text: // SPDX-License-Identifier: GPL-2.0
  /*
   * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   * All Rights Reserved.
   */
  #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_bit.h"
  #include "xfs_sb.h"
  #include "xfs_mount.h"
  #include "xfs_inode.h"
  #include "xfs_dir2.h"
  #include "xfs_ialloc.h"
  #include "xfs_alloc.h"
  #include "xfs_rtalloc.h"
  #include "xfs_bmap.h"
  #include "xfs_trans.h"
  #include "xfs_trans_priv.h"
  #include "xfs_log.h"
  #include "xfs_error.h"
  #include "xfs_quota.h"
  #include "xfs_fsops.h"
  #include "xfs_icache.h"
  #include "xfs_sysfs.h"
  #include "xfs_rmap_btree.h"
  #include "xfs_refcount_btree.h"
  #include "xfs_reflink.h"
  #include "xfs_extent_busy.h"
  #include "xfs_health.h"
  #include "xfs_trace.h"
  #include "xfs_ag.h"
  
  static DEFINE_MUTEX(xfs_uuid_table_mutex);
  static int xfs_uuid_table_size;
  static uuid_t *xfs_uuid_table;
  
  void
  xfs_uuid_table_free(void)
  {
  	if (xfs_uuid_table_size == 0)
  		return;
  	kmem_free(xfs_uuid_table);
  	xfs_uuid_table = NULL;
  	xfs_uuid_table_size = 0;
  }
  
  /*
   * See if the UUID is unique among mounted XFS filesystems.
   * Mount fails if UUID is nil or a FS with the same UUID is already mounted.
   */
  STATIC int
  xfs_uuid_mount(
  	struct xfs_mount	*mp)
  {
  	uuid_t			*uuid = &mp->m_sb.sb_uuid;
  	int			hole, i;
  
  	/* Publish UUID in struct super_block */
  	uuid_copy(&mp->m_super->s_uuid, uuid);
  
  	if (xfs_has_nouuid(mp))
  		return 0;
  
  	if (uuid_is_null(uuid)) {
  		xfs_warn(mp, "Filesystem has null UUID - can't mount");
  		return -EINVAL;
  	}
  
  	mutex_lock(&xfs_uuid_table_mutex);
  	for (i = 0, hole = -1; i < xfs_uuid_table_size; i++) {
  		if (uuid_is_null(&xfs_uuid_table[i])) {
  			hole = i;
  			continue;
  		}
  		if (uuid_equal(uuid, &xfs_uuid_table[i]))
  			goto out_duplicate;
  	}
  
  	if (hole < 0) {
  		xfs_uuid_table = krealloc(xfs_uuid_table,
  			(xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
  			GFP_KERNEL | __GFP_NOFAIL);
  		hole = xfs_uuid_table_size++;
  	}
  	xfs_uuid_table[hole] = *uuid;
  	mutex_unlock(&xfs_uuid_table_mutex);
  
  	return 0;
  
   out_duplicate:
  	mutex_unlock(&xfs_uuid_table_mutex);
  	xfs_warn(mp, "Filesystem has duplicate UUID %pU - can't mount", uuid);
  	return -EINVAL;
  }
  
  STATIC void
  xfs_uuid_unmount(
  	struct xfs_mount	*mp)
  {
  	uuid_t			*uuid = &mp->m_sb.sb_uuid;
  	int			i;
  
  	if (xfs_has_nouuid(mp))
  		return;
  
  	mutex_lock(&xfs_uuid_table_mutex);
  	for (i = 0; i < xfs_uuid_table_size; i++) {
  		if (uuid_is_null(&xfs_uuid_table[i]))
  			continue;
  		if (!uuid_equal(uuid, &xfs_uuid_table[i]))
  			continue;
  		memset(&xfs_uuid_table[i], 0, sizeof(uuid_t));
  		break;
  	}
  	ASSERT(i < xfs_uuid_table_size);
  	mutex_unlock(&xfs_uuid_table_mutex);
  }
  
  /*
   * Check size of device based on the (data/realtime) block count.
   * Note: this check is used by the growfs code as well as mount.
   */
  int
  xfs_sb_validate_fsb_count(
  	xfs_sb_t	*sbp,
  	uint64_t	nblocks)
  {
  	ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
  	ASSERT(sbp->sb_blocklog >= BBSHIFT);
  
  	/* Limited by ULONG_MAX of page cache index */
  	if (nblocks >> (PAGE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
  		return -EFBIG;
  	return 0;
  }
  
  /*
   * xfs_readsb
   *
   * Does the initial read of the superblock.
   */
  int
  xfs_readsb(
  	struct xfs_mount *mp,
  	int		flags)
  {
  	unsigned int	sector_size;
  	struct xfs_buf	*bp;
  	struct xfs_sb	*sbp = &mp->m_sb;
  	int		error;
  	int		loud = !(flags & XFS_MFSI_QUIET);
  	const struct xfs_buf_ops *buf_ops;
  
  	ASSERT(mp->m_sb_bp == NULL);
  	ASSERT(mp->m_ddev_targp != NULL);
  
  	/*
  	 * For the initial read, we must guess at the sector
  	 * size based on the block device.  It's enough to
  	 * get the sb_sectsize out of the superblock and
  	 * then reread with the proper length.
  	 * We don't verify it yet, because it may not be complete.
  	 */
  	sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
  	buf_ops = NULL;
  
  	/*
  	 * Allocate a (locked) buffer to hold the superblock. This will be kept
  	 * around at all times to optimize access to the superblock. Therefore,
  	 * set XBF_NO_IOACCT to make sure it doesn't hold the buftarg count
  	 * elevated.
  	 */
  reread:
  	error = xfs_buf_read_uncached(mp->m_ddev_targp, XFS_SB_DADDR,
  				      BTOBB(sector_size), XBF_NO_IOACCT, &bp,
  				      buf_ops);
  	if (error) {
  		if (loud)
  			xfs_warn(mp, "SB validate failed with error %d.", error);
  		/* bad CRC means corrupted metadata */
  		if (error == -EFSBADCRC)
  			error = -EFSCORRUPTED;
  		return error;
  	}
  
  	/*
  	 * Initialize the mount structure from the superblock.
  	 */
  	xfs_sb_from_disk(sbp, bp->b_addr);
  
  	/*
  	 * If we haven't validated the superblock, do so now before we try
  	 * to check the sector size and reread the superblock appropriately.
  	 */
  	if (sbp->sb_magicnum != XFS_SB_MAGIC) {
  		if (loud)
  			xfs_warn(mp, "Invalid superblock magic number");
  		error = -EINVAL;
  		goto release_buf;
  	}
  
  	/*
  	 * We must be able to do sector-sized and sector-aligned IO.
  	 */
  	if (sector_size > sbp->sb_sectsize) {
  		if (loud)
  			xfs_warn(mp, "device supports %u byte sectors (not %u)",
  				sector_size, sbp->sb_sectsize);
  		error = -ENOSYS;
  		goto release_buf;
  	}
  
  	if (buf_ops == NULL) {
  		/*
  		 * Re-read the superblock so the buffer is correctly sized,
  		 * and properly verified.
  		 */
  		xfs_buf_relse(bp);
  		sector_size = sbp->sb_sectsize;
  		buf_ops = loud ? &xfs_sb_buf_ops : &xfs_sb_quiet_buf_ops;
  		goto reread;
  	}
  
  	mp->m_features |= xfs_sb_version_to_features(sbp);
  	xfs_reinit_percpu_counters(mp);
  
  	/* no need to be quiet anymore, so reset the buf ops */
  	bp->b_ops = &xfs_sb_buf_ops;
  
  	mp->m_sb_bp = bp;
  	xfs_buf_unlock(bp);
  	return 0;
  
  release_buf:
  	xfs_buf_relse(bp);
  	return error;
  }
  
  /*
   * If the sunit/swidth change would move the precomputed root inode value, we
   * must reject the ondisk change because repair will stumble over that.
   * However, we allow the mount to proceed because we never rejected this
   * combination before.  Returns true to update the sb, false otherwise.
   */
  static inline int
  xfs_check_new_dalign(
  	struct xfs_mount	*mp,
  	int			new_dalign,
  	bool			*update_sb)
  {
  	struct xfs_sb		*sbp = &mp->m_sb;
  	xfs_ino_t		calc_ino;
  
  	calc_ino = xfs_ialloc_calc_rootino(mp, new_dalign);
  	trace_xfs_check_new_dalign(mp, new_dalign, calc_ino);
  
  	if (sbp->sb_rootino == calc_ino) {
  		*update_sb = true;
  		return 0;
  	}
  
  	xfs_warn(mp,
  "Cannot change stripe alignment; would require moving root inode.");
  
  	/*
  	 * XXX: Next time we add a new incompat feature, this should start
  	 * returning -EINVAL to fail the mount.  Until then, spit out a warning
  	 * that we're ignoring the administrator's instructions.
  	 */
  	xfs_warn(mp, "Skipping superblock stripe alignment update.");
  	*update_sb = false;
  	return 0;
  }
  
  /*
   * If we were provided with new sunit/swidth values as mount options, make sure
   * that they pass basic alignment and superblock feature checks, and convert
   * them into the same units (FSB) that everything else expects.  This step
   * /must/ be done before computing the inode geometry.
   */
  STATIC int
  xfs_validate_new_dalign(
  	struct xfs_mount	*mp)
  {
  	if (mp->m_dalign == 0)
  		return 0;
  
  	/*
  	 * If stripe unit and stripe width are not multiples
  	 * of the fs blocksize turn off alignment.
  	 */
  	if ((BBTOB(mp->m_dalign) & mp->m_blockmask) ||
  	    (BBTOB(mp->m_swidth) & mp->m_blockmask)) {
  		xfs_warn(mp,
  	"alignment check failed: sunit/swidth vs. blocksize(%d)",
  			mp->m_sb.sb_blocksize);
  		return -EINVAL;
  	} else {
  		/*
  		 * Convert the stripe unit and width to FSBs.
  		 */
  		mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign);
  		if (mp->m_dalign && (mp->m_sb.sb_agblocks % mp->m_dalign)) {
  			xfs_warn(mp,
  		"alignment check failed: sunit/swidth vs. agsize(%d)",
  				 mp->m_sb.sb_agblocks);
  			return -EINVAL;
  		} else if (mp->m_dalign) {
  			mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
  		} else {
  			xfs_warn(mp,
  		"alignment check failed: sunit(%d) less than bsize(%d)",
  				 mp->m_dalign, mp->m_sb.sb_blocksize);
  			return -EINVAL;
  		}
  	}
  
  	if (!xfs_has_dalign(mp)) {
  		xfs_warn(mp,
  "cannot change alignment: superblock does not support data alignment");
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  /* Update alignment values based on mount options and sb values. */
  STATIC int
  xfs_update_alignment(
  	struct xfs_mount	*mp)
  {
  	struct xfs_sb		*sbp = &mp->m_sb;
  
  	if (mp->m_dalign) {
  		bool		update_sb;
  		int		error;
  
  		if (sbp->sb_unit == mp->m_dalign &&
  		    sbp->sb_width == mp->m_swidth)
  			return 0;
  
  		error = xfs_check_new_dalign(mp, mp->m_dalign, &update_sb);
  		if (error || !update_sb)
  			return error;
  
  		sbp->sb_unit = mp->m_dalign;
  		sbp->sb_width = mp->m_swidth;
  		mp->m_update_sb = true;
  	} else if (!xfs_has_noalign(mp) && xfs_has_dalign(mp)) {
  		mp->m_dalign = sbp->sb_unit;
  		mp->m_swidth = sbp->sb_width;
  	}
  
  	return 0;
  }
  
  /*
   * precalculate the low space thresholds for dynamic speculative preallocation.
   */
  void
  xfs_set_low_space_thresholds(
  	struct xfs_mount	*mp)
  {
  	uint64_t		dblocks = mp->m_sb.sb_dblocks;
  	uint64_t		rtexts = mp->m_sb.sb_rextents;
  	int			i;
  
  	do_div(dblocks, 100);
  	do_div(rtexts, 100);
  
  	for (i = 0; i < XFS_LOWSP_MAX; i++) {
  		mp->m_low_space[i] = dblocks * (i + 1);
  		mp->m_low_rtexts[i] = rtexts * (i + 1);
  	}
  }
  
  /*
   * Check that the data (and log if separate) is an ok size.
   */
  STATIC int
  xfs_check_sizes(
  	struct xfs_mount *mp)
  {
  	struct xfs_buf	*bp;
  	xfs_daddr_t	d;
  	int		error;
  
  	d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
  	if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
  		xfs_warn(mp, "filesystem size mismatch detected");
  		return -EFBIG;
  	}
  	error = xfs_buf_read_uncached(mp->m_ddev_targp,
  					d - XFS_FSS_TO_BB(mp, 1),
  					XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL);
  	if (error) {
  		xfs_warn(mp, "last sector read failed");
  		return error;
  	}
  	xfs_buf_relse(bp);
  
  	if (mp->m_logdev_targp == mp->m_ddev_targp)
  		return 0;
  
  	d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
  	if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
  		xfs_warn(mp, "log size mismatch detected");
  		return -EFBIG;
  	}
  	error = xfs_buf_read_uncached(mp->m_logdev_targp,
  					d - XFS_FSB_TO_BB(mp, 1),
  					XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
  	if (error) {
  		xfs_warn(mp, "log device read failed");
  		return error;
  	}
  	xfs_buf_relse(bp);
  	return 0;
  }
  
  /*
   * Clear the quotaflags in memory and in the superblock.
   */
  int
  xfs_mount_reset_sbqflags(
  	struct xfs_mount	*mp)
  {
  	mp->m_qflags = 0;
  
  	/* It is OK to look at sb_qflags in the mount path without m_sb_lock. */
  	if (mp->m_sb.sb_qflags == 0)
  		return 0;
  	spin_lock(&mp->m_sb_lock);
  	mp->m_sb.sb_qflags = 0;
  	spin_unlock(&mp->m_sb_lock);
  
  	if (!xfs_fs_writable(mp, SB_FREEZE_WRITE))
  		return 0;
  
  	return xfs_sync_sb(mp, false);
  }
  
  uint64_t
  xfs_default_resblks(xfs_mount_t *mp)
  {
  	uint64_t resblks;
  
  	/*
  	 * We default to 5% or 8192 fsbs of space reserved, whichever is
  	 * smaller.  This is intended to cover concurrent allocation
  	 * transactions when we initially hit enospc. These each require a 4
  	 * block reservation. Hence by default we cover roughly 2000 concurrent
  	 * allocation reservations.
  	 */
  	resblks = mp->m_sb.sb_dblocks;
  	do_div(resblks, 20);
  	resblks = min_t(uint64_t, resblks, 8192);
  	return resblks;
  }
  
  /* Ensure the summary counts are correct. */
  STATIC int
  xfs_check_summary_counts(
  	struct xfs_mount	*mp)
  {
  	/*
  	 * The AG0 superblock verifier rejects in-progress filesystems,
  	 * so we should never see the flag set this far into mounting.
  	 */
  	if (mp->m_sb.sb_inprogress) {
  		xfs_err(mp, "sb_inprogress set after log recovery??");
  		WARN_ON(1);
  		return -EFSCORRUPTED;
  	}
  
  	/*
  	 * Now the log is mounted, we know if it was an unclean shutdown or
  	 * not. If it was, with the first phase of recovery has completed, we
  	 * have consistent AG blocks on disk. We have not recovered EFIs yet,
  	 * but they are recovered transactionally in the second recovery phase
  	 * later.
  	 *
  	 * If the log was clean when we mounted, we can check the summary
  	 * counters.  If any of them are obviously incorrect, we can recompute
  	 * them from the AGF headers in the next step.
  	 */
  	if (xfs_is_clean(mp) &&
  	    (mp->m_sb.sb_fdblocks > mp->m_sb.sb_dblocks ||
  	     !xfs_verify_icount(mp, mp->m_sb.sb_icount) ||
  	     mp->m_sb.sb_ifree > mp->m_sb.sb_icount))
  		xfs_fs_mark_sick(mp, XFS_SICK_FS_COUNTERS);
  
  	/*
  	 * We can safely re-initialise incore superblock counters from the
  	 * per-ag data. These may not be correct if the filesystem was not
  	 * cleanly unmounted, so we waited for recovery to finish before doing
  	 * this.
  	 *
  	 * If the filesystem was cleanly unmounted or the previous check did
  	 * not flag anything weird, then we can trust the values in the
  	 * superblock to be correct and we don't need to do anything here.
  	 * Otherwise, recalculate the summary counters.
  	 */
  	if ((!xfs_has_lazysbcount(mp) || xfs_is_clean(mp)) &&
  	    !xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS))
  		return 0;
  
  	return xfs_initialize_perag_data(mp, mp->m_sb.sb_agcount);
  }
  
  /*
   * Flush and reclaim dirty inodes in preparation for unmount. Inodes and
   * internal inode structures can be sitting in the CIL and AIL at this point,
   * so we need to unpin them, write them back and/or reclaim them before unmount
   * can proceed.  In other words, callers are required to have inactivated all
   * inodes.
   *
   * An inode cluster that has been freed can have its buffer still pinned in
   * memory because the transaction is still sitting in a iclog. The stale inodes
   * on that buffer will be pinned to the buffer until the transaction hits the
   * disk and the callbacks run. Pushing the AIL will skip the stale inodes and
   * may never see the pinned buffer, so nothing will push out the iclog and
   * unpin the buffer.
   *
   * Hence we need to force the log to unpin everything first. However, log
   * forces don't wait for the discards they issue to complete, so we have to
   * explicitly wait for them to complete here as well.
   *
   * Then we can tell the world we are unmounting so that error handling knows
   * that the filesystem is going away and we should error out anything that we
   * have been retrying in the background.  This will prevent never-ending
   * retries in AIL pushing from hanging the unmount.
   *
   * Finally, we can push the AIL to clean all the remaining dirty objects, then
   * reclaim the remaining inodes that are still in memory at this point in time.
   */
  static void
  xfs_unmount_flush_inodes(
  	struct xfs_mount	*mp)
  {
  	xfs_log_force(mp, XFS_LOG_SYNC);
  	xfs_extent_busy_wait_all(mp);
  	flush_workqueue(xfs_discard_wq);
  
  	set_bit(XFS_OPSTATE_UNMOUNTING, &mp->m_opstate);
  
  	xfs_ail_push_all_sync(mp->m_ail);
  	xfs_inodegc_stop(mp);
  	cancel_delayed_work_sync(&mp->m_reclaim_work);
  	xfs_reclaim_inodes(mp);
  	xfs_health_unmount(mp);
  }
  
  static void
  xfs_mount_setup_inode_geom(
  	struct xfs_mount	*mp)
  {
  	struct xfs_ino_geometry *igeo = M_IGEO(mp);
  
  	igeo->attr_fork_offset = xfs_bmap_compute_attr_offset(mp);
  	ASSERT(igeo->attr_fork_offset < XFS_LITINO(mp));
  
  	xfs_ialloc_setup_geometry(mp);
  }
  
  /* Compute maximum possible height for per-AG btree types for this fs. */
  static inline void
  xfs_agbtree_compute_maxlevels(
  	struct xfs_mount	*mp)
  {
  	unsigned int		levels;
  
  	levels = max(mp->m_alloc_maxlevels, M_IGEO(mp)->inobt_maxlevels);
  	levels = max(levels, mp->m_rmap_maxlevels);
  	mp->m_agbtree_maxlevels = max(levels, mp->m_refc_maxlevels);
  }
  
  /*
   * This function does the following on an initial mount of a file system:
   *	- reads the superblock from disk and init the mount struct
   *	- if we're a 32-bit kernel, do a size check on the superblock
   *		so we don't mount terabyte filesystems
   *	- init mount struct realtime fields
   *	- allocate inode hash table for fs
   *	- init directory manager
   *	- perform recovery and init the log manager
   */
  int
  xfs_mountfs(
  	struct xfs_mount	*mp)
  {
  	struct xfs_sb		*sbp = &(mp->m_sb);
  	struct xfs_inode	*rip;
  	struct xfs_ino_geometry	*igeo = M_IGEO(mp);
  	uint64_t		resblks;
  	uint			quotamount = 0;
  	uint			quotaflags = 0;
  	int			error = 0;
  
  	xfs_sb_mount_common(mp, sbp);
  
  	/*
  	 * Check for a mismatched features2 values.  Older kernels read & wrote
  	 * into the wrong sb offset for sb_features2 on some platforms due to
  	 * xfs_sb_t not being 64bit size aligned when sb_features2 was added,
  	 * which made older superblock reading/writing routines swap it as a
  	 * 64-bit value.
  	 *
  	 * For backwards compatibility, we make both slots equal.
  	 *
  	 * If we detect a mismatched field, we OR the set bits into the existing
  	 * features2 field in case it has already been modified; we don't want
  	 * to lose any features.  We then update the bad location with the ORed
  	 * value so that older kernels will see any features2 flags. The
  	 * superblock writeback code ensures the new sb_features2 is copied to
  	 * sb_bad_features2 before it is logged or written to disk.
  	 */
  	if (xfs_sb_has_mismatched_features2(sbp)) {
  		xfs_warn(mp, "correcting sb_features alignment problem");
  		sbp->sb_features2 |= sbp->sb_bad_features2;
  		mp->m_update_sb = true;
  	}
  
  
  	/* always use v2 inodes by default now */
  	if (!(mp->m_sb.sb_versionnum & XFS_SB_VERSION_NLINKBIT)) {
  		mp->m_sb.sb_versionnum |= XFS_SB_VERSION_NLINKBIT;
  		mp->m_features |= XFS_FEAT_NLINK;
  		mp->m_update_sb = true;
  	}
  
  	/*
  	 * If we were given new sunit/swidth options, do some basic validation
  	 * checks and convert the incore dalign and swidth values to the
  	 * same units (FSB) that everything else uses.  This /must/ happen
  	 * before computing the inode geometry.
  	 */
  	error = xfs_validate_new_dalign(mp);
  	if (error)
  		goto out;
  
  	xfs_alloc_compute_maxlevels(mp);
  	xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
  	xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);
  	xfs_mount_setup_inode_geom(mp);
  	xfs_rmapbt_compute_maxlevels(mp);
  	xfs_refcountbt_compute_maxlevels(mp);
  
  	xfs_agbtree_compute_maxlevels(mp);
  
  	/*
  	 * Check if sb_agblocks is aligned at stripe boundary.  If sb_agblocks
  	 * is NOT aligned turn off m_dalign since allocator alignment is within
  	 * an ag, therefore ag has to be aligned at stripe boundary.  Note that
  	 * we must compute the free space and rmap btree geometry before doing
  	 * this.
  	 */
  	error = xfs_update_alignment(mp);
  	if (error)
  		goto out;
  
  	/* enable fail_at_unmount as default */
  	mp->m_fail_unmount = true;
  
  	error = xfs_sysfs_init(&mp->m_kobj, &xfs_mp_ktype,
  			       NULL, mp->m_super->s_id);
  	if (error)
  		goto out;
  
  	error = xfs_sysfs_init(&mp->m_stats.xs_kobj, &xfs_stats_ktype,
  			       &mp->m_kobj, "stats");
  	if (error)
  		goto out_remove_sysfs;
  
  	error = xfs_error_sysfs_init(mp);
  	if (error)
  		goto out_del_stats;
  
  	error = xfs_errortag_init(mp);
  	if (error)
  		goto out_remove_error_sysfs;
  
  	error = xfs_uuid_mount(mp);
  	if (error)
  		goto out_remove_errortag;
  
  	/*
  	 * Update the preferred write size based on the information from the
  	 * on-disk superblock.
  	 */
  	mp->m_allocsize_log =
  		max_t(uint32_t, sbp->sb_blocklog, mp->m_allocsize_log);
  	mp->m_allocsize_blocks = 1U << (mp->m_allocsize_log - sbp->sb_blocklog);
  
  	/* set the low space thresholds for dynamic preallocation */
  	xfs_set_low_space_thresholds(mp);
  
  	/*
  	 * If enabled, sparse inode chunk alignment is expected to match the
  	 * cluster size. Full inode chunk alignment must match the chunk size,
  	 * but that is checked on sb read verification...
  	 */
  	if (xfs_has_sparseinodes(mp) &&
  	    mp->m_sb.sb_spino_align !=
  			XFS_B_TO_FSBT(mp, igeo->inode_cluster_size_raw)) {
  		xfs_warn(mp,
  	"Sparse inode block alignment (%u) must match cluster size (%llu).",
  			 mp->m_sb.sb_spino_align,
  			 XFS_B_TO_FSBT(mp, igeo->inode_cluster_size_raw));
  		error = -EINVAL;
  		goto out_remove_uuid;
  	}
  
  	/*
  	 * Check that the data (and log if separate) is an ok size.
  	 */
  	error = xfs_check_sizes(mp);
  	if (error)
  		goto out_remove_uuid;
  
  	/*
  	 * Initialize realtime fields in the mount structure
  	 */
  	error = xfs_rtmount_init(mp);
  	if (error) {
  		xfs_warn(mp, "RT mount failed");
  		goto out_remove_uuid;
  	}
  
  	/*
  	 *  Copies the low order bits of the timestamp and the randomly
  	 *  set "sequence" number out of a UUID.
  	 */
  	mp->m_fixedfsid[0] =
  		(get_unaligned_be16(&sbp->sb_uuid.b[8]) << 16) |
  		 get_unaligned_be16(&sbp->sb_uuid.b[4]);
  	mp->m_fixedfsid[1] = get_unaligned_be32(&sbp->sb_uuid.b[0]);
  
  	error = xfs_da_mount(mp);
  	if (error) {
  		xfs_warn(mp, "Failed dir/attr init: %d", error);
  		goto out_remove_uuid;
  	}
  
  	/*
  	 * Initialize the precomputed transaction reservations values.
  	 */
  	xfs_trans_init(mp);
  
  	/*
  	 * Allocate and initialize the per-ag data.
  	 */
  	error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
  	if (error) {
  		xfs_warn(mp, "Failed per-ag init: %d", error);
  		goto out_free_dir;
  	}
  
  	if (XFS_IS_CORRUPT(mp, !sbp->sb_logblocks)) {
  		xfs_warn(mp, "no log defined");
  		error = -EFSCORRUPTED;
  		goto out_free_perag;
  	}
  
  	error = xfs_inodegc_register_shrinker(mp);
  	if (error)
  		goto out_fail_wait;
  
  	/*
  	 * Log's mount-time initialization. The first part of recovery can place
  	 * some items on the AIL, to be handled when recovery is finished or
  	 * cancelled.
  	 */
  	error = xfs_log_mount(mp, mp->m_logdev_targp,
  			      XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
  			      XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
  	if (error) {
  		xfs_warn(mp, "log mount failed");
  		goto out_inodegc_shrinker;
  	}
  
  	/* Make sure the summary counts are ok. */
  	error = xfs_check_summary_counts(mp);
  	if (error)
  		goto out_log_dealloc;
  
  	/* Enable background inode inactivation workers. */
  	xfs_inodegc_start(mp);
  	xfs_blockgc_start(mp);
  
  	/*
  	 * Now that we've recovered any pending superblock feature bit
  	 * additions, we can finish setting up the attr2 behaviour for the
  	 * mount. The noattr2 option overrides the superblock flag, so only
  	 * check the superblock feature flag if the mount option is not set.
  	 */
  	if (xfs_has_noattr2(mp)) {
  		mp->m_features &= ~XFS_FEAT_ATTR2;
  	} else if (!xfs_has_attr2(mp) &&
  		   (mp->m_sb.sb_features2 & XFS_SB_VERSION2_ATTR2BIT)) {
  		mp->m_features |= XFS_FEAT_ATTR2;
  	}
  
  	/*
  	 * Get and sanity-check the root inode.
  	 * Save the pointer to it in the mount structure.
  	 */
  	error = xfs_iget(mp, NULL, sbp->sb_rootino, XFS_IGET_UNTRUSTED,
  			 XFS_ILOCK_EXCL, &rip);
  	if (error) {
  		xfs_warn(mp,
  			"Failed to read root inode 0x%llx, error %d",
  			sbp->sb_rootino, -error);
  		goto out_log_dealloc;
  	}
  
  	ASSERT(rip != NULL);
  
  	if (XFS_IS_CORRUPT(mp, !S_ISDIR(VFS_I(rip)->i_mode))) {
  		xfs_warn(mp, "corrupted root inode %llu: not a directory",
  			(unsigned long long)rip->i_ino);
  		xfs_iunlock(rip, XFS_ILOCK_EXCL);
  		error = -EFSCORRUPTED;
  		goto out_rele_rip;
  	}
  	mp->m_rootip = rip;	/* save it */
  
  	xfs_iunlock(rip, XFS_ILOCK_EXCL);
  
  	/*
  	 * Initialize realtime inode pointers in the mount structure
  	 */
  	error = xfs_rtmount_inodes(mp);
  	if (error) {
  		/*
  		 * Free up the root inode.
  		 */
  		xfs_warn(mp, "failed to read RT inodes");
  		goto out_rele_rip;
  	}
  
  	/*
  	 * If this is a read-only mount defer the superblock updates until
  	 * the next remount into writeable mode.  Otherwise we would never
  	 * perform the update e.g. for the root filesystem.
  	 */
  	if (mp->m_update_sb && !xfs_is_readonly(mp)) {
  		error = xfs_sync_sb(mp, false);
  		if (error) {
  			xfs_warn(mp, "failed to write sb changes");
  			goto out_rtunmount;
  		}
  	}
  
  	/*
  	 * Initialise the XFS quota management subsystem for this mount
  	 */
  	if (XFS_IS_QUOTA_ON(mp)) {
  		error = xfs_qm_newmount(mp, &quotamount, &quotaflags);
  		if (error)
  			goto out_rtunmount;
  	} else {
  		/*
  		 * If a file system had quotas running earlier, but decided to
  		 * mount without -o uquota/pquota/gquota options, revoke the
  		 * quotachecked license.
  		 */
  		if (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT) {
  			xfs_notice(mp, "resetting quota flags");
  			error = xfs_mount_reset_sbqflags(mp);
  			if (error)
  				goto out_rtunmount;
  		}
  	}
  
  	/*
  	 * Finish recovering the file system.  This part needed to be delayed
  	 * until after the root and real-time bitmap inodes were consistently
  	 * read in.  Temporarily create per-AG space reservations for metadata
  	 * btree shape changes because space freeing transactions (for inode
  	 * inactivation) require the per-AG reservation in lieu of reserving
  	 * blocks.
  	 */
  	error = xfs_fs_reserve_ag_blocks(mp);
  	if (error && error == -ENOSPC)
  		xfs_warn(mp,
  	"ENOSPC reserving per-AG metadata pool, log recovery may fail.");
  	error = xfs_log_mount_finish(mp);
  	xfs_fs_unreserve_ag_blocks(mp);
  	if (error) {
  		xfs_warn(mp, "log mount finish failed");
  		goto out_rtunmount;
  	}
  
  	/*
  	 * Now the log is fully replayed, we can transition to full read-only
  	 * mode for read-only mounts. This will sync all the metadata and clean
  	 * the log so that the recovery we just performed does not have to be
  	 * replayed again on the next mount.
  	 *
  	 * We use the same quiesce mechanism as the rw->ro remount, as they are
  	 * semantically identical operations.
  	 */
  	if (xfs_is_readonly(mp) && !xfs_has_norecovery(mp))
  		xfs_log_clean(mp);
  
  	/*
  	 * Complete the quota initialisation, post-log-replay component.
  	 */
  	if (quotamount) {
  		ASSERT(mp->m_qflags == 0);
  		mp->m_qflags = quotaflags;
  
  		xfs_qm_mount_quotas(mp);
  	}
  
  	/*
  	 * Now we are mounted, reserve a small amount of unused space for
  	 * privileged transactions. This is needed so that transaction
  	 * space required for critical operations can dip into this pool
  	 * when at ENOSPC. This is needed for operations like create with
  	 * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
  	 * are not allowed to use this reserved space.
  	 *
  	 * This may drive us straight to ENOSPC on mount, but that implies
  	 * we were already there on the last unmount. Warn if this occurs.
  	 */
  	if (!xfs_is_readonly(mp)) {
  		resblks = xfs_default_resblks(mp);
  		error = xfs_reserve_blocks(mp, &resblks, NULL);
  		if (error)
  			xfs_warn(mp,
  	"Unable to allocate reserve blocks. Continuing without reserve pool.");
  
  		/* Recover any CoW blocks that never got remapped. */
  		error = xfs_reflink_recover_cow(mp);
  		if (error) {
  			xfs_err(mp,
  	"Error %d recovering leftover CoW allocations.", error);
  			xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
  			goto out_quota;
  		}
  
  		/* Reserve AG blocks for future btree expansion. */
  		error = xfs_fs_reserve_ag_blocks(mp);
  		if (error && error != -ENOSPC)
  			goto out_agresv;
  	}
  
  	return 0;
  
   out_agresv:
  	xfs_fs_unreserve_ag_blocks(mp);
   out_quota:
  	xfs_qm_unmount_quotas(mp);
   out_rtunmount:
  	xfs_rtunmount_inodes(mp);
   out_rele_rip:
  	xfs_irele(rip);
  	/* Clean out dquots that might be in memory after quotacheck. */
  	xfs_qm_unmount(mp);
  
  	/*
  	 * Inactivate all inodes that might still be in memory after a log
  	 * intent recovery failure so that reclaim can free them.  Metadata
  	 * inodes and the root directory shouldn't need inactivation, but the
  	 * mount failed for some reason, so pull down all the state and flee.
  	 */
  	xfs_inodegc_flush(mp);
  
  	/*
  	 * Flush all inode reclamation work and flush the log.
  	 * We have to do this /after/ rtunmount and qm_unmount because those
  	 * two will have scheduled delayed reclaim for the rt/quota inodes.
  	 *
  	 * This is slightly different from the unmountfs call sequence
  	 * because we could be tearing down a partially set up mount.  In
  	 * particular, if log_mount_finish fails we bail out without calling
  	 * qm_unmount_quotas and therefore rely on qm_unmount to release the
  	 * quota inodes.
  	 */
  	xfs_unmount_flush_inodes(mp);
   out_log_dealloc:
  	xfs_log_mount_cancel(mp);
   out_inodegc_shrinker:
  	unregister_shrinker(&mp->m_inodegc_shrinker);
   out_fail_wait:
  	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
  		xfs_buftarg_drain(mp->m_logdev_targp);
  	xfs_buftarg_drain(mp->m_ddev_targp);
   out_free_perag:
  	xfs_free_perag(mp);
   out_free_dir:
  	xfs_da_unmount(mp);
   out_remove_uuid:
  	xfs_uuid_unmount(mp);
   out_remove_errortag:
  	xfs_errortag_del(mp);
   out_remove_error_sysfs:
  	xfs_error_sysfs_del(mp);
   out_del_stats:
  	xfs_sysfs_del(&mp->m_stats.xs_kobj);
   out_remove_sysfs:
  	xfs_sysfs_del(&mp->m_kobj);
   out:
  	return error;
  }
  
  /*
   * This flushes out the inodes,dquots and the superblock, unmounts the
   * log and makes sure that incore structures are freed.
   */
  void
  xfs_unmountfs(
  	struct xfs_mount	*mp)
  {
  	uint64_t		resblks;
  	int			error;
  
  	/*
  	 * Perform all on-disk metadata updates required to inactivate inodes
  	 * that the VFS evicted earlier in the unmount process.  Freeing inodes
  	 * and discarding CoW fork preallocations can cause shape changes to
  	 * the free inode and refcount btrees, respectively, so we must finish
  	 * this before we discard the metadata space reservations.  Metadata
  	 * inodes and the root directory do not require inactivation.
  	 */
  	xfs_inodegc_flush(mp);
  
  	xfs_blockgc_stop(mp);
  	xfs_fs_unreserve_ag_blocks(mp);
  	xfs_qm_unmount_quotas(mp);
  	xfs_rtunmount_inodes(mp);
  	xfs_irele(mp->m_rootip);
  
  	xfs_unmount_flush_inodes(mp);
  
  	xfs_qm_unmount(mp);
  
  	/*
  	 * Unreserve any blocks we have so that when we unmount we don't account
  	 * the reserved free space as used. This is really only necessary for
  	 * lazy superblock counting because it trusts the incore superblock
  	 * counters to be absolutely correct on clean unmount.
  	 *
  	 * We don't bother correcting this elsewhere for lazy superblock
  	 * counting because on mount of an unclean filesystem we reconstruct the
  	 * correct counter value and this is irrelevant.
  	 *
  	 * For non-lazy counter filesystems, this doesn't matter at all because
  	 * we only every apply deltas to the superblock and hence the incore
  	 * value does not matter....
  	 */
  	resblks = 0;
  	error = xfs_reserve_blocks(mp, &resblks, NULL);
  	if (error)
  		xfs_warn(mp, "Unable to free reserved block pool. "
  				"Freespace may not be correct on next mount.");
  
  	xfs_log_unmount(mp);
  	xfs_da_unmount(mp);
  	xfs_uuid_unmount(mp);
  
  #if defined(DEBUG)
  	xfs_errortag_clearall(mp);
  #endif
  	unregister_shrinker(&mp->m_inodegc_shrinker);
  	xfs_free_perag(mp);
  
  	xfs_errortag_del(mp);
  	xfs_error_sysfs_del(mp);
  	xfs_sysfs_del(&mp->m_stats.xs_kobj);
  	xfs_sysfs_del(&mp->m_kobj);
  }
  
  /*
   * Determine whether modifications can proceed. The caller specifies the minimum
   * freeze level for which modifications should not be allowed. This allows
   * certain operations to proceed while the freeze sequence is in progress, if
   * necessary.
   */
  bool
  xfs_fs_writable(
  	struct xfs_mount	*mp,
  	int			level)
  {
  	ASSERT(level > SB_UNFROZEN);
  	if ((mp->m_super->s_writers.frozen >= level) ||
  	    xfs_is_shutdown(mp) || xfs_is_readonly(mp))
  		return false;
  
  	return true;
  }
  
  int
  xfs_mod_fdblocks(
  	struct xfs_mount	*mp,
  	int64_t			delta,
  	bool			rsvd)
  {
  	int64_t			lcounter;
  	long long		res_used;
  	s32			batch;
  	uint64_t		set_aside;
  
  	if (delta > 0) {
  		/*
  		 * If the reserve pool is depleted, put blocks back into it
  		 * first. Most of the time the pool is full.
  		 */
  		if (likely(mp->m_resblks == mp->m_resblks_avail)) {
  			percpu_counter_add(&mp->m_fdblocks, delta);
  			return 0;
  		}
  
  		spin_lock(&mp->m_sb_lock);
  		res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
  
  		if (res_used > delta) {
  			mp->m_resblks_avail += delta;
  		} else {
  			delta -= res_used;
  			mp->m_resblks_avail = mp->m_resblks;
  			percpu_counter_add(&mp->m_fdblocks, delta);
  		}
  		spin_unlock(&mp->m_sb_lock);
  		return 0;
  	}
  
  	/*
  	 * Taking blocks away, need to be more accurate the closer we
  	 * are to zero.
  	 *
  	 * If the counter has a value of less than 2 * max batch size,
  	 * then make everything serialise as we are real close to
  	 * ENOSPC.
  	 */
  	if (__percpu_counter_compare(&mp->m_fdblocks, 2 * XFS_FDBLOCKS_BATCH,
  				     XFS_FDBLOCKS_BATCH) < 0)
  		batch = 1;
  	else
  		batch = XFS_FDBLOCKS_BATCH;
  
  	/*
  	 * Set aside allocbt blocks because these blocks are tracked as free
  	 * space but not available for allocation. Technically this means that a
  	 * single reservation cannot consume all remaining free space, but the
  	 * ratio of allocbt blocks to usable free blocks should be rather small.
  	 * The tradeoff without this is that filesystems that maintain high
  	 * perag block reservations can over reserve physical block availability
  	 * and fail physical allocation, which leads to much more serious
  	 * problems (i.e. transaction abort, pagecache discards, etc.) than
  	 * slightly premature -ENOSPC.
  	 */
  	set_aside = mp->m_alloc_set_aside + atomic64_read(&mp->m_allocbt_blks);
  	percpu_counter_add_batch(&mp->m_fdblocks, delta, batch);
  	if (__percpu_counter_compare(&mp->m_fdblocks, set_aside,
  				     XFS_FDBLOCKS_BATCH) >= 0) {
  		/* we had space! */
  		return 0;
  	}
  
  	/*
  	 * lock up the sb for dipping into reserves before releasing the space
  	 * that took us to ENOSPC.
  	 */
  	spin_lock(&mp->m_sb_lock);
  	percpu_counter_add(&mp->m_fdblocks, -delta);
  	if (!rsvd)
  		goto fdblocks_enospc;
  
  	lcounter = (long long)mp->m_resblks_avail + delta;
  	if (lcounter >= 0) {
  		mp->m_resblks_avail = lcounter;
  		spin_unlock(&mp->m_sb_lock);
  		return 0;
  	}
  	xfs_warn_once(mp,
  "Reserve blocks depleted! Consider increasing reserve pool size.");
  
  fdblocks_enospc:
  	spin_unlock(&mp->m_sb_lock);
  	return -ENOSPC;
  }
  
  int
  xfs_mod_frextents(
  	struct xfs_mount	*mp,
  	int64_t			delta)
  {
  	int64_t			lcounter;
  	int			ret = 0;
  
  	spin_lock(&mp->m_sb_lock);
  	lcounter = mp->m_sb.sb_frextents + delta;
  	if (lcounter < 0)
  		ret = -ENOSPC;
  	else
  		mp->m_sb.sb_frextents = lcounter;
  	spin_unlock(&mp->m_sb_lock);
  	return ret;
  }
  
  /*
   * Used to free the superblock along various error paths.
   */
  void
  xfs_freesb(
  	struct xfs_mount	*mp)
  {
  	struct xfs_buf		*bp = mp->m_sb_bp;
  
  	xfs_buf_lock(bp);
  	mp->m_sb_bp = NULL;
  	xfs_buf_relse(bp);
  }
  
  /*
   * If the underlying (data/log/rt) device is readonly, there are some
   * operations that cannot proceed.
   */
  int
  xfs_dev_is_read_only(
  	struct xfs_mount	*mp,
  	char			*message)
  {
  	if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
  	    xfs_readonly_buftarg(mp->m_logdev_targp) ||
  	    (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
  		xfs_notice(mp, "%s required on read-only device.", message);
  		xfs_notice(mp, "write access unavailable, cannot proceed.");
  		return -EROFS;
  	}
  	return 0;
  }
  
  /* Force the summary counters to be recalculated at next mount. */
  void
  xfs_force_summary_recalc(
  	struct xfs_mount	*mp)
  {
  	if (!xfs_has_lazysbcount(mp))
  		return;
  
  	xfs_fs_mark_sick(mp, XFS_SICK_FS_COUNTERS);
  }
  
  /*
   * Enable a log incompat feature flag in the primary superblock.  The caller
   * cannot have any other transactions in progress.
   */
  int
  xfs_add_incompat_log_feature(
  	struct xfs_mount	*mp,
  	uint32_t		feature)
  {
  	struct xfs_dsb		*dsb;
  	int			error;
  
  	ASSERT(hweight32(feature) == 1);
  	ASSERT(!(feature & XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN));
  
  	/*
  	 * Force the log to disk and kick the background AIL thread to reduce
  	 * the chances that the bwrite will stall waiting for the AIL to unpin
  	 * the primary superblock buffer.  This isn't a data integrity
  	 * operation, so we don't need a synchronous push.
  	 */
  	error = xfs_log_force(mp, XFS_LOG_SYNC);
  	if (error)
  		return error;
  	xfs_ail_push_all(mp->m_ail);
  
  	/*
  	 * Lock the primary superblock buffer to serialize all callers that
  	 * are trying to set feature bits.
  	 */
  	xfs_buf_lock(mp->m_sb_bp);
  	xfs_buf_hold(mp->m_sb_bp);
  
  	if (xfs_is_shutdown(mp)) {
  		error = -EIO;
  		goto rele;
  	}
  
  	if (xfs_sb_has_incompat_log_feature(&mp->m_sb, feature))
  		goto rele;
  
  	/*
  	 * Write the primary superblock to disk immediately, because we need
  	 * the log_incompat bit to be set in the primary super now to protect
  	 * the log items that we're going to commit later.
  	 */
  	dsb = mp->m_sb_bp->b_addr;
  	xfs_sb_to_disk(dsb, &mp->m_sb);
  	dsb->sb_features_log_incompat |= cpu_to_be32(feature);
  	error = xfs_bwrite(mp->m_sb_bp);
  	if (error)
  		goto shutdown;
  
  	/*
  	 * Add the feature bits to the incore superblock before we unlock the
  	 * buffer.
  	 */
  	xfs_sb_add_incompat_log_features(&mp->m_sb, feature);
  	xfs_buf_relse(mp->m_sb_bp);
  
  	/* Log the superblock to disk. */
  	return xfs_sync_sb(mp, false);
  shutdown:
  	xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
  rele:
  	xfs_buf_relse(mp->m_sb_bp);
  	return error;
  }
  
  /*
   * Clear all the log incompat flags from the superblock.
   *
   * The caller cannot be in a transaction, must ensure that the log does not
   * contain any log items protected by any log incompat bit, and must ensure
   * that there are no other threads that depend on the state of the log incompat
   * feature flags in the primary super.
   *
   * Returns true if the superblock is dirty.
   */
  bool
  xfs_clear_incompat_log_features(
  	struct xfs_mount	*mp)
  {
  	bool			ret = false;
  
  	if (!xfs_has_crc(mp) ||
  	    !xfs_sb_has_incompat_log_feature(&mp->m_sb,
  				XFS_SB_FEAT_INCOMPAT_LOG_ALL) ||
  	    xfs_is_shutdown(mp))
  		return false;
  
  	/*
  	 * Update the incore superblock.  We synchronize on the primary super
  	 * buffer lock to be consistent with the add function, though at least
  	 * in theory this shouldn't be necessary.
  	 */
  	xfs_buf_lock(mp->m_sb_bp);
  	xfs_buf_hold(mp->m_sb_bp);
  
  	if (xfs_sb_has_incompat_log_feature(&mp->m_sb,
  				XFS_SB_FEAT_INCOMPAT_LOG_ALL)) {
  		xfs_info(mp, "Clearing log incompat feature flags.");
  		xfs_sb_remove_incompat_log_features(&mp->m_sb);
  		ret = true;
  	}
  
  	xfs_buf_relse(mp->m_sb_bp);
  	return ret;
  }
  
  /*
   * Update the in-core delayed block counter.
   *
   * We prefer to update the counter without having to take a spinlock for every
   * counter update (i.e. batching).  Each change to delayed allocation
   * reservations can change can easily exceed the default percpu counter
   * batching, so we use a larger batch factor here.
   *
   * Note that we don't currently have any callers requiring fast summation
   * (e.g. percpu_counter_read) so we can use a big batch value here.
   */
  #define XFS_DELALLOC_BATCH	(4096)
  void
  xfs_mod_delalloc(
  	struct xfs_mount	*mp,
  	int64_t			delta)
  {
  	percpu_counter_add_batch(&mp->m_delalloc_blks, delta,
  			XFS_DELALLOC_BATCH);
  }
  