[deliverable/linux.git] / fs / xfs / xfs_rw.c

/*
 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_itable.h"
#include "xfs_btree.h"
#include "xfs_alloc.h"
#include "xfs_ialloc.h"
#include "xfs_attr.h"
#include "xfs_bmap.h"
#include "xfs_acl.h"
#include "xfs_mac.h"
#include "xfs_error.h"
#include "xfs_buf_item.h"
#include "xfs_rw.h"

/*
 * This is a subroutine for xfs_write() and other writers (xfs_ioctl)
 * which clears the setuid and setgid bits when a file is written.
 */
int
xfs_write_clear_setuid(
	xfs_inode_t	*ip)
{
	xfs_mount_t	*mp;
	xfs_trans_t	*tp;
	int		error;

	mp = ip->i_mount;
	tp = xfs_trans_alloc(mp, XFS_TRANS_WRITEID);
	if ((error = xfs_trans_reserve(tp, 0,
				      XFS_WRITEID_LOG_RES(mp),
				      0, 0, 0))) {
		xfs_trans_cancel(tp, 0);
		return error;
	}
	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
	xfs_trans_ihold(tp, ip);
	ip->i_d.di_mode &= ~S_ISUID;

	/*
	 * Note that we don't have to worry about mandatory
	 * file locking being disabled here because we only
	 * clear the S_ISGID bit if the Group execute bit is
	 * on, but if it was on then mandatory locking wouldn't
	 * have been enabled.
	 */
	if (ip->i_d.di_mode & S_IXGRP) {
		ip->i_d.di_mode &= ~S_ISGID;
	}
	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
	xfs_trans_set_sync(tp);
	error = xfs_trans_commit(tp, 0, NULL);
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	return 0;
}

/*
 * Force a shutdown of the filesystem instantly while keeping
 * the filesystem consistent. We don't do an unmount here; just shutdown
 * the shop, make sure that absolutely nothing persistent happens to
 * this filesystem after this point.
 */

void
xfs_do_force_shutdown(
	bhv_desc_t	*bdp,
	int		flags,
	char		*fname,
	int		lnnum)
{
	int		logerror;
	xfs_mount_t	*mp;

	mp = XFS_BHVTOM(bdp);
	logerror = flags & SHUTDOWN_LOG_IO_ERROR;

	if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
		cmn_err(CE_NOTE, "xfs_force_shutdown(%s,0x%x) called from "
				 "line %d of file %s.  Return address = 0x%p",
			mp->m_fsname, flags, lnnum, fname, __return_address);
	}
	/*
	 * No need to duplicate efforts.
	 */
	if (XFS_FORCED_SHUTDOWN(mp) && !logerror)
		return;

	/*
	 * This flags XFS_MOUNT_FS_SHUTDOWN, makes sure that we don't
	 * queue up anybody new on the log reservations, and wakes up
	 * everybody who's sleeping on log reservations to tell them
	 * the bad news.
	 */
	if (xfs_log_force_umount(mp, logerror))
		return;

	if (flags & SHUTDOWN_CORRUPT_INCORE) {
		xfs_cmn_err(XFS_PTAG_SHUTDOWN_CORRUPT, CE_ALERT, mp,
    "Corruption of in-memory data detected.  Shutting down filesystem: %s",
			mp->m_fsname);
		if (XFS_ERRLEVEL_HIGH <= xfs_error_level) {
			xfs_stack_trace();
		}
	} else if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
		if (logerror) {
			xfs_cmn_err(XFS_PTAG_SHUTDOWN_LOGERROR, CE_ALERT, mp,
		"Log I/O Error Detected.  Shutting down filesystem: %s",
				mp->m_fsname);
		} else if (flags & SHUTDOWN_DEVICE_REQ) {
			xfs_cmn_err(XFS_PTAG_SHUTDOWN_IOERROR, CE_ALERT, mp,
		"All device paths lost.  Shutting down filesystem: %s",
				mp->m_fsname);
		} else if (!(flags & SHUTDOWN_REMOTE_REQ)) {
			xfs_cmn_err(XFS_PTAG_SHUTDOWN_IOERROR, CE_ALERT, mp,
		"I/O Error Detected.  Shutting down filesystem: %s",
				mp->m_fsname);
		}
	}
	if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
		cmn_err(CE_ALERT, "Please umount the filesystem, "
				  "and rectify the problem(s)");
	}
}


/*
 * Called when we want to stop a buffer from getting written or read.
 * We attach the EIO error, muck with its flags, and call biodone
 * so that the proper iodone callbacks get called.
 */
int
xfs_bioerror(
	xfs_buf_t *bp)
{

#ifdef XFSERRORDEBUG
	ASSERT(XFS_BUF_ISREAD(bp) || bp->b_iodone);
#endif

	/*
	 * No need to wait until the buffer is unpinned.
	 * We aren't flushing it.
	 */
	xfs_buftrace("XFS IOERROR", bp);
	XFS_BUF_ERROR(bp, EIO);
	/*
	 * We're calling biodone, so delete B_DONE flag. Either way
	 * we have to call the iodone callback, and calling biodone
	 * probably is the best way since it takes care of
	 * GRIO as well.
	 */
	XFS_BUF_UNREAD(bp);
	XFS_BUF_UNDELAYWRITE(bp);
	XFS_BUF_UNDONE(bp);
	XFS_BUF_STALE(bp);

	XFS_BUF_CLR_BDSTRAT_FUNC(bp);
	xfs_biodone(bp);

	return (EIO);
}

/*
 * Same as xfs_bioerror, except that we are releasing the buffer
 * here ourselves, and avoiding the biodone call.
 * This is meant for userdata errors; metadata bufs come with
 * iodone functions attached, so that we can track down errors.
 */
int
xfs_bioerror_relse(
	xfs_buf_t *bp)
{
	int64_t fl;

	ASSERT(XFS_BUF_IODONE_FUNC(bp) != xfs_buf_iodone_callbacks);
	ASSERT(XFS_BUF_IODONE_FUNC(bp) != xlog_iodone);

	xfs_buftrace("XFS IOERRELSE", bp);
	fl = XFS_BUF_BFLAGS(bp);
	/*
	 * No need to wait until the buffer is unpinned.
	 * We aren't flushing it.
	 *
	 * chunkhold expects B_DONE to be set, whether
	 * we actually finish the I/O or not. We don't want to
	 * change that interface.
	 */
	XFS_BUF_UNREAD(bp);
	XFS_BUF_UNDELAYWRITE(bp);
	XFS_BUF_DONE(bp);
	XFS_BUF_STALE(bp);
	XFS_BUF_CLR_IODONE_FUNC(bp);
	XFS_BUF_CLR_BDSTRAT_FUNC(bp);
	if (!(fl & XFS_B_ASYNC)) {
		/*
		 * Mark b_error and B_ERROR _both_.
		 * Lot's of chunkcache code assumes that.
		 * There's no reason to mark error for
		 * ASYNC buffers.
		 */
		XFS_BUF_ERROR(bp, EIO);
		XFS_BUF_V_IODONESEMA(bp);
	} else {
		xfs_buf_relse(bp);
	}
	return (EIO);
}

/*
 * Prints out an ALERT message about I/O error.
 */
void
xfs_ioerror_alert(
	char			*func,
	struct xfs_mount	*mp,
	xfs_buf_t		*bp,
	xfs_daddr_t		blkno)
{
	cmn_err(CE_ALERT,
 "I/O error in filesystem (\"%s\") meta-data dev %s block 0x%llx"
 "       (\"%s\") error %d buf count %zd",
		(!mp || !mp->m_fsname) ? "(fs name not set)" : mp->m_fsname,
		XFS_BUFTARG_NAME(XFS_BUF_TARGET(bp)),
		(__uint64_t)blkno, func,
		XFS_BUF_GETERROR(bp), XFS_BUF_COUNT(bp));
}

/*
 * This isn't an absolute requirement, but it is
 * just a good idea to call xfs_read_buf instead of
 * directly doing a read_buf call. For one, we shouldn't
 * be doing this disk read if we are in SHUTDOWN state anyway,
 * so this stops that from happening. Secondly, this does all
 * the error checking stuff and the brelse if appropriate for
 * the caller, so the code can be a little leaner.
 */

int
xfs_read_buf(
	struct xfs_mount *mp,
	xfs_buftarg_t	 *target,
	xfs_daddr_t	 blkno,
	int              len,
	uint             flags,
	xfs_buf_t	 **bpp)
{
	xfs_buf_t	 *bp;
	int		 error;

	if (flags)
		bp = xfs_buf_read_flags(target, blkno, len, flags);
	else
		bp = xfs_buf_read(target, blkno, len, flags);
	if (!bp)
		return XFS_ERROR(EIO);
	error = XFS_BUF_GETERROR(bp);
	if (bp && !error && !XFS_FORCED_SHUTDOWN(mp)) {
		*bpp = bp;
	} else {
		*bpp = NULL;
		if (error) {
			xfs_ioerror_alert("xfs_read_buf", mp, bp, XFS_BUF_ADDR(bp));
		} else {
			error = XFS_ERROR(EIO);
		}
		if (bp) {
			XFS_BUF_UNDONE(bp);
			XFS_BUF_UNDELAYWRITE(bp);
			XFS_BUF_STALE(bp);
			/*
			 * brelse clears B_ERROR and b_error
			 */
			xfs_buf_relse(bp);
		}
	}
	return (error);
}

/*
 * Wrapper around bwrite() so that we can trap
 * write errors, and act accordingly.
 */
int
xfs_bwrite(
	struct xfs_mount *mp,
	struct xfs_buf	 *bp)
{
	int	error;

	/*
	 * XXXsup how does this work for quotas.
	 */
	XFS_BUF_SET_BDSTRAT_FUNC(bp, xfs_bdstrat_cb);
	XFS_BUF_SET_FSPRIVATE3(bp, mp);
	XFS_BUF_WRITE(bp);

	if ((error = XFS_bwrite(bp))) {
		ASSERT(mp);
		/*
		 * Cannot put a buftrace here since if the buffer is not
		 * B_HOLD then we will brelse() the buffer before returning
		 * from bwrite and we could be tracing a buffer that has
		 * been reused.
		 */
		xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
	}
	return (error);
}
Commit	Line	Data
1da177e4	1	/*
7b718769 NS	2	* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
7b718769 NS	3	* All Rights Reserved.
1da177e4	4	*
7b718769 NS	5	* This program is free software; you can redistribute it and/or
7b718769 NS	6	* modify it under the terms of the GNU General Public License as
1da177e4 LT	7	* published by the Free Software Foundation.
1da177e4 LT	8	*
7b718769 NS	9	* This program is distributed in the hope that it would be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
1da177e4	13	*
7b718769 NS	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write the Free Software Foundation,
	16	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
1da177e4	17	*/
1da177e4	18	#include "xfs.h"
a844f451	19	#include "xfs_fs.h"
1da177e4	20	#include "xfs_types.h"
a844f451	21	#include "xfs_bit.h"
1da177e4	22	#include "xfs_log.h"
a844f451	23	#include "xfs_inum.h"
1da177e4 LT	24	#include "xfs_trans.h"
	25	#include "xfs_sb.h"
	26	#include "xfs_ag.h"
	27	#include "xfs_dir.h"
	28	#include "xfs_dir2.h"
	29	#include "xfs_dmapi.h"
	30	#include "xfs_mount.h"
1da177e4	31	#include "xfs_bmap_btree.h"
a844f451	32	#include "xfs_alloc_btree.h"
1da177e4	33	#include "xfs_ialloc_btree.h"
a844f451 NS	34	#include "xfs_dir_sf.h"
	35	#include "xfs_dir2_sf.h"
	36	#include "xfs_attr_sf.h"
	37	#include "xfs_dinode.h"
	38	#include "xfs_inode.h"
	39	#include "xfs_inode_item.h"
1da177e4 LT	40	#include "xfs_itable.h"
	41	#include "xfs_btree.h"
	42	#include "xfs_alloc.h"
	43	#include "xfs_ialloc.h"
	44	#include "xfs_attr.h"
1da177e4 LT	45	#include "xfs_bmap.h"
	46	#include "xfs_acl.h"
	47	#include "xfs_mac.h"
	48	#include "xfs_error.h"
	49	#include "xfs_buf_item.h"
	50	#include "xfs_rw.h"
	51
	52	/*
	53	* This is a subroutine for xfs_write() and other writers (xfs_ioctl)
	54	* which clears the setuid and setgid bits when a file is written.
	55	*/
	56	int
	57	xfs_write_clear_setuid(
	58	xfs_inode_t *ip)
	59	{
	60	xfs_mount_t *mp;
	61	xfs_trans_t *tp;
	62	int error;
	63
	64	mp = ip->i_mount;
	65	tp = xfs_trans_alloc(mp, XFS_TRANS_WRITEID);
	66	if ((error = xfs_trans_reserve(tp, 0,
	67	XFS_WRITEID_LOG_RES(mp),
	68	0, 0, 0))) {
	69	xfs_trans_cancel(tp, 0);
	70	return error;
	71	}
	72	xfs_ilock(ip, XFS_ILOCK_EXCL);
	73	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
	74	xfs_trans_ihold(tp, ip);
	75	ip->i_d.di_mode &= ~S_ISUID;
	76
	77	/*
	78	* Note that we don't have to worry about mandatory
	79	* file locking being disabled here because we only
	80	* clear the S_ISGID bit if the Group execute bit is
	81	* on, but if it was on then mandatory locking wouldn't
	82	* have been enabled.
	83	*/
	84	if (ip->i_d.di_mode & S_IXGRP) {
	85	ip->i_d.di_mode &= ~S_ISGID;
	86	}
	87	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
	88	xfs_trans_set_sync(tp);
	89	error = xfs_trans_commit(tp, 0, NULL);
	90	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	91	return 0;
	92	}
	93
	94	/*
	95	* Force a shutdown of the filesystem instantly while keeping
	96	* the filesystem consistent. We don't do an unmount here; just shutdown
	97	* the shop, make sure that absolutely nothing persistent happens to
	98	* this filesystem after this point.
	99	*/
	100
	101	void
	102	xfs_do_force_shutdown(
	103	bhv_desc_t *bdp,
	104	int flags,
	105	char *fname,
	106	int lnnum)
	107	{
	108	int logerror;
109	xfs_mount_t *mp;
110
111	mp = XFS_BHVTOM(bdp);
7d04a335	112	logerror = flags & SHUTDOWN_LOG_IO_ERROR;
1da177e4	113
7d04a335 NS	114	if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
	115	cmn_err(CE_NOTE, "xfs_force_shutdown(%s,0x%x) called from "
	116	"line %d of file %s. Return address = 0x%p",
	117	mp->m_fsname, flags, lnnum, fname, __return_address);
1da177e4 LT	118	}
	119	/*
	120	* No need to duplicate efforts.
	121	*/
	122	if (XFS_FORCED_SHUTDOWN(mp) && !logerror)
	123	return;
	124
	125	/*
	126	* This flags XFS_MOUNT_FS_SHUTDOWN, makes sure that we don't
	127	* queue up anybody new on the log reservations, and wakes up
7d04a335 NS	128	* everybody who's sleeping on log reservations to tell them
7d04a335 NS	129	* the bad news.
1da177e4 LT	130	*/
	131	if (xfs_log_force_umount(mp, logerror))
	132	return;
	133
7d04a335	134	if (flags & SHUTDOWN_CORRUPT_INCORE) {
1da177e4 LT	135	xfs_cmn_err(XFS_PTAG_SHUTDOWN_CORRUPT, CE_ALERT, mp,
	136	"Corruption of in-memory data detected. Shutting down filesystem: %s",
	137	mp->m_fsname);
	138	if (XFS_ERRLEVEL_HIGH <= xfs_error_level) {
	139	xfs_stack_trace();
	140	}
7d04a335	141	} else if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
1da177e4 LT	142	if (logerror) {
1da177e4 LT	143	xfs_cmn_err(XFS_PTAG_SHUTDOWN_LOGERROR, CE_ALERT, mp,
7d04a335	144	"Log I/O Error Detected. Shutting down filesystem: %s",
1da177e4	145	mp->m_fsname);
7d04a335	146	} else if (flags & SHUTDOWN_DEVICE_REQ) {
1da177e4	147	xfs_cmn_err(XFS_PTAG_SHUTDOWN_IOERROR, CE_ALERT, mp,
7d04a335 NS	148	"All device paths lost. Shutting down filesystem: %s",
	149	mp->m_fsname);
	150	} else if (!(flags & SHUTDOWN_REMOTE_REQ)) {
	151	xfs_cmn_err(XFS_PTAG_SHUTDOWN_IOERROR, CE_ALERT, mp,
	152	"I/O Error Detected. Shutting down filesystem: %s",
1da177e4 LT	153	mp->m_fsname);
	154	}
	155	}
7d04a335 NS	156	if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
	157	cmn_err(CE_ALERT, "Please umount the filesystem, "
	158	"and rectify the problem(s)");
1da177e4 LT	159	}
	160	}
	161
	162
	163	/*
	164	* Called when we want to stop a buffer from getting written or read.
	165	* We attach the EIO error, muck with its flags, and call biodone
	166	* so that the proper iodone callbacks get called.
	167	*/
	168	int
	169	xfs_bioerror(
	170	xfs_buf_t *bp)
	171	{
	172
	173	#ifdef XFSERRORDEBUG
	174	ASSERT(XFS_BUF_ISREAD(bp) \|\| bp->b_iodone);
	175	#endif
	176
	177	/*
	178	* No need to wait until the buffer is unpinned.
	179	* We aren't flushing it.
	180	*/
	181	xfs_buftrace("XFS IOERROR", bp);
	182	XFS_BUF_ERROR(bp, EIO);
	183	/*
	184	* We're calling biodone, so delete B_DONE flag. Either way
	185	* we have to call the iodone callback, and calling biodone
	186	* probably is the best way since it takes care of
	187	* GRIO as well.
	188	*/
	189	XFS_BUF_UNREAD(bp);
	190	XFS_BUF_UNDELAYWRITE(bp);
	191	XFS_BUF_UNDONE(bp);
	192	XFS_BUF_STALE(bp);
	193
	194	XFS_BUF_CLR_BDSTRAT_FUNC(bp);
	195	xfs_biodone(bp);
	196
	197	return (EIO);
	198	}
	199
	200	/*
	201	* Same as xfs_bioerror, except that we are releasing the buffer
	202	* here ourselves, and avoiding the biodone call.
	203	* This is meant for userdata errors; metadata bufs come with
	204	* iodone functions attached, so that we can track down errors.
	205	*/
	206	int
	207	xfs_bioerror_relse(
	208	xfs_buf_t *bp)
	209	{
	210	int64_t fl;
	211
	212	ASSERT(XFS_BUF_IODONE_FUNC(bp) != xfs_buf_iodone_callbacks);
	213	ASSERT(XFS_BUF_IODONE_FUNC(bp) != xlog_iodone);
	214
	215	xfs_buftrace("XFS IOERRELSE", bp);
	216	fl = XFS_BUF_BFLAGS(bp);
	217	/*
	218	* No need to wait until the buffer is unpinned.
	219	* We aren't flushing it.
	220	*
	221	* chunkhold expects B_DONE to be set, whether
	222	* we actually finish the I/O or not. We don't want to
223	* change that interface.
224	*/
225	XFS_BUF_UNREAD(bp);
226	XFS_BUF_UNDELAYWRITE(bp);
227	XFS_BUF_DONE(bp);
228	XFS_BUF_STALE(bp);
229	XFS_BUF_CLR_IODONE_FUNC(bp);
230	XFS_BUF_CLR_BDSTRAT_FUNC(bp);
231	if (!(fl & XFS_B_ASYNC)) {
232	/*
233	* Mark b_error and B_ERROR _both_.
234	* Lot's of chunkcache code assumes that.
235	* There's no reason to mark error for
236	* ASYNC buffers.
237	*/
238	XFS_BUF_ERROR(bp, EIO);
239	XFS_BUF_V_IODONESEMA(bp);
240	} else {
241	xfs_buf_relse(bp);
242	}
243	return (EIO);
244	}
ce8e922c	245
1da177e4 LT	246	/*
	247	* Prints out an ALERT message about I/O error.
	248	*/
	249	void
	250	xfs_ioerror_alert(
	251	char *func,
	252	struct xfs_mount *mp,
	253	xfs_buf_t *bp,
	254	xfs_daddr_t blkno)
	255	{
	256	cmn_err(CE_ALERT,
	257	"I/O error in filesystem (\"%s\") meta-data dev %s block 0x%llx"
da1650a5	258	" (\"%s\") error %d buf count %zd",
1da177e4	259	(!mp \|\| !mp->m_fsname) ? "(fs name not set)" : mp->m_fsname,
ce8e922c NS	260	XFS_BUFTARG_NAME(XFS_BUF_TARGET(bp)),
	261	(__uint64_t)blkno, func,
	262	XFS_BUF_GETERROR(bp), XFS_BUF_COUNT(bp));
1da177e4 LT	263	}
	264
	265	/*
	266	* This isn't an absolute requirement, but it is
	267	* just a good idea to call xfs_read_buf instead of
	268	* directly doing a read_buf call. For one, we shouldn't
	269	* be doing this disk read if we are in SHUTDOWN state anyway,
	270	* so this stops that from happening. Secondly, this does all
	271	* the error checking stuff and the brelse if appropriate for
	272	* the caller, so the code can be a little leaner.
	273	*/
	274
	275	int
	276	xfs_read_buf(
	277	struct xfs_mount *mp,
	278	xfs_buftarg_t *target,
	279	xfs_daddr_t blkno,
	280	int len,
	281	uint flags,
	282	xfs_buf_t **bpp)
	283	{
	284	xfs_buf_t *bp;
	285	int error;
	286
	287	if (flags)
	288	bp = xfs_buf_read_flags(target, blkno, len, flags);
	289	else
	290	bp = xfs_buf_read(target, blkno, len, flags);
	291	if (!bp)
	292	return XFS_ERROR(EIO);
	293	error = XFS_BUF_GETERROR(bp);
	294	if (bp && !error && !XFS_FORCED_SHUTDOWN(mp)) {
	295	*bpp = bp;
	296	} else {
	297	*bpp = NULL;
	298	if (error) {
	299	xfs_ioerror_alert("xfs_read_buf", mp, bp, XFS_BUF_ADDR(bp));
	300	} else {
	301	error = XFS_ERROR(EIO);
	302	}
	303	if (bp) {
	304	XFS_BUF_UNDONE(bp);
	305	XFS_BUF_UNDELAYWRITE(bp);
	306	XFS_BUF_STALE(bp);
	307	/*
	308	* brelse clears B_ERROR and b_error
	309	*/
	310	xfs_buf_relse(bp);
	311	}
	312	}
	313	return (error);
	314	}
	315
	316	/*
	317	* Wrapper around bwrite() so that we can trap
	318	* write errors, and act accordingly.
	319	*/
	320	int
	321	xfs_bwrite(
	322	struct xfs_mount *mp,
	323	struct xfs_buf *bp)
	324	{
	325	int error;
	326
327	/*
328	* XXXsup how does this work for quotas.
329	*/
330	XFS_BUF_SET_BDSTRAT_FUNC(bp, xfs_bdstrat_cb);
331	XFS_BUF_SET_FSPRIVATE3(bp, mp);
332	XFS_BUF_WRITE(bp);
333
334	if ((error = XFS_bwrite(bp))) {
335	ASSERT(mp);
336	/*
337	* Cannot put a buftrace here since if the buffer is not
338	* B_HOLD then we will brelse() the buffer before returning
339	* from bwrite and we could be tracing a buffer that has
340	* been reused.
341	*/
7d04a335	342	xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
1da177e4 LT	343	}
	344	return (error);
	345	}