Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 695 insertions, 0 deletions

diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
new file mode 100644
index 00000000..1c6fdeb7
--- /dev/null
+++ b/fs/xfs/xfs_fsops.c
@@ -0,0 +1,695 @@
+/*
+ * 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_types.h"
+#include "xfs_bit.h"
+#include "xfs_inum.h"
+#include "xfs_log.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_mount.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_inode_item.h"
+#include "xfs_btree.h"
+#include "xfs_error.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_rw.h"
+#include "xfs_filestream.h"
+#include "xfs_trace.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);
+		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 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;
+	xfs_agi_t		*agi;
+	xfs_agnumber_t		agno;
+	xfs_extlen_t		agsize;
+	xfs_extlen_t		tmpsize;
+	xfs_alloc_rec_t		*arec;
+	struct xfs_btree_block	*block;
+	xfs_buf_t		*bp;
+	int			bucket;
+	int			dpct;
+	int			error;
+	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, mp->m_ddev_targp,
+				XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
+				BBTOB(XFS_FSS_TO_BB(mp, 1)), 0);
+	if (!bp)
+		return EIO;
+	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;
+	if ((error = xfs_trans_reserve(tp, XFS_GROWFS_SPACE_RES(mp),
+			XFS_GROWDATA_LOG_RES(mp), 0, 0, 0))) {
+		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) {
+		/*
+		 * AG freelist header block
+		 */
+		bp = xfs_buf_get(mp->m_ddev_targp,
+				 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
+				 XFS_FSS_TO_BB(mp, 1), XBF_LOCK | XBF_MAPPED);
+		if (!bp) {
+			error = ENOMEM;
+			goto error0;
+		}
+		agf = XFS_BUF_TO_AGF(bp);
+		memset(agf, 0, mp->m_sb.sb_sectsize);
+		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);
+		error = xfs_bwrite(bp);
+		xfs_buf_relse(bp);
+		if (error)
+			goto error0;
+
+		/*
+		 * AG inode header block
+		 */
+		bp = xfs_buf_get(mp->m_ddev_targp,
+				 XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
+				 XFS_FSS_TO_BB(mp, 1), XBF_LOCK | XBF_MAPPED);
+		if (!bp) {
+			error = ENOMEM;
+			goto error0;
+		}
+		agi = XFS_BUF_TO_AGI(bp);
+		memset(agi, 0, mp->m_sb.sb_sectsize);
+		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);
+		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_buf_get(mp->m_ddev_targp,
+				 XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
+				 BTOBB(mp->m_sb.sb_blocksize),
+				 XBF_LOCK | XBF_MAPPED);
+		if (!bp) {
+			error = ENOMEM;
+			goto error0;
+		}
+		block = XFS_BUF_TO_BLOCK(bp);
+		memset(block, 0, mp->m_sb.sb_blocksize);
+		block->bb_magic = cpu_to_be32(XFS_ABTB_MAGIC);
+		block->bb_level = 0;
+		block->bb_numrecs = cpu_to_be16(1);
+		block->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
+		block->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
+		arec = XFS_ALLOC_REC_ADDR(mp, block, 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_buf_get(mp->m_ddev_targp,
+				 XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
+				 BTOBB(mp->m_sb.sb_blocksize),
+				 XBF_LOCK | XBF_MAPPED);
+		if (!bp) {
+			error = ENOMEM;
+			goto error0;
+		}
+		block = XFS_BUF_TO_BLOCK(bp);
+		memset(block, 0, mp->m_sb.sb_blocksize);
+		block->bb_magic = cpu_to_be32(XFS_ABTC_MAGIC);
+		block->bb_level = 0;
+		block->bb_numrecs = cpu_to_be16(1);
+		block->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
+		block->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
+		arec = XFS_ALLOC_REC_ADDR(mp, block, 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_buf_get(mp->m_ddev_targp,
+				 XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
+				 BTOBB(mp->m_sb.sb_blocksize),
+				 XBF_LOCK | XBF_MAPPED);
+		if (!bp) {
+			error = ENOMEM;
+			goto error0;
+		}
+		block = XFS_BUF_TO_BLOCK(bp);
+		memset(block, 0, mp->m_sb.sb_blocksize);
+		block->bb_magic = cpu_to_be32(XFS_IBT_MAGIC);
+		block->bb_level = 0;
+		block->bb_numrecs = 0;
+		block->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
+		block->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
+		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 = xfs_read_buf(mp, mp->m_ddev_targp,
+				  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
+				  XFS_FSS_TO_BB(mp, 1), 0, &bp);
+		if (error) {
+			xfs_warn(mp,
+		"error %d reading secondary superblock for ag %d",
+				error, agno);
+			break;
+		}
+		xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, XFS_SB_ALL_BITS);
+		/*
+		 * If we get an error writing out the alternate superblocks,
+		 * just issue a warning and continue.  The real work is
+		 * already done and committed.
+		 */
+		error = xfs_bwrite(bp);
+		xfs_buf_relse(bp);
+		if (error) {
+			xfs_warn(mp,
+		"write error %d updating secondary superblock for ag %d",
+				error, agno);
+			break; /* no point in continuing */
+		}
+	}
+	return 0;
+
+ 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, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
+					XFS_DEFAULT_LOG_COUNT);
+	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;
+}