/*

   * 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_acl.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);

  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
  	return 0;
  }
  
  /*

   * Handle logging requirements of various synchronous types of write.
   */
  int
  xfs_write_sync_logforce(
  	xfs_mount_t	*mp,
  	xfs_inode_t	*ip)
  {
  	int		error = 0;
  
  	/*
  	 * If we're treating this as O_DSYNC and we have not updated the
  	 * size, force the log.
  	 */
  	if (!(mp->m_flags & XFS_MOUNT_OSYNCISOSYNC) &&
  	    !(ip->i_update_size)) {
  		xfs_inode_log_item_t	*iip = ip->i_itemp;
  
  		/*
  		 * If an allocation transaction occurred
  		 * without extending the size, then we have to force
  		 * the log up the proper point to ensure that the
  		 * allocation is permanent.  We can't count on
  		 * the fact that buffered writes lock out direct I/O
  		 * writes - the direct I/O write could have extended
  		 * the size nontransactionally, then finished before
  		 * we started.  xfs_write_file will think that the file
  		 * didn't grow but the update isn't safe unless the
  		 * size change is logged.
  		 *
  		 * Force the log if we've committed a transaction
  		 * against the inode or if someone else has and
  		 * the commit record hasn't gone to disk (e.g.
  		 * the inode is pinned).  This guarantees that
  		 * all changes affecting the inode are permanent
  		 * when we return.
  		 */
  		if (iip && iip->ili_last_lsn) {
  			xfs_log_force(mp, iip->ili_last_lsn,
  					XFS_LOG_FORCE | XFS_LOG_SYNC);
  		} else if (xfs_ipincount(ip) > 0) {
  			xfs_log_force(mp, (xfs_lsn_t)0,
  					XFS_LOG_FORCE | XFS_LOG_SYNC);
  		}
  
  	} else {
  		xfs_trans_t	*tp;
  
  		/*
  		 * O_SYNC or O_DSYNC _with_ a size update are handled
  		 * the same way.
  		 *
  		 * If the write was synchronous then we need to make
  		 * sure that the inode modification time is permanent.
  		 * We'll have updated the timestamp above, so here
  		 * we use a synchronous transaction to log the inode.
  		 * It's not fast, but it's necessary.
  		 *
  		 * If this a dsync write and the size got changed
  		 * non-transactionally, then we need to ensure that
  		 * the size change gets logged in a synchronous
  		 * transaction.
  		 */
  		tp = xfs_trans_alloc(mp, XFS_TRANS_WRITE_SYNC);
  		if ((error = xfs_trans_reserve(tp, 0,
  						XFS_SWRITE_LOG_RES(mp),
  						0, 0, 0))) {
  			/* Transaction reserve failed */
  			xfs_trans_cancel(tp, 0);
  		} else {
  			/* Transaction reserve successful */
  			xfs_ilock(ip, XFS_ILOCK_EXCL);
  			xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
  			xfs_trans_ihold(tp, ip);
  			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 error;
  }
  
  /*

   * 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);
  }