X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/fa4905b191e0d16b0fffd53bd565eca71d01fae0..a39ff7e25e19b3a8c3020042a3872ca9ec9659f1:/bsd/miscfs/specfs/spec_vnops.c diff --git a/bsd/miscfs/specfs/spec_vnops.c b/bsd/miscfs/specfs/spec_vnops.c index 81b836085..6e0c09d1c 100644 --- a/bsd/miscfs/specfs/spec_vnops.c +++ b/bsd/miscfs/specfs/spec_vnops.c @@ -1,23 +1,29 @@ /* - * Copyright (c) 2000-2001 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2016 Apple Computer, Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_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 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. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * 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. + * 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_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */ /* @@ -56,23 +62,49 @@ */ #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 #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, struct knote *); +extern int ptmx_kqfilter(dev_t, struct knote *); struct vnode *speclisth[SPECHSZ]; @@ -89,81 +121,143 @@ char devcls[] = "devcls"; int (**spec_vnodeop_p)(void *); struct vnodeopv_entry_desc spec_vnodeop_entries[] = { - { &vop_default_desc, (VOPFUNC)vn_default_error }, - { &vop_lookup_desc, (VOPFUNC)spec_lookup }, /* lookup */ - { &vop_create_desc, (VOPFUNC)err_create }, /* create */ - { &vop_mknod_desc, (VOPFUNC)err_mknod }, /* mknod */ - { &vop_open_desc, (VOPFUNC)spec_open }, /* open */ - { &vop_close_desc, (VOPFUNC)spec_close }, /* close */ - { &vop_access_desc, (VOPFUNC)spec_access }, /* access */ - { &vop_getattr_desc, (VOPFUNC)spec_getattr }, /* getattr */ - { &vop_setattr_desc, (VOPFUNC)spec_setattr }, /* setattr */ - { &vop_read_desc, (VOPFUNC)spec_read }, /* read */ - { &vop_write_desc, (VOPFUNC)spec_write }, /* write */ - { &vop_lease_desc, (VOPFUNC)nop_lease }, /* lease */ - { &vop_ioctl_desc, (VOPFUNC)spec_ioctl }, /* ioctl */ - { &vop_select_desc, (VOPFUNC)spec_select }, /* select */ - { &vop_revoke_desc, (VOPFUNC)nop_revoke }, /* revoke */ - { &vop_mmap_desc, (VOPFUNC)err_mmap }, /* mmap */ - { &vop_fsync_desc, (VOPFUNC)spec_fsync }, /* fsync */ - { &vop_seek_desc, (VOPFUNC)err_seek }, /* seek */ - { &vop_remove_desc, (VOPFUNC)err_remove }, /* remove */ - { &vop_link_desc, (VOPFUNC)err_link }, /* link */ - { &vop_rename_desc, (VOPFUNC)err_rename }, /* rename */ - { &vop_mkdir_desc, (VOPFUNC)err_mkdir }, /* mkdir */ - { &vop_rmdir_desc, (VOPFUNC)err_rmdir }, /* rmdir */ - { &vop_symlink_desc, (VOPFUNC)err_symlink }, /* symlink */ - { &vop_readdir_desc, (VOPFUNC)err_readdir }, /* readdir */ - { &vop_readlink_desc, (VOPFUNC)err_readlink }, /* readlink */ - { &vop_abortop_desc, (VOPFUNC)err_abortop }, /* abortop */ - { &vop_inactive_desc, (VOPFUNC)nop_inactive }, /* inactive */ - { &vop_reclaim_desc, (VOPFUNC)nop_reclaim }, /* reclaim */ - { &vop_lock_desc, (VOPFUNC)nop_lock }, /* lock */ - { &vop_unlock_desc, (VOPFUNC)nop_unlock }, /* unlock */ - { &vop_bmap_desc, (VOPFUNC)spec_bmap }, /* bmap */ - { &vop_strategy_desc, (VOPFUNC)spec_strategy }, /* strategy */ - { &vop_print_desc, (VOPFUNC)spec_print }, /* print */ - { &vop_islocked_desc, (VOPFUNC)nop_islocked }, /* islocked */ - { &vop_pathconf_desc, (VOPFUNC)spec_pathconf }, /* pathconf */ - { &vop_advlock_desc, (VOPFUNC)err_advlock }, /* advlock */ - { &vop_blkatoff_desc, (VOPFUNC)err_blkatoff }, /* blkatoff */ - { &vop_valloc_desc, (VOPFUNC)err_valloc }, /* valloc */ - { &vop_vfree_desc, (VOPFUNC)err_vfree }, /* vfree */ - { &vop_truncate_desc, (VOPFUNC)nop_truncate }, /* truncate */ - { &vop_update_desc, (VOPFUNC)nop_update }, /* update */ - { &vop_bwrite_desc, (VOPFUNC)spec_bwrite }, /* bwrite */ - { &vop_devblocksize_desc, (VOPFUNC)spec_devblocksize }, /* devblocksize */ - { &vop_pagein_desc, (VOPFUNC)err_pagein }, /* Pagein */ - { &vop_pageout_desc, (VOPFUNC)err_pageout }, /* Pageout */ - { &vop_copyfile_desc, (VOPFUNC)err_copyfile }, /* Copyfile */ - { &vop_blktooff_desc, (VOPFUNC)spec_blktooff }, /* blktooff */ - { &vop_offtoblk_desc, (VOPFUNC)spec_offtoblk }, /* offtoblk */ - { &vop_cmap_desc, (VOPFUNC)spec_cmap }, /* cmap */ - { (struct vnodeop_desc*)NULL, (int(*)())NULL } + { &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(*)(void *))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 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 vop_lookup_args /* { - struct vnode *a_dvp; - struct vnode **a_vpp; - struct componentname *a_cnp; - } */ *ap; +spec_lookup(struct vnop_lookup_args *ap) { *ap->a_vpp = NULL; return (ENOTDIR); } -void +static void set_blocksize(struct vnode *vp, dev_t dev) { - int (*size)(); + int (*size)(dev_t); int rsize; if ((major(dev) < nblkdev) && (size = bdevsw[major(dev)].d_psize)) { @@ -185,10 +279,12 @@ set_fsblocksize(struct vnode *vp) dev_t dev = (dev_t)vp->v_rdev; int maj = major(dev); - if ((u_int)maj >= nblkdev) + if ((u_int)maj >= (u_int)nblkdev) return; + vnode_lock(vp); set_blocksize(vp, dev); + vnode_unlock(vp); } } @@ -197,17 +293,12 @@ set_fsblocksize(struct vnode *vp) /* * Open a special file. */ -/* ARGSUSED */ -spec_open(ap) - struct vop_open_args /* { - struct vnode *a_vp; - int a_mode; - struct ucred *a_cred; - struct proc *a_p; - } */ *ap; -{ - struct proc *p = ap->a_p; - struct vnode *bvp, *vp = ap->a_vp; +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; @@ -221,59 +312,137 @@ spec_open(ap) switch (vp->v_type) { case VCHR: - if ((u_int)maj >= nchrdev) + if ((u_int)maj >= (u_int)nchrdev) return (ENXIO); - if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { + 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 /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 && - vfinddev(bdev, VBLK, &bvp) && - bvp->v_usecount > 0 && - (error = vfs_mountedon(bvp))) + if ((bdev = chrtoblk(dev)) != NODEV && check_mountedon(bdev, VBLK, &error)) return (error); - if (iskmemdev(dev)) - return (EPERM); } } - if (cdevsw[maj].d_type == D_TTY) - vp->v_flag |= VISTTY; - VOP_UNLOCK(vp, 0, p); + + devsw_lock(dev, S_IFCHR); error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, p); - vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, 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 >= nblkdev) + 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 && ap->a_cred != FSCRED && + 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)) + 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); } @@ -281,43 +450,47 @@ spec_open(ap) /* * Vnode op for read */ -/* ARGSUSED */ -spec_read(ap) - struct vop_read_args /* { - struct vnode *a_vp; - struct uio *a_uio; - int a_ioflag; - struct ucred *a_cred; - } */ *ap; -{ - register struct vnode *vp = ap->a_vp; - register struct uio *uio = ap->a_uio; - struct proc *p = uio->uio_procp; +int +spec_read(struct vnop_read_args *ap) +{ + struct vnode *vp = ap->a_vp; + struct uio *uio = ap->a_uio; struct buf *bp; - daddr_t bn, nextbn; + daddr64_t bn, nextbn; long bsize, bscale; int devBlockSize=0; - int n, on, majordev, (*ioctl)(); + int n, on; int error = 0; dev_t dev; #if DIAGNOSTIC if (uio->uio_rw != UIO_READ) panic("spec_read mode"); - if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != current_proc()) + if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) panic("spec_read proc"); #endif - if (uio->uio_resid == 0) + if (uio_resid(uio) == 0) return (0); switch (vp->v_type) { case VCHR: - VOP_UNLOCK(vp, 0, p); + { + struct _throttle_io_info_t *throttle_info = NULL; + int thread_throttle_level; + if (cdevsw[major(vp->v_rdev)].d_type == D_DISK && 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); + } error = (*cdevsw[major(vp->v_rdev)].d_read) (vp->v_rdev, uio, ap->a_ioflag); - vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); + + if (throttle_info) { + throttle_info_end_io_internal(throttle_info, thread_throttle_level); + } + return (error); + } case VBLK: if (uio->uio_offset < 0) @@ -336,87 +509,97 @@ spec_read(ap) do { on = uio->uio_offset % bsize; - bn = (uio->uio_offset / devBlockSize) &~ (bscale - 1); + bn = (daddr64_t)((uio->uio_offset / devBlockSize) &~ (bscale - 1)); - if (vp->v_lastr + bscale == bn) { + if (vp->v_speclastr + bscale == bn) { nextbn = bn + bscale; - error = breadn(vp, bn, (int)bsize, &nextbn, + error = buf_breadn(vp, bn, (int)bsize, &nextbn, (int *)&bsize, 1, NOCRED, &bp); } else - error = bread(vp, bn, (int)bsize, NOCRED, &bp); + error = buf_bread(vp, bn, (int)bsize, NOCRED, &bp); - vp->v_lastr = bn; - n = bsize - bp->b_resid; + vnode_lock(vp); + vp->v_speclastr = bn; + vnode_unlock(vp); + + n = bsize - buf_resid(bp); if ((on > n) || error) { if (!error) error = EINVAL; - brelse(bp); + buf_brelse(bp); return (error); } - n = min((unsigned)(n - on), uio->uio_resid); + n = min((unsigned)(n - on), uio_resid(uio)); - error = uiomove((char *)bp->b_data + on, n, uio); + error = uiomove((char *)buf_dataptr(bp) + on, n, uio); if (n + on == bsize) - bp->b_flags |= B_AGE; - brelse(bp); - } while (error == 0 && uio->uio_resid > 0 && n != 0); + 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 */ -/* ARGSUSED */ -spec_write(ap) - struct vop_write_args /* { - struct vnode *a_vp; - struct uio *a_uio; - int a_ioflag; - struct ucred *a_cred; - } */ *ap; -{ - register struct vnode *vp = ap->a_vp; - register struct uio *uio = ap->a_uio; - struct proc *p = uio->uio_procp; +int +spec_write(struct vnop_write_args *ap) +{ + struct vnode *vp = ap->a_vp; + struct uio *uio = ap->a_uio; struct buf *bp; - daddr_t bn; + daddr64_t bn; int bsize, blkmask, bscale; - register int io_sync; - register int io_size; + int io_sync; int devBlockSize=0; - register int n, on; + int n, on; int error = 0; dev_t dev; #if DIAGNOSTIC if (uio->uio_rw != UIO_WRITE) panic("spec_write mode"); - if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != current_proc()) + if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) panic("spec_write proc"); #endif switch (vp->v_type) { case VCHR: - VOP_UNLOCK(vp, 0, p); + { + struct _throttle_io_info_t *throttle_info = NULL; + int thread_throttle_level; + if (cdevsw[major(vp->v_rdev)].d_type == D_DISK && 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); + } error = (*cdevsw[major(vp->v_rdev)].d_write) (vp->v_rdev, uio, ap->a_ioflag); - vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); + + if (throttle_info) { + throttle_info_end_io_internal(throttle_info, thread_throttle_level); + } + return (error); + } case VBLK: - if (uio->uio_resid == 0) + if (uio_resid(uio) == 0) return (0); if (uio->uio_offset < 0) return (EINVAL); io_sync = (ap->a_ioflag & IO_SYNC); - io_size = uio->uio_resid; dev = (vp->v_rdev); @@ -430,92 +613,109 @@ spec_write(ap) do { - bn = (uio->uio_offset / devBlockSize) &~ blkmask; + bn = (daddr64_t)((uio->uio_offset / devBlockSize) &~ blkmask); on = uio->uio_offset % bsize; - n = min((unsigned)(bsize - on), uio->uio_resid); + 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 = getblk(vp, bn, bsize, 0, 0, BLK_WRITE); + bp = buf_getblk(vp, bn, bsize, 0, 0, BLK_WRITE); else - error = bread(vp, bn, bsize, NOCRED, &bp); + 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) { - brelse(bp); + buf_brelse(bp); return (error); } - n = min(n, bsize - bp->b_resid); - - error = uiomove((char *)bp->b_data + on, n, uio); + n = min(n, bsize - buf_resid(bp)); - bp->b_flags |= B_AGE; + error = uiomove((char *)buf_dataptr(bp) + on, n, uio); + if (error) { + buf_brelse(bp); + return (error); + } + buf_markaged(bp); if (io_sync) - bwrite(bp); + error = buf_bwrite(bp); else { if ((n + on) == bsize) - bawrite(bp); + error = buf_bawrite(bp); else - bdwrite(bp); + error = buf_bdwrite(bp); } - } while (error == 0 && uio->uio_resid > 0 && n != 0); + } while (error == 0 && uio_resid(uio) > 0 && n != 0); return (error); default: panic("spec_write type"); } /* NOTREACHED */ + + return (0); } /* * Device ioctl operation. */ -/* ARGSUSED */ -spec_ioctl(ap) - struct vop_ioctl_args /* { - struct vnode *a_vp; - int a_command; - caddr_t a_data; - int a_fflag; - struct ucred *a_cred; - struct proc *a_p; - } */ *ap; +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, + 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, ap->a_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); - return ((*bdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, - ap->a_fflag, ap->a_p)); + 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; + break; default: panic("spec_ioctl"); /* NOTREACHED */ } + KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_IOCTL, 0) | DBG_FUNC_END, + dev, ap->a_command, ap->a_fflag, retval, 0); + + return (retval); } -/* ARGSUSED */ -spec_select(ap) - struct vop_select_args /* { - struct vnode *a_vp; - int a_which; - int a_fflags; - struct ucred *a_cred; - void * a_wql; - struct proc *a_p; - } */ *ap; +int +spec_select(struct vnop_select_args *ap) { - register dev_t dev; + proc_t p = vfs_context_proc(ap->a_context); + dev_t dev; switch (ap->a_vp->v_type) { @@ -524,344 +724,2220 @@ spec_select(ap) case VCHR: dev = ap->a_vp->v_rdev; - return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_wql, ap->a_p); + return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_wql, p); } } -/* - * Synch buffers associated with a block device - */ -/* ARGSUSED */ + +static int filt_specattach(struct knote *kn, struct kevent_internal_s *kev); + int -spec_fsync(ap) - struct vop_fsync_args /* { - struct vnode *a_vp; - struct ucred *a_cred; - int a_waitfor; - struct proc *a_p; - } */ *ap; -{ - register struct vnode *vp = ap->a_vp; - register struct buf *bp; - struct buf *nbp; - int s; +spec_kqfilter(vnode_t vp, struct knote *kn, struct kevent_internal_s *kev) +{ + dev_t dev; - if (vp->v_type == VCHR) - return (0); + assert(vnode_ischr(vp)); + + dev = vnode_specrdev(vp); + +#if NETWORKING /* - * Flush all dirty buffers associated with a block device. + * 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. */ -loop: - s = splbio(); - for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = nbp) { - nbp = bp->b_vnbufs.le_next; - if ((bp->b_flags & B_BUSY)) - continue; - if ((bp->b_flags & B_DELWRI) == 0) - panic("spec_fsync: not dirty"); - bremfree(bp); - bp->b_flags |= B_BUSY; - splx(s); - bawrite(bp); - goto loop; - } - if (ap->a_waitfor == MNT_WAIT) { - while (vp->v_numoutput) { - vp->v_flag |= VBWAIT; - tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "spec_fsync", 0); - } -#if DIAGNOSTIC - if (vp->v_dirtyblkhd.lh_first) { - vprint("spec_fsync: dirty", vp); - splx(s); - goto loop; - } + int32_t tmp_flags = kn->kn_flags; + int64_t tmp_data = kn->kn_data; + int res; + + res = bpfkqfilter(dev, kn); + if ((kn->kn_flags & EV_ERROR) == 0) { + return res; + } + kn->kn_flags = tmp_flags; + kn->kn_data = tmp_data; #endif + + if (major(dev) > nchrdev) { + knote_set_error(kn, ENXIO); + return 0; } - splx(s); - 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); } /* - * Just call the device strategy routine + * Synch buffers associated with a block device */ -spec_strategy(ap) - struct vop_strategy_args /* { - struct buf *a_bp; - } */ *ap; +int +spec_fsync_internal(vnode_t vp, int waitfor, __unused vfs_context_t context) { - (*bdevsw[major(ap->a_bp->b_dev)].d_strategy)(ap->a_bp); - return (0); -} + 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"); -/* - * This is a noop, simply returning what one has been given. - */ -spec_bmap(ap) - struct vop_bmap_args /* { - struct vnode *a_vp; - daddr_t a_bn; - struct vnode **a_vpp; - daddr_t *a_bnp; - int *a_runp; - } */ *ap; -{ - - if (ap->a_vpp != NULL) - *ap->a_vpp = ap->a_vp; - if (ap->a_bnp != NULL) - *ap->a_bnp = ap->a_bn * (PAGE_SIZE / ap->a_vp->v_specsize); - if (ap->a_runp != NULL) - *ap->a_runp = (MAXPHYSIO / PAGE_SIZE) - 1; return (0); } -/* - * This is a noop, simply returning what one has been given. - */ -spec_cmap(ap) - struct vop_cmap_args /* { - struct vnode *a_vp; - off_t a_offset; - size_t a_size; - daddr_t *a_bpn; - size_t *a_run; - void *a_poff; - } */ *ap; +int +spec_fsync(struct vnop_fsync_args *ap) { - return (EOPNOTSUPP); + return spec_fsync_internal(ap->a_vp, ap->a_waitfor, ap->a_context); } /* - * Device close routine + * Just call the device strategy routine */ -/* ARGSUSED */ -spec_close(ap) - struct vop_close_args /* { - struct vnode *a_vp; - int a_fflag; - struct ucred *a_cred; - struct proc *a_p; - } */ *ap; -{ - register struct vnode *vp = ap->a_vp; - dev_t dev = vp->v_rdev; - int (*devclose) __P((dev_t, int, int, struct proc *)); - int mode, error; +void throttle_init(void); - 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 && ap->a_p && - vp == ap->a_p->p_session->s_ttyvp) { - ap->a_p->p_session->s_ttyvp = NULL; - vrele(vp); - } - /* - * If the vnode is locked, then we are in the midst - * of forcably closing the device, otherwise we only - * close on last reference. - */ - if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) - return (0); - devclose = cdevsw[major(dev)].d_close; - mode = S_IFCHR; - break; +#if 0 +#define DEBUG_ALLOC_THROTTLE_INFO(format, debug_info, args...) \ + do { \ + if ((debug_info)->alloc) \ + printf("%s: "format, __FUNCTION__, ## args); \ + } while(0) - 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. - */ - vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_p); - error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0); - VOP_UNLOCK(vp, 0, ap->a_p); - if (error) - return (error); - /* - * We do not want to really close the device if it - * is still in use unless we are trying to close it - * forcibly. Since every use (buffer, vnode, swap, cmap) - * 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 && (vp->v_flag & VXLOCK) == 0) - return (0); -#else /* DEVFS_IMPLEMENTS_LOCKING */ - /* - * We do not want to really close the device if it - * is still in use unless we are trying to close it - * forcibly. Since every use (buffer, vnode, swap, cmap) - * 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 && (vp->v_flag & VXLOCK) == 0) - return (0); +#else +#define DEBUG_ALLOC_THROTTLE_INFO(format, debug_info, args...) +#endif - /* - * 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. - */ - error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0); - if (error) - return (error); -#endif /* DEVFS_IMPLEMENTS_LOCKING */ - devclose = bdevsw[major(dev)].d_close; - mode = S_IFBLK; - break; - default: - panic("spec_close: not special"); - } +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_lock_grp; +static lck_attr_t *throttle_lock_attr; +static lck_grp_attr_t *throttle_lock_grp_attr; - return ((*devclose)(dev, ap->a_fflag, mode, ap->a_p)); -} /* - * Print out the contents of a special device vnode. + * throttled I/O helper function + * convert the index of the lowest set bit to a device index */ -spec_print(ap) - struct vop_print_args /* { - struct vnode *a_vp; - } */ *ap; +int +num_trailing_0(uint64_t n) { - - printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev), - minor(ap->a_vp->v_rdev)); + /* + * 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; } + /* - * Return POSIX pathconf information applicable to special devices. + * 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. */ -spec_pathconf(ap) - struct vop_pathconf_args /* { - struct vnode *a_vp; - int a_name; - int *a_retval; - } */ *ap; +static int +throttle_info_rel(struct _throttle_io_info_t *info) { + SInt32 oldValue = OSDecrementAtomic(&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 ); + + /* 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_lock_grp); + FREE(info, M_TEMP); } - /* NOTREACHED */ + return oldValue; } -int -spec_devblocksize(ap) - struct vop_devblocksize_args /* { - struct vnode *a_vp; - int *a_retval; - } */ *ap; -{ - *ap->a_retval = (ap->a_vp->v_specsize); - return (0); -} /* - * Special device failed operation + * Just take a reference on the throttle info structure. + * + * This routine always returns the old value. */ -spec_ebadf() +static SInt32 +throttle_info_ref(struct _throttle_io_info_t *info) { + SInt32 oldValue = OSIncrementAtomic(&info->throttle_refcnt); - return (EBADF); + 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; } /* - * Special device bad 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 */ -spec_badop() -{ +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] || 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++) { - panic("spec_badop called"); - /* NOTREACHED */ -} + if (TAILQ_EMPTY(&info->throttle_uthlist[level])) + continue; -/* Blktooff derives file offset from logical block number */ -int -spec_blktooff(ap) - struct vop_blktooff_args /* { - struct vnode *a_vp; - daddr_t a_lblkno; - off_t *a_offset; - } */ *ap; -{ - register struct vnode *vp = ap->a_vp; + target = info->throttle_start_IO_period_timestamp[level]; - switch (vp->v_type) { - case VCHR: - *ap->a_offset = (off_t)-1; /* failure */ - return (EOPNOTSUPP); + msecs = info->throttle_io_periods[level]; + period.tv_sec = msecs / 1000; + period.tv_usec = (msecs % 1000) * 1000; - case VBLK: - printf("spec_blktooff: not implemented for VBLK\n"); - *ap->a_offset = (off_t)-1; /* failure */ - return (EOPNOTSUPP); + 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; + } - default: - panic("spec_blktooff type"); - } - /* NOTREACHED */ -} + 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; -/* Offtoblk derives logical block number from file offset */ -int -spec_offtoblk(ap) - struct vop_offtoblk_args /* { - struct vnode *a_vp; - off_t a_offset; - daddr_t *a_lblkno; - } */ *ap; + 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(int flag) +{ + if (flag == THROTTLE_IO_ENABLE) + lowpri_throttle_enabled = 1; + + if (flag == THROTTLE_IO_DISABLE) + lowpri_throttle_enabled = 0; +} + +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 == FALSE) + 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 == TRUE) + 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 == FALSE) + 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 == TRUE) { + + 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); +} + +/* + * 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)) { + 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, (int)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(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) { - register struct vnode *vp = ap->a_vp; + struct vnode *vp = ap->a_vp; switch (vp->v_type) { case VCHR: - *ap->a_lblkno = (daddr_t)-1; /* failure */ - return (EOPNOTSUPP); + *ap->a_lblkno = (daddr64_t)-1; /* failure */ + return (ENOTSUP); case VBLK: printf("spec_offtoblk: not implemented for VBLK\n"); - *ap->a_lblkno = (daddr_t)-1; /* failure */ - return (EOPNOTSUPP); + *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_specevent(struct knote *kn, long hint); +static int filt_spectouch(struct knote *kn, struct kevent_internal_s *kev); +static int filt_specprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev); +static unsigned 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, kn->kn_hookid); + 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_data 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); + /* + * 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_data 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. + */ + kn->kn_hook_data = 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 void filt_spec_common(struct knote *kn, int selres) +{ + if (kn->kn_vnode_use_ofst) { + 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; + } +} + +static int +filt_specattach(struct knote *kn, __unused struct kevent_internal_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_data = 0; + kn->kn_hookid = vnode_vid(vp); + + 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_data 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_data) { + waitq_unlink_by_prepost_id(kn->kn_hook_data, &(knote_get_kq(kn)->kq_wqs)); + kn->kn_hook_data = 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_internal_s *kev) +{ + kn->kn_sdata = kev->data; + kn->kn_sfflags = kev->fflags; + if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0) + kn->kn_udata = kev->udata; + + if (kev->flags & EV_ENABLE) { + return spec_knote_select_and_link(kn); + } + + return 0; +} + +static int +filt_specprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev) +{ +#pragma unused(data) + 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; + + /* FIXME JMM - locking against touches? */ + + error = vnode_getwithvid(vp, kn->kn_hookid); + if (error != 0) { + kn->kn_flags |= (EV_EOF | EV_ONESHOT); + *kev = kn->kn_kevent; + return 1; + } + + selres = spec_knote_select_and_link(kn); + filt_spec_common(kn, selres); + + vnode_put(vp); + + res = ((kn->kn_sfflags & NOTE_LOWAT) != 0) ? + (kn->kn_data >= kn->kn_sdata) : kn->kn_data; + + if (res) { + *kev = kn->kn_kevent; + if (kn->kn_flags & EV_CLEAR) { + kn->kn_fflags = 0; + kn->kn_data = 0; + } + } + + return res; +} + +static unsigned +filt_specpeek(struct knote *kn) +{ + int selres = 0; + + selres = spec_knote_select_and_link(kn); + filt_spec_common(kn, selres); + + return kn->kn_data; +} +