/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright 2011 Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2012, 2016 by Delphix. All rights reserved. * Copyright (c) 2012, Joyent, Inc. All rights reserved. */ #ifndef _SYS_ZFS_CONTEXT_H #define _SYS_ZFS_CONTEXT_H #ifdef __KERNEL__ #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 #include #else /* _KERNEL */ #define _SYS_MUTEX_H #define _SYS_RWLOCK_H #define _SYS_CONDVAR_H #define _SYS_SYSTM_H #define _SYS_T_LOCK_H #define _SYS_VNODE_H #define _SYS_VFS_H #define _SYS_SUNDDI_H #define _SYS_CALLB_H #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 #include /* * Stack */ #define noinline __attribute__((noinline)) #define likely(x) __builtin_expect((x), 1) /* * Debugging */ /* * Note that we are not using the debugging levels. */ #define CE_CONT 0 /* continuation */ #define CE_NOTE 1 /* notice */ #define CE_WARN 2 /* warning */ #define CE_PANIC 3 /* panic */ #define CE_IGNORE 4 /* print nothing */ /* * ZFS debugging */ extern void dprintf_setup(int *argc, char **argv); extern void cmn_err(int, const char *, ...); extern void vcmn_err(int, const char *, va_list); extern void panic(const char *, ...) __NORETURN; extern void vpanic(const char *, va_list) __NORETURN; #define fm_panic panic extern int aok; /* * DTrace SDT probes have different signatures in userland than they do in * the kernel. If they're being used in kernel code, re-define them out of * existence for their counterparts in libzpool. * * Here's an example of how to use the set-error probes in userland: * zfs$target:::set-error /arg0 == EBUSY/ {stack();} * * Here's an example of how to use DTRACE_PROBE probes in userland: * If there is a probe declared as follows: * DTRACE_PROBE2(zfs__probe_name, uint64_t, blkid, dnode_t *, dn); * Then you can use it as follows: * zfs$target:::probe2 /copyinstr(arg0) == "zfs__probe_name"/ * {printf("%u %p\n", arg1, arg2);} */ #ifdef DTRACE_PROBE #undef DTRACE_PROBE #endif /* DTRACE_PROBE */ #define DTRACE_PROBE(a) \ ZFS_PROBE0(#a) #ifdef DTRACE_PROBE1 #undef DTRACE_PROBE1 #endif /* DTRACE_PROBE1 */ #define DTRACE_PROBE1(a, b, c) \ ZFS_PROBE1(#a, (unsigned long)c) #ifdef DTRACE_PROBE2 #undef DTRACE_PROBE2 #endif /* DTRACE_PROBE2 */ #define DTRACE_PROBE2(a, b, c, d, e) \ ZFS_PROBE2(#a, (unsigned long)c, (unsigned long)e) #ifdef DTRACE_PROBE3 #undef DTRACE_PROBE3 #endif /* DTRACE_PROBE3 */ #define DTRACE_PROBE3(a, b, c, d, e, f, g) \ ZFS_PROBE3(#a, (unsigned long)c, (unsigned long)e, (unsigned long)g) #ifdef DTRACE_PROBE4 #undef DTRACE_PROBE4 #endif /* DTRACE_PROBE4 */ #define DTRACE_PROBE4(a, b, c, d, e, f, g, h, i) \ ZFS_PROBE4(#a, (unsigned long)c, (unsigned long)e, (unsigned long)g, \ (unsigned long)i) /* * Threads. */ typedef pthread_t kthread_t; #define TS_RUN 0x00000002 #define TS_JOINABLE 0x00000004 #define curthread ((void *)(uintptr_t)pthread_self()) #define kpreempt(x) yield() #define getcomm() "unknown" #define thread_create(stk, stksize, func, arg, len, pp, state, pri) \ zk_thread_create(func, arg, stksize, state) #define thread_exit() pthread_exit(NULL) #define thread_join(t) pthread_join((pthread_t)(t), NULL) #define newproc(f, a, cid, pri, ctp, pid) (ENOSYS) /* in libzpool, p0 exists only to have its address taken */ typedef struct proc { uintptr_t this_is_never_used_dont_dereference_it; } proc_t; extern struct proc p0; #define curproc (&p0) #define PS_NONE -1 extern kthread_t *zk_thread_create(void (*func)(void *), void *arg, size_t stksize, int state); #define issig(why) (FALSE) #define ISSIG(thr, why) (FALSE) #define kpreempt_disable() ((void)0) #define kpreempt_enable() ((void)0) /* * Mutexes */ typedef struct kmutex { pthread_mutex_t m_lock; pthread_t m_owner; } kmutex_t; #define MUTEX_DEFAULT 0 #define MUTEX_NOLOCKDEP MUTEX_DEFAULT #define MUTEX_HELD(mp) pthread_equal((mp)->m_owner, pthread_self()) #define MUTEX_NOT_HELD(mp) !MUTEX_HELD(mp) extern void mutex_init(kmutex_t *mp, char *name, int type, void *cookie); extern void mutex_destroy(kmutex_t *mp); extern void mutex_enter(kmutex_t *mp); extern void mutex_exit(kmutex_t *mp); extern int mutex_tryenter(kmutex_t *mp); /* * RW locks */ typedef struct krwlock { pthread_rwlock_t rw_lock; pthread_t rw_owner; uint_t rw_readers; } krwlock_t; typedef int krw_t; #define RW_READER 0 #define RW_WRITER 1 #define RW_DEFAULT RW_READER #define RW_NOLOCKDEP RW_READER #define RW_READ_HELD(rw) ((rw)->rw_readers > 0) #define RW_WRITE_HELD(rw) pthread_equal((rw)->rw_owner, pthread_self()) #define RW_LOCK_HELD(rw) (RW_READ_HELD(rw) || RW_WRITE_HELD(rw)) extern void rw_init(krwlock_t *rwlp, char *name, int type, void *arg); extern void rw_destroy(krwlock_t *rwlp); extern void rw_enter(krwlock_t *rwlp, krw_t rw); extern int rw_tryenter(krwlock_t *rwlp, krw_t rw); extern int rw_tryupgrade(krwlock_t *rwlp); extern void rw_exit(krwlock_t *rwlp); #define rw_downgrade(rwlp) do { } while (0) /* * Credentials */ extern uid_t crgetuid(cred_t *cr); extern uid_t crgetruid(cred_t *cr); extern gid_t crgetgid(cred_t *cr); extern int crgetngroups(cred_t *cr); extern gid_t *crgetgroups(cred_t *cr); /* * Condition variables */ typedef pthread_cond_t kcondvar_t; #define CV_DEFAULT 0 #define CALLOUT_FLAG_ABSOLUTE 0x2 extern void cv_init(kcondvar_t *cv, char *name, int type, void *arg); extern void cv_destroy(kcondvar_t *cv); extern void cv_wait(kcondvar_t *cv, kmutex_t *mp); extern clock_t cv_timedwait(kcondvar_t *cv, kmutex_t *mp, clock_t abstime); extern clock_t cv_timedwait_hires(kcondvar_t *cvp, kmutex_t *mp, hrtime_t tim, hrtime_t res, int flag); extern void cv_signal(kcondvar_t *cv); extern void cv_broadcast(kcondvar_t *cv); #define cv_timedwait_io(cv, mp, at) cv_timedwait(cv, mp, at) #define cv_timedwait_sig(cv, mp, at) cv_timedwait(cv, mp, at) #define cv_wait_sig(cv, mp) cv_wait(cv, mp) #define cv_wait_io(cv, mp) cv_wait(cv, mp) #define cv_timedwait_sig_hires(cv, mp, t, r, f) \ cv_timedwait_hires(cv, mp, t, r, f) /* * Thread-specific data */ #define tsd_get(k) pthread_getspecific(k) #define tsd_set(k, v) pthread_setspecific(k, v) #define tsd_create(kp, d) pthread_key_create(kp, d) #define tsd_destroy(kp) /* nothing */ /* * Thread-specific data */ #define tsd_get(k) pthread_getspecific(k) #define tsd_set(k, v) pthread_setspecific(k, v) #define tsd_create(kp, d) pthread_key_create(kp, d) #define tsd_destroy(kp) /* nothing */ /* * kstat creation, installation and deletion */ extern kstat_t *kstat_create(const char *, int, const char *, const char *, uchar_t, ulong_t, uchar_t); extern void kstat_named_init(kstat_named_t *, const char *, uchar_t); extern void kstat_install(kstat_t *); extern void kstat_delete(kstat_t *); extern void kstat_waitq_enter(kstat_io_t *); extern void kstat_waitq_exit(kstat_io_t *); extern void kstat_runq_enter(kstat_io_t *); extern void kstat_runq_exit(kstat_io_t *); extern void kstat_waitq_to_runq(kstat_io_t *); extern void kstat_runq_back_to_waitq(kstat_io_t *); extern void kstat_set_raw_ops(kstat_t *ksp, int (*headers)(char *buf, size_t size), int (*data)(char *buf, size_t size, void *data), void *(*addr)(kstat_t *ksp, loff_t index)); /* * Kernel memory */ #define KM_SLEEP UMEM_NOFAIL #define KM_PUSHPAGE KM_SLEEP #define KM_NOSLEEP UMEM_DEFAULT #define KM_NORMALPRI 0 /* not needed with UMEM_DEFAULT */ #define KMC_NODEBUG UMC_NODEBUG #define KMC_KMEM 0x0 #define KMC_VMEM 0x0 #define kmem_alloc(_s, _f) umem_alloc(_s, _f) #define kmem_zalloc(_s, _f) umem_zalloc(_s, _f) #define kmem_free(_b, _s) umem_free(_b, _s) #define vmem_alloc(_s, _f) kmem_alloc(_s, _f) #define vmem_zalloc(_s, _f) kmem_zalloc(_s, _f) #define vmem_free(_b, _s) kmem_free(_b, _s) #define kmem_cache_create(_a, _b, _c, _d, _e, _f, _g, _h, _i) \ umem_cache_create(_a, _b, _c, _d, _e, _f, _g, _h, _i) #define kmem_cache_destroy(_c) umem_cache_destroy(_c) #define kmem_cache_alloc(_c, _f) umem_cache_alloc(_c, _f) #define kmem_cache_free(_c, _b) umem_cache_free(_c, _b) #define kmem_debugging() 0 #define kmem_cache_reap_now(_c) umem_cache_reap_now(_c); #define kmem_cache_set_move(_c, _cb) /* nothing */ #define vmem_qcache_reap(_v) /* nothing */ #define POINTER_INVALIDATE(_pp) /* nothing */ #define POINTER_IS_VALID(_p) 0 extern vmem_t *zio_arena; typedef umem_cache_t kmem_cache_t; typedef enum kmem_cbrc { KMEM_CBRC_YES, KMEM_CBRC_NO, KMEM_CBRC_LATER, KMEM_CBRC_DONT_NEED, KMEM_CBRC_DONT_KNOW } kmem_cbrc_t; /* * Task queues */ #define TASKQ_NAMELEN 31 typedef uintptr_t taskqid_t; typedef void (task_func_t)(void *); typedef struct taskq_ent { struct taskq_ent *tqent_next; struct taskq_ent *tqent_prev; task_func_t *tqent_func; void *tqent_arg; uintptr_t tqent_flags; } taskq_ent_t; typedef struct taskq { char tq_name[TASKQ_NAMELEN + 1]; kmutex_t tq_lock; krwlock_t tq_threadlock; kcondvar_t tq_dispatch_cv; kcondvar_t tq_wait_cv; kthread_t **tq_threadlist; int tq_flags; int tq_active; int tq_nthreads; int tq_nalloc; int tq_minalloc; int tq_maxalloc; kcondvar_t tq_maxalloc_cv; int tq_maxalloc_wait; taskq_ent_t *tq_freelist; taskq_ent_t tq_task; } taskq_t; #define TQENT_FLAG_PREALLOC 0x1 /* taskq_dispatch_ent used */ #define TASKQ_PREPOPULATE 0x0001 #define TASKQ_CPR_SAFE 0x0002 /* Use CPR safe protocol */ #define TASKQ_DYNAMIC 0x0004 /* Use dynamic thread scheduling */ #define TASKQ_THREADS_CPU_PCT 0x0008 /* Scale # threads by # cpus */ #define TASKQ_DC_BATCH 0x0010 /* Mark threads as batch */ #define TQ_SLEEP KM_SLEEP /* Can block for memory */ #define TQ_NOSLEEP KM_NOSLEEP /* cannot block for memory; may fail */ #define TQ_NOQUEUE 0x02 /* Do not enqueue if can't dispatch */ #define TQ_FRONT 0x08 /* Queue in front */ #define TASKQID_INVALID ((taskqid_t)0) extern taskq_t *system_taskq; extern taskq_t *system_delay_taskq; extern taskq_t *taskq_create(const char *, int, pri_t, int, int, uint_t); #define taskq_create_proc(a, b, c, d, e, p, f) \ (taskq_create(a, b, c, d, e, f)) #define taskq_create_sysdc(a, b, d, e, p, dc, f) \ (taskq_create(a, b, maxclsyspri, d, e, f)) extern taskqid_t taskq_dispatch(taskq_t *, task_func_t, void *, uint_t); extern taskqid_t taskq_dispatch_delay(taskq_t *, task_func_t, void *, uint_t, clock_t); extern void taskq_dispatch_ent(taskq_t *, task_func_t, void *, uint_t, taskq_ent_t *); extern int taskq_empty_ent(taskq_ent_t *); extern void taskq_init_ent(taskq_ent_t *); extern void taskq_destroy(taskq_t *); extern void taskq_wait(taskq_t *); extern void taskq_wait_id(taskq_t *, taskqid_t); extern void taskq_wait_outstanding(taskq_t *, taskqid_t); extern int taskq_member(taskq_t *, kthread_t *); extern int taskq_cancel_id(taskq_t *, taskqid_t); extern void system_taskq_init(void); extern void system_taskq_fini(void); #define XVA_MAPSIZE 3 #define XVA_MAGIC 0x78766174 /* * vnodes */ typedef struct vnode { uint64_t v_size; int v_fd; char *v_path; int v_dump_fd; } vnode_t; extern char *vn_dumpdir; #define AV_SCANSTAMP_SZ 32 /* length of anti-virus scanstamp */ typedef struct xoptattr { timestruc_t xoa_createtime; /* Create time of file */ uint8_t xoa_archive; uint8_t xoa_system; uint8_t xoa_readonly; uint8_t xoa_hidden; uint8_t xoa_nounlink; uint8_t xoa_immutable; uint8_t xoa_appendonly; uint8_t xoa_nodump; uint8_t xoa_settable; uint8_t xoa_opaque; uint8_t xoa_av_quarantined; uint8_t xoa_av_modified; uint8_t xoa_av_scanstamp[AV_SCANSTAMP_SZ]; uint8_t xoa_reparse; uint8_t xoa_offline; uint8_t xoa_sparse; } xoptattr_t; typedef struct vattr { uint_t va_mask; /* bit-mask of attributes */ u_offset_t va_size; /* file size in bytes */ } vattr_t; typedef struct xvattr { vattr_t xva_vattr; /* Embedded vattr structure */ uint32_t xva_magic; /* Magic Number */ uint32_t xva_mapsize; /* Size of attr bitmap (32-bit words) */ uint32_t *xva_rtnattrmapp; /* Ptr to xva_rtnattrmap[] */ uint32_t xva_reqattrmap[XVA_MAPSIZE]; /* Requested attrs */ uint32_t xva_rtnattrmap[XVA_MAPSIZE]; /* Returned attrs */ xoptattr_t xva_xoptattrs; /* Optional attributes */ } xvattr_t; typedef struct vsecattr { uint_t vsa_mask; /* See below */ int vsa_aclcnt; /* ACL entry count */ void *vsa_aclentp; /* pointer to ACL entries */ int vsa_dfaclcnt; /* default ACL entry count */ void *vsa_dfaclentp; /* pointer to default ACL entries */ size_t vsa_aclentsz; /* ACE size in bytes of vsa_aclentp */ } vsecattr_t; #define AT_TYPE 0x00001 #define AT_MODE 0x00002 #define AT_UID 0x00004 #define AT_GID 0x00008 #define AT_FSID 0x00010 #define AT_NODEID 0x00020 #define AT_NLINK 0x00040 #define AT_SIZE 0x00080 #define AT_ATIME 0x00100 #define AT_MTIME 0x00200 #define AT_CTIME 0x00400 #define AT_RDEV 0x00800 #define AT_BLKSIZE 0x01000 #define AT_NBLOCKS 0x02000 #define AT_SEQ 0x08000 #define AT_XVATTR 0x10000 #define CRCREAT 0 extern int fop_getattr(vnode_t *vp, vattr_t *vap); #define VOP_CLOSE(vp, f, c, o, cr, ct) vn_close(vp) #define VOP_PUTPAGE(vp, of, sz, fl, cr, ct) 0 #define VOP_GETATTR(vp, vap, fl, cr, ct) fop_getattr((vp), (vap)); #define VOP_FSYNC(vp, f, cr, ct) fsync((vp)->v_fd) #define VN_RELE(vp) vn_close(vp) extern int vn_open(char *path, int x1, int oflags, int mode, vnode_t **vpp, int x2, int x3); extern int vn_openat(char *path, int x1, int oflags, int mode, vnode_t **vpp, int x2, int x3, vnode_t *vp, int fd); extern int vn_rdwr(int uio, vnode_t *vp, void *addr, ssize_t len, offset_t offset, int x1, int x2, rlim64_t x3, void *x4, ssize_t *residp); extern void vn_close(vnode_t *vp); #define vn_remove(path, x1, x2) remove(path) #define vn_rename(from, to, seg) rename((from), (to)) #define vn_is_readonly(vp) B_FALSE extern vnode_t *rootdir; #include /* for FREAD, FWRITE, etc */ /* * Random stuff */ #define ddi_get_lbolt() (gethrtime() >> 23) #define ddi_get_lbolt64() (gethrtime() >> 23) #define hz 119 /* frequency when using gethrtime() >> 23 for lbolt */ #define ddi_time_before(a, b) (a < b) #define ddi_time_after(a, b) ddi_time_before(b, a) #define ddi_time_before_eq(a, b) (!ddi_time_after(a, b)) #define ddi_time_after_eq(a, b) ddi_time_before_eq(b, a) #define ddi_time_before64(a, b) (a < b) #define ddi_time_after64(a, b) ddi_time_before64(b, a) #define ddi_time_before_eq64(a, b) (!ddi_time_after64(a, b)) #define ddi_time_after_eq64(a, b) ddi_time_before_eq64(b, a) extern void delay(clock_t ticks); #define SEC_TO_TICK(sec) ((sec) * hz) #define MSEC_TO_TICK(msec) ((msec) / (MILLISEC / hz)) #define USEC_TO_TICK(usec) ((usec) / (MICROSEC / hz)) #define NSEC_TO_TICK(usec) ((usec) / (NANOSEC / hz)) #define gethrestime_sec() time(NULL) #define gethrestime(t) \ do {\ (t)->tv_sec = gethrestime_sec();\ (t)->tv_nsec = 0;\ } while (0); #define max_ncpus 64 #define boot_ncpus (sysconf(_SC_NPROCESSORS_ONLN)) /* * Process priorities as defined by setpriority(2) and getpriority(2). */ #define minclsyspri 19 #define maxclsyspri -20 #define defclsyspri 0 #define CPU_SEQID ((uintptr_t)pthread_self() & (max_ncpus - 1)) #define kcred NULL #define CRED() NULL #define ptob(x) ((x) * PAGESIZE) #define NN_DIVISOR_1000 (1U << 0) #define NN_NUMBUF_SZ (6) extern uint64_t physmem; extern char *random_path; extern char *urandom_path; extern int highbit64(uint64_t i); extern int lowbit64(uint64_t i); extern int random_get_bytes(uint8_t *ptr, size_t len); extern int random_get_pseudo_bytes(uint8_t *ptr, size_t len); extern void kernel_init(int); extern void kernel_fini(void); extern void random_init(void); extern void random_fini(void); struct spa; extern void nicenum(uint64_t num, char *buf, size_t); extern void show_pool_stats(struct spa *); extern int set_global_var(char *arg); typedef struct callb_cpr { kmutex_t *cc_lockp; } callb_cpr_t; #define CALLB_CPR_INIT(cp, lockp, func, name) { \ (cp)->cc_lockp = lockp; \ } #define CALLB_CPR_SAFE_BEGIN(cp) { \ ASSERT(MUTEX_HELD((cp)->cc_lockp)); \ } #define CALLB_CPR_SAFE_END(cp, lockp) { \ ASSERT(MUTEX_HELD((cp)->cc_lockp)); \ } #define CALLB_CPR_EXIT(cp) { \ ASSERT(MUTEX_HELD((cp)->cc_lockp)); \ mutex_exit((cp)->cc_lockp); \ } #define zone_dataset_visible(x, y) (1) #define INGLOBALZONE(z) (1) extern char *kmem_vasprintf(const char *fmt, va_list adx); extern char *kmem_asprintf(const char *fmt, ...); #define strfree(str) kmem_free((str), strlen(str) + 1) /* * Hostname information */ extern char hw_serial[]; /* for userland-emulated hostid access */ extern int ddi_strtoul(const char *str, char **nptr, int base, unsigned long *result); extern int ddi_strtoull(const char *str, char **nptr, int base, u_longlong_t *result); typedef struct utsname utsname_t; extern utsname_t *utsname(void); /* ZFS Boot Related stuff. */ struct _buf { intptr_t _fd; }; struct bootstat { uint64_t st_size; }; typedef struct ace_object { uid_t a_who; uint32_t a_access_mask; uint16_t a_flags; uint16_t a_type; uint8_t a_obj_type[16]; uint8_t a_inherit_obj_type[16]; } ace_object_t; #define ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE 0x05 #define ACE_ACCESS_DENIED_OBJECT_ACE_TYPE 0x06 #define ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE 0x07 #define ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE 0x08 extern struct _buf *kobj_open_file(char *name); extern int kobj_read_file(struct _buf *file, char *buf, unsigned size, unsigned off); extern void kobj_close_file(struct _buf *file); extern int kobj_get_filesize(struct _buf *file, uint64_t *size); extern int zfs_secpolicy_snapshot_perms(const char *name, cred_t *cr); extern int zfs_secpolicy_rename_perms(const char *from, const char *to, cred_t *cr); extern int zfs_secpolicy_destroy_perms(const char *name, cred_t *cr); extern int secpolicy_zfs(const cred_t *cr); extern zoneid_t getzoneid(void); /* SID stuff */ typedef struct ksiddomain { uint_t kd_ref; uint_t kd_len; char *kd_name; } ksiddomain_t; ksiddomain_t *ksid_lookupdomain(const char *); void ksiddomain_rele(ksiddomain_t *); #define DDI_SLEEP KM_SLEEP #define ddi_log_sysevent(_a, _b, _c, _d, _e, _f, _g) \ sysevent_post_event(_c, _d, _b, "libzpool", _e, _f) #define zfs_sleep_until(wakeup) \ do { \ hrtime_t delta = wakeup - gethrtime(); \ struct timespec ts; \ ts.tv_sec = delta / NANOSEC; \ ts.tv_nsec = delta % NANOSEC; \ (void) nanosleep(&ts, NULL); \ } while (0) typedef int fstrans_cookie_t; extern fstrans_cookie_t spl_fstrans_mark(void); extern void spl_fstrans_unmark(fstrans_cookie_t); extern int __spl_pf_fstrans_check(void); #endif /* _KERNEL */ #endif /* _SYS_ZFS_CONTEXT_H */