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vfs_wapbl.c revision 1.100
      1 /*	$NetBSD: vfs_wapbl.c,v 1.100 2017/10/27 12:25:15 joerg Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2003, 2008, 2009 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Wasabi Systems, Inc.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * This implements file system independent write ahead filesystem logging.
     34  */
     35 
     36 #define WAPBL_INTERNAL
     37 
     38 #include <sys/cdefs.h>
     39 __KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.100 2017/10/27 12:25:15 joerg Exp $");
     40 
     41 #include <sys/param.h>
     42 #include <sys/bitops.h>
     43 #include <sys/time.h>
     44 #include <sys/wapbl.h>
     45 #include <sys/wapbl_replay.h>
     46 
     47 #ifdef _KERNEL
     48 
     49 #include <sys/atomic.h>
     50 #include <sys/conf.h>
     51 #include <sys/evcnt.h>
     52 #include <sys/file.h>
     53 #include <sys/kauth.h>
     54 #include <sys/kernel.h>
     55 #include <sys/module.h>
     56 #include <sys/mount.h>
     57 #include <sys/mutex.h>
     58 #include <sys/namei.h>
     59 #include <sys/proc.h>
     60 #include <sys/resourcevar.h>
     61 #include <sys/sysctl.h>
     62 #include <sys/uio.h>
     63 #include <sys/vnode.h>
     64 
     65 #include <miscfs/specfs/specdev.h>
     66 
     67 #define	wapbl_alloc(s) kmem_alloc((s), KM_SLEEP)
     68 #define	wapbl_free(a, s) kmem_free((a), (s))
     69 #define	wapbl_calloc(n, s) kmem_zalloc((n)*(s), KM_SLEEP)
     70 
     71 static struct sysctllog *wapbl_sysctl;
     72 static int wapbl_flush_disk_cache = 1;
     73 static int wapbl_verbose_commit = 0;
     74 static int wapbl_allow_dpofua = 0; 	/* switched off by default for now */
     75 static int wapbl_journal_iobufs = 4;
     76 
     77 static inline size_t wapbl_space_free(size_t, off_t, off_t);
     78 
     79 #else /* !_KERNEL */
     80 
     81 #include <assert.h>
     82 #include <errno.h>
     83 #include <stdbool.h>
     84 #include <stdio.h>
     85 #include <stdlib.h>
     86 #include <string.h>
     87 
     88 #define	KDASSERT(x) assert(x)
     89 #define	KASSERT(x) assert(x)
     90 #define	wapbl_alloc(s) malloc(s)
     91 #define	wapbl_free(a, s) free(a)
     92 #define	wapbl_calloc(n, s) calloc((n), (s))
     93 
     94 #endif /* !_KERNEL */
     95 
     96 /*
     97  * INTERNAL DATA STRUCTURES
     98  */
     99 
    100 /*
    101  * This structure holds per-mount log information.
    102  *
    103  * Legend:	a = atomic access only
    104  *		r = read-only after init
    105  *		l = rwlock held
    106  *		m = mutex held
    107  *		lm = rwlock held writing or mutex held
    108  *		u = unlocked access ok
    109  *		b = bufcache_lock held
    110  */
    111 LIST_HEAD(wapbl_ino_head, wapbl_ino);
    112 struct wapbl {
    113 	struct vnode *wl_logvp;	/* r:	log here */
    114 	struct vnode *wl_devvp;	/* r:	log on this device */
    115 	struct mount *wl_mount;	/* r:	mountpoint wl is associated with */
    116 	daddr_t wl_logpbn;	/* r:	Physical block number of start of log */
    117 	int wl_log_dev_bshift;	/* r:	logarithm of device block size of log
    118 					device */
    119 	int wl_fs_dev_bshift;	/* r:	logarithm of device block size of
    120 					filesystem device */
    121 
    122 	unsigned wl_lock_count;	/* m:	Count of transactions in progress */
    123 
    124 	size_t wl_circ_size; 	/* r:	Number of bytes in buffer of log */
    125 	size_t wl_circ_off;	/* r:	Number of bytes reserved at start */
    126 
    127 	size_t wl_bufcount_max;	/* r:	Number of buffers reserved for log */
    128 	size_t wl_bufbytes_max;	/* r:	Number of buf bytes reserved for log */
    129 
    130 	off_t wl_head;		/* l:	Byte offset of log head */
    131 	off_t wl_tail;		/* l:	Byte offset of log tail */
    132 	/*
    133 	 * WAPBL log layout, stored on wl_devvp at wl_logpbn:
    134 	 *
    135 	 *  ___________________ wl_circ_size __________________
    136 	 * /                                                   \
    137 	 * +---------+---------+-------+--------------+--------+
    138 	 * [ commit0 | commit1 | CCWCW | EEEEEEEEEEEE | CCCWCW ]
    139 	 * +---------+---------+-------+--------------+--------+
    140 	 *       wl_circ_off --^       ^-- wl_head    ^-- wl_tail
    141 	 *
    142 	 * commit0 and commit1 are commit headers.  A commit header has
    143 	 * a generation number, indicating which of the two headers is
    144 	 * more recent, and an assignment of head and tail pointers.
    145 	 * The rest is a circular queue of log records, starting at
    146 	 * the byte offset wl_circ_off.
    147 	 *
    148 	 * E marks empty space for records.
    149 	 * W marks records for block writes issued but waiting.
    150 	 * C marks completed records.
    151 	 *
    152 	 * wapbl_flush writes new records to empty `E' spaces after
    153 	 * wl_head from the current transaction in memory.
    154 	 *
    155 	 * wapbl_truncate advances wl_tail past any completed `C'
    156 	 * records, freeing them up for use.
    157 	 *
    158 	 * head == tail == 0 means log is empty.
    159 	 * head == tail != 0 means log is full.
    160 	 *
    161 	 * See assertions in wapbl_advance() for other boundary
    162 	 * conditions.
    163 	 *
    164 	 * Only wapbl_flush moves the head, except when wapbl_truncate
    165 	 * sets it to 0 to indicate that the log is empty.
    166 	 *
    167 	 * Only wapbl_truncate moves the tail, except when wapbl_flush
    168 	 * sets it to wl_circ_off to indicate that the log is full.
    169 	 */
    170 
    171 	struct wapbl_wc_header *wl_wc_header;	/* l	*/
    172 	void *wl_wc_scratch;	/* l:	scratch space (XXX: por que?!?) */
    173 
    174 	kmutex_t wl_mtx;	/* u:	short-term lock */
    175 	krwlock_t wl_rwlock;	/* u:	File system transaction lock */
    176 
    177 	/*
    178 	 * Must be held while accessing
    179 	 * wl_count or wl_bufs or head or tail
    180 	 */
    181 
    182 #if _KERNEL
    183 	/*
    184 	 * Callback called from within the flush routine to flush any extra
    185 	 * bits.  Note that flush may be skipped without calling this if
    186 	 * there are no outstanding buffers in the transaction.
    187 	 */
    188 	wapbl_flush_fn_t wl_flush;	/* r	*/
    189 	wapbl_flush_fn_t wl_flush_abort;/* r	*/
    190 
    191 	/* Event counters */
    192 	char wl_ev_group[EVCNT_STRING_MAX];	/* r	*/
    193 	struct evcnt wl_ev_commit;		/* l	*/
    194 	struct evcnt wl_ev_journalwrite;	/* l	*/
    195 	struct evcnt wl_ev_jbufs_bio_nowait;	/* l	*/
    196 	struct evcnt wl_ev_metawrite;		/* lm	*/
    197 	struct evcnt wl_ev_cacheflush;		/* l	*/
    198 #endif
    199 
    200 	size_t wl_bufbytes;	/* m:	Byte count of pages in wl_bufs */
    201 	size_t wl_bufcount;	/* m:	Count of buffers in wl_bufs */
    202 	size_t wl_bcount;	/* m:	Total bcount of wl_bufs */
    203 
    204 	TAILQ_HEAD(, buf) wl_bufs; /* m: Buffers in current transaction */
    205 
    206 	kcondvar_t wl_reclaimable_cv;	/* m (obviously) */
    207 	size_t wl_reclaimable_bytes; /* m:	Amount of space available for
    208 						reclamation by truncate */
    209 	int wl_error_count;	/* m:	# of wl_entries with errors */
    210 	size_t wl_reserved_bytes; /* never truncate log smaller than this */
    211 
    212 #ifdef WAPBL_DEBUG_BUFBYTES
    213 	size_t wl_unsynced_bufbytes; /* Byte count of unsynced buffers */
    214 #endif
    215 
    216 #if _KERNEL
    217 	int wl_brperjblock;	/* r Block records per journal block */
    218 #endif
    219 
    220 	TAILQ_HEAD(, wapbl_dealloc) wl_dealloclist;	/* lm:	list head */
    221 	int wl_dealloccnt;				/* lm:	total count */
    222 	int wl_dealloclim;				/* r:	max count */
    223 
    224 	/* hashtable of inode numbers for allocated but unlinked inodes */
    225 	/* synch ??? */
    226 	struct wapbl_ino_head *wl_inohash;
    227 	u_long wl_inohashmask;
    228 	int wl_inohashcnt;
    229 
    230 	SIMPLEQ_HEAD(, wapbl_entry) wl_entries; /* On disk transaction
    231 						   accounting */
    232 
    233 	/* buffers for wapbl_buffered_write() */
    234 	TAILQ_HEAD(, buf) wl_iobufs;		/* l: Free or filling bufs */
    235 	TAILQ_HEAD(, buf) wl_iobufs_busy;	/* l: In-transit bufs */
    236 
    237 	int wl_dkcache;		/* r: 	disk cache flags */
    238 #define WAPBL_USE_FUA(wl)	\
    239 		(wapbl_allow_dpofua && ISSET((wl)->wl_dkcache, DKCACHE_FUA))
    240 #define WAPBL_JFLAGS(wl)	\
    241 		(WAPBL_USE_FUA(wl) ? (wl)->wl_jwrite_flags : 0)
    242 #define WAPBL_MFLAGS(wl)	\
    243 		(WAPBL_USE_FUA(wl) ? (wl)->wl_mwrite_flags : 0)
    244 	int wl_jwrite_flags;	/* r: 	journal write flags */
    245 	int wl_mwrite_flags;	/* r:	metadata write flags */
    246 };
    247 
    248 #ifdef WAPBL_DEBUG_PRINT
    249 int wapbl_debug_print = WAPBL_DEBUG_PRINT;
    250 #endif
    251 
    252 /****************************************************************/
    253 #ifdef _KERNEL
    254 
    255 #ifdef WAPBL_DEBUG
    256 struct wapbl *wapbl_debug_wl;
    257 #endif
    258 
    259 static int wapbl_write_commit(struct wapbl *wl, off_t head, off_t tail);
    260 static int wapbl_write_blocks(struct wapbl *wl, off_t *offp);
    261 static int wapbl_write_revocations(struct wapbl *wl, off_t *offp);
    262 static int wapbl_write_inodes(struct wapbl *wl, off_t *offp);
    263 #endif /* _KERNEL */
    264 
    265 static int wapbl_replay_process(struct wapbl_replay *wr, off_t, off_t);
    266 
    267 static inline size_t wapbl_space_used(size_t avail, off_t head,
    268 	off_t tail);
    269 
    270 #ifdef _KERNEL
    271 
    272 static struct pool wapbl_entry_pool;
    273 static struct pool wapbl_dealloc_pool;
    274 
    275 #define	WAPBL_INODETRK_SIZE 83
    276 static int wapbl_ino_pool_refcount;
    277 static struct pool wapbl_ino_pool;
    278 struct wapbl_ino {
    279 	LIST_ENTRY(wapbl_ino) wi_hash;
    280 	ino_t wi_ino;
    281 	mode_t wi_mode;
    282 };
    283 
    284 static void wapbl_inodetrk_init(struct wapbl *wl, u_int size);
    285 static void wapbl_inodetrk_free(struct wapbl *wl);
    286 static struct wapbl_ino *wapbl_inodetrk_get(struct wapbl *wl, ino_t ino);
    287 
    288 static size_t wapbl_transaction_len(struct wapbl *wl);
    289 static inline size_t wapbl_transaction_inodes_len(struct wapbl *wl);
    290 
    291 static void wapbl_deallocation_free(struct wapbl *, struct wapbl_dealloc *,
    292 	bool);
    293 
    294 static void wapbl_evcnt_init(struct wapbl *);
    295 static void wapbl_evcnt_free(struct wapbl *);
    296 
    297 static void wapbl_dkcache_init(struct wapbl *);
    298 
    299 #if 0
    300 int wapbl_replay_verify(struct wapbl_replay *, struct vnode *);
    301 #endif
    302 
    303 static int wapbl_replay_isopen1(struct wapbl_replay *);
    304 
    305 struct wapbl_ops wapbl_ops = {
    306 	.wo_wapbl_discard	= wapbl_discard,
    307 	.wo_wapbl_replay_isopen	= wapbl_replay_isopen1,
    308 	.wo_wapbl_replay_can_read = wapbl_replay_can_read,
    309 	.wo_wapbl_replay_read	= wapbl_replay_read,
    310 	.wo_wapbl_add_buf	= wapbl_add_buf,
    311 	.wo_wapbl_remove_buf	= wapbl_remove_buf,
    312 	.wo_wapbl_resize_buf	= wapbl_resize_buf,
    313 	.wo_wapbl_begin		= wapbl_begin,
    314 	.wo_wapbl_end		= wapbl_end,
    315 	.wo_wapbl_junlock_assert= wapbl_junlock_assert,
    316 
    317 	/* XXX: the following is only used to say "this is a wapbl buf" */
    318 	.wo_wapbl_biodone	= wapbl_biodone,
    319 };
    320 
    321 static int
    322 wapbl_sysctl_init(void)
    323 {
    324 	int rv;
    325 	const struct sysctlnode *rnode, *cnode;
    326 
    327 	wapbl_sysctl = NULL;
    328 
    329 	rv = sysctl_createv(&wapbl_sysctl, 0, NULL, &rnode,
    330 		       CTLFLAG_PERMANENT,
    331 		       CTLTYPE_NODE, "wapbl",
    332 		       SYSCTL_DESCR("WAPBL journaling options"),
    333 		       NULL, 0, NULL, 0,
    334 		       CTL_VFS, CTL_CREATE, CTL_EOL);
    335 	if (rv)
    336 		return rv;
    337 
    338 	rv = sysctl_createv(&wapbl_sysctl, 0, &rnode, &cnode,
    339 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    340 		       CTLTYPE_INT, "flush_disk_cache",
    341 		       SYSCTL_DESCR("flush disk cache"),
    342 		       NULL, 0, &wapbl_flush_disk_cache, 0,
    343 		       CTL_CREATE, CTL_EOL);
    344 	if (rv)
    345 		return rv;
    346 
    347 	rv = sysctl_createv(&wapbl_sysctl, 0, &rnode, &cnode,
    348 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    349 		       CTLTYPE_INT, "verbose_commit",
    350 		       SYSCTL_DESCR("show time and size of wapbl log commits"),
    351 		       NULL, 0, &wapbl_verbose_commit, 0,
    352 		       CTL_CREATE, CTL_EOL);
    353 	if (rv)
    354 		return rv;
    355 
    356 	rv = sysctl_createv(&wapbl_sysctl, 0, &rnode, &cnode,
    357 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    358 		       CTLTYPE_INT, "allow_dpofua",
    359 		       SYSCTL_DESCR("allow use of FUA/DPO instead of cash flush if available"),
    360 		       NULL, 0, &wapbl_allow_dpofua, 0,
    361 		       CTL_CREATE, CTL_EOL);
    362 	if (rv)
    363 		return rv;
    364 
    365 	rv = sysctl_createv(&wapbl_sysctl, 0, &rnode, &cnode,
    366 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    367 		       CTLTYPE_INT, "journal_iobufs",
    368 		       SYSCTL_DESCR("count of bufs used for journal I/O (max async count)"),
    369 		       NULL, 0, &wapbl_journal_iobufs, 0,
    370 		       CTL_CREATE, CTL_EOL);
    371 	if (rv)
    372 		return rv;
    373 
    374 	return rv;
    375 }
    376 
    377 static void
    378 wapbl_init(void)
    379 {
    380 
    381 	pool_init(&wapbl_entry_pool, sizeof(struct wapbl_entry), 0, 0, 0,
    382 	    "wapblentrypl", &pool_allocator_kmem, IPL_VM);
    383 	pool_init(&wapbl_dealloc_pool, sizeof(struct wapbl_dealloc), 0, 0, 0,
    384 	    "wapbldealloc", &pool_allocator_nointr, IPL_NONE);
    385 
    386 	wapbl_sysctl_init();
    387 }
    388 
    389 static int
    390 wapbl_fini(void)
    391 {
    392 
    393 	if (wapbl_sysctl != NULL)
    394 		 sysctl_teardown(&wapbl_sysctl);
    395 
    396 	pool_destroy(&wapbl_dealloc_pool);
    397 	pool_destroy(&wapbl_entry_pool);
    398 
    399 	return 0;
    400 }
    401 
    402 static void
    403 wapbl_evcnt_init(struct wapbl *wl)
    404 {
    405 	snprintf(wl->wl_ev_group, sizeof(wl->wl_ev_group),
    406 	    "wapbl fsid 0x%x/0x%x",
    407 	    wl->wl_mount->mnt_stat.f_fsidx.__fsid_val[0],
    408 	    wl->wl_mount->mnt_stat.f_fsidx.__fsid_val[1]
    409 	);
    410 
    411 	evcnt_attach_dynamic(&wl->wl_ev_commit, EVCNT_TYPE_MISC,
    412 	    NULL, wl->wl_ev_group, "commit");
    413 	evcnt_attach_dynamic(&wl->wl_ev_journalwrite, EVCNT_TYPE_MISC,
    414 	    NULL, wl->wl_ev_group, "journal write total");
    415 	evcnt_attach_dynamic(&wl->wl_ev_jbufs_bio_nowait, EVCNT_TYPE_MISC,
    416 	    NULL, wl->wl_ev_group, "journal write finished async");
    417 	evcnt_attach_dynamic(&wl->wl_ev_metawrite, EVCNT_TYPE_MISC,
    418 	    NULL, wl->wl_ev_group, "metadata async write");
    419 	evcnt_attach_dynamic(&wl->wl_ev_cacheflush, EVCNT_TYPE_MISC,
    420 	    NULL, wl->wl_ev_group, "cache flush");
    421 }
    422 
    423 static void
    424 wapbl_evcnt_free(struct wapbl *wl)
    425 {
    426 	evcnt_detach(&wl->wl_ev_commit);
    427 	evcnt_detach(&wl->wl_ev_journalwrite);
    428 	evcnt_detach(&wl->wl_ev_jbufs_bio_nowait);
    429 	evcnt_detach(&wl->wl_ev_metawrite);
    430 	evcnt_detach(&wl->wl_ev_cacheflush);
    431 }
    432 
    433 static void
    434 wapbl_dkcache_init(struct wapbl *wl)
    435 {
    436 	int error;
    437 
    438 	/* Get disk cache flags */
    439 	error = VOP_IOCTL(wl->wl_devvp, DIOCGCACHE, &wl->wl_dkcache,
    440 	    FWRITE, FSCRED);
    441 	if (error) {
    442 		/* behave as if there was a write cache */
    443 		wl->wl_dkcache = DKCACHE_WRITE;
    444 	}
    445 
    446 	/* Use FUA instead of cache flush if available */
    447 	if (ISSET(wl->wl_dkcache, DKCACHE_FUA)) {
    448 		wl->wl_jwrite_flags |= B_MEDIA_FUA;
    449 		wl->wl_mwrite_flags |= B_MEDIA_FUA;
    450 	}
    451 
    452 	/* Use DPO for journal writes if available */
    453 	if (ISSET(wl->wl_dkcache, DKCACHE_DPO))
    454 		wl->wl_jwrite_flags |= B_MEDIA_DPO;
    455 }
    456 
    457 static int
    458 wapbl_start_flush_inodes(struct wapbl *wl, struct wapbl_replay *wr)
    459 {
    460 	int error, i;
    461 
    462 	WAPBL_PRINTF(WAPBL_PRINT_REPLAY,
    463 	    ("wapbl_start: reusing log with %d inodes\n", wr->wr_inodescnt));
    464 
    465 	/*
    466 	 * Its only valid to reuse the replay log if its
    467 	 * the same as the new log we just opened.
    468 	 */
    469 	KDASSERT(!wapbl_replay_isopen(wr));
    470 	KASSERT(wl->wl_devvp->v_type == VBLK);
    471 	KASSERT(wr->wr_devvp->v_type == VBLK);
    472 	KASSERT(wl->wl_devvp->v_rdev == wr->wr_devvp->v_rdev);
    473 	KASSERT(wl->wl_logpbn == wr->wr_logpbn);
    474 	KASSERT(wl->wl_circ_size == wr->wr_circ_size);
    475 	KASSERT(wl->wl_circ_off == wr->wr_circ_off);
    476 	KASSERT(wl->wl_log_dev_bshift == wr->wr_log_dev_bshift);
    477 	KASSERT(wl->wl_fs_dev_bshift == wr->wr_fs_dev_bshift);
    478 
    479 	wl->wl_wc_header->wc_generation = wr->wr_generation + 1;
    480 
    481 	for (i = 0; i < wr->wr_inodescnt; i++)
    482 		wapbl_register_inode(wl, wr->wr_inodes[i].wr_inumber,
    483 		    wr->wr_inodes[i].wr_imode);
    484 
    485 	/* Make sure new transaction won't overwrite old inodes list */
    486 	KDASSERT(wapbl_transaction_len(wl) <=
    487 	    wapbl_space_free(wl->wl_circ_size, wr->wr_inodeshead,
    488 	    wr->wr_inodestail));
    489 
    490 	wl->wl_head = wl->wl_tail = wr->wr_inodeshead;
    491 	wl->wl_reclaimable_bytes = wl->wl_reserved_bytes =
    492 	    wapbl_transaction_len(wl);
    493 
    494 	error = wapbl_write_inodes(wl, &wl->wl_head);
    495 	if (error)
    496 		return error;
    497 
    498 	KASSERT(wl->wl_head != wl->wl_tail);
    499 	KASSERT(wl->wl_head != 0);
    500 
    501 	return 0;
    502 }
    503 
    504 int
    505 wapbl_start(struct wapbl ** wlp, struct mount *mp, struct vnode *vp,
    506 	daddr_t off, size_t count, size_t blksize, struct wapbl_replay *wr,
    507 	wapbl_flush_fn_t flushfn, wapbl_flush_fn_t flushabortfn)
    508 {
    509 	struct wapbl *wl;
    510 	struct vnode *devvp;
    511 	daddr_t logpbn;
    512 	int error;
    513 	int log_dev_bshift = ilog2(blksize);
    514 	int fs_dev_bshift = log_dev_bshift;
    515 	int run;
    516 
    517 	WAPBL_PRINTF(WAPBL_PRINT_OPEN, ("wapbl_start: vp=%p off=%" PRId64
    518 	    " count=%zu blksize=%zu\n", vp, off, count, blksize));
    519 
    520 	if (log_dev_bshift > fs_dev_bshift) {
    521 		WAPBL_PRINTF(WAPBL_PRINT_OPEN,
    522 			("wapbl: log device's block size cannot be larger "
    523 			 "than filesystem's\n"));
    524 		/*
    525 		 * Not currently implemented, although it could be if
    526 		 * needed someday.
    527 		 */
    528 		return ENOSYS;
    529 	}
    530 
    531 	if (off < 0)
    532 		return EINVAL;
    533 
    534 	if (blksize < DEV_BSIZE)
    535 		return EINVAL;
    536 	if (blksize % DEV_BSIZE)
    537 		return EINVAL;
    538 
    539 	/* XXXTODO: verify that the full load is writable */
    540 
    541 	/*
    542 	 * XXX check for minimum log size
    543 	 * minimum is governed by minimum amount of space
    544 	 * to complete a transaction. (probably truncate)
    545 	 */
    546 	/* XXX for now pick something minimal */
    547 	if ((count * blksize) < MAXPHYS) {
    548 		return ENOSPC;
    549 	}
    550 
    551 	if ((error = VOP_BMAP(vp, off, &devvp, &logpbn, &run)) != 0) {
    552 		return error;
    553 	}
    554 
    555 	wl = wapbl_calloc(1, sizeof(*wl));
    556 	rw_init(&wl->wl_rwlock);
    557 	mutex_init(&wl->wl_mtx, MUTEX_DEFAULT, IPL_NONE);
    558 	cv_init(&wl->wl_reclaimable_cv, "wapblrec");
    559 	TAILQ_INIT(&wl->wl_bufs);
    560 	SIMPLEQ_INIT(&wl->wl_entries);
    561 
    562 	wl->wl_logvp = vp;
    563 	wl->wl_devvp = devvp;
    564 	wl->wl_mount = mp;
    565 	wl->wl_logpbn = logpbn;
    566 	wl->wl_log_dev_bshift = log_dev_bshift;
    567 	wl->wl_fs_dev_bshift = fs_dev_bshift;
    568 
    569 	wl->wl_flush = flushfn;
    570 	wl->wl_flush_abort = flushabortfn;
    571 
    572 	/* Reserve two log device blocks for the commit headers */
    573 	wl->wl_circ_off = 2<<wl->wl_log_dev_bshift;
    574 	wl->wl_circ_size = ((count * blksize) - wl->wl_circ_off);
    575 	/* truncate the log usage to a multiple of log_dev_bshift */
    576 	wl->wl_circ_size >>= wl->wl_log_dev_bshift;
    577 	wl->wl_circ_size <<= wl->wl_log_dev_bshift;
    578 
    579 	/*
    580 	 * wl_bufbytes_max limits the size of the in memory transaction space.
    581 	 * - Since buffers are allocated and accounted for in units of
    582 	 *   PAGE_SIZE it is required to be a multiple of PAGE_SIZE
    583 	 *   (i.e. 1<<PAGE_SHIFT)
    584 	 * - Since the log device has to be written in units of
    585 	 *   1<<wl_log_dev_bshift it is required to be a mulitple of
    586 	 *   1<<wl_log_dev_bshift.
    587 	 * - Since filesystem will provide data in units of 1<<wl_fs_dev_bshift,
    588 	 *   it is convenient to be a multiple of 1<<wl_fs_dev_bshift.
    589 	 * Therefore it must be multiple of the least common multiple of those
    590 	 * three quantities.  Fortunately, all of those quantities are
    591 	 * guaranteed to be a power of two, and the least common multiple of
    592 	 * a set of numbers which are all powers of two is simply the maximum
    593 	 * of those numbers.  Finally, the maximum logarithm of a power of two
    594 	 * is the same as the log of the maximum power of two.  So we can do
    595 	 * the following operations to size wl_bufbytes_max:
    596 	 */
    597 
    598 	/* XXX fix actual number of pages reserved per filesystem. */
    599 	wl->wl_bufbytes_max = MIN(wl->wl_circ_size, buf_memcalc() / 2);
    600 
    601 	/* Round wl_bufbytes_max to the largest power of two constraint */
    602 	wl->wl_bufbytes_max >>= PAGE_SHIFT;
    603 	wl->wl_bufbytes_max <<= PAGE_SHIFT;
    604 	wl->wl_bufbytes_max >>= wl->wl_log_dev_bshift;
    605 	wl->wl_bufbytes_max <<= wl->wl_log_dev_bshift;
    606 	wl->wl_bufbytes_max >>= wl->wl_fs_dev_bshift;
    607 	wl->wl_bufbytes_max <<= wl->wl_fs_dev_bshift;
    608 
    609 	/* XXX maybe use filesystem fragment size instead of 1024 */
    610 	/* XXX fix actual number of buffers reserved per filesystem. */
    611 	wl->wl_bufcount_max = (buf_nbuf() / 2) * 1024;
    612 
    613 	wl->wl_brperjblock = ((1<<wl->wl_log_dev_bshift)
    614 	    - offsetof(struct wapbl_wc_blocklist, wc_blocks)) /
    615 	    sizeof(((struct wapbl_wc_blocklist *)0)->wc_blocks[0]);
    616 	KASSERT(wl->wl_brperjblock > 0);
    617 
    618 	/* XXX tie this into resource estimation */
    619 	wl->wl_dealloclim = wl->wl_bufbytes_max / mp->mnt_stat.f_bsize / 2;
    620 	TAILQ_INIT(&wl->wl_dealloclist);
    621 
    622 	wapbl_inodetrk_init(wl, WAPBL_INODETRK_SIZE);
    623 
    624 	wapbl_evcnt_init(wl);
    625 
    626 	wapbl_dkcache_init(wl);
    627 
    628 	/* Initialize the commit header */
    629 	{
    630 		struct wapbl_wc_header *wc;
    631 		size_t len = 1 << wl->wl_log_dev_bshift;
    632 		wc = wapbl_calloc(1, len);
    633 		wc->wc_type = WAPBL_WC_HEADER;
    634 		wc->wc_len = len;
    635 		wc->wc_circ_off = wl->wl_circ_off;
    636 		wc->wc_circ_size = wl->wl_circ_size;
    637 		/* XXX wc->wc_fsid */
    638 		wc->wc_log_dev_bshift = wl->wl_log_dev_bshift;
    639 		wc->wc_fs_dev_bshift = wl->wl_fs_dev_bshift;
    640 		wl->wl_wc_header = wc;
    641 		wl->wl_wc_scratch = wapbl_alloc(len);
    642 	}
    643 
    644 	TAILQ_INIT(&wl->wl_iobufs);
    645 	TAILQ_INIT(&wl->wl_iobufs_busy);
    646 	for (int i = 0; i < wapbl_journal_iobufs; i++) {
    647 		struct buf *bp;
    648 
    649 		if ((bp = geteblk(MAXPHYS)) == NULL)
    650 			goto errout;
    651 
    652 		mutex_enter(&bufcache_lock);
    653 		mutex_enter(devvp->v_interlock);
    654 		bgetvp(devvp, bp);
    655 		mutex_exit(devvp->v_interlock);
    656 		mutex_exit(&bufcache_lock);
    657 
    658 		bp->b_dev = devvp->v_rdev;
    659 
    660 		TAILQ_INSERT_TAIL(&wl->wl_iobufs, bp, b_wapbllist);
    661 	}
    662 
    663 	/*
    664 	 * if there was an existing set of unlinked but
    665 	 * allocated inodes, preserve it in the new
    666 	 * log.
    667 	 */
    668 	if (wr && wr->wr_inodescnt) {
    669 		error = wapbl_start_flush_inodes(wl, wr);
    670 		if (error)
    671 			goto errout;
    672 	}
    673 
    674 	error = wapbl_write_commit(wl, wl->wl_head, wl->wl_tail);
    675 	if (error) {
    676 		goto errout;
    677 	}
    678 
    679 	*wlp = wl;
    680 #if defined(WAPBL_DEBUG)
    681 	wapbl_debug_wl = wl;
    682 #endif
    683 
    684 	return 0;
    685  errout:
    686 	wapbl_discard(wl);
    687 	wapbl_free(wl->wl_wc_scratch, wl->wl_wc_header->wc_len);
    688 	wapbl_free(wl->wl_wc_header, wl->wl_wc_header->wc_len);
    689 	while (!TAILQ_EMPTY(&wl->wl_iobufs)) {
    690 		struct buf *bp;
    691 
    692 		bp = TAILQ_FIRST(&wl->wl_iobufs);
    693 		TAILQ_REMOVE(&wl->wl_iobufs, bp, b_wapbllist);
    694 		brelse(bp, BC_INVAL);
    695 	}
    696 	wapbl_inodetrk_free(wl);
    697 	wapbl_free(wl, sizeof(*wl));
    698 
    699 	return error;
    700 }
    701 
    702 /*
    703  * Like wapbl_flush, only discards the transaction
    704  * completely
    705  */
    706 
    707 void
    708 wapbl_discard(struct wapbl *wl)
    709 {
    710 	struct wapbl_entry *we;
    711 	struct wapbl_dealloc *wd;
    712 	struct buf *bp;
    713 	int i;
    714 
    715 	/*
    716 	 * XXX we may consider using upgrade here
    717 	 * if we want to call flush from inside a transaction
    718 	 */
    719 	rw_enter(&wl->wl_rwlock, RW_WRITER);
    720 	wl->wl_flush(wl->wl_mount, TAILQ_FIRST(&wl->wl_dealloclist));
    721 
    722 #ifdef WAPBL_DEBUG_PRINT
    723 	{
    724 		pid_t pid = -1;
    725 		lwpid_t lid = -1;
    726 		if (curproc)
    727 			pid = curproc->p_pid;
    728 		if (curlwp)
    729 			lid = curlwp->l_lid;
    730 #ifdef WAPBL_DEBUG_BUFBYTES
    731 		WAPBL_PRINTF(WAPBL_PRINT_DISCARD,
    732 		    ("wapbl_discard: thread %d.%d discarding "
    733 		    "transaction\n"
    734 		    "\tbufcount=%zu bufbytes=%zu bcount=%zu "
    735 		    "deallocs=%d inodes=%d\n"
    736 		    "\terrcnt = %u, reclaimable=%zu reserved=%zu "
    737 		    "unsynced=%zu\n",
    738 		    pid, lid, wl->wl_bufcount, wl->wl_bufbytes,
    739 		    wl->wl_bcount, wl->wl_dealloccnt,
    740 		    wl->wl_inohashcnt, wl->wl_error_count,
    741 		    wl->wl_reclaimable_bytes, wl->wl_reserved_bytes,
    742 		    wl->wl_unsynced_bufbytes));
    743 		SIMPLEQ_FOREACH(we, &wl->wl_entries, we_entries) {
    744 			WAPBL_PRINTF(WAPBL_PRINT_DISCARD,
    745 			    ("\tentry: bufcount = %zu, reclaimable = %zu, "
    746 			     "error = %d, unsynced = %zu\n",
    747 			     we->we_bufcount, we->we_reclaimable_bytes,
    748 			     we->we_error, we->we_unsynced_bufbytes));
    749 		}
    750 #else /* !WAPBL_DEBUG_BUFBYTES */
    751 		WAPBL_PRINTF(WAPBL_PRINT_DISCARD,
    752 		    ("wapbl_discard: thread %d.%d discarding transaction\n"
    753 		    "\tbufcount=%zu bufbytes=%zu bcount=%zu "
    754 		    "deallocs=%d inodes=%d\n"
    755 		    "\terrcnt = %u, reclaimable=%zu reserved=%zu\n",
    756 		    pid, lid, wl->wl_bufcount, wl->wl_bufbytes,
    757 		    wl->wl_bcount, wl->wl_dealloccnt,
    758 		    wl->wl_inohashcnt, wl->wl_error_count,
    759 		    wl->wl_reclaimable_bytes, wl->wl_reserved_bytes));
    760 		SIMPLEQ_FOREACH(we, &wl->wl_entries, we_entries) {
    761 			WAPBL_PRINTF(WAPBL_PRINT_DISCARD,
    762 			    ("\tentry: bufcount = %zu, reclaimable = %zu, "
    763 			     "error = %d\n",
    764 			     we->we_bufcount, we->we_reclaimable_bytes,
    765 			     we->we_error));
    766 		}
    767 #endif /* !WAPBL_DEBUG_BUFBYTES */
    768 	}
    769 #endif /* WAPBL_DEBUG_PRINT */
    770 
    771 	for (i = 0; i <= wl->wl_inohashmask; i++) {
    772 		struct wapbl_ino_head *wih;
    773 		struct wapbl_ino *wi;
    774 
    775 		wih = &wl->wl_inohash[i];
    776 		while ((wi = LIST_FIRST(wih)) != NULL) {
    777 			LIST_REMOVE(wi, wi_hash);
    778 			pool_put(&wapbl_ino_pool, wi);
    779 			KASSERT(wl->wl_inohashcnt > 0);
    780 			wl->wl_inohashcnt--;
    781 		}
    782 	}
    783 
    784 	/*
    785 	 * clean buffer list
    786 	 */
    787 	mutex_enter(&bufcache_lock);
    788 	mutex_enter(&wl->wl_mtx);
    789 	while ((bp = TAILQ_FIRST(&wl->wl_bufs)) != NULL) {
    790 		if (bbusy(bp, 0, 0, &wl->wl_mtx) == 0) {
    791 			/*
    792 			 * The buffer will be unlocked and
    793 			 * removed from the transaction in brelse
    794 			 */
    795 			mutex_exit(&wl->wl_mtx);
    796 			brelsel(bp, 0);
    797 			mutex_enter(&wl->wl_mtx);
    798 		}
    799 	}
    800 	mutex_exit(&wl->wl_mtx);
    801 	mutex_exit(&bufcache_lock);
    802 
    803 	/*
    804 	 * Remove references to this wl from wl_entries, free any which
    805 	 * no longer have buffers, others will be freed in wapbl_biodone
    806 	 * when they no longer have any buffers.
    807 	 */
    808 	while ((we = SIMPLEQ_FIRST(&wl->wl_entries)) != NULL) {
    809 		SIMPLEQ_REMOVE_HEAD(&wl->wl_entries, we_entries);
    810 		/* XXX should we be accumulating wl_error_count
    811 		 * and increasing reclaimable bytes ? */
    812 		we->we_wapbl = NULL;
    813 		if (we->we_bufcount == 0) {
    814 #ifdef WAPBL_DEBUG_BUFBYTES
    815 			KASSERT(we->we_unsynced_bufbytes == 0);
    816 #endif
    817 			pool_put(&wapbl_entry_pool, we);
    818 		}
    819 	}
    820 
    821 	/* Discard list of deallocs */
    822 	while ((wd = TAILQ_FIRST(&wl->wl_dealloclist)) != NULL)
    823 		wapbl_deallocation_free(wl, wd, true);
    824 
    825 	/* XXX should we clear wl_reserved_bytes? */
    826 
    827 	KASSERT(wl->wl_bufbytes == 0);
    828 	KASSERT(wl->wl_bcount == 0);
    829 	KASSERT(wl->wl_bufcount == 0);
    830 	KASSERT(TAILQ_EMPTY(&wl->wl_bufs));
    831 	KASSERT(SIMPLEQ_EMPTY(&wl->wl_entries));
    832 	KASSERT(wl->wl_inohashcnt == 0);
    833 	KASSERT(TAILQ_EMPTY(&wl->wl_dealloclist));
    834 	KASSERT(wl->wl_dealloccnt == 0);
    835 
    836 	rw_exit(&wl->wl_rwlock);
    837 }
    838 
    839 int
    840 wapbl_stop(struct wapbl *wl, int force)
    841 {
    842 	int error;
    843 
    844 	WAPBL_PRINTF(WAPBL_PRINT_OPEN, ("wapbl_stop called\n"));
    845 	error = wapbl_flush(wl, 1);
    846 	if (error) {
    847 		if (force)
    848 			wapbl_discard(wl);
    849 		else
    850 			return error;
    851 	}
    852 
    853 	/* Unlinked inodes persist after a flush */
    854 	if (wl->wl_inohashcnt) {
    855 		if (force) {
    856 			wapbl_discard(wl);
    857 		} else {
    858 			return EBUSY;
    859 		}
    860 	}
    861 
    862 	KASSERT(wl->wl_bufbytes == 0);
    863 	KASSERT(wl->wl_bcount == 0);
    864 	KASSERT(wl->wl_bufcount == 0);
    865 	KASSERT(TAILQ_EMPTY(&wl->wl_bufs));
    866 	KASSERT(wl->wl_dealloccnt == 0);
    867 	KASSERT(SIMPLEQ_EMPTY(&wl->wl_entries));
    868 	KASSERT(wl->wl_inohashcnt == 0);
    869 	KASSERT(TAILQ_EMPTY(&wl->wl_dealloclist));
    870 	KASSERT(wl->wl_dealloccnt == 0);
    871 	KASSERT(TAILQ_EMPTY(&wl->wl_iobufs_busy));
    872 
    873 	wapbl_free(wl->wl_wc_scratch, wl->wl_wc_header->wc_len);
    874 	wapbl_free(wl->wl_wc_header, wl->wl_wc_header->wc_len);
    875 	while (!TAILQ_EMPTY(&wl->wl_iobufs)) {
    876 		struct buf *bp;
    877 
    878 		bp = TAILQ_FIRST(&wl->wl_iobufs);
    879 		TAILQ_REMOVE(&wl->wl_iobufs, bp, b_wapbllist);
    880 		brelse(bp, BC_INVAL);
    881 	}
    882 	wapbl_inodetrk_free(wl);
    883 
    884 	wapbl_evcnt_free(wl);
    885 
    886 	cv_destroy(&wl->wl_reclaimable_cv);
    887 	mutex_destroy(&wl->wl_mtx);
    888 	rw_destroy(&wl->wl_rwlock);
    889 	wapbl_free(wl, sizeof(*wl));
    890 
    891 	return 0;
    892 }
    893 
    894 /****************************************************************/
    895 /*
    896  * Unbuffered disk I/O
    897  */
    898 
    899 static void
    900 wapbl_doio_accounting(struct vnode *devvp, int flags)
    901 {
    902 	struct pstats *pstats = curlwp->l_proc->p_stats;
    903 
    904 	if ((flags & (B_WRITE | B_READ)) == B_WRITE) {
    905 		mutex_enter(devvp->v_interlock);
    906 		devvp->v_numoutput++;
    907 		mutex_exit(devvp->v_interlock);
    908 		pstats->p_ru.ru_oublock++;
    909 	} else {
    910 		pstats->p_ru.ru_inblock++;
    911 	}
    912 
    913 }
    914 
    915 static int
    916 wapbl_doio(void *data, size_t len, struct vnode *devvp, daddr_t pbn, int flags)
    917 {
    918 	struct buf *bp;
    919 	int error;
    920 
    921 	KASSERT(devvp->v_type == VBLK);
    922 
    923 	wapbl_doio_accounting(devvp, flags);
    924 
    925 	bp = getiobuf(devvp, true);
    926 	bp->b_flags = flags;
    927 	bp->b_cflags = BC_BUSY;	/* mandatory, asserted by biowait() */
    928 	bp->b_dev = devvp->v_rdev;
    929 	bp->b_data = data;
    930 	bp->b_bufsize = bp->b_resid = bp->b_bcount = len;
    931 	bp->b_blkno = pbn;
    932 	BIO_SETPRIO(bp, BPRIO_TIMECRITICAL);
    933 
    934 	WAPBL_PRINTF(WAPBL_PRINT_IO,
    935 	    ("wapbl_doio: %s %d bytes at block %"PRId64" on dev 0x%"PRIx64"\n",
    936 	    BUF_ISWRITE(bp) ? "write" : "read", bp->b_bcount,
    937 	    bp->b_blkno, bp->b_dev));
    938 
    939 	VOP_STRATEGY(devvp, bp);
    940 
    941 	error = biowait(bp);
    942 	putiobuf(bp);
    943 
    944 	if (error) {
    945 		WAPBL_PRINTF(WAPBL_PRINT_ERROR,
    946 		    ("wapbl_doio: %s %zu bytes at block %" PRId64
    947 		    " on dev 0x%"PRIx64" failed with error %d\n",
    948 		    (((flags & (B_WRITE | B_READ)) == B_WRITE) ?
    949 		     "write" : "read"),
    950 		    len, pbn, devvp->v_rdev, error));
    951 	}
    952 
    953 	return error;
    954 }
    955 
    956 /*
    957  * wapbl_write(data, len, devvp, pbn)
    958  *
    959  *	Synchronously write len bytes from data to physical block pbn
    960  *	on devvp.
    961  */
    962 int
    963 wapbl_write(void *data, size_t len, struct vnode *devvp, daddr_t pbn)
    964 {
    965 
    966 	return wapbl_doio(data, len, devvp, pbn, B_WRITE);
    967 }
    968 
    969 /*
    970  * wapbl_read(data, len, devvp, pbn)
    971  *
    972  *	Synchronously read len bytes into data from physical block pbn
    973  *	on devvp.
    974  */
    975 int
    976 wapbl_read(void *data, size_t len, struct vnode *devvp, daddr_t pbn)
    977 {
    978 
    979 	return wapbl_doio(data, len, devvp, pbn, B_READ);
    980 }
    981 
    982 /****************************************************************/
    983 /*
    984  * Buffered disk writes -- try to coalesce writes and emit
    985  * MAXPHYS-aligned blocks.
    986  */
    987 
    988 /*
    989  * wapbl_buffered_write_async(wl, bp)
    990  *
    991  *	Send buffer for asynchronous write.
    992  */
    993 static void
    994 wapbl_buffered_write_async(struct wapbl *wl, struct buf *bp)
    995 {
    996 	wapbl_doio_accounting(wl->wl_devvp, bp->b_flags);
    997 
    998 	KASSERT(TAILQ_FIRST(&wl->wl_iobufs) == bp);
    999 	TAILQ_REMOVE(&wl->wl_iobufs, bp, b_wapbllist);
   1000 
   1001 	bp->b_flags = B_WRITE | WAPBL_JFLAGS(wl);
   1002 	bp->b_cflags = BC_BUSY;	/* mandatory, asserted by biowait() */
   1003 	bp->b_oflags = 0;
   1004 	bp->b_bcount = bp->b_resid;
   1005 	BIO_SETPRIO(bp, BPRIO_TIMECRITICAL);
   1006 
   1007 	VOP_STRATEGY(wl->wl_devvp, bp);
   1008 
   1009 	wl->wl_ev_journalwrite.ev_count++;
   1010 
   1011 	TAILQ_INSERT_TAIL(&wl->wl_iobufs_busy, bp, b_wapbllist);
   1012 }
   1013 
   1014 /*
   1015  * wapbl_buffered_flush(wl)
   1016  *
   1017  *	Flush any buffered writes from wapbl_buffered_write.
   1018  */
   1019 static int
   1020 wapbl_buffered_flush(struct wapbl *wl, bool full)
   1021 {
   1022 	int error = 0;
   1023 	struct buf *bp, *bnext;
   1024 	bool only_done = true, found = false;
   1025 
   1026 	/* if there is outstanding buffered write, send it now */
   1027 	if ((bp = TAILQ_FIRST(&wl->wl_iobufs)) && bp->b_resid > 0)
   1028 		wapbl_buffered_write_async(wl, bp);
   1029 
   1030 	/* wait for I/O to complete */
   1031 again:
   1032 	TAILQ_FOREACH_SAFE(bp, &wl->wl_iobufs_busy, b_wapbllist, bnext) {
   1033 		if (!full && only_done) {
   1034 			/* skip unfinished */
   1035 			if (!ISSET(bp->b_oflags, BO_DONE))
   1036 				continue;
   1037 		}
   1038 
   1039 		if (ISSET(bp->b_oflags, BO_DONE))
   1040 			wl->wl_ev_jbufs_bio_nowait.ev_count++;
   1041 
   1042 		TAILQ_REMOVE(&wl->wl_iobufs_busy, bp, b_wapbllist);
   1043 		error = biowait(bp);
   1044 
   1045 		/* reset for reuse */
   1046 		bp->b_blkno = bp->b_resid = 0;
   1047 		TAILQ_INSERT_TAIL(&wl->wl_iobufs, bp, b_wapbllist);
   1048 		found = true;
   1049 
   1050 		if (!full)
   1051 			break;
   1052 	}
   1053 
   1054 	if (!found && only_done && !TAILQ_EMPTY(&wl->wl_iobufs_busy)) {
   1055 		only_done = false;
   1056 		goto again;
   1057 	}
   1058 
   1059 	return error;
   1060 }
   1061 
   1062 /*
   1063  * wapbl_buffered_write(data, len, wl, pbn)
   1064  *
   1065  *	Write len bytes from data to physical block pbn on
   1066  *	wl->wl_devvp.  The write may not complete until
   1067  *	wapbl_buffered_flush.
   1068  */
   1069 static int
   1070 wapbl_buffered_write(void *data, size_t len, struct wapbl *wl, daddr_t pbn)
   1071 {
   1072 	size_t resid;
   1073 	struct buf *bp;
   1074 
   1075 again:
   1076 	bp = TAILQ_FIRST(&wl->wl_iobufs);
   1077 
   1078 	if (bp == NULL) {
   1079 		/* No more buffers, wait for any previous I/O to finish. */
   1080 		wapbl_buffered_flush(wl, false);
   1081 
   1082 		bp = TAILQ_FIRST(&wl->wl_iobufs);
   1083 		KASSERT(bp != NULL);
   1084 	}
   1085 
   1086 	/*
   1087 	 * If not adjacent to buffered data flush first.  Disk block
   1088 	 * address is always valid for non-empty buffer.
   1089 	 */
   1090 	if ((bp->b_resid > 0 && pbn != bp->b_blkno + btodb(bp->b_resid))) {
   1091 		wapbl_buffered_write_async(wl, bp);
   1092 		goto again;
   1093 	}
   1094 
   1095 	/*
   1096 	 * If this write goes to an empty buffer we have to
   1097 	 * save the disk block address first.
   1098 	 */
   1099 	if (bp->b_blkno == 0)
   1100 		bp->b_blkno = pbn;
   1101 
   1102 	/*
   1103 	 * Remaining space so this buffer ends on a buffer size boundary.
   1104 	 *
   1105 	 * Cannot become less or equal zero as the buffer would have been
   1106 	 * flushed on the last call then.
   1107 	 */
   1108 	resid = bp->b_bufsize - dbtob(bp->b_blkno % btodb(bp->b_bufsize)) -
   1109 	    bp->b_resid;
   1110 	KASSERT(resid > 0);
   1111 	KASSERT(dbtob(btodb(resid)) == resid);
   1112 
   1113 	if (len < resid)
   1114 		resid = len;
   1115 
   1116 	memcpy((uint8_t *)bp->b_data + bp->b_resid, data, resid);
   1117 	bp->b_resid += resid;
   1118 
   1119 	if (len >= resid) {
   1120 		/* Just filled the buf, or data did not fit */
   1121 		wapbl_buffered_write_async(wl, bp);
   1122 
   1123 		data = (uint8_t *)data + resid;
   1124 		len -= resid;
   1125 		pbn += btodb(resid);
   1126 
   1127 		if (len > 0)
   1128 			goto again;
   1129 	}
   1130 
   1131 	return 0;
   1132 }
   1133 
   1134 /*
   1135  * wapbl_circ_write(wl, data, len, offp)
   1136  *
   1137  *	Write len bytes from data to the circular queue of wl, starting
   1138  *	at linear byte offset *offp, and returning the new linear byte
   1139  *	offset in *offp.
   1140  *
   1141  *	If the starting linear byte offset precedes wl->wl_circ_off,
   1142  *	the write instead begins at wl->wl_circ_off.  XXX WTF?  This
   1143  *	should be a KASSERT, not a conditional.
   1144  *
   1145  *	The write is buffered in wl and must be flushed with
   1146  *	wapbl_buffered_flush before it will be submitted to the disk.
   1147  */
   1148 static int
   1149 wapbl_circ_write(struct wapbl *wl, void *data, size_t len, off_t *offp)
   1150 {
   1151 	size_t slen;
   1152 	off_t off = *offp;
   1153 	int error;
   1154 	daddr_t pbn;
   1155 
   1156 	KDASSERT(((len >> wl->wl_log_dev_bshift) <<
   1157 	    wl->wl_log_dev_bshift) == len);
   1158 
   1159 	if (off < wl->wl_circ_off)
   1160 		off = wl->wl_circ_off;
   1161 	slen = wl->wl_circ_off + wl->wl_circ_size - off;
   1162 	if (slen < len) {
   1163 		pbn = wl->wl_logpbn + (off >> wl->wl_log_dev_bshift);
   1164 #ifdef _KERNEL
   1165 		pbn = btodb(pbn << wl->wl_log_dev_bshift);
   1166 #endif
   1167 		error = wapbl_buffered_write(data, slen, wl, pbn);
   1168 		if (error)
   1169 			return error;
   1170 		data = (uint8_t *)data + slen;
   1171 		len -= slen;
   1172 		off = wl->wl_circ_off;
   1173 	}
   1174 	pbn = wl->wl_logpbn + (off >> wl->wl_log_dev_bshift);
   1175 #ifdef _KERNEL
   1176 	pbn = btodb(pbn << wl->wl_log_dev_bshift);
   1177 #endif
   1178 	error = wapbl_buffered_write(data, len, wl, pbn);
   1179 	if (error)
   1180 		return error;
   1181 	off += len;
   1182 	if (off >= wl->wl_circ_off + wl->wl_circ_size)
   1183 		off = wl->wl_circ_off;
   1184 	*offp = off;
   1185 	return 0;
   1186 }
   1187 
   1188 /****************************************************************/
   1189 /*
   1190  * WAPBL transactions: entering, adding/removing bufs, and exiting
   1191  */
   1192 
   1193 int
   1194 wapbl_begin(struct wapbl *wl, const char *file, int line)
   1195 {
   1196 	int doflush;
   1197 	unsigned lockcount;
   1198 
   1199 	KDASSERT(wl);
   1200 
   1201 	/*
   1202 	 * XXX this needs to be made much more sophisticated.
   1203 	 * perhaps each wapbl_begin could reserve a specified
   1204 	 * number of buffers and bytes.
   1205 	 */
   1206 	mutex_enter(&wl->wl_mtx);
   1207 	lockcount = wl->wl_lock_count;
   1208 	doflush = ((wl->wl_bufbytes + (lockcount * MAXPHYS)) >
   1209 		   wl->wl_bufbytes_max / 2) ||
   1210 		  ((wl->wl_bufcount + (lockcount * 10)) >
   1211 		   wl->wl_bufcount_max / 2) ||
   1212 		  (wapbl_transaction_len(wl) > wl->wl_circ_size / 2) ||
   1213 		  (wl->wl_dealloccnt >= (wl->wl_dealloclim / 2));
   1214 	mutex_exit(&wl->wl_mtx);
   1215 
   1216 	if (doflush) {
   1217 		WAPBL_PRINTF(WAPBL_PRINT_FLUSH,
   1218 		    ("force flush lockcnt=%d bufbytes=%zu "
   1219 		    "(max=%zu) bufcount=%zu (max=%zu) "
   1220 		    "dealloccnt %d (lim=%d)\n",
   1221 		    lockcount, wl->wl_bufbytes,
   1222 		    wl->wl_bufbytes_max, wl->wl_bufcount,
   1223 		    wl->wl_bufcount_max,
   1224 		    wl->wl_dealloccnt, wl->wl_dealloclim));
   1225 	}
   1226 
   1227 	if (doflush) {
   1228 		int error = wapbl_flush(wl, 0);
   1229 		if (error)
   1230 			return error;
   1231 	}
   1232 
   1233 	rw_enter(&wl->wl_rwlock, RW_READER);
   1234 	mutex_enter(&wl->wl_mtx);
   1235 	wl->wl_lock_count++;
   1236 	mutex_exit(&wl->wl_mtx);
   1237 
   1238 #if defined(WAPBL_DEBUG_PRINT)
   1239 	WAPBL_PRINTF(WAPBL_PRINT_TRANSACTION,
   1240 	    ("wapbl_begin thread %d.%d with bufcount=%zu "
   1241 	    "bufbytes=%zu bcount=%zu at %s:%d\n",
   1242 	    curproc->p_pid, curlwp->l_lid, wl->wl_bufcount,
   1243 	    wl->wl_bufbytes, wl->wl_bcount, file, line));
   1244 #endif
   1245 
   1246 	return 0;
   1247 }
   1248 
   1249 void
   1250 wapbl_end(struct wapbl *wl)
   1251 {
   1252 
   1253 #if defined(WAPBL_DEBUG_PRINT)
   1254 	WAPBL_PRINTF(WAPBL_PRINT_TRANSACTION,
   1255 	     ("wapbl_end thread %d.%d with bufcount=%zu "
   1256 	      "bufbytes=%zu bcount=%zu\n",
   1257 	      curproc->p_pid, curlwp->l_lid, wl->wl_bufcount,
   1258 	      wl->wl_bufbytes, wl->wl_bcount));
   1259 #endif
   1260 
   1261 	/*
   1262 	 * XXX this could be handled more gracefully, perhaps place
   1263 	 * only a partial transaction in the log and allow the
   1264 	 * remaining to flush without the protection of the journal.
   1265 	 */
   1266 	KASSERTMSG((wapbl_transaction_len(wl) <=
   1267 		(wl->wl_circ_size - wl->wl_reserved_bytes)),
   1268 	    "wapbl_end: current transaction too big to flush");
   1269 
   1270 	mutex_enter(&wl->wl_mtx);
   1271 	KASSERT(wl->wl_lock_count > 0);
   1272 	wl->wl_lock_count--;
   1273 	mutex_exit(&wl->wl_mtx);
   1274 
   1275 	rw_exit(&wl->wl_rwlock);
   1276 }
   1277 
   1278 void
   1279 wapbl_add_buf(struct wapbl *wl, struct buf * bp)
   1280 {
   1281 
   1282 	KASSERT(bp->b_cflags & BC_BUSY);
   1283 	KASSERT(bp->b_vp);
   1284 
   1285 	wapbl_jlock_assert(wl);
   1286 
   1287 #if 0
   1288 	/*
   1289 	 * XXX this might be an issue for swapfiles.
   1290 	 * see uvm_swap.c:1702
   1291 	 *
   1292 	 * XXX2 why require it then?  leap of semantics?
   1293 	 */
   1294 	KASSERT((bp->b_cflags & BC_NOCACHE) == 0);
   1295 #endif
   1296 
   1297 	mutex_enter(&wl->wl_mtx);
   1298 	if (bp->b_flags & B_LOCKED) {
   1299 		TAILQ_REMOVE(&wl->wl_bufs, bp, b_wapbllist);
   1300 		WAPBL_PRINTF(WAPBL_PRINT_BUFFER2,
   1301 		   ("wapbl_add_buf thread %d.%d re-adding buf %p "
   1302 		    "with %d bytes %d bcount\n",
   1303 		    curproc->p_pid, curlwp->l_lid, bp, bp->b_bufsize,
   1304 		    bp->b_bcount));
   1305 	} else {
   1306 		/* unlocked by dirty buffers shouldn't exist */
   1307 		KASSERT(!(bp->b_oflags & BO_DELWRI));
   1308 		wl->wl_bufbytes += bp->b_bufsize;
   1309 		wl->wl_bcount += bp->b_bcount;
   1310 		wl->wl_bufcount++;
   1311 		WAPBL_PRINTF(WAPBL_PRINT_BUFFER,
   1312 		   ("wapbl_add_buf thread %d.%d adding buf %p "
   1313 		    "with %d bytes %d bcount\n",
   1314 		    curproc->p_pid, curlwp->l_lid, bp, bp->b_bufsize,
   1315 		    bp->b_bcount));
   1316 	}
   1317 	TAILQ_INSERT_TAIL(&wl->wl_bufs, bp, b_wapbllist);
   1318 	mutex_exit(&wl->wl_mtx);
   1319 
   1320 	bp->b_flags |= B_LOCKED;
   1321 }
   1322 
   1323 static void
   1324 wapbl_remove_buf_locked(struct wapbl * wl, struct buf *bp)
   1325 {
   1326 
   1327 	KASSERT(mutex_owned(&wl->wl_mtx));
   1328 	KASSERT(bp->b_cflags & BC_BUSY);
   1329 	wapbl_jlock_assert(wl);
   1330 
   1331 #if 0
   1332 	/*
   1333 	 * XXX this might be an issue for swapfiles.
   1334 	 * see uvm_swap.c:1725
   1335 	 *
   1336 	 * XXXdeux: see above
   1337 	 */
   1338 	KASSERT((bp->b_flags & BC_NOCACHE) == 0);
   1339 #endif
   1340 	KASSERT(bp->b_flags & B_LOCKED);
   1341 
   1342 	WAPBL_PRINTF(WAPBL_PRINT_BUFFER,
   1343 	   ("wapbl_remove_buf thread %d.%d removing buf %p with "
   1344 	    "%d bytes %d bcount\n",
   1345 	    curproc->p_pid, curlwp->l_lid, bp, bp->b_bufsize, bp->b_bcount));
   1346 
   1347 	KASSERT(wl->wl_bufbytes >= bp->b_bufsize);
   1348 	wl->wl_bufbytes -= bp->b_bufsize;
   1349 	KASSERT(wl->wl_bcount >= bp->b_bcount);
   1350 	wl->wl_bcount -= bp->b_bcount;
   1351 	KASSERT(wl->wl_bufcount > 0);
   1352 	wl->wl_bufcount--;
   1353 	KASSERT((wl->wl_bufcount == 0) == (wl->wl_bufbytes == 0));
   1354 	KASSERT((wl->wl_bufcount == 0) == (wl->wl_bcount == 0));
   1355 	TAILQ_REMOVE(&wl->wl_bufs, bp, b_wapbllist);
   1356 
   1357 	bp->b_flags &= ~B_LOCKED;
   1358 }
   1359 
   1360 /* called from brelsel() in vfs_bio among other places */
   1361 void
   1362 wapbl_remove_buf(struct wapbl * wl, struct buf *bp)
   1363 {
   1364 
   1365 	mutex_enter(&wl->wl_mtx);
   1366 	wapbl_remove_buf_locked(wl, bp);
   1367 	mutex_exit(&wl->wl_mtx);
   1368 }
   1369 
   1370 void
   1371 wapbl_resize_buf(struct wapbl *wl, struct buf *bp, long oldsz, long oldcnt)
   1372 {
   1373 
   1374 	KASSERT(bp->b_cflags & BC_BUSY);
   1375 
   1376 	/*
   1377 	 * XXX: why does this depend on B_LOCKED?  otherwise the buf
   1378 	 * is not for a transaction?  if so, why is this called in the
   1379 	 * first place?
   1380 	 */
   1381 	if (bp->b_flags & B_LOCKED) {
   1382 		mutex_enter(&wl->wl_mtx);
   1383 		wl->wl_bufbytes += bp->b_bufsize - oldsz;
   1384 		wl->wl_bcount += bp->b_bcount - oldcnt;
   1385 		mutex_exit(&wl->wl_mtx);
   1386 	}
   1387 }
   1388 
   1389 #endif /* _KERNEL */
   1390 
   1391 /****************************************************************/
   1392 /* Some utility inlines */
   1393 
   1394 /*
   1395  * wapbl_space_used(avail, head, tail)
   1396  *
   1397  *	Number of bytes used in a circular queue of avail total bytes,
   1398  *	from tail to head.
   1399  */
   1400 static inline size_t
   1401 wapbl_space_used(size_t avail, off_t head, off_t tail)
   1402 {
   1403 
   1404 	if (tail == 0) {
   1405 		KASSERT(head == 0);
   1406 		return 0;
   1407 	}
   1408 	return ((head + (avail - 1) - tail) % avail) + 1;
   1409 }
   1410 
   1411 #ifdef _KERNEL
   1412 /*
   1413  * wapbl_advance(size, off, oldoff, delta)
   1414  *
   1415  *	Given a byte offset oldoff into a circular queue of size bytes
   1416  *	starting at off, return a new byte offset oldoff + delta into
   1417  *	the circular queue.
   1418  */
   1419 static inline off_t
   1420 wapbl_advance(size_t size, size_t off, off_t oldoff, size_t delta)
   1421 {
   1422 	off_t newoff;
   1423 
   1424 	/* Define acceptable ranges for inputs. */
   1425 	KASSERT(delta <= (size_t)size);
   1426 	KASSERT((oldoff == 0) || ((size_t)oldoff >= off));
   1427 	KASSERT(oldoff < (off_t)(size + off));
   1428 
   1429 	if ((oldoff == 0) && (delta != 0))
   1430 		newoff = off + delta;
   1431 	else if ((oldoff + delta) < (size + off))
   1432 		newoff = oldoff + delta;
   1433 	else
   1434 		newoff = (oldoff + delta) - size;
   1435 
   1436 	/* Note some interesting axioms */
   1437 	KASSERT((delta != 0) || (newoff == oldoff));
   1438 	KASSERT((delta == 0) || (newoff != 0));
   1439 	KASSERT((delta != (size)) || (newoff == oldoff));
   1440 
   1441 	/* Define acceptable ranges for output. */
   1442 	KASSERT((newoff == 0) || ((size_t)newoff >= off));
   1443 	KASSERT((size_t)newoff < (size + off));
   1444 	return newoff;
   1445 }
   1446 
   1447 /*
   1448  * wapbl_space_free(avail, head, tail)
   1449  *
   1450  *	Number of bytes free in a circular queue of avail total bytes,
   1451  *	in which everything from tail to head is used.
   1452  */
   1453 static inline size_t
   1454 wapbl_space_free(size_t avail, off_t head, off_t tail)
   1455 {
   1456 
   1457 	return avail - wapbl_space_used(avail, head, tail);
   1458 }
   1459 
   1460 /*
   1461  * wapbl_advance_head(size, off, delta, headp, tailp)
   1462  *
   1463  *	In a circular queue of size bytes starting at off, given the
   1464  *	old head and tail offsets *headp and *tailp, store the new head
   1465  *	and tail offsets in *headp and *tailp resulting from adding
   1466  *	delta bytes of data to the head.
   1467  */
   1468 static inline void
   1469 wapbl_advance_head(size_t size, size_t off, size_t delta, off_t *headp,
   1470 		   off_t *tailp)
   1471 {
   1472 	off_t head = *headp;
   1473 	off_t tail = *tailp;
   1474 
   1475 	KASSERT(delta <= wapbl_space_free(size, head, tail));
   1476 	head = wapbl_advance(size, off, head, delta);
   1477 	if ((tail == 0) && (head != 0))
   1478 		tail = off;
   1479 	*headp = head;
   1480 	*tailp = tail;
   1481 }
   1482 
   1483 /*
   1484  * wapbl_advance_tail(size, off, delta, headp, tailp)
   1485  *
   1486  *	In a circular queue of size bytes starting at off, given the
   1487  *	old head and tail offsets *headp and *tailp, store the new head
   1488  *	and tail offsets in *headp and *tailp resulting from removing
   1489  *	delta bytes of data from the tail.
   1490  */
   1491 static inline void
   1492 wapbl_advance_tail(size_t size, size_t off, size_t delta, off_t *headp,
   1493 		   off_t *tailp)
   1494 {
   1495 	off_t head = *headp;
   1496 	off_t tail = *tailp;
   1497 
   1498 	KASSERT(delta <= wapbl_space_used(size, head, tail));
   1499 	tail = wapbl_advance(size, off, tail, delta);
   1500 	if (head == tail) {
   1501 		head = tail = 0;
   1502 	}
   1503 	*headp = head;
   1504 	*tailp = tail;
   1505 }
   1506 
   1507 
   1508 /****************************************************************/
   1509 
   1510 /*
   1511  * wapbl_truncate(wl, minfree)
   1512  *
   1513  *	Wait until at least minfree bytes are available in the log.
   1514  *
   1515  *	If it was necessary to wait for writes to complete,
   1516  *	advance the circular queue tail to reflect the new write
   1517  *	completions and issue a write commit to the log.
   1518  *
   1519  *	=> Caller must hold wl->wl_rwlock writer lock.
   1520  */
   1521 static int
   1522 wapbl_truncate(struct wapbl *wl, size_t minfree)
   1523 {
   1524 	size_t delta;
   1525 	size_t avail;
   1526 	off_t head;
   1527 	off_t tail;
   1528 	int error = 0;
   1529 
   1530 	KASSERT(minfree <= (wl->wl_circ_size - wl->wl_reserved_bytes));
   1531 	KASSERT(rw_write_held(&wl->wl_rwlock));
   1532 
   1533 	mutex_enter(&wl->wl_mtx);
   1534 
   1535 	/*
   1536 	 * First check to see if we have to do a commit
   1537 	 * at all.
   1538 	 */
   1539 	avail = wapbl_space_free(wl->wl_circ_size, wl->wl_head, wl->wl_tail);
   1540 	if (minfree < avail) {
   1541 		mutex_exit(&wl->wl_mtx);
   1542 		return 0;
   1543 	}
   1544 	minfree -= avail;
   1545 	while ((wl->wl_error_count == 0) &&
   1546 	    (wl->wl_reclaimable_bytes < minfree)) {
   1547         	WAPBL_PRINTF(WAPBL_PRINT_TRUNCATE,
   1548                    ("wapbl_truncate: sleeping on %p wl=%p bytes=%zd "
   1549 		    "minfree=%zd\n",
   1550                     &wl->wl_reclaimable_bytes, wl, wl->wl_reclaimable_bytes,
   1551 		    minfree));
   1552 
   1553 		cv_wait(&wl->wl_reclaimable_cv, &wl->wl_mtx);
   1554 	}
   1555 	if (wl->wl_reclaimable_bytes < minfree) {
   1556 		KASSERT(wl->wl_error_count);
   1557 		/* XXX maybe get actual error from buffer instead someday? */
   1558 		error = EIO;
   1559 	}
   1560 	head = wl->wl_head;
   1561 	tail = wl->wl_tail;
   1562 	delta = wl->wl_reclaimable_bytes;
   1563 
   1564 	/* If all of of the entries are flushed, then be sure to keep
   1565 	 * the reserved bytes reserved.  Watch out for discarded transactions,
   1566 	 * which could leave more bytes reserved than are reclaimable.
   1567 	 */
   1568 	if (SIMPLEQ_EMPTY(&wl->wl_entries) &&
   1569 	    (delta >= wl->wl_reserved_bytes)) {
   1570 		delta -= wl->wl_reserved_bytes;
   1571 	}
   1572 	wapbl_advance_tail(wl->wl_circ_size, wl->wl_circ_off, delta, &head,
   1573 			   &tail);
   1574 	KDASSERT(wl->wl_reserved_bytes <=
   1575 		wapbl_space_used(wl->wl_circ_size, head, tail));
   1576 	mutex_exit(&wl->wl_mtx);
   1577 
   1578 	if (error)
   1579 		return error;
   1580 
   1581 	/*
   1582 	 * This is where head, tail and delta are unprotected
   1583 	 * from races against itself or flush.  This is ok since
   1584 	 * we only call this routine from inside flush itself.
   1585 	 *
   1586 	 * XXX: how can it race against itself when accessed only
   1587 	 * from behind the write-locked rwlock?
   1588 	 */
   1589 	error = wapbl_write_commit(wl, head, tail);
   1590 	if (error)
   1591 		return error;
   1592 
   1593 	wl->wl_head = head;
   1594 	wl->wl_tail = tail;
   1595 
   1596 	mutex_enter(&wl->wl_mtx);
   1597 	KASSERT(wl->wl_reclaimable_bytes >= delta);
   1598 	wl->wl_reclaimable_bytes -= delta;
   1599 	mutex_exit(&wl->wl_mtx);
   1600 	WAPBL_PRINTF(WAPBL_PRINT_TRUNCATE,
   1601 	    ("wapbl_truncate thread %d.%d truncating %zu bytes\n",
   1602 	    curproc->p_pid, curlwp->l_lid, delta));
   1603 
   1604 	return 0;
   1605 }
   1606 
   1607 /****************************************************************/
   1608 
   1609 void
   1610 wapbl_biodone(struct buf *bp)
   1611 {
   1612 	struct wapbl_entry *we = bp->b_private;
   1613 	struct wapbl *wl = we->we_wapbl;
   1614 #ifdef WAPBL_DEBUG_BUFBYTES
   1615 	const int bufsize = bp->b_bufsize;
   1616 #endif
   1617 
   1618 	/*
   1619 	 * Handle possible flushing of buffers after log has been
   1620 	 * decomissioned.
   1621 	 */
   1622 	if (!wl) {
   1623 		KASSERT(we->we_bufcount > 0);
   1624 		we->we_bufcount--;
   1625 #ifdef WAPBL_DEBUG_BUFBYTES
   1626 		KASSERT(we->we_unsynced_bufbytes >= bufsize);
   1627 		we->we_unsynced_bufbytes -= bufsize;
   1628 #endif
   1629 
   1630 		if (we->we_bufcount == 0) {
   1631 #ifdef WAPBL_DEBUG_BUFBYTES
   1632 			KASSERT(we->we_unsynced_bufbytes == 0);
   1633 #endif
   1634 			pool_put(&wapbl_entry_pool, we);
   1635 		}
   1636 
   1637 		brelse(bp, 0);
   1638 		return;
   1639 	}
   1640 
   1641 #ifdef ohbother
   1642 	KDASSERT(bp->b_oflags & BO_DONE);
   1643 	KDASSERT(!(bp->b_oflags & BO_DELWRI));
   1644 	KDASSERT(bp->b_flags & B_ASYNC);
   1645 	KDASSERT(bp->b_cflags & BC_BUSY);
   1646 	KDASSERT(!(bp->b_flags & B_LOCKED));
   1647 	KDASSERT(!(bp->b_flags & B_READ));
   1648 	KDASSERT(!(bp->b_cflags & BC_INVAL));
   1649 	KDASSERT(!(bp->b_cflags & BC_NOCACHE));
   1650 #endif
   1651 
   1652 	if (bp->b_error) {
   1653 		/*
   1654 		 * If an error occurs, it would be nice to leave the buffer
   1655 		 * as a delayed write on the LRU queue so that we can retry
   1656 		 * it later. But buffercache(9) can't handle dirty buffer
   1657 		 * reuse, so just mark the log permanently errored out.
   1658 		 */
   1659 		mutex_enter(&wl->wl_mtx);
   1660 		if (wl->wl_error_count == 0) {
   1661 			wl->wl_error_count++;
   1662 			cv_broadcast(&wl->wl_reclaimable_cv);
   1663 		}
   1664 		mutex_exit(&wl->wl_mtx);
   1665 	}
   1666 
   1667 	/*
   1668 	 * Make sure that the buf doesn't retain the media flags, so that
   1669 	 * e.g. wapbl_allow_fuadpo has immediate effect on any following I/O.
   1670 	 * The flags will be set again if needed by another I/O.
   1671 	 */
   1672 	bp->b_flags &= ~B_MEDIA_FLAGS;
   1673 
   1674 	/*
   1675 	 * Release the buffer here. wapbl_flush() may wait for the
   1676 	 * log to become empty and we better unbusy the buffer before
   1677 	 * wapbl_flush() returns.
   1678 	 */
   1679 	brelse(bp, 0);
   1680 
   1681 	mutex_enter(&wl->wl_mtx);
   1682 
   1683 	KASSERT(we->we_bufcount > 0);
   1684 	we->we_bufcount--;
   1685 #ifdef WAPBL_DEBUG_BUFBYTES
   1686 	KASSERT(we->we_unsynced_bufbytes >= bufsize);
   1687 	we->we_unsynced_bufbytes -= bufsize;
   1688 	KASSERT(wl->wl_unsynced_bufbytes >= bufsize);
   1689 	wl->wl_unsynced_bufbytes -= bufsize;
   1690 #endif
   1691 	wl->wl_ev_metawrite.ev_count++;
   1692 
   1693 	/*
   1694 	 * If the current transaction can be reclaimed, start
   1695 	 * at the beginning and reclaim any consecutive reclaimable
   1696 	 * transactions.  If we successfully reclaim anything,
   1697 	 * then wakeup anyone waiting for the reclaim.
   1698 	 */
   1699 	if (we->we_bufcount == 0) {
   1700 		size_t delta = 0;
   1701 		int errcnt = 0;
   1702 #ifdef WAPBL_DEBUG_BUFBYTES
   1703 		KDASSERT(we->we_unsynced_bufbytes == 0);
   1704 #endif
   1705 		/*
   1706 		 * clear any posted error, since the buffer it came from
   1707 		 * has successfully flushed by now
   1708 		 */
   1709 		while ((we = SIMPLEQ_FIRST(&wl->wl_entries)) &&
   1710 		       (we->we_bufcount == 0)) {
   1711 			delta += we->we_reclaimable_bytes;
   1712 			if (we->we_error)
   1713 				errcnt++;
   1714 			SIMPLEQ_REMOVE_HEAD(&wl->wl_entries, we_entries);
   1715 			pool_put(&wapbl_entry_pool, we);
   1716 		}
   1717 
   1718 		if (delta) {
   1719 			wl->wl_reclaimable_bytes += delta;
   1720 			KASSERT(wl->wl_error_count >= errcnt);
   1721 			wl->wl_error_count -= errcnt;
   1722 			cv_broadcast(&wl->wl_reclaimable_cv);
   1723 		}
   1724 	}
   1725 
   1726 	mutex_exit(&wl->wl_mtx);
   1727 }
   1728 
   1729 /*
   1730  * wapbl_flush(wl, wait)
   1731  *
   1732  *	Flush pending block writes, deallocations, and inodes from
   1733  *	the current transaction in memory to the log on disk:
   1734  *
   1735  *	1. Call the file system's wl_flush callback to flush any
   1736  *	   per-file-system pending updates.
   1737  *	2. Wait for enough space in the log for the current transaction.
   1738  *	3. Synchronously write the new log records, advancing the
   1739  *	   circular queue head.
   1740  *	4. Issue the pending block writes asynchronously, now that they
   1741  *	   are recorded in the log and can be replayed after crash.
   1742  *	5. If wait is true, wait for all writes to complete and for the
   1743  *	   log to become empty.
   1744  *
   1745  *	On failure, call the file system's wl_flush_abort callback.
   1746  */
   1747 int
   1748 wapbl_flush(struct wapbl *wl, int waitfor)
   1749 {
   1750 	struct buf *bp;
   1751 	struct wapbl_entry *we;
   1752 	off_t off;
   1753 	off_t head;
   1754 	off_t tail;
   1755 	size_t delta = 0;
   1756 	size_t flushsize;
   1757 	size_t reserved;
   1758 	int error = 0;
   1759 
   1760 	/*
   1761 	 * Do a quick check to see if a full flush can be skipped
   1762 	 * This assumes that the flush callback does not need to be called
   1763 	 * unless there are other outstanding bufs.
   1764 	 */
   1765 	if (!waitfor) {
   1766 		size_t nbufs;
   1767 		mutex_enter(&wl->wl_mtx);	/* XXX need mutex here to
   1768 						   protect the KASSERTS */
   1769 		nbufs = wl->wl_bufcount;
   1770 		KASSERT((wl->wl_bufcount == 0) == (wl->wl_bufbytes == 0));
   1771 		KASSERT((wl->wl_bufcount == 0) == (wl->wl_bcount == 0));
   1772 		mutex_exit(&wl->wl_mtx);
   1773 		if (nbufs == 0)
   1774 			return 0;
   1775 	}
   1776 
   1777 	/*
   1778 	 * XXX we may consider using LK_UPGRADE here
   1779 	 * if we want to call flush from inside a transaction
   1780 	 */
   1781 	rw_enter(&wl->wl_rwlock, RW_WRITER);
   1782 	wl->wl_flush(wl->wl_mount, TAILQ_FIRST(&wl->wl_dealloclist));
   1783 
   1784 	/*
   1785 	 * Now that we are exclusively locked and the file system has
   1786 	 * issued any deferred block writes for this transaction, check
   1787 	 * whether there are any blocks to write to the log.  If not,
   1788 	 * skip waiting for space or writing any log entries.
   1789 	 *
   1790 	 * XXX Shouldn't this also check wl_dealloccnt and
   1791 	 * wl_inohashcnt?  Perhaps wl_dealloccnt doesn't matter if the
   1792 	 * file system didn't produce any blocks as a consequence of
   1793 	 * it, but the same does not seem to be so of wl_inohashcnt.
   1794 	 */
   1795 	if (wl->wl_bufcount == 0) {
   1796 		goto wait_out;
   1797 	}
   1798 
   1799 #if 0
   1800 	WAPBL_PRINTF(WAPBL_PRINT_FLUSH,
   1801 		     ("wapbl_flush thread %d.%d flushing entries with "
   1802 		      "bufcount=%zu bufbytes=%zu\n",
   1803 		      curproc->p_pid, curlwp->l_lid, wl->wl_bufcount,
   1804 		      wl->wl_bufbytes));
   1805 #endif
   1806 
   1807 	/* Calculate amount of space needed to flush */
   1808 	flushsize = wapbl_transaction_len(wl);
   1809 	if (wapbl_verbose_commit) {
   1810 		struct timespec ts;
   1811 		getnanotime(&ts);
   1812 		printf("%s: %lld.%09ld this transaction = %zu bytes\n",
   1813 		    __func__, (long long)ts.tv_sec,
   1814 		    (long)ts.tv_nsec, flushsize);
   1815 	}
   1816 
   1817 	if (flushsize > (wl->wl_circ_size - wl->wl_reserved_bytes)) {
   1818 		/*
   1819 		 * XXX this could be handled more gracefully, perhaps place
   1820 		 * only a partial transaction in the log and allow the
   1821 		 * remaining to flush without the protection of the journal.
   1822 		 */
   1823 		panic("wapbl_flush: current transaction too big to flush");
   1824 	}
   1825 
   1826 	error = wapbl_truncate(wl, flushsize);
   1827 	if (error)
   1828 		goto out;
   1829 
   1830 	off = wl->wl_head;
   1831 	KASSERT((off == 0) || (off >= wl->wl_circ_off));
   1832 	KASSERT((off == 0) || (off < wl->wl_circ_off + wl->wl_circ_size));
   1833 	error = wapbl_write_blocks(wl, &off);
   1834 	if (error)
   1835 		goto out;
   1836 	error = wapbl_write_revocations(wl, &off);
   1837 	if (error)
   1838 		goto out;
   1839 	error = wapbl_write_inodes(wl, &off);
   1840 	if (error)
   1841 		goto out;
   1842 
   1843 	reserved = 0;
   1844 	if (wl->wl_inohashcnt)
   1845 		reserved = wapbl_transaction_inodes_len(wl);
   1846 
   1847 	head = wl->wl_head;
   1848 	tail = wl->wl_tail;
   1849 
   1850 	wapbl_advance_head(wl->wl_circ_size, wl->wl_circ_off, flushsize,
   1851 	    &head, &tail);
   1852 
   1853 	KASSERTMSG(head == off,
   1854 	    "lost head! head=%"PRIdMAX" tail=%" PRIdMAX
   1855 	    " off=%"PRIdMAX" flush=%zu",
   1856 	    (intmax_t)head, (intmax_t)tail, (intmax_t)off,
   1857 	    flushsize);
   1858 
   1859 	/* Opportunistically move the tail forward if we can */
   1860 	mutex_enter(&wl->wl_mtx);
   1861 	delta = wl->wl_reclaimable_bytes;
   1862 	mutex_exit(&wl->wl_mtx);
   1863 	wapbl_advance_tail(wl->wl_circ_size, wl->wl_circ_off, delta,
   1864 	    &head, &tail);
   1865 
   1866 	error = wapbl_write_commit(wl, head, tail);
   1867 	if (error)
   1868 		goto out;
   1869 
   1870 	we = pool_get(&wapbl_entry_pool, PR_WAITOK);
   1871 
   1872 #ifdef WAPBL_DEBUG_BUFBYTES
   1873 	WAPBL_PRINTF(WAPBL_PRINT_FLUSH,
   1874 		("wapbl_flush: thread %d.%d head+=%zu tail+=%zu used=%zu"
   1875 		 " unsynced=%zu"
   1876 		 "\n\tbufcount=%zu bufbytes=%zu bcount=%zu deallocs=%d "
   1877 		 "inodes=%d\n",
   1878 		 curproc->p_pid, curlwp->l_lid, flushsize, delta,
   1879 		 wapbl_space_used(wl->wl_circ_size, head, tail),
   1880 		 wl->wl_unsynced_bufbytes, wl->wl_bufcount,
   1881 		 wl->wl_bufbytes, wl->wl_bcount, wl->wl_dealloccnt,
   1882 		 wl->wl_inohashcnt));
   1883 #else
   1884 	WAPBL_PRINTF(WAPBL_PRINT_FLUSH,
   1885 		("wapbl_flush: thread %d.%d head+=%zu tail+=%zu used=%zu"
   1886 		 "\n\tbufcount=%zu bufbytes=%zu bcount=%zu deallocs=%d "
   1887 		 "inodes=%d\n",
   1888 		 curproc->p_pid, curlwp->l_lid, flushsize, delta,
   1889 		 wapbl_space_used(wl->wl_circ_size, head, tail),
   1890 		 wl->wl_bufcount, wl->wl_bufbytes, wl->wl_bcount,
   1891 		 wl->wl_dealloccnt, wl->wl_inohashcnt));
   1892 #endif
   1893 
   1894 
   1895 	mutex_enter(&bufcache_lock);
   1896 	mutex_enter(&wl->wl_mtx);
   1897 
   1898 	wl->wl_reserved_bytes = reserved;
   1899 	wl->wl_head = head;
   1900 	wl->wl_tail = tail;
   1901 	KASSERT(wl->wl_reclaimable_bytes >= delta);
   1902 	wl->wl_reclaimable_bytes -= delta;
   1903 	KDASSERT(wl->wl_dealloccnt == 0);
   1904 #ifdef WAPBL_DEBUG_BUFBYTES
   1905 	wl->wl_unsynced_bufbytes += wl->wl_bufbytes;
   1906 #endif
   1907 
   1908 	we->we_wapbl = wl;
   1909 	we->we_bufcount = wl->wl_bufcount;
   1910 #ifdef WAPBL_DEBUG_BUFBYTES
   1911 	we->we_unsynced_bufbytes = wl->wl_bufbytes;
   1912 #endif
   1913 	we->we_reclaimable_bytes = flushsize;
   1914 	we->we_error = 0;
   1915 	SIMPLEQ_INSERT_TAIL(&wl->wl_entries, we, we_entries);
   1916 
   1917 	/*
   1918 	 * This flushes bufs in order than they were queued, so the LRU
   1919 	 * order is preserved.
   1920 	 */
   1921 	while ((bp = TAILQ_FIRST(&wl->wl_bufs)) != NULL) {
   1922 		if (bbusy(bp, 0, 0, &wl->wl_mtx)) {
   1923 			continue;
   1924 		}
   1925 		bp->b_iodone = wapbl_biodone;
   1926 		bp->b_private = we;
   1927 
   1928 		/* make sure the block is saved sync when FUA in use */
   1929 		bp->b_flags |= WAPBL_MFLAGS(wl);
   1930 
   1931 		bremfree(bp);
   1932 		wapbl_remove_buf_locked(wl, bp);
   1933 		mutex_exit(&wl->wl_mtx);
   1934 		mutex_exit(&bufcache_lock);
   1935 		bawrite(bp);
   1936 		mutex_enter(&bufcache_lock);
   1937 		mutex_enter(&wl->wl_mtx);
   1938 	}
   1939 	mutex_exit(&wl->wl_mtx);
   1940 	mutex_exit(&bufcache_lock);
   1941 
   1942 #if 0
   1943 	WAPBL_PRINTF(WAPBL_PRINT_FLUSH,
   1944 		     ("wapbl_flush thread %d.%d done flushing entries...\n",
   1945 		     curproc->p_pid, curlwp->l_lid));
   1946 #endif
   1947 
   1948  wait_out:
   1949 
   1950 	/*
   1951 	 * If the waitfor flag is set, don't return until everything is
   1952 	 * fully flushed and the on disk log is empty.
   1953 	 */
   1954 	if (waitfor) {
   1955 		error = wapbl_truncate(wl, wl->wl_circ_size -
   1956 			wl->wl_reserved_bytes);
   1957 	}
   1958 
   1959  out:
   1960 	if (error) {
   1961 		wl->wl_flush_abort(wl->wl_mount,
   1962 		    TAILQ_FIRST(&wl->wl_dealloclist));
   1963 	}
   1964 
   1965 #ifdef WAPBL_DEBUG_PRINT
   1966 	if (error) {
   1967 		pid_t pid = -1;
   1968 		lwpid_t lid = -1;
   1969 		if (curproc)
   1970 			pid = curproc->p_pid;
   1971 		if (curlwp)
   1972 			lid = curlwp->l_lid;
   1973 		mutex_enter(&wl->wl_mtx);
   1974 #ifdef WAPBL_DEBUG_BUFBYTES
   1975 		WAPBL_PRINTF(WAPBL_PRINT_ERROR,
   1976 		    ("wapbl_flush: thread %d.%d aborted flush: "
   1977 		    "error = %d\n"
   1978 		    "\tbufcount=%zu bufbytes=%zu bcount=%zu "
   1979 		    "deallocs=%d inodes=%d\n"
   1980 		    "\terrcnt = %d, reclaimable=%zu reserved=%zu "
   1981 		    "unsynced=%zu\n",
   1982 		    pid, lid, error, wl->wl_bufcount,
   1983 		    wl->wl_bufbytes, wl->wl_bcount,
   1984 		    wl->wl_dealloccnt, wl->wl_inohashcnt,
   1985 		    wl->wl_error_count, wl->wl_reclaimable_bytes,
   1986 		    wl->wl_reserved_bytes, wl->wl_unsynced_bufbytes));
   1987 		SIMPLEQ_FOREACH(we, &wl->wl_entries, we_entries) {
   1988 			WAPBL_PRINTF(WAPBL_PRINT_ERROR,
   1989 			    ("\tentry: bufcount = %zu, reclaimable = %zu, "
   1990 			     "error = %d, unsynced = %zu\n",
   1991 			     we->we_bufcount, we->we_reclaimable_bytes,
   1992 			     we->we_error, we->we_unsynced_bufbytes));
   1993 		}
   1994 #else
   1995 		WAPBL_PRINTF(WAPBL_PRINT_ERROR,
   1996 		    ("wapbl_flush: thread %d.%d aborted flush: "
   1997 		     "error = %d\n"
   1998 		     "\tbufcount=%zu bufbytes=%zu bcount=%zu "
   1999 		     "deallocs=%d inodes=%d\n"
   2000 		     "\terrcnt = %d, reclaimable=%zu reserved=%zu\n",
   2001 		     pid, lid, error, wl->wl_bufcount,
   2002 		     wl->wl_bufbytes, wl->wl_bcount,
   2003 		     wl->wl_dealloccnt, wl->wl_inohashcnt,
   2004 		     wl->wl_error_count, wl->wl_reclaimable_bytes,
   2005 		     wl->wl_reserved_bytes));
   2006 		SIMPLEQ_FOREACH(we, &wl->wl_entries, we_entries) {
   2007 			WAPBL_PRINTF(WAPBL_PRINT_ERROR,
   2008 			    ("\tentry: bufcount = %zu, reclaimable = %zu, "
   2009 			     "error = %d\n", we->we_bufcount,
   2010 			     we->we_reclaimable_bytes, we->we_error));
   2011 		}
   2012 #endif
   2013 		mutex_exit(&wl->wl_mtx);
   2014 	}
   2015 #endif
   2016 
   2017 	rw_exit(&wl->wl_rwlock);
   2018 	return error;
   2019 }
   2020 
   2021 /****************************************************************/
   2022 
   2023 void
   2024 wapbl_jlock_assert(struct wapbl *wl)
   2025 {
   2026 
   2027 	KASSERT(rw_lock_held(&wl->wl_rwlock));
   2028 }
   2029 
   2030 void
   2031 wapbl_junlock_assert(struct wapbl *wl)
   2032 {
   2033 
   2034 	KASSERT(!rw_write_held(&wl->wl_rwlock));
   2035 }
   2036 
   2037 /****************************************************************/
   2038 
   2039 /* locks missing */
   2040 void
   2041 wapbl_print(struct wapbl *wl,
   2042 		int full,
   2043 		void (*pr)(const char *, ...))
   2044 {
   2045 	struct buf *bp;
   2046 	struct wapbl_entry *we;
   2047 	(*pr)("wapbl %p", wl);
   2048 	(*pr)("\nlogvp = %p, devvp = %p, logpbn = %"PRId64"\n",
   2049 	      wl->wl_logvp, wl->wl_devvp, wl->wl_logpbn);
   2050 	(*pr)("circ = %zu, header = %zu, head = %"PRIdMAX" tail = %"PRIdMAX"\n",
   2051 	      wl->wl_circ_size, wl->wl_circ_off,
   2052 	      (intmax_t)wl->wl_head, (intmax_t)wl->wl_tail);
   2053 	(*pr)("fs_dev_bshift = %d, log_dev_bshift = %d\n",
   2054 	      wl->wl_log_dev_bshift, wl->wl_fs_dev_bshift);
   2055 #ifdef WAPBL_DEBUG_BUFBYTES
   2056 	(*pr)("bufcount = %zu, bufbytes = %zu bcount = %zu reclaimable = %zu "
   2057 	      "reserved = %zu errcnt = %d unsynced = %zu\n",
   2058 	      wl->wl_bufcount, wl->wl_bufbytes, wl->wl_bcount,
   2059 	      wl->wl_reclaimable_bytes, wl->wl_reserved_bytes,
   2060 				wl->wl_error_count, wl->wl_unsynced_bufbytes);
   2061 #else
   2062 	(*pr)("bufcount = %zu, bufbytes = %zu bcount = %zu reclaimable = %zu "
   2063 	      "reserved = %zu errcnt = %d\n", wl->wl_bufcount, wl->wl_bufbytes,
   2064 	      wl->wl_bcount, wl->wl_reclaimable_bytes, wl->wl_reserved_bytes,
   2065 				wl->wl_error_count);
   2066 #endif
   2067 	(*pr)("\tdealloccnt = %d, dealloclim = %d\n",
   2068 	      wl->wl_dealloccnt, wl->wl_dealloclim);
   2069 	(*pr)("\tinohashcnt = %d, inohashmask = 0x%08x\n",
   2070 	      wl->wl_inohashcnt, wl->wl_inohashmask);
   2071 	(*pr)("entries:\n");
   2072 	SIMPLEQ_FOREACH(we, &wl->wl_entries, we_entries) {
   2073 #ifdef WAPBL_DEBUG_BUFBYTES
   2074 		(*pr)("\tbufcount = %zu, reclaimable = %zu, error = %d, "
   2075 		      "unsynced = %zu\n",
   2076 		      we->we_bufcount, we->we_reclaimable_bytes,
   2077 		      we->we_error, we->we_unsynced_bufbytes);
   2078 #else
   2079 		(*pr)("\tbufcount = %zu, reclaimable = %zu, error = %d\n",
   2080 		      we->we_bufcount, we->we_reclaimable_bytes, we->we_error);
   2081 #endif
   2082 	}
   2083 	if (full) {
   2084 		int cnt = 0;
   2085 		(*pr)("bufs =");
   2086 		TAILQ_FOREACH(bp, &wl->wl_bufs, b_wapbllist) {
   2087 			if (!TAILQ_NEXT(bp, b_wapbllist)) {
   2088 				(*pr)(" %p", bp);
   2089 			} else if ((++cnt % 6) == 0) {
   2090 				(*pr)(" %p,\n\t", bp);
   2091 			} else {
   2092 				(*pr)(" %p,", bp);
   2093 			}
   2094 		}
   2095 		(*pr)("\n");
   2096 
   2097 		(*pr)("dealloced blks = ");
   2098 		{
   2099 			struct wapbl_dealloc *wd;
   2100 			cnt = 0;
   2101 			TAILQ_FOREACH(wd, &wl->wl_dealloclist, wd_entries) {
   2102 				(*pr)(" %"PRId64":%d,",
   2103 				      wd->wd_blkno,
   2104 				      wd->wd_len);
   2105 				if ((++cnt % 4) == 0) {
   2106 					(*pr)("\n\t");
   2107 				}
   2108 			}
   2109 		}
   2110 		(*pr)("\n");
   2111 
   2112 		(*pr)("registered inodes = ");
   2113 		{
   2114 			int i;
   2115 			cnt = 0;
   2116 			for (i = 0; i <= wl->wl_inohashmask; i++) {
   2117 				struct wapbl_ino_head *wih;
   2118 				struct wapbl_ino *wi;
   2119 
   2120 				wih = &wl->wl_inohash[i];
   2121 				LIST_FOREACH(wi, wih, wi_hash) {
   2122 					if (wi->wi_ino == 0)
   2123 						continue;
   2124 					(*pr)(" %"PRIu64"/0%06"PRIo32",",
   2125 					    wi->wi_ino, wi->wi_mode);
   2126 					if ((++cnt % 4) == 0) {
   2127 						(*pr)("\n\t");
   2128 					}
   2129 				}
   2130 			}
   2131 			(*pr)("\n");
   2132 		}
   2133 
   2134 		(*pr)("iobufs free =");
   2135 		TAILQ_FOREACH(bp, &wl->wl_iobufs, b_wapbllist) {
   2136 			if (!TAILQ_NEXT(bp, b_wapbllist)) {
   2137 				(*pr)(" %p", bp);
   2138 			} else if ((++cnt % 6) == 0) {
   2139 				(*pr)(" %p,\n\t", bp);
   2140 			} else {
   2141 				(*pr)(" %p,", bp);
   2142 			}
   2143 		}
   2144 		(*pr)("\n");
   2145 
   2146 		(*pr)("iobufs busy =");
   2147 		TAILQ_FOREACH(bp, &wl->wl_iobufs_busy, b_wapbllist) {
   2148 			if (!TAILQ_NEXT(bp, b_wapbllist)) {
   2149 				(*pr)(" %p", bp);
   2150 			} else if ((++cnt % 6) == 0) {
   2151 				(*pr)(" %p,\n\t", bp);
   2152 			} else {
   2153 				(*pr)(" %p,", bp);
   2154 			}
   2155 		}
   2156 		(*pr)("\n");
   2157 	}
   2158 }
   2159 
   2160 #if defined(WAPBL_DEBUG) || defined(DDB)
   2161 void
   2162 wapbl_dump(struct wapbl *wl)
   2163 {
   2164 #if defined(WAPBL_DEBUG)
   2165 	if (!wl)
   2166 		wl = wapbl_debug_wl;
   2167 #endif
   2168 	if (!wl)
   2169 		return;
   2170 	wapbl_print(wl, 1, printf);
   2171 }
   2172 #endif
   2173 
   2174 /****************************************************************/
   2175 
   2176 int
   2177 wapbl_register_deallocation(struct wapbl *wl, daddr_t blk, int len, bool force,
   2178     void **cookiep)
   2179 {
   2180 	struct wapbl_dealloc *wd;
   2181 	int error = 0;
   2182 
   2183 	wapbl_jlock_assert(wl);
   2184 
   2185 	mutex_enter(&wl->wl_mtx);
   2186 
   2187 	if (__predict_false(wl->wl_dealloccnt >= wl->wl_dealloclim)) {
   2188 		if (!force) {
   2189 			error = EAGAIN;
   2190 			goto out;
   2191 		}
   2192 
   2193 		/*
   2194 		 * Forced registration can only be used when:
   2195 		 * 1) the caller can't cope with failure
   2196 		 * 2) the path can be triggered only bounded, small
   2197 		 *    times per transaction
   2198 		 * If this is not fullfilled, and the path would be triggered
   2199 		 * many times, this could overflow maximum transaction size
   2200 		 * and panic later.
   2201 		 */
   2202 		printf("%s: forced dealloc registration over limit: %d >= %d\n",
   2203 			wl->wl_mount->mnt_stat.f_mntonname,
   2204 			wl->wl_dealloccnt, wl->wl_dealloclim);
   2205 	}
   2206 
   2207 	wl->wl_dealloccnt++;
   2208 	mutex_exit(&wl->wl_mtx);
   2209 
   2210 	wd = pool_get(&wapbl_dealloc_pool, PR_WAITOK);
   2211 	wd->wd_blkno = blk;
   2212 	wd->wd_len = len;
   2213 
   2214 	mutex_enter(&wl->wl_mtx);
   2215 	TAILQ_INSERT_TAIL(&wl->wl_dealloclist, wd, wd_entries);
   2216 
   2217 	if (cookiep)
   2218 		*cookiep = wd;
   2219 
   2220  out:
   2221 	mutex_exit(&wl->wl_mtx);
   2222 
   2223 	WAPBL_PRINTF(WAPBL_PRINT_ALLOC,
   2224 	    ("wapbl_register_deallocation: blk=%"PRId64" len=%d error=%d\n",
   2225 	    blk, len, error));
   2226 
   2227 	return error;
   2228 }
   2229 
   2230 static void
   2231 wapbl_deallocation_free(struct wapbl *wl, struct wapbl_dealloc *wd,
   2232 	bool locked)
   2233 {
   2234 	KASSERT(!locked
   2235 	    || rw_lock_held(&wl->wl_rwlock) || mutex_owned(&wl->wl_mtx));
   2236 
   2237 	if (!locked)
   2238 		mutex_enter(&wl->wl_mtx);
   2239 
   2240 	TAILQ_REMOVE(&wl->wl_dealloclist, wd, wd_entries);
   2241 	wl->wl_dealloccnt--;
   2242 
   2243 	if (!locked)
   2244 		mutex_exit(&wl->wl_mtx);
   2245 
   2246 	pool_put(&wapbl_dealloc_pool, wd);
   2247 }
   2248 
   2249 void
   2250 wapbl_unregister_deallocation(struct wapbl *wl, void *cookie)
   2251 {
   2252 	KASSERT(cookie != NULL);
   2253 	wapbl_deallocation_free(wl, cookie, false);
   2254 }
   2255 
   2256 /****************************************************************/
   2257 
   2258 static void
   2259 wapbl_inodetrk_init(struct wapbl *wl, u_int size)
   2260 {
   2261 
   2262 	wl->wl_inohash = hashinit(size, HASH_LIST, true, &wl->wl_inohashmask);
   2263 	if (atomic_inc_uint_nv(&wapbl_ino_pool_refcount) == 1) {
   2264 		pool_init(&wapbl_ino_pool, sizeof(struct wapbl_ino), 0, 0, 0,
   2265 		    "wapblinopl", &pool_allocator_nointr, IPL_NONE);
   2266 	}
   2267 }
   2268 
   2269 static void
   2270 wapbl_inodetrk_free(struct wapbl *wl)
   2271 {
   2272 
   2273 	/* XXX this KASSERT needs locking/mutex analysis */
   2274 	KASSERT(wl->wl_inohashcnt == 0);
   2275 	hashdone(wl->wl_inohash, HASH_LIST, wl->wl_inohashmask);
   2276 	if (atomic_dec_uint_nv(&wapbl_ino_pool_refcount) == 0) {
   2277 		pool_destroy(&wapbl_ino_pool);
   2278 	}
   2279 }
   2280 
   2281 static struct wapbl_ino *
   2282 wapbl_inodetrk_get(struct wapbl *wl, ino_t ino)
   2283 {
   2284 	struct wapbl_ino_head *wih;
   2285 	struct wapbl_ino *wi;
   2286 
   2287 	KASSERT(mutex_owned(&wl->wl_mtx));
   2288 
   2289 	wih = &wl->wl_inohash[ino & wl->wl_inohashmask];
   2290 	LIST_FOREACH(wi, wih, wi_hash) {
   2291 		if (ino == wi->wi_ino)
   2292 			return wi;
   2293 	}
   2294 	return 0;
   2295 }
   2296 
   2297 void
   2298 wapbl_register_inode(struct wapbl *wl, ino_t ino, mode_t mode)
   2299 {
   2300 	struct wapbl_ino_head *wih;
   2301 	struct wapbl_ino *wi;
   2302 
   2303 	wi = pool_get(&wapbl_ino_pool, PR_WAITOK);
   2304 
   2305 	mutex_enter(&wl->wl_mtx);
   2306 	if (wapbl_inodetrk_get(wl, ino) == NULL) {
   2307 		wi->wi_ino = ino;
   2308 		wi->wi_mode = mode;
   2309 		wih = &wl->wl_inohash[ino & wl->wl_inohashmask];
   2310 		LIST_INSERT_HEAD(wih, wi, wi_hash);
   2311 		wl->wl_inohashcnt++;
   2312 		WAPBL_PRINTF(WAPBL_PRINT_INODE,
   2313 		    ("wapbl_register_inode: ino=%"PRId64"\n", ino));
   2314 		mutex_exit(&wl->wl_mtx);
   2315 	} else {
   2316 		mutex_exit(&wl->wl_mtx);
   2317 		pool_put(&wapbl_ino_pool, wi);
   2318 	}
   2319 }
   2320 
   2321 void
   2322 wapbl_unregister_inode(struct wapbl *wl, ino_t ino, mode_t mode)
   2323 {
   2324 	struct wapbl_ino *wi;
   2325 
   2326 	mutex_enter(&wl->wl_mtx);
   2327 	wi = wapbl_inodetrk_get(wl, ino);
   2328 	if (wi) {
   2329 		WAPBL_PRINTF(WAPBL_PRINT_INODE,
   2330 		    ("wapbl_unregister_inode: ino=%"PRId64"\n", ino));
   2331 		KASSERT(wl->wl_inohashcnt > 0);
   2332 		wl->wl_inohashcnt--;
   2333 		LIST_REMOVE(wi, wi_hash);
   2334 		mutex_exit(&wl->wl_mtx);
   2335 
   2336 		pool_put(&wapbl_ino_pool, wi);
   2337 	} else {
   2338 		mutex_exit(&wl->wl_mtx);
   2339 	}
   2340 }
   2341 
   2342 /****************************************************************/
   2343 
   2344 /*
   2345  * wapbl_transaction_inodes_len(wl)
   2346  *
   2347  *	Calculate the number of bytes required for inode registration
   2348  *	log records in wl.
   2349  */
   2350 static inline size_t
   2351 wapbl_transaction_inodes_len(struct wapbl *wl)
   2352 {
   2353 	int blocklen = 1<<wl->wl_log_dev_bshift;
   2354 	int iph;
   2355 
   2356 	/* Calculate number of inodes described in a inodelist header */
   2357 	iph = (blocklen - offsetof(struct wapbl_wc_inodelist, wc_inodes)) /
   2358 	    sizeof(((struct wapbl_wc_inodelist *)0)->wc_inodes[0]);
   2359 
   2360 	KASSERT(iph > 0);
   2361 
   2362 	return MAX(1, howmany(wl->wl_inohashcnt, iph)) * blocklen;
   2363 }
   2364 
   2365 
   2366 /*
   2367  * wapbl_transaction_len(wl)
   2368  *
   2369  *	Calculate number of bytes required for all log records in wl.
   2370  */
   2371 static size_t
   2372 wapbl_transaction_len(struct wapbl *wl)
   2373 {
   2374 	int blocklen = 1<<wl->wl_log_dev_bshift;
   2375 	size_t len;
   2376 
   2377 	/* Calculate number of blocks described in a blocklist header */
   2378 	len = wl->wl_bcount;
   2379 	len += howmany(wl->wl_bufcount, wl->wl_brperjblock) * blocklen;
   2380 	len += howmany(wl->wl_dealloccnt, wl->wl_brperjblock) * blocklen;
   2381 	len += wapbl_transaction_inodes_len(wl);
   2382 
   2383 	return len;
   2384 }
   2385 
   2386 /*
   2387  * wapbl_cache_sync(wl, msg)
   2388  *
   2389  *	Issue DIOCCACHESYNC to wl->wl_devvp.
   2390  *
   2391  *	If sysctl(vfs.wapbl.verbose_commit) >= 2, print a message
   2392  *	including msg about the duration of the cache sync.
   2393  */
   2394 static int
   2395 wapbl_cache_sync(struct wapbl *wl, const char *msg)
   2396 {
   2397 	const bool verbose = wapbl_verbose_commit >= 2;
   2398 	struct bintime start_time;
   2399 	int force = 1;
   2400 	int error;
   2401 
   2402 	/* Skip full cache sync if disabled, or when using FUA */
   2403 	if (!wapbl_flush_disk_cache || WAPBL_USE_FUA(wl)) {
   2404 		return 0;
   2405 	}
   2406 	if (verbose) {
   2407 		bintime(&start_time);
   2408 	}
   2409 	error = VOP_IOCTL(wl->wl_devvp, DIOCCACHESYNC, &force,
   2410 	    FWRITE, FSCRED);
   2411 	if (error) {
   2412 		WAPBL_PRINTF(WAPBL_PRINT_ERROR,
   2413 		    ("wapbl_cache_sync: DIOCCACHESYNC on dev 0x%jx "
   2414 		    "returned %d\n", (uintmax_t)wl->wl_devvp->v_rdev, error));
   2415 	}
   2416 	if (verbose) {
   2417 		struct bintime d;
   2418 		struct timespec ts;
   2419 
   2420 		bintime(&d);
   2421 		bintime_sub(&d, &start_time);
   2422 		bintime2timespec(&d, &ts);
   2423 		printf("wapbl_cache_sync: %s: dev 0x%jx %ju.%09lu\n",
   2424 		    msg, (uintmax_t)wl->wl_devvp->v_rdev,
   2425 		    (uintmax_t)ts.tv_sec, ts.tv_nsec);
   2426 	}
   2427 
   2428 	wl->wl_ev_cacheflush.ev_count++;
   2429 
   2430 	return error;
   2431 }
   2432 
   2433 /*
   2434  * wapbl_write_commit(wl, head, tail)
   2435  *
   2436  *	Issue a disk cache sync to wait for all pending writes to the
   2437  *	log to complete, and then synchronously commit the current
   2438  *	circular queue head and tail to the log, in the next of two
   2439  *	locations for commit headers on disk.
   2440  *
   2441  *	Increment the generation number.  If the generation number
   2442  *	rolls over to zero, then a subsequent commit would appear to
   2443  *	have an older generation than this one -- in that case, issue a
   2444  *	duplicate commit to avoid this.
   2445  *
   2446  *	=> Caller must have exclusive access to wl, either by holding
   2447  *	wl->wl_rwlock for writer or by being wapbl_start before anyone
   2448  *	else has seen wl.
   2449  */
   2450 static int
   2451 wapbl_write_commit(struct wapbl *wl, off_t head, off_t tail)
   2452 {
   2453 	struct wapbl_wc_header *wc = wl->wl_wc_header;
   2454 	struct timespec ts;
   2455 	int error;
   2456 	daddr_t pbn;
   2457 
   2458 	error = wapbl_buffered_flush(wl, true);
   2459 	if (error)
   2460 		return error;
   2461 	/*
   2462 	 * flush disk cache to ensure that blocks we've written are actually
   2463 	 * written to the stable storage before the commit header.
   2464 	 *
   2465 	 * XXX Calc checksum here, instead we do this for now
   2466 	 */
   2467 	wapbl_cache_sync(wl, "1");
   2468 
   2469 	wc->wc_head = head;
   2470 	wc->wc_tail = tail;
   2471 	wc->wc_checksum = 0;
   2472 	wc->wc_version = 1;
   2473 	getnanotime(&ts);
   2474 	wc->wc_time = ts.tv_sec;
   2475 	wc->wc_timensec = ts.tv_nsec;
   2476 
   2477 	WAPBL_PRINTF(WAPBL_PRINT_WRITE,
   2478 	    ("wapbl_write_commit: head = %"PRIdMAX "tail = %"PRIdMAX"\n",
   2479 	    (intmax_t)head, (intmax_t)tail));
   2480 
   2481 	/*
   2482 	 * write the commit header.
   2483 	 *
   2484 	 * XXX if generation will rollover, then first zero
   2485 	 * over second commit header before trying to write both headers.
   2486 	 */
   2487 
   2488 	pbn = wl->wl_logpbn + (wc->wc_generation % 2);
   2489 #ifdef _KERNEL
   2490 	pbn = btodb(pbn << wc->wc_log_dev_bshift);
   2491 #endif
   2492 	error = wapbl_buffered_write(wc, wc->wc_len, wl, pbn);
   2493 	if (error)
   2494 		return error;
   2495 	error = wapbl_buffered_flush(wl, true);
   2496 	if (error)
   2497 		return error;
   2498 
   2499 	/*
   2500 	 * flush disk cache to ensure that the commit header is actually
   2501 	 * written before meta data blocks.
   2502 	 */
   2503 	wapbl_cache_sync(wl, "2");
   2504 
   2505 	/*
   2506 	 * If the generation number was zero, write it out a second time.
   2507 	 * This handles initialization and generation number rollover
   2508 	 */
   2509 	if (wc->wc_generation++ == 0) {
   2510 		error = wapbl_write_commit(wl, head, tail);
   2511 		/*
   2512 		 * This panic should be able to be removed if we do the
   2513 		 * zero'ing mentioned above, and we are certain to roll
   2514 		 * back generation number on failure.
   2515 		 */
   2516 		if (error)
   2517 			panic("wapbl_write_commit: error writing duplicate "
   2518 			      "log header: %d", error);
   2519 	}
   2520 
   2521 	wl->wl_ev_commit.ev_count++;
   2522 
   2523 	return 0;
   2524 }
   2525 
   2526 /*
   2527  * wapbl_write_blocks(wl, offp)
   2528  *
   2529  *	Write all pending physical blocks in the current transaction
   2530  *	from wapbl_add_buf to the log on disk, adding to the circular
   2531  *	queue head at byte offset *offp, and returning the new head's
   2532  *	byte offset in *offp.
   2533  */
   2534 static int
   2535 wapbl_write_blocks(struct wapbl *wl, off_t *offp)
   2536 {
   2537 	struct wapbl_wc_blocklist *wc =
   2538 	    (struct wapbl_wc_blocklist *)wl->wl_wc_scratch;
   2539 	int blocklen = 1<<wl->wl_log_dev_bshift;
   2540 	struct buf *bp;
   2541 	off_t off = *offp;
   2542 	int error;
   2543 	size_t padding;
   2544 
   2545 	KASSERT(rw_write_held(&wl->wl_rwlock));
   2546 
   2547 	bp = TAILQ_FIRST(&wl->wl_bufs);
   2548 
   2549 	while (bp) {
   2550 		int cnt;
   2551 		struct buf *obp = bp;
   2552 
   2553 		KASSERT(bp->b_flags & B_LOCKED);
   2554 
   2555 		wc->wc_type = WAPBL_WC_BLOCKS;
   2556 		wc->wc_len = blocklen;
   2557 		wc->wc_blkcount = 0;
   2558 		while (bp && (wc->wc_blkcount < wl->wl_brperjblock)) {
   2559 			/*
   2560 			 * Make sure all the physical block numbers are up to
   2561 			 * date.  If this is not always true on a given
   2562 			 * filesystem, then VOP_BMAP must be called.  We
   2563 			 * could call VOP_BMAP here, or else in the filesystem
   2564 			 * specific flush callback, although neither of those
   2565 			 * solutions allow us to take the vnode lock.  If a
   2566 			 * filesystem requires that we must take the vnode lock
   2567 			 * to call VOP_BMAP, then we can probably do it in
   2568 			 * bwrite when the vnode lock should already be held
   2569 			 * by the invoking code.
   2570 			 */
   2571 			KASSERT((bp->b_vp->v_type == VBLK) ||
   2572 				 (bp->b_blkno != bp->b_lblkno));
   2573 			KASSERT(bp->b_blkno > 0);
   2574 
   2575 			wc->wc_blocks[wc->wc_blkcount].wc_daddr = bp->b_blkno;
   2576 			wc->wc_blocks[wc->wc_blkcount].wc_dlen = bp->b_bcount;
   2577 			wc->wc_len += bp->b_bcount;
   2578 			wc->wc_blkcount++;
   2579 			bp = TAILQ_NEXT(bp, b_wapbllist);
   2580 		}
   2581 		if (wc->wc_len % blocklen != 0) {
   2582 			padding = blocklen - wc->wc_len % blocklen;
   2583 			wc->wc_len += padding;
   2584 		} else {
   2585 			padding = 0;
   2586 		}
   2587 
   2588 		WAPBL_PRINTF(WAPBL_PRINT_WRITE,
   2589 		    ("wapbl_write_blocks: len = %u (padding %zu) off = %"PRIdMAX"\n",
   2590 		    wc->wc_len, padding, (intmax_t)off));
   2591 
   2592 		error = wapbl_circ_write(wl, wc, blocklen, &off);
   2593 		if (error)
   2594 			return error;
   2595 		bp = obp;
   2596 		cnt = 0;
   2597 		while (bp && (cnt++ < wl->wl_brperjblock)) {
   2598 			error = wapbl_circ_write(wl, bp->b_data,
   2599 			    bp->b_bcount, &off);
   2600 			if (error)
   2601 				return error;
   2602 			bp = TAILQ_NEXT(bp, b_wapbllist);
   2603 		}
   2604 		if (padding) {
   2605 			void *zero;
   2606 
   2607 			zero = wapbl_alloc(padding);
   2608 			memset(zero, 0, padding);
   2609 			error = wapbl_circ_write(wl, zero, padding, &off);
   2610 			wapbl_free(zero, padding);
   2611 			if (error)
   2612 				return error;
   2613 		}
   2614 	}
   2615 	*offp = off;
   2616 	return 0;
   2617 }
   2618 
   2619 /*
   2620  * wapbl_write_revocations(wl, offp)
   2621  *
   2622  *	Write all pending deallocations in the current transaction from
   2623  *	wapbl_register_deallocation to the log on disk, adding to the
   2624  *	circular queue's head at byte offset *offp, and returning the
   2625  *	new head's byte offset in *offp.
   2626  */
   2627 static int
   2628 wapbl_write_revocations(struct wapbl *wl, off_t *offp)
   2629 {
   2630 	struct wapbl_wc_blocklist *wc =
   2631 	    (struct wapbl_wc_blocklist *)wl->wl_wc_scratch;
   2632 	struct wapbl_dealloc *wd, *lwd;
   2633 	int blocklen = 1<<wl->wl_log_dev_bshift;
   2634 	off_t off = *offp;
   2635 	int error;
   2636 
   2637 	KASSERT(rw_write_held(&wl->wl_rwlock));
   2638 
   2639 	if (wl->wl_dealloccnt == 0)
   2640 		return 0;
   2641 
   2642 	while ((wd = TAILQ_FIRST(&wl->wl_dealloclist)) != NULL) {
   2643 		wc->wc_type = WAPBL_WC_REVOCATIONS;
   2644 		wc->wc_len = blocklen;
   2645 		wc->wc_blkcount = 0;
   2646 		while (wd && (wc->wc_blkcount < wl->wl_brperjblock)) {
   2647 			wc->wc_blocks[wc->wc_blkcount].wc_daddr =
   2648 			    wd->wd_blkno;
   2649 			wc->wc_blocks[wc->wc_blkcount].wc_dlen =
   2650 			    wd->wd_len;
   2651 			wc->wc_blkcount++;
   2652 
   2653 			wd = TAILQ_NEXT(wd, wd_entries);
   2654 		}
   2655 		WAPBL_PRINTF(WAPBL_PRINT_WRITE,
   2656 		    ("wapbl_write_revocations: len = %u off = %"PRIdMAX"\n",
   2657 		    wc->wc_len, (intmax_t)off));
   2658 		error = wapbl_circ_write(wl, wc, blocklen, &off);
   2659 		if (error)
   2660 			return error;
   2661 
   2662 		/* free all successfully written deallocs */
   2663 		lwd = wd;
   2664 		while ((wd = TAILQ_FIRST(&wl->wl_dealloclist)) != NULL) {
   2665 			if (wd == lwd)
   2666 				break;
   2667 			wapbl_deallocation_free(wl, wd, true);
   2668 		}
   2669 	}
   2670 	*offp = off;
   2671 	return 0;
   2672 }
   2673 
   2674 /*
   2675  * wapbl_write_inodes(wl, offp)
   2676  *
   2677  *	Write all pending inode allocations in the current transaction
   2678  *	from wapbl_register_inode to the log on disk, adding to the
   2679  *	circular queue's head at byte offset *offp and returning the
   2680  *	new head's byte offset in *offp.
   2681  */
   2682 static int
   2683 wapbl_write_inodes(struct wapbl *wl, off_t *offp)
   2684 {
   2685 	struct wapbl_wc_inodelist *wc =
   2686 	    (struct wapbl_wc_inodelist *)wl->wl_wc_scratch;
   2687 	int i;
   2688 	int blocklen = 1 << wl->wl_log_dev_bshift;
   2689 	off_t off = *offp;
   2690 	int error;
   2691 
   2692 	struct wapbl_ino_head *wih;
   2693 	struct wapbl_ino *wi;
   2694 	int iph;
   2695 
   2696 	iph = (blocklen - offsetof(struct wapbl_wc_inodelist, wc_inodes)) /
   2697 	    sizeof(((struct wapbl_wc_inodelist *)0)->wc_inodes[0]);
   2698 
   2699 	i = 0;
   2700 	wih = &wl->wl_inohash[0];
   2701 	wi = 0;
   2702 	do {
   2703 		wc->wc_type = WAPBL_WC_INODES;
   2704 		wc->wc_len = blocklen;
   2705 		wc->wc_inocnt = 0;
   2706 		wc->wc_clear = (i == 0);
   2707 		while ((i < wl->wl_inohashcnt) && (wc->wc_inocnt < iph)) {
   2708 			while (!wi) {
   2709 				KASSERT((wih - &wl->wl_inohash[0])
   2710 				    <= wl->wl_inohashmask);
   2711 				wi = LIST_FIRST(wih++);
   2712 			}
   2713 			wc->wc_inodes[wc->wc_inocnt].wc_inumber = wi->wi_ino;
   2714 			wc->wc_inodes[wc->wc_inocnt].wc_imode = wi->wi_mode;
   2715 			wc->wc_inocnt++;
   2716 			i++;
   2717 			wi = LIST_NEXT(wi, wi_hash);
   2718 		}
   2719 		WAPBL_PRINTF(WAPBL_PRINT_WRITE,
   2720 		    ("wapbl_write_inodes: len = %u off = %"PRIdMAX"\n",
   2721 		    wc->wc_len, (intmax_t)off));
   2722 		error = wapbl_circ_write(wl, wc, blocklen, &off);
   2723 		if (error)
   2724 			return error;
   2725 	} while (i < wl->wl_inohashcnt);
   2726 
   2727 	*offp = off;
   2728 	return 0;
   2729 }
   2730 
   2731 #endif /* _KERNEL */
   2732 
   2733 /****************************************************************/
   2734 
   2735 struct wapbl_blk {
   2736 	LIST_ENTRY(wapbl_blk) wb_hash;
   2737 	daddr_t wb_blk;
   2738 	off_t wb_off; /* Offset of this block in the log */
   2739 };
   2740 #define	WAPBL_BLKPOOL_MIN 83
   2741 
   2742 static void
   2743 wapbl_blkhash_init(struct wapbl_replay *wr, u_int size)
   2744 {
   2745 	if (size < WAPBL_BLKPOOL_MIN)
   2746 		size = WAPBL_BLKPOOL_MIN;
   2747 	KASSERT(wr->wr_blkhash == 0);
   2748 #ifdef _KERNEL
   2749 	wr->wr_blkhash = hashinit(size, HASH_LIST, true, &wr->wr_blkhashmask);
   2750 #else /* ! _KERNEL */
   2751 	/* Manually implement hashinit */
   2752 	{
   2753 		unsigned long i, hashsize;
   2754 		for (hashsize = 1; hashsize < size; hashsize <<= 1)
   2755 			continue;
   2756 		wr->wr_blkhash = wapbl_alloc(hashsize * sizeof(*wr->wr_blkhash));
   2757 		for (i = 0; i < hashsize; i++)
   2758 			LIST_INIT(&wr->wr_blkhash[i]);
   2759 		wr->wr_blkhashmask = hashsize - 1;
   2760 	}
   2761 #endif /* ! _KERNEL */
   2762 }
   2763 
   2764 static void
   2765 wapbl_blkhash_free(struct wapbl_replay *wr)
   2766 {
   2767 	KASSERT(wr->wr_blkhashcnt == 0);
   2768 #ifdef _KERNEL
   2769 	hashdone(wr->wr_blkhash, HASH_LIST, wr->wr_blkhashmask);
   2770 #else /* ! _KERNEL */
   2771 	wapbl_free(wr->wr_blkhash,
   2772 	    (wr->wr_blkhashmask + 1) * sizeof(*wr->wr_blkhash));
   2773 #endif /* ! _KERNEL */
   2774 }
   2775 
   2776 static struct wapbl_blk *
   2777 wapbl_blkhash_get(struct wapbl_replay *wr, daddr_t blk)
   2778 {
   2779 	struct wapbl_blk_head *wbh;
   2780 	struct wapbl_blk *wb;
   2781 	wbh = &wr->wr_blkhash[blk & wr->wr_blkhashmask];
   2782 	LIST_FOREACH(wb, wbh, wb_hash) {
   2783 		if (blk == wb->wb_blk)
   2784 			return wb;
   2785 	}
   2786 	return 0;
   2787 }
   2788 
   2789 static void
   2790 wapbl_blkhash_ins(struct wapbl_replay *wr, daddr_t blk, off_t off)
   2791 {
   2792 	struct wapbl_blk_head *wbh;
   2793 	struct wapbl_blk *wb;
   2794 	wb = wapbl_blkhash_get(wr, blk);
   2795 	if (wb) {
   2796 		KASSERT(wb->wb_blk == blk);
   2797 		wb->wb_off = off;
   2798 	} else {
   2799 		wb = wapbl_alloc(sizeof(*wb));
   2800 		wb->wb_blk = blk;
   2801 		wb->wb_off = off;
   2802 		wbh = &wr->wr_blkhash[blk & wr->wr_blkhashmask];
   2803 		LIST_INSERT_HEAD(wbh, wb, wb_hash);
   2804 		wr->wr_blkhashcnt++;
   2805 	}
   2806 }
   2807 
   2808 static void
   2809 wapbl_blkhash_rem(struct wapbl_replay *wr, daddr_t blk)
   2810 {
   2811 	struct wapbl_blk *wb = wapbl_blkhash_get(wr, blk);
   2812 	if (wb) {
   2813 		KASSERT(wr->wr_blkhashcnt > 0);
   2814 		wr->wr_blkhashcnt--;
   2815 		LIST_REMOVE(wb, wb_hash);
   2816 		wapbl_free(wb, sizeof(*wb));
   2817 	}
   2818 }
   2819 
   2820 static void
   2821 wapbl_blkhash_clear(struct wapbl_replay *wr)
   2822 {
   2823 	unsigned long i;
   2824 	for (i = 0; i <= wr->wr_blkhashmask; i++) {
   2825 		struct wapbl_blk *wb;
   2826 
   2827 		while ((wb = LIST_FIRST(&wr->wr_blkhash[i]))) {
   2828 			KASSERT(wr->wr_blkhashcnt > 0);
   2829 			wr->wr_blkhashcnt--;
   2830 			LIST_REMOVE(wb, wb_hash);
   2831 			wapbl_free(wb, sizeof(*wb));
   2832 		}
   2833 	}
   2834 	KASSERT(wr->wr_blkhashcnt == 0);
   2835 }
   2836 
   2837 /****************************************************************/
   2838 
   2839 /*
   2840  * wapbl_circ_read(wr, data, len, offp)
   2841  *
   2842  *	Read len bytes into data from the circular queue of wr,
   2843  *	starting at the linear byte offset *offp, and returning the new
   2844  *	linear byte offset in *offp.
   2845  *
   2846  *	If the starting linear byte offset precedes wr->wr_circ_off,
   2847  *	the read instead begins at wr->wr_circ_off.  XXX WTF?  This
   2848  *	should be a KASSERT, not a conditional.
   2849  */
   2850 static int
   2851 wapbl_circ_read(struct wapbl_replay *wr, void *data, size_t len, off_t *offp)
   2852 {
   2853 	size_t slen;
   2854 	off_t off = *offp;
   2855 	int error;
   2856 	daddr_t pbn;
   2857 
   2858 	KASSERT(((len >> wr->wr_log_dev_bshift) <<
   2859 	    wr->wr_log_dev_bshift) == len);
   2860 
   2861 	if (off < wr->wr_circ_off)
   2862 		off = wr->wr_circ_off;
   2863 	slen = wr->wr_circ_off + wr->wr_circ_size - off;
   2864 	if (slen < len) {
   2865 		pbn = wr->wr_logpbn + (off >> wr->wr_log_dev_bshift);
   2866 #ifdef _KERNEL
   2867 		pbn = btodb(pbn << wr->wr_log_dev_bshift);
   2868 #endif
   2869 		error = wapbl_read(data, slen, wr->wr_devvp, pbn);
   2870 		if (error)
   2871 			return error;
   2872 		data = (uint8_t *)data + slen;
   2873 		len -= slen;
   2874 		off = wr->wr_circ_off;
   2875 	}
   2876 	pbn = wr->wr_logpbn + (off >> wr->wr_log_dev_bshift);
   2877 #ifdef _KERNEL
   2878 	pbn = btodb(pbn << wr->wr_log_dev_bshift);
   2879 #endif
   2880 	error = wapbl_read(data, len, wr->wr_devvp, pbn);
   2881 	if (error)
   2882 		return error;
   2883 	off += len;
   2884 	if (off >= wr->wr_circ_off + wr->wr_circ_size)
   2885 		off = wr->wr_circ_off;
   2886 	*offp = off;
   2887 	return 0;
   2888 }
   2889 
   2890 /*
   2891  * wapbl_circ_advance(wr, len, offp)
   2892  *
   2893  *	Compute the linear byte offset of the circular queue of wr that
   2894  *	is len bytes past *offp, and store it in *offp.
   2895  *
   2896  *	This is as if wapbl_circ_read, but without actually reading
   2897  *	anything.
   2898  *
   2899  *	If the starting linear byte offset precedes wr->wr_circ_off, it
   2900  *	is taken to be wr->wr_circ_off instead.  XXX WTF?  This should
   2901  *	be a KASSERT, not a conditional.
   2902  */
   2903 static void
   2904 wapbl_circ_advance(struct wapbl_replay *wr, size_t len, off_t *offp)
   2905 {
   2906 	size_t slen;
   2907 	off_t off = *offp;
   2908 
   2909 	KASSERT(((len >> wr->wr_log_dev_bshift) <<
   2910 	    wr->wr_log_dev_bshift) == len);
   2911 
   2912 	if (off < wr->wr_circ_off)
   2913 		off = wr->wr_circ_off;
   2914 	slen = wr->wr_circ_off + wr->wr_circ_size - off;
   2915 	if (slen < len) {
   2916 		len -= slen;
   2917 		off = wr->wr_circ_off;
   2918 	}
   2919 	off += len;
   2920 	if (off >= wr->wr_circ_off + wr->wr_circ_size)
   2921 		off = wr->wr_circ_off;
   2922 	*offp = off;
   2923 }
   2924 
   2925 /****************************************************************/
   2926 
   2927 int
   2928 wapbl_replay_start(struct wapbl_replay **wrp, struct vnode *vp,
   2929 	daddr_t off, size_t count, size_t blksize)
   2930 {
   2931 	struct wapbl_replay *wr;
   2932 	int error;
   2933 	struct vnode *devvp;
   2934 	daddr_t logpbn;
   2935 	uint8_t *scratch;
   2936 	struct wapbl_wc_header *wch;
   2937 	struct wapbl_wc_header *wch2;
   2938 	/* Use this until we read the actual log header */
   2939 	int log_dev_bshift = ilog2(blksize);
   2940 	size_t used;
   2941 	daddr_t pbn;
   2942 
   2943 	WAPBL_PRINTF(WAPBL_PRINT_REPLAY,
   2944 	    ("wapbl_replay_start: vp=%p off=%"PRId64 " count=%zu blksize=%zu\n",
   2945 	    vp, off, count, blksize));
   2946 
   2947 	if (off < 0)
   2948 		return EINVAL;
   2949 
   2950 	if (blksize < DEV_BSIZE)
   2951 		return EINVAL;
   2952 	if (blksize % DEV_BSIZE)
   2953 		return EINVAL;
   2954 
   2955 #ifdef _KERNEL
   2956 #if 0
   2957 	/* XXX vp->v_size isn't reliably set for VBLK devices,
   2958 	 * especially root.  However, we might still want to verify
   2959 	 * that the full load is readable */
   2960 	if ((off + count) * blksize > vp->v_size)
   2961 		return EINVAL;
   2962 #endif
   2963 	if ((error = VOP_BMAP(vp, off, &devvp, &logpbn, 0)) != 0) {
   2964 		return error;
   2965 	}
   2966 #else /* ! _KERNEL */
   2967 	devvp = vp;
   2968 	logpbn = off;
   2969 #endif /* ! _KERNEL */
   2970 
   2971 	scratch = wapbl_alloc(MAXBSIZE);
   2972 
   2973 	pbn = logpbn;
   2974 #ifdef _KERNEL
   2975 	pbn = btodb(pbn << log_dev_bshift);
   2976 #endif
   2977 	error = wapbl_read(scratch, 2<<log_dev_bshift, devvp, pbn);
   2978 	if (error)
   2979 		goto errout;
   2980 
   2981 	wch = (struct wapbl_wc_header *)scratch;
   2982 	wch2 =
   2983 	    (struct wapbl_wc_header *)(scratch + (1<<log_dev_bshift));
   2984 	/* XXX verify checksums and magic numbers */
   2985 	if (wch->wc_type != WAPBL_WC_HEADER) {
   2986 		printf("Unrecognized wapbl magic: 0x%08x\n", wch->wc_type);
   2987 		error = EFTYPE;
   2988 		goto errout;
   2989 	}
   2990 
   2991 	if (wch2->wc_generation > wch->wc_generation)
   2992 		wch = wch2;
   2993 
   2994 	wr = wapbl_calloc(1, sizeof(*wr));
   2995 
   2996 	wr->wr_logvp = vp;
   2997 	wr->wr_devvp = devvp;
   2998 	wr->wr_logpbn = logpbn;
   2999 
   3000 	wr->wr_scratch = scratch;
   3001 
   3002 	wr->wr_log_dev_bshift = wch->wc_log_dev_bshift;
   3003 	wr->wr_fs_dev_bshift = wch->wc_fs_dev_bshift;
   3004 	wr->wr_circ_off = wch->wc_circ_off;
   3005 	wr->wr_circ_size = wch->wc_circ_size;
   3006 	wr->wr_generation = wch->wc_generation;
   3007 
   3008 	used = wapbl_space_used(wch->wc_circ_size, wch->wc_head, wch->wc_tail);
   3009 
   3010 	WAPBL_PRINTF(WAPBL_PRINT_REPLAY,
   3011 	    ("wapbl_replay: head=%"PRId64" tail=%"PRId64" off=%"PRId64
   3012 	    " len=%"PRId64" used=%zu\n",
   3013 	    wch->wc_head, wch->wc_tail, wch->wc_circ_off,
   3014 	    wch->wc_circ_size, used));
   3015 
   3016 	wapbl_blkhash_init(wr, (used >> wch->wc_fs_dev_bshift));
   3017 
   3018 	error = wapbl_replay_process(wr, wch->wc_head, wch->wc_tail);
   3019 	if (error) {
   3020 		wapbl_replay_stop(wr);
   3021 		wapbl_replay_free(wr);
   3022 		return error;
   3023 	}
   3024 
   3025 	*wrp = wr;
   3026 	return 0;
   3027 
   3028  errout:
   3029 	wapbl_free(scratch, MAXBSIZE);
   3030 	return error;
   3031 }
   3032 
   3033 void
   3034 wapbl_replay_stop(struct wapbl_replay *wr)
   3035 {
   3036 
   3037 	if (!wapbl_replay_isopen(wr))
   3038 		return;
   3039 
   3040 	WAPBL_PRINTF(WAPBL_PRINT_REPLAY, ("wapbl_replay_stop called\n"));
   3041 
   3042 	wapbl_free(wr->wr_scratch, MAXBSIZE);
   3043 	wr->wr_scratch = NULL;
   3044 
   3045 	wr->wr_logvp = NULL;
   3046 
   3047 	wapbl_blkhash_clear(wr);
   3048 	wapbl_blkhash_free(wr);
   3049 }
   3050 
   3051 void
   3052 wapbl_replay_free(struct wapbl_replay *wr)
   3053 {
   3054 
   3055 	KDASSERT(!wapbl_replay_isopen(wr));
   3056 
   3057 	if (wr->wr_inodes)
   3058 		wapbl_free(wr->wr_inodes,
   3059 		    wr->wr_inodescnt * sizeof(wr->wr_inodes[0]));
   3060 	wapbl_free(wr, sizeof(*wr));
   3061 }
   3062 
   3063 #ifdef _KERNEL
   3064 int
   3065 wapbl_replay_isopen1(struct wapbl_replay *wr)
   3066 {
   3067 
   3068 	return wapbl_replay_isopen(wr);
   3069 }
   3070 #endif
   3071 
   3072 /*
   3073  * calculate the disk address for the i'th block in the wc_blockblist
   3074  * offset by j blocks of size blen.
   3075  *
   3076  * wc_daddr is always a kernel disk address in DEV_BSIZE units that
   3077  * was written to the journal.
   3078  *
   3079  * The kernel needs that address plus the offset in DEV_BSIZE units.
   3080  *
   3081  * Userland needs that address plus the offset in blen units.
   3082  *
   3083  */
   3084 static daddr_t
   3085 wapbl_block_daddr(struct wapbl_wc_blocklist *wc, int i, int j, int blen)
   3086 {
   3087 	daddr_t pbn;
   3088 
   3089 #ifdef _KERNEL
   3090 	pbn = wc->wc_blocks[i].wc_daddr + btodb(j * blen);
   3091 #else
   3092 	pbn = dbtob(wc->wc_blocks[i].wc_daddr) / blen + j;
   3093 #endif
   3094 
   3095 	return pbn;
   3096 }
   3097 
   3098 static void
   3099 wapbl_replay_process_blocks(struct wapbl_replay *wr, off_t *offp)
   3100 {
   3101 	struct wapbl_wc_blocklist *wc =
   3102 	    (struct wapbl_wc_blocklist *)wr->wr_scratch;
   3103 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   3104 	int i, j, n;
   3105 
   3106 	for (i = 0; i < wc->wc_blkcount; i++) {
   3107 		/*
   3108 		 * Enter each physical block into the hashtable independently.
   3109 		 */
   3110 		n = wc->wc_blocks[i].wc_dlen >> wr->wr_fs_dev_bshift;
   3111 		for (j = 0; j < n; j++) {
   3112 			wapbl_blkhash_ins(wr, wapbl_block_daddr(wc, i, j, fsblklen),
   3113 			    *offp);
   3114 			wapbl_circ_advance(wr, fsblklen, offp);
   3115 		}
   3116 	}
   3117 }
   3118 
   3119 static void
   3120 wapbl_replay_process_revocations(struct wapbl_replay *wr)
   3121 {
   3122 	struct wapbl_wc_blocklist *wc =
   3123 	    (struct wapbl_wc_blocklist *)wr->wr_scratch;
   3124 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   3125 	int i, j, n;
   3126 
   3127 	for (i = 0; i < wc->wc_blkcount; i++) {
   3128 		/*
   3129 		 * Remove any blocks found from the hashtable.
   3130 		 */
   3131 		n = wc->wc_blocks[i].wc_dlen >> wr->wr_fs_dev_bshift;
   3132 		for (j = 0; j < n; j++)
   3133 			wapbl_blkhash_rem(wr, wapbl_block_daddr(wc, i, j, fsblklen));
   3134 	}
   3135 }
   3136 
   3137 static void
   3138 wapbl_replay_process_inodes(struct wapbl_replay *wr, off_t oldoff, off_t newoff)
   3139 {
   3140 	struct wapbl_wc_inodelist *wc =
   3141 	    (struct wapbl_wc_inodelist *)wr->wr_scratch;
   3142 	void *new_inodes;
   3143 	const size_t oldsize = wr->wr_inodescnt * sizeof(wr->wr_inodes[0]);
   3144 
   3145 	KASSERT(sizeof(wr->wr_inodes[0]) == sizeof(wc->wc_inodes[0]));
   3146 
   3147 	/*
   3148 	 * Keep track of where we found this so location won't be
   3149 	 * overwritten.
   3150 	 */
   3151 	if (wc->wc_clear) {
   3152 		wr->wr_inodestail = oldoff;
   3153 		wr->wr_inodescnt = 0;
   3154 		if (wr->wr_inodes != NULL) {
   3155 			wapbl_free(wr->wr_inodes, oldsize);
   3156 			wr->wr_inodes = NULL;
   3157 		}
   3158 	}
   3159 	wr->wr_inodeshead = newoff;
   3160 	if (wc->wc_inocnt == 0)
   3161 		return;
   3162 
   3163 	new_inodes = wapbl_alloc((wr->wr_inodescnt + wc->wc_inocnt) *
   3164 	    sizeof(wr->wr_inodes[0]));
   3165 	if (wr->wr_inodes != NULL) {
   3166 		memcpy(new_inodes, wr->wr_inodes, oldsize);
   3167 		wapbl_free(wr->wr_inodes, oldsize);
   3168 	}
   3169 	wr->wr_inodes = new_inodes;
   3170 	memcpy(&wr->wr_inodes[wr->wr_inodescnt], wc->wc_inodes,
   3171 	    wc->wc_inocnt * sizeof(wr->wr_inodes[0]));
   3172 	wr->wr_inodescnt += wc->wc_inocnt;
   3173 }
   3174 
   3175 static int
   3176 wapbl_replay_process(struct wapbl_replay *wr, off_t head, off_t tail)
   3177 {
   3178 	off_t off;
   3179 	int error;
   3180 
   3181 	int logblklen = 1 << wr->wr_log_dev_bshift;
   3182 
   3183 	wapbl_blkhash_clear(wr);
   3184 
   3185 	off = tail;
   3186 	while (off != head) {
   3187 		struct wapbl_wc_null *wcn;
   3188 		off_t saveoff = off;
   3189 		error = wapbl_circ_read(wr, wr->wr_scratch, logblklen, &off);
   3190 		if (error)
   3191 			goto errout;
   3192 		wcn = (struct wapbl_wc_null *)wr->wr_scratch;
   3193 		switch (wcn->wc_type) {
   3194 		case WAPBL_WC_BLOCKS:
   3195 			wapbl_replay_process_blocks(wr, &off);
   3196 			break;
   3197 
   3198 		case WAPBL_WC_REVOCATIONS:
   3199 			wapbl_replay_process_revocations(wr);
   3200 			break;
   3201 
   3202 		case WAPBL_WC_INODES:
   3203 			wapbl_replay_process_inodes(wr, saveoff, off);
   3204 			break;
   3205 
   3206 		default:
   3207 			printf("Unrecognized wapbl type: 0x%08x\n",
   3208 			       wcn->wc_type);
   3209  			error = EFTYPE;
   3210 			goto errout;
   3211 		}
   3212 		wapbl_circ_advance(wr, wcn->wc_len, &saveoff);
   3213 		if (off != saveoff) {
   3214 			printf("wapbl_replay: corrupted records\n");
   3215 			error = EFTYPE;
   3216 			goto errout;
   3217 		}
   3218 	}
   3219 	return 0;
   3220 
   3221  errout:
   3222 	wapbl_blkhash_clear(wr);
   3223 	return error;
   3224 }
   3225 
   3226 #if 0
   3227 int
   3228 wapbl_replay_verify(struct wapbl_replay *wr, struct vnode *fsdevvp)
   3229 {
   3230 	off_t off;
   3231 	int mismatchcnt = 0;
   3232 	int logblklen = 1 << wr->wr_log_dev_bshift;
   3233 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   3234 	void *scratch1 = wapbl_alloc(MAXBSIZE);
   3235 	void *scratch2 = wapbl_alloc(MAXBSIZE);
   3236 	int error = 0;
   3237 
   3238 	KDASSERT(wapbl_replay_isopen(wr));
   3239 
   3240 	off = wch->wc_tail;
   3241 	while (off != wch->wc_head) {
   3242 		struct wapbl_wc_null *wcn;
   3243 #ifdef DEBUG
   3244 		off_t saveoff = off;
   3245 #endif
   3246 		error = wapbl_circ_read(wr, wr->wr_scratch, logblklen, &off);
   3247 		if (error)
   3248 			goto out;
   3249 		wcn = (struct wapbl_wc_null *)wr->wr_scratch;
   3250 		switch (wcn->wc_type) {
   3251 		case WAPBL_WC_BLOCKS:
   3252 			{
   3253 				struct wapbl_wc_blocklist *wc =
   3254 				    (struct wapbl_wc_blocklist *)wr->wr_scratch;
   3255 				int i;
   3256 				for (i = 0; i < wc->wc_blkcount; i++) {
   3257 					int foundcnt = 0;
   3258 					int dirtycnt = 0;
   3259 					int j, n;
   3260 					/*
   3261 					 * Check each physical block into the
   3262 					 * hashtable independently
   3263 					 */
   3264 					n = wc->wc_blocks[i].wc_dlen >>
   3265 					    wch->wc_fs_dev_bshift;
   3266 					for (j = 0; j < n; j++) {
   3267 						struct wapbl_blk *wb =
   3268 						   wapbl_blkhash_get(wr,
   3269 						   wapbl_block_daddr(wc, i, j, fsblklen));
   3270 						if (wb && (wb->wb_off == off)) {
   3271 							foundcnt++;
   3272 							error =
   3273 							    wapbl_circ_read(wr,
   3274 							    scratch1, fsblklen,
   3275 							    &off);
   3276 							if (error)
   3277 								goto out;
   3278 							error =
   3279 							    wapbl_read(scratch2,
   3280 							    fsblklen, fsdevvp,
   3281 							    wb->wb_blk);
   3282 							if (error)
   3283 								goto out;
   3284 							if (memcmp(scratch1,
   3285 								   scratch2,
   3286 								   fsblklen)) {
   3287 								printf(
   3288 		"wapbl_verify: mismatch block %"PRId64" at off %"PRIdMAX"\n",
   3289 		wb->wb_blk, (intmax_t)off);
   3290 								dirtycnt++;
   3291 								mismatchcnt++;
   3292 							}
   3293 						} else {
   3294 							wapbl_circ_advance(wr,
   3295 							    fsblklen, &off);
   3296 						}
   3297 					}
   3298 #if 0
   3299 					/*
   3300 					 * If all of the blocks in an entry
   3301 					 * are clean, then remove all of its
   3302 					 * blocks from the hashtable since they
   3303 					 * never will need replay.
   3304 					 */
   3305 					if ((foundcnt != 0) &&
   3306 					    (dirtycnt == 0)) {
   3307 						off = saveoff;
   3308 						wapbl_circ_advance(wr,
   3309 						    logblklen, &off);
   3310 						for (j = 0; j < n; j++) {
   3311 							struct wapbl_blk *wb =
   3312 							   wapbl_blkhash_get(wr,
   3313 							   wapbl_block_daddr(wc, i, j, fsblklen));
   3314 							if (wb &&
   3315 							  (wb->wb_off == off)) {
   3316 								wapbl_blkhash_rem(wr, wb->wb_blk);
   3317 							}
   3318 							wapbl_circ_advance(wr,
   3319 							    fsblklen, &off);
   3320 						}
   3321 					}
   3322 #endif
   3323 				}
   3324 			}
   3325 			break;
   3326 		case WAPBL_WC_REVOCATIONS:
   3327 		case WAPBL_WC_INODES:
   3328 			break;
   3329 		default:
   3330 			KASSERT(0);
   3331 		}
   3332 #ifdef DEBUG
   3333 		wapbl_circ_advance(wr, wcn->wc_len, &saveoff);
   3334 		KASSERT(off == saveoff);
   3335 #endif
   3336 	}
   3337  out:
   3338 	wapbl_free(scratch1, MAXBSIZE);
   3339 	wapbl_free(scratch2, MAXBSIZE);
   3340 	if (!error && mismatchcnt)
   3341 		error = EFTYPE;
   3342 	return error;
   3343 }
   3344 #endif
   3345 
   3346 int
   3347 wapbl_replay_write(struct wapbl_replay *wr, struct vnode *fsdevvp)
   3348 {
   3349 	struct wapbl_blk *wb;
   3350 	size_t i;
   3351 	off_t off;
   3352 	void *scratch;
   3353 	int error = 0;
   3354 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   3355 
   3356 	KDASSERT(wapbl_replay_isopen(wr));
   3357 
   3358 	scratch = wapbl_alloc(MAXBSIZE);
   3359 
   3360 	for (i = 0; i <= wr->wr_blkhashmask; ++i) {
   3361 		LIST_FOREACH(wb, &wr->wr_blkhash[i], wb_hash) {
   3362 			off = wb->wb_off;
   3363 			error = wapbl_circ_read(wr, scratch, fsblklen, &off);
   3364 			if (error)
   3365 				break;
   3366 			error = wapbl_write(scratch, fsblklen, fsdevvp,
   3367 			    wb->wb_blk);
   3368 			if (error)
   3369 				break;
   3370 		}
   3371 	}
   3372 
   3373 	wapbl_free(scratch, MAXBSIZE);
   3374 	return error;
   3375 }
   3376 
   3377 int
   3378 wapbl_replay_can_read(struct wapbl_replay *wr, daddr_t blk, long len)
   3379 {
   3380 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   3381 
   3382 	KDASSERT(wapbl_replay_isopen(wr));
   3383 	KASSERT((len % fsblklen) == 0);
   3384 
   3385 	while (len != 0) {
   3386 		struct wapbl_blk *wb = wapbl_blkhash_get(wr, blk);
   3387 		if (wb)
   3388 			return 1;
   3389 		len -= fsblklen;
   3390 	}
   3391 	return 0;
   3392 }
   3393 
   3394 int
   3395 wapbl_replay_read(struct wapbl_replay *wr, void *data, daddr_t blk, long len)
   3396 {
   3397 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   3398 
   3399 	KDASSERT(wapbl_replay_isopen(wr));
   3400 
   3401 	KASSERT((len % fsblklen) == 0);
   3402 
   3403 	while (len != 0) {
   3404 		struct wapbl_blk *wb = wapbl_blkhash_get(wr, blk);
   3405 		if (wb) {
   3406 			off_t off = wb->wb_off;
   3407 			int error;
   3408 			error = wapbl_circ_read(wr, data, fsblklen, &off);
   3409 			if (error)
   3410 				return error;
   3411 		}
   3412 		data = (uint8_t *)data + fsblklen;
   3413 		len -= fsblklen;
   3414 		blk++;
   3415 	}
   3416 	return 0;
   3417 }
   3418 
   3419 #ifdef _KERNEL
   3420 
   3421 MODULE(MODULE_CLASS_VFS, wapbl, NULL);
   3422 
   3423 static int
   3424 wapbl_modcmd(modcmd_t cmd, void *arg)
   3425 {
   3426 
   3427 	switch (cmd) {
   3428 	case MODULE_CMD_INIT:
   3429 		wapbl_init();
   3430 		return 0;
   3431 	case MODULE_CMD_FINI:
   3432 		return wapbl_fini();
   3433 	default:
   3434 		return ENOTTY;
   3435 	}
   3436 }
   3437 #endif /* _KERNEL */
   3438