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vfs_wapbl.c revision 1.85
      1 /*	$NetBSD: vfs_wapbl.c,v 1.85 2016/10/28 20:38:12 jdolecek 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 1.85 2016/10/28 20:38:12 jdolecek 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/file.h>
     52 #include <sys/kauth.h>
     53 #include <sys/kernel.h>
     54 #include <sys/module.h>
     55 #include <sys/mount.h>
     56 #include <sys/mutex.h>
     57 #include <sys/namei.h>
     58 #include <sys/proc.h>
     59 #include <sys/resourcevar.h>
     60 #include <sys/sysctl.h>
     61 #include <sys/uio.h>
     62 #include <sys/vnode.h>
     63 
     64 #include <miscfs/specfs/specdev.h>
     65 
     66 #define	wapbl_alloc(s) kmem_alloc((s), KM_SLEEP)
     67 #define	wapbl_free(a, s) kmem_free((a), (s))
     68 #define	wapbl_calloc(n, s) kmem_zalloc((n)*(s), KM_SLEEP)
     69 
     70 static struct sysctllog *wapbl_sysctl;
     71 static int wapbl_flush_disk_cache = 1;
     72 static int wapbl_verbose_commit = 0;
     73 
     74 static inline size_t wapbl_space_free(size_t, off_t, off_t);
     75 
     76 #else /* !_KERNEL */
     77 
     78 #include <assert.h>
     79 #include <errno.h>
     80 #include <stdbool.h>
     81 #include <stdio.h>
     82 #include <stdlib.h>
     83 #include <string.h>
     84 
     85 #define	KDASSERT(x) assert(x)
     86 #define	KASSERT(x) assert(x)
     87 #define	wapbl_alloc(s) malloc(s)
     88 #define	wapbl_free(a, s) free(a)
     89 #define	wapbl_calloc(n, s) calloc((n), (s))
     90 
     91 #endif /* !_KERNEL */
     92 
     93 /*
     94  * INTERNAL DATA STRUCTURES
     95  */
     96 
     97 /*
     98  * This structure holds per-mount log information.
     99  *
    100  * Legend:	a = atomic access only
    101  *		r = read-only after init
    102  *		l = rwlock held
    103  *		m = mutex held
    104  *		lm = rwlock held writing or mutex held
    105  *		u = unlocked access ok
    106  *		b = bufcache_lock held
    107  */
    108 LIST_HEAD(wapbl_ino_head, wapbl_ino);
    109 struct wapbl {
    110 	struct vnode *wl_logvp;	/* r:	log here */
    111 	struct vnode *wl_devvp;	/* r:	log on this device */
    112 	struct mount *wl_mount;	/* r:	mountpoint wl is associated with */
    113 	daddr_t wl_logpbn;	/* r:	Physical block number of start of log */
    114 	int wl_log_dev_bshift;	/* r:	logarithm of device block size of log
    115 					device */
    116 	int wl_fs_dev_bshift;	/* r:	logarithm of device block size of
    117 					filesystem device */
    118 
    119 	unsigned wl_lock_count;	/* m:	Count of transactions in progress */
    120 
    121 	size_t wl_circ_size; 	/* r:	Number of bytes in buffer of log */
    122 	size_t wl_circ_off;	/* r:	Number of bytes reserved at start */
    123 
    124 	size_t wl_bufcount_max;	/* r:	Number of buffers reserved for log */
    125 	size_t wl_bufbytes_max;	/* r:	Number of buf bytes reserved for log */
    126 
    127 	off_t wl_head;		/* l:	Byte offset of log head */
    128 	off_t wl_tail;		/* l:	Byte offset of log tail */
    129 	/*
    130 	 * WAPBL log layout, stored on wl_devvp at wl_logpbn:
    131 	 *
    132 	 *  ___________________ wl_circ_size __________________
    133 	 * /                                                   \
    134 	 * +---------+---------+-------+--------------+--------+
    135 	 * [ commit0 | commit1 | CCWCW | EEEEEEEEEEEE | CCCWCW ]
    136 	 * +---------+---------+-------+--------------+--------+
    137 	 *       wl_circ_off --^       ^-- wl_head    ^-- wl_tail
    138 	 *
    139 	 * commit0 and commit1 are commit headers.  A commit header has
    140 	 * a generation number, indicating which of the two headers is
    141 	 * more recent, and an assignment of head and tail pointers.
    142 	 * The rest is a circular queue of log records, starting at
    143 	 * the byte offset wl_circ_off.
    144 	 *
    145 	 * E marks empty space for records.
    146 	 * W marks records for block writes issued but waiting.
    147 	 * C marks completed records.
    148 	 *
    149 	 * wapbl_flush writes new records to empty `E' spaces after
    150 	 * wl_head from the current transaction in memory.
    151 	 *
    152 	 * wapbl_truncate advances wl_tail past any completed `C'
    153 	 * records, freeing them up for use.
    154 	 *
    155 	 * head == tail == 0 means log is empty.
    156 	 * head == tail != 0 means log is full.
    157 	 *
    158 	 * See assertions in wapbl_advance() for other boundary
    159 	 * conditions.
    160 	 *
    161 	 * Only wapbl_flush moves the head, except when wapbl_truncate
    162 	 * sets it to 0 to indicate that the log is empty.
    163 	 *
    164 	 * Only wapbl_truncate moves the tail, except when wapbl_flush
    165 	 * sets it to wl_circ_off to indicate that the log is full.
    166 	 */
    167 
    168 	struct wapbl_wc_header *wl_wc_header;	/* l	*/
    169 	void *wl_wc_scratch;	/* l:	scratch space (XXX: por que?!?) */
    170 
    171 	kmutex_t wl_mtx;	/* u:	short-term lock */
    172 	krwlock_t wl_rwlock;	/* u:	File system transaction lock */
    173 
    174 	/*
    175 	 * Must be held while accessing
    176 	 * wl_count or wl_bufs or head or tail
    177 	 */
    178 
    179 	/*
    180 	 * Callback called from within the flush routine to flush any extra
    181 	 * bits.  Note that flush may be skipped without calling this if
    182 	 * there are no outstanding buffers in the transaction.
    183 	 */
    184 #if _KERNEL
    185 	wapbl_flush_fn_t wl_flush;	/* r	*/
    186 	wapbl_flush_fn_t wl_flush_abort;/* r	*/
    187 #endif
    188 
    189 	size_t wl_bufbytes;	/* m:	Byte count of pages in wl_bufs */
    190 	size_t wl_bufcount;	/* m:	Count of buffers in wl_bufs */
    191 	size_t wl_bcount;	/* m:	Total bcount of wl_bufs */
    192 
    193 	LIST_HEAD(, buf) wl_bufs; /* m:	Buffers in current transaction */
    194 
    195 	kcondvar_t wl_reclaimable_cv;	/* m (obviously) */
    196 	size_t wl_reclaimable_bytes; /* m:	Amount of space available for
    197 						reclamation by truncate */
    198 	int wl_error_count;	/* m:	# of wl_entries with errors */
    199 	size_t wl_reserved_bytes; /* never truncate log smaller than this */
    200 
    201 #ifdef WAPBL_DEBUG_BUFBYTES
    202 	size_t wl_unsynced_bufbytes; /* Byte count of unsynced buffers */
    203 #endif
    204 
    205 #if _KERNEL
    206 	int wl_brperjblock;	/* r Block records per journal block */
    207 #endif
    208 
    209 	SIMPLEQ_HEAD(, wapbl_dealloc) wl_dealloclist;	/* lm:	list head */
    210 	int wl_dealloccnt;				/* lm:	total count */
    211 	int wl_dealloclim;				/* r:	max count */
    212 
    213 	/* hashtable of inode numbers for allocated but unlinked inodes */
    214 	/* synch ??? */
    215 	struct wapbl_ino_head *wl_inohash;
    216 	u_long wl_inohashmask;
    217 	int wl_inohashcnt;
    218 
    219 	SIMPLEQ_HEAD(, wapbl_entry) wl_entries; /* On disk transaction
    220 						   accounting */
    221 
    222 	u_char *wl_buffer;	/* l:   buffer for wapbl_buffered_write() */
    223 	daddr_t wl_buffer_dblk;	/* l:   buffer disk block address */
    224 	size_t wl_buffer_used;	/* l:   buffer current use */
    225 };
    226 
    227 #ifdef WAPBL_DEBUG_PRINT
    228 int wapbl_debug_print = WAPBL_DEBUG_PRINT;
    229 #endif
    230 
    231 /****************************************************************/
    232 #ifdef _KERNEL
    233 
    234 #ifdef WAPBL_DEBUG
    235 struct wapbl *wapbl_debug_wl;
    236 #endif
    237 
    238 static int wapbl_write_commit(struct wapbl *wl, off_t head, off_t tail);
    239 static int wapbl_write_blocks(struct wapbl *wl, off_t *offp);
    240 static int wapbl_write_revocations(struct wapbl *wl, off_t *offp);
    241 static int wapbl_write_inodes(struct wapbl *wl, off_t *offp);
    242 #endif /* _KERNEL */
    243 
    244 static int wapbl_replay_process(struct wapbl_replay *wr, off_t, off_t);
    245 
    246 static inline size_t wapbl_space_used(size_t avail, off_t head,
    247 	off_t tail);
    248 
    249 #ifdef _KERNEL
    250 
    251 static struct pool wapbl_entry_pool;
    252 static struct pool wapbl_dealloc_pool;
    253 
    254 #define	WAPBL_INODETRK_SIZE 83
    255 static int wapbl_ino_pool_refcount;
    256 static struct pool wapbl_ino_pool;
    257 struct wapbl_ino {
    258 	LIST_ENTRY(wapbl_ino) wi_hash;
    259 	ino_t wi_ino;
    260 	mode_t wi_mode;
    261 };
    262 
    263 static void wapbl_inodetrk_init(struct wapbl *wl, u_int size);
    264 static void wapbl_inodetrk_free(struct wapbl *wl);
    265 static struct wapbl_ino *wapbl_inodetrk_get(struct wapbl *wl, ino_t ino);
    266 
    267 static size_t wapbl_transaction_len(struct wapbl *wl);
    268 static inline size_t wapbl_transaction_inodes_len(struct wapbl *wl);
    269 
    270 #if 0
    271 int wapbl_replay_verify(struct wapbl_replay *, struct vnode *);
    272 #endif
    273 
    274 static int wapbl_replay_isopen1(struct wapbl_replay *);
    275 
    276 struct wapbl_ops wapbl_ops = {
    277 	.wo_wapbl_discard	= wapbl_discard,
    278 	.wo_wapbl_replay_isopen	= wapbl_replay_isopen1,
    279 	.wo_wapbl_replay_can_read = wapbl_replay_can_read,
    280 	.wo_wapbl_replay_read	= wapbl_replay_read,
    281 	.wo_wapbl_add_buf	= wapbl_add_buf,
    282 	.wo_wapbl_remove_buf	= wapbl_remove_buf,
    283 	.wo_wapbl_resize_buf	= wapbl_resize_buf,
    284 	.wo_wapbl_begin		= wapbl_begin,
    285 	.wo_wapbl_end		= wapbl_end,
    286 	.wo_wapbl_junlock_assert= wapbl_junlock_assert,
    287 
    288 	/* XXX: the following is only used to say "this is a wapbl buf" */
    289 	.wo_wapbl_biodone	= wapbl_biodone,
    290 };
    291 
    292 static int
    293 wapbl_sysctl_init(void)
    294 {
    295 	int rv;
    296 	const struct sysctlnode *rnode, *cnode;
    297 
    298 	wapbl_sysctl = NULL;
    299 
    300 	rv = sysctl_createv(&wapbl_sysctl, 0, NULL, &rnode,
    301 		       CTLFLAG_PERMANENT,
    302 		       CTLTYPE_NODE, "wapbl",
    303 		       SYSCTL_DESCR("WAPBL journaling options"),
    304 		       NULL, 0, NULL, 0,
    305 		       CTL_VFS, CTL_CREATE, CTL_EOL);
    306 	if (rv)
    307 		return rv;
    308 
    309 	rv = sysctl_createv(&wapbl_sysctl, 0, &rnode, &cnode,
    310 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    311 		       CTLTYPE_INT, "flush_disk_cache",
    312 		       SYSCTL_DESCR("flush disk cache"),
    313 		       NULL, 0, &wapbl_flush_disk_cache, 0,
    314 		       CTL_CREATE, CTL_EOL);
    315 	if (rv)
    316 		return rv;
    317 
    318 	rv = sysctl_createv(&wapbl_sysctl, 0, &rnode, &cnode,
    319 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    320 		       CTLTYPE_INT, "verbose_commit",
    321 		       SYSCTL_DESCR("show time and size of wapbl log commits"),
    322 		       NULL, 0, &wapbl_verbose_commit, 0,
    323 		       CTL_CREATE, CTL_EOL);
    324 	return rv;
    325 }
    326 
    327 static void
    328 wapbl_init(void)
    329 {
    330 
    331 	pool_init(&wapbl_entry_pool, sizeof(struct wapbl_entry), 0, 0, 0,
    332 	    "wapblentrypl", &pool_allocator_kmem, IPL_VM);
    333 	pool_init(&wapbl_dealloc_pool, sizeof(struct wapbl_dealloc), 0, 0, 0,
    334 	    "wapbldealloc", &pool_allocator_nointr, IPL_NONE);
    335 
    336 	wapbl_sysctl_init();
    337 }
    338 
    339 static int
    340 wapbl_fini(void)
    341 {
    342 
    343 	if (wapbl_sysctl != NULL)
    344 		 sysctl_teardown(&wapbl_sysctl);
    345 
    346 	pool_destroy(&wapbl_dealloc_pool);
    347 	pool_destroy(&wapbl_entry_pool);
    348 
    349 	return 0;
    350 }
    351 
    352 static int
    353 wapbl_start_flush_inodes(struct wapbl *wl, struct wapbl_replay *wr)
    354 {
    355 	int error, i;
    356 
    357 	WAPBL_PRINTF(WAPBL_PRINT_REPLAY,
    358 	    ("wapbl_start: reusing log with %d inodes\n", wr->wr_inodescnt));
    359 
    360 	/*
    361 	 * Its only valid to reuse the replay log if its
    362 	 * the same as the new log we just opened.
    363 	 */
    364 	KDASSERT(!wapbl_replay_isopen(wr));
    365 	KASSERT(wl->wl_devvp->v_type == VBLK);
    366 	KASSERT(wr->wr_devvp->v_type == VBLK);
    367 	KASSERT(wl->wl_devvp->v_rdev == wr->wr_devvp->v_rdev);
    368 	KASSERT(wl->wl_logpbn == wr->wr_logpbn);
    369 	KASSERT(wl->wl_circ_size == wr->wr_circ_size);
    370 	KASSERT(wl->wl_circ_off == wr->wr_circ_off);
    371 	KASSERT(wl->wl_log_dev_bshift == wr->wr_log_dev_bshift);
    372 	KASSERT(wl->wl_fs_dev_bshift == wr->wr_fs_dev_bshift);
    373 
    374 	wl->wl_wc_header->wc_generation = wr->wr_generation + 1;
    375 
    376 	for (i = 0; i < wr->wr_inodescnt; i++)
    377 		wapbl_register_inode(wl, wr->wr_inodes[i].wr_inumber,
    378 		    wr->wr_inodes[i].wr_imode);
    379 
    380 	/* Make sure new transaction won't overwrite old inodes list */
    381 	KDASSERT(wapbl_transaction_len(wl) <=
    382 	    wapbl_space_free(wl->wl_circ_size, wr->wr_inodeshead,
    383 	    wr->wr_inodestail));
    384 
    385 	wl->wl_head = wl->wl_tail = wr->wr_inodeshead;
    386 	wl->wl_reclaimable_bytes = wl->wl_reserved_bytes =
    387 	    wapbl_transaction_len(wl);
    388 
    389 	error = wapbl_write_inodes(wl, &wl->wl_head);
    390 	if (error)
    391 		return error;
    392 
    393 	KASSERT(wl->wl_head != wl->wl_tail);
    394 	KASSERT(wl->wl_head != 0);
    395 
    396 	return 0;
    397 }
    398 
    399 int
    400 wapbl_start(struct wapbl ** wlp, struct mount *mp, struct vnode *vp,
    401 	daddr_t off, size_t count, size_t blksize, struct wapbl_replay *wr,
    402 	wapbl_flush_fn_t flushfn, wapbl_flush_fn_t flushabortfn)
    403 {
    404 	struct wapbl *wl;
    405 	struct vnode *devvp;
    406 	daddr_t logpbn;
    407 	int error;
    408 	int log_dev_bshift = ilog2(blksize);
    409 	int fs_dev_bshift = log_dev_bshift;
    410 	int run;
    411 
    412 	WAPBL_PRINTF(WAPBL_PRINT_OPEN, ("wapbl_start: vp=%p off=%" PRId64
    413 	    " count=%zu blksize=%zu\n", vp, off, count, blksize));
    414 
    415 	if (log_dev_bshift > fs_dev_bshift) {
    416 		WAPBL_PRINTF(WAPBL_PRINT_OPEN,
    417 			("wapbl: log device's block size cannot be larger "
    418 			 "than filesystem's\n"));
    419 		/*
    420 		 * Not currently implemented, although it could be if
    421 		 * needed someday.
    422 		 */
    423 		return ENOSYS;
    424 	}
    425 
    426 	if (off < 0)
    427 		return EINVAL;
    428 
    429 	if (blksize < DEV_BSIZE)
    430 		return EINVAL;
    431 	if (blksize % DEV_BSIZE)
    432 		return EINVAL;
    433 
    434 	/* XXXTODO: verify that the full load is writable */
    435 
    436 	/*
    437 	 * XXX check for minimum log size
    438 	 * minimum is governed by minimum amount of space
    439 	 * to complete a transaction. (probably truncate)
    440 	 */
    441 	/* XXX for now pick something minimal */
    442 	if ((count * blksize) < MAXPHYS) {
    443 		return ENOSPC;
    444 	}
    445 
    446 	if ((error = VOP_BMAP(vp, off, &devvp, &logpbn, &run)) != 0) {
    447 		return error;
    448 	}
    449 
    450 	wl = wapbl_calloc(1, sizeof(*wl));
    451 	rw_init(&wl->wl_rwlock);
    452 	mutex_init(&wl->wl_mtx, MUTEX_DEFAULT, IPL_NONE);
    453 	cv_init(&wl->wl_reclaimable_cv, "wapblrec");
    454 	LIST_INIT(&wl->wl_bufs);
    455 	SIMPLEQ_INIT(&wl->wl_entries);
    456 
    457 	wl->wl_logvp = vp;
    458 	wl->wl_devvp = devvp;
    459 	wl->wl_mount = mp;
    460 	wl->wl_logpbn = logpbn;
    461 	wl->wl_log_dev_bshift = log_dev_bshift;
    462 	wl->wl_fs_dev_bshift = fs_dev_bshift;
    463 
    464 	wl->wl_flush = flushfn;
    465 	wl->wl_flush_abort = flushabortfn;
    466 
    467 	/* Reserve two log device blocks for the commit headers */
    468 	wl->wl_circ_off = 2<<wl->wl_log_dev_bshift;
    469 	wl->wl_circ_size = ((count * blksize) - wl->wl_circ_off);
    470 	/* truncate the log usage to a multiple of log_dev_bshift */
    471 	wl->wl_circ_size >>= wl->wl_log_dev_bshift;
    472 	wl->wl_circ_size <<= wl->wl_log_dev_bshift;
    473 
    474 	/*
    475 	 * wl_bufbytes_max limits the size of the in memory transaction space.
    476 	 * - Since buffers are allocated and accounted for in units of
    477 	 *   PAGE_SIZE it is required to be a multiple of PAGE_SIZE
    478 	 *   (i.e. 1<<PAGE_SHIFT)
    479 	 * - Since the log device has to be written in units of
    480 	 *   1<<wl_log_dev_bshift it is required to be a mulitple of
    481 	 *   1<<wl_log_dev_bshift.
    482 	 * - Since filesystem will provide data in units of 1<<wl_fs_dev_bshift,
    483 	 *   it is convenient to be a multiple of 1<<wl_fs_dev_bshift.
    484 	 * Therefore it must be multiple of the least common multiple of those
    485 	 * three quantities.  Fortunately, all of those quantities are
    486 	 * guaranteed to be a power of two, and the least common multiple of
    487 	 * a set of numbers which are all powers of two is simply the maximum
    488 	 * of those numbers.  Finally, the maximum logarithm of a power of two
    489 	 * is the same as the log of the maximum power of two.  So we can do
    490 	 * the following operations to size wl_bufbytes_max:
    491 	 */
    492 
    493 	/* XXX fix actual number of pages reserved per filesystem. */
    494 	wl->wl_bufbytes_max = MIN(wl->wl_circ_size, buf_memcalc() / 2);
    495 
    496 	/* Round wl_bufbytes_max to the largest power of two constraint */
    497 	wl->wl_bufbytes_max >>= PAGE_SHIFT;
    498 	wl->wl_bufbytes_max <<= PAGE_SHIFT;
    499 	wl->wl_bufbytes_max >>= wl->wl_log_dev_bshift;
    500 	wl->wl_bufbytes_max <<= wl->wl_log_dev_bshift;
    501 	wl->wl_bufbytes_max >>= wl->wl_fs_dev_bshift;
    502 	wl->wl_bufbytes_max <<= wl->wl_fs_dev_bshift;
    503 
    504 	/* XXX maybe use filesystem fragment size instead of 1024 */
    505 	/* XXX fix actual number of buffers reserved per filesystem. */
    506 	wl->wl_bufcount_max = (nbuf / 2) * 1024;
    507 
    508 	wl->wl_brperjblock = ((1<<wl->wl_log_dev_bshift)
    509 	    - offsetof(struct wapbl_wc_blocklist, wc_blocks)) /
    510 	    sizeof(((struct wapbl_wc_blocklist *)0)->wc_blocks[0]);
    511 	KASSERT(wl->wl_brperjblock > 0);
    512 
    513 	/* XXX tie this into resource estimation */
    514 	wl->wl_dealloclim = wl->wl_bufbytes_max / mp->mnt_stat.f_bsize / 2;
    515 	SIMPLEQ_INIT(&wl->wl_dealloclist);
    516 
    517 	wl->wl_buffer = wapbl_alloc(MAXPHYS);
    518 	wl->wl_buffer_used = 0;
    519 
    520 	wapbl_inodetrk_init(wl, WAPBL_INODETRK_SIZE);
    521 
    522 	/* Initialize the commit header */
    523 	{
    524 		struct wapbl_wc_header *wc;
    525 		size_t len = 1 << wl->wl_log_dev_bshift;
    526 		wc = wapbl_calloc(1, len);
    527 		wc->wc_type = WAPBL_WC_HEADER;
    528 		wc->wc_len = len;
    529 		wc->wc_circ_off = wl->wl_circ_off;
    530 		wc->wc_circ_size = wl->wl_circ_size;
    531 		/* XXX wc->wc_fsid */
    532 		wc->wc_log_dev_bshift = wl->wl_log_dev_bshift;
    533 		wc->wc_fs_dev_bshift = wl->wl_fs_dev_bshift;
    534 		wl->wl_wc_header = wc;
    535 		wl->wl_wc_scratch = wapbl_alloc(len);
    536 	}
    537 
    538 	/*
    539 	 * if there was an existing set of unlinked but
    540 	 * allocated inodes, preserve it in the new
    541 	 * log.
    542 	 */
    543 	if (wr && wr->wr_inodescnt) {
    544 		error = wapbl_start_flush_inodes(wl, wr);
    545 		if (error)
    546 			goto errout;
    547 	}
    548 
    549 	error = wapbl_write_commit(wl, wl->wl_head, wl->wl_tail);
    550 	if (error) {
    551 		goto errout;
    552 	}
    553 
    554 	*wlp = wl;
    555 #if defined(WAPBL_DEBUG)
    556 	wapbl_debug_wl = wl;
    557 #endif
    558 
    559 	return 0;
    560  errout:
    561 	wapbl_discard(wl);
    562 	wapbl_free(wl->wl_wc_scratch, wl->wl_wc_header->wc_len);
    563 	wapbl_free(wl->wl_wc_header, wl->wl_wc_header->wc_len);
    564 	wapbl_free(wl->wl_buffer, MAXPHYS);
    565 	wapbl_inodetrk_free(wl);
    566 	wapbl_free(wl, sizeof(*wl));
    567 
    568 	return error;
    569 }
    570 
    571 /*
    572  * Like wapbl_flush, only discards the transaction
    573  * completely
    574  */
    575 
    576 void
    577 wapbl_discard(struct wapbl *wl)
    578 {
    579 	struct wapbl_entry *we;
    580 	struct wapbl_dealloc *wd;
    581 	struct buf *bp;
    582 	int i;
    583 
    584 	/*
    585 	 * XXX we may consider using upgrade here
    586 	 * if we want to call flush from inside a transaction
    587 	 */
    588 	rw_enter(&wl->wl_rwlock, RW_WRITER);
    589 	wl->wl_flush(wl->wl_mount, SIMPLEQ_FIRST(&wl->wl_dealloclist));
    590 
    591 #ifdef WAPBL_DEBUG_PRINT
    592 	{
    593 		pid_t pid = -1;
    594 		lwpid_t lid = -1;
    595 		if (curproc)
    596 			pid = curproc->p_pid;
    597 		if (curlwp)
    598 			lid = curlwp->l_lid;
    599 #ifdef WAPBL_DEBUG_BUFBYTES
    600 		WAPBL_PRINTF(WAPBL_PRINT_DISCARD,
    601 		    ("wapbl_discard: thread %d.%d discarding "
    602 		    "transaction\n"
    603 		    "\tbufcount=%zu bufbytes=%zu bcount=%zu "
    604 		    "deallocs=%d inodes=%d\n"
    605 		    "\terrcnt = %u, reclaimable=%zu reserved=%zu "
    606 		    "unsynced=%zu\n",
    607 		    pid, lid, wl->wl_bufcount, wl->wl_bufbytes,
    608 		    wl->wl_bcount, wl->wl_dealloccnt,
    609 		    wl->wl_inohashcnt, wl->wl_error_count,
    610 		    wl->wl_reclaimable_bytes, wl->wl_reserved_bytes,
    611 		    wl->wl_unsynced_bufbytes));
    612 		SIMPLEQ_FOREACH(we, &wl->wl_entries, we_entries) {
    613 			WAPBL_PRINTF(WAPBL_PRINT_DISCARD,
    614 			    ("\tentry: bufcount = %zu, reclaimable = %zu, "
    615 			     "error = %d, unsynced = %zu\n",
    616 			     we->we_bufcount, we->we_reclaimable_bytes,
    617 			     we->we_error, we->we_unsynced_bufbytes));
    618 		}
    619 #else /* !WAPBL_DEBUG_BUFBYTES */
    620 		WAPBL_PRINTF(WAPBL_PRINT_DISCARD,
    621 		    ("wapbl_discard: thread %d.%d discarding transaction\n"
    622 		    "\tbufcount=%zu bufbytes=%zu bcount=%zu "
    623 		    "deallocs=%d inodes=%d\n"
    624 		    "\terrcnt = %u, reclaimable=%zu reserved=%zu\n",
    625 		    pid, lid, wl->wl_bufcount, wl->wl_bufbytes,
    626 		    wl->wl_bcount, wl->wl_dealloccnt,
    627 		    wl->wl_inohashcnt, wl->wl_error_count,
    628 		    wl->wl_reclaimable_bytes, wl->wl_reserved_bytes));
    629 		SIMPLEQ_FOREACH(we, &wl->wl_entries, we_entries) {
    630 			WAPBL_PRINTF(WAPBL_PRINT_DISCARD,
    631 			    ("\tentry: bufcount = %zu, reclaimable = %zu, "
    632 			     "error = %d\n",
    633 			     we->we_bufcount, we->we_reclaimable_bytes,
    634 			     we->we_error));
    635 		}
    636 #endif /* !WAPBL_DEBUG_BUFBYTES */
    637 	}
    638 #endif /* WAPBL_DEBUG_PRINT */
    639 
    640 	for (i = 0; i <= wl->wl_inohashmask; i++) {
    641 		struct wapbl_ino_head *wih;
    642 		struct wapbl_ino *wi;
    643 
    644 		wih = &wl->wl_inohash[i];
    645 		while ((wi = LIST_FIRST(wih)) != NULL) {
    646 			LIST_REMOVE(wi, wi_hash);
    647 			pool_put(&wapbl_ino_pool, wi);
    648 			KASSERT(wl->wl_inohashcnt > 0);
    649 			wl->wl_inohashcnt--;
    650 		}
    651 	}
    652 
    653 	/*
    654 	 * clean buffer list
    655 	 */
    656 	mutex_enter(&bufcache_lock);
    657 	mutex_enter(&wl->wl_mtx);
    658 	while ((bp = LIST_FIRST(&wl->wl_bufs)) != NULL) {
    659 		if (bbusy(bp, 0, 0, &wl->wl_mtx) == 0) {
    660 			/*
    661 			 * The buffer will be unlocked and
    662 			 * removed from the transaction in brelse
    663 			 */
    664 			mutex_exit(&wl->wl_mtx);
    665 			brelsel(bp, 0);
    666 			mutex_enter(&wl->wl_mtx);
    667 		}
    668 	}
    669 	mutex_exit(&wl->wl_mtx);
    670 	mutex_exit(&bufcache_lock);
    671 
    672 	/*
    673 	 * Remove references to this wl from wl_entries, free any which
    674 	 * no longer have buffers, others will be freed in wapbl_biodone
    675 	 * when they no longer have any buffers.
    676 	 */
    677 	while ((we = SIMPLEQ_FIRST(&wl->wl_entries)) != NULL) {
    678 		SIMPLEQ_REMOVE_HEAD(&wl->wl_entries, we_entries);
    679 		/* XXX should we be accumulating wl_error_count
    680 		 * and increasing reclaimable bytes ? */
    681 		we->we_wapbl = NULL;
    682 		if (we->we_bufcount == 0) {
    683 #ifdef WAPBL_DEBUG_BUFBYTES
    684 			KASSERT(we->we_unsynced_bufbytes == 0);
    685 #endif
    686 			pool_put(&wapbl_entry_pool, we);
    687 		}
    688 	}
    689 
    690 	/* Discard list of deallocs */
    691 	while ((wd = SIMPLEQ_FIRST(&wl->wl_dealloclist)) != NULL) {
    692 		SIMPLEQ_REMOVE_HEAD(&wl->wl_dealloclist, wd_entries);
    693 		pool_put(&wapbl_dealloc_pool, wd);
    694 		wl->wl_dealloccnt--;
    695 	}
    696 
    697 	/* XXX should we clear wl_reserved_bytes? */
    698 
    699 	KASSERT(wl->wl_bufbytes == 0);
    700 	KASSERT(wl->wl_bcount == 0);
    701 	KASSERT(wl->wl_bufcount == 0);
    702 	KASSERT(LIST_EMPTY(&wl->wl_bufs));
    703 	KASSERT(SIMPLEQ_EMPTY(&wl->wl_entries));
    704 	KASSERT(wl->wl_inohashcnt == 0);
    705 	KASSERT(SIMPLEQ_EMPTY(&wl->wl_dealloclist));
    706 	KASSERT(wl->wl_dealloccnt == 0);
    707 
    708 	rw_exit(&wl->wl_rwlock);
    709 }
    710 
    711 int
    712 wapbl_stop(struct wapbl *wl, int force)
    713 {
    714 	int error;
    715 
    716 	WAPBL_PRINTF(WAPBL_PRINT_OPEN, ("wapbl_stop called\n"));
    717 	error = wapbl_flush(wl, 1);
    718 	if (error) {
    719 		if (force)
    720 			wapbl_discard(wl);
    721 		else
    722 			return error;
    723 	}
    724 
    725 	/* Unlinked inodes persist after a flush */
    726 	if (wl->wl_inohashcnt) {
    727 		if (force) {
    728 			wapbl_discard(wl);
    729 		} else {
    730 			return EBUSY;
    731 		}
    732 	}
    733 
    734 	KASSERT(wl->wl_bufbytes == 0);
    735 	KASSERT(wl->wl_bcount == 0);
    736 	KASSERT(wl->wl_bufcount == 0);
    737 	KASSERT(LIST_EMPTY(&wl->wl_bufs));
    738 	KASSERT(wl->wl_dealloccnt == 0);
    739 	KASSERT(SIMPLEQ_EMPTY(&wl->wl_entries));
    740 	KASSERT(wl->wl_inohashcnt == 0);
    741 	KASSERT(SIMPLEQ_EMPTY(&wl->wl_dealloclist));
    742 	KASSERT(wl->wl_dealloccnt == 0);
    743 
    744 	wapbl_free(wl->wl_wc_scratch, wl->wl_wc_header->wc_len);
    745 	wapbl_free(wl->wl_wc_header, wl->wl_wc_header->wc_len);
    746 	wapbl_free(wl->wl_buffer, MAXPHYS);
    747 	wapbl_inodetrk_free(wl);
    748 
    749 	cv_destroy(&wl->wl_reclaimable_cv);
    750 	mutex_destroy(&wl->wl_mtx);
    751 	rw_destroy(&wl->wl_rwlock);
    752 	wapbl_free(wl, sizeof(*wl));
    753 
    754 	return 0;
    755 }
    756 
    757 /****************************************************************/
    758 /*
    759  * Unbuffered disk I/O
    760  */
    761 
    762 static int
    763 wapbl_doio(void *data, size_t len, struct vnode *devvp, daddr_t pbn, int flags)
    764 {
    765 	struct pstats *pstats = curlwp->l_proc->p_stats;
    766 	struct buf *bp;
    767 	int error;
    768 
    769 	KASSERT((flags & ~(B_WRITE | B_READ)) == 0);
    770 	KASSERT(devvp->v_type == VBLK);
    771 
    772 	if ((flags & (B_WRITE | B_READ)) == B_WRITE) {
    773 		mutex_enter(devvp->v_interlock);
    774 		devvp->v_numoutput++;
    775 		mutex_exit(devvp->v_interlock);
    776 		pstats->p_ru.ru_oublock++;
    777 	} else {
    778 		pstats->p_ru.ru_inblock++;
    779 	}
    780 
    781 	bp = getiobuf(devvp, true);
    782 	bp->b_flags = flags;
    783 	bp->b_cflags = BC_BUSY; /* silly & dubious */
    784 	bp->b_dev = devvp->v_rdev;
    785 	bp->b_data = data;
    786 	bp->b_bufsize = bp->b_resid = bp->b_bcount = len;
    787 	bp->b_blkno = pbn;
    788 	BIO_SETPRIO(bp, BPRIO_TIMECRITICAL);
    789 
    790 	WAPBL_PRINTF(WAPBL_PRINT_IO,
    791 	    ("wapbl_doio: %s %d bytes at block %"PRId64" on dev 0x%"PRIx64"\n",
    792 	    BUF_ISWRITE(bp) ? "write" : "read", bp->b_bcount,
    793 	    bp->b_blkno, bp->b_dev));
    794 
    795 	VOP_STRATEGY(devvp, bp);
    796 
    797 	error = biowait(bp);
    798 	putiobuf(bp);
    799 
    800 	if (error) {
    801 		WAPBL_PRINTF(WAPBL_PRINT_ERROR,
    802 		    ("wapbl_doio: %s %zu bytes at block %" PRId64
    803 		    " on dev 0x%"PRIx64" failed with error %d\n",
    804 		    (((flags & (B_WRITE | B_READ)) == B_WRITE) ?
    805 		     "write" : "read"),
    806 		    len, pbn, devvp->v_rdev, error));
    807 	}
    808 
    809 	return error;
    810 }
    811 
    812 /*
    813  * wapbl_write(data, len, devvp, pbn)
    814  *
    815  *	Synchronously write len bytes from data to physical block pbn
    816  *	on devvp.
    817  */
    818 int
    819 wapbl_write(void *data, size_t len, struct vnode *devvp, daddr_t pbn)
    820 {
    821 
    822 	return wapbl_doio(data, len, devvp, pbn, B_WRITE);
    823 }
    824 
    825 /*
    826  * wapbl_read(data, len, devvp, pbn)
    827  *
    828  *	Synchronously read len bytes into data from physical block pbn
    829  *	on devvp.
    830  */
    831 int
    832 wapbl_read(void *data, size_t len, struct vnode *devvp, daddr_t pbn)
    833 {
    834 
    835 	return wapbl_doio(data, len, devvp, pbn, B_READ);
    836 }
    837 
    838 /****************************************************************/
    839 /*
    840  * Buffered disk writes -- try to coalesce writes and emit
    841  * MAXPHYS-aligned blocks.
    842  */
    843 
    844 /*
    845  * wapbl_buffered_flush(wl)
    846  *
    847  *	Flush any buffered writes from wapbl_buffered_write.
    848  */
    849 static int
    850 wapbl_buffered_flush(struct wapbl *wl)
    851 {
    852 	int error;
    853 
    854 	if (wl->wl_buffer_used == 0)
    855 		return 0;
    856 
    857 	error = wapbl_doio(wl->wl_buffer, wl->wl_buffer_used,
    858 	    wl->wl_devvp, wl->wl_buffer_dblk, B_WRITE);
    859 	wl->wl_buffer_used = 0;
    860 
    861 	return error;
    862 }
    863 
    864 /*
    865  * wapbl_buffered_write(data, len, wl, pbn)
    866  *
    867  *	Write len bytes from data to physical block pbn on
    868  *	wl->wl_devvp.  The write may not complete until
    869  *	wapbl_buffered_flush.
    870  */
    871 static int
    872 wapbl_buffered_write(void *data, size_t len, struct wapbl *wl, daddr_t pbn)
    873 {
    874 	int error;
    875 	size_t resid;
    876 
    877 	/*
    878 	 * If not adjacent to buffered data flush first.  Disk block
    879 	 * address is always valid for non-empty buffer.
    880 	 */
    881 	if (wl->wl_buffer_used > 0 &&
    882 	    pbn != wl->wl_buffer_dblk + btodb(wl->wl_buffer_used)) {
    883 		error = wapbl_buffered_flush(wl);
    884 		if (error)
    885 			return error;
    886 	}
    887 	/*
    888 	 * If this write goes to an empty buffer we have to
    889 	 * save the disk block address first.
    890 	 */
    891 	if (wl->wl_buffer_used == 0)
    892 		wl->wl_buffer_dblk = pbn;
    893 	/*
    894 	 * Remaining space so this buffer ends on a MAXPHYS boundary.
    895 	 *
    896 	 * Cannot become less or equal zero as the buffer would have been
    897 	 * flushed on the last call then.
    898 	 */
    899 	resid = MAXPHYS - dbtob(wl->wl_buffer_dblk % btodb(MAXPHYS)) -
    900 	    wl->wl_buffer_used;
    901 	KASSERT(resid > 0);
    902 	KASSERT(dbtob(btodb(resid)) == resid);
    903 	if (len >= resid) {
    904 		memcpy(wl->wl_buffer + wl->wl_buffer_used, data, resid);
    905 		wl->wl_buffer_used += resid;
    906 		error = wapbl_doio(wl->wl_buffer, wl->wl_buffer_used,
    907 		    wl->wl_devvp, wl->wl_buffer_dblk, B_WRITE);
    908 		data = (uint8_t *)data + resid;
    909 		len -= resid;
    910 		wl->wl_buffer_dblk = pbn + btodb(resid);
    911 		wl->wl_buffer_used = 0;
    912 		if (error)
    913 			return error;
    914 	}
    915 	KASSERT(len < MAXPHYS);
    916 	if (len > 0) {
    917 		memcpy(wl->wl_buffer + wl->wl_buffer_used, data, len);
    918 		wl->wl_buffer_used += len;
    919 	}
    920 
    921 	return 0;
    922 }
    923 
    924 /*
    925  * wapbl_circ_write(wl, data, len, offp)
    926  *
    927  *	Write len bytes from data to the circular queue of wl, starting
    928  *	at linear byte offset *offp, and returning the new linear byte
    929  *	offset in *offp.
    930  *
    931  *	If the starting linear byte offset precedes wl->wl_circ_off,
    932  *	the write instead begins at wl->wl_circ_off.  XXX WTF?  This
    933  *	should be a KASSERT, not a conditional.
    934  *
    935  *	The write is buffered in wl and must be flushed with
    936  *	wapbl_buffered_flush before it will be submitted to the disk.
    937  */
    938 static int
    939 wapbl_circ_write(struct wapbl *wl, void *data, size_t len, off_t *offp)
    940 {
    941 	size_t slen;
    942 	off_t off = *offp;
    943 	int error;
    944 	daddr_t pbn;
    945 
    946 	KDASSERT(((len >> wl->wl_log_dev_bshift) <<
    947 	    wl->wl_log_dev_bshift) == len);
    948 
    949 	if (off < wl->wl_circ_off)
    950 		off = wl->wl_circ_off;
    951 	slen = wl->wl_circ_off + wl->wl_circ_size - off;
    952 	if (slen < len) {
    953 		pbn = wl->wl_logpbn + (off >> wl->wl_log_dev_bshift);
    954 #ifdef _KERNEL
    955 		pbn = btodb(pbn << wl->wl_log_dev_bshift);
    956 #endif
    957 		error = wapbl_buffered_write(data, slen, wl, pbn);
    958 		if (error)
    959 			return error;
    960 		data = (uint8_t *)data + slen;
    961 		len -= slen;
    962 		off = wl->wl_circ_off;
    963 	}
    964 	pbn = wl->wl_logpbn + (off >> wl->wl_log_dev_bshift);
    965 #ifdef _KERNEL
    966 	pbn = btodb(pbn << wl->wl_log_dev_bshift);
    967 #endif
    968 	error = wapbl_buffered_write(data, len, wl, pbn);
    969 	if (error)
    970 		return error;
    971 	off += len;
    972 	if (off >= wl->wl_circ_off + wl->wl_circ_size)
    973 		off = wl->wl_circ_off;
    974 	*offp = off;
    975 	return 0;
    976 }
    977 
    978 /****************************************************************/
    979 /*
    980  * WAPBL transactions: entering, adding/removing bufs, and exiting
    981  */
    982 
    983 int
    984 wapbl_begin(struct wapbl *wl, const char *file, int line)
    985 {
    986 	int doflush;
    987 	unsigned lockcount;
    988 
    989 	KDASSERT(wl);
    990 
    991 	/*
    992 	 * XXX this needs to be made much more sophisticated.
    993 	 * perhaps each wapbl_begin could reserve a specified
    994 	 * number of buffers and bytes.
    995 	 */
    996 	mutex_enter(&wl->wl_mtx);
    997 	lockcount = wl->wl_lock_count;
    998 	doflush = ((wl->wl_bufbytes + (lockcount * MAXPHYS)) >
    999 		   wl->wl_bufbytes_max / 2) ||
   1000 		  ((wl->wl_bufcount + (lockcount * 10)) >
   1001 		   wl->wl_bufcount_max / 2) ||
   1002 		  (wapbl_transaction_len(wl) > wl->wl_circ_size / 2) ||
   1003 		  (wl->wl_dealloccnt >= (wl->wl_dealloclim / 2));
   1004 	mutex_exit(&wl->wl_mtx);
   1005 
   1006 	if (doflush) {
   1007 		WAPBL_PRINTF(WAPBL_PRINT_FLUSH,
   1008 		    ("force flush lockcnt=%d bufbytes=%zu "
   1009 		    "(max=%zu) bufcount=%zu (max=%zu) "
   1010 		    "dealloccnt %d (lim=%d)\n",
   1011 		    lockcount, wl->wl_bufbytes,
   1012 		    wl->wl_bufbytes_max, wl->wl_bufcount,
   1013 		    wl->wl_bufcount_max,
   1014 		    wl->wl_dealloccnt, wl->wl_dealloclim));
   1015 	}
   1016 
   1017 	if (doflush) {
   1018 		int error = wapbl_flush(wl, 0);
   1019 		if (error)
   1020 			return error;
   1021 	}
   1022 
   1023 	rw_enter(&wl->wl_rwlock, RW_READER);
   1024 	mutex_enter(&wl->wl_mtx);
   1025 	wl->wl_lock_count++;
   1026 	mutex_exit(&wl->wl_mtx);
   1027 
   1028 #if defined(WAPBL_DEBUG_PRINT)
   1029 	WAPBL_PRINTF(WAPBL_PRINT_TRANSACTION,
   1030 	    ("wapbl_begin thread %d.%d with bufcount=%zu "
   1031 	    "bufbytes=%zu bcount=%zu at %s:%d\n",
   1032 	    curproc->p_pid, curlwp->l_lid, wl->wl_bufcount,
   1033 	    wl->wl_bufbytes, wl->wl_bcount, file, line));
   1034 #endif
   1035 
   1036 	return 0;
   1037 }
   1038 
   1039 void
   1040 wapbl_end(struct wapbl *wl)
   1041 {
   1042 
   1043 #if defined(WAPBL_DEBUG_PRINT)
   1044 	WAPBL_PRINTF(WAPBL_PRINT_TRANSACTION,
   1045 	     ("wapbl_end thread %d.%d with bufcount=%zu "
   1046 	      "bufbytes=%zu bcount=%zu\n",
   1047 	      curproc->p_pid, curlwp->l_lid, wl->wl_bufcount,
   1048 	      wl->wl_bufbytes, wl->wl_bcount));
   1049 #endif
   1050 
   1051 	/*
   1052 	 * XXX this could be handled more gracefully, perhaps place
   1053 	 * only a partial transaction in the log and allow the
   1054 	 * remaining to flush without the protection of the journal.
   1055 	 */
   1056 	KASSERTMSG((wapbl_transaction_len(wl) <=
   1057 		(wl->wl_circ_size - wl->wl_reserved_bytes)),
   1058 	    "wapbl_end: current transaction too big to flush");
   1059 
   1060 	mutex_enter(&wl->wl_mtx);
   1061 	KASSERT(wl->wl_lock_count > 0);
   1062 	wl->wl_lock_count--;
   1063 	mutex_exit(&wl->wl_mtx);
   1064 
   1065 	rw_exit(&wl->wl_rwlock);
   1066 }
   1067 
   1068 void
   1069 wapbl_add_buf(struct wapbl *wl, struct buf * bp)
   1070 {
   1071 
   1072 	KASSERT(bp->b_cflags & BC_BUSY);
   1073 	KASSERT(bp->b_vp);
   1074 
   1075 	wapbl_jlock_assert(wl);
   1076 
   1077 #if 0
   1078 	/*
   1079 	 * XXX this might be an issue for swapfiles.
   1080 	 * see uvm_swap.c:1702
   1081 	 *
   1082 	 * XXX2 why require it then?  leap of semantics?
   1083 	 */
   1084 	KASSERT((bp->b_cflags & BC_NOCACHE) == 0);
   1085 #endif
   1086 
   1087 	mutex_enter(&wl->wl_mtx);
   1088 	if (bp->b_flags & B_LOCKED) {
   1089 		LIST_REMOVE(bp, b_wapbllist);
   1090 		WAPBL_PRINTF(WAPBL_PRINT_BUFFER2,
   1091 		   ("wapbl_add_buf thread %d.%d re-adding buf %p "
   1092 		    "with %d bytes %d bcount\n",
   1093 		    curproc->p_pid, curlwp->l_lid, bp, bp->b_bufsize,
   1094 		    bp->b_bcount));
   1095 	} else {
   1096 		/* unlocked by dirty buffers shouldn't exist */
   1097 		KASSERT(!(bp->b_oflags & BO_DELWRI));
   1098 		wl->wl_bufbytes += bp->b_bufsize;
   1099 		wl->wl_bcount += bp->b_bcount;
   1100 		wl->wl_bufcount++;
   1101 		WAPBL_PRINTF(WAPBL_PRINT_BUFFER,
   1102 		   ("wapbl_add_buf thread %d.%d adding buf %p "
   1103 		    "with %d bytes %d bcount\n",
   1104 		    curproc->p_pid, curlwp->l_lid, bp, bp->b_bufsize,
   1105 		    bp->b_bcount));
   1106 	}
   1107 	LIST_INSERT_HEAD(&wl->wl_bufs, bp, b_wapbllist);
   1108 	mutex_exit(&wl->wl_mtx);
   1109 
   1110 	bp->b_flags |= B_LOCKED;
   1111 }
   1112 
   1113 static void
   1114 wapbl_remove_buf_locked(struct wapbl * wl, struct buf *bp)
   1115 {
   1116 
   1117 	KASSERT(mutex_owned(&wl->wl_mtx));
   1118 	KASSERT(bp->b_cflags & BC_BUSY);
   1119 	wapbl_jlock_assert(wl);
   1120 
   1121 #if 0
   1122 	/*
   1123 	 * XXX this might be an issue for swapfiles.
   1124 	 * see uvm_swap.c:1725
   1125 	 *
   1126 	 * XXXdeux: see above
   1127 	 */
   1128 	KASSERT((bp->b_flags & BC_NOCACHE) == 0);
   1129 #endif
   1130 	KASSERT(bp->b_flags & B_LOCKED);
   1131 
   1132 	WAPBL_PRINTF(WAPBL_PRINT_BUFFER,
   1133 	   ("wapbl_remove_buf thread %d.%d removing buf %p with "
   1134 	    "%d bytes %d bcount\n",
   1135 	    curproc->p_pid, curlwp->l_lid, bp, bp->b_bufsize, bp->b_bcount));
   1136 
   1137 	KASSERT(wl->wl_bufbytes >= bp->b_bufsize);
   1138 	wl->wl_bufbytes -= bp->b_bufsize;
   1139 	KASSERT(wl->wl_bcount >= bp->b_bcount);
   1140 	wl->wl_bcount -= bp->b_bcount;
   1141 	KASSERT(wl->wl_bufcount > 0);
   1142 	wl->wl_bufcount--;
   1143 	KASSERT((wl->wl_bufcount == 0) == (wl->wl_bufbytes == 0));
   1144 	KASSERT((wl->wl_bufcount == 0) == (wl->wl_bcount == 0));
   1145 	LIST_REMOVE(bp, b_wapbllist);
   1146 
   1147 	bp->b_flags &= ~B_LOCKED;
   1148 }
   1149 
   1150 /* called from brelsel() in vfs_bio among other places */
   1151 void
   1152 wapbl_remove_buf(struct wapbl * wl, struct buf *bp)
   1153 {
   1154 
   1155 	mutex_enter(&wl->wl_mtx);
   1156 	wapbl_remove_buf_locked(wl, bp);
   1157 	mutex_exit(&wl->wl_mtx);
   1158 }
   1159 
   1160 void
   1161 wapbl_resize_buf(struct wapbl *wl, struct buf *bp, long oldsz, long oldcnt)
   1162 {
   1163 
   1164 	KASSERT(bp->b_cflags & BC_BUSY);
   1165 
   1166 	/*
   1167 	 * XXX: why does this depend on B_LOCKED?  otherwise the buf
   1168 	 * is not for a transaction?  if so, why is this called in the
   1169 	 * first place?
   1170 	 */
   1171 	if (bp->b_flags & B_LOCKED) {
   1172 		mutex_enter(&wl->wl_mtx);
   1173 		wl->wl_bufbytes += bp->b_bufsize - oldsz;
   1174 		wl->wl_bcount += bp->b_bcount - oldcnt;
   1175 		mutex_exit(&wl->wl_mtx);
   1176 	}
   1177 }
   1178 
   1179 #endif /* _KERNEL */
   1180 
   1181 /****************************************************************/
   1182 /* Some utility inlines */
   1183 
   1184 /*
   1185  * wapbl_space_used(avail, head, tail)
   1186  *
   1187  *	Number of bytes used in a circular queue of avail total bytes,
   1188  *	from tail to head.
   1189  */
   1190 static inline size_t
   1191 wapbl_space_used(size_t avail, off_t head, off_t tail)
   1192 {
   1193 
   1194 	if (tail == 0) {
   1195 		KASSERT(head == 0);
   1196 		return 0;
   1197 	}
   1198 	return ((head + (avail - 1) - tail) % avail) + 1;
   1199 }
   1200 
   1201 #ifdef _KERNEL
   1202 /*
   1203  * wapbl_advance(size, off, oldoff, delta)
   1204  *
   1205  *	Given a byte offset oldoff into a circular queue of size bytes
   1206  *	starting at off, return a new byte offset oldoff + delta into
   1207  *	the circular queue.
   1208  */
   1209 static inline off_t
   1210 wapbl_advance(size_t size, size_t off, off_t oldoff, size_t delta)
   1211 {
   1212 	off_t newoff;
   1213 
   1214 	/* Define acceptable ranges for inputs. */
   1215 	KASSERT(delta <= (size_t)size);
   1216 	KASSERT((oldoff == 0) || ((size_t)oldoff >= off));
   1217 	KASSERT(oldoff < (off_t)(size + off));
   1218 
   1219 	if ((oldoff == 0) && (delta != 0))
   1220 		newoff = off + delta;
   1221 	else if ((oldoff + delta) < (size + off))
   1222 		newoff = oldoff + delta;
   1223 	else
   1224 		newoff = (oldoff + delta) - size;
   1225 
   1226 	/* Note some interesting axioms */
   1227 	KASSERT((delta != 0) || (newoff == oldoff));
   1228 	KASSERT((delta == 0) || (newoff != 0));
   1229 	KASSERT((delta != (size)) || (newoff == oldoff));
   1230 
   1231 	/* Define acceptable ranges for output. */
   1232 	KASSERT((newoff == 0) || ((size_t)newoff >= off));
   1233 	KASSERT((size_t)newoff < (size + off));
   1234 	return newoff;
   1235 }
   1236 
   1237 /*
   1238  * wapbl_space_free(avail, head, tail)
   1239  *
   1240  *	Number of bytes free in a circular queue of avail total bytes,
   1241  *	in which everything from tail to head is used.
   1242  */
   1243 static inline size_t
   1244 wapbl_space_free(size_t avail, off_t head, off_t tail)
   1245 {
   1246 
   1247 	return avail - wapbl_space_used(avail, head, tail);
   1248 }
   1249 
   1250 /*
   1251  * wapbl_advance_head(size, off, delta, headp, tailp)
   1252  *
   1253  *	In a circular queue of size bytes starting at off, given the
   1254  *	old head and tail offsets *headp and *tailp, store the new head
   1255  *	and tail offsets in *headp and *tailp resulting from adding
   1256  *	delta bytes of data to the head.
   1257  */
   1258 static inline void
   1259 wapbl_advance_head(size_t size, size_t off, size_t delta, off_t *headp,
   1260 		   off_t *tailp)
   1261 {
   1262 	off_t head = *headp;
   1263 	off_t tail = *tailp;
   1264 
   1265 	KASSERT(delta <= wapbl_space_free(size, head, tail));
   1266 	head = wapbl_advance(size, off, head, delta);
   1267 	if ((tail == 0) && (head != 0))
   1268 		tail = off;
   1269 	*headp = head;
   1270 	*tailp = tail;
   1271 }
   1272 
   1273 /*
   1274  * wapbl_advance_tail(size, off, delta, headp, tailp)
   1275  *
   1276  *	In a circular queue of size bytes starting at off, given the
   1277  *	old head and tail offsets *headp and *tailp, store the new head
   1278  *	and tail offsets in *headp and *tailp resulting from removing
   1279  *	delta bytes of data from the tail.
   1280  */
   1281 static inline void
   1282 wapbl_advance_tail(size_t size, size_t off, size_t delta, off_t *headp,
   1283 		   off_t *tailp)
   1284 {
   1285 	off_t head = *headp;
   1286 	off_t tail = *tailp;
   1287 
   1288 	KASSERT(delta <= wapbl_space_used(size, head, tail));
   1289 	tail = wapbl_advance(size, off, tail, delta);
   1290 	if (head == tail) {
   1291 		head = tail = 0;
   1292 	}
   1293 	*headp = head;
   1294 	*tailp = tail;
   1295 }
   1296 
   1297 
   1298 /****************************************************************/
   1299 
   1300 /*
   1301  * wapbl_truncate(wl, minfree)
   1302  *
   1303  *	Wait until at least minfree bytes are available in the log.
   1304  *
   1305  *	If it was necessary to wait for writes to complete,
   1306  *	advance the circular queue tail to reflect the new write
   1307  *	completions and issue a write commit to the log.
   1308  *
   1309  *	=> Caller must hold wl->wl_rwlock writer lock.
   1310  */
   1311 static int
   1312 wapbl_truncate(struct wapbl *wl, size_t minfree)
   1313 {
   1314 	size_t delta;
   1315 	size_t avail;
   1316 	off_t head;
   1317 	off_t tail;
   1318 	int error = 0;
   1319 
   1320 	KASSERT(minfree <= (wl->wl_circ_size - wl->wl_reserved_bytes));
   1321 	KASSERT(rw_write_held(&wl->wl_rwlock));
   1322 
   1323 	mutex_enter(&wl->wl_mtx);
   1324 
   1325 	/*
   1326 	 * First check to see if we have to do a commit
   1327 	 * at all.
   1328 	 */
   1329 	avail = wapbl_space_free(wl->wl_circ_size, wl->wl_head, wl->wl_tail);
   1330 	if (minfree < avail) {
   1331 		mutex_exit(&wl->wl_mtx);
   1332 		return 0;
   1333 	}
   1334 	minfree -= avail;
   1335 	while ((wl->wl_error_count == 0) &&
   1336 	    (wl->wl_reclaimable_bytes < minfree)) {
   1337         	WAPBL_PRINTF(WAPBL_PRINT_TRUNCATE,
   1338                    ("wapbl_truncate: sleeping on %p wl=%p bytes=%zd "
   1339 		    "minfree=%zd\n",
   1340                     &wl->wl_reclaimable_bytes, wl, wl->wl_reclaimable_bytes,
   1341 		    minfree));
   1342 
   1343 		cv_wait(&wl->wl_reclaimable_cv, &wl->wl_mtx);
   1344 	}
   1345 	if (wl->wl_reclaimable_bytes < minfree) {
   1346 		KASSERT(wl->wl_error_count);
   1347 		/* XXX maybe get actual error from buffer instead someday? */
   1348 		error = EIO;
   1349 	}
   1350 	head = wl->wl_head;
   1351 	tail = wl->wl_tail;
   1352 	delta = wl->wl_reclaimable_bytes;
   1353 
   1354 	/* If all of of the entries are flushed, then be sure to keep
   1355 	 * the reserved bytes reserved.  Watch out for discarded transactions,
   1356 	 * which could leave more bytes reserved than are reclaimable.
   1357 	 */
   1358 	if (SIMPLEQ_EMPTY(&wl->wl_entries) &&
   1359 	    (delta >= wl->wl_reserved_bytes)) {
   1360 		delta -= wl->wl_reserved_bytes;
   1361 	}
   1362 	wapbl_advance_tail(wl->wl_circ_size, wl->wl_circ_off, delta, &head,
   1363 			   &tail);
   1364 	KDASSERT(wl->wl_reserved_bytes <=
   1365 		wapbl_space_used(wl->wl_circ_size, head, tail));
   1366 	mutex_exit(&wl->wl_mtx);
   1367 
   1368 	if (error)
   1369 		return error;
   1370 
   1371 	/*
   1372 	 * This is where head, tail and delta are unprotected
   1373 	 * from races against itself or flush.  This is ok since
   1374 	 * we only call this routine from inside flush itself.
   1375 	 *
   1376 	 * XXX: how can it race against itself when accessed only
   1377 	 * from behind the write-locked rwlock?
   1378 	 */
   1379 	error = wapbl_write_commit(wl, head, tail);
   1380 	if (error)
   1381 		return error;
   1382 
   1383 	wl->wl_head = head;
   1384 	wl->wl_tail = tail;
   1385 
   1386 	mutex_enter(&wl->wl_mtx);
   1387 	KASSERT(wl->wl_reclaimable_bytes >= delta);
   1388 	wl->wl_reclaimable_bytes -= delta;
   1389 	mutex_exit(&wl->wl_mtx);
   1390 	WAPBL_PRINTF(WAPBL_PRINT_TRUNCATE,
   1391 	    ("wapbl_truncate thread %d.%d truncating %zu bytes\n",
   1392 	    curproc->p_pid, curlwp->l_lid, delta));
   1393 
   1394 	return 0;
   1395 }
   1396 
   1397 /****************************************************************/
   1398 
   1399 void
   1400 wapbl_biodone(struct buf *bp)
   1401 {
   1402 	struct wapbl_entry *we = bp->b_private;
   1403 	struct wapbl *wl = we->we_wapbl;
   1404 #ifdef WAPBL_DEBUG_BUFBYTES
   1405 	const int bufsize = bp->b_bufsize;
   1406 #endif
   1407 
   1408 	/*
   1409 	 * Handle possible flushing of buffers after log has been
   1410 	 * decomissioned.
   1411 	 */
   1412 	if (!wl) {
   1413 		KASSERT(we->we_bufcount > 0);
   1414 		we->we_bufcount--;
   1415 #ifdef WAPBL_DEBUG_BUFBYTES
   1416 		KASSERT(we->we_unsynced_bufbytes >= bufsize);
   1417 		we->we_unsynced_bufbytes -= bufsize;
   1418 #endif
   1419 
   1420 		if (we->we_bufcount == 0) {
   1421 #ifdef WAPBL_DEBUG_BUFBYTES
   1422 			KASSERT(we->we_unsynced_bufbytes == 0);
   1423 #endif
   1424 			pool_put(&wapbl_entry_pool, we);
   1425 		}
   1426 
   1427 		brelse(bp, 0);
   1428 		return;
   1429 	}
   1430 
   1431 #ifdef ohbother
   1432 	KDASSERT(bp->b_oflags & BO_DONE);
   1433 	KDASSERT(!(bp->b_oflags & BO_DELWRI));
   1434 	KDASSERT(bp->b_flags & B_ASYNC);
   1435 	KDASSERT(bp->b_cflags & BC_BUSY);
   1436 	KDASSERT(!(bp->b_flags & B_LOCKED));
   1437 	KDASSERT(!(bp->b_flags & B_READ));
   1438 	KDASSERT(!(bp->b_cflags & BC_INVAL));
   1439 	KDASSERT(!(bp->b_cflags & BC_NOCACHE));
   1440 #endif
   1441 
   1442 	if (bp->b_error) {
   1443 		/*
   1444 		 * If an error occurs, it would be nice to leave the buffer
   1445 		 * as a delayed write on the LRU queue so that we can retry
   1446 		 * it later. But buffercache(9) can't handle dirty buffer
   1447 		 * reuse, so just mark the log permanently errored out.
   1448 		 */
   1449 		mutex_enter(&wl->wl_mtx);
   1450 		if (wl->wl_error_count == 0) {
   1451 			wl->wl_error_count++;
   1452 			cv_broadcast(&wl->wl_reclaimable_cv);
   1453 		}
   1454 		mutex_exit(&wl->wl_mtx);
   1455 	}
   1456 
   1457 	/*
   1458 	 * Release the buffer here. wapbl_flush() may wait for the
   1459 	 * log to become empty and we better unbusy the buffer before
   1460 	 * wapbl_flush() returns.
   1461 	 */
   1462 	brelse(bp, 0);
   1463 
   1464 	mutex_enter(&wl->wl_mtx);
   1465 
   1466 	KASSERT(we->we_bufcount > 0);
   1467 	we->we_bufcount--;
   1468 #ifdef WAPBL_DEBUG_BUFBYTES
   1469 	KASSERT(we->we_unsynced_bufbytes >= bufsize);
   1470 	we->we_unsynced_bufbytes -= bufsize;
   1471 	KASSERT(wl->wl_unsynced_bufbytes >= bufsize);
   1472 	wl->wl_unsynced_bufbytes -= bufsize;
   1473 #endif
   1474 
   1475 	/*
   1476 	 * If the current transaction can be reclaimed, start
   1477 	 * at the beginning and reclaim any consecutive reclaimable
   1478 	 * transactions.  If we successfully reclaim anything,
   1479 	 * then wakeup anyone waiting for the reclaim.
   1480 	 */
   1481 	if (we->we_bufcount == 0) {
   1482 		size_t delta = 0;
   1483 		int errcnt = 0;
   1484 #ifdef WAPBL_DEBUG_BUFBYTES
   1485 		KDASSERT(we->we_unsynced_bufbytes == 0);
   1486 #endif
   1487 		/*
   1488 		 * clear any posted error, since the buffer it came from
   1489 		 * has successfully flushed by now
   1490 		 */
   1491 		while ((we = SIMPLEQ_FIRST(&wl->wl_entries)) &&
   1492 		       (we->we_bufcount == 0)) {
   1493 			delta += we->we_reclaimable_bytes;
   1494 			if (we->we_error)
   1495 				errcnt++;
   1496 			SIMPLEQ_REMOVE_HEAD(&wl->wl_entries, we_entries);
   1497 			pool_put(&wapbl_entry_pool, we);
   1498 		}
   1499 
   1500 		if (delta) {
   1501 			wl->wl_reclaimable_bytes += delta;
   1502 			KASSERT(wl->wl_error_count >= errcnt);
   1503 			wl->wl_error_count -= errcnt;
   1504 			cv_broadcast(&wl->wl_reclaimable_cv);
   1505 		}
   1506 	}
   1507 
   1508 	mutex_exit(&wl->wl_mtx);
   1509 }
   1510 
   1511 /*
   1512  * wapbl_flush(wl, wait)
   1513  *
   1514  *	Flush pending block writes, deallocations, and inodes from
   1515  *	the current transaction in memory to the log on disk:
   1516  *
   1517  *	1. Call the file system's wl_flush callback to flush any
   1518  *	   per-file-system pending updates.
   1519  *	2. Wait for enough space in the log for the current transaction.
   1520  *	3. Synchronously write the new log records, advancing the
   1521  *	   circular queue head.
   1522  *	4. Issue the pending block writes asynchronously, now that they
   1523  *	   are recorded in the log and can be replayed after crash.
   1524  *	5. If wait is true, wait for all writes to complete and for the
   1525  *	   log to become empty.
   1526  *
   1527  *	On failure, call the file system's wl_flush_abort callback.
   1528  */
   1529 int
   1530 wapbl_flush(struct wapbl *wl, int waitfor)
   1531 {
   1532 	struct buf *bp;
   1533 	struct wapbl_entry *we;
   1534 	off_t off;
   1535 	off_t head;
   1536 	off_t tail;
   1537 	size_t delta = 0;
   1538 	size_t flushsize;
   1539 	size_t reserved;
   1540 	int error = 0;
   1541 
   1542 	/*
   1543 	 * Do a quick check to see if a full flush can be skipped
   1544 	 * This assumes that the flush callback does not need to be called
   1545 	 * unless there are other outstanding bufs.
   1546 	 */
   1547 	if (!waitfor) {
   1548 		size_t nbufs;
   1549 		mutex_enter(&wl->wl_mtx);	/* XXX need mutex here to
   1550 						   protect the KASSERTS */
   1551 		nbufs = wl->wl_bufcount;
   1552 		KASSERT((wl->wl_bufcount == 0) == (wl->wl_bufbytes == 0));
   1553 		KASSERT((wl->wl_bufcount == 0) == (wl->wl_bcount == 0));
   1554 		mutex_exit(&wl->wl_mtx);
   1555 		if (nbufs == 0)
   1556 			return 0;
   1557 	}
   1558 
   1559 	/*
   1560 	 * XXX we may consider using LK_UPGRADE here
   1561 	 * if we want to call flush from inside a transaction
   1562 	 */
   1563 	rw_enter(&wl->wl_rwlock, RW_WRITER);
   1564 	wl->wl_flush(wl->wl_mount, SIMPLEQ_FIRST(&wl->wl_dealloclist));
   1565 
   1566 	/*
   1567 	 * Now that we are exclusively locked and the file system has
   1568 	 * issued any deferred block writes for this transaction, check
   1569 	 * whether there are any blocks to write to the log.  If not,
   1570 	 * skip waiting for space or writing any log entries.
   1571 	 *
   1572 	 * XXX Shouldn't this also check wl_dealloccnt and
   1573 	 * wl_inohashcnt?  Perhaps wl_dealloccnt doesn't matter if the
   1574 	 * file system didn't produce any blocks as a consequence of
   1575 	 * it, but the same does not seem to be so of wl_inohashcnt.
   1576 	 */
   1577 	if (wl->wl_bufcount == 0) {
   1578 		goto wait_out;
   1579 	}
   1580 
   1581 #if 0
   1582 	WAPBL_PRINTF(WAPBL_PRINT_FLUSH,
   1583 		     ("wapbl_flush thread %d.%d flushing entries with "
   1584 		      "bufcount=%zu bufbytes=%zu\n",
   1585 		      curproc->p_pid, curlwp->l_lid, wl->wl_bufcount,
   1586 		      wl->wl_bufbytes));
   1587 #endif
   1588 
   1589 	/* Calculate amount of space needed to flush */
   1590 	flushsize = wapbl_transaction_len(wl);
   1591 	if (wapbl_verbose_commit) {
   1592 		struct timespec ts;
   1593 		getnanotime(&ts);
   1594 		printf("%s: %lld.%09ld this transaction = %zu bytes\n",
   1595 		    __func__, (long long)ts.tv_sec,
   1596 		    (long)ts.tv_nsec, flushsize);
   1597 	}
   1598 
   1599 	if (flushsize > (wl->wl_circ_size - wl->wl_reserved_bytes)) {
   1600 		/*
   1601 		 * XXX this could be handled more gracefully, perhaps place
   1602 		 * only a partial transaction in the log and allow the
   1603 		 * remaining to flush without the protection of the journal.
   1604 		 */
   1605 		panic("wapbl_flush: current transaction too big to flush");
   1606 	}
   1607 
   1608 	error = wapbl_truncate(wl, flushsize);
   1609 	if (error)
   1610 		goto out;
   1611 
   1612 	off = wl->wl_head;
   1613 	KASSERT((off == 0) || (off >= wl->wl_circ_off));
   1614 	KASSERT((off == 0) || (off < wl->wl_circ_off + wl->wl_circ_size));
   1615 	error = wapbl_write_blocks(wl, &off);
   1616 	if (error)
   1617 		goto out;
   1618 	error = wapbl_write_revocations(wl, &off);
   1619 	if (error)
   1620 		goto out;
   1621 	error = wapbl_write_inodes(wl, &off);
   1622 	if (error)
   1623 		goto out;
   1624 
   1625 	reserved = 0;
   1626 	if (wl->wl_inohashcnt)
   1627 		reserved = wapbl_transaction_inodes_len(wl);
   1628 
   1629 	head = wl->wl_head;
   1630 	tail = wl->wl_tail;
   1631 
   1632 	wapbl_advance_head(wl->wl_circ_size, wl->wl_circ_off, flushsize,
   1633 	    &head, &tail);
   1634 
   1635 	KASSERTMSG(head == off,
   1636 	    "lost head! head=%"PRIdMAX" tail=%" PRIdMAX
   1637 	    " off=%"PRIdMAX" flush=%zu",
   1638 	    (intmax_t)head, (intmax_t)tail, (intmax_t)off,
   1639 	    flushsize);
   1640 
   1641 	/* Opportunistically move the tail forward if we can */
   1642 	mutex_enter(&wl->wl_mtx);
   1643 	delta = wl->wl_reclaimable_bytes;
   1644 	mutex_exit(&wl->wl_mtx);
   1645 	wapbl_advance_tail(wl->wl_circ_size, wl->wl_circ_off, delta,
   1646 	    &head, &tail);
   1647 
   1648 	error = wapbl_write_commit(wl, head, tail);
   1649 	if (error)
   1650 		goto out;
   1651 
   1652 	we = pool_get(&wapbl_entry_pool, PR_WAITOK);
   1653 
   1654 #ifdef WAPBL_DEBUG_BUFBYTES
   1655 	WAPBL_PRINTF(WAPBL_PRINT_FLUSH,
   1656 		("wapbl_flush: thread %d.%d head+=%zu tail+=%zu used=%zu"
   1657 		 " unsynced=%zu"
   1658 		 "\n\tbufcount=%zu bufbytes=%zu bcount=%zu deallocs=%d "
   1659 		 "inodes=%d\n",
   1660 		 curproc->p_pid, curlwp->l_lid, flushsize, delta,
   1661 		 wapbl_space_used(wl->wl_circ_size, head, tail),
   1662 		 wl->wl_unsynced_bufbytes, wl->wl_bufcount,
   1663 		 wl->wl_bufbytes, wl->wl_bcount, wl->wl_dealloccnt,
   1664 		 wl->wl_inohashcnt));
   1665 #else
   1666 	WAPBL_PRINTF(WAPBL_PRINT_FLUSH,
   1667 		("wapbl_flush: thread %d.%d head+=%zu tail+=%zu used=%zu"
   1668 		 "\n\tbufcount=%zu bufbytes=%zu bcount=%zu deallocs=%d "
   1669 		 "inodes=%d\n",
   1670 		 curproc->p_pid, curlwp->l_lid, flushsize, delta,
   1671 		 wapbl_space_used(wl->wl_circ_size, head, tail),
   1672 		 wl->wl_bufcount, wl->wl_bufbytes, wl->wl_bcount,
   1673 		 wl->wl_dealloccnt, wl->wl_inohashcnt));
   1674 #endif
   1675 
   1676 
   1677 	mutex_enter(&bufcache_lock);
   1678 	mutex_enter(&wl->wl_mtx);
   1679 
   1680 	wl->wl_reserved_bytes = reserved;
   1681 	wl->wl_head = head;
   1682 	wl->wl_tail = tail;
   1683 	KASSERT(wl->wl_reclaimable_bytes >= delta);
   1684 	wl->wl_reclaimable_bytes -= delta;
   1685 	KDASSERT(wl->wl_dealloccnt == 0);
   1686 #ifdef WAPBL_DEBUG_BUFBYTES
   1687 	wl->wl_unsynced_bufbytes += wl->wl_bufbytes;
   1688 #endif
   1689 
   1690 	we->we_wapbl = wl;
   1691 	we->we_bufcount = wl->wl_bufcount;
   1692 #ifdef WAPBL_DEBUG_BUFBYTES
   1693 	we->we_unsynced_bufbytes = wl->wl_bufbytes;
   1694 #endif
   1695 	we->we_reclaimable_bytes = flushsize;
   1696 	we->we_error = 0;
   1697 	SIMPLEQ_INSERT_TAIL(&wl->wl_entries, we, we_entries);
   1698 
   1699 	/*
   1700 	 * this flushes bufs in reverse order than they were queued
   1701 	 * it shouldn't matter, but if we care we could use TAILQ instead.
   1702 	 * XXX Note they will get put on the lru queue when they flush
   1703 	 * so we might actually want to change this to preserve order.
   1704 	 */
   1705 	while ((bp = LIST_FIRST(&wl->wl_bufs)) != NULL) {
   1706 		if (bbusy(bp, 0, 0, &wl->wl_mtx)) {
   1707 			continue;
   1708 		}
   1709 		bp->b_iodone = wapbl_biodone;
   1710 		bp->b_private = we;
   1711 		bremfree(bp);
   1712 		wapbl_remove_buf_locked(wl, bp);
   1713 		mutex_exit(&wl->wl_mtx);
   1714 		mutex_exit(&bufcache_lock);
   1715 		bawrite(bp);
   1716 		mutex_enter(&bufcache_lock);
   1717 		mutex_enter(&wl->wl_mtx);
   1718 	}
   1719 	mutex_exit(&wl->wl_mtx);
   1720 	mutex_exit(&bufcache_lock);
   1721 
   1722 #if 0
   1723 	WAPBL_PRINTF(WAPBL_PRINT_FLUSH,
   1724 		     ("wapbl_flush thread %d.%d done flushing entries...\n",
   1725 		     curproc->p_pid, curlwp->l_lid));
   1726 #endif
   1727 
   1728  wait_out:
   1729 
   1730 	/*
   1731 	 * If the waitfor flag is set, don't return until everything is
   1732 	 * fully flushed and the on disk log is empty.
   1733 	 */
   1734 	if (waitfor) {
   1735 		error = wapbl_truncate(wl, wl->wl_circ_size -
   1736 			wl->wl_reserved_bytes);
   1737 	}
   1738 
   1739  out:
   1740 	if (error) {
   1741 		wl->wl_flush_abort(wl->wl_mount,
   1742 		    SIMPLEQ_FIRST(&wl->wl_dealloclist));
   1743 	}
   1744 
   1745 #ifdef WAPBL_DEBUG_PRINT
   1746 	if (error) {
   1747 		pid_t pid = -1;
   1748 		lwpid_t lid = -1;
   1749 		if (curproc)
   1750 			pid = curproc->p_pid;
   1751 		if (curlwp)
   1752 			lid = curlwp->l_lid;
   1753 		mutex_enter(&wl->wl_mtx);
   1754 #ifdef WAPBL_DEBUG_BUFBYTES
   1755 		WAPBL_PRINTF(WAPBL_PRINT_ERROR,
   1756 		    ("wapbl_flush: thread %d.%d aborted flush: "
   1757 		    "error = %d\n"
   1758 		    "\tbufcount=%zu bufbytes=%zu bcount=%zu "
   1759 		    "deallocs=%d inodes=%d\n"
   1760 		    "\terrcnt = %d, reclaimable=%zu reserved=%zu "
   1761 		    "unsynced=%zu\n",
   1762 		    pid, lid, error, wl->wl_bufcount,
   1763 		    wl->wl_bufbytes, wl->wl_bcount,
   1764 		    wl->wl_dealloccnt, wl->wl_inohashcnt,
   1765 		    wl->wl_error_count, wl->wl_reclaimable_bytes,
   1766 		    wl->wl_reserved_bytes, wl->wl_unsynced_bufbytes));
   1767 		SIMPLEQ_FOREACH(we, &wl->wl_entries, we_entries) {
   1768 			WAPBL_PRINTF(WAPBL_PRINT_ERROR,
   1769 			    ("\tentry: bufcount = %zu, reclaimable = %zu, "
   1770 			     "error = %d, unsynced = %zu\n",
   1771 			     we->we_bufcount, we->we_reclaimable_bytes,
   1772 			     we->we_error, we->we_unsynced_bufbytes));
   1773 		}
   1774 #else
   1775 		WAPBL_PRINTF(WAPBL_PRINT_ERROR,
   1776 		    ("wapbl_flush: thread %d.%d aborted flush: "
   1777 		     "error = %d\n"
   1778 		     "\tbufcount=%zu bufbytes=%zu bcount=%zu "
   1779 		     "deallocs=%d inodes=%d\n"
   1780 		     "\terrcnt = %d, reclaimable=%zu reserved=%zu\n",
   1781 		     pid, lid, error, wl->wl_bufcount,
   1782 		     wl->wl_bufbytes, wl->wl_bcount,
   1783 		     wl->wl_dealloccnt, wl->wl_inohashcnt,
   1784 		     wl->wl_error_count, wl->wl_reclaimable_bytes,
   1785 		     wl->wl_reserved_bytes));
   1786 		SIMPLEQ_FOREACH(we, &wl->wl_entries, we_entries) {
   1787 			WAPBL_PRINTF(WAPBL_PRINT_ERROR,
   1788 			    ("\tentry: bufcount = %zu, reclaimable = %zu, "
   1789 			     "error = %d\n", we->we_bufcount,
   1790 			     we->we_reclaimable_bytes, we->we_error));
   1791 		}
   1792 #endif
   1793 		mutex_exit(&wl->wl_mtx);
   1794 	}
   1795 #endif
   1796 
   1797 	rw_exit(&wl->wl_rwlock);
   1798 	return error;
   1799 }
   1800 
   1801 /****************************************************************/
   1802 
   1803 void
   1804 wapbl_jlock_assert(struct wapbl *wl)
   1805 {
   1806 
   1807 	KASSERT(rw_lock_held(&wl->wl_rwlock));
   1808 }
   1809 
   1810 void
   1811 wapbl_junlock_assert(struct wapbl *wl)
   1812 {
   1813 
   1814 	KASSERT(!rw_write_held(&wl->wl_rwlock));
   1815 }
   1816 
   1817 /****************************************************************/
   1818 
   1819 /* locks missing */
   1820 void
   1821 wapbl_print(struct wapbl *wl,
   1822 		int full,
   1823 		void (*pr)(const char *, ...))
   1824 {
   1825 	struct buf *bp;
   1826 	struct wapbl_entry *we;
   1827 	(*pr)("wapbl %p", wl);
   1828 	(*pr)("\nlogvp = %p, devvp = %p, logpbn = %"PRId64"\n",
   1829 	      wl->wl_logvp, wl->wl_devvp, wl->wl_logpbn);
   1830 	(*pr)("circ = %zu, header = %zu, head = %"PRIdMAX" tail = %"PRIdMAX"\n",
   1831 	      wl->wl_circ_size, wl->wl_circ_off,
   1832 	      (intmax_t)wl->wl_head, (intmax_t)wl->wl_tail);
   1833 	(*pr)("fs_dev_bshift = %d, log_dev_bshift = %d\n",
   1834 	      wl->wl_log_dev_bshift, wl->wl_fs_dev_bshift);
   1835 #ifdef WAPBL_DEBUG_BUFBYTES
   1836 	(*pr)("bufcount = %zu, bufbytes = %zu bcount = %zu reclaimable = %zu "
   1837 	      "reserved = %zu errcnt = %d unsynced = %zu\n",
   1838 	      wl->wl_bufcount, wl->wl_bufbytes, wl->wl_bcount,
   1839 	      wl->wl_reclaimable_bytes, wl->wl_reserved_bytes,
   1840 				wl->wl_error_count, wl->wl_unsynced_bufbytes);
   1841 #else
   1842 	(*pr)("bufcount = %zu, bufbytes = %zu bcount = %zu reclaimable = %zu "
   1843 	      "reserved = %zu errcnt = %d\n", wl->wl_bufcount, wl->wl_bufbytes,
   1844 	      wl->wl_bcount, wl->wl_reclaimable_bytes, wl->wl_reserved_bytes,
   1845 				wl->wl_error_count);
   1846 #endif
   1847 	(*pr)("\tdealloccnt = %d, dealloclim = %d\n",
   1848 	      wl->wl_dealloccnt, wl->wl_dealloclim);
   1849 	(*pr)("\tinohashcnt = %d, inohashmask = 0x%08x\n",
   1850 	      wl->wl_inohashcnt, wl->wl_inohashmask);
   1851 	(*pr)("entries:\n");
   1852 	SIMPLEQ_FOREACH(we, &wl->wl_entries, we_entries) {
   1853 #ifdef WAPBL_DEBUG_BUFBYTES
   1854 		(*pr)("\tbufcount = %zu, reclaimable = %zu, error = %d, "
   1855 		      "unsynced = %zu\n",
   1856 		      we->we_bufcount, we->we_reclaimable_bytes,
   1857 		      we->we_error, we->we_unsynced_bufbytes);
   1858 #else
   1859 		(*pr)("\tbufcount = %zu, reclaimable = %zu, error = %d\n",
   1860 		      we->we_bufcount, we->we_reclaimable_bytes, we->we_error);
   1861 #endif
   1862 	}
   1863 	if (full) {
   1864 		int cnt = 0;
   1865 		(*pr)("bufs =");
   1866 		LIST_FOREACH(bp, &wl->wl_bufs, b_wapbllist) {
   1867 			if (!LIST_NEXT(bp, b_wapbllist)) {
   1868 				(*pr)(" %p", bp);
   1869 			} else if ((++cnt % 6) == 0) {
   1870 				(*pr)(" %p,\n\t", bp);
   1871 			} else {
   1872 				(*pr)(" %p,", bp);
   1873 			}
   1874 		}
   1875 		(*pr)("\n");
   1876 
   1877 		(*pr)("dealloced blks = ");
   1878 		{
   1879 			struct wapbl_dealloc *wd;
   1880 			cnt = 0;
   1881 			SIMPLEQ_FOREACH(wd, &wl->wl_dealloclist, wd_entries) {
   1882 				(*pr)(" %"PRId64":%d,",
   1883 				      wd->wd_blkno,
   1884 				      wd->wd_len);
   1885 				if ((++cnt % 4) == 0) {
   1886 					(*pr)("\n\t");
   1887 				}
   1888 			}
   1889 		}
   1890 		(*pr)("\n");
   1891 
   1892 		(*pr)("registered inodes = ");
   1893 		{
   1894 			int i;
   1895 			cnt = 0;
   1896 			for (i = 0; i <= wl->wl_inohashmask; i++) {
   1897 				struct wapbl_ino_head *wih;
   1898 				struct wapbl_ino *wi;
   1899 
   1900 				wih = &wl->wl_inohash[i];
   1901 				LIST_FOREACH(wi, wih, wi_hash) {
   1902 					if (wi->wi_ino == 0)
   1903 						continue;
   1904 					(*pr)(" %"PRIu64"/0%06"PRIo32",",
   1905 					    wi->wi_ino, wi->wi_mode);
   1906 					if ((++cnt % 4) == 0) {
   1907 						(*pr)("\n\t");
   1908 					}
   1909 				}
   1910 			}
   1911 			(*pr)("\n");
   1912 		}
   1913 	}
   1914 }
   1915 
   1916 #if defined(WAPBL_DEBUG) || defined(DDB)
   1917 void
   1918 wapbl_dump(struct wapbl *wl)
   1919 {
   1920 #if defined(WAPBL_DEBUG)
   1921 	if (!wl)
   1922 		wl = wapbl_debug_wl;
   1923 #endif
   1924 	if (!wl)
   1925 		return;
   1926 	wapbl_print(wl, 1, printf);
   1927 }
   1928 #endif
   1929 
   1930 /****************************************************************/
   1931 
   1932 int
   1933 wapbl_register_deallocation(struct wapbl *wl, daddr_t blk, int len, bool force)
   1934 {
   1935 	struct wapbl_dealloc *wd;
   1936 	int error = 0;
   1937 
   1938 	wapbl_jlock_assert(wl);
   1939 
   1940 	mutex_enter(&wl->wl_mtx);
   1941 
   1942 	if (__predict_false(wl->wl_dealloccnt >= wl->wl_dealloclim)) {
   1943 		if (!force) {
   1944 			error = EAGAIN;
   1945 			goto out;
   1946 		}
   1947 
   1948 		/*
   1949 		 * Forced registration can only be used when:
   1950 		 * 1) the caller can't cope with failure
   1951 		 * 2) the path can be triggered only bounded, small
   1952 		 *    times per transaction
   1953 		 * If this is not fullfilled, and the path would be triggered
   1954 		 * many times, this could overflow maximum transaction size
   1955 		 * and panic later.
   1956 		 */
   1957 		printf("%s: forced dealloc registration over limit: %d >= %d\n",
   1958 			wl->wl_mount->mnt_stat.f_mntonname,
   1959 			wl->wl_dealloccnt, wl->wl_dealloclim);
   1960 	}
   1961 
   1962 	wl->wl_dealloccnt++;
   1963 	mutex_exit(&wl->wl_mtx);
   1964 
   1965 	wd = pool_get(&wapbl_dealloc_pool, PR_WAITOK);
   1966 	wd->wd_blkno = blk;
   1967 	wd->wd_len = len;
   1968 
   1969 	mutex_enter(&wl->wl_mtx);
   1970 	SIMPLEQ_INSERT_TAIL(&wl->wl_dealloclist, wd, wd_entries);
   1971 
   1972  out:
   1973 	mutex_exit(&wl->wl_mtx);
   1974 
   1975 	WAPBL_PRINTF(WAPBL_PRINT_ALLOC,
   1976 	    ("wapbl_register_deallocation: blk=%"PRId64" len=%d error=%d\n",
   1977 	    blk, len, error));
   1978 
   1979 	return error;
   1980 }
   1981 
   1982 /****************************************************************/
   1983 
   1984 static void
   1985 wapbl_inodetrk_init(struct wapbl *wl, u_int size)
   1986 {
   1987 
   1988 	wl->wl_inohash = hashinit(size, HASH_LIST, true, &wl->wl_inohashmask);
   1989 	if (atomic_inc_uint_nv(&wapbl_ino_pool_refcount) == 1) {
   1990 		pool_init(&wapbl_ino_pool, sizeof(struct wapbl_ino), 0, 0, 0,
   1991 		    "wapblinopl", &pool_allocator_nointr, IPL_NONE);
   1992 	}
   1993 }
   1994 
   1995 static void
   1996 wapbl_inodetrk_free(struct wapbl *wl)
   1997 {
   1998 
   1999 	/* XXX this KASSERT needs locking/mutex analysis */
   2000 	KASSERT(wl->wl_inohashcnt == 0);
   2001 	hashdone(wl->wl_inohash, HASH_LIST, wl->wl_inohashmask);
   2002 	if (atomic_dec_uint_nv(&wapbl_ino_pool_refcount) == 0) {
   2003 		pool_destroy(&wapbl_ino_pool);
   2004 	}
   2005 }
   2006 
   2007 static struct wapbl_ino *
   2008 wapbl_inodetrk_get(struct wapbl *wl, ino_t ino)
   2009 {
   2010 	struct wapbl_ino_head *wih;
   2011 	struct wapbl_ino *wi;
   2012 
   2013 	KASSERT(mutex_owned(&wl->wl_mtx));
   2014 
   2015 	wih = &wl->wl_inohash[ino & wl->wl_inohashmask];
   2016 	LIST_FOREACH(wi, wih, wi_hash) {
   2017 		if (ino == wi->wi_ino)
   2018 			return wi;
   2019 	}
   2020 	return 0;
   2021 }
   2022 
   2023 void
   2024 wapbl_register_inode(struct wapbl *wl, ino_t ino, mode_t mode)
   2025 {
   2026 	struct wapbl_ino_head *wih;
   2027 	struct wapbl_ino *wi;
   2028 
   2029 	wi = pool_get(&wapbl_ino_pool, PR_WAITOK);
   2030 
   2031 	mutex_enter(&wl->wl_mtx);
   2032 	if (wapbl_inodetrk_get(wl, ino) == NULL) {
   2033 		wi->wi_ino = ino;
   2034 		wi->wi_mode = mode;
   2035 		wih = &wl->wl_inohash[ino & wl->wl_inohashmask];
   2036 		LIST_INSERT_HEAD(wih, wi, wi_hash);
   2037 		wl->wl_inohashcnt++;
   2038 		WAPBL_PRINTF(WAPBL_PRINT_INODE,
   2039 		    ("wapbl_register_inode: ino=%"PRId64"\n", ino));
   2040 		mutex_exit(&wl->wl_mtx);
   2041 	} else {
   2042 		mutex_exit(&wl->wl_mtx);
   2043 		pool_put(&wapbl_ino_pool, wi);
   2044 	}
   2045 }
   2046 
   2047 void
   2048 wapbl_unregister_inode(struct wapbl *wl, ino_t ino, mode_t mode)
   2049 {
   2050 	struct wapbl_ino *wi;
   2051 
   2052 	mutex_enter(&wl->wl_mtx);
   2053 	wi = wapbl_inodetrk_get(wl, ino);
   2054 	if (wi) {
   2055 		WAPBL_PRINTF(WAPBL_PRINT_INODE,
   2056 		    ("wapbl_unregister_inode: ino=%"PRId64"\n", ino));
   2057 		KASSERT(wl->wl_inohashcnt > 0);
   2058 		wl->wl_inohashcnt--;
   2059 		LIST_REMOVE(wi, wi_hash);
   2060 		mutex_exit(&wl->wl_mtx);
   2061 
   2062 		pool_put(&wapbl_ino_pool, wi);
   2063 	} else {
   2064 		mutex_exit(&wl->wl_mtx);
   2065 	}
   2066 }
   2067 
   2068 /****************************************************************/
   2069 
   2070 /*
   2071  * wapbl_transaction_inodes_len(wl)
   2072  *
   2073  *	Calculate the number of bytes required for inode registration
   2074  *	log records in wl.
   2075  */
   2076 static inline size_t
   2077 wapbl_transaction_inodes_len(struct wapbl *wl)
   2078 {
   2079 	int blocklen = 1<<wl->wl_log_dev_bshift;
   2080 	int iph;
   2081 
   2082 	/* Calculate number of inodes described in a inodelist header */
   2083 	iph = (blocklen - offsetof(struct wapbl_wc_inodelist, wc_inodes)) /
   2084 	    sizeof(((struct wapbl_wc_inodelist *)0)->wc_inodes[0]);
   2085 
   2086 	KASSERT(iph > 0);
   2087 
   2088 	return MAX(1, howmany(wl->wl_inohashcnt, iph)) * blocklen;
   2089 }
   2090 
   2091 
   2092 /*
   2093  * wapbl_transaction_len(wl)
   2094  *
   2095  *	Calculate number of bytes required for all log records in wl.
   2096  */
   2097 static size_t
   2098 wapbl_transaction_len(struct wapbl *wl)
   2099 {
   2100 	int blocklen = 1<<wl->wl_log_dev_bshift;
   2101 	size_t len;
   2102 
   2103 	/* Calculate number of blocks described in a blocklist header */
   2104 	len = wl->wl_bcount;
   2105 	len += howmany(wl->wl_bufcount, wl->wl_brperjblock) * blocklen;
   2106 	len += howmany(wl->wl_dealloccnt, wl->wl_brperjblock) * blocklen;
   2107 	len += wapbl_transaction_inodes_len(wl);
   2108 
   2109 	return len;
   2110 }
   2111 
   2112 /*
   2113  * wapbl_cache_sync(wl, msg)
   2114  *
   2115  *	Issue DIOCCACHESYNC to wl->wl_devvp.
   2116  *
   2117  *	If sysctl(vfs.wapbl.verbose_commit) >= 2, print a message
   2118  *	including msg about the duration of the cache sync.
   2119  */
   2120 static int
   2121 wapbl_cache_sync(struct wapbl *wl, const char *msg)
   2122 {
   2123 	const bool verbose = wapbl_verbose_commit >= 2;
   2124 	struct bintime start_time;
   2125 	int force = 1;
   2126 	int error;
   2127 
   2128 	if (!wapbl_flush_disk_cache) {
   2129 		return 0;
   2130 	}
   2131 	if (verbose) {
   2132 		bintime(&start_time);
   2133 	}
   2134 	error = VOP_IOCTL(wl->wl_devvp, DIOCCACHESYNC, &force,
   2135 	    FWRITE, FSCRED);
   2136 	if (error) {
   2137 		WAPBL_PRINTF(WAPBL_PRINT_ERROR,
   2138 		    ("wapbl_cache_sync: DIOCCACHESYNC on dev 0x%jx "
   2139 		    "returned %d\n", (uintmax_t)wl->wl_devvp->v_rdev, error));
   2140 	}
   2141 	if (verbose) {
   2142 		struct bintime d;
   2143 		struct timespec ts;
   2144 
   2145 		bintime(&d);
   2146 		bintime_sub(&d, &start_time);
   2147 		bintime2timespec(&d, &ts);
   2148 		printf("wapbl_cache_sync: %s: dev 0x%jx %ju.%09lu\n",
   2149 		    msg, (uintmax_t)wl->wl_devvp->v_rdev,
   2150 		    (uintmax_t)ts.tv_sec, ts.tv_nsec);
   2151 	}
   2152 	return error;
   2153 }
   2154 
   2155 /*
   2156  * wapbl_write_commit(wl, head, tail)
   2157  *
   2158  *	Issue a disk cache sync to wait for all pending writes to the
   2159  *	log to complete, and then synchronously commit the current
   2160  *	circular queue head and tail to the log, in the next of two
   2161  *	locations for commit headers on disk.
   2162  *
   2163  *	Increment the generation number.  If the generation number
   2164  *	rolls over to zero, then a subsequent commit would appear to
   2165  *	have an older generation than this one -- in that case, issue a
   2166  *	duplicate commit to avoid this.
   2167  *
   2168  *	=> Caller must have exclusive access to wl, either by holding
   2169  *	wl->wl_rwlock for writer or by being wapbl_start before anyone
   2170  *	else has seen wl.
   2171  */
   2172 static int
   2173 wapbl_write_commit(struct wapbl *wl, off_t head, off_t tail)
   2174 {
   2175 	struct wapbl_wc_header *wc = wl->wl_wc_header;
   2176 	struct timespec ts;
   2177 	int error;
   2178 	daddr_t pbn;
   2179 
   2180 	error = wapbl_buffered_flush(wl);
   2181 	if (error)
   2182 		return error;
   2183 	/*
   2184 	 * flush disk cache to ensure that blocks we've written are actually
   2185 	 * written to the stable storage before the commit header.
   2186 	 *
   2187 	 * XXX Calc checksum here, instead we do this for now
   2188 	 */
   2189 	wapbl_cache_sync(wl, "1");
   2190 
   2191 	wc->wc_head = head;
   2192 	wc->wc_tail = tail;
   2193 	wc->wc_checksum = 0;
   2194 	wc->wc_version = 1;
   2195 	getnanotime(&ts);
   2196 	wc->wc_time = ts.tv_sec;
   2197 	wc->wc_timensec = ts.tv_nsec;
   2198 
   2199 	WAPBL_PRINTF(WAPBL_PRINT_WRITE,
   2200 	    ("wapbl_write_commit: head = %"PRIdMAX "tail = %"PRIdMAX"\n",
   2201 	    (intmax_t)head, (intmax_t)tail));
   2202 
   2203 	/*
   2204 	 * write the commit header.
   2205 	 *
   2206 	 * XXX if generation will rollover, then first zero
   2207 	 * over second commit header before trying to write both headers.
   2208 	 */
   2209 
   2210 	pbn = wl->wl_logpbn + (wc->wc_generation % 2);
   2211 #ifdef _KERNEL
   2212 	pbn = btodb(pbn << wc->wc_log_dev_bshift);
   2213 #endif
   2214 	error = wapbl_buffered_write(wc, wc->wc_len, wl, pbn);
   2215 	if (error)
   2216 		return error;
   2217 	error = wapbl_buffered_flush(wl);
   2218 	if (error)
   2219 		return error;
   2220 
   2221 	/*
   2222 	 * flush disk cache to ensure that the commit header is actually
   2223 	 * written before meta data blocks.
   2224 	 */
   2225 	wapbl_cache_sync(wl, "2");
   2226 
   2227 	/*
   2228 	 * If the generation number was zero, write it out a second time.
   2229 	 * This handles initialization and generation number rollover
   2230 	 */
   2231 	if (wc->wc_generation++ == 0) {
   2232 		error = wapbl_write_commit(wl, head, tail);
   2233 		/*
   2234 		 * This panic should be able to be removed if we do the
   2235 		 * zero'ing mentioned above, and we are certain to roll
   2236 		 * back generation number on failure.
   2237 		 */
   2238 		if (error)
   2239 			panic("wapbl_write_commit: error writing duplicate "
   2240 			      "log header: %d", error);
   2241 	}
   2242 	return 0;
   2243 }
   2244 
   2245 /*
   2246  * wapbl_write_blocks(wl, offp)
   2247  *
   2248  *	Write all pending physical blocks in the current transaction
   2249  *	from wapbl_add_buf to the log on disk, adding to the circular
   2250  *	queue head at byte offset *offp, and returning the new head's
   2251  *	byte offset in *offp.
   2252  */
   2253 static int
   2254 wapbl_write_blocks(struct wapbl *wl, off_t *offp)
   2255 {
   2256 	struct wapbl_wc_blocklist *wc =
   2257 	    (struct wapbl_wc_blocklist *)wl->wl_wc_scratch;
   2258 	int blocklen = 1<<wl->wl_log_dev_bshift;
   2259 	struct buf *bp;
   2260 	off_t off = *offp;
   2261 	int error;
   2262 	size_t padding;
   2263 
   2264 	KASSERT(rw_write_held(&wl->wl_rwlock));
   2265 
   2266 	bp = LIST_FIRST(&wl->wl_bufs);
   2267 
   2268 	while (bp) {
   2269 		int cnt;
   2270 		struct buf *obp = bp;
   2271 
   2272 		KASSERT(bp->b_flags & B_LOCKED);
   2273 
   2274 		wc->wc_type = WAPBL_WC_BLOCKS;
   2275 		wc->wc_len = blocklen;
   2276 		wc->wc_blkcount = 0;
   2277 		while (bp && (wc->wc_blkcount < wl->wl_brperjblock)) {
   2278 			/*
   2279 			 * Make sure all the physical block numbers are up to
   2280 			 * date.  If this is not always true on a given
   2281 			 * filesystem, then VOP_BMAP must be called.  We
   2282 			 * could call VOP_BMAP here, or else in the filesystem
   2283 			 * specific flush callback, although neither of those
   2284 			 * solutions allow us to take the vnode lock.  If a
   2285 			 * filesystem requires that we must take the vnode lock
   2286 			 * to call VOP_BMAP, then we can probably do it in
   2287 			 * bwrite when the vnode lock should already be held
   2288 			 * by the invoking code.
   2289 			 */
   2290 			KASSERT((bp->b_vp->v_type == VBLK) ||
   2291 				 (bp->b_blkno != bp->b_lblkno));
   2292 			KASSERT(bp->b_blkno > 0);
   2293 
   2294 			wc->wc_blocks[wc->wc_blkcount].wc_daddr = bp->b_blkno;
   2295 			wc->wc_blocks[wc->wc_blkcount].wc_dlen = bp->b_bcount;
   2296 			wc->wc_len += bp->b_bcount;
   2297 			wc->wc_blkcount++;
   2298 			bp = LIST_NEXT(bp, b_wapbllist);
   2299 		}
   2300 		if (wc->wc_len % blocklen != 0) {
   2301 			padding = blocklen - wc->wc_len % blocklen;
   2302 			wc->wc_len += padding;
   2303 		} else {
   2304 			padding = 0;
   2305 		}
   2306 
   2307 		WAPBL_PRINTF(WAPBL_PRINT_WRITE,
   2308 		    ("wapbl_write_blocks: len = %u (padding %zu) off = %"PRIdMAX"\n",
   2309 		    wc->wc_len, padding, (intmax_t)off));
   2310 
   2311 		error = wapbl_circ_write(wl, wc, blocklen, &off);
   2312 		if (error)
   2313 			return error;
   2314 		bp = obp;
   2315 		cnt = 0;
   2316 		while (bp && (cnt++ < wl->wl_brperjblock)) {
   2317 			error = wapbl_circ_write(wl, bp->b_data,
   2318 			    bp->b_bcount, &off);
   2319 			if (error)
   2320 				return error;
   2321 			bp = LIST_NEXT(bp, b_wapbllist);
   2322 		}
   2323 		if (padding) {
   2324 			void *zero;
   2325 
   2326 			zero = wapbl_alloc(padding);
   2327 			memset(zero, 0, padding);
   2328 			error = wapbl_circ_write(wl, zero, padding, &off);
   2329 			wapbl_free(zero, padding);
   2330 			if (error)
   2331 				return error;
   2332 		}
   2333 	}
   2334 	*offp = off;
   2335 	return 0;
   2336 }
   2337 
   2338 /*
   2339  * wapbl_write_revocations(wl, offp)
   2340  *
   2341  *	Write all pending deallocations in the current transaction from
   2342  *	wapbl_register_deallocation to the log on disk, adding to the
   2343  *	circular queue's head at byte offset *offp, and returning the
   2344  *	new head's byte offset in *offp.
   2345  */
   2346 static int
   2347 wapbl_write_revocations(struct wapbl *wl, off_t *offp)
   2348 {
   2349 	struct wapbl_wc_blocklist *wc =
   2350 	    (struct wapbl_wc_blocklist *)wl->wl_wc_scratch;
   2351 	struct wapbl_dealloc *wd, *lwd;
   2352 	int blocklen = 1<<wl->wl_log_dev_bshift;
   2353 	off_t off = *offp;
   2354 	int error;
   2355 
   2356 	if (wl->wl_dealloccnt == 0)
   2357 		return 0;
   2358 
   2359 	while ((wd = SIMPLEQ_FIRST(&wl->wl_dealloclist)) != NULL) {
   2360 		wc->wc_type = WAPBL_WC_REVOCATIONS;
   2361 		wc->wc_len = blocklen;
   2362 		wc->wc_blkcount = 0;
   2363 		while (wd && (wc->wc_blkcount < wl->wl_brperjblock)) {
   2364 			wc->wc_blocks[wc->wc_blkcount].wc_daddr =
   2365 			    wd->wd_blkno;
   2366 			wc->wc_blocks[wc->wc_blkcount].wc_dlen =
   2367 			    wd->wd_len;
   2368 			wc->wc_blkcount++;
   2369 
   2370 			wd = SIMPLEQ_NEXT(wd, wd_entries);
   2371 		}
   2372 		WAPBL_PRINTF(WAPBL_PRINT_WRITE,
   2373 		    ("wapbl_write_revocations: len = %u off = %"PRIdMAX"\n",
   2374 		    wc->wc_len, (intmax_t)off));
   2375 		error = wapbl_circ_write(wl, wc, blocklen, &off);
   2376 		if (error)
   2377 			return error;
   2378 
   2379 		/* free all successfully written deallocs */
   2380 		lwd = wd;
   2381 		while ((wd = SIMPLEQ_FIRST(&wl->wl_dealloclist)) != NULL) {
   2382 			if (wd == lwd)
   2383 				break;
   2384 			SIMPLEQ_REMOVE_HEAD(&wl->wl_dealloclist, wd_entries);
   2385 			pool_put(&wapbl_dealloc_pool, wd);
   2386 			wl->wl_dealloccnt--;
   2387 		}
   2388 	}
   2389 	*offp = off;
   2390 	return 0;
   2391 }
   2392 
   2393 /*
   2394  * wapbl_write_inodes(wl, offp)
   2395  *
   2396  *	Write all pending inode allocations in the current transaction
   2397  *	from wapbl_register_inode to the log on disk, adding to the
   2398  *	circular queue's head at byte offset *offp and returning the
   2399  *	new head's byte offset in *offp.
   2400  */
   2401 static int
   2402 wapbl_write_inodes(struct wapbl *wl, off_t *offp)
   2403 {
   2404 	struct wapbl_wc_inodelist *wc =
   2405 	    (struct wapbl_wc_inodelist *)wl->wl_wc_scratch;
   2406 	int i;
   2407 	int blocklen = 1 << wl->wl_log_dev_bshift;
   2408 	off_t off = *offp;
   2409 	int error;
   2410 
   2411 	struct wapbl_ino_head *wih;
   2412 	struct wapbl_ino *wi;
   2413 	int iph;
   2414 
   2415 	iph = (blocklen - offsetof(struct wapbl_wc_inodelist, wc_inodes)) /
   2416 	    sizeof(((struct wapbl_wc_inodelist *)0)->wc_inodes[0]);
   2417 
   2418 	i = 0;
   2419 	wih = &wl->wl_inohash[0];
   2420 	wi = 0;
   2421 	do {
   2422 		wc->wc_type = WAPBL_WC_INODES;
   2423 		wc->wc_len = blocklen;
   2424 		wc->wc_inocnt = 0;
   2425 		wc->wc_clear = (i == 0);
   2426 		while ((i < wl->wl_inohashcnt) && (wc->wc_inocnt < iph)) {
   2427 			while (!wi) {
   2428 				KASSERT((wih - &wl->wl_inohash[0])
   2429 				    <= wl->wl_inohashmask);
   2430 				wi = LIST_FIRST(wih++);
   2431 			}
   2432 			wc->wc_inodes[wc->wc_inocnt].wc_inumber = wi->wi_ino;
   2433 			wc->wc_inodes[wc->wc_inocnt].wc_imode = wi->wi_mode;
   2434 			wc->wc_inocnt++;
   2435 			i++;
   2436 			wi = LIST_NEXT(wi, wi_hash);
   2437 		}
   2438 		WAPBL_PRINTF(WAPBL_PRINT_WRITE,
   2439 		    ("wapbl_write_inodes: len = %u off = %"PRIdMAX"\n",
   2440 		    wc->wc_len, (intmax_t)off));
   2441 		error = wapbl_circ_write(wl, wc, blocklen, &off);
   2442 		if (error)
   2443 			return error;
   2444 	} while (i < wl->wl_inohashcnt);
   2445 
   2446 	*offp = off;
   2447 	return 0;
   2448 }
   2449 
   2450 #endif /* _KERNEL */
   2451 
   2452 /****************************************************************/
   2453 
   2454 struct wapbl_blk {
   2455 	LIST_ENTRY(wapbl_blk) wb_hash;
   2456 	daddr_t wb_blk;
   2457 	off_t wb_off; /* Offset of this block in the log */
   2458 };
   2459 #define	WAPBL_BLKPOOL_MIN 83
   2460 
   2461 static void
   2462 wapbl_blkhash_init(struct wapbl_replay *wr, u_int size)
   2463 {
   2464 	if (size < WAPBL_BLKPOOL_MIN)
   2465 		size = WAPBL_BLKPOOL_MIN;
   2466 	KASSERT(wr->wr_blkhash == 0);
   2467 #ifdef _KERNEL
   2468 	wr->wr_blkhash = hashinit(size, HASH_LIST, true, &wr->wr_blkhashmask);
   2469 #else /* ! _KERNEL */
   2470 	/* Manually implement hashinit */
   2471 	{
   2472 		unsigned long i, hashsize;
   2473 		for (hashsize = 1; hashsize < size; hashsize <<= 1)
   2474 			continue;
   2475 		wr->wr_blkhash = wapbl_alloc(hashsize * sizeof(*wr->wr_blkhash));
   2476 		for (i = 0; i < hashsize; i++)
   2477 			LIST_INIT(&wr->wr_blkhash[i]);
   2478 		wr->wr_blkhashmask = hashsize - 1;
   2479 	}
   2480 #endif /* ! _KERNEL */
   2481 }
   2482 
   2483 static void
   2484 wapbl_blkhash_free(struct wapbl_replay *wr)
   2485 {
   2486 	KASSERT(wr->wr_blkhashcnt == 0);
   2487 #ifdef _KERNEL
   2488 	hashdone(wr->wr_blkhash, HASH_LIST, wr->wr_blkhashmask);
   2489 #else /* ! _KERNEL */
   2490 	wapbl_free(wr->wr_blkhash,
   2491 	    (wr->wr_blkhashmask + 1) * sizeof(*wr->wr_blkhash));
   2492 #endif /* ! _KERNEL */
   2493 }
   2494 
   2495 static struct wapbl_blk *
   2496 wapbl_blkhash_get(struct wapbl_replay *wr, daddr_t blk)
   2497 {
   2498 	struct wapbl_blk_head *wbh;
   2499 	struct wapbl_blk *wb;
   2500 	wbh = &wr->wr_blkhash[blk & wr->wr_blkhashmask];
   2501 	LIST_FOREACH(wb, wbh, wb_hash) {
   2502 		if (blk == wb->wb_blk)
   2503 			return wb;
   2504 	}
   2505 	return 0;
   2506 }
   2507 
   2508 static void
   2509 wapbl_blkhash_ins(struct wapbl_replay *wr, daddr_t blk, off_t off)
   2510 {
   2511 	struct wapbl_blk_head *wbh;
   2512 	struct wapbl_blk *wb;
   2513 	wb = wapbl_blkhash_get(wr, blk);
   2514 	if (wb) {
   2515 		KASSERT(wb->wb_blk == blk);
   2516 		wb->wb_off = off;
   2517 	} else {
   2518 		wb = wapbl_alloc(sizeof(*wb));
   2519 		wb->wb_blk = blk;
   2520 		wb->wb_off = off;
   2521 		wbh = &wr->wr_blkhash[blk & wr->wr_blkhashmask];
   2522 		LIST_INSERT_HEAD(wbh, wb, wb_hash);
   2523 		wr->wr_blkhashcnt++;
   2524 	}
   2525 }
   2526 
   2527 static void
   2528 wapbl_blkhash_rem(struct wapbl_replay *wr, daddr_t blk)
   2529 {
   2530 	struct wapbl_blk *wb = wapbl_blkhash_get(wr, blk);
   2531 	if (wb) {
   2532 		KASSERT(wr->wr_blkhashcnt > 0);
   2533 		wr->wr_blkhashcnt--;
   2534 		LIST_REMOVE(wb, wb_hash);
   2535 		wapbl_free(wb, sizeof(*wb));
   2536 	}
   2537 }
   2538 
   2539 static void
   2540 wapbl_blkhash_clear(struct wapbl_replay *wr)
   2541 {
   2542 	unsigned long i;
   2543 	for (i = 0; i <= wr->wr_blkhashmask; i++) {
   2544 		struct wapbl_blk *wb;
   2545 
   2546 		while ((wb = LIST_FIRST(&wr->wr_blkhash[i]))) {
   2547 			KASSERT(wr->wr_blkhashcnt > 0);
   2548 			wr->wr_blkhashcnt--;
   2549 			LIST_REMOVE(wb, wb_hash);
   2550 			wapbl_free(wb, sizeof(*wb));
   2551 		}
   2552 	}
   2553 	KASSERT(wr->wr_blkhashcnt == 0);
   2554 }
   2555 
   2556 /****************************************************************/
   2557 
   2558 /*
   2559  * wapbl_circ_read(wr, data, len, offp)
   2560  *
   2561  *	Read len bytes into data from the circular queue of wr,
   2562  *	starting at the linear byte offset *offp, and returning the new
   2563  *	linear byte offset in *offp.
   2564  *
   2565  *	If the starting linear byte offset precedes wr->wr_circ_off,
   2566  *	the read instead begins at wr->wr_circ_off.  XXX WTF?  This
   2567  *	should be a KASSERT, not a conditional.
   2568  */
   2569 static int
   2570 wapbl_circ_read(struct wapbl_replay *wr, void *data, size_t len, off_t *offp)
   2571 {
   2572 	size_t slen;
   2573 	off_t off = *offp;
   2574 	int error;
   2575 	daddr_t pbn;
   2576 
   2577 	KASSERT(((len >> wr->wr_log_dev_bshift) <<
   2578 	    wr->wr_log_dev_bshift) == len);
   2579 
   2580 	if (off < wr->wr_circ_off)
   2581 		off = wr->wr_circ_off;
   2582 	slen = wr->wr_circ_off + wr->wr_circ_size - off;
   2583 	if (slen < len) {
   2584 		pbn = wr->wr_logpbn + (off >> wr->wr_log_dev_bshift);
   2585 #ifdef _KERNEL
   2586 		pbn = btodb(pbn << wr->wr_log_dev_bshift);
   2587 #endif
   2588 		error = wapbl_read(data, slen, wr->wr_devvp, pbn);
   2589 		if (error)
   2590 			return error;
   2591 		data = (uint8_t *)data + slen;
   2592 		len -= slen;
   2593 		off = wr->wr_circ_off;
   2594 	}
   2595 	pbn = wr->wr_logpbn + (off >> wr->wr_log_dev_bshift);
   2596 #ifdef _KERNEL
   2597 	pbn = btodb(pbn << wr->wr_log_dev_bshift);
   2598 #endif
   2599 	error = wapbl_read(data, len, wr->wr_devvp, pbn);
   2600 	if (error)
   2601 		return error;
   2602 	off += len;
   2603 	if (off >= wr->wr_circ_off + wr->wr_circ_size)
   2604 		off = wr->wr_circ_off;
   2605 	*offp = off;
   2606 	return 0;
   2607 }
   2608 
   2609 /*
   2610  * wapbl_circ_advance(wr, len, offp)
   2611  *
   2612  *	Compute the linear byte offset of the circular queue of wr that
   2613  *	is len bytes past *offp, and store it in *offp.
   2614  *
   2615  *	This is as if wapbl_circ_read, but without actually reading
   2616  *	anything.
   2617  *
   2618  *	If the starting linear byte offset precedes wr->wr_circ_off, it
   2619  *	is taken to be wr->wr_circ_off instead.  XXX WTF?  This should
   2620  *	be a KASSERT, not a conditional.
   2621  */
   2622 static void
   2623 wapbl_circ_advance(struct wapbl_replay *wr, size_t len, off_t *offp)
   2624 {
   2625 	size_t slen;
   2626 	off_t off = *offp;
   2627 
   2628 	KASSERT(((len >> wr->wr_log_dev_bshift) <<
   2629 	    wr->wr_log_dev_bshift) == len);
   2630 
   2631 	if (off < wr->wr_circ_off)
   2632 		off = wr->wr_circ_off;
   2633 	slen = wr->wr_circ_off + wr->wr_circ_size - off;
   2634 	if (slen < len) {
   2635 		len -= slen;
   2636 		off = wr->wr_circ_off;
   2637 	}
   2638 	off += len;
   2639 	if (off >= wr->wr_circ_off + wr->wr_circ_size)
   2640 		off = wr->wr_circ_off;
   2641 	*offp = off;
   2642 }
   2643 
   2644 /****************************************************************/
   2645 
   2646 int
   2647 wapbl_replay_start(struct wapbl_replay **wrp, struct vnode *vp,
   2648 	daddr_t off, size_t count, size_t blksize)
   2649 {
   2650 	struct wapbl_replay *wr;
   2651 	int error;
   2652 	struct vnode *devvp;
   2653 	daddr_t logpbn;
   2654 	uint8_t *scratch;
   2655 	struct wapbl_wc_header *wch;
   2656 	struct wapbl_wc_header *wch2;
   2657 	/* Use this until we read the actual log header */
   2658 	int log_dev_bshift = ilog2(blksize);
   2659 	size_t used;
   2660 	daddr_t pbn;
   2661 
   2662 	WAPBL_PRINTF(WAPBL_PRINT_REPLAY,
   2663 	    ("wapbl_replay_start: vp=%p off=%"PRId64 " count=%zu blksize=%zu\n",
   2664 	    vp, off, count, blksize));
   2665 
   2666 	if (off < 0)
   2667 		return EINVAL;
   2668 
   2669 	if (blksize < DEV_BSIZE)
   2670 		return EINVAL;
   2671 	if (blksize % DEV_BSIZE)
   2672 		return EINVAL;
   2673 
   2674 #ifdef _KERNEL
   2675 #if 0
   2676 	/* XXX vp->v_size isn't reliably set for VBLK devices,
   2677 	 * especially root.  However, we might still want to verify
   2678 	 * that the full load is readable */
   2679 	if ((off + count) * blksize > vp->v_size)
   2680 		return EINVAL;
   2681 #endif
   2682 	if ((error = VOP_BMAP(vp, off, &devvp, &logpbn, 0)) != 0) {
   2683 		return error;
   2684 	}
   2685 #else /* ! _KERNEL */
   2686 	devvp = vp;
   2687 	logpbn = off;
   2688 #endif /* ! _KERNEL */
   2689 
   2690 	scratch = wapbl_alloc(MAXBSIZE);
   2691 
   2692 	pbn = logpbn;
   2693 #ifdef _KERNEL
   2694 	pbn = btodb(pbn << log_dev_bshift);
   2695 #endif
   2696 	error = wapbl_read(scratch, 2<<log_dev_bshift, devvp, pbn);
   2697 	if (error)
   2698 		goto errout;
   2699 
   2700 	wch = (struct wapbl_wc_header *)scratch;
   2701 	wch2 =
   2702 	    (struct wapbl_wc_header *)(scratch + (1<<log_dev_bshift));
   2703 	/* XXX verify checksums and magic numbers */
   2704 	if (wch->wc_type != WAPBL_WC_HEADER) {
   2705 		printf("Unrecognized wapbl magic: 0x%08x\n", wch->wc_type);
   2706 		error = EFTYPE;
   2707 		goto errout;
   2708 	}
   2709 
   2710 	if (wch2->wc_generation > wch->wc_generation)
   2711 		wch = wch2;
   2712 
   2713 	wr = wapbl_calloc(1, sizeof(*wr));
   2714 
   2715 	wr->wr_logvp = vp;
   2716 	wr->wr_devvp = devvp;
   2717 	wr->wr_logpbn = logpbn;
   2718 
   2719 	wr->wr_scratch = scratch;
   2720 
   2721 	wr->wr_log_dev_bshift = wch->wc_log_dev_bshift;
   2722 	wr->wr_fs_dev_bshift = wch->wc_fs_dev_bshift;
   2723 	wr->wr_circ_off = wch->wc_circ_off;
   2724 	wr->wr_circ_size = wch->wc_circ_size;
   2725 	wr->wr_generation = wch->wc_generation;
   2726 
   2727 	used = wapbl_space_used(wch->wc_circ_size, wch->wc_head, wch->wc_tail);
   2728 
   2729 	WAPBL_PRINTF(WAPBL_PRINT_REPLAY,
   2730 	    ("wapbl_replay: head=%"PRId64" tail=%"PRId64" off=%"PRId64
   2731 	    " len=%"PRId64" used=%zu\n",
   2732 	    wch->wc_head, wch->wc_tail, wch->wc_circ_off,
   2733 	    wch->wc_circ_size, used));
   2734 
   2735 	wapbl_blkhash_init(wr, (used >> wch->wc_fs_dev_bshift));
   2736 
   2737 	error = wapbl_replay_process(wr, wch->wc_head, wch->wc_tail);
   2738 	if (error) {
   2739 		wapbl_replay_stop(wr);
   2740 		wapbl_replay_free(wr);
   2741 		return error;
   2742 	}
   2743 
   2744 	*wrp = wr;
   2745 	return 0;
   2746 
   2747  errout:
   2748 	wapbl_free(scratch, MAXBSIZE);
   2749 	return error;
   2750 }
   2751 
   2752 void
   2753 wapbl_replay_stop(struct wapbl_replay *wr)
   2754 {
   2755 
   2756 	if (!wapbl_replay_isopen(wr))
   2757 		return;
   2758 
   2759 	WAPBL_PRINTF(WAPBL_PRINT_REPLAY, ("wapbl_replay_stop called\n"));
   2760 
   2761 	wapbl_free(wr->wr_scratch, MAXBSIZE);
   2762 	wr->wr_scratch = NULL;
   2763 
   2764 	wr->wr_logvp = NULL;
   2765 
   2766 	wapbl_blkhash_clear(wr);
   2767 	wapbl_blkhash_free(wr);
   2768 }
   2769 
   2770 void
   2771 wapbl_replay_free(struct wapbl_replay *wr)
   2772 {
   2773 
   2774 	KDASSERT(!wapbl_replay_isopen(wr));
   2775 
   2776 	if (wr->wr_inodes)
   2777 		wapbl_free(wr->wr_inodes,
   2778 		    wr->wr_inodescnt * sizeof(wr->wr_inodes[0]));
   2779 	wapbl_free(wr, sizeof(*wr));
   2780 }
   2781 
   2782 #ifdef _KERNEL
   2783 int
   2784 wapbl_replay_isopen1(struct wapbl_replay *wr)
   2785 {
   2786 
   2787 	return wapbl_replay_isopen(wr);
   2788 }
   2789 #endif
   2790 
   2791 /*
   2792  * calculate the disk address for the i'th block in the wc_blockblist
   2793  * offset by j blocks of size blen.
   2794  *
   2795  * wc_daddr is always a kernel disk address in DEV_BSIZE units that
   2796  * was written to the journal.
   2797  *
   2798  * The kernel needs that address plus the offset in DEV_BSIZE units.
   2799  *
   2800  * Userland needs that address plus the offset in blen units.
   2801  *
   2802  */
   2803 static daddr_t
   2804 wapbl_block_daddr(struct wapbl_wc_blocklist *wc, int i, int j, int blen)
   2805 {
   2806 	daddr_t pbn;
   2807 
   2808 #ifdef _KERNEL
   2809 	pbn = wc->wc_blocks[i].wc_daddr + btodb(j * blen);
   2810 #else
   2811 	pbn = dbtob(wc->wc_blocks[i].wc_daddr) / blen + j;
   2812 #endif
   2813 
   2814 	return pbn;
   2815 }
   2816 
   2817 static void
   2818 wapbl_replay_process_blocks(struct wapbl_replay *wr, off_t *offp)
   2819 {
   2820 	struct wapbl_wc_blocklist *wc =
   2821 	    (struct wapbl_wc_blocklist *)wr->wr_scratch;
   2822 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   2823 	int i, j, n;
   2824 
   2825 	for (i = 0; i < wc->wc_blkcount; i++) {
   2826 		/*
   2827 		 * Enter each physical block into the hashtable independently.
   2828 		 */
   2829 		n = wc->wc_blocks[i].wc_dlen >> wr->wr_fs_dev_bshift;
   2830 		for (j = 0; j < n; j++) {
   2831 			wapbl_blkhash_ins(wr, wapbl_block_daddr(wc, i, j, fsblklen),
   2832 			    *offp);
   2833 			wapbl_circ_advance(wr, fsblklen, offp);
   2834 		}
   2835 	}
   2836 }
   2837 
   2838 static void
   2839 wapbl_replay_process_revocations(struct wapbl_replay *wr)
   2840 {
   2841 	struct wapbl_wc_blocklist *wc =
   2842 	    (struct wapbl_wc_blocklist *)wr->wr_scratch;
   2843 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   2844 	int i, j, n;
   2845 
   2846 	for (i = 0; i < wc->wc_blkcount; i++) {
   2847 		/*
   2848 		 * Remove any blocks found from the hashtable.
   2849 		 */
   2850 		n = wc->wc_blocks[i].wc_dlen >> wr->wr_fs_dev_bshift;
   2851 		for (j = 0; j < n; j++)
   2852 			wapbl_blkhash_rem(wr, wapbl_block_daddr(wc, i, j, fsblklen));
   2853 	}
   2854 }
   2855 
   2856 static void
   2857 wapbl_replay_process_inodes(struct wapbl_replay *wr, off_t oldoff, off_t newoff)
   2858 {
   2859 	struct wapbl_wc_inodelist *wc =
   2860 	    (struct wapbl_wc_inodelist *)wr->wr_scratch;
   2861 	void *new_inodes;
   2862 	const size_t oldsize = wr->wr_inodescnt * sizeof(wr->wr_inodes[0]);
   2863 
   2864 	KASSERT(sizeof(wr->wr_inodes[0]) == sizeof(wc->wc_inodes[0]));
   2865 
   2866 	/*
   2867 	 * Keep track of where we found this so location won't be
   2868 	 * overwritten.
   2869 	 */
   2870 	if (wc->wc_clear) {
   2871 		wr->wr_inodestail = oldoff;
   2872 		wr->wr_inodescnt = 0;
   2873 		if (wr->wr_inodes != NULL) {
   2874 			wapbl_free(wr->wr_inodes, oldsize);
   2875 			wr->wr_inodes = NULL;
   2876 		}
   2877 	}
   2878 	wr->wr_inodeshead = newoff;
   2879 	if (wc->wc_inocnt == 0)
   2880 		return;
   2881 
   2882 	new_inodes = wapbl_alloc((wr->wr_inodescnt + wc->wc_inocnt) *
   2883 	    sizeof(wr->wr_inodes[0]));
   2884 	if (wr->wr_inodes != NULL) {
   2885 		memcpy(new_inodes, wr->wr_inodes, oldsize);
   2886 		wapbl_free(wr->wr_inodes, oldsize);
   2887 	}
   2888 	wr->wr_inodes = new_inodes;
   2889 	memcpy(&wr->wr_inodes[wr->wr_inodescnt], wc->wc_inodes,
   2890 	    wc->wc_inocnt * sizeof(wr->wr_inodes[0]));
   2891 	wr->wr_inodescnt += wc->wc_inocnt;
   2892 }
   2893 
   2894 static int
   2895 wapbl_replay_process(struct wapbl_replay *wr, off_t head, off_t tail)
   2896 {
   2897 	off_t off;
   2898 	int error;
   2899 
   2900 	int logblklen = 1 << wr->wr_log_dev_bshift;
   2901 
   2902 	wapbl_blkhash_clear(wr);
   2903 
   2904 	off = tail;
   2905 	while (off != head) {
   2906 		struct wapbl_wc_null *wcn;
   2907 		off_t saveoff = off;
   2908 		error = wapbl_circ_read(wr, wr->wr_scratch, logblklen, &off);
   2909 		if (error)
   2910 			goto errout;
   2911 		wcn = (struct wapbl_wc_null *)wr->wr_scratch;
   2912 		switch (wcn->wc_type) {
   2913 		case WAPBL_WC_BLOCKS:
   2914 			wapbl_replay_process_blocks(wr, &off);
   2915 			break;
   2916 
   2917 		case WAPBL_WC_REVOCATIONS:
   2918 			wapbl_replay_process_revocations(wr);
   2919 			break;
   2920 
   2921 		case WAPBL_WC_INODES:
   2922 			wapbl_replay_process_inodes(wr, saveoff, off);
   2923 			break;
   2924 
   2925 		default:
   2926 			printf("Unrecognized wapbl type: 0x%08x\n",
   2927 			       wcn->wc_type);
   2928  			error = EFTYPE;
   2929 			goto errout;
   2930 		}
   2931 		wapbl_circ_advance(wr, wcn->wc_len, &saveoff);
   2932 		if (off != saveoff) {
   2933 			printf("wapbl_replay: corrupted records\n");
   2934 			error = EFTYPE;
   2935 			goto errout;
   2936 		}
   2937 	}
   2938 	return 0;
   2939 
   2940  errout:
   2941 	wapbl_blkhash_clear(wr);
   2942 	return error;
   2943 }
   2944 
   2945 #if 0
   2946 int
   2947 wapbl_replay_verify(struct wapbl_replay *wr, struct vnode *fsdevvp)
   2948 {
   2949 	off_t off;
   2950 	int mismatchcnt = 0;
   2951 	int logblklen = 1 << wr->wr_log_dev_bshift;
   2952 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   2953 	void *scratch1 = wapbl_alloc(MAXBSIZE);
   2954 	void *scratch2 = wapbl_alloc(MAXBSIZE);
   2955 	int error = 0;
   2956 
   2957 	KDASSERT(wapbl_replay_isopen(wr));
   2958 
   2959 	off = wch->wc_tail;
   2960 	while (off != wch->wc_head) {
   2961 		struct wapbl_wc_null *wcn;
   2962 #ifdef DEBUG
   2963 		off_t saveoff = off;
   2964 #endif
   2965 		error = wapbl_circ_read(wr, wr->wr_scratch, logblklen, &off);
   2966 		if (error)
   2967 			goto out;
   2968 		wcn = (struct wapbl_wc_null *)wr->wr_scratch;
   2969 		switch (wcn->wc_type) {
   2970 		case WAPBL_WC_BLOCKS:
   2971 			{
   2972 				struct wapbl_wc_blocklist *wc =
   2973 				    (struct wapbl_wc_blocklist *)wr->wr_scratch;
   2974 				int i;
   2975 				for (i = 0; i < wc->wc_blkcount; i++) {
   2976 					int foundcnt = 0;
   2977 					int dirtycnt = 0;
   2978 					int j, n;
   2979 					/*
   2980 					 * Check each physical block into the
   2981 					 * hashtable independently
   2982 					 */
   2983 					n = wc->wc_blocks[i].wc_dlen >>
   2984 					    wch->wc_fs_dev_bshift;
   2985 					for (j = 0; j < n; j++) {
   2986 						struct wapbl_blk *wb =
   2987 						   wapbl_blkhash_get(wr,
   2988 						   wapbl_block_daddr(wc, i, j, fsblklen));
   2989 						if (wb && (wb->wb_off == off)) {
   2990 							foundcnt++;
   2991 							error =
   2992 							    wapbl_circ_read(wr,
   2993 							    scratch1, fsblklen,
   2994 							    &off);
   2995 							if (error)
   2996 								goto out;
   2997 							error =
   2998 							    wapbl_read(scratch2,
   2999 							    fsblklen, fsdevvp,
   3000 							    wb->wb_blk);
   3001 							if (error)
   3002 								goto out;
   3003 							if (memcmp(scratch1,
   3004 								   scratch2,
   3005 								   fsblklen)) {
   3006 								printf(
   3007 		"wapbl_verify: mismatch block %"PRId64" at off %"PRIdMAX"\n",
   3008 		wb->wb_blk, (intmax_t)off);
   3009 								dirtycnt++;
   3010 								mismatchcnt++;
   3011 							}
   3012 						} else {
   3013 							wapbl_circ_advance(wr,
   3014 							    fsblklen, &off);
   3015 						}
   3016 					}
   3017 #if 0
   3018 					/*
   3019 					 * If all of the blocks in an entry
   3020 					 * are clean, then remove all of its
   3021 					 * blocks from the hashtable since they
   3022 					 * never will need replay.
   3023 					 */
   3024 					if ((foundcnt != 0) &&
   3025 					    (dirtycnt == 0)) {
   3026 						off = saveoff;
   3027 						wapbl_circ_advance(wr,
   3028 						    logblklen, &off);
   3029 						for (j = 0; j < n; j++) {
   3030 							struct wapbl_blk *wb =
   3031 							   wapbl_blkhash_get(wr,
   3032 							   wapbl_block_daddr(wc, i, j, fsblklen));
   3033 							if (wb &&
   3034 							  (wb->wb_off == off)) {
   3035 								wapbl_blkhash_rem(wr, wb->wb_blk);
   3036 							}
   3037 							wapbl_circ_advance(wr,
   3038 							    fsblklen, &off);
   3039 						}
   3040 					}
   3041 #endif
   3042 				}
   3043 			}
   3044 			break;
   3045 		case WAPBL_WC_REVOCATIONS:
   3046 		case WAPBL_WC_INODES:
   3047 			break;
   3048 		default:
   3049 			KASSERT(0);
   3050 		}
   3051 #ifdef DEBUG
   3052 		wapbl_circ_advance(wr, wcn->wc_len, &saveoff);
   3053 		KASSERT(off == saveoff);
   3054 #endif
   3055 	}
   3056  out:
   3057 	wapbl_free(scratch1, MAXBSIZE);
   3058 	wapbl_free(scratch2, MAXBSIZE);
   3059 	if (!error && mismatchcnt)
   3060 		error = EFTYPE;
   3061 	return error;
   3062 }
   3063 #endif
   3064 
   3065 int
   3066 wapbl_replay_write(struct wapbl_replay *wr, struct vnode *fsdevvp)
   3067 {
   3068 	struct wapbl_blk *wb;
   3069 	size_t i;
   3070 	off_t off;
   3071 	void *scratch;
   3072 	int error = 0;
   3073 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   3074 
   3075 	KDASSERT(wapbl_replay_isopen(wr));
   3076 
   3077 	scratch = wapbl_alloc(MAXBSIZE);
   3078 
   3079 	for (i = 0; i <= wr->wr_blkhashmask; ++i) {
   3080 		LIST_FOREACH(wb, &wr->wr_blkhash[i], wb_hash) {
   3081 			off = wb->wb_off;
   3082 			error = wapbl_circ_read(wr, scratch, fsblklen, &off);
   3083 			if (error)
   3084 				break;
   3085 			error = wapbl_write(scratch, fsblklen, fsdevvp,
   3086 			    wb->wb_blk);
   3087 			if (error)
   3088 				break;
   3089 		}
   3090 	}
   3091 
   3092 	wapbl_free(scratch, MAXBSIZE);
   3093 	return error;
   3094 }
   3095 
   3096 int
   3097 wapbl_replay_can_read(struct wapbl_replay *wr, daddr_t blk, long len)
   3098 {
   3099 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   3100 
   3101 	KDASSERT(wapbl_replay_isopen(wr));
   3102 	KASSERT((len % fsblklen) == 0);
   3103 
   3104 	while (len != 0) {
   3105 		struct wapbl_blk *wb = wapbl_blkhash_get(wr, blk);
   3106 		if (wb)
   3107 			return 1;
   3108 		len -= fsblklen;
   3109 	}
   3110 	return 0;
   3111 }
   3112 
   3113 int
   3114 wapbl_replay_read(struct wapbl_replay *wr, void *data, daddr_t blk, long len)
   3115 {
   3116 	int fsblklen = 1 << wr->wr_fs_dev_bshift;
   3117 
   3118 	KDASSERT(wapbl_replay_isopen(wr));
   3119 
   3120 	KASSERT((len % fsblklen) == 0);
   3121 
   3122 	while (len != 0) {
   3123 		struct wapbl_blk *wb = wapbl_blkhash_get(wr, blk);
   3124 		if (wb) {
   3125 			off_t off = wb->wb_off;
   3126 			int error;
   3127 			error = wapbl_circ_read(wr, data, fsblklen, &off);
   3128 			if (error)
   3129 				return error;
   3130 		}
   3131 		data = (uint8_t *)data + fsblklen;
   3132 		len -= fsblklen;
   3133 		blk++;
   3134 	}
   3135 	return 0;
   3136 }
   3137 
   3138 #ifdef _KERNEL
   3139 
   3140 MODULE(MODULE_CLASS_VFS, wapbl, NULL);
   3141 
   3142 static int
   3143 wapbl_modcmd(modcmd_t cmd, void *arg)
   3144 {
   3145 
   3146 	switch (cmd) {
   3147 	case MODULE_CMD_INIT:
   3148 		wapbl_init();
   3149 		return 0;
   3150 	case MODULE_CMD_FINI:
   3151 		return wapbl_fini();
   3152 	default:
   3153 		return ENOTTY;
   3154 	}
   3155 }
   3156 #endif /* _KERNEL */
   3157