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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 /*
     22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     27 
     28 #include <sys/types.h>
     29 #include <sys/t_lock.h>
     30 #include <sys/param.h>
     31 #include <sys/time.h>
     32 #include <sys/systm.h>
     33 #include <sys/sysmacros.h>
     34 #include <sys/resource.h>
     35 #include <sys/signal.h>
     36 #include <sys/cred.h>
     37 #include <sys/user.h>
     38 #include <sys/buf.h>
     39 #include <sys/vfs.h>
     40 #include <sys/vnode.h>
     41 #include <sys/proc.h>
     42 #include <sys/disp.h>
     43 #include <sys/file.h>
     44 #include <sys/fcntl.h>
     45 #include <sys/flock.h>
     46 #include <sys/atomic.h>
     47 #include <sys/kmem.h>
     48 #include <sys/uio.h>
     49 #include <sys/conf.h>
     50 #include <sys/mman.h>
     51 #include <sys/pathname.h>
     52 #include <sys/debug.h>
     53 #include <sys/vmmeter.h>
     54 #include <sys/vmsystm.h>
     55 #include <sys/cmn_err.h>
     56 #include <sys/filio.h>
     57 #include <sys/dnlc.h>
     58 
     59 #include <sys/fs/ufs_filio.h>
     60 #include <sys/fs/ufs_lockfs.h>
     61 #include <sys/fs/ufs_fs.h>
     62 #include <sys/fs/ufs_inode.h>
     63 #include <sys/fs/ufs_fsdir.h>
     64 #include <sys/fs/ufs_quota.h>
     65 #include <sys/fs/ufs_trans.h>
     66 #include <sys/fs/ufs_log.h>
     67 #include <sys/dirent.h>		/* must be AFTER <sys/fs/fsdir.h>! */
     68 #include <sys/errno.h>
     69 #include <sys/sysinfo.h>
     70 
     71 #include <vm/hat.h>
     72 #include <vm/page.h>
     73 #include <vm/pvn.h>
     74 #include <vm/as.h>
     75 #include <vm/seg.h>
     76 #include <vm/seg_map.h>
     77 #include <vm/seg_vn.h>
     78 #include <vm/rm.h>
     79 #include <sys/swap.h>
     80 #include <sys/model.h>
     81 #include <sys/policy.h>
     82 
     83 #include "fs/fs_subr.h"
     84 
     85 /*
     86  * ufs_fioio is the ufs equivalent of NFS_CNVT and is tailored to
     87  * metamucil's needs.  It may change at any time.
     88  */
     89 /* ARGSUSED */
     90 int
     91 ufs_fioio(
     92 	struct vnode	*vp,		/* any file on the fs */
     93 	struct fioio	*fiou,		/* fioio struct in userland */
     94 	int		flag,		/* flag from VOP_IOCTL() */
     95 	struct cred	*cr)		/* credentials from ufs_ioctl */
     96 {
     97 	int		error	= 0;
     98 	struct vnode	*vpio	= NULL;	/* vnode for inode open */
     99 	struct inode	*ipio	= NULL;	/* inode for inode open */
    100 	struct file	*fpio	= NULL;	/* file  for inode open */
    101 	struct inode	*ip;		/* inode for file system */
    102 	struct fs	*fs;		/* fs    for file system */
    103 	STRUCT_DECL(fioio, fio);	/* copy of user's fioio struct */
    104 
    105 	/*
    106 	 * must be privileged
    107 	 */
    108 	if (secpolicy_fs_config(cr, vp->v_vfsp) != 0)
    109 		return (EPERM);
    110 
    111 	STRUCT_INIT(fio, flag & DATAMODEL_MASK);
    112 
    113 	/*
    114 	 * get user's copy of fioio struct
    115 	 */
    116 	if (copyin(fiou, STRUCT_BUF(fio), STRUCT_SIZE(fio)))
    117 		return (EFAULT);
    118 
    119 	ip = VTOI(vp);
    120 	fs = ip->i_fs;
    121 
    122 	/*
    123 	 * check the inode number against the fs's inode number bounds
    124 	 */
    125 	if (STRUCT_FGET(fio, fio_ino) < UFSROOTINO)
    126 		return (ESRCH);
    127 	if (STRUCT_FGET(fio, fio_ino) >= fs->fs_ncg * fs->fs_ipg)
    128 		return (ESRCH);
    129 
    130 	rw_enter(&ip->i_ufsvfs->vfs_dqrwlock, RW_READER);
    131 
    132 	/*
    133 	 * get the inode
    134 	 */
    135 	error = ufs_iget(ip->i_vfs, STRUCT_FGET(fio, fio_ino), &ipio, cr);
    136 
    137 	rw_exit(&ip->i_ufsvfs->vfs_dqrwlock);
    138 
    139 	if (error)
    140 		return (error);
    141 
    142 	/*
    143 	 * check the generation number
    144 	 */
    145 	rw_enter(&ipio->i_contents, RW_READER);
    146 	if (ipio->i_gen != STRUCT_FGET(fio, fio_gen)) {
    147 		error = ESTALE;
    148 		rw_exit(&ipio->i_contents);
    149 		goto errout;
    150 	}
    151 
    152 	/*
    153 	 * check if the inode is free
    154 	 */
    155 	if (ipio->i_mode == 0) {
    156 		error = ENOENT;
    157 		rw_exit(&ipio->i_contents);
    158 		goto errout;
    159 	}
    160 	rw_exit(&ipio->i_contents);
    161 
    162 	/*
    163 	 *	Adapted from copen: get a file struct
    164 	 *	Large Files: We open this file descriptor with FOFFMAX flag
    165 	 *	set so that it will be like a large file open.
    166 	 */
    167 	if (falloc(NULL, (FREAD|FOFFMAX), &fpio, STRUCT_FADDR(fio, fio_fd)))
    168 		goto errout;
    169 
    170 	/*
    171 	 *	Adapted from vn_open: check access and then open the file
    172 	 */
    173 	vpio = ITOV(ipio);
    174 	if (error = VOP_ACCESS(vpio, VREAD, 0, cr, NULL))
    175 		goto errout;
    176 
    177 	if (error = VOP_OPEN(&vpio, FREAD, cr, NULL))
    178 		goto errout;
    179 
    180 	/*
    181 	 *	Adapted from copen: initialize the file struct
    182 	 */
    183 	fpio->f_vnode = vpio;
    184 
    185 	/*
    186 	 * return the fd
    187 	 */
    188 	if (copyout(STRUCT_BUF(fio), fiou, STRUCT_SIZE(fio))) {
    189 		error = EFAULT;
    190 		goto errout;
    191 	}
    192 	setf(STRUCT_FGET(fio, fio_fd), fpio);
    193 	mutex_exit(&fpio->f_tlock);
    194 	return (0);
    195 errout:
    196 	/*
    197 	 * free the file struct and fd
    198 	 */
    199 	if (fpio) {
    200 		setf(STRUCT_FGET(fio, fio_fd), NULL);
    201 		unfalloc(fpio);
    202 	}
    203 
    204 	/*
    205 	 * release the hold on the inode
    206 	 */
    207 	if (ipio)
    208 		VN_RELE(ITOV(ipio));
    209 	return (error);
    210 }
    211 
    212 /*
    213  * ufs_fiosatime
    214  *	set access time w/o altering change time.  This ioctl is tailored
    215  *	to metamucil's needs and may change at any time.
    216  */
    217 int
    218 ufs_fiosatime(
    219 	struct vnode	*vp,		/* file's vnode */
    220 	struct timeval	*tvu,		/* struct timeval in userland */
    221 	int		flag,		/* flag from VOP_IOCTL() */
    222 	struct cred	*cr)		/* credentials from ufs_ioctl */
    223 {
    224 	struct inode	*ip;		/* inode for vp */
    225 	struct timeval32 tv;		/* copy of user's timeval */
    226 	int now = 0;
    227 
    228 	/*
    229 	 * must have sufficient privileges
    230 	 */
    231 	if (secpolicy_fs_config(cr, vp->v_vfsp) != 0)
    232 		return (EPERM);
    233 
    234 	/*
    235 	 * get user's copy of timeval struct and check values
    236 	 * if input is NULL, will set time to now
    237 	 */
    238 	if (tvu == NULL) {
    239 		now = 1;
    240 	} else {
    241 		if ((flag & DATAMODEL_MASK) == DATAMODEL_ILP32) {
    242 			if (copyin(tvu, &tv, sizeof (tv)))
    243 				return (EFAULT);
    244 		} else {
    245 			struct timeval tv64;
    246 
    247 			if (copyin(tvu, &tv64, sizeof (tv64)))
    248 				return (EFAULT);
    249 			if (TIMEVAL_OVERFLOW(&tv64))
    250 				return (EOVERFLOW);
    251 			TIMEVAL_TO_TIMEVAL32(&tv, &tv64);
    252 		}
    253 
    254 		if (tv.tv_usec < 0 || tv.tv_usec >= 1000000)
    255 			return (EINVAL);
    256 	}
    257 
    258 	/*
    259 	 * update access time
    260 	 */
    261 	ip = VTOI(vp);
    262 	rw_enter(&ip->i_contents, RW_WRITER);
    263 	ITIMES_NOLOCK(ip);
    264 	if (now) {
    265 		mutex_enter(&ufs_iuniqtime_lock);
    266 		ip->i_atime = iuniqtime;
    267 		mutex_exit(&ufs_iuniqtime_lock);
    268 	} else {
    269 		ip->i_atime = tv;
    270 	}
    271 	ip->i_flag |= IMODACC;
    272 	rw_exit(&ip->i_contents);
    273 
    274 	return (0);
    275 }
    276 
    277 /*
    278  * ufs_fiogdio
    279  *	Get delayed-io state.  This ioctl is tailored
    280  *	to metamucil's needs and may change at any time.
    281  */
    282 /* ARGSUSED */
    283 int
    284 ufs_fiogdio(
    285 	struct vnode	*vp,		/* file's vnode */
    286 	uint_t		*diop,		/* dio state returned here */
    287 	int		flag,		/* flag from ufs_ioctl */
    288 	struct cred	*cr)		/* credentials from ufs_ioctl */
    289 {
    290 	struct ufsvfs	*ufsvfsp	= VTOI(vp)->i_ufsvfs;
    291 
    292 	/*
    293 	 * forcibly unmounted
    294 	 */
    295 	if (ufsvfsp == NULL)
    296 		return (EIO);
    297 
    298 	if (suword32(diop, ufsvfsp->vfs_dio))
    299 		return (EFAULT);
    300 	return (0);
    301 }
    302 
    303 /*
    304  * ufs_fiosdio
    305  *	Set delayed-io state.  This ioctl is tailored
    306  *	to metamucil's needs and may change at any time.
    307  */
    308 int
    309 ufs_fiosdio(
    310 	struct vnode	*vp,		/* file's vnode */
    311 	uint_t		*diop,		/* dio flag */
    312 	int		flag,		/* flag from ufs_ioctl */
    313 	struct cred	*cr)		/* credentials from ufs_ioctl */
    314 {
    315 	uint_t		dio;		/* copy of user's dio */
    316 	struct inode	*ip;		/* inode for vp */
    317 	struct ufsvfs	*ufsvfsp;
    318 	struct fs	*fs;
    319 	struct ulockfs	*ulp;
    320 	int		error = 0;
    321 
    322 #ifdef lint
    323 	flag = flag;
    324 #endif
    325 
    326 	/* check input conditions */
    327 	if (secpolicy_fs_config(cr, vp->v_vfsp) != 0)
    328 		return (EPERM);
    329 
    330 	if (copyin(diop, &dio, sizeof (dio)))
    331 		return (EFAULT);
    332 
    333 	if (dio > 1)
    334 		return (EINVAL);
    335 
    336 	/* file system has been forcibly unmounted */
    337 	if (VTOI(vp)->i_ufsvfs == NULL)
    338 		return (EIO);
    339 
    340 	ip = VTOI(vp);
    341 	ufsvfsp = ip->i_ufsvfs;
    342 	ulp = &ufsvfsp->vfs_ulockfs;
    343 
    344 	/* logging file system; dio ignored */
    345 	if (TRANS_ISTRANS(ufsvfsp))
    346 		return (error);
    347 
    348 	/* hold the mutex to prevent race with a lockfs request */
    349 	vfs_lock_wait(vp->v_vfsp);
    350 	mutex_enter(&ulp->ul_lock);
    351 	atomic_add_long(&ufs_quiesce_pend, 1);
    352 
    353 	if (ULOCKFS_IS_HLOCK(ulp)) {
    354 		error = EIO;
    355 		goto out;
    356 	}
    357 
    358 	if (ULOCKFS_IS_ELOCK(ulp)) {
    359 		error = EBUSY;
    360 		goto out;
    361 	}
    362 	/* wait for outstanding accesses to finish */
    363 	if (error = ufs_quiesce(ulp))
    364 		goto out;
    365 
    366 	/* flush w/invalidate */
    367 	if (error = ufs_flush(vp->v_vfsp))
    368 		goto out;
    369 
    370 	/*
    371 	 * update dio
    372 	 */
    373 	mutex_enter(&ufsvfsp->vfs_lock);
    374 	ufsvfsp->vfs_dio = dio;
    375 
    376 	/*
    377 	 * enable/disable clean flag processing
    378 	 */
    379 	fs = ip->i_fs;
    380 	if (fs->fs_ronly == 0 &&
    381 	    fs->fs_clean != FSBAD &&
    382 	    fs->fs_clean != FSLOG) {
    383 		if (dio)
    384 			fs->fs_clean = FSSUSPEND;
    385 		else
    386 			fs->fs_clean = FSACTIVE;
    387 		ufs_sbwrite(ufsvfsp);
    388 		mutex_exit(&ufsvfsp->vfs_lock);
    389 	} else
    390 		mutex_exit(&ufsvfsp->vfs_lock);
    391 out:
    392 	/*
    393 	 * we need this broadcast because of the ufs_quiesce call above
    394 	 */
    395 	atomic_add_long(&ufs_quiesce_pend, -1);
    396 	cv_broadcast(&ulp->ul_cv);
    397 	mutex_exit(&ulp->ul_lock);
    398 	vfs_unlock(vp->v_vfsp);
    399 	return (error);
    400 }
    401 
    402 /*
    403  * ufs_fioffs - ioctl handler for flushing file system
    404  */
    405 /* ARGSUSED */
    406 int
    407 ufs_fioffs(
    408 	struct vnode	*vp,
    409 	char 		*vap,		/* must be NULL - reserved */
    410 	struct cred	*cr)		/* credentials from ufs_ioctl */
    411 {
    412 	int error;
    413 	struct ufsvfs	*ufsvfsp;
    414 	struct ulockfs	*ulp;
    415 
    416 	/* file system has been forcibly unmounted */
    417 	ufsvfsp = VTOI(vp)->i_ufsvfs;
    418 	if (ufsvfsp == NULL)
    419 		return (EIO);
    420 
    421 	ulp = &ufsvfsp->vfs_ulockfs;
    422 
    423 	/*
    424 	 * suspend the delete thread
    425 	 *	this must be done outside the lockfs locking protocol
    426 	 */
    427 	vfs_lock_wait(vp->v_vfsp);
    428 	ufs_thread_suspend(&ufsvfsp->vfs_delete);
    429 
    430 	/* hold the mutex to prevent race with a lockfs request */
    431 	mutex_enter(&ulp->ul_lock);
    432 	atomic_add_long(&ufs_quiesce_pend, 1);
    433 
    434 	if (ULOCKFS_IS_HLOCK(ulp)) {
    435 		error = EIO;
    436 		goto out;
    437 	}
    438 	if (ULOCKFS_IS_ELOCK(ulp)) {
    439 		error = EBUSY;
    440 		goto out;
    441 	}
    442 	/* wait for outstanding accesses to finish */
    443 	if (error = ufs_quiesce(ulp))
    444 		goto out;
    445 
    446 	/*
    447 	 * If logging, and the logmap was marked as not rollable,
    448 	 * make it rollable now, and start the trans_roll thread and
    449 	 * the reclaim thread.  The log at this point is safe to write to.
    450 	 */
    451 	if (ufsvfsp->vfs_log) {
    452 		ml_unit_t	*ul = ufsvfsp->vfs_log;
    453 		struct fs	*fsp = ufsvfsp->vfs_fs;
    454 		int		err;
    455 
    456 		if (ul->un_flags & LDL_NOROLL) {
    457 			ul->un_flags &= ~LDL_NOROLL;
    458 			logmap_start_roll(ul);
    459 			if (!fsp->fs_ronly && (fsp->fs_reclaim &
    460 			    (FS_RECLAIM|FS_RECLAIMING))) {
    461 				fsp->fs_reclaim &= ~FS_RECLAIM;
    462 				fsp->fs_reclaim |= FS_RECLAIMING;
    463 				ufs_thread_start(&ufsvfsp->vfs_reclaim,
    464 				    ufs_thread_reclaim, vp->v_vfsp);
    465 				if (!fsp->fs_ronly) {
    466 					TRANS_SBWRITE(ufsvfsp,
    467 					    TOP_SBUPDATE_UPDATE);
    468 					if (err =
    469 					    geterror(ufsvfsp->vfs_bufp)) {
    470 						refstr_t	*mntpt;
    471 						mntpt = vfs_getmntpoint(
    472 						    vp->v_vfsp);
    473 						cmn_err(CE_NOTE,
    474 						    "Filesystem Flush "
    475 						    "Failed to update "
    476 						    "Reclaim Status for "
    477 						    " %s, Write failed to "
    478 						    "update superblock, "
    479 						    "error %d",
    480 						    refstr_value(mntpt),
    481 						    err);
    482 						refstr_rele(mntpt);
    483 					}
    484 				}
    485 			}
    486 		}
    487 	}
    488 
    489 	/* synchronously flush dirty data and metadata */
    490 	error = ufs_flush(vp->v_vfsp);
    491 
    492 out:
    493 	atomic_add_long(&ufs_quiesce_pend, -1);
    494 	cv_broadcast(&ulp->ul_cv);
    495 	mutex_exit(&ulp->ul_lock);
    496 	vfs_unlock(vp->v_vfsp);
    497 
    498 	/*
    499 	 * allow the delete thread to continue
    500 	 */
    501 	ufs_thread_continue(&ufsvfsp->vfs_delete);
    502 	return (error);
    503 }
    504 
    505 /*
    506  * ufs_fioisbusy
    507  *	Get number of references on this vnode.
    508  *	Contract-private interface for Legato's NetWorker product.
    509  */
    510 /* ARGSUSED */
    511 int
    512 ufs_fioisbusy(struct vnode *vp, int *isbusy, struct cred *cr)
    513 {
    514 	int is_it_busy;
    515 
    516 	/*
    517 	 * The caller holds one reference, there may be one in the dnlc
    518 	 * so we need to flush it.
    519 	 */
    520 	if (vp->v_count > 1)
    521 		dnlc_purge_vp(vp);
    522 	/*
    523 	 * Since we've just flushed the dnlc and we hold a reference
    524 	 * to this vnode, then anything but 1 means busy (this had
    525 	 * BETTER not be zero!). Also, it's possible for someone to
    526 	 * have this file mmap'ed with no additional reference count.
    527 	 */
    528 	ASSERT(vp->v_count > 0);
    529 	if ((vp->v_count == 1) && (VTOI(vp)->i_mapcnt == 0))
    530 		is_it_busy = 0;
    531 	else
    532 		is_it_busy = 1;
    533 
    534 	if (suword32(isbusy, is_it_busy))
    535 		return (EFAULT);
    536 	return (0);
    537 }
    538 
    539 /* ARGSUSED */
    540 int
    541 ufs_fiodirectio(struct vnode *vp, int cmd, struct cred *cr)
    542 {
    543 	int		error	= 0;
    544 	struct inode	*ip	= VTOI(vp);
    545 
    546 	/*
    547 	 * Acquire reader lock and set/reset direct mode
    548 	 */
    549 	rw_enter(&ip->i_contents, RW_READER);
    550 	mutex_enter(&ip->i_tlock);
    551 	if (cmd == DIRECTIO_ON)
    552 		ip->i_flag |= IDIRECTIO;	/* enable direct mode */
    553 	else if (cmd == DIRECTIO_OFF)
    554 		ip->i_flag &= ~IDIRECTIO;	/* disable direct mode */
    555 	else
    556 		error = EINVAL;
    557 	mutex_exit(&ip->i_tlock);
    558 	rw_exit(&ip->i_contents);
    559 	return (error);
    560 }
    561 
    562 /*
    563  * ufs_fiotune
    564  *	Allow some tunables to be set on a mounted fs
    565  */
    566 int
    567 ufs_fiotune(struct vnode *vp, struct fiotune *uftp, struct cred *cr)
    568 {
    569 	struct fiotune	ftp;
    570 	struct fs	*fs;
    571 	struct ufsvfs	*ufsvfsp;
    572 
    573 	/*
    574 	 * must have sufficient privileges
    575 	 */
    576 	if (secpolicy_fs_config(cr, vp->v_vfsp) != 0)
    577 		return (EPERM);
    578 
    579 	/*
    580 	 * get user's copy
    581 	 */
    582 	if (copyin(uftp, &ftp, sizeof (ftp)))
    583 		return (EFAULT);
    584 
    585 	/*
    586 	 * some minimal sanity checks
    587 	 */
    588 	if ((ftp.maxcontig <= 0) ||
    589 	    (ftp.rotdelay != 0) ||
    590 	    (ftp.maxbpg <= 0) ||
    591 	    (ftp.minfree < 0) ||
    592 	    (ftp.minfree > 99) ||
    593 	    ((ftp.optim != FS_OPTTIME) && (ftp.optim != FS_OPTSPACE)))
    594 		return (EINVAL);
    595 
    596 	/*
    597 	 * update superblock but don't write it!  If it gets out, fine.
    598 	 */
    599 	fs = VTOI(vp)->i_fs;
    600 
    601 	fs->fs_maxcontig = ftp.maxcontig;
    602 	fs->fs_rotdelay = ftp.rotdelay;
    603 	fs->fs_maxbpg = ftp.maxbpg;
    604 	fs->fs_minfree = ftp.minfree;
    605 	fs->fs_optim = ftp.optim;
    606 
    607 	/*
    608 	 * Adjust cluster based on the new maxcontig. The cluster size
    609 	 * can be any positive value. The check for this is done above.
    610 	 */
    611 	ufsvfsp = VTOI(vp)->i_ufsvfs;
    612 	ufsvfsp->vfs_ioclustsz = fs->fs_bsize * fs->fs_maxcontig;
    613 
    614 	/*
    615 	 * Adjust minfrags from minfree
    616 	 */
    617 	ufsvfsp->vfs_minfrags = (int)((int64_t)fs->fs_dsize *
    618 	    fs->fs_minfree / 100);
    619 
    620 	/*
    621 	 * Write the superblock
    622 	 */
    623 	if (fs->fs_ronly == 0) {
    624 		TRANS_BEGIN_ASYNC(ufsvfsp, TOP_SBUPDATE_UPDATE,
    625 		    TOP_SBWRITE_SIZE);
    626 		TRANS_SBWRITE(ufsvfsp, TOP_SBUPDATE_UPDATE);
    627 		TRANS_END_ASYNC(ufsvfsp, TOP_SBUPDATE_UPDATE, TOP_SBWRITE_SIZE);
    628 	}
    629 
    630 	return (0);
    631 }
    632 
    633 /*
    634  * Lseek support for finding holes (cmd == _FIO_SEEK_HOLE) and
    635  * data (cmd == _FIO_SEEK_DATA). "off" is an in/out parameter.
    636  */
    637 int
    638 ufs_fio_holey(vnode_t *vp, int cmd, offset_t *off)
    639 {
    640 	inode_t	*ip = VTOI(vp);
    641 	u_offset_t noff = (u_offset_t)*off; /* new offset */
    642 	u_offset_t isz;
    643 	int error;
    644 	boolean_t hole;
    645 
    646 	rw_enter(&ip->i_contents, RW_READER);
    647 	isz = ip->i_size;
    648 	if (noff >= isz)  {
    649 		rw_exit(&ip->i_contents);
    650 		return (ENXIO);
    651 	}
    652 
    653 	/*
    654 	 * Check for the usual case where a file has no holes.
    655 	 * If so we can optimise to set the end of the file as the first
    656 	 * (virtual) hole. This avoids bmap_find() searching through
    657 	 * every block in the file for a (non-existent) hole.
    658 	 */
    659 	if (!bmap_has_holes(ip)) {
    660 		rw_exit(&ip->i_contents);
    661 		if (cmd == _FIO_SEEK_HOLE) {
    662 			*off = isz;
    663 			return (0);
    664 		}
    665 		/* *off must already point to valid data (non hole) */
    666 		return (0);
    667 	}
    668 
    669 	/*
    670 	 * Calling bmap_read() one block at a time on a 1TB file takes forever,
    671 	 * so we use a special function to search for holes or blocks.
    672 	 */
    673 	if (cmd == _FIO_SEEK_HOLE)
    674 		hole = B_TRUE;
    675 	else
    676 		hole = B_FALSE;
    677 	error = bmap_find(ip, hole, &noff);
    678 	rw_exit(&ip->i_contents);
    679 
    680 	/* end of file? */
    681 	if (error == ENXIO) {
    682 		/*
    683 		 * Handle the virtual hole at the end of file.
    684 		 */
    685 		if (cmd == _FIO_SEEK_HOLE) {
    686 			*off = isz;
    687 			return (0);
    688 		}
    689 		return (ENXIO);
    690 	}
    691 	if (noff < *off)
    692 		return (error);
    693 	*off = noff;
    694 	return (error);
    695 }
    696 
    697 int
    698 ufs_mark_compressed(struct vnode *vp)
    699 {
    700 	struct inode *ip = VTOI(vp);
    701 	struct ufsvfs *ufsvfsp = ip->i_ufsvfs;
    702 
    703 	if (vp->v_type != VREG)
    704 		return (EINVAL);
    705 
    706 	rw_enter(&ip->i_contents, RW_WRITER);
    707 	ip->i_cflags |= ICOMPRESS;
    708 	TRANS_INODE(ufsvfsp, ip);
    709 	ip->i_flag |= (ICHG|ISEQ);
    710 	ip->i_seq++;
    711 	if (!TRANS_ISTRANS(ufsvfsp))
    712 		ufs_iupdat(ip, I_ASYNC);
    713 	rw_exit(&ip->i_contents);
    714 
    715 	return (0);
    716 }
    717