.
*/
if (securelevel >= 2 && cred != FSCRED &&
- (ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK)
- return (EPERM);
+ (ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK) {
+ return EPERM;
+ }
/*
* Do not allow opens of block devices that are
* currently mounted.
*/
- if ( (error = vfs_mountedon(vp)) )
- return (error);
+ if ((error = vfs_mountedon(vp))) {
+ return error;
+ }
+
+ devsw_lock(dev, S_IFBLK);
error = (*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, p);
if (!error) {
- u_int64_t blkcnt;
- u_int32_t blksize;
+ vp->v_specinfo->si_opencount++;
+ }
+ devsw_unlock(dev, S_IFBLK);
+
+ if (!error) {
+ u_int64_t blkcnt;
+ u_int32_t blksize;
int setsize = 0;
u_int32_t size512 = 512;
- if (!VNOP_IOCTL(vp, DKIOCGETBLOCKSIZE, (caddr_t)&blksize, 0, ap->a_context)) {
+ if (!VNOP_IOCTL(vp, DKIOCGETBLOCKSIZE, (caddr_t)&blksize, 0, ap->a_context)) {
/* Switch to 512 byte sectors (temporarily) */
if (!VNOP_IOCTL(vp, DKIOCSETBLOCKSIZE, (caddr_t)&size512, FWRITE, ap->a_context)) {
- /* Get the number of 512 byte physical blocks. */
- if (!VNOP_IOCTL(vp, DKIOCGETBLOCKCOUNT, (caddr_t)&blkcnt, 0, ap->a_context)) {
+ /* Get the number of 512 byte physical blocks. */
+ if (!VNOP_IOCTL(vp, DKIOCGETBLOCKCOUNT, (caddr_t)&blkcnt, 0, ap->a_context)) {
setsize = 1;
- }
+ }
}
/* If it doesn't set back, we can't recover */
- if (VNOP_IOCTL(vp, DKIOCSETBLOCKSIZE, (caddr_t)&blksize, FWRITE, ap->a_context))
- error = ENXIO;
- }
+ if (VNOP_IOCTL(vp, DKIOCSETBLOCKSIZE, (caddr_t)&blksize, FWRITE, ap->a_context)) {
+ error = ENXIO;
+ }
+ }
vnode_lock(vp);
- set_blocksize(vp, dev);
+ set_blocksize(vp, dev);
- /*
- * Cache the size in bytes of the block device for later
- * use by spec_write().
- */
- if (setsize)
+ /*
+ * Cache the size in bytes of the block device for later
+ * use by spec_write().
+ */
+ if (setsize) {
vp->v_specdevsize = blkcnt * (u_int64_t)size512;
- else
- vp->v_specdevsize = (u_int64_t)0; /* Default: Can't get */
-
+ } else {
+ vp->v_specdevsize = (u_int64_t)0; /* Default: Can't get */
+ }
vnode_unlock(vp);
-
}
- return(error);
+ return error;
default:
- panic("spec_open type");
+ panic("spec_open type");
}
- return (0);
+ return 0;
}
/*
* Vnode op for read
*/
int
-spec_read(ap)
- struct vnop_read_args /* {
- struct vnode *a_vp;
- struct uio *a_uio;
- int a_ioflag;
- vfs_context_t a_context;
- } */ *ap;
-{
- register struct vnode *vp = ap->a_vp;
- register struct uio *uio = ap->a_uio;
+spec_read(struct vnop_read_args *ap)
+{
+ struct vnode *vp = ap->a_vp;
+ struct uio *uio = ap->a_uio;
struct buf *bp;
daddr64_t bn, nextbn;
long bsize, bscale;
- int devBlockSize=0;
+ int devBlockSize = 0;
int n, on;
int error = 0;
dev_t dev;
#if DIAGNOSTIC
- if (uio->uio_rw != UIO_READ)
+ if (uio->uio_rw != UIO_READ) {
panic("spec_read mode");
- if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg))
+ }
+ if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) {
panic("spec_read proc");
+ }
#endif
- if (uio_resid(uio) == 0)
- return (0);
+ if (uio_resid(uio) == 0) {
+ return 0;
+ }
switch (vp->v_type) {
-
case VCHR:
+ {
+ struct _throttle_io_info_t *throttle_info = NULL;
+ int thread_throttle_level;
+ uint64_t blkno = 0;
+ uint32_t iolen = 0;
+ int ddisk = 0;
+ int ktrace_code = DKIO_READ;
+ devBlockSize = vp->v_specsize;
+ uintptr_t our_id;
+
+ if (cdevsw[major(vp->v_rdev)].d_type == D_DISK) {
+ ddisk = 1;
+ }
+
+ if (ddisk && vp->v_un.vu_specinfo->si_throttleable) {
+ throttle_info = &_throttle_io_info[vp->v_un.vu_specinfo->si_devbsdunit];
+ thread_throttle_level = throttle_info_update_internal(throttle_info, NULL, 0, vp->v_un.vu_specinfo->si_isssd, TRUE, NULL);
+ }
+
+ if (kdebug_enable && ddisk) {
+ if (devBlockSize == 0) {
+ devBlockSize = 512; // default sector size
+ }
+
+ if (uio_offset(uio) && devBlockSize) {
+ blkno = ((uint64_t) uio_offset(uio) / ((uint64_t)devBlockSize));
+ }
+ iolen = (int) uio_resid(uio);
+ our_id = (uintptr_t)thread_tid(current_thread());
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON,
+ (FSDBG_CODE(DBG_DKRW, ktrace_code)) | DBG_FUNC_NONE, our_id,
+ vp->v_rdev, blkno, iolen, 0);
+ }
+
error = (*cdevsw[major(vp->v_rdev)].d_read)
- (vp->v_rdev, uio, ap->a_ioflag);
- return (error);
+ (vp->v_rdev, uio, ap->a_ioflag);
+
+
+ if (kdebug_enable && ddisk) {
+ uint32_t residual = (uint32_t)uio_resid(uio);
+ ktrace_code |= DKIO_DONE;
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON,
+ (FSDBG_CODE(DBG_DKRW, ktrace_code)) | DBG_FUNC_NONE, our_id,
+ (uintptr_t)VM_KERNEL_ADDRPERM(vp), residual, error, 0);
+ }
+
+ if (throttle_info) {
+ throttle_info_end_io_internal(throttle_info, thread_throttle_level);
+ }
+
+ return error;
+ }
case VBLK:
- if (uio->uio_offset < 0)
- return (EINVAL);
+ if (uio->uio_offset < 0) {
+ return EINVAL;
+ }
dev = vp->v_rdev;
devBlockSize = vp->v_specsize;
- if (devBlockSize > PAGE_SIZE)
- return (EINVAL);
+ if (devBlockSize > PAGE_SIZE) {
+ return EINVAL;
+ }
- bscale = PAGE_SIZE / devBlockSize;
+ bscale = PAGE_SIZE / devBlockSize;
bsize = bscale * devBlockSize;
do {
on = uio->uio_offset % bsize;
- bn = (daddr64_t)((uio->uio_offset / devBlockSize) &~ (bscale - 1));
-
+ bn = (daddr64_t)((uio->uio_offset / devBlockSize) & ~(bscale - 1));
+
if (vp->v_speclastr + bscale == bn) {
- nextbn = bn + bscale;
+ nextbn = bn + bscale;
error = buf_breadn(vp, bn, (int)bsize, &nextbn,
- (int *)&bsize, 1, NOCRED, &bp);
- } else
- error = buf_bread(vp, bn, (int)bsize, NOCRED, &bp);
+ (int *)&bsize, 1, NOCRED, &bp);
+ } else {
+ error = buf_bread(vp, bn, (int)bsize, NOCRED, &bp);
+ }
vnode_lock(vp);
vp->v_speclastr = bn;
@@ -379,93 +572,139 @@ spec_read(ap)
n = bsize - buf_resid(bp);
if ((on > n) || error) {
- if (!error)
- error = EINVAL;
+ if (!error) {
+ error = EINVAL;
+ }
buf_brelse(bp);
- return (error);
+ return error;
}
- // LP64todo - fix this!
n = min((unsigned)(n - on), uio_resid(uio));
error = uiomove((char *)buf_dataptr(bp) + on, n, uio);
- if (n + on == bsize)
+ if (n + on == bsize) {
buf_markaged(bp);
+ }
buf_brelse(bp);
} while (error == 0 && uio_resid(uio) > 0 && n != 0);
- return (error);
+ return error;
default:
panic("spec_read type");
}
/* NOTREACHED */
- return (0);
+ return 0;
}
/*
* Vnode op for write
*/
int
-spec_write(ap)
- struct vnop_write_args /* {
- struct vnode *a_vp;
- struct uio *a_uio;
- int a_ioflag;
- vfs_context_t a_context;
- } */ *ap;
-{
- register struct vnode *vp = ap->a_vp;
- register struct uio *uio = ap->a_uio;
+spec_write(struct vnop_write_args *ap)
+{
+ struct vnode *vp = ap->a_vp;
+ struct uio *uio = ap->a_uio;
struct buf *bp;
daddr64_t bn;
int bsize, blkmask, bscale;
- register int io_sync;
- register int io_size;
- int devBlockSize=0;
- register int n, on;
+ int io_sync;
+ int devBlockSize = 0;
+ int n, on;
int error = 0;
dev_t dev;
#if DIAGNOSTIC
- if (uio->uio_rw != UIO_WRITE)
+ if (uio->uio_rw != UIO_WRITE) {
panic("spec_write mode");
- if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg))
+ }
+ if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) {
panic("spec_write proc");
+ }
#endif
switch (vp->v_type) {
-
case VCHR:
+ {
+ struct _throttle_io_info_t *throttle_info = NULL;
+ int thread_throttle_level;
+ dev = vp->v_rdev;
+ devBlockSize = vp->v_specsize;
+ uint32_t iolen = 0;
+ uint64_t blkno = 0;
+ int ddisk = 0;
+ int ktrace_code = 0; // write is implied; read must be OR'd in.
+ uintptr_t our_id;
+
+ if (cdevsw[major(dev)].d_type == D_DISK) {
+ ddisk = 1;
+ }
+
+ if (ddisk && vp->v_un.vu_specinfo->si_throttleable) {
+ throttle_info = &_throttle_io_info[vp->v_un.vu_specinfo->si_devbsdunit];
+
+ thread_throttle_level = throttle_info_update_internal(throttle_info, NULL, 0, vp->v_un.vu_specinfo->si_isssd, TRUE, NULL);
+
+ microuptime(&throttle_info->throttle_last_write_timestamp);
+ }
+
+ if (kdebug_enable && ddisk) {
+ if (devBlockSize == 0) {
+ devBlockSize = 512; // default sector size
+ }
+ if ((uio_offset(uio) != 0) && devBlockSize) {
+ blkno = ((uint64_t)uio_offset(uio)) / ((uint64_t)devBlockSize);
+ }
+ iolen = (int)uio_resid(uio);
+ our_id = (uintptr_t)thread_tid(current_thread());
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON,
+ (FSDBG_CODE(DBG_DKRW, ktrace_code)) | DBG_FUNC_NONE, our_id,
+ vp->v_rdev, blkno, iolen, 0);
+ }
error = (*cdevsw[major(vp->v_rdev)].d_write)
- (vp->v_rdev, uio, ap->a_ioflag);
- return (error);
+ (vp->v_rdev, uio, ap->a_ioflag);
+
+ if (kdebug_enable && ddisk) {
+ //emit the I/O completion
+ uint32_t residual = (uint32_t)uio_resid(uio);
+ ktrace_code |= DKIO_DONE;
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON,
+ (FSDBG_CODE(DBG_DKRW, ktrace_code)) | DBG_FUNC_NONE, our_id,
+ (uintptr_t)VM_KERNEL_ADDRPERM(vp), residual, error, 0);
+ }
+
+ if (throttle_info) {
+ throttle_info_end_io_internal(throttle_info, thread_throttle_level);
+ }
+
+ return error;
+ }
case VBLK:
- if (uio_resid(uio) == 0)
- return (0);
- if (uio->uio_offset < 0)
- return (EINVAL);
+ if (uio_resid(uio) == 0) {
+ return 0;
+ }
+ if (uio->uio_offset < 0) {
+ return EINVAL;
+ }
io_sync = (ap->a_ioflag & IO_SYNC);
- // LP64todo - fix this!
- io_size = uio_resid(uio);
dev = (vp->v_rdev);
devBlockSize = vp->v_specsize;
- if (devBlockSize > PAGE_SIZE)
- return(EINVAL);
+ if (devBlockSize > PAGE_SIZE) {
+ return EINVAL;
+ }
- bscale = PAGE_SIZE / devBlockSize;
+ bscale = PAGE_SIZE / devBlockSize;
blkmask = bscale - 1;
bsize = bscale * devBlockSize;
-
+
do {
- bn = (daddr64_t)((uio->uio_offset / devBlockSize) &~ blkmask);
+ bn = (daddr64_t)((uio->uio_offset / devBlockSize) & ~blkmask);
on = uio->uio_offset % bsize;
- // LP64todo - fix this!
n = min((unsigned)(bsize - on), uio_resid(uio));
/*
@@ -481,106 +720,98 @@ spec_write(ap)
if (n == bsize &&
vp->v_specdevsize != (u_int64_t)0 &&
(uio->uio_offset + (u_int64_t)n) > vp->v_specdevsize) {
- /* reduce the size of the read to what is there */
- n = (uio->uio_offset + (u_int64_t)n) - vp->v_specdevsize;
+ /* reduce the size of the read to what is there */
+ n = (uio->uio_offset + (u_int64_t)n) - vp->v_specdevsize;
}
- if (n == bsize)
- bp = buf_getblk(vp, bn, bsize, 0, 0, BLK_WRITE);
- else
- error = (int)buf_bread(vp, bn, bsize, NOCRED, &bp);
+ if (n == bsize) {
+ bp = buf_getblk(vp, bn, bsize, 0, 0, BLK_WRITE);
+ } else {
+ error = (int)buf_bread(vp, bn, bsize, NOCRED, &bp);
+ }
/* Translate downstream error for upstream, if needed */
- if (!error)
+ if (!error) {
error = (int)buf_error(bp);
+ }
if (error) {
buf_brelse(bp);
- return (error);
+ return error;
}
n = min(n, bsize - buf_resid(bp));
error = uiomove((char *)buf_dataptr(bp) + on, n, uio);
if (error) {
buf_brelse(bp);
- return (error);
+ return error;
}
buf_markaged(bp);
- if (io_sync)
- error = buf_bwrite(bp);
- else {
- if ((n + on) == bsize)
- error = buf_bawrite(bp);
- else
- error = buf_bdwrite(bp);
+ if (io_sync) {
+ error = buf_bwrite(bp);
+ } else {
+ if ((n + on) == bsize) {
+ error = buf_bawrite(bp);
+ } else {
+ error = buf_bdwrite(bp);
+ }
}
} while (error == 0 && uio_resid(uio) > 0 && n != 0);
- return (error);
+ return error;
default:
panic("spec_write type");
}
/* NOTREACHED */
- return (0);
+ return 0;
}
/*
* Device ioctl operation.
*/
int
-spec_ioctl(ap)
- struct vnop_ioctl_args /* {
- struct vnode *a_vp;
- int a_command;
- caddr_t a_data;
- int a_fflag;
- vfs_context_t a_context;
- } */ *ap;
+spec_ioctl(struct vnop_ioctl_args *ap)
{
proc_t p = vfs_context_proc(ap->a_context);
dev_t dev = ap->a_vp->v_rdev;
+ int retval = 0;
- switch (ap->a_vp->v_type) {
+ KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_IOCTL, 0) | DBG_FUNC_START,
+ dev, ap->a_command, ap->a_fflag, ap->a_vp->v_type, 0);
+ switch (ap->a_vp->v_type) {
case VCHR:
- return ((*cdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data,
- ap->a_fflag, p));
+ retval = (*cdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data,
+ ap->a_fflag, p);
+ break;
case VBLK:
- if (ap->a_command == 0 && (int)ap->a_data == B_TAPE) {
- if (bdevsw[major(dev)].d_type == D_TAPE)
- return (0);
- else
- return (1);
+ retval = (*bdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, ap->a_fflag, p);
+ if (!retval && ap->a_command == DKIOCSETBLOCKSIZE) {
+ ap->a_vp->v_specsize = *(uint32_t *)ap->a_data;
}
- return ((*bdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data,
- ap->a_fflag, p));
+ break;
default:
panic("spec_ioctl");
/* NOTREACHED */
}
- return (0);
+ KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_IOCTL, 0) | DBG_FUNC_END,
+ dev, ap->a_command, ap->a_fflag, retval, 0);
+
+ return retval;
}
int
-spec_select(ap)
- struct vnop_select_args /* {
- struct vnode *a_vp;
- int a_which;
- int a_fflags;
- void * a_wql;
- vfs_context_t a_context;
- } */ *ap;
+spec_select(struct vnop_select_args *ap)
{
proc_t p = vfs_context_proc(ap->a_context);
- register dev_t dev;
+ dev_t dev;
switch (ap->a_vp->v_type) {
-
default:
- return (1); /* XXX */
+ return 1; /* XXX */
case VCHR:
dev = ap->a_vp->v_rdev;
@@ -588,346 +819,2344 @@ spec_select(ap)
}
}
+static int filt_specattach(struct knote *kn, struct kevent_qos_s *kev);
+
+int
+spec_kqfilter(vnode_t vp, struct knote *kn, struct kevent_qos_s *kev)
+{
+ dev_t dev;
+
+ assert(vnode_ischr(vp));
+
+ dev = vnode_specrdev(vp);
+
+#if NETWORKING
+ /*
+ * Try a bpf device, as defined in bsd/net/bpf.c
+ * If it doesn't error out the attach, then it
+ * claimed it. Otherwise, fall through and try
+ * other attaches.
+ */
+ int32_t tmp_flags = kn->kn_flags;
+ int64_t tmp_sdata = kn->kn_sdata;
+ int res;
+
+ res = bpfkqfilter(dev, kn);
+ if ((kn->kn_flags & EV_ERROR) == 0) {
+ return res;
+ }
+ kn->kn_flags = tmp_flags;
+ kn->kn_sdata = tmp_sdata;
+#endif
+
+ if (major(dev) > nchrdev) {
+ knote_set_error(kn, ENXIO);
+ return 0;
+ }
+
+ kn->kn_vnode_kqok = !!(cdevsw_flags[major(dev)] & CDEVSW_SELECT_KQUEUE);
+ kn->kn_vnode_use_ofst = !!(cdevsw_flags[major(dev)] & CDEVSW_USE_OFFSET);
+
+ if (cdevsw_flags[major(dev)] & CDEVSW_IS_PTS) {
+ kn->kn_filtid = EVFILTID_PTSD;
+ return ptsd_kqfilter(dev, kn);
+ } else if (cdevsw_flags[major(dev)] & CDEVSW_IS_PTC) {
+ kn->kn_filtid = EVFILTID_PTMX;
+ return ptmx_kqfilter(dev, kn);
+ } else if (cdevsw[major(dev)].d_type == D_TTY && kn->kn_vnode_kqok) {
+ /*
+ * TTYs from drivers that use struct ttys use their own filter
+ * routines. The PTC driver doesn't use the tty for character
+ * counts, so it must go through the select fallback.
+ */
+ kn->kn_filtid = EVFILTID_TTY;
+ return knote_fops(kn)->f_attach(kn, kev);
+ }
+
+ /* Try to attach to other char special devices */
+ return filt_specattach(kn, kev);
+}
+
/*
* Synch buffers associated with a block device
*/
int
spec_fsync_internal(vnode_t vp, int waitfor, __unused vfs_context_t context)
{
- if (vp->v_type == VCHR)
- return (0);
+ if (vp->v_type == VCHR) {
+ return 0;
+ }
/*
* Flush all dirty buffers associated with a block device.
*/
- buf_flushdirtyblks(vp, waitfor == MNT_WAIT, 0, (char *)"spec_fsync");
+ buf_flushdirtyblks(vp, (waitfor == MNT_WAIT || waitfor == MNT_DWAIT), 0, "spec_fsync");
- return (0);
+ return 0;
}
int
-spec_fsync(ap)
- struct vnop_fsync_args /* {
- struct vnode *a_vp;
- int a_waitfor;
- vfs_context_t a_context;
- } */ *ap;
+spec_fsync(struct vnop_fsync_args *ap)
{
return spec_fsync_internal(ap->a_vp, ap->a_waitfor, ap->a_context);
}
+
/*
* Just call the device strategy routine
*/
-extern int hard_throttle_on_root;
+void throttle_init(void);
-#define LOWPRI_DELAY_MSECS 200
-#define LOWPRI_WINDOW_MSECS 200
+#if 0
+#define DEBUG_ALLOC_THROTTLE_INFO(format, debug_info, args...) \
+ do { \
+ if ((debug_info)->alloc) \
+ printf("%s: "format, __FUNCTION__, ## args); \
+ } while(0)
-int lowpri_IO_window_msecs = LOWPRI_WINDOW_MSECS;
-int lowpri_IO_delay_msecs = LOWPRI_DELAY_MSECS;
+#else
+#define DEBUG_ALLOC_THROTTLE_INFO(format, debug_info, args...)
+#endif
-struct timeval last_normal_IO_timestamp;
-struct timeval last_lowpri_IO_timestamp;
-struct timeval lowpri_IO_window = { 0, LOWPRI_WINDOW_MSECS * 1000 };
-int
-spec_strategy(ap)
- struct vnop_strategy_args /* {
- struct buf *a_bp;
- } */ *ap;
-{
- buf_t bp;
- int bflags;
- dev_t bdev;
- proc_t p;
- struct timeval elapsed;
-
- bp = ap->a_bp;
- bdev = buf_device(bp);
- bflags = buf_flags(bp);
-
- if (kdebug_enable) {
- int code = 0;
-
- if (bflags & B_READ)
- code |= DKIO_READ;
- if (bflags & B_ASYNC)
- code |= DKIO_ASYNC;
-
- if (bflags & B_META)
- code |= DKIO_META;
- else if (bflags & B_PAGEIO)
- code |= DKIO_PAGING;
-
- KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_DKRW, code) | DBG_FUNC_NONE,
- (unsigned int)bp, bdev, (int)buf_blkno(bp), buf_count(bp), 0);
- }
- if (((bflags & (B_PAGEIO | B_READ)) == (B_PAGEIO | B_READ)) &&
- (buf_vnode(bp)->v_mount->mnt_kern_flag & MNTK_ROOTDEV))
- hard_throttle_on_root = 1;
-
- if ( lowpri_IO_delay_msecs && lowpri_IO_window_msecs ) {
- p = current_proc();
-
- if ( (p == NULL) || !(p->p_lflag & P_LLOW_PRI_IO)) {
- if (!(p->p_lflag & P_LBACKGROUND_IO))
- microuptime(&last_normal_IO_timestamp);
- } else {
- microuptime(&last_lowpri_IO_timestamp);
+SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier1_window_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_windows_msecs[THROTTLE_LEVEL_TIER1], 0, "");
+SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier2_window_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_windows_msecs[THROTTLE_LEVEL_TIER2], 0, "");
+SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier3_window_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_windows_msecs[THROTTLE_LEVEL_TIER3], 0, "");
- elapsed = last_lowpri_IO_timestamp;
- timevalsub(&elapsed, &last_normal_IO_timestamp);
+SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier1_io_period_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_msecs[THROTTLE_LEVEL_TIER1], 0, "");
+SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier2_io_period_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_msecs[THROTTLE_LEVEL_TIER2], 0, "");
+SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier3_io_period_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_msecs[THROTTLE_LEVEL_TIER3], 0, "");
- lowpri_IO_window.tv_sec = lowpri_IO_window_msecs / 1000;
- lowpri_IO_window.tv_usec = (lowpri_IO_window_msecs % 1000) * 1000;
+SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier1_io_period_ssd_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_ssd_msecs[THROTTLE_LEVEL_TIER1], 0, "");
+SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier2_io_period_ssd_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_ssd_msecs[THROTTLE_LEVEL_TIER2], 0, "");
+SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_tier3_io_period_ssd_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_io_period_ssd_msecs[THROTTLE_LEVEL_TIER3], 0, "");
- if (timevalcmp(&elapsed, &lowpri_IO_window, <)) {
- struct uthread *ut;
+SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_enabled, CTLFLAG_RW | CTLFLAG_LOCKED, &lowpri_throttle_enabled, 0, "");
- /*
- * I'd really like to do the IOSleep here, but
- * we may be holding all kinds of filesystem related locks
- * and the pages for this I/O marked 'busy'...
- * we don't want to cause a normal task to block on
- * one of these locks while we're throttling a task marked
- * for low priority I/O... we'll mark the uthread and
- * do the delay just before we return from the system
- * call that triggered this I/O or from vnode_pagein
- */
- ut = get_bsdthread_info(current_thread());
- ut->uu_lowpri_delay = lowpri_IO_delay_msecs;
- }
- }
- }
- (*bdevsw[major(bdev)].d_strategy)(bp);
- return (0);
-}
+static lck_grp_t *throttle_lock_grp;
+static lck_attr_t *throttle_lock_attr;
+static lck_grp_attr_t *throttle_lock_grp_attr;
/*
- * This is a noop, simply returning what one has been given.
+ * throttled I/O helper function
+ * convert the index of the lowest set bit to a device index
*/
int
-spec_blockmap(__unused struct vnop_blockmap_args *ap)
+num_trailing_0(uint64_t n)
{
- return (ENOTSUP);
+ /*
+ * since in most cases the number of trailing 0s is very small,
+ * we simply counting sequentially from the lowest bit
+ */
+ if (n == 0) {
+ return sizeof(n) * 8;
+ }
+ int count = 0;
+ while (!ISSET(n, 1)) {
+ n >>= 1;
+ ++count;
+ }
+ return count;
}
/*
- * Device close routine
+ * Release the reference and if the item was allocated and this is the last
+ * reference then free it.
+ *
+ * This routine always returns the old value.
*/
-int
-spec_close(ap)
- struct vnop_close_args /* {
- struct vnode *a_vp;
- int a_fflag;
- vfs_context_t a_context;
- } */ *ap;
-{
- register struct vnode *vp = ap->a_vp;
- dev_t dev = vp->v_rdev;
- int (*devclose)(dev_t, int, int, struct proc *);
- int mode, error;
- struct proc *p = vfs_context_proc(ap->a_context);
-
- switch (vp->v_type) {
-
- case VCHR:
- /*
- * Hack: a tty device that is a controlling terminal
- * has a reference from the session structure.
- * We cannot easily tell that a character device is
- * a controlling terminal, unless it is the closing
- * process' controlling terminal. In that case,
- * if the reference count is 2 (this last descriptor
- * plus the session), release the reference from the session.
- */
- if (vcount(vp) == 2 && p &&
- vp == p->p_session->s_ttyvp) {
- p->p_session->s_ttyvp = NULL;
- vnode_rele(vp);
- }
- /*
- * close on last reference.
- */
- if (vcount(vp) > 1)
- return (0);
- devclose = cdevsw[major(dev)].d_close;
- mode = S_IFCHR;
- break;
-
- case VBLK:
-#ifdef DEVFS_IMPLEMENTS_LOCKING
- /*
- * On last close of a block device (that isn't mounted)
- * we must invalidate any in core blocks, so that
- * we can, for instance, change floppy disks.
- */
- if ((error = spec_fsync_internal(vp, MNT_WAIT, ap->a_context)))
- return (error);
+static int
+throttle_info_rel(struct _throttle_io_info_t *info)
+{
+ SInt32 oldValue = OSDecrementAtomic(&info->throttle_refcnt);
- error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0);
- if (error)
- return (error);
- /*
- * Since every use (buffer, vnode, swap, blockmap)
- * holds a reference to the vnode, and because we mark
- * any other vnodes that alias this device, when the
- * sum of the reference counts on all the aliased
- * vnodes descends to one, we are on last close.
- */
- if (vcount(vp) > 1)
- return (0);
-#else /* DEVFS_IMPLEMENTS_LOCKING */
- /*
- * Since every use (buffer, vnode, swap, blockmap)
- * holds a reference to the vnode, and because we mark
- * any other vnodes that alias this device, when the
- * sum of the reference counts on all the aliased
- * vnodes descends to one, we are on last close.
- */
- if (vcount(vp) > 1)
- return (0);
+ DEBUG_ALLOC_THROTTLE_INFO("refcnt = %d info = %p\n",
+ info, (int)(oldValue - 1), info );
- /*
- * On last close of a block device (that isn't mounted)
- * we must invalidate any in core blocks, so that
- * we can, for instance, change floppy disks.
- */
- if ((error = spec_fsync_internal(vp, MNT_WAIT, ap->a_context)))
- return (error);
+ /* The reference count just went negative, very bad */
+ if (oldValue == 0) {
+ panic("throttle info ref cnt went negative!");
+ }
- error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0);
- if (error)
- return (error);
-#endif /* DEVFS_IMPLEMENTS_LOCKING */
- devclose = bdevsw[major(dev)].d_close;
- mode = S_IFBLK;
- break;
+ /*
+ * Once reference count is zero, no one else should be able to take a
+ * reference
+ */
+ if ((info->throttle_refcnt == 0) && (info->throttle_alloc)) {
+ DEBUG_ALLOC_THROTTLE_INFO("Freeing info = %p\n", info);
- default:
- panic("spec_close: not special");
+ lck_mtx_destroy(&info->throttle_lock, throttle_lock_grp);
+ FREE(info, M_TEMP);
}
-
- return ((*devclose)(dev, ap->a_fflag, mode, p));
+ return oldValue;
}
+
/*
- * Return POSIX pathconf information applicable to special devices.
+ * Just take a reference on the throttle info structure.
+ *
+ * This routine always returns the old value.
*/
-int
-spec_pathconf(ap)
- struct vnop_pathconf_args /* {
- struct vnode *a_vp;
- int a_name;
- int *a_retval;
- vfs_context_t a_context;
- } */ *ap;
+static SInt32
+throttle_info_ref(struct _throttle_io_info_t *info)
{
+ SInt32 oldValue = OSIncrementAtomic(&info->throttle_refcnt);
- switch (ap->a_name) {
- case _PC_LINK_MAX:
- *ap->a_retval = LINK_MAX;
- return (0);
- case _PC_MAX_CANON:
- *ap->a_retval = MAX_CANON;
- return (0);
- case _PC_MAX_INPUT:
- *ap->a_retval = MAX_INPUT;
- return (0);
- case _PC_PIPE_BUF:
- *ap->a_retval = PIPE_BUF;
- return (0);
- case _PC_CHOWN_RESTRICTED:
- *ap->a_retval = 1;
- return (0);
- case _PC_VDISABLE:
- *ap->a_retval = _POSIX_VDISABLE;
- return (0);
- default:
- return (EINVAL);
+ DEBUG_ALLOC_THROTTLE_INFO("refcnt = %d info = %p\n",
+ info, (int)(oldValue - 1), info );
+ /* Allocated items should never have a reference of zero */
+ if (info->throttle_alloc && (oldValue == 0)) {
+ panic("Taking a reference without calling create throttle info!\n");
}
- /* NOTREACHED */
+
+ return oldValue;
}
/*
- * Special device failed operation
+ * on entry the throttle_lock is held...
+ * this function is responsible for taking
+ * and dropping the reference on the info
+ * structure which will keep it from going
+ * away while the timer is running if it
+ * happens to have been dynamically allocated by
+ * a network fileystem kext which is now trying
+ * to free it
*/
-int
-spec_ebadf(__unused void *dummy)
+static uint32_t
+throttle_timer_start(struct _throttle_io_info_t *info, boolean_t update_io_count, int wakelevel)
{
+ struct timeval elapsed;
+ struct timeval now;
+ struct timeval period;
+ uint64_t elapsed_msecs;
+ int throttle_level;
+ int level;
+ int msecs;
+ boolean_t throttled = FALSE;
+ boolean_t need_timer = FALSE;
+
+ microuptime(&now);
+
+ if (update_io_count == TRUE) {
+ info->throttle_io_count_begin = info->throttle_io_count;
+ info->throttle_io_period_num++;
+
+ while (wakelevel >= THROTTLE_LEVEL_THROTTLED) {
+ info->throttle_start_IO_period_timestamp[wakelevel--] = now;
+ }
- return (EBADF);
-}
+ info->throttle_min_timer_deadline = now;
-/*
- * Special device bad operation
- */
-int
-spec_badop()
-{
+ msecs = info->throttle_io_periods[THROTTLE_LEVEL_THROTTLED];
+ period.tv_sec = msecs / 1000;
+ period.tv_usec = (msecs % 1000) * 1000;
- panic("spec_badop called");
- /* NOTREACHED */
+ timevaladd(&info->throttle_min_timer_deadline, &period);
+ }
+ for (throttle_level = THROTTLE_LEVEL_START; throttle_level < THROTTLE_LEVEL_END; throttle_level++) {
+ elapsed = now;
+ timevalsub(&elapsed, &info->throttle_window_start_timestamp[throttle_level]);
+ elapsed_msecs = (uint64_t)elapsed.tv_sec * (uint64_t)1000 + (elapsed.tv_usec / 1000);
+
+ for (level = throttle_level + 1; level <= THROTTLE_LEVEL_END; level++) {
+ if (!TAILQ_EMPTY(&info->throttle_uthlist[level])) {
+ if (elapsed_msecs < (uint64_t)throttle_windows_msecs[level] || info->throttle_inflight_count[throttle_level]) {
+ /*
+ * we had an I/O occur at a higher priority tier within
+ * this tier's throttle window
+ */
+ throttled = TRUE;
+ }
+ /*
+ * we assume that the windows are the same or longer
+ * as we drop through the throttling tiers... thus
+ * we can stop looking once we run into a tier with
+ * threads to schedule regardless of whether it's
+ * still in its throttling window or not
+ */
+ break;
+ }
+ }
+ if (throttled == TRUE) {
+ break;
+ }
+ }
+ if (throttled == TRUE) {
+ uint64_t deadline = 0;
+ struct timeval target;
+ struct timeval min_target;
+
+ /*
+ * we've got at least one tier still in a throttled window
+ * so we need a timer running... compute the next deadline
+ * and schedule it
+ */
+ for (level = throttle_level + 1; level <= THROTTLE_LEVEL_END; level++) {
+ if (TAILQ_EMPTY(&info->throttle_uthlist[level])) {
+ continue;
+ }
+
+ target = info->throttle_start_IO_period_timestamp[level];
+
+ msecs = info->throttle_io_periods[level];
+ period.tv_sec = msecs / 1000;
+ period.tv_usec = (msecs % 1000) * 1000;
+
+ timevaladd(&target, &period);
+
+ if (need_timer == FALSE || timevalcmp(&target, &min_target, <)) {
+ min_target = target;
+ need_timer = TRUE;
+ }
+ }
+ if (timevalcmp(&info->throttle_min_timer_deadline, &now, >)) {
+ if (timevalcmp(&info->throttle_min_timer_deadline, &min_target, >)) {
+ min_target = info->throttle_min_timer_deadline;
+ }
+ }
+
+ if (info->throttle_timer_active) {
+ if (thread_call_cancel(info->throttle_timer_call) == FALSE) {
+ /*
+ * couldn't kill the timer because it's already
+ * been dispatched, so don't try to start a new
+ * one... once we drop the lock, the timer will
+ * proceed and eventually re-run this function
+ */
+ need_timer = FALSE;
+ } else {
+ info->throttle_timer_active = 0;
+ }
+ }
+ if (need_timer == TRUE) {
+ /*
+ * This is defined as an int (32-bit) rather than a 64-bit
+ * value because it would need a really big period in the
+ * order of ~500 days to overflow this. So, we let this be
+ * 32-bit which allows us to use the clock_interval_to_deadline()
+ * routine.
+ */
+ int target_msecs;
+
+ if (info->throttle_timer_ref == 0) {
+ /*
+ * take a reference for the timer
+ */
+ throttle_info_ref(info);
+
+ info->throttle_timer_ref = 1;
+ }
+ elapsed = min_target;
+ timevalsub(&elapsed, &now);
+ target_msecs = elapsed.tv_sec * 1000 + elapsed.tv_usec / 1000;
+
+ if (target_msecs <= 0) {
+ /*
+ * we may have computed a deadline slightly in the past
+ * due to various factors... if so, just set the timer
+ * to go off in the near future (we don't need to be precise)
+ */
+ target_msecs = 1;
+ }
+ clock_interval_to_deadline(target_msecs, 1000000, &deadline);
+
+ thread_call_enter_delayed(info->throttle_timer_call, deadline);
+ info->throttle_timer_active = 1;
+ }
+ }
+ return throttle_level;
+}
+
+
+static void
+throttle_timer(struct _throttle_io_info_t *info)
+{
+ uthread_t ut, utlist;
+ struct timeval elapsed;
+ struct timeval now;
+ uint64_t elapsed_msecs;
+ int throttle_level;
+ int level;
+ int wake_level;
+ caddr_t wake_address = NULL;
+ boolean_t update_io_count = FALSE;
+ boolean_t need_wakeup = FALSE;
+ boolean_t need_release = FALSE;
+
+ ut = NULL;
+ lck_mtx_lock(&info->throttle_lock);
+
+ info->throttle_timer_active = 0;
+ microuptime(&now);
+
+ elapsed = now;
+ timevalsub(&elapsed, &info->throttle_start_IO_period_timestamp[THROTTLE_LEVEL_THROTTLED]);
+ elapsed_msecs = (uint64_t)elapsed.tv_sec * (uint64_t)1000 + (elapsed.tv_usec / 1000);
+
+ if (elapsed_msecs >= (uint64_t)info->throttle_io_periods[THROTTLE_LEVEL_THROTTLED]) {
+ wake_level = info->throttle_next_wake_level;
+
+ for (level = THROTTLE_LEVEL_START; level < THROTTLE_LEVEL_END; level++) {
+ elapsed = now;
+ timevalsub(&elapsed, &info->throttle_start_IO_period_timestamp[wake_level]);
+ elapsed_msecs = (uint64_t)elapsed.tv_sec * (uint64_t)1000 + (elapsed.tv_usec / 1000);
+
+ if (elapsed_msecs >= (uint64_t)info->throttle_io_periods[wake_level] && !TAILQ_EMPTY(&info->throttle_uthlist[wake_level])) {
+ /*
+ * we're closing out the current IO period...
+ * if we have a waiting thread, wake it up
+ * after we have reset the I/O window info
+ */
+ need_wakeup = TRUE;
+ update_io_count = TRUE;
+
+ info->throttle_next_wake_level = wake_level - 1;
+
+ if (info->throttle_next_wake_level == THROTTLE_LEVEL_START) {
+ info->throttle_next_wake_level = THROTTLE_LEVEL_END;
+ }
+
+ break;
+ }
+ wake_level--;
+
+ if (wake_level == THROTTLE_LEVEL_START) {
+ wake_level = THROTTLE_LEVEL_END;
+ }
+ }
+ }
+ if (need_wakeup == TRUE) {
+ if (!TAILQ_EMPTY(&info->throttle_uthlist[wake_level])) {
+ ut = (uthread_t)TAILQ_FIRST(&info->throttle_uthlist[wake_level]);
+ TAILQ_REMOVE(&info->throttle_uthlist[wake_level], ut, uu_throttlelist);
+ ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE;
+ ut->uu_is_throttled = false;
+
+ wake_address = (caddr_t)&ut->uu_on_throttlelist;
+ }
+ } else {
+ wake_level = THROTTLE_LEVEL_START;
+ }
+
+ throttle_level = throttle_timer_start(info, update_io_count, wake_level);
+
+ if (wake_address != NULL) {
+ wakeup(wake_address);
+ }
+
+ for (level = THROTTLE_LEVEL_THROTTLED; level <= throttle_level; level++) {
+ TAILQ_FOREACH_SAFE(ut, &info->throttle_uthlist[level], uu_throttlelist, utlist) {
+ TAILQ_REMOVE(&info->throttle_uthlist[level], ut, uu_throttlelist);
+ ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE;
+ ut->uu_is_throttled = false;
+
+ wakeup(&ut->uu_on_throttlelist);
+ }
+ }
+ if (info->throttle_timer_active == 0 && info->throttle_timer_ref) {
+ info->throttle_timer_ref = 0;
+ need_release = TRUE;
+ }
+ lck_mtx_unlock(&info->throttle_lock);
+
+ if (need_release == TRUE) {
+ throttle_info_rel(info);
+ }
+}
+
+
+static int
+throttle_add_to_list(struct _throttle_io_info_t *info, uthread_t ut, int mylevel, boolean_t insert_tail)
+{
+ boolean_t start_timer = FALSE;
+ int level = THROTTLE_LEVEL_START;
+
+ if (TAILQ_EMPTY(&info->throttle_uthlist[mylevel])) {
+ info->throttle_start_IO_period_timestamp[mylevel] = info->throttle_last_IO_timestamp[mylevel];
+ start_timer = TRUE;
+ }
+
+ if (insert_tail == TRUE) {
+ TAILQ_INSERT_TAIL(&info->throttle_uthlist[mylevel], ut, uu_throttlelist);
+ } else {
+ TAILQ_INSERT_HEAD(&info->throttle_uthlist[mylevel], ut, uu_throttlelist);
+ }
+
+ ut->uu_on_throttlelist = mylevel;
+
+ if (start_timer == TRUE) {
+ /* we may need to start or rearm the timer */
+ level = throttle_timer_start(info, FALSE, THROTTLE_LEVEL_START);
+
+ if (level == THROTTLE_LEVEL_END) {
+ if (ut->uu_on_throttlelist >= THROTTLE_LEVEL_THROTTLED) {
+ TAILQ_REMOVE(&info->throttle_uthlist[ut->uu_on_throttlelist], ut, uu_throttlelist);
+
+ ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE;
+ }
+ }
+ }
+ return level;
+}
+
+static void
+throttle_init_throttle_window(void)
+{
+ int throttle_window_size;
+
+ /*
+ * The hierarchy of throttle window values is as follows:
+ * - Global defaults
+ * - Device tree properties
+ * - Boot-args
+ * All values are specified in msecs.
+ */
+
+ /* Override global values with device-tree properties */
+ if (PE_get_default("kern.io_throttle_window_tier1", &throttle_window_size, sizeof(throttle_window_size))) {
+ throttle_windows_msecs[THROTTLE_LEVEL_TIER1] = throttle_window_size;
+ }
+
+ if (PE_get_default("kern.io_throttle_window_tier2", &throttle_window_size, sizeof(throttle_window_size))) {
+ throttle_windows_msecs[THROTTLE_LEVEL_TIER2] = throttle_window_size;
+ }
+
+ if (PE_get_default("kern.io_throttle_window_tier3", &throttle_window_size, sizeof(throttle_window_size))) {
+ throttle_windows_msecs[THROTTLE_LEVEL_TIER3] = throttle_window_size;
+ }
+
+ /* Override with boot-args */
+ if (PE_parse_boot_argn("io_throttle_window_tier1", &throttle_window_size, sizeof(throttle_window_size))) {
+ throttle_windows_msecs[THROTTLE_LEVEL_TIER1] = throttle_window_size;
+ }
+
+ if (PE_parse_boot_argn("io_throttle_window_tier2", &throttle_window_size, sizeof(throttle_window_size))) {
+ throttle_windows_msecs[THROTTLE_LEVEL_TIER2] = throttle_window_size;
+ }
+
+ if (PE_parse_boot_argn("io_throttle_window_tier3", &throttle_window_size, sizeof(throttle_window_size))) {
+ throttle_windows_msecs[THROTTLE_LEVEL_TIER3] = throttle_window_size;
+ }
+}
+
+static void
+throttle_init_throttle_period(struct _throttle_io_info_t *info, boolean_t isssd)
+{
+ int throttle_period_size;
+
+ /*
+ * The hierarchy of throttle period values is as follows:
+ * - Global defaults
+ * - Device tree properties
+ * - Boot-args
+ * All values are specified in msecs.
+ */
+
+ /* Assign global defaults */
+ if ((isssd == TRUE) && (info->throttle_is_fusion_with_priority == 0)) {
+ info->throttle_io_periods = &throttle_io_period_ssd_msecs[0];
+ } else {
+ info->throttle_io_periods = &throttle_io_period_msecs[0];
+ }
+
+ /* Override global values with device-tree properties */
+ if (PE_get_default("kern.io_throttle_period_tier1", &throttle_period_size, sizeof(throttle_period_size))) {
+ info->throttle_io_periods[THROTTLE_LEVEL_TIER1] = throttle_period_size;
+ }
+
+ if (PE_get_default("kern.io_throttle_period_tier2", &throttle_period_size, sizeof(throttle_period_size))) {
+ info->throttle_io_periods[THROTTLE_LEVEL_TIER2] = throttle_period_size;
+ }
+
+ if (PE_get_default("kern.io_throttle_period_tier3", &throttle_period_size, sizeof(throttle_period_size))) {
+ info->throttle_io_periods[THROTTLE_LEVEL_TIER3] = throttle_period_size;
+ }
+
+ /* Override with boot-args */
+ if (PE_parse_boot_argn("io_throttle_period_tier1", &throttle_period_size, sizeof(throttle_period_size))) {
+ info->throttle_io_periods[THROTTLE_LEVEL_TIER1] = throttle_period_size;
+ }
+
+ if (PE_parse_boot_argn("io_throttle_period_tier2", &throttle_period_size, sizeof(throttle_period_size))) {
+ info->throttle_io_periods[THROTTLE_LEVEL_TIER2] = throttle_period_size;
+ }
+
+ if (PE_parse_boot_argn("io_throttle_period_tier3", &throttle_period_size, sizeof(throttle_period_size))) {
+ info->throttle_io_periods[THROTTLE_LEVEL_TIER3] = throttle_period_size;
+ }
+}
+
+#if CONFIG_IOSCHED
+extern void vm_io_reprioritize_init(void);
+int iosched_enabled = 1;
+#endif
+
+void
+throttle_init(void)
+{
+ struct _throttle_io_info_t *info;
+ int i;
+ int level;
+#if CONFIG_IOSCHED
+ int iosched;
+#endif
+ /*
+ * allocate lock group attribute and group
+ */
+ throttle_lock_grp_attr = lck_grp_attr_alloc_init();
+ throttle_lock_grp = lck_grp_alloc_init("throttle I/O", throttle_lock_grp_attr);
+
+ /* Update throttle parameters based on device tree configuration */
+ throttle_init_throttle_window();
+
+ /*
+ * allocate the lock attribute
+ */
+ throttle_lock_attr = lck_attr_alloc_init();
+
+ for (i = 0; i < LOWPRI_MAX_NUM_DEV; i++) {
+ info = &_throttle_io_info[i];
+
+ lck_mtx_init(&info->throttle_lock, throttle_lock_grp, throttle_lock_attr);
+ info->throttle_timer_call = thread_call_allocate((thread_call_func_t)throttle_timer, (thread_call_param_t)info);
+
+ for (level = 0; level <= THROTTLE_LEVEL_END; level++) {
+ TAILQ_INIT(&info->throttle_uthlist[level]);
+ info->throttle_last_IO_pid[level] = 0;
+ info->throttle_inflight_count[level] = 0;
+ }
+ info->throttle_next_wake_level = THROTTLE_LEVEL_END;
+ info->throttle_disabled = 0;
+ info->throttle_is_fusion_with_priority = 0;
+ }
+#if CONFIG_IOSCHED
+ if (PE_parse_boot_argn("iosched", &iosched, sizeof(iosched))) {
+ iosched_enabled = iosched;
+ }
+ if (iosched_enabled) {
+ /* Initialize I/O Reprioritization mechanism */
+ vm_io_reprioritize_init();
+ }
+#endif
+}
+
+void
+sys_override_io_throttle(boolean_t enable_override)
+{
+ if (enable_override) {
+ lowpri_throttle_enabled = 0;
+ } else {
+ lowpri_throttle_enabled = 1;
+ }
+}
+
+int rethrottle_wakeups = 0;
+
+/*
+ * the uu_rethrottle_lock is used to synchronize this function
+ * with "throttle_lowpri_io" which is where a throttled thread
+ * will block... that function will grab this lock before beginning
+ * it's decision making process concerning the need to block, and
+ * hold it through the assert_wait. When that thread is awakened
+ * for any reason (timer or rethrottle), it will reacquire the
+ * uu_rethrottle_lock before determining if it really is ok for
+ * it to now run. This is the point at which the thread could
+ * enter a different throttling queue and reblock or return from
+ * the throttle w/o having waited out it's entire throttle if
+ * the rethrottle has now moved it out of any currently
+ * active throttle window.
+ *
+ *
+ * NOTES:
+ * 1 - This may be called with the task lock held.
+ * 2 - This may be called with preemption and interrupts disabled
+ * in the kqueue wakeup path so we can't take the throttle_lock which is a mutex
+ * 3 - This cannot safely dereference uu_throttle_info, as it may
+ * get deallocated out from under us
+ */
+
+void
+rethrottle_thread(uthread_t ut)
+{
+ /*
+ * If uthread doesn't have throttle state, then there's no chance
+ * of it needing a rethrottle.
+ */
+ if (ut->uu_throttle_info == NULL) {
+ return;
+ }
+
+ boolean_t s = ml_set_interrupts_enabled(FALSE);
+ lck_spin_lock(&ut->uu_rethrottle_lock);
+
+ if (!ut->uu_is_throttled) {
+ ut->uu_was_rethrottled = true;
+ } else {
+ int my_new_level = throttle_get_thread_throttle_level(ut);
+
+ if (my_new_level != ut->uu_on_throttlelist) {
+ /*
+ * ut is currently blocked (as indicated by
+ * ut->uu_is_throttled == true)
+ * and we're changing it's throttle level, so
+ * we need to wake it up.
+ */
+ ut->uu_is_throttled = false;
+ wakeup(&ut->uu_on_throttlelist);
+
+ rethrottle_wakeups++;
+ KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW, 102)), thread_tid(ut->uu_thread), ut->uu_on_throttlelist, my_new_level, 0, 0);
+ }
+ }
+ lck_spin_unlock(&ut->uu_rethrottle_lock);
+ ml_set_interrupts_enabled(s);
+}
+
+
+/*
+ * KPI routine
+ *
+ * Create and take a reference on a throttle info structure and return a
+ * pointer for the file system to use when calling throttle_info_update.
+ * Calling file system must have a matching release for every create.
+ */
+void *
+throttle_info_create(void)
+{
+ struct _throttle_io_info_t *info;
+ int level;
+
+ MALLOC(info, struct _throttle_io_info_t *, sizeof(*info), M_TEMP, M_ZERO | M_WAITOK);
+ /* Should never happen but just in case */
+ if (info == NULL) {
+ return NULL;
+ }
+ /* Mark that this one was allocated and needs to be freed */
+ DEBUG_ALLOC_THROTTLE_INFO("Creating info = %p\n", info, info );
+ info->throttle_alloc = TRUE;
+
+ lck_mtx_init(&info->throttle_lock, throttle_lock_grp, throttle_lock_attr);
+ info->throttle_timer_call = thread_call_allocate((thread_call_func_t)throttle_timer, (thread_call_param_t)info);
+
+ for (level = 0; level <= THROTTLE_LEVEL_END; level++) {
+ TAILQ_INIT(&info->throttle_uthlist[level]);
+ }
+ info->throttle_next_wake_level = THROTTLE_LEVEL_END;
+
+ /* Take a reference */
+ OSIncrementAtomic(&info->throttle_refcnt);
+ return info;
+}
+
+/*
+ * KPI routine
+ *
+ * Release the throttle info pointer if all the reference are gone. Should be
+ * called to release reference taken by throttle_info_create
+ */
+void
+throttle_info_release(void *throttle_info)
+{
+ DEBUG_ALLOC_THROTTLE_INFO("Releaseing info = %p\n",
+ (struct _throttle_io_info_t *)throttle_info,
+ (struct _throttle_io_info_t *)throttle_info);
+ if (throttle_info) { /* Just to be careful */
+ throttle_info_rel(throttle_info);
+ }
+}
+
+/*
+ * KPI routine
+ *
+ * File Systems that create an info structure, need to call this routine in
+ * their mount routine (used by cluster code). File Systems that call this in
+ * their mount routines must call throttle_info_mount_rel in their unmount
+ * routines.
+ */
+void
+throttle_info_mount_ref(mount_t mp, void *throttle_info)
+{
+ if ((throttle_info == NULL) || (mp == NULL)) {
+ return;
+ }
+ throttle_info_ref(throttle_info);
+
+ /*
+ * We already have a reference release it before adding the new one
+ */
+ if (mp->mnt_throttle_info) {
+ throttle_info_rel(mp->mnt_throttle_info);
+ }
+ mp->mnt_throttle_info = throttle_info;
+}
+
+/*
+ * Private KPI routine
+ *
+ * return a handle for accessing throttle_info given a throttle_mask. The
+ * handle must be released by throttle_info_rel_by_mask
+ */
+int
+throttle_info_ref_by_mask(uint64_t throttle_mask, throttle_info_handle_t *throttle_info_handle)
+{
+ int dev_index;
+ struct _throttle_io_info_t *info;
+
+ if (throttle_info_handle == NULL) {
+ return EINVAL;
+ }
+
+ dev_index = num_trailing_0(throttle_mask);
+ info = &_throttle_io_info[dev_index];
+ throttle_info_ref(info);
+ *(struct _throttle_io_info_t**)throttle_info_handle = info;
+
+ return 0;
+}
+
+/*
+ * Private KPI routine
+ *
+ * release the handle obtained by throttle_info_ref_by_mask
+ */
+void
+throttle_info_rel_by_mask(throttle_info_handle_t throttle_info_handle)
+{
+ /*
+ * for now the handle is just a pointer to _throttle_io_info_t
+ */
+ throttle_info_rel((struct _throttle_io_info_t*)throttle_info_handle);
+}
+
+/*
+ * KPI routine
+ *
+ * File Systems that throttle_info_mount_ref, must call this routine in their
+ * umount routine.
+ */
+void
+throttle_info_mount_rel(mount_t mp)
+{
+ if (mp->mnt_throttle_info) {
+ throttle_info_rel(mp->mnt_throttle_info);
+ }
+ mp->mnt_throttle_info = NULL;
+}
+
+/*
+ * Reset throttling periods for the given mount point
+ *
+ * private interface used by disk conditioner to reset
+ * throttling periods when 'is_ssd' status changes
+ */
+void
+throttle_info_mount_reset_period(mount_t mp, int isssd)
+{
+ struct _throttle_io_info_t *info;
+
+ if (mp == NULL) {
+ info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1];
+ } else if (mp->mnt_throttle_info == NULL) {
+ info = &_throttle_io_info[mp->mnt_devbsdunit];
+ } else {
+ info = mp->mnt_throttle_info;
+ }
+
+ throttle_init_throttle_period(info, isssd);
+}
+
+void
+throttle_info_get_last_io_time(mount_t mp, struct timeval *tv)
+{
+ struct _throttle_io_info_t *info;
+
+ if (mp == NULL) {
+ info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1];
+ } else if (mp->mnt_throttle_info == NULL) {
+ info = &_throttle_io_info[mp->mnt_devbsdunit];
+ } else {
+ info = mp->mnt_throttle_info;
+ }
+
+ *tv = info->throttle_last_write_timestamp;
+}
+
+void
+update_last_io_time(mount_t mp)
+{
+ struct _throttle_io_info_t *info;
+
+ if (mp == NULL) {
+ info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1];
+ } else if (mp->mnt_throttle_info == NULL) {
+ info = &_throttle_io_info[mp->mnt_devbsdunit];
+ } else {
+ info = mp->mnt_throttle_info;
+ }
+
+ microuptime(&info->throttle_last_write_timestamp);
+ if (mp != NULL) {
+ mp->mnt_last_write_completed_timestamp = info->throttle_last_write_timestamp;
+ }
+}
+
+int
+throttle_get_io_policy(uthread_t *ut)
+{
+ if (ut != NULL) {
+ *ut = get_bsdthread_info(current_thread());
+ }
+
+ return proc_get_effective_thread_policy(current_thread(), TASK_POLICY_IO);
+}
+
+int
+throttle_get_passive_io_policy(uthread_t *ut)
+{
+ if (ut != NULL) {
+ *ut = get_bsdthread_info(current_thread());
+ }
+
+ return proc_get_effective_thread_policy(current_thread(), TASK_POLICY_PASSIVE_IO);
+}
+
+
+static int
+throttle_get_thread_throttle_level(uthread_t ut)
+{
+ uthread_t *ut_p = (ut == NULL) ? &ut : NULL;
+ int io_tier = throttle_get_io_policy(ut_p);
+
+ return throttle_get_thread_throttle_level_internal(ut, io_tier);
+}
+
+/*
+ * Return a throttle level given an existing I/O tier (such as returned by throttle_get_io_policy)
+ */
+static int
+throttle_get_thread_throttle_level_internal(uthread_t ut, int io_tier)
+{
+ int thread_throttle_level = io_tier;
+ int user_idle_level;
+
+ assert(ut != NULL);
+
+ /* Bootcache misses should always be throttled */
+ if (ut->uu_throttle_bc) {
+ thread_throttle_level = THROTTLE_LEVEL_TIER3;
+ }
+
+ /*
+ * Issue tier3 I/O as tier2 when the user is idle
+ * to allow maintenance tasks to make more progress.
+ *
+ * Assume any positive idle level is enough... for now it's
+ * only ever 0 or 128 but this is not defined anywhere.
+ */
+ if (thread_throttle_level >= THROTTLE_LEVEL_TIER3) {
+ user_idle_level = timer_get_user_idle_level();
+ if (user_idle_level > 0) {
+ thread_throttle_level--;
+ }
+ }
+
+ return thread_throttle_level;
+}
+
+/*
+ * I/O will be throttled if either of the following are true:
+ * - Higher tiers have in-flight I/O
+ * - The time delta since the last start/completion of a higher tier is within the throttle window interval
+ *
+ * In-flight I/O is bookended by throttle_info_update_internal/throttle_info_end_io_internal
+ */
+static int
+throttle_io_will_be_throttled_internal(void * throttle_info, int * mylevel, int * throttling_level)
+{
+ struct _throttle_io_info_t *info = throttle_info;
+ struct timeval elapsed;
+ struct timeval now;
+ uint64_t elapsed_msecs;
+ int thread_throttle_level;
+ int throttle_level;
+
+ if ((thread_throttle_level = throttle_get_thread_throttle_level(NULL)) < THROTTLE_LEVEL_THROTTLED) {
+ return THROTTLE_DISENGAGED;
+ }
+
+ microuptime(&now);
+
+ for (throttle_level = THROTTLE_LEVEL_START; throttle_level < thread_throttle_level; throttle_level++) {
+ if (info->throttle_inflight_count[throttle_level]) {
+ break;
+ }
+ elapsed = now;
+ timevalsub(&elapsed, &info->throttle_window_start_timestamp[throttle_level]);
+ elapsed_msecs = (uint64_t)elapsed.tv_sec * (uint64_t)1000 + (elapsed.tv_usec / 1000);
+
+ if (elapsed_msecs < (uint64_t)throttle_windows_msecs[thread_throttle_level]) {
+ break;
+ }
+ }
+ if (throttle_level >= thread_throttle_level) {
+ /*
+ * we're beyond all of the throttle windows
+ * that affect the throttle level of this thread,
+ * so go ahead and treat as normal I/O
+ */
+ return THROTTLE_DISENGAGED;
+ }
+ if (mylevel) {
+ *mylevel = thread_throttle_level;
+ }
+ if (throttling_level) {
+ *throttling_level = throttle_level;
+ }
+
+ if (info->throttle_io_count != info->throttle_io_count_begin) {
+ /*
+ * we've already issued at least one throttleable I/O
+ * in the current I/O window, so avoid issuing another one
+ */
+ return THROTTLE_NOW;
+ }
+ /*
+ * we're in the throttle window, so
+ * cut the I/O size back
+ */
+ return THROTTLE_ENGAGED;
+}
+
+/*
+ * If we have a mount point and it has a throttle info pointer then
+ * use it to do the check, otherwise use the device unit number to find
+ * the correct throttle info array element.
+ */
+int
+throttle_io_will_be_throttled(__unused int lowpri_window_msecs, mount_t mp)
+{
+ struct _throttle_io_info_t *info;
+
+ /*
+ * Should we just return zero if no mount point
+ */
+ if (mp == NULL) {
+ info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1];
+ } else if (mp->mnt_throttle_info == NULL) {
+ info = &_throttle_io_info[mp->mnt_devbsdunit];
+ } else {
+ info = mp->mnt_throttle_info;
+ }
+
+ if (info->throttle_is_fusion_with_priority) {
+ uthread_t ut = get_bsdthread_info(current_thread());
+ if (ut->uu_lowpri_window == 0) {
+ return THROTTLE_DISENGAGED;
+ }
+ }
+
+ if (info->throttle_disabled) {
+ return THROTTLE_DISENGAGED;
+ } else {
+ return throttle_io_will_be_throttled_internal(info, NULL, NULL);
+ }
+}
+
+/*
+ * Routine to increment I/O throttling counters maintained in the proc
+ */
+
+static void
+throttle_update_proc_stats(pid_t throttling_pid, int count)
+{
+ proc_t throttling_proc;
+ proc_t throttled_proc = current_proc();
+
+ /* The throttled_proc is always the current proc; so we are not concerned with refs */
+ OSAddAtomic64(count, &(throttled_proc->was_throttled));
+
+ /* The throttling pid might have exited by now */
+ throttling_proc = proc_find(throttling_pid);
+ if (throttling_proc != PROC_NULL) {
+ OSAddAtomic64(count, &(throttling_proc->did_throttle));
+ proc_rele(throttling_proc);
+ }
+}
+
+/*
+ * Block until woken up by the throttle timer or by a rethrottle call.
+ * As long as we hold the throttle_lock while querying the throttle tier, we're
+ * safe against seeing an old throttle tier after a rethrottle.
+ */
+uint32_t
+throttle_lowpri_io(int sleep_amount)
+{
+ uthread_t ut;
+ struct _throttle_io_info_t *info;
+ int throttle_type = 0;
+ int mylevel = 0;
+ int throttling_level = THROTTLE_LEVEL_NONE;
+ int sleep_cnt = 0;
+ uint32_t throttle_io_period_num = 0;
+ boolean_t insert_tail = TRUE;
+ boolean_t s;
+
+ ut = get_bsdthread_info(current_thread());
+
+ if (ut->uu_lowpri_window == 0) {
+ return 0;
+ }
+
+ info = ut->uu_throttle_info;
+
+ if (info == NULL) {
+ ut->uu_throttle_bc = false;
+ ut->uu_lowpri_window = 0;
+ return 0;
+ }
+ lck_mtx_lock(&info->throttle_lock);
+ assert(ut->uu_on_throttlelist < THROTTLE_LEVEL_THROTTLED);
+
+ if (sleep_amount == 0) {
+ goto done;
+ }
+
+ if (sleep_amount == 1 && !ut->uu_throttle_bc) {
+ sleep_amount = 0;
+ }
+
+ throttle_io_period_num = info->throttle_io_period_num;
+
+ ut->uu_was_rethrottled = false;
+
+ while ((throttle_type = throttle_io_will_be_throttled_internal(info, &mylevel, &throttling_level))) {
+ if (throttle_type == THROTTLE_ENGAGED) {
+ if (sleep_amount == 0) {
+ break;
+ }
+ if (info->throttle_io_period_num < throttle_io_period_num) {
+ break;
+ }
+ if ((info->throttle_io_period_num - throttle_io_period_num) >= (uint32_t)sleep_amount) {
+ break;
+ }
+ }
+ /*
+ * keep the same position in the list if "rethrottle_thread" changes our throttle level and
+ * then puts us back to the original level before we get a chance to run
+ */
+ if (ut->uu_on_throttlelist >= THROTTLE_LEVEL_THROTTLED && ut->uu_on_throttlelist != mylevel) {
+ /*
+ * must have been awakened via "rethrottle_thread" (the timer pulls us off the list)
+ * and we've changed our throttling level, so pull ourselves off of the appropriate list
+ * and make sure we get put on the tail of the new list since we're starting anew w/r to
+ * the throttling engine
+ */
+ TAILQ_REMOVE(&info->throttle_uthlist[ut->uu_on_throttlelist], ut, uu_throttlelist);
+ ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE;
+ insert_tail = TRUE;
+ }
+ if (ut->uu_on_throttlelist < THROTTLE_LEVEL_THROTTLED) {
+ if (throttle_add_to_list(info, ut, mylevel, insert_tail) == THROTTLE_LEVEL_END) {
+ goto done;
+ }
+ }
+ assert(throttling_level >= THROTTLE_LEVEL_START && throttling_level <= THROTTLE_LEVEL_END);
+
+ s = ml_set_interrupts_enabled(FALSE);
+ lck_spin_lock(&ut->uu_rethrottle_lock);
+
+ /*
+ * this is the critical section w/r to our interaction
+ * with "rethrottle_thread"
+ */
+ if (ut->uu_was_rethrottled) {
+ lck_spin_unlock(&ut->uu_rethrottle_lock);
+ ml_set_interrupts_enabled(s);
+ lck_mtx_yield(&info->throttle_lock);
+
+ KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW, 103)), thread_tid(ut->uu_thread), ut->uu_on_throttlelist, 0, 0, 0);
+
+ ut->uu_was_rethrottled = false;
+ continue;
+ }
+ KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_THROTTLE, PROCESS_THROTTLED)) | DBG_FUNC_NONE,
+ info->throttle_last_IO_pid[throttling_level], throttling_level, proc_selfpid(), mylevel, 0);
+
+ if (sleep_cnt == 0) {
+ KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW, 97)) | DBG_FUNC_START,
+ throttle_windows_msecs[mylevel], info->throttle_io_periods[mylevel], info->throttle_io_count, 0, 0);
+ throttled_count[mylevel]++;
+ }
+ ut->uu_wmesg = "throttle_lowpri_io";
+
+ assert_wait((caddr_t)&ut->uu_on_throttlelist, THREAD_UNINT);
+
+ ut->uu_is_throttled = true;
+ lck_spin_unlock(&ut->uu_rethrottle_lock);
+ ml_set_interrupts_enabled(s);
+
+ lck_mtx_unlock(&info->throttle_lock);
+
+ thread_block(THREAD_CONTINUE_NULL);
+
+ ut->uu_wmesg = NULL;
+
+ ut->uu_is_throttled = false;
+ ut->uu_was_rethrottled = false;
+
+ lck_mtx_lock(&info->throttle_lock);
+
+ sleep_cnt++;
+
+ if (sleep_amount == 0) {
+ insert_tail = FALSE;
+ } else if (info->throttle_io_period_num < throttle_io_period_num ||
+ (info->throttle_io_period_num - throttle_io_period_num) >= (uint32_t)sleep_amount) {
+ insert_tail = FALSE;
+ sleep_amount = 0;
+ }
+ }
+done:
+ if (ut->uu_on_throttlelist >= THROTTLE_LEVEL_THROTTLED) {
+ TAILQ_REMOVE(&info->throttle_uthlist[ut->uu_on_throttlelist], ut, uu_throttlelist);
+ ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE;
+ }
+ lck_mtx_unlock(&info->throttle_lock);
+
+ if (sleep_cnt) {
+ KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_FSRW, 97)) | DBG_FUNC_END,
+ throttle_windows_msecs[mylevel], info->throttle_io_periods[mylevel], info->throttle_io_count, 0, 0);
+ /*
+ * We update the stats for the last pid which opened a throttle window for the throttled thread.
+ * This might not be completely accurate since the multiple throttles seen by the lower tier pid
+ * might have been caused by various higher prio pids. However, updating these stats accurately
+ * means doing a proc_find while holding the throttle lock which leads to deadlock.
+ */
+ throttle_update_proc_stats(info->throttle_last_IO_pid[throttling_level], sleep_cnt);
+ }
+
+ ut->uu_throttle_info = NULL;
+ ut->uu_throttle_bc = false;
+ ut->uu_lowpri_window = 0;
+
+ throttle_info_rel(info);
+
+ return sleep_cnt;
+}
+
+/*
+ * returns TRUE if the throttle_lowpri_io called with the same sleep_amount would've slept
+ * This function mimics the most of the throttle_lowpri_io checks but without actual sleeping
+ */
+int
+throttle_lowpri_io_will_be_throttled(int sleep_amount)
+{
+ if (sleep_amount == 0) {
+ return FALSE;
+ }
+
+ uthread_t ut = get_bsdthread_info(current_thread());
+ if (ut->uu_lowpri_window == 0) {
+ return FALSE;
+ }
+
+ struct _throttle_io_info_t *info = ut->uu_throttle_info;
+ if (info == NULL) {
+ return FALSE;
+ }
+
+ lck_mtx_lock(&info->throttle_lock);
+ assert(ut->uu_on_throttlelist < THROTTLE_LEVEL_THROTTLED);
+
+ if (sleep_amount == 1 && !ut->uu_throttle_bc) {
+ sleep_amount = 0;
+ }
+
+ int result = FALSE;
+
+ int throttle_type = throttle_io_will_be_throttled_internal(info, NULL, NULL);
+ if (throttle_type > THROTTLE_DISENGAGED) {
+ result = TRUE;
+ if ((throttle_type == THROTTLE_ENGAGED) && (sleep_amount == 0)) {
+ result = FALSE;
+ }
+ }
+
+ lck_mtx_unlock(&info->throttle_lock);
+
+ return result;
+}
+
+
+/*
+ * KPI routine
+ *
+ * set a kernel thread's IO policy. policy can be:
+ * IOPOL_NORMAL, IOPOL_THROTTLE, IOPOL_PASSIVE, IOPOL_UTILITY, IOPOL_STANDARD
+ *
+ * explanations about these policies are in the man page of setiopolicy_np
+ */
+void
+throttle_set_thread_io_policy(int policy)
+{
+ proc_set_thread_policy(current_thread(), TASK_POLICY_INTERNAL, TASK_POLICY_IOPOL, policy);
+}
+
+int
+throttle_get_thread_effective_io_policy()
+{
+ return proc_get_effective_thread_policy(current_thread(), TASK_POLICY_IO);
+}
+
+void
+throttle_info_reset_window(uthread_t ut)
+{
+ struct _throttle_io_info_t *info;
+
+ if (ut == NULL) {
+ ut = get_bsdthread_info(current_thread());
+ }
+
+ if ((info = ut->uu_throttle_info)) {
+ throttle_info_rel(info);
+
+ ut->uu_throttle_info = NULL;
+ ut->uu_lowpri_window = 0;
+ ut->uu_throttle_bc = false;
+ }
+}
+
+static
+void
+throttle_info_set_initial_window(uthread_t ut, struct _throttle_io_info_t *info, boolean_t BC_throttle, boolean_t isssd)
+{
+ if (lowpri_throttle_enabled == 0 || info->throttle_disabled) {
+ return;
+ }
+
+ if (info->throttle_io_periods == 0) {
+ throttle_init_throttle_period(info, isssd);
+ }
+ if (ut->uu_throttle_info == NULL) {
+ ut->uu_throttle_info = info;
+ throttle_info_ref(info);
+ DEBUG_ALLOC_THROTTLE_INFO("updating info = %p\n", info, info );
+
+ ut->uu_lowpri_window = 1;
+ ut->uu_throttle_bc = BC_throttle;
+ }
+}
+
+/*
+ * Update inflight IO count and throttling window
+ * Should be called when an IO is done
+ *
+ * Only affects IO that was sent through spec_strategy
+ */
+void
+throttle_info_end_io(buf_t bp)
+{
+ mount_t mp;
+ struct bufattr *bap;
+ struct _throttle_io_info_t *info;
+ int io_tier;
+
+ bap = &bp->b_attr;
+ if (!ISSET(bap->ba_flags, BA_STRATEGY_TRACKED_IO)) {
+ return;
+ }
+ CLR(bap->ba_flags, BA_STRATEGY_TRACKED_IO);
+
+ mp = buf_vnode(bp)->v_mount;
+ if (mp != NULL) {
+ info = &_throttle_io_info[mp->mnt_devbsdunit];
+ } else {
+ info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1];
+ }
+
+ io_tier = GET_BUFATTR_IO_TIER(bap);
+ if (ISSET(bap->ba_flags, BA_IO_TIER_UPGRADE)) {
+ io_tier--;
+ }
+
+ throttle_info_end_io_internal(info, io_tier);
+}
+
+/*
+ * Decrement inflight count initially incremented by throttle_info_update_internal
+ */
+static
+void
+throttle_info_end_io_internal(struct _throttle_io_info_t *info, int throttle_level)
+{
+ if (throttle_level == THROTTLE_LEVEL_NONE) {
+ return;
+ }
+
+ microuptime(&info->throttle_window_start_timestamp[throttle_level]);
+ OSDecrementAtomic(&info->throttle_inflight_count[throttle_level]);
+ assert(info->throttle_inflight_count[throttle_level] >= 0);
+}
+
+/*
+ * If inflight is TRUE and bap is NULL then the caller is responsible for calling
+ * throttle_info_end_io_internal to avoid leaking in-flight I/O.
+ */
+static
+int
+throttle_info_update_internal(struct _throttle_io_info_t *info, uthread_t ut, int flags, boolean_t isssd, boolean_t inflight, struct bufattr *bap)
+{
+ int thread_throttle_level;
+
+ if (lowpri_throttle_enabled == 0 || info->throttle_disabled) {
+ return THROTTLE_LEVEL_NONE;
+ }
+
+ if (ut == NULL) {
+ ut = get_bsdthread_info(current_thread());
+ }
+
+ if (bap && inflight && !ut->uu_throttle_bc) {
+ thread_throttle_level = GET_BUFATTR_IO_TIER(bap);
+ if (ISSET(bap->ba_flags, BA_IO_TIER_UPGRADE)) {
+ thread_throttle_level--;
+ }
+ } else {
+ thread_throttle_level = throttle_get_thread_throttle_level(ut);
+ }
+
+ if (thread_throttle_level != THROTTLE_LEVEL_NONE) {
+ if (!ISSET(flags, B_PASSIVE)) {
+ info->throttle_last_IO_pid[thread_throttle_level] = proc_selfpid();
+ if (inflight && !ut->uu_throttle_bc) {
+ if (NULL != bap) {
+ SET(bap->ba_flags, BA_STRATEGY_TRACKED_IO);
+ }
+ OSIncrementAtomic(&info->throttle_inflight_count[thread_throttle_level]);
+ } else {
+ microuptime(&info->throttle_window_start_timestamp[thread_throttle_level]);
+ }
+ KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_THROTTLE, OPEN_THROTTLE_WINDOW)) | DBG_FUNC_NONE,
+ current_proc()->p_pid, thread_throttle_level, 0, 0, 0);
+ }
+ microuptime(&info->throttle_last_IO_timestamp[thread_throttle_level]);
+ }
+
+
+ if (thread_throttle_level >= THROTTLE_LEVEL_THROTTLED) {
+ /*
+ * I'd really like to do the IOSleep here, but
+ * we may be holding all kinds of filesystem related locks
+ * and the pages for this I/O marked 'busy'...
+ * we don't want to cause a normal task to block on
+ * one of these locks while we're throttling a task marked
+ * for low priority I/O... we'll mark the uthread and
+ * do the delay just before we return from the system
+ * call that triggered this I/O or from vnode_pagein
+ */
+ OSAddAtomic(1, &info->throttle_io_count);
+
+ throttle_info_set_initial_window(ut, info, FALSE, isssd);
+ }
+
+ return thread_throttle_level;
+}
+
+void *
+throttle_info_update_by_mount(mount_t mp)
+{
+ struct _throttle_io_info_t *info;
+ uthread_t ut;
+ boolean_t isssd = FALSE;
+
+ ut = get_bsdthread_info(current_thread());
+
+ if (mp != NULL) {
+ if (disk_conditioner_mount_is_ssd(mp)) {
+ isssd = TRUE;
+ }
+ info = &_throttle_io_info[mp->mnt_devbsdunit];
+ } else {
+ info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1];
+ }
+
+ if (!ut->uu_lowpri_window) {
+ throttle_info_set_initial_window(ut, info, FALSE, isssd);
+ }
+
+ return info;
+}
+
+
+/*
+ * KPI routine
+ *
+ * this is usually called before every I/O, used for throttled I/O
+ * book keeping. This routine has low overhead and does not sleep
+ */
+void
+throttle_info_update(void *throttle_info, int flags)
+{
+ if (throttle_info) {
+ throttle_info_update_internal(throttle_info, NULL, flags, FALSE, FALSE, NULL);
+ }
+}
+
+/*
+ * KPI routine
+ *
+ * this is usually called before every I/O, used for throttled I/O
+ * book keeping. This routine has low overhead and does not sleep
+ */
+void
+throttle_info_update_by_mask(void *throttle_info_handle, int flags)
+{
+ void *throttle_info = throttle_info_handle;
+
+ /*
+ * for now we only use the lowest bit of the throttle mask, so the
+ * handle is the same as the throttle_info. Later if we store a
+ * set of throttle infos in the handle, we will want to loop through
+ * them and call throttle_info_update in a loop
+ */
+ throttle_info_update(throttle_info, flags);
+}
+/*
+ * KPI routine
+ *
+ * This routine marks the throttle info as disabled. Used for mount points which
+ * support I/O scheduling.
+ */
+
+void
+throttle_info_disable_throttle(int devno, boolean_t isfusion)
+{
+ struct _throttle_io_info_t *info;
+
+ if (devno < 0 || devno >= LOWPRI_MAX_NUM_DEV) {
+ panic("Illegal devno (%d) passed into throttle_info_disable_throttle()", devno);
+ }
+
+ info = &_throttle_io_info[devno];
+ // don't disable software throttling on devices that are part of a fusion device
+ // and override the software throttle periods to use HDD periods
+ if (isfusion) {
+ info->throttle_is_fusion_with_priority = isfusion;
+ throttle_init_throttle_period(info, FALSE);
+ }
+ info->throttle_disabled = !info->throttle_is_fusion_with_priority;
+ return;
+}
+
+
+/*
+ * KPI routine (private)
+ * Called to determine if this IO is being throttled to this level so that it can be treated specially
+ */
+int
+throttle_info_io_will_be_throttled(void * throttle_info, int policy)
+{
+ struct _throttle_io_info_t *info = throttle_info;
+ struct timeval elapsed;
+ uint64_t elapsed_msecs;
+ int throttle_level;
+ int thread_throttle_level;
+
+ switch (policy) {
+ case IOPOL_THROTTLE:
+ thread_throttle_level = THROTTLE_LEVEL_TIER3;
+ break;
+ case IOPOL_UTILITY:
+ thread_throttle_level = THROTTLE_LEVEL_TIER2;
+ break;
+ case IOPOL_STANDARD:
+ thread_throttle_level = THROTTLE_LEVEL_TIER1;
+ break;
+ default:
+ thread_throttle_level = THROTTLE_LEVEL_TIER0;
+ break;
+ }
+ for (throttle_level = THROTTLE_LEVEL_START; throttle_level < thread_throttle_level; throttle_level++) {
+ if (info->throttle_inflight_count[throttle_level]) {
+ break;
+ }
+
+ microuptime(&elapsed);
+ timevalsub(&elapsed, &info->throttle_window_start_timestamp[throttle_level]);
+ elapsed_msecs = (uint64_t)elapsed.tv_sec * (uint64_t)1000 + (elapsed.tv_usec / 1000);
+
+ if (elapsed_msecs < (uint64_t)throttle_windows_msecs[thread_throttle_level]) {
+ break;
+ }
+ }
+ if (throttle_level >= thread_throttle_level) {
+ /*
+ * we're beyond all of the throttle windows
+ * so go ahead and treat as normal I/O
+ */
+ return THROTTLE_DISENGAGED;
+ }
+ /*
+ * we're in the throttle window
+ */
+ return THROTTLE_ENGAGED;
+}
+
+int
+throttle_lowpri_window(void)
+{
+ struct uthread *ut = get_bsdthread_info(current_thread());
+ return ut->uu_lowpri_window;
+}
+
+
+#if CONFIG_IOSCHED
+int upl_get_cached_tier(void *);
+#endif
+
+int
+spec_strategy(struct vnop_strategy_args *ap)
+{
+ buf_t bp;
+ int bflags;
+ int io_tier;
+ int passive;
+ dev_t bdev;
+ uthread_t ut;
+ mount_t mp;
+ struct bufattr *bap;
+ int strategy_ret;
+ struct _throttle_io_info_t *throttle_info;
+ boolean_t isssd = FALSE;
+ boolean_t inflight = FALSE;
+ boolean_t upgrade = FALSE;
+ int code = 0;
+
+#if !CONFIG_EMBEDDED
+ proc_t curproc = current_proc();
+#endif /* !CONFIG_EMBEDDED */
+
+ bp = ap->a_bp;
+ bdev = buf_device(bp);
+ mp = buf_vnode(bp)->v_mount;
+ bap = &bp->b_attr;
+
+#if CONFIG_IOSCHED
+ if (bp->b_flags & B_CLUSTER) {
+ io_tier = upl_get_cached_tier(bp->b_upl);
+
+ if (io_tier == -1) {
+ io_tier = throttle_get_io_policy(&ut);
+ }
+#if DEVELOPMENT || DEBUG
+ else {
+ int my_io_tier = throttle_get_io_policy(&ut);
+
+ if (io_tier != my_io_tier) {
+ KERNEL_DEBUG_CONSTANT((FSDBG_CODE(DBG_THROTTLE, IO_TIER_UPL_MISMATCH)) | DBG_FUNC_NONE, buf_kernel_addrperm_addr(bp), my_io_tier, io_tier, 0, 0);
+ }
+ }
+#endif
+ } else {
+ io_tier = throttle_get_io_policy(&ut);
+ }
+#else
+ io_tier = throttle_get_io_policy(&ut);
+#endif
+ passive = throttle_get_passive_io_policy(&ut);
+
+ /*
+ * Mark if the I/O was upgraded by throttle_get_thread_throttle_level
+ * while preserving the original issued tier (throttle_get_io_policy
+ * does not return upgraded tiers)
+ */
+ if (mp && io_tier > throttle_get_thread_throttle_level_internal(ut, io_tier)) {
+#if CONFIG_IOSCHED
+ if (!(mp->mnt_ioflags & MNT_IOFLAGS_IOSCHED_SUPPORTED)) {
+ upgrade = TRUE;
+ }
+#else /* CONFIG_IOSCHED */
+ upgrade = TRUE;
+#endif /* CONFIG_IOSCHED */
+ }
+
+ if (bp->b_flags & B_META) {
+ bap->ba_flags |= BA_META;
+ }
+
+#if CONFIG_IOSCHED
+ /*
+ * For I/O Scheduling, we currently do not have a way to track and expedite metadata I/Os.
+ * To ensure we dont get into priority inversions due to metadata I/Os, we use the following rules:
+ * For metadata reads, ceil all I/Os to IOSCHED_METADATA_TIER & mark them passive if the I/O tier was upgraded
+ * For metadata writes, unconditionally mark them as IOSCHED_METADATA_TIER and passive
+ */
+ if (bap->ba_flags & BA_META) {
+ if ((mp && (mp->mnt_ioflags & MNT_IOFLAGS_IOSCHED_SUPPORTED)) || (bap->ba_flags & BA_IO_SCHEDULED)) {
+ if (bp->b_flags & B_READ) {
+ if (io_tier > IOSCHED_METADATA_TIER) {
+ io_tier = IOSCHED_METADATA_TIER;
+ passive = 1;
+ }
+ } else {
+ io_tier = IOSCHED_METADATA_TIER;
+ passive = 1;
+ }
+ }
+ }
+#endif /* CONFIG_IOSCHED */
+
+ SET_BUFATTR_IO_TIER(bap, io_tier);
+
+ if (passive) {
+ bp->b_flags |= B_PASSIVE;
+ bap->ba_flags |= BA_PASSIVE;
+ }
+
+#if !CONFIG_EMBEDDED
+ if ((curproc != NULL) && ((curproc->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP)) {
+ bap->ba_flags |= BA_DELAYIDLESLEEP;
+ }
+#endif /* !CONFIG_EMBEDDED */
+
+ bflags = bp->b_flags;
+
+ if (((bflags & B_READ) == 0) && ((bflags & B_ASYNC) == 0)) {
+ bufattr_markquickcomplete(bap);
+ }
+
+ if (bflags & B_READ) {
+ code |= DKIO_READ;
+ }
+ if (bflags & B_ASYNC) {
+ code |= DKIO_ASYNC;
+ }
+
+ if (bap->ba_flags & BA_META) {
+ code |= DKIO_META;
+ } else if (bflags & B_PAGEIO) {
+ code |= DKIO_PAGING;
+ }
+
+ if (io_tier != 0) {
+ code |= DKIO_THROTTLE;
+ }
+
+ code |= ((io_tier << DKIO_TIER_SHIFT) & DKIO_TIER_MASK);
+
+ if (bflags & B_PASSIVE) {
+ code |= DKIO_PASSIVE;
+ }
+
+ if (bap->ba_flags & BA_NOCACHE) {
+ code |= DKIO_NOCACHE;
+ }
+
+ if (upgrade) {
+ code |= DKIO_TIER_UPGRADE;
+ SET(bap->ba_flags, BA_IO_TIER_UPGRADE);
+ }
+
+ if (kdebug_enable) {
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON, FSDBG_CODE(DBG_DKRW, code) | DBG_FUNC_NONE,
+ buf_kernel_addrperm_addr(bp), bdev, buf_blkno(bp), buf_count(bp), 0);
+ }
+
+ thread_update_io_stats(current_thread(), buf_count(bp), code);
+
+ if (mp != NULL) {
+ if (disk_conditioner_mount_is_ssd(mp)) {
+ isssd = TRUE;
+ }
+ /*
+ * Partially initialized mounts don't have a final devbsdunit and should not be tracked.
+ * Verify that devbsdunit is initialized (non-zero) or that 0 is the correct initialized value
+ * (mnt_throttle_mask is initialized and num_trailing_0 would be 0)
+ */
+ if (mp->mnt_devbsdunit || (mp->mnt_throttle_mask != LOWPRI_MAX_NUM_DEV - 1 && mp->mnt_throttle_mask & 0x1)) {
+ inflight = TRUE;
+ }
+ throttle_info = &_throttle_io_info[mp->mnt_devbsdunit];
+ } else {
+ throttle_info = &_throttle_io_info[LOWPRI_MAX_NUM_DEV - 1];
+ }
+
+ throttle_info_update_internal(throttle_info, ut, bflags, isssd, inflight, bap);
+
+ if ((bflags & B_READ) == 0) {
+ microuptime(&throttle_info->throttle_last_write_timestamp);
+
+ if (mp) {
+ mp->mnt_last_write_issued_timestamp = throttle_info->throttle_last_write_timestamp;
+ INCR_PENDING_IO(buf_count(bp), mp->mnt_pending_write_size);
+ }
+ } else if (mp) {
+ INCR_PENDING_IO(buf_count(bp), mp->mnt_pending_read_size);
+ }
+ /*
+ * The BootCache may give us special information about
+ * the IO, so it returns special values that we check
+ * for here.
+ *
+ * IO_SATISFIED_BY_CACHE
+ * The read has been satisfied by the boot cache. Don't
+ * throttle the thread unnecessarily.
+ *
+ * IO_SHOULD_BE_THROTTLED
+ * The boot cache is playing back a playlist and this IO
+ * cut through. Throttle it so we're not cutting through
+ * the boot cache too often.
+ *
+ * Note that typical strategy routines are defined with
+ * a void return so we'll get garbage here. In the
+ * unlikely case the garbage matches our special return
+ * value, it's not a big deal since we're only adjusting
+ * the throttling delay.
+ */
+#define IO_SATISFIED_BY_CACHE ((int)0xcafefeed)
+#define IO_SHOULD_BE_THROTTLED ((int)0xcafebeef)
+ typedef int strategy_fcn_ret_t(struct buf *bp);
+
+ strategy_ret = (*(strategy_fcn_ret_t*)bdevsw[major(bdev)].d_strategy)(bp);
+
+ // disk conditioner needs to track when this I/O actually starts
+ // which means track it after `strategy` which may include delays
+ // from inflight I/Os
+ microuptime(&bp->b_timestamp_tv);
+
+ if (IO_SATISFIED_BY_CACHE == strategy_ret) {
+ /*
+ * If this was a throttled IO satisfied by the boot cache,
+ * don't delay the thread.
+ */
+ throttle_info_reset_window(ut);
+ } else if (IO_SHOULD_BE_THROTTLED == strategy_ret) {
+ /*
+ * If the boot cache indicates this IO should be throttled,
+ * delay the thread.
+ */
+ throttle_info_set_initial_window(ut, throttle_info, TRUE, isssd);
+ }
+ return 0;
+}
+
+
+/*
+ * This is a noop, simply returning what one has been given.
+ */
+int
+spec_blockmap(__unused struct vnop_blockmap_args *ap)
+{
+ return ENOTSUP;
+}
+
+
+/*
+ * Device close routine
+ */
+int
+spec_close(struct vnop_close_args *ap)
+{
+ struct vnode *vp = ap->a_vp;
+ dev_t dev = vp->v_rdev;
+ int error = 0;
+ int flags = ap->a_fflag;
+ struct proc *p = vfs_context_proc(ap->a_context);
+ struct session *sessp;
+
+ switch (vp->v_type) {
+ case VCHR:
+ /*
+ * Hack: a tty device that is a controlling terminal
+ * has a reference from the session structure.
+ * We cannot easily tell that a character device is
+ * a controlling terminal, unless it is the closing
+ * process' controlling terminal. In that case,
+ * if the reference count is 1 (this is the very
+ * last close)
+ */
+ sessp = proc_session(p);
+ devsw_lock(dev, S_IFCHR);
+ if (sessp != SESSION_NULL) {
+ if (vp == sessp->s_ttyvp && vcount(vp) == 1) {
+ struct tty *tp = TTY_NULL;
+
+ devsw_unlock(dev, S_IFCHR);
+ session_lock(sessp);
+ if (vp == sessp->s_ttyvp) {
+ tp = SESSION_TP(sessp);
+ sessp->s_ttyvp = NULL;
+ sessp->s_ttyvid = 0;
+ sessp->s_ttyp = TTY_NULL;
+ sessp->s_ttypgrpid = NO_PID;
+ }
+ session_unlock(sessp);
+
+ if (tp != TTY_NULL) {
+ /*
+ * We may have won a race with a proc_exit
+ * of the session leader, the winner
+ * clears the flag (even if not set)
+ */
+ tty_lock(tp);
+ ttyclrpgrphup(tp);
+ tty_unlock(tp);
+
+ ttyfree(tp);
+ }
+ devsw_lock(dev, S_IFCHR);
+ }
+ session_rele(sessp);
+ }
+
+ if (--vp->v_specinfo->si_opencount < 0) {
+ panic("negative open count (c, %u, %u)", major(dev), minor(dev));
+ }
+
+ /*
+ * close on last reference or on vnode revoke call
+ */
+ if (vcount(vp) == 0 || (flags & IO_REVOKE) != 0) {
+ error = cdevsw[major(dev)].d_close(dev, flags, S_IFCHR, p);
+ }
+
+ devsw_unlock(dev, S_IFCHR);
+ break;
+
+ case VBLK:
+ /*
+ * If there is more than one outstanding open, don't
+ * send the close to the device.
+ */
+ devsw_lock(dev, S_IFBLK);
+ if (vcount(vp) > 1) {
+ vp->v_specinfo->si_opencount--;
+ devsw_unlock(dev, S_IFBLK);
+ return 0;
+ }
+ devsw_unlock(dev, S_IFBLK);
+
+ /*
+ * On last close of a block device (that isn't mounted)
+ * we must invalidate any in core blocks, so that
+ * we can, for instance, change floppy disks.
+ */
+ if ((error = spec_fsync_internal(vp, MNT_WAIT, ap->a_context))) {
+ return error;
+ }
+
+ error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0);
+ if (error) {
+ return error;
+ }
+
+ devsw_lock(dev, S_IFBLK);
+
+ if (--vp->v_specinfo->si_opencount < 0) {
+ panic("negative open count (b, %u, %u)", major(dev), minor(dev));
+ }
+
+ if (vcount(vp) == 0) {
+ error = bdevsw[major(dev)].d_close(dev, flags, S_IFBLK, p);
+ }
+
+ devsw_unlock(dev, S_IFBLK);
+ break;
+
+ default:
+ panic("spec_close: not special");
+ return EBADF;
+ }
+
+ return error;
+}
+
+/*
+ * Return POSIX pathconf information applicable to special devices.
+ */
+int
+spec_pathconf(struct vnop_pathconf_args *ap)
+{
+ switch (ap->a_name) {
+ case _PC_LINK_MAX:
+ *ap->a_retval = LINK_MAX;
+ return 0;
+ case _PC_MAX_CANON:
+ *ap->a_retval = MAX_CANON;
+ return 0;
+ case _PC_MAX_INPUT:
+ *ap->a_retval = MAX_INPUT;
+ return 0;
+ case _PC_PIPE_BUF:
+ *ap->a_retval = PIPE_BUF;
+ return 0;
+ case _PC_CHOWN_RESTRICTED:
+ *ap->a_retval = 200112; /* _POSIX_CHOWN_RESTRICTED */
+ return 0;
+ case _PC_VDISABLE:
+ *ap->a_retval = _POSIX_VDISABLE;
+ return 0;
+ default:
+ return EINVAL;
+ }
+ /* NOTREACHED */
+}
+
+/*
+ * Special device failed operation
+ */
+int
+spec_ebadf(__unused void *dummy)
+{
+ return EBADF;
}
/* Blktooff derives file offset from logical block number */
int
-spec_blktooff(ap)
- struct vnop_blktooff_args /* {
- struct vnode *a_vp;
- daddr64_t a_lblkno;
- off_t *a_offset;
- } */ *ap;
+spec_blktooff(struct vnop_blktooff_args *ap)
{
- register struct vnode *vp = ap->a_vp;
+ struct vnode *vp = ap->a_vp;
switch (vp->v_type) {
case VCHR:
*ap->a_offset = (off_t)-1; /* failure */
- return (ENOTSUP);
+ return ENOTSUP;
case VBLK:
printf("spec_blktooff: not implemented for VBLK\n");
*ap->a_offset = (off_t)-1; /* failure */
- return (ENOTSUP);
+ return ENOTSUP;
default:
panic("spec_blktooff type");
}
/* NOTREACHED */
- return (0);
+ return 0;
}
/* Offtoblk derives logical block number from file offset */
int
-spec_offtoblk(ap)
- struct vnop_offtoblk_args /* {
- struct vnode *a_vp;
- off_t a_offset;
- daddr64_t *a_lblkno;
- } */ *ap;
+spec_offtoblk(struct vnop_offtoblk_args *ap)
{
- register struct vnode *vp = ap->a_vp;
+ struct vnode *vp = ap->a_vp;
switch (vp->v_type) {
case VCHR:
*ap->a_lblkno = (daddr64_t)-1; /* failure */
- return (ENOTSUP);
+ return ENOTSUP;
case VBLK:
printf("spec_offtoblk: not implemented for VBLK\n");
*ap->a_lblkno = (daddr64_t)-1; /* failure */
- return (ENOTSUP);
+ return ENOTSUP;
default:
panic("spec_offtoblk type");
}
/* NOTREACHED */
- return (0);
+ return 0;
+}
+
+static void filt_specdetach(struct knote *kn);
+static int filt_specevent(struct knote *kn, long hint);
+static int filt_spectouch(struct knote *kn, struct kevent_qos_s *kev);
+static int filt_specprocess(struct knote *kn, struct kevent_qos_s *kev);
+static int filt_specpeek(struct knote *kn);
+
+SECURITY_READ_ONLY_EARLY(struct filterops) spec_filtops = {
+ .f_isfd = 1,
+ .f_attach = filt_specattach,
+ .f_detach = filt_specdetach,
+ .f_event = filt_specevent,
+ .f_touch = filt_spectouch,
+ .f_process = filt_specprocess,
+ .f_peek = filt_specpeek
+};
+
+
+/*
+ * Given a waitq that is assumed to be embedded within a selinfo structure,
+ * return the containing selinfo structure. While 'wq' is not really a queue
+ * element, this macro simply does the offset_of calculation to get back to a
+ * containing struct given the struct type and member name.
+ */
+#define selinfo_from_waitq(wq) \
+ qe_element((wq), struct selinfo, si_waitq)
+
+static int
+spec_knote_select_and_link(struct knote *kn)
+{
+ uthread_t uth;
+ vfs_context_t ctx;
+ vnode_t vp;
+ struct waitq_set *old_wqs;
+ uint64_t rsvd, rsvd_arg;
+ uint64_t *rlptr = NULL;
+ struct selinfo *si = NULL;
+ int selres = 0;
+
+ uth = get_bsdthread_info(current_thread());
+
+ ctx = vfs_context_current();
+ vp = (vnode_t)kn->kn_fp->f_fglob->fg_data;
+
+ int error = vnode_getwithvid(vp, vnode_vid(vp));
+ if (error != 0) {
+ knote_set_error(kn, ENOENT);
+ return 0;
+ }
+
+ /*
+ * This function may be called many times to link or re-link the
+ * underlying vnode to the kqueue. If we've already linked the two,
+ * we will have a valid kn_hook_waitqid which ties us to the underlying
+ * device's waitq via a the waitq's prepost table object. However,
+ * devices can abort any select action by calling selthreadclear().
+ * This is OK because the table object will be invalidated by the
+ * driver (through a call to selthreadclear), so any attempt to access
+ * the associated waitq will fail because the table object is invalid.
+ *
+ * Even if we've already registered, we need to pass a pointer
+ * to a reserved link structure. Otherwise, selrecord() will
+ * infer that we're in the second pass of select() and won't
+ * actually do anything!
+ */
+ rsvd = rsvd_arg = waitq_link_reserve(NULL);
+ rlptr = (void *)&rsvd_arg;
+
+ /*
+ * Trick selrecord() into hooking kqueue's wait queue set into the device's
+ * selinfo wait queue.
+ */
+ old_wqs = uth->uu_wqset;
+ uth->uu_wqset = &(knote_get_kq(kn)->kq_wqs);
+
+ /*
+ * Be sure that the waitq set is linked
+ * before calling select to avoid possible
+ * allocation under spinlocks.
+ */
+ waitq_set_lazy_init_link(uth->uu_wqset);
+
+ /*
+ * Now these are the laws of VNOP_SELECT, as old and as true as the sky,
+ * And the device that shall keep it may prosper, but the device that shall
+ * break it must receive ENODEV:
+ *
+ * 1. Take a lock to protect against other selects on the same vnode.
+ * 2. Return 1 if data is ready to be read.
+ * 3. Return 0 and call `selrecord` on a handy `selinfo` structure if there
+ * is no data.
+ * 4. Call `selwakeup` when the vnode has an active `selrecord` and data
+ * can be read or written (depending on the seltype).
+ * 5. If there's a `selrecord` and no corresponding `selwakeup`, but the
+ * vnode is going away, call `selthreadclear`.
+ */
+ selres = VNOP_SELECT(vp, knote_get_seltype(kn), 0, rlptr, ctx);
+ uth->uu_wqset = old_wqs;
+
+ /*
+ * Make sure to cleanup the reserved link - this guards against
+ * drivers that may not actually call selrecord().
+ */
+ waitq_link_release(rsvd);
+ if (rsvd != rsvd_arg) {
+ /* The driver / handler called selrecord() */
+ struct waitq *wq;
+ memcpy(&wq, rlptr, sizeof(void *));
+
+ /*
+ * The waitq is part of the selinfo structure managed by the
+ * driver. For certain drivers, we want to hook the knote into
+ * the selinfo structure's si_note field so selwakeup can call
+ * KNOTE.
+ */
+ si = selinfo_from_waitq(wq);
+
+ /*
+ * The waitq_get_prepost_id() function will (potentially)
+ * allocate a prepost table object for the waitq and return
+ * the table object's ID to us. It will also set the
+ * waitq_prepost_id field within the waitq structure.
+ *
+ * We can just overwrite kn_hook_waitqid because it's simply a
+ * table ID used to grab a reference when needed.
+ *
+ * We have a reference on the vnode, so we know that the
+ * device won't go away while we get this ID.
+ *
+ * Note: on 32bit this field is 32bit only.
+ */
+ kn->kn_hook_waitqid = (typeof(kn->kn_hook_waitqid))waitq_get_prepost_id(wq);
+ } else if (selres == 0) {
+ /*
+ * The device indicated that there's no data to read, but didn't call
+ * `selrecord`. Nothing will be notified of changes to this vnode, so
+ * return an error back to user space, to make it clear that the knote
+ * is not attached.
+ */
+ knote_set_error(kn, ENODEV);
+ }
+
+ vnode_put(vp);
+
+ return selres;
+}
+
+static int
+filt_spec_common(struct knote *kn, struct kevent_qos_s *kev, int selres)
+{
+ int64_t data;
+ int ret;
+
+ if (kn->kn_vnode_use_ofst) {
+ if (kn->kn_fp->f_fglob->fg_offset >= (uint32_t)selres) {
+ data = 0;
+ } else {
+ data = ((uint32_t)selres) - kn->kn_fp->f_fglob->fg_offset;
+ }
+ } else {
+ data = selres;
+ }
+
+ ret = data >= knote_low_watermark(kn);
+
+ if (ret && kev) {
+ knote_fill_kevent(kn, kev, data);
+ }
+
+ return ret;
+}
+
+static int
+filt_specattach(struct knote *kn, __unused struct kevent_qos_s *kev)
+{
+ vnode_t vp;
+ dev_t dev;
+
+ vp = (vnode_t)kn->kn_fp->f_fglob->fg_data; /* Already have iocount, and vnode is alive */
+
+ assert(vnode_ischr(vp));
+
+ dev = vnode_specrdev(vp);
+
+ /*
+ * For a few special kinds of devices, we can attach knotes with
+ * no restrictions because their "select" vectors return the amount
+ * of data available. Others require an explicit NOTE_LOWAT with
+ * data of 1, indicating that the caller doesn't care about actual
+ * data counts, just an indication that the device has data.
+ */
+ if (!kn->kn_vnode_kqok &&
+ ((kn->kn_sfflags & NOTE_LOWAT) == 0 || kn->kn_sdata != 1)) {
+ knote_set_error(kn, EINVAL);
+ return 0;
+ }
+
+ /*
+ * This forces the select fallback to call through VNOP_SELECT and hook
+ * up selinfo on every filter routine.
+ *
+ * Pseudo-terminal controllers are opted out of native kevent support --
+ * remove this when they get their own EVFILTID.
+ */
+ if (cdevsw_flags[major(dev)] & CDEVSW_IS_PTC) {
+ kn->kn_vnode_kqok = 0;
+ }
+
+ kn->kn_filtid = EVFILTID_SPEC;
+ kn->kn_hook_waitqid = 0;
+
+ knote_markstayactive(kn);
+ return spec_knote_select_and_link(kn);
+}
+
+static void
+filt_specdetach(struct knote *kn)
+{
+ knote_clearstayactive(kn);
+
+ /*
+ * This is potentially tricky: the device's selinfo waitq that was
+ * tricked into being part of this knote's waitq set may not be a part
+ * of any other set, and the device itself may have revoked the memory
+ * in which the waitq was held. We use the knote's kn_hook_waitqid field
+ * to keep the ID of the waitq's prepost table object. This
+ * object keeps a pointer back to the waitq, and gives us a safe way
+ * to decouple the dereferencing of driver allocated memory: if the
+ * driver goes away (taking the waitq with it) then the prepost table
+ * object will be invalidated. The waitq details are handled in the
+ * waitq API invoked here.
+ */
+ if (kn->kn_hook_waitqid) {
+ waitq_unlink_by_prepost_id(kn->kn_hook_waitqid, &(knote_get_kq(kn)->kq_wqs));
+ kn->kn_hook_waitqid = 0;
+ }
+}
+
+static int
+filt_specevent(struct knote *kn, __unused long hint)
+{
+ /*
+ * Nothing should call knote or knote_vanish on this knote.
+ */
+ panic("filt_specevent(%p)", kn);
+ return 0;
+}
+
+static int
+filt_spectouch(struct knote *kn, struct kevent_qos_s *kev)
+{
+ kn->kn_sdata = kev->data;
+ kn->kn_sfflags = kev->fflags;
+
+ if (kev->flags & EV_ENABLE) {
+ return spec_knote_select_and_link(kn);
+ }
+
+ return 0;
+}
+
+static int
+filt_specprocess(struct knote *kn, struct kevent_qos_s *kev)
+{
+ vnode_t vp;
+ uthread_t uth;
+ vfs_context_t ctx;
+ int res;
+ int selres;
+ int error;
+
+ uth = get_bsdthread_info(current_thread());
+ ctx = vfs_context_current();
+ vp = (vnode_t)kn->kn_fp->f_fglob->fg_data;
+
+ error = vnode_getwithvid(vp, vnode_vid(vp));
+ if (error != 0) {
+ kn->kn_flags |= (EV_EOF | EV_ONESHOT);
+ knote_fill_kevent(kn, kev, 0);
+ return 1;
+ }
+
+ selres = spec_knote_select_and_link(kn);
+ res = filt_spec_common(kn, kev, selres);
+
+ vnode_put(vp);
+
+ return res;
+}
+
+static int
+filt_specpeek(struct knote *kn)
+{
+ int selres = 0;
+
+ selres = spec_knote_select_and_link(kn);
+ return filt_spec_common(kn, NULL, selres);
}