[linux-2.6-block.git] / fs / xfs / xfs_rw.c

/*
 * Copyright (c) 2000-2006 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_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_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_error.h"
#include "xfs_buf_item.h"
#include "xfs_rw.h"
#include "xfs_trace.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);
	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(
	xfs_mount_t	*mp,
	int		flags,
	char		*fname,
	int		lnnum)
{
	int		logerror;

	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_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);

	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_FINISH_IOWAIT(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)
		flags = XBF_LOCK | XBF_MAPPED;

	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);
	bp->b_mount = 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);
}

/*
 * helper function to extract extent size hint from inode
 */
xfs_extlen_t
xfs_get_extsz_hint(
	struct xfs_inode	*ip)
{
	xfs_extlen_t		extsz;

	if (unlikely(XFS_IS_REALTIME_INODE(ip))) {
		extsz = (ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE)
				? ip->i_d.di_extsize
				: ip->i_mount->m_sb.sb_rextsize;
		ASSERT(extsz);
	} else {
		extsz = (ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE)
				? ip->i_d.di_extsize : 0;
	}

	return extsz;
}
Commit	Line	Data
1da177e4	1	/*
1e69dd0e	2	* Copyright (c) 2000-2006 Silicon Graphics, Inc.
7b718769	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"
1da177e4 LT	27	#include "xfs_dir2.h"
	28	#include "xfs_dmapi.h"
	29	#include "xfs_mount.h"
1da177e4	30	#include "xfs_bmap_btree.h"
a844f451	31	#include "xfs_alloc_btree.h"
1da177e4	32	#include "xfs_ialloc_btree.h"
a844f451 NS	33	#include "xfs_dir2_sf.h"
	34	#include "xfs_attr_sf.h"
	35	#include "xfs_dinode.h"
	36	#include "xfs_inode.h"
	37	#include "xfs_inode_item.h"
1da177e4 LT	38	#include "xfs_itable.h"
	39	#include "xfs_btree.h"
	40	#include "xfs_alloc.h"
	41	#include "xfs_ialloc.h"
	42	#include "xfs_attr.h"
1da177e4	43	#include "xfs_bmap.h"
1da177e4 LT	44	#include "xfs_error.h"
	45	#include "xfs_buf_item.h"
	46	#include "xfs_rw.h"
0b1b213f	47	#include "xfs_trace.h"
1da177e4 LT	48
	49	/*
	50	* This is a subroutine for xfs_write() and other writers (xfs_ioctl)
	51	* which clears the setuid and setgid bits when a file is written.
	52	*/
	53	int
	54	xfs_write_clear_setuid(
	55	xfs_inode_t *ip)
	56	{
	57	xfs_mount_t *mp;
	58	xfs_trans_t *tp;
	59	int error;
	60
	61	mp = ip->i_mount;
	62	tp = xfs_trans_alloc(mp, XFS_TRANS_WRITEID);
	63	if ((error = xfs_trans_reserve(tp, 0,
	64	XFS_WRITEID_LOG_RES(mp),
	65	0, 0, 0))) {
	66	xfs_trans_cancel(tp, 0);
	67	return error;
	68	}
	69	xfs_ilock(ip, XFS_ILOCK_EXCL);
	70	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
	71	xfs_trans_ihold(tp, ip);
	72	ip->i_d.di_mode &= ~S_ISUID;
	73
	74	/*
	75	* Note that we don't have to worry about mandatory
	76	* file locking being disabled here because we only
	77	* clear the S_ISGID bit if the Group execute bit is
	78	* on, but if it was on then mandatory locking wouldn't
	79	* have been enabled.
	80	*/
	81	if (ip->i_d.di_mode & S_IXGRP) {
	82	ip->i_d.di_mode &= ~S_ISGID;
	83	}
	84	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
	85	xfs_trans_set_sync(tp);
1c72bf90	86	error = xfs_trans_commit(tp, 0);
1da177e4 LT	87	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	88	return 0;
	89	}
	90
	91	/*
	92	* Force a shutdown of the filesystem instantly while keeping
	93	* the filesystem consistent. We don't do an unmount here; just shutdown
	94	* the shop, make sure that absolutely nothing persistent happens to
	95	* this filesystem after this point.
	96	*/
1da177e4 LT	97	void
1da177e4 LT	98	xfs_do_force_shutdown(
48c872a9	99	xfs_mount_t *mp,
1da177e4 LT	100	int flags,
	101	char *fname,
	102	int lnnum)
	103	{
	104	int logerror;
1da177e4	105
7d04a335	106	logerror = flags & SHUTDOWN_LOG_IO_ERROR;
1da177e4	107
7d04a335 NS	108	if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
	109	cmn_err(CE_NOTE, "xfs_force_shutdown(%s,0x%x) called from "
	110	"line %d of file %s. Return address = 0x%p",
	111	mp->m_fsname, flags, lnnum, fname, __return_address);
1da177e4 LT	112	}
	113	/*
	114	* No need to duplicate efforts.
	115	*/
	116	if (XFS_FORCED_SHUTDOWN(mp) && !logerror)
	117	return;
	118
	119	/*
	120	* This flags XFS_MOUNT_FS_SHUTDOWN, makes sure that we don't
	121	* queue up anybody new on the log reservations, and wakes up
7d04a335 NS	122	* everybody who's sleeping on log reservations to tell them
7d04a335 NS	123	* the bad news.
1da177e4 LT	124	*/
	125	if (xfs_log_force_umount(mp, logerror))
	126	return;
	127
7d04a335	128	if (flags & SHUTDOWN_CORRUPT_INCORE) {
1da177e4 LT	129	xfs_cmn_err(XFS_PTAG_SHUTDOWN_CORRUPT, CE_ALERT, mp,
	130	"Corruption of in-memory data detected. Shutting down filesystem: %s",
	131	mp->m_fsname);
	132	if (XFS_ERRLEVEL_HIGH <= xfs_error_level) {
	133	xfs_stack_trace();
	134	}
7d04a335	135	} else if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
1da177e4 LT	136	if (logerror) {
1da177e4 LT	137	xfs_cmn_err(XFS_PTAG_SHUTDOWN_LOGERROR, CE_ALERT, mp,
7d04a335	138	"Log I/O Error Detected. Shutting down filesystem: %s",
1da177e4	139	mp->m_fsname);
7d04a335	140	} else if (flags & SHUTDOWN_DEVICE_REQ) {
1da177e4	141	xfs_cmn_err(XFS_PTAG_SHUTDOWN_IOERROR, CE_ALERT, mp,
7d04a335 NS	142	"All device paths lost. Shutting down filesystem: %s",
	143	mp->m_fsname);
	144	} else if (!(flags & SHUTDOWN_REMOTE_REQ)) {
	145	xfs_cmn_err(XFS_PTAG_SHUTDOWN_IOERROR, CE_ALERT, mp,
	146	"I/O Error Detected. Shutting down filesystem: %s",
1da177e4 LT	147	mp->m_fsname);
	148	}
	149	}
7d04a335 NS	150	if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
	151	cmn_err(CE_ALERT, "Please umount the filesystem, "
	152	"and rectify the problem(s)");
1da177e4 LT	153	}
	154	}
	155
	156
	157	/*
	158	* Called when we want to stop a buffer from getting written or read.
	159	* We attach the EIO error, muck with its flags, and call biodone
	160	* so that the proper iodone callbacks get called.
	161	*/
	162	int
	163	xfs_bioerror(
	164	xfs_buf_t *bp)
	165	{
	166
	167	#ifdef XFSERRORDEBUG
	168	ASSERT(XFS_BUF_ISREAD(bp) \|\| bp->b_iodone);
	169	#endif
	170
	171	/*
	172	* No need to wait until the buffer is unpinned.
	173	* We aren't flushing it.
	174	*/
1da177e4 LT	175	XFS_BUF_ERROR(bp, EIO);
	176	/*
	177	* We're calling biodone, so delete B_DONE flag. Either way
	178	* we have to call the iodone callback, and calling biodone
	179	* probably is the best way since it takes care of
	180	* GRIO as well.
	181	*/
	182	XFS_BUF_UNREAD(bp);
	183	XFS_BUF_UNDELAYWRITE(bp);
	184	XFS_BUF_UNDONE(bp);
	185	XFS_BUF_STALE(bp);
	186
	187	XFS_BUF_CLR_BDSTRAT_FUNC(bp);
	188	xfs_biodone(bp);
	189
	190	return (EIO);
	191	}
	192
	193	/*
	194	* Same as xfs_bioerror, except that we are releasing the buffer
	195	* here ourselves, and avoiding the biodone call.
	196	* This is meant for userdata errors; metadata bufs come with
	197	* iodone functions attached, so that we can track down errors.
	198	*/
	199	int
	200	xfs_bioerror_relse(
	201	xfs_buf_t *bp)
	202	{
	203	int64_t fl;
	204
	205	ASSERT(XFS_BUF_IODONE_FUNC(bp) != xfs_buf_iodone_callbacks);
	206	ASSERT(XFS_BUF_IODONE_FUNC(bp) != xlog_iodone);
	207
1da177e4 LT	208	fl = XFS_BUF_BFLAGS(bp);
	209	/*
	210	* No need to wait until the buffer is unpinned.
	211	* We aren't flushing it.
	212	*
	213	* chunkhold expects B_DONE to be set, whether
	214	* we actually finish the I/O or not. We don't want to
	215	* change that interface.
	216	*/
	217	XFS_BUF_UNREAD(bp);
	218	XFS_BUF_UNDELAYWRITE(bp);
	219	XFS_BUF_DONE(bp);
	220	XFS_BUF_STALE(bp);
	221	XFS_BUF_CLR_IODONE_FUNC(bp);
	222	XFS_BUF_CLR_BDSTRAT_FUNC(bp);
	223	if (!(fl & XFS_B_ASYNC)) {
	224	/*
	225	* Mark b_error and B_ERROR _both_.
	226	* Lot's of chunkcache code assumes that.
	227	* There's no reason to mark error for
	228	* ASYNC buffers.
	229	*/
	230	XFS_BUF_ERROR(bp, EIO);
b4dd330b	231	XFS_BUF_FINISH_IOWAIT(bp);
1da177e4 LT	232	} else {
	233	xfs_buf_relse(bp);
	234	}
	235	return (EIO);
	236	}
ce8e922c	237
1da177e4 LT	238	/*
	239	* Prints out an ALERT message about I/O error.
	240	*/
	241	void
	242	xfs_ioerror_alert(
	243	char *func,
	244	struct xfs_mount *mp,
	245	xfs_buf_t *bp,
	246	xfs_daddr_t blkno)
	247	{
	248	cmn_err(CE_ALERT,
	249	"I/O error in filesystem (\"%s\") meta-data dev %s block 0x%llx"
da1650a5	250	" (\"%s\") error %d buf count %zd",
1da177e4	251	(!mp \|\| !mp->m_fsname) ? "(fs name not set)" : mp->m_fsname,
ce8e922c NS	252	XFS_BUFTARG_NAME(XFS_BUF_TARGET(bp)),
	253	(__uint64_t)blkno, func,
	254	XFS_BUF_GETERROR(bp), XFS_BUF_COUNT(bp));
1da177e4 LT	255	}
	256
	257	/*
	258	* This isn't an absolute requirement, but it is
	259	* just a good idea to call xfs_read_buf instead of
	260	* directly doing a read_buf call. For one, we shouldn't
	261	* be doing this disk read if we are in SHUTDOWN state anyway,
	262	* so this stops that from happening. Secondly, this does all
	263	* the error checking stuff and the brelse if appropriate for
	264	* the caller, so the code can be a little leaner.
	265	*/
	266
	267	int
	268	xfs_read_buf(
	269	struct xfs_mount *mp,
	270	xfs_buftarg_t *target,
	271	xfs_daddr_t blkno,
	272	int len,
	273	uint flags,
	274	xfs_buf_t **bpp)
	275	{
	276	xfs_buf_t *bp;
	277	int error;
	278
6ad112bf CH	279	if (!flags)
	280	flags = XBF_LOCK \| XBF_MAPPED;
	281
	282	bp = xfs_buf_read(target, blkno, len, flags);
1da177e4 LT	283	if (!bp)
	284	return XFS_ERROR(EIO);
	285	error = XFS_BUF_GETERROR(bp);
	286	if (bp && !error && !XFS_FORCED_SHUTDOWN(mp)) {
	287	*bpp = bp;
	288	} else {
	289	*bpp = NULL;
	290	if (error) {
	291	xfs_ioerror_alert("xfs_read_buf", mp, bp, XFS_BUF_ADDR(bp));
	292	} else {
	293	error = XFS_ERROR(EIO);
	294	}
	295	if (bp) {
	296	XFS_BUF_UNDONE(bp);
	297	XFS_BUF_UNDELAYWRITE(bp);
	298	XFS_BUF_STALE(bp);
	299	/*
	300	* brelse clears B_ERROR and b_error
	301	*/
	302	xfs_buf_relse(bp);
	303	}
	304	}
	305	return (error);
	306	}
	307
	308	/*
	309	* Wrapper around bwrite() so that we can trap
	310	* write errors, and act accordingly.
	311	*/
	312	int
	313	xfs_bwrite(
	314	struct xfs_mount *mp,
	315	struct xfs_buf *bp)
	316	{
	317	int error;
	318
	319	/*
	320	* XXXsup how does this work for quotas.
	321	*/
	322	XFS_BUF_SET_BDSTRAT_FUNC(bp, xfs_bdstrat_cb);
15ac08a8	323	bp->b_mount = mp;
1da177e4 LT	324	XFS_BUF_WRITE(bp);
	325
	326	if ((error = XFS_bwrite(bp))) {
	327	ASSERT(mp);
	328	/*
	329	* Cannot put a buftrace here since if the buffer is not
	330	* B_HOLD then we will brelse() the buffer before returning
	331	* from bwrite and we could be tracing a buffer that has
	332	* been reused.
	333	*/
7d04a335	334	xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
1da177e4 LT	335	}
	336	return (error);
	337	}
5683f53e CH	338
	339	/*
	340	* helper function to extract extent size hint from inode
	341	*/
	342	xfs_extlen_t
	343	xfs_get_extsz_hint(
	344	struct xfs_inode *ip)
	345	{
	346	xfs_extlen_t extsz;
	347
	348	if (unlikely(XFS_IS_REALTIME_INODE(ip))) {
	349	extsz = (ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE)
	350	? ip->i_d.di_extsize
	351	: ip->i_mount->m_sb.sb_rextsize;
	352	ASSERT(extsz);
	353	} else {
	354	extsz = (ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE)
	355	? ip->i_d.di_extsize : 0;
	356	}
	357
	358	return extsz;
	359	}