/* * Copyright (c) 2000-2012 Apple Computer, Inc. All rights reserved. * * @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, 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 */ /* * Copyright (c) 1989, 1993, 1995 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)spec_vnops.c 8.14 (Berkeley) 5/21/95 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* 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 dev, struct knote *kn); extern int ignore_is_ssd; 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"; #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 } }; struct vnodeopv_desc spec_vnodeop_opv_desc = { &spec_vnodeop_p, 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 15 #define LOWPRI_TIER2_IO_PERIOD_MSECS 50 #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]; 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]; 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; }; struct _throttle_io_info_t _throttle_io_info[LOWPRI_MAX_NUM_DEV]; int lowpri_throttle_enabled = 1; static void throttle_info_update_internal(struct _throttle_io_info_t *info, uthread_t ut, int flags, boolean_t isssd); static int throttle_get_thread_throttle_level(uthread_t ut); /* * Trivial lookup routine that always fails. */ int spec_lookup(struct vnop_lookup_args *ap) { *ap->a_vpp = NULL; return (ENOTDIR); } static void set_blocksize(struct vnode *vp, dev_t dev) { 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; } 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) return; vnode_lock(vp); set_blocksize(vp, dev); vnode_unlock(vp); } } /* * Open a special file. */ int 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); struct vnode *vp = ap->a_vp; dev_t bdev, dev = (dev_t)vp->v_rdev; int maj = major(dev); int error; /* * Don't allow open if fs is mounted -nodev. */ 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 (cred != FSCRED && (ap->a_mode & FWRITE)) { /* * 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); /* 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 character devices whose corresponding block * devices are currently mounted. */ if (securelevel >= 1) { if ((bdev = chrtoblk(dev)) != NODEV && check_mountedon(bdev, VBLK, &error)) return (error); } } devsw_lock(dev, S_IFCHR); error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, p); 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); /* * 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); /* * Do not allow opens of block devices that are * currently mounted. */ 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) { 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)) { /* 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)) { 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; } vnode_lock(vp); set_blocksize(vp, dev); /* * 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 */ vnode_unlock(vp); } return(error); default: panic("spec_open type"); } return (0); } /* * Vnode op for read */ int 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 n, on; int error = 0; dev_t dev; #if DIAGNOSTIC if (uio->uio_rw != UIO_READ) panic("spec_read mode"); if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) panic("spec_read proc"); #endif if (uio_resid(uio) == 0) return (0); switch (vp->v_type) { case VCHR: if (cdevsw[major(vp->v_rdev)].d_type == D_DISK && vp->v_un.vu_specinfo->si_throttleable) { struct _throttle_io_info_t *throttle_info; throttle_info = &_throttle_io_info[vp->v_un.vu_specinfo->si_devbsdunit]; throttle_info_update_internal(throttle_info, NULL, 0, vp->v_un.vu_specinfo->si_isssd); } error = (*cdevsw[major(vp->v_rdev)].d_read) (vp->v_rdev, uio, ap->a_ioflag); return (error); case VBLK: if (uio->uio_offset < 0) return (EINVAL); dev = vp->v_rdev; devBlockSize = vp->v_specsize; if (devBlockSize > PAGE_SIZE) return (EINVAL); bscale = PAGE_SIZE / devBlockSize; bsize = bscale * devBlockSize; do { on = uio->uio_offset % bsize; bn = (daddr64_t)((uio->uio_offset / devBlockSize) &~ (bscale - 1)); if (vp->v_speclastr + bscale == bn) { 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); vnode_lock(vp); vp->v_speclastr = bn; vnode_unlock(vp); n = bsize - buf_resid(bp); if ((on > n) || error) { if (!error) error = EINVAL; buf_brelse(bp); return (error); } n = min((unsigned)(n - on), uio_resid(uio)); error = uiomove((char *)buf_dataptr(bp) + on, n, uio); if (n + on == bsize) buf_markaged(bp); buf_brelse(bp); } while (error == 0 && uio_resid(uio) > 0 && n != 0); return (error); default: panic("spec_read type"); } /* NOTREACHED */ return (0); } /* * Vnode op for write */ int 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; int io_sync; int devBlockSize=0; int n, on; int error = 0; dev_t dev; #if DIAGNOSTIC if (uio->uio_rw != UIO_WRITE) panic("spec_write mode"); if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) panic("spec_write proc"); #endif switch (vp->v_type) { case VCHR: if (cdevsw[major(vp->v_rdev)].d_type == D_DISK && vp->v_un.vu_specinfo->si_throttleable) { struct _throttle_io_info_t *throttle_info; throttle_info = &_throttle_io_info[vp->v_un.vu_specinfo->si_devbsdunit]; throttle_info_update_internal(throttle_info, NULL, 0, vp->v_un.vu_specinfo->si_isssd); microuptime(&throttle_info->throttle_last_write_timestamp); } error = (*cdevsw[major(vp->v_rdev)].d_write) (vp->v_rdev, uio, ap->a_ioflag); return (error); case VBLK: if (uio_resid(uio) == 0) return (0); if (uio->uio_offset < 0) return (EINVAL); io_sync = (ap->a_ioflag & IO_SYNC); dev = (vp->v_rdev); devBlockSize = vp->v_specsize; if (devBlockSize > PAGE_SIZE) return(EINVAL); bscale = PAGE_SIZE / devBlockSize; blkmask = bscale - 1; bsize = bscale * devBlockSize; do { bn = (daddr64_t)((uio->uio_offset / devBlockSize) &~ blkmask); on = uio->uio_offset % bsize; n = min((unsigned)(bsize - on), uio_resid(uio)); /* * Use buf_getblk() as an optimization IFF: * * 1) We are reading exactly a block on a block * aligned boundary * 2) We know the size of the device from spec_open * 3) The read doesn't span the end of the device * * Otherwise, we fall back on buf_bread(). */ 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; } 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) error = (int)buf_error(bp); if (error) { buf_brelse(bp); 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); } buf_markaged(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); default: panic("spec_write type"); } /* NOTREACHED */ return (0); } /* * Device ioctl operation. */ int 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; KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_IOCTL, 0) | DBG_FUNC_START, (unsigned int)dev, (unsigned int)ap->a_command, (unsigned int)ap->a_fflag, (unsigned int)ap->a_vp->v_type, 0); switch (ap->a_vp->v_type) { case VCHR: retval = (*cdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, ap->a_fflag, p); break; case VBLK: if (kdebug_enable) { if (ap->a_command == DKIOCUNMAP) { dk_unmap_t *unmap; dk_extent_t *extent; uint32_t i; unmap = (dk_unmap_t *)ap->a_data; extent = unmap->extents; for (i = 0; i < unmap->extentsCount; i++, extent++) { KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_IOCTL, 1) | DBG_FUNC_NONE, dev, extent->offset/ap->a_vp->v_specsize, extent->length, 0, 0); } } } retval = (*bdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, ap->a_fflag, p); break; default: panic("spec_ioctl"); /* NOTREACHED */ } KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_IOCTL, 0) | DBG_FUNC_END, (unsigned int)dev, (unsigned int)ap->a_command, (unsigned int)ap->a_fflag, retval, 0); return (retval); } int spec_select(struct vnop_select_args *ap) { proc_t p = vfs_context_proc(ap->a_context); dev_t dev; switch (ap->a_vp->v_type) { default: return (1); /* XXX */ case VCHR: dev = ap->a_vp->v_rdev; return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_wql, p); } } static int filt_specattach(struct knote *kn); int spec_kqfilter(vnode_t vp, struct knote *kn) { dev_t dev; int err = EINVAL; /* * For a few special kinds of devices, we can attach knotes. * Each filter function must check whether the dev type matches it. */ dev = vnode_specrdev(vp); if (vnode_istty(vp)) { /* We can hook into TTYs... */ err = filt_specattach(kn); } else { #if NETWORKING /* Try a bpf device, as defined in bsd/net/bpf.c */ err = bpfkqfilter(dev, kn); #endif } return err; } /* * 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); /* * Flush all dirty buffers associated with a block device. */ buf_flushdirtyblks(vp, (waitfor == MNT_WAIT || waitfor == MNT_DWAIT), 0, "spec_fsync"); return (0); } int 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 */ void throttle_init(void); #if 0 #define DEBUG_ALLOC_THROTTLE_INFO(format, debug_info, args...) \ do { \ if ((debug_info)->alloc) \ printf("%s: "format, __FUNCTION__, ## args); \ } while(0) #else #define DEBUG_ALLOC_THROTTLE_INFO(format, debug_info, args...) #endif 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, ""); 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, ""); 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, ""); SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_enabled, CTLFLAG_RW | CTLFLAG_LOCKED, &lowpri_throttle_enabled, 0, ""); static lck_grp_t *throttle_mtx_grp; static lck_attr_t *throttle_mtx_attr; static lck_grp_attr_t *throttle_mtx_grp_attr; /* * throttled I/O helper function * convert the index of the lowest set bit to a device index */ int num_trailing_0(uint64_t n) { /* * 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; } /* * 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. */ static int throttle_info_rel(struct _throttle_io_info_t *info) { SInt32 oldValue = OSDecrementAtomic(&info->throttle_refcnt); DEBUG_ALLOC_THROTTLE_INFO("refcnt = %d info = %p\n", info, (int)(oldValue -1), info ); /* The reference count just went negative, very bad */ if (oldValue == 0) panic("throttle info ref cnt went negative!"); /* * 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); lck_mtx_destroy(&info->throttle_lock, throttle_mtx_grp); FREE(info, M_TEMP); } return oldValue; } /* * Just take a reference on the throttle info structure. * * This routine always returns the old value. */ static SInt32 throttle_info_ref(struct _throttle_io_info_t *info) { SInt32 oldValue = OSIncrementAtomic(&info->throttle_refcnt); 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"); return oldValue; } /* * 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 */ 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; info->throttle_min_timer_deadline = now; msecs = info->throttle_io_periods[THROTTLE_LEVEL_THROTTLED]; period.tv_sec = msecs / 1000; period.tv_usec = (msecs % 1000) * 1000; 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]) { /* * 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; 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; 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_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_mtx_grp_attr = lck_grp_attr_alloc_init(); throttle_mtx_grp = lck_grp_alloc_init("throttle I/O", throttle_mtx_grp_attr); /* Update throttle parameters based on device tree configuration */ throttle_init_throttle_window(); /* * allocate the lock attribute */ throttle_mtx_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_mtx_grp, throttle_mtx_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_next_wake_level = THROTTLE_LEVEL_END; info->throttle_disabled = 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(int flag) { if (flag == THROTTLE_IO_ENABLE) lowpri_throttle_enabled = 1; if (flag == THROTTLE_IO_DISABLE) lowpri_throttle_enabled = 0; } int rethrottle_removed_from_list = 0; int rethrottle_moved_to_new_list = 0; /* * move a throttled thread to the appropriate state based * on it's new throttle level... throttle_add_to_list will * reset the timer deadline if necessary... it may also * leave the thread off of the queue if we're already outside * the throttle window for the new level * takes a valid uthread (which may or may not be on the * throttle queue) as input * * NOTE: This is called with the task lock held. */ void rethrottle_thread(uthread_t ut) { struct _throttle_io_info_t *info; int my_new_level; if ((info = ut->uu_throttle_info) == NULL) return; lck_mtx_lock(&info->throttle_lock); if (ut->uu_on_throttlelist >= THROTTLE_LEVEL_THROTTLED) { my_new_level = throttle_get_thread_throttle_level(ut); if (my_new_level != ut->uu_on_throttlelist) { TAILQ_REMOVE(&info->throttle_uthlist[ut->uu_on_throttlelist], ut, uu_throttlelist); ut->uu_on_throttlelist = THROTTLE_LEVEL_NONE; if (my_new_level >= THROTTLE_LEVEL_THROTTLED) { throttle_add_to_list(info, ut, my_new_level, TRUE); rethrottle_moved_to_new_list++; } /* Thread no longer in window, need to wake it up */ if (ut->uu_on_throttlelist == THROTTLE_LEVEL_NONE) { wakeup(&ut->uu_on_throttlelist); rethrottle_removed_from_list++; } } } lck_mtx_unlock(&info->throttle_lock); } /* * 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_mtx_grp, throttle_mtx_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; } 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) { int thread_throttle_level; if (ut == NULL) ut = get_bsdthread_info(current_thread()); thread_throttle_level = proc_get_effective_thread_policy(ut->uu_thread, TASK_POLICY_IO); /* Bootcache misses should always be throttled */ if (ut->uu_throttle_bc == TRUE) thread_throttle_level = THROTTLE_LEVEL_TIER3; return (thread_throttle_level); } 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; 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); for (throttle_level = THROTTLE_LEVEL_START; throttle_level < thread_throttle_level; throttle_level++) { 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 * 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_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; 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); if (sleep_amount == 0) goto done; if (sleep_amount == 1 && ut->uu_throttle_bc == FALSE) sleep_amount = 0; throttle_io_period_num = info->throttle_io_period_num; 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; } 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); 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]++; } msleep((caddr_t)&ut->uu_on_throttlelist, &info->throttle_lock, PRIBIO + 1, "throttle_lowpri_io", NULL); 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); } throttle_info_rel(info); ut->uu_throttle_info = NULL; ut->uu_throttle_bc = FALSE; ut->uu_lowpri_window = 0; return (sleep_cnt); } /* * 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_task_policy(current_task(), current_thread(), TASK_POLICY_INTERNAL, TASK_POLICY_IOPOL, policy); } void throttle_info_reset_window(uthread_t ut) { struct _throttle_io_info_t *info; 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; } } static void throttle_info_update_internal(struct _throttle_io_info_t *info, uthread_t ut, int flags, boolean_t isssd) { int thread_throttle_level; if (lowpri_throttle_enabled == 0 || info->throttle_disabled) return; if (ut == NULL) ut = get_bsdthread_info(current_thread()); thread_throttle_level = throttle_get_thread_throttle_level(ut); if (thread_throttle_level != THROTTLE_LEVEL_NONE) { if(!ISSET(flags, B_PASSIVE)) { microuptime(&info->throttle_window_start_timestamp[thread_throttle_level]); info->throttle_last_IO_pid[thread_throttle_level] = proc_selfpid(); 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); } } 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 ((mp->mnt_kern_flag & MNTK_SSD) && !ignore_is_ssd) 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); } /* * 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) { 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]; info->throttle_disabled = 1; 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++) { 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 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; int code = 0; proc_t curproc = current_proc(); bp = ap->a_bp; bdev = buf_device(bp); mp = buf_vnode(bp)->v_mount; bap = &bp->b_attr; io_tier = throttle_get_io_policy(&ut); passive = throttle_get_passive_io_policy(&ut); 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)) { 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 ((curproc != NULL) && ((curproc->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP)) bap->ba_flags |= BA_DELAYIDLESLEEP; 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 (bflags & B_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 (kdebug_enable) { KERNEL_DEBUG_CONSTANT_IST(KDEBUG_COMMON, FSDBG_CODE(DBG_DKRW, code) | DBG_FUNC_NONE, buf_kernel_addrperm_addr(bp), bdev, (int)buf_blkno(bp), buf_count(bp), 0); } thread_update_io_stats(current_thread(), buf_count(bp), code); if (mp != NULL) { if ((mp->mnt_kern_flag & MNTK_SSD) && !ignore_is_ssd) isssd = 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); 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); 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(struct vnop_blktooff_args *ap) { struct vnode *vp = ap->a_vp; switch (vp->v_type) { case VCHR: *ap->a_offset = (off_t)-1; /* failure */ return (ENOTSUP); case VBLK: printf("spec_blktooff: not implemented for VBLK\n"); *ap->a_offset = (off_t)-1; /* failure */ return (ENOTSUP); default: panic("spec_blktooff type"); } /* NOTREACHED */ return (0); } /* Offtoblk derives logical block number from file offset */ int spec_offtoblk(struct vnop_offtoblk_args *ap) { struct vnode *vp = ap->a_vp; switch (vp->v_type) { case VCHR: *ap->a_lblkno = (daddr64_t)-1; /* failure */ return (ENOTSUP); case VBLK: printf("spec_offtoblk: not implemented for VBLK\n"); *ap->a_lblkno = (daddr64_t)-1; /* failure */ return (ENOTSUP); default: panic("spec_offtoblk type"); } /* NOTREACHED */ return (0); } static void filt_specdetach(struct knote *kn); static int filt_spec(struct knote *kn, long hint); static unsigned filt_specpeek(struct knote *kn); struct filterops spec_filtops = { .f_isfd = 1, .f_attach = filt_specattach, .f_detach = filt_specdetach, .f_event = filt_spec, .f_peek = filt_specpeek }; static int filter_to_seltype(int16_t filter) { switch (filter) { case EVFILT_READ: return FREAD; case EVFILT_WRITE: return FWRITE; break; default: panic("filt_to_seltype(): invalid filter %d\n", filter); return 0; } } static int filt_specattach(struct knote *kn) { 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); if (major(dev) > nchrdev) { return ENXIO; } if ((cdevsw_flags[major(dev)] & CDEVSW_SELECT_KQUEUE) == 0) { return EINVAL; } /* Resulting wql is safe to unlink even if it has never been linked */ kn->kn_hook = wait_queue_link_allocate(); if (kn->kn_hook == NULL) { return EAGAIN; } kn->kn_fop = &spec_filtops; kn->kn_hookid = vnode_vid(vp); knote_markstayqueued(kn); return 0; } static void filt_specdetach(struct knote *kn) { kern_return_t ret; /* * Given wait queue link and wait queue set, unlink. This is subtle. * If the device has been revoked from under us, selclearthread() will * have removed our link from the kqueue's wait queue set, which * wait_queue_set_unlink_one() will detect and handle. */ ret = wait_queue_set_unlink_one(kn->kn_kq->kq_wqs, kn->kn_hook); if (ret != KERN_SUCCESS) { panic("filt_specdetach(): failed to unlink wait queue link."); } (void)wait_queue_link_free(kn->kn_hook); kn->kn_hook = NULL; kn->kn_status &= ~KN_STAYQUEUED; } static int filt_spec(struct knote *kn, long hint) { vnode_t vp; uthread_t uth; wait_queue_set_t old_wqs; vfs_context_t ctx; int selres; int error; int use_offset; dev_t dev; uint64_t flags; assert(kn->kn_hook != NULL); if (hint != 0) { panic("filt_spec(): nonzero hint?"); } uth = get_bsdthread_info(current_thread()); ctx = vfs_context_current(); vp = (vnode_t)kn->kn_fp->f_fglob->fg_data; error = vnode_getwithvid(vp, kn->kn_hookid); if (error != 0) { kn->kn_flags |= (EV_EOF | EV_ONESHOT); return 1; } dev = vnode_specrdev(vp); flags = cdevsw_flags[major(dev)]; use_offset = ((flags & CDEVSW_USE_OFFSET) != 0); assert((flags & CDEVSW_SELECT_KQUEUE) != 0); /* Trick selrecord() into hooking kqueue's wait queue set into device wait queue */ old_wqs = uth->uu_wqset; uth->uu_wqset = kn->kn_kq->kq_wqs; selres = VNOP_SELECT(vp, filter_to_seltype(kn->kn_filter), 0, kn->kn_hook, ctx); uth->uu_wqset = old_wqs; if (use_offset) { if (kn->kn_fp->f_fglob->fg_offset >= (uint32_t)selres) { kn->kn_data = 0; } else { kn->kn_data = ((uint32_t)selres) - kn->kn_fp->f_fglob->fg_offset; } } else { kn->kn_data = selres; } vnode_put(vp); return (kn->kn_data != 0); } static unsigned filt_specpeek(struct knote *kn) { vnode_t vp; uthread_t uth; wait_queue_set_t old_wqs; vfs_context_t ctx; int error, selres; uth = get_bsdthread_info(current_thread()); ctx = vfs_context_current(); vp = (vnode_t)kn->kn_fp->f_fglob->fg_data; error = vnode_getwithvid(vp, kn->kn_hookid); if (error != 0) { return 1; /* Just like VNOP_SELECT() on recycled vnode */ } /* * Why pass the link here? Because we may not have registered in the past... */ old_wqs = uth->uu_wqset; uth->uu_wqset = kn->kn_kq->kq_wqs; selres = VNOP_SELECT(vp, filter_to_seltype(kn->kn_filter), 0, kn->kn_hook, ctx); uth->uu_wqset = old_wqs; vnode_put(vp); return selres; }