/*
   * Copyright (c) 2000-2005 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_shared.h"
  #include "xfs_format.h"
  #include "xfs_log_format.h"
  #include "xfs_trans_resv.h"
  #include "xfs_sb.h"
  #include "xfs_ag.h"
  #include "xfs_mount.h"
  #include "xfs_inode.h"
  #include "xfs_trans.h"
  #include "xfs_inode_item.h"
  #include "xfs_error.h"
  #include "xfs_btree.h"
  #include "xfs_alloc_btree.h"
  #include "xfs_alloc.h"
  #include "xfs_ialloc.h"
  #include "xfs_fsops.h"
  #include "xfs_itable.h"
  #include "xfs_trans_space.h"
  #include "xfs_rtalloc.h"
  #include "xfs_trace.h"
  #include "xfs_log.h"
  #include "xfs_dinode.h"
  #include "xfs_filestream.h"
  
  /*
   * File system operations
   */
  
  int
  xfs_fs_geometry(
  	xfs_mount_t		*mp,
  	xfs_fsop_geom_t		*geo,
  	int			new_version)
  {
  
  	memset(geo, 0, sizeof(*geo));
  
  	geo->blocksize = mp->m_sb.sb_blocksize;
  	geo->rtextsize = mp->m_sb.sb_rextsize;
  	geo->agblocks = mp->m_sb.sb_agblocks;
  	geo->agcount = mp->m_sb.sb_agcount;
  	geo->logblocks = mp->m_sb.sb_logblocks;
  	geo->sectsize = mp->m_sb.sb_sectsize;
  	geo->inodesize = mp->m_sb.sb_inodesize;
  	geo->imaxpct = mp->m_sb.sb_imax_pct;
  	geo->datablocks = mp->m_sb.sb_dblocks;
  	geo->rtblocks = mp->m_sb.sb_rblocks;
  	geo->rtextents = mp->m_sb.sb_rextents;
  	geo->logstart = mp->m_sb.sb_logstart;
  	ASSERT(sizeof(geo->uuid)==sizeof(mp->m_sb.sb_uuid));
  	memcpy(geo->uuid, &mp->m_sb.sb_uuid, sizeof(mp->m_sb.sb_uuid));
  	if (new_version >= 2) {
  		geo->sunit = mp->m_sb.sb_unit;
  		geo->swidth = mp->m_sb.sb_width;
  	}
  	if (new_version >= 3) {
  		geo->version = XFS_FSOP_GEOM_VERSION;
  		geo->flags =
  			(xfs_sb_version_hasattr(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_ATTR : 0) |
  			(xfs_sb_version_hasnlink(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_NLINK : 0) |
  			(xfs_sb_version_hasquota(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_QUOTA : 0) |
  			(xfs_sb_version_hasalign(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_IALIGN : 0) |
  			(xfs_sb_version_hasdalign(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_DALIGN : 0) |
  			(xfs_sb_version_hasshared(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_SHARED : 0) |
  			(xfs_sb_version_hasextflgbit(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_EXTFLG : 0) |
  			(xfs_sb_version_hasdirv2(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_DIRV2 : 0) |
  			(xfs_sb_version_hassector(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_SECTOR : 0) |
  			(xfs_sb_version_hasasciici(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_DIRV2CI : 0) |
  			(xfs_sb_version_haslazysbcount(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_LAZYSB : 0) |
  			(xfs_sb_version_hasattr2(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_ATTR2 : 0) |
  			(xfs_sb_version_hasprojid32bit(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_PROJID32 : 0) |
  			(xfs_sb_version_hascrc(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_V5SB : 0) |
  			(xfs_sb_version_hasftype(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_FTYPE : 0);
  		geo->logsectsize = xfs_sb_version_hassector(&mp->m_sb) ?
  				mp->m_sb.sb_logsectsize : BBSIZE;
  		geo->rtsectsize = mp->m_sb.sb_blocksize;
  		geo->dirblocksize = mp->m_dirblksize;
  	}
  	if (new_version >= 4) {
  		geo->flags |=
  			(xfs_sb_version_haslogv2(&mp->m_sb) ?
  				XFS_FSOP_GEOM_FLAGS_LOGV2 : 0);
  		geo->logsunit = mp->m_sb.sb_logsunit;
  	}
  	return 0;
  }
  
  static struct xfs_buf *
  xfs_growfs_get_hdr_buf(
  	struct xfs_mount	*mp,
  	xfs_daddr_t		blkno,
  	size_t			numblks,
  	int			flags,
  	const struct xfs_buf_ops *ops)
  {
  	struct xfs_buf		*bp;
  
  	bp = xfs_buf_get_uncached(mp->m_ddev_targp, numblks, flags);
  	if (!bp)
  		return NULL;
  
  	xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
  	bp->b_bn = blkno;
  	bp->b_maps[0].bm_bn = blkno;
  	bp->b_ops = ops;
  
  	return bp;
  }
  
  static int
  xfs_growfs_data_private(
  	xfs_mount_t		*mp,		/* mount point for filesystem */
  	xfs_growfs_data_t	*in)		/* growfs data input struct */
  {
  	xfs_agf_t		*agf;
  	struct xfs_agfl		*agfl;
  	xfs_agi_t		*agi;
  	xfs_agnumber_t		agno;
  	xfs_extlen_t		agsize;
  	xfs_extlen_t		tmpsize;
  	xfs_alloc_rec_t		*arec;
  	xfs_buf_t		*bp;
  	int			bucket;
  	int			dpct;
  	int			error, saved_error = 0;
  	xfs_agnumber_t		nagcount;
  	xfs_agnumber_t		nagimax = 0;
  	xfs_rfsblock_t		nb, nb_mod;
  	xfs_rfsblock_t		new;
  	xfs_rfsblock_t		nfree;
  	xfs_agnumber_t		oagcount;
  	int			pct;
  	xfs_trans_t		*tp;
  
  	nb = in->newblocks;
  	pct = in->imaxpct;
  	if (nb < mp->m_sb.sb_dblocks || pct < 0 || pct > 100)
  		return XFS_ERROR(EINVAL);
  	if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
  		return error;
  	dpct = pct - mp->m_sb.sb_imax_pct;
  	bp = xfs_buf_read_uncached(mp->m_ddev_targp,
  				XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
  				XFS_FSS_TO_BB(mp, 1), 0, NULL);
  	if (!bp)
  		return EIO;
  	if (bp->b_error) {
  		error = bp->b_error;
  		xfs_buf_relse(bp);
  		return error;
  	}
  	xfs_buf_relse(bp);
  
  	new = nb;	/* use new as a temporary here */
  	nb_mod = do_div(new, mp->m_sb.sb_agblocks);
  	nagcount = new + (nb_mod != 0);
  	if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
  		nagcount--;
  		nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
  		if (nb < mp->m_sb.sb_dblocks)
  			return XFS_ERROR(EINVAL);
  	}
  	new = nb - mp->m_sb.sb_dblocks;
  	oagcount = mp->m_sb.sb_agcount;
  
  	/* allocate the new per-ag structures */
  	if (nagcount > oagcount) {
  		error = xfs_initialize_perag(mp, nagcount, &nagimax);
  		if (error)
  			return error;
  	}
  
  	tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFS);
  	tp->t_flags |= XFS_TRANS_RESERVE;
  	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_growdata,
  				  XFS_GROWFS_SPACE_RES(mp), 0);
  	if (error) {
  		xfs_trans_cancel(tp, 0);
  		return error;
  	}
  
  	/*
  	 * Write new AG headers to disk. Non-transactional, but written
  	 * synchronously so they are completed prior to the growfs transaction
  	 * being logged.
  	 */
  	nfree = 0;
  	for (agno = nagcount - 1; agno >= oagcount; agno--, new -= agsize) {
  		__be32	*agfl_bno;
  
  		/*
  		 * AG freespace header block
  		 */
  		bp = xfs_growfs_get_hdr_buf(mp,
  				XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
  				XFS_FSS_TO_BB(mp, 1), 0,
  				&xfs_agf_buf_ops);
  		if (!bp) {
  			error = ENOMEM;
  			goto error0;
  		}
  
  		agf = XFS_BUF_TO_AGF(bp);
  		agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
  		agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
  		agf->agf_seqno = cpu_to_be32(agno);
  		if (agno == nagcount - 1)
  			agsize =
  				nb -
  				(agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
  		else
  			agsize = mp->m_sb.sb_agblocks;
  		agf->agf_length = cpu_to_be32(agsize);
  		agf->agf_roots[XFS_BTNUM_BNOi] = cpu_to_be32(XFS_BNO_BLOCK(mp));
  		agf->agf_roots[XFS_BTNUM_CNTi] = cpu_to_be32(XFS_CNT_BLOCK(mp));
  		agf->agf_levels[XFS_BTNUM_BNOi] = cpu_to_be32(1);
  		agf->agf_levels[XFS_BTNUM_CNTi] = cpu_to_be32(1);
  		agf->agf_flfirst = 0;
  		agf->agf_fllast = cpu_to_be32(XFS_AGFL_SIZE(mp) - 1);
  		agf->agf_flcount = 0;
  		tmpsize = agsize - XFS_PREALLOC_BLOCKS(mp);
  		agf->agf_freeblks = cpu_to_be32(tmpsize);
  		agf->agf_longest = cpu_to_be32(tmpsize);
  		if (xfs_sb_version_hascrc(&mp->m_sb))
  			uuid_copy(&agf->agf_uuid, &mp->m_sb.sb_uuid);
  
  		error = xfs_bwrite(bp);
  		xfs_buf_relse(bp);
  		if (error)
  			goto error0;
  
  		/*
  		 * AG freelist header block
  		 */
  		bp = xfs_growfs_get_hdr_buf(mp,
  				XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
  				XFS_FSS_TO_BB(mp, 1), 0,
  				&xfs_agfl_buf_ops);
  		if (!bp) {
  			error = ENOMEM;
  			goto error0;
  		}
  
  		agfl = XFS_BUF_TO_AGFL(bp);
  		if (xfs_sb_version_hascrc(&mp->m_sb)) {
  			agfl->agfl_magicnum = cpu_to_be32(XFS_AGFL_MAGIC);
  			agfl->agfl_seqno = cpu_to_be32(agno);
  			uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_uuid);
  		}
  
  		agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, bp);
  		for (bucket = 0; bucket < XFS_AGFL_SIZE(mp); bucket++)
  			agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK);
  
  		error = xfs_bwrite(bp);
  		xfs_buf_relse(bp);
  		if (error)
  			goto error0;
  
  		/*
  		 * AG inode header block
  		 */
  		bp = xfs_growfs_get_hdr_buf(mp,
  				XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
  				XFS_FSS_TO_BB(mp, 1), 0,
  				&xfs_agi_buf_ops);
  		if (!bp) {
  			error = ENOMEM;
  			goto error0;
  		}
  
  		agi = XFS_BUF_TO_AGI(bp);
  		agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
  		agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
  		agi->agi_seqno = cpu_to_be32(agno);
  		agi->agi_length = cpu_to_be32(agsize);
  		agi->agi_count = 0;
  		agi->agi_root = cpu_to_be32(XFS_IBT_BLOCK(mp));
  		agi->agi_level = cpu_to_be32(1);
  		agi->agi_freecount = 0;
  		agi->agi_newino = cpu_to_be32(NULLAGINO);
  		agi->agi_dirino = cpu_to_be32(NULLAGINO);
  		if (xfs_sb_version_hascrc(&mp->m_sb))
  			uuid_copy(&agi->agi_uuid, &mp->m_sb.sb_uuid);
  		for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++)
  			agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);
  
  		error = xfs_bwrite(bp);
  		xfs_buf_relse(bp);
  		if (error)
  			goto error0;
  
  		/*
  		 * BNO btree root block
  		 */
  		bp = xfs_growfs_get_hdr_buf(mp,
  				XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
  				BTOBB(mp->m_sb.sb_blocksize), 0,
  				&xfs_allocbt_buf_ops);
  
  		if (!bp) {
  			error = ENOMEM;
  			goto error0;
  		}
  
  		if (xfs_sb_version_hascrc(&mp->m_sb))
  			xfs_btree_init_block(mp, bp, XFS_ABTB_CRC_MAGIC, 0, 1,
  						agno, XFS_BTREE_CRC_BLOCKS);
  		else
  			xfs_btree_init_block(mp, bp, XFS_ABTB_MAGIC, 0, 1,
  						agno, 0);
  
  		arec = XFS_ALLOC_REC_ADDR(mp, XFS_BUF_TO_BLOCK(bp), 1);
  		arec->ar_startblock = cpu_to_be32(XFS_PREALLOC_BLOCKS(mp));
  		arec->ar_blockcount = cpu_to_be32(
  			agsize - be32_to_cpu(arec->ar_startblock));
  
  		error = xfs_bwrite(bp);
  		xfs_buf_relse(bp);
  		if (error)
  			goto error0;
  
  		/*
  		 * CNT btree root block
  		 */
  		bp = xfs_growfs_get_hdr_buf(mp,
  				XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
  				BTOBB(mp->m_sb.sb_blocksize), 0,
  				&xfs_allocbt_buf_ops);
  		if (!bp) {
  			error = ENOMEM;
  			goto error0;
  		}
  
  		if (xfs_sb_version_hascrc(&mp->m_sb))
  			xfs_btree_init_block(mp, bp, XFS_ABTC_CRC_MAGIC, 0, 1,
  						agno, XFS_BTREE_CRC_BLOCKS);
  		else
  			xfs_btree_init_block(mp, bp, XFS_ABTC_MAGIC, 0, 1,
  						agno, 0);
  
  		arec = XFS_ALLOC_REC_ADDR(mp, XFS_BUF_TO_BLOCK(bp), 1);
  		arec->ar_startblock = cpu_to_be32(XFS_PREALLOC_BLOCKS(mp));
  		arec->ar_blockcount = cpu_to_be32(
  			agsize - be32_to_cpu(arec->ar_startblock));
  		nfree += be32_to_cpu(arec->ar_blockcount);
  
  		error = xfs_bwrite(bp);
  		xfs_buf_relse(bp);
  		if (error)
  			goto error0;
  
  		/*
  		 * INO btree root block
  		 */
  		bp = xfs_growfs_get_hdr_buf(mp,
  				XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
  				BTOBB(mp->m_sb.sb_blocksize), 0,
  				&xfs_inobt_buf_ops);
  		if (!bp) {
  			error = ENOMEM;
  			goto error0;
  		}
  
  		if (xfs_sb_version_hascrc(&mp->m_sb))
  			xfs_btree_init_block(mp, bp, XFS_IBT_CRC_MAGIC, 0, 0,
  						agno, XFS_BTREE_CRC_BLOCKS);
  		else
  			xfs_btree_init_block(mp, bp, XFS_IBT_MAGIC, 0, 0,
  						agno, 0);
  
  		error = xfs_bwrite(bp);
  		xfs_buf_relse(bp);
  		if (error)
  			goto error0;
  	}
  	xfs_trans_agblocks_delta(tp, nfree);
  	/*
  	 * There are new blocks in the old last a.g.
  	 */
  	if (new) {
  		/*
  		 * Change the agi length.
  		 */
  		error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
  		if (error) {
  			goto error0;
  		}
  		ASSERT(bp);
  		agi = XFS_BUF_TO_AGI(bp);
  		be32_add_cpu(&agi->agi_length, new);
  		ASSERT(nagcount == oagcount ||
  		       be32_to_cpu(agi->agi_length) == mp->m_sb.sb_agblocks);
  		xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
  		/*
  		 * Change agf length.
  		 */
  		error = xfs_alloc_read_agf(mp, tp, agno, 0, &bp);
  		if (error) {
  			goto error0;
  		}
  		ASSERT(bp);
  		agf = XFS_BUF_TO_AGF(bp);
  		be32_add_cpu(&agf->agf_length, new);
  		ASSERT(be32_to_cpu(agf->agf_length) ==
  		       be32_to_cpu(agi->agi_length));
  
  		xfs_alloc_log_agf(tp, bp, XFS_AGF_LENGTH);
  		/*
  		 * Free the new space.
  		 */
  		error = xfs_free_extent(tp, XFS_AGB_TO_FSB(mp, agno,
  			be32_to_cpu(agf->agf_length) - new), new);
  		if (error) {
  			goto error0;
  		}
  	}
  
  	/*
  	 * Update changed superblock fields transactionally. These are not
  	 * seen by the rest of the world until the transaction commit applies
  	 * them atomically to the superblock.
  	 */
  	if (nagcount > oagcount)
  		xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
  	if (nb > mp->m_sb.sb_dblocks)
  		xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
  				 nb - mp->m_sb.sb_dblocks);
  	if (nfree)
  		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, nfree);
  	if (dpct)
  		xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
  	error = xfs_trans_commit(tp, 0);
  	if (error)
  		return error;
  
  	/* New allocation groups fully initialized, so update mount struct */
  	if (nagimax)
  		mp->m_maxagi = nagimax;
  	if (mp->m_sb.sb_imax_pct) {
  		__uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
  		do_div(icount, 100);
  		mp->m_maxicount = icount << mp->m_sb.sb_inopblog;
  	} else
  		mp->m_maxicount = 0;
  	xfs_set_low_space_thresholds(mp);
  
  	/* update secondary superblocks. */
  	for (agno = 1; agno < nagcount; agno++) {
  		error = 0;
  		/*
  		 * new secondary superblocks need to be zeroed, not read from
  		 * disk as the contents of the new area we are growing into is
  		 * completely unknown.
  		 */
  		if (agno < oagcount) {
  			error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
  				  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
  				  XFS_FSS_TO_BB(mp, 1), 0, &bp,
  				  &xfs_sb_buf_ops);
  		} else {
  			bp = xfs_trans_get_buf(NULL, mp->m_ddev_targp,
  				  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
  				  XFS_FSS_TO_BB(mp, 1), 0);
  			if (bp) {
  				bp->b_ops = &xfs_sb_buf_ops;
  				xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
  			} else
  				error = ENOMEM;
  		}
  
  		/*
  		 * If we get an error reading or writing alternate superblocks,
  		 * continue.  xfs_repair chooses the "best" superblock based
  		 * on most matches; if we break early, we'll leave more
  		 * superblocks un-updated than updated, and xfs_repair may
  		 * pick them over the properly-updated primary.
  		 */
  		if (error) {
  			xfs_warn(mp,
  		"error %d reading secondary superblock for ag %d",
  				error, agno);
  			saved_error = error;
  			continue;
  		}
  		xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, XFS_SB_ALL_BITS);
  
  		error = xfs_bwrite(bp);
  		xfs_buf_relse(bp);
  		if (error) {
  			xfs_warn(mp,
  		"write error %d updating secondary superblock for ag %d",
  				error, agno);
  			saved_error = error;
  			continue;
  		}
  	}
  	return saved_error ? saved_error : error;
  
   error0:
  	xfs_trans_cancel(tp, XFS_TRANS_ABORT);
  	return error;
  }
  
  static int
  xfs_growfs_log_private(
  	xfs_mount_t		*mp,	/* mount point for filesystem */
  	xfs_growfs_log_t	*in)	/* growfs log input struct */
  {
  	xfs_extlen_t		nb;
  
  	nb = in->newblocks;
  	if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
  		return XFS_ERROR(EINVAL);
  	if (nb == mp->m_sb.sb_logblocks &&
  	    in->isint == (mp->m_sb.sb_logstart != 0))
  		return XFS_ERROR(EINVAL);
  	/*
  	 * Moving the log is hard, need new interfaces to sync
  	 * the log first, hold off all activity while moving it.
  	 * Can have shorter or longer log in the same space,
  	 * or transform internal to external log or vice versa.
  	 */
  	return XFS_ERROR(ENOSYS);
  }
  
  /*
   * protected versions of growfs function acquire and release locks on the mount
   * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
   * XFS_IOC_FSGROWFSRT
   */
  
  
  int
  xfs_growfs_data(
  	xfs_mount_t		*mp,
  	xfs_growfs_data_t	*in)
  {
  	int error;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return XFS_ERROR(EPERM);
  	if (!mutex_trylock(&mp->m_growlock))
  		return XFS_ERROR(EWOULDBLOCK);
  	error = xfs_growfs_data_private(mp, in);
  	mutex_unlock(&mp->m_growlock);
  	return error;
  }
  
  int
  xfs_growfs_log(
  	xfs_mount_t		*mp,
  	xfs_growfs_log_t	*in)
  {
  	int error;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return XFS_ERROR(EPERM);
  	if (!mutex_trylock(&mp->m_growlock))
  		return XFS_ERROR(EWOULDBLOCK);
  	error = xfs_growfs_log_private(mp, in);
  	mutex_unlock(&mp->m_growlock);
  	return error;
  }
  
  /*
   * exported through ioctl XFS_IOC_FSCOUNTS
   */
  
  int
  xfs_fs_counts(
  	xfs_mount_t		*mp,
  	xfs_fsop_counts_t	*cnt)
  {
  	xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT);
  	spin_lock(&mp->m_sb_lock);
  	cnt->freedata = mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
  	cnt->freertx = mp->m_sb.sb_frextents;
  	cnt->freeino = mp->m_sb.sb_ifree;
  	cnt->allocino = mp->m_sb.sb_icount;
  	spin_unlock(&mp->m_sb_lock);
  	return 0;
  }
  
  /*
   * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
   *
   * xfs_reserve_blocks is called to set m_resblks
   * in the in-core mount table. The number of unused reserved blocks
   * is kept in m_resblks_avail.
   *
   * Reserve the requested number of blocks if available. Otherwise return
   * as many as possible to satisfy the request. The actual number
   * reserved are returned in outval
   *
   * A null inval pointer indicates that only the current reserved blocks
   * available  should  be returned no settings are changed.
   */
  
  int
  xfs_reserve_blocks(
  	xfs_mount_t             *mp,
  	__uint64_t              *inval,
  	xfs_fsop_resblks_t      *outval)
  {
  	__int64_t		lcounter, delta, fdblks_delta;
  	__uint64_t		request;
  
  	/* If inval is null, report current values and return */
  	if (inval == (__uint64_t *)NULL) {
  		if (!outval)
  			return EINVAL;
  		outval->resblks = mp->m_resblks;
  		outval->resblks_avail = mp->m_resblks_avail;
  		return 0;
  	}
  
  	request = *inval;
  
  	/*
  	 * With per-cpu counters, this becomes an interesting
  	 * problem. we needto work out if we are freeing or allocation
  	 * blocks first, then we can do the modification as necessary.
  	 *
  	 * We do this under the m_sb_lock so that if we are near
  	 * ENOSPC, we will hold out any changes while we work out
  	 * what to do. This means that the amount of free space can
  	 * change while we do this, so we need to retry if we end up
  	 * trying to reserve more space than is available.
  	 *
  	 * We also use the xfs_mod_incore_sb() interface so that we
  	 * don't have to care about whether per cpu counter are
  	 * enabled, disabled or even compiled in....
  	 */
  retry:
  	spin_lock(&mp->m_sb_lock);
  	xfs_icsb_sync_counters_locked(mp, 0);
  
  	/*
  	 * If our previous reservation was larger than the current value,
  	 * then move any unused blocks back to the free pool.
  	 */
  	fdblks_delta = 0;
  	if (mp->m_resblks > request) {
  		lcounter = mp->m_resblks_avail - request;
  		if (lcounter  > 0) {		/* release unused blocks */
  			fdblks_delta = lcounter;
  			mp->m_resblks_avail -= lcounter;
  		}
  		mp->m_resblks = request;
  	} else {
  		__int64_t	free;
  
  		free =  mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
  		if (!free)
  			goto out; /* ENOSPC and fdblks_delta = 0 */
  
  		delta = request - mp->m_resblks;
  		lcounter = free - delta;
  		if (lcounter < 0) {
  			/* We can't satisfy the request, just get what we can */
  			mp->m_resblks += free;
  			mp->m_resblks_avail += free;
  			fdblks_delta = -free;
  		} else {
  			fdblks_delta = -delta;
  			mp->m_resblks = request;
  			mp->m_resblks_avail += delta;
  		}
  	}
  out:
  	if (outval) {
  		outval->resblks = mp->m_resblks;
  		outval->resblks_avail = mp->m_resblks_avail;
  	}
  	spin_unlock(&mp->m_sb_lock);
  
  	if (fdblks_delta) {
  		/*
  		 * If we are putting blocks back here, m_resblks_avail is
  		 * already at its max so this will put it in the free pool.
  		 *
  		 * If we need space, we'll either succeed in getting it
  		 * from the free block count or we'll get an enospc. If
  		 * we get a ENOSPC, it means things changed while we were
  		 * calculating fdblks_delta and so we should try again to
  		 * see if there is anything left to reserve.
  		 *
  		 * Don't set the reserved flag here - we don't want to reserve
  		 * the extra reserve blocks from the reserve.....
  		 */
  		int error;
  		error = xfs_icsb_modify_counters(mp, XFS_SBS_FDBLOCKS,
  						 fdblks_delta, 0);
  		if (error == ENOSPC)
  			goto retry;
  	}
  	return 0;
  }
  
  /*
   * Dump a transaction into the log that contains no real change. This is needed
   * to be able to make the log dirty or stamp the current tail LSN into the log
   * during the covering operation.
   *
   * We cannot use an inode here for this - that will push dirty state back up
   * into the VFS and then periodic inode flushing will prevent log covering from
   * making progress. Hence we log a field in the superblock instead and use a
   * synchronous transaction to ensure the superblock is immediately unpinned
   * and can be written back.
   */
  int
  xfs_fs_log_dummy(
  	xfs_mount_t	*mp)
  {
  	xfs_trans_t	*tp;
  	int		error;
  
  	tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1, KM_SLEEP);
  	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_sb, 0, 0);
  	if (error) {
  		xfs_trans_cancel(tp, 0);
  		return error;
  	}
  
  	/* log the UUID because it is an unchanging field */
  	xfs_mod_sb(tp, XFS_SB_UUID);
  	xfs_trans_set_sync(tp);
  	return xfs_trans_commit(tp, 0);
  }
  
  int
  xfs_fs_goingdown(
  	xfs_mount_t	*mp,
  	__uint32_t	inflags)
  {
  	switch (inflags) {
  	case XFS_FSOP_GOING_FLAGS_DEFAULT: {
  		struct super_block *sb = freeze_bdev(mp->m_super->s_bdev);
  
  		if (sb && !IS_ERR(sb)) {
  			xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
  			thaw_bdev(sb->s_bdev, sb);
  		}
  
  		break;
  	}
  	case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
  		xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
  		break;
  	case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
  		xfs_force_shutdown(mp,
  				SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
  		break;
  	default:
  		return XFS_ERROR(EINVAL);
  	}
  
  	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)) {
  		xfs_notice(mp,
  	"%s(0x%x) called from line %d of file %s.  Return address = 0x%p",
  			__func__, 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_alert_tag(mp, XFS_PTAG_SHUTDOWN_CORRUPT,
      "Corruption of in-memory data detected.  Shutting down filesystem");
  		if (XFS_ERRLEVEL_HIGH <= xfs_error_level)
  			xfs_stack_trace();
  	} else if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
  		if (logerror) {
  			xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_LOGERROR,
  		"Log I/O Error Detected.  Shutting down filesystem");
  		} else if (flags & SHUTDOWN_DEVICE_REQ) {
  			xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_IOERROR,
  		"All device paths lost.  Shutting down filesystem");
  		} else if (!(flags & SHUTDOWN_REMOTE_REQ)) {
  			xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_IOERROR,
  		"I/O Error Detected. Shutting down filesystem");
  		}
  	}
  	if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
  		xfs_alert(mp,
  	"Please umount the filesystem and rectify the problem(s)");
  	}
  }