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chfs_write.c revision 1.2
      1 /*	$NetBSD: chfs_write.c,v 1.2 2011/11/24 21:09:37 agc Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2010 Department of Software Engineering,
      5  *		      University of Szeged, Hungary
      6  * Copyright (C) 2010 David Tengeri <dtengeri (at) inf.u-szeged.hu>
      7  * Copyright (C) 2010 Tamas Toth <ttoth (at) inf.u-szeged.hu>
      8  * Copyright (C) 2010 Adam Hoka <ahoka (at) NetBSD.org>
      9  * All rights reserved.
     10  *
     11  * This code is derived from software contributed to The NetBSD Foundation
     12  * by the Department of Software Engineering, University of Szeged, Hungary
     13  *
     14  * Redistribution and use in source and binary forms, with or without
     15  * modification, are permitted provided that the following conditions
     16  * are met:
     17  * 1. Redistributions of source code must retain the above copyright
     18  *    notice, this list of conditions and the following disclaimer.
     19  * 2. Redistributions in binary form must reproduce the above copyright
     20  *    notice, this list of conditions and the following disclaimer in the
     21  *    documentation and/or other materials provided with the distribution.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 /*
     37  * chfs_write.c
     38  *
     39  *  Created on: 2010.02.17.
     40  *      Author: dtengeri
     41  */
     42 
     43 #include <sys/param.h>
     44 #include <sys/buf.h>
     45 
     46 #include "chfs.h"
     47 
     48 int
     49 chfs_write_flash_vnode(struct chfs_mount *chmp,
     50     struct chfs_inode *ip, int prio)
     51 {
     52 	KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
     53 
     54 	struct chfs_flash_vnode *fvnode;
     55 	struct chfs_vnode_cache* chvc;
     56 	struct chfs_node_ref *nref;
     57 	struct iovec vec;
     58 	size_t size, retlen;
     59 	int err = 0, retries = 0;
     60 
     61 	if (ip->ino == CHFS_ROOTINO)
     62 		return 0;
     63 
     64 	fvnode = chfs_alloc_flash_vnode();
     65 	if (!fvnode)
     66 		return ENOMEM;
     67 
     68 	chvc = ip->chvc;
     69 
     70 	/* setting up flash_vnode members */
     71 	size = sizeof(*fvnode);
     72 	//dbg("size: %zu | PADDED: %zu\n", size, CHFS_PAD(size));
     73 	fvnode->magic = htole16(CHFS_FS_MAGIC_BITMASK);
     74 	fvnode->type = htole16(CHFS_NODETYPE_VNODE);
     75 	fvnode->length = htole32(CHFS_PAD(size));
     76 	fvnode->hdr_crc = htole32(crc32(0, (uint8_t *)fvnode,
     77 		CHFS_NODE_HDR_SIZE - 4));
     78 	fvnode->vno = htole64(ip->ino);
     79 	fvnode->version = htole64(++ip->chvc->highest_version);
     80 	fvnode->mode = htole32(ip->mode);
     81 	fvnode->dn_size = htole32(ip->size);
     82 	fvnode->atime = htole32(ip->atime);
     83 	fvnode->ctime = htole32(ip->ctime);
     84 	fvnode->mtime = htole32(ip->mtime);
     85 	fvnode->gid = htole32(ip->gid);
     86 	fvnode->uid = htole32(ip->uid);
     87 	fvnode->node_crc = htole32(crc32(0, (uint8_t *)fvnode, size - 4));
     88 
     89 	/* write out flash_vnode */
     90 retry:
     91 	if (prio == ALLOC_GC) {
     92 		/* the GC calls this function */
     93 		err = chfs_reserve_space_gc(chmp, CHFS_PAD(size));
     94 		if (err)
     95 			goto out;
     96 	} else {
     97 		chfs_gc_trigger(chmp);
     98 		if (prio == ALLOC_NORMAL)
     99 			err = chfs_reserve_space_normal(chmp,
    100 			    CHFS_PAD(size), ALLOC_NORMAL);
    101 		else
    102 			err = chfs_reserve_space_normal(chmp,
    103 			    CHFS_PAD(size), ALLOC_DELETION);
    104 		if (err)
    105 			goto out;
    106 	}
    107 
    108 	nref = chfs_alloc_node_ref(chmp->chm_nextblock);
    109 	if (!nref) {
    110 		err = ENOMEM;
    111 		goto out;
    112 	}
    113 
    114 	mutex_enter(&chmp->chm_lock_sizes);
    115 
    116 	nref->nref_offset = chmp->chm_ebh->eb_size - chmp->chm_nextblock->free_size;
    117 	chfs_change_size_free(chmp, chmp->chm_nextblock, -CHFS_PAD(size));
    118 	vec.iov_base = fvnode;
    119 	vec.iov_len = CHFS_PAD(size);
    120 	err = chfs_write_wbuf(chmp, &vec, 1, nref->nref_offset, &retlen);
    121 	if (err || retlen != CHFS_PAD(size)) {
    122 		chfs_err("error while writing out flash vnode to the media\n");
    123 		chfs_err("err: %d | size: %zu | retlen : %zu\n",
    124 		    err, CHFS_PAD(size), retlen);
    125 		chfs_change_size_dirty(chmp,
    126 		    chmp->chm_nextblock, CHFS_PAD(size));
    127 		if (retries) {
    128 			err = EIO;
    129 			mutex_exit(&chmp->chm_lock_sizes);
    130 			goto out;
    131 		}
    132 
    133 		retries++;
    134 		mutex_exit(&chmp->chm_lock_sizes);
    135 		goto retry;
    136 	}
    137 	//Everything went well
    138 	chfs_change_size_used(chmp,
    139 	    &chmp->chm_blocks[nref->nref_lnr], CHFS_PAD(size));
    140 	mutex_exit(&chmp->chm_lock_sizes);
    141 
    142 	chfs_add_vnode_ref_to_vc(chmp, chvc, nref);
    143 	KASSERT(chmp->chm_blocks[nref->nref_lnr].used_size <= chmp->chm_ebh->eb_size);
    144 out:
    145 	chfs_free_flash_vnode(fvnode);
    146 	return err;
    147 }
    148 
    149 int
    150 chfs_write_flash_dirent(struct chfs_mount *chmp, struct chfs_inode *pdir,
    151     struct chfs_inode *ip, struct chfs_dirent *fd,
    152     ino_t ino, int prio)
    153 {
    154 	KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
    155 
    156 	struct chfs_flash_dirent_node *fdirent;
    157 	struct chfs_node_ref *nref;
    158 	struct iovec vec[2];
    159 	size_t size, retlen;
    160 	int err = 0, retries = 0;
    161 	uint8_t *name;
    162 	size_t namelen;
    163 
    164 	KASSERT(fd->vno != CHFS_ROOTINO);
    165 
    166 	fdirent = chfs_alloc_flash_dirent();
    167 	if (!fdirent)
    168 		return ENOMEM;
    169 
    170 	size = sizeof(*fdirent) + fd->nsize;
    171 	namelen = CHFS_PAD(size) - sizeof(*fdirent);
    172 
    173 	name = kmem_zalloc(namelen, KM_SLEEP);
    174 	memcpy(name, fd->name, fd->nsize);
    175 	//dbg("namelen: %zu | nsize: %hhu\n", namelen, fd->nsize);
    176 
    177 
    178 	//dbg("size: %zu | PADDED: %zu\n", size, CHFS_PAD(size));
    179 	fdirent->magic = htole16(CHFS_FS_MAGIC_BITMASK);
    180 	fdirent->type = htole16(CHFS_NODETYPE_DIRENT);
    181 	fdirent->length = htole32(CHFS_PAD(size));
    182 	fdirent->hdr_crc = htole32(crc32(0, (uint8_t *)fdirent,
    183 		CHFS_NODE_HDR_SIZE - 4));
    184 	fdirent->vno = htole64(ino);
    185 	fdirent->pvno = htole64(pdir->ino);
    186 	fdirent->version = htole64(++pdir->chvc->highest_version);
    187 	fdirent->mctime = ip?ip->ctime:0;
    188 	fdirent->nsize = fd->nsize;
    189 	fdirent->dtype = fd->type;
    190 	fdirent->name_crc = crc32(0, (uint8_t *)&(fd->name), fd->nsize);
    191 	fdirent->node_crc = crc32(0, (uint8_t *)fdirent, sizeof(*fdirent) - 4);
    192 
    193 	vec[0].iov_base = fdirent;
    194 	vec[0].iov_len  = sizeof(*fdirent);
    195 	vec[1].iov_base = name;
    196 	vec[1].iov_len  = namelen;
    197 
    198 retry:
    199 	if (prio == ALLOC_GC) {
    200 		/* the GC calls this function */
    201 		err = chfs_reserve_space_gc(chmp, CHFS_PAD(size));
    202 		if (err)
    203 			goto out;
    204 	} else {
    205 		chfs_gc_trigger(chmp);
    206 		if (prio == ALLOC_NORMAL)
    207 			err = chfs_reserve_space_normal(chmp,
    208 			    CHFS_PAD(size), ALLOC_NORMAL);
    209 		else
    210 			err = chfs_reserve_space_normal(chmp,
    211 			    CHFS_PAD(size), ALLOC_DELETION);
    212 		if (err)
    213 			goto out;
    214 	}
    215 
    216 	nref = chfs_alloc_node_ref(chmp->chm_nextblock);
    217 	if (!nref) {
    218 		err = ENOMEM;
    219 		goto out;
    220 	}
    221 
    222 	mutex_enter(&chmp->chm_lock_sizes);
    223 
    224 	nref->nref_offset = chmp->chm_ebh->eb_size - chmp->chm_nextblock->free_size;
    225 	chfs_change_size_free(chmp, chmp->chm_nextblock, -CHFS_PAD(size));
    226 
    227 	err = chfs_write_wbuf(chmp, vec, 2, nref->nref_offset, &retlen);
    228 	if (err || retlen != CHFS_PAD(size)) {
    229 		chfs_err("error while writing out flash dirent node to the media\n");
    230 		chfs_err("err: %d | size: %zu | retlen : %zu\n",
    231 		    err, CHFS_PAD(size), retlen);
    232 		chfs_change_size_dirty(chmp,
    233 		    chmp->chm_nextblock, CHFS_PAD(size));
    234 		if (retries) {
    235 			err = EIO;
    236 			mutex_exit(&chmp->chm_lock_sizes);
    237 			goto out;
    238 		}
    239 
    240 		retries++;
    241 		mutex_exit(&chmp->chm_lock_sizes);
    242 		goto retry;
    243 	}
    244 
    245 
    246 	// Everything went well
    247 	chfs_change_size_used(chmp,
    248 	    &chmp->chm_blocks[nref->nref_lnr], CHFS_PAD(size));
    249 	mutex_exit(&chmp->chm_lock_sizes);
    250 	KASSERT(chmp->chm_blocks[nref->nref_lnr].used_size <= chmp->chm_ebh->eb_size);
    251 	fd->nref = nref;
    252 	if (prio != ALLOC_DELETION) {
    253 		chfs_add_node_to_list(chmp,
    254 			pdir->chvc, nref, &pdir->chvc->dirents);
    255 	}
    256 out:
    257 	chfs_free_flash_dirent(fdirent);
    258 	return err;
    259 }
    260 
    261 /**
    262  * chfs_write_flash_dnode - write out a data node to flash
    263  * @chmp: chfs mount structure
    264  * @vp: vnode where the data belongs to
    265  * @bp: buffer contains data
    266  */
    267 int
    268 chfs_write_flash_dnode(struct chfs_mount *chmp, struct vnode *vp,
    269     struct buf *bp, struct chfs_full_dnode *fd)
    270 {
    271 	KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
    272 
    273 	int err = 0, retries = 0;
    274 	size_t size, retlen;
    275 	off_t ofs;
    276 	struct chfs_flash_data_node *dnode;
    277 	struct chfs_node_ref *nref;
    278 	struct chfs_inode *ip = VTOI(vp);
    279 	struct iovec vec[2];
    280 	uint32_t len;
    281 	void *tmpbuf = NULL;
    282 
    283 	KASSERT(ip->ino != CHFS_ROOTINO);
    284 
    285 	dnode = chfs_alloc_flash_dnode();
    286 	if (!dnode)
    287 		return ENOMEM;
    288 
    289 	/* initialize flash data node */
    290 	ofs = bp->b_blkno * PAGE_SIZE;
    291 	//dbg("vp->v_size: %ju, bp->b_blkno: %ju, bp-b_data: %p,"
    292 	//    " bp->b_resid: %ju\n",
    293 	//    (uintmax_t )vp->v_size, (uintmax_t )bp->b_blkno,
    294 	//    bp->b_data, (uintmax_t )bp->b_resid);
    295 	//dbg("[XXX]vp->v_size - ofs: %llu\n", (vp->v_size - ofs));
    296 	len = MIN((vp->v_size - ofs), bp->b_resid);
    297 	size = sizeof(*dnode) + len;
    298 
    299 	dnode->magic = htole16(CHFS_FS_MAGIC_BITMASK);
    300 	dnode->type = htole16(CHFS_NODETYPE_DATA);
    301 	dnode->length = htole32(CHFS_PAD(size));
    302 	dnode->hdr_crc = htole32(crc32(0, (uint8_t *)dnode,
    303 		CHFS_NODE_HDR_SIZE - 4));
    304 	dnode->vno = htole64(ip->ino);
    305 	dnode->version = htole64(++ip->chvc->highest_version);
    306 	dnode->offset = htole64(ofs);
    307 	dnode->data_length = htole32(len);
    308 	dnode->data_crc = htole32(crc32(0, (uint8_t *)bp->b_data, len));
    309 	dnode->node_crc = htole32(crc32(0, (uint8_t *)dnode,
    310 		sizeof(*dnode) - 4));
    311 
    312 	dbg("dnode @%llu %ub v%llu\n", (unsigned long long)dnode->offset,
    313 		dnode->data_length, (unsigned long long)dnode->version);
    314 
    315 	if (CHFS_PAD(size) - sizeof(*dnode)) {
    316 		tmpbuf = kmem_zalloc(CHFS_PAD(size)
    317 		    - sizeof(*dnode), KM_SLEEP);
    318 		memcpy(tmpbuf, bp->b_data, len);
    319 	}
    320 
    321 	/* creating iovecs for wbuf */
    322 	vec[0].iov_base = dnode;
    323 	vec[0].iov_len = sizeof(*dnode);
    324 	vec[1].iov_base = tmpbuf;
    325 	vec[1].iov_len = CHFS_PAD(size) - sizeof(*dnode);
    326 
    327 	fd->frags = 0;
    328 	fd->ofs = ofs;
    329 	fd->size = len;
    330 
    331 retry:
    332 
    333 	/* Reserve space for data node. This will set up the next eraseblock
    334 	 * where to we will write.
    335 	 */
    336 
    337 	chfs_gc_trigger(chmp);
    338 	err = chfs_reserve_space_normal(chmp,
    339 	    CHFS_PAD(size), ALLOC_NORMAL);
    340 	if (err)
    341 		goto out;
    342 
    343 	nref = chfs_alloc_node_ref(chmp->chm_nextblock);
    344 	if (!nref) {
    345 		err = ENOMEM;
    346 		goto out;
    347 	}
    348 
    349 	nref->nref_offset =
    350 	    chmp->chm_ebh->eb_size - chmp->chm_nextblock->free_size;
    351 
    352 	KASSERT(nref->nref_offset < chmp->chm_ebh->eb_size);
    353 
    354 	mutex_enter(&chmp->chm_lock_sizes);
    355 
    356 	chfs_change_size_free(chmp,
    357 	    chmp->chm_nextblock, -CHFS_PAD(size));
    358 
    359 	//dbg("vno: %llu nref lnr: %u offset: %u\n",
    360 	//    dnode->vno, nref->nref_lnr, nref->nref_offset);
    361 
    362 	err = chfs_write_wbuf(chmp, vec, 2, nref->nref_offset, &retlen);
    363 	if (err || retlen != CHFS_PAD(size)) {
    364 		chfs_err("error while writing out flash data node to the media\n");
    365 		chfs_err("err: %d | size: %zu | retlen : %zu\n",
    366 		    err, size, retlen);
    367 		chfs_change_size_dirty(chmp,
    368 		    chmp->chm_nextblock, CHFS_PAD(size));
    369 		if (retries) {
    370 			err = EIO;
    371 			mutex_exit(&chmp->chm_lock_sizes);
    372 			goto out;
    373 		}
    374 
    375 		retries++;
    376 		mutex_exit(&chmp->chm_lock_sizes);
    377 		goto retry;
    378 	}
    379 	/* Everything went well */
    380 	ip->write_size += fd->size;
    381 	chfs_change_size_used(chmp,
    382 	    &chmp->chm_blocks[nref->nref_lnr], CHFS_PAD(size));
    383 	mutex_exit(&chmp->chm_lock_sizes);
    384 
    385 	KASSERT(chmp->chm_blocks[nref->nref_lnr].used_size <= chmp->chm_ebh->eb_size);
    386 	fd->nref = nref;
    387 	chfs_add_node_to_list(chmp, ip->chvc, nref, &ip->chvc->dnode);
    388 out:
    389 	chfs_free_flash_dnode(dnode);
    390 	if (CHFS_PAD(size) - sizeof(*dnode)) {
    391 		kmem_free(tmpbuf, CHFS_PAD(size) - sizeof(*dnode));
    392 	}
    393 
    394 	return err;
    395 }
    396 
    397 /**
    398  * chfs_do_link - makes a copy from a node
    399  * @old: old node
    400  * @oldfd: dirent of old node
    401  * @parent: parent of new node
    402  * @name: name of new node
    403  * @namelen: length of name
    404  * This function writes the dirent of the new node to the media.
    405  */
    406 int
    407 chfs_do_link(struct chfs_inode *ip, struct chfs_inode *parent, const char *name, int namelen, enum vtype type)
    408 {
    409 	int error = 0;
    410 	struct vnode *vp = ITOV(ip);
    411 	struct ufsmount *ump = VFSTOUFS(vp->v_mount);
    412 	struct chfs_mount *chmp = ump->um_chfs;
    413 	struct chfs_dirent *newfd = NULL;
    414 //	struct chfs_dirent *fd = NULL;
    415 
    416 	//dbg("link vno: %llu\n", ip->ino);
    417 
    418 	newfd = chfs_alloc_dirent(namelen + 1);
    419 
    420 	newfd->vno = ip->ino;
    421 	newfd->type = type;
    422 	newfd->nsize = namelen;
    423 	memcpy(newfd->name, name, namelen);
    424 	newfd->name[newfd->nsize] = 0;
    425 //	newfd->next = NULL;
    426 
    427 	ip->chvc->nlink++;
    428 	parent->chvc->nlink++;
    429 	ip->iflag |= IN_CHANGE;
    430 	chfs_update(vp, NULL, NULL, UPDATE_WAIT);
    431 
    432 	mutex_enter(&chmp->chm_lock_mountfields);
    433 
    434 	error = chfs_write_flash_vnode(chmp, ip, ALLOC_NORMAL);
    435 	if (error)
    436 		return error;
    437 
    438 	error = chfs_write_flash_dirent(chmp,
    439 	    parent, ip, newfd, ip->ino, ALLOC_NORMAL);
    440 	/* TODO: what should we do if error isn't zero? */
    441 
    442 	mutex_exit(&chmp->chm_lock_mountfields);
    443 
    444 	/* add fd to the fd list */
    445 	TAILQ_INSERT_TAIL(&parent->dents, newfd, fds);
    446 #if 0
    447 	fd = parent->dents;
    448 	if (!fd) {
    449 		parent->dents = newfd;
    450 	} else {
    451 		while (fd->next)
    452 			fd = fd->next;
    453 		fd->next = newfd;
    454 	}
    455 #endif
    456 
    457 	return error;
    458 }
    459 
    460 
    461 /**
    462  * chfs_do_unlink - delete a node
    463  * @ip: node what we'd like to delete
    464  * @parent: parent of the node
    465  * @name: name of the node
    466  * @namelen: length of name
    467  * This function set the nlink and vno of the node zero and write its dirent to the media.
    468  */
    469 int
    470 chfs_do_unlink(struct chfs_inode *ip,
    471     struct chfs_inode *parent, const char *name, int namelen)
    472 {
    473 	struct chfs_dirent *fd, *tmpfd;
    474 	int error = 0;
    475 	struct vnode *vp = ITOV(ip);
    476 	struct ufsmount *ump = VFSTOUFS(vp->v_mount);
    477 	struct chfs_mount *chmp = ump->um_chfs;
    478 	struct chfs_node_ref *nref;
    479 
    480 	//dbg("unlink vno: %llu\n", ip->ino);
    481 
    482 	vflushbuf(vp, 0);
    483 
    484 	mutex_enter(&chmp->chm_lock_mountfields);
    485 
    486 	/* remove the full direntry from the parent dents list */
    487 	TAILQ_FOREACH_SAFE(fd, &parent->dents, fds, tmpfd) {
    488 		if (fd->vno == ip->ino &&
    489 		    fd->nsize == namelen &&
    490 		    !memcmp(fd->name, name, fd->nsize)) {
    491 			if (fd->type == VDIR && ip->chvc->nlink == 2)
    492 				ip->chvc->nlink = 0;
    493 			else
    494 				ip->chvc->nlink--;
    495 
    496 			fd->type = VNON;
    497 
    498 			TAILQ_REMOVE(&parent->dents, fd, fds);
    499 
    500 			/* remove nref from dirents list */
    501 			nref = parent->chvc->dirents;
    502 			if (nref == fd->nref) {
    503 				nref->nref_next = fd->nref->nref_next;
    504 			} else {
    505 				while (nref->nref_next && nref->nref_next != fd->nref)
    506 					nref = nref->nref_next;
    507 				if (nref->nref_next)
    508 					nref->nref_next = fd->nref->nref_next;
    509 			}
    510 
    511 			//dbg("FD->NREF vno: %llu, lnr: %u, ofs: %u\n",
    512 			//    fd->vno, fd->nref->nref_lnr, fd->nref->nref_offset);
    513 			chfs_mark_node_obsolete(chmp, fd->nref);
    514 
    515 			error = chfs_write_flash_dirent(chmp,
    516 			    parent, ip, fd, 0, ALLOC_DELETION);
    517 
    518 			//dbg("FD->NREF vno: %llu, lnr: %u, ofs: %u\n",
    519 			//    fd->vno, fd->nref->nref_lnr, fd->nref->nref_offset);
    520 			chfs_mark_node_obsolete(chmp, fd->nref);
    521 
    522 			nref = ip->chvc->dnode;
    523 			while (nref != (struct chfs_node_ref *)ip->chvc) {
    524 				//dbg("DATA NREF\n");
    525 				chfs_mark_node_obsolete(chmp, nref);
    526 				nref = nref->nref_next;
    527 			}
    528 			ip->chvc->dnode = (struct chfs_node_ref *)ip->chvc;
    529 
    530 			nref = ip->chvc->v;
    531 			while (nref != (struct chfs_node_ref *)ip->chvc) {
    532 				//dbg("V NREF\n");
    533 				chfs_mark_node_obsolete(chmp, nref);
    534 				nref = nref->nref_next;
    535 			}
    536 			ip->chvc->v = ip->chvc->v->nref_next;
    537 
    538 			parent->chvc->nlink--;
    539 			//TODO: if error
    540 		}
    541 	}
    542 	mutex_exit(&chmp->chm_lock_mountfields);
    543 
    544 	return error;
    545 }
    546