fs/xfs/xfs_fsops.c - kernel/msm-5.4 - Gitiles

 // 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_sb.h"
 #include "xfs_mount.h"
 #include "xfs_trans.h"
 #include "xfs_error.h"
 #include "xfs_alloc.h"
 #include "xfs_fsops.h"
 #include "xfs_trans_space.h"
 #include "xfs_log.h"
 #include "xfs_ag.h"
 #include "xfs_ag_resv.h"

 /*
  * growfs operations
  */
 static int
 xfs_growfs_data_private(
 	xfs_mount_t		*mp,		/* mount point for filesystem */
 	xfs_growfs_data_t	*in)		/* growfs data input struct */
 {
 	xfs_buf_t		*bp;
 	int			error;
 	xfs_agnumber_t		nagcount;
 	xfs_agnumber_t		nagimax = 0;
 	xfs_rfsblock_t		nb, nb_mod;
 	xfs_rfsblock_t		new;
 	xfs_agnumber_t		oagcount;
 	xfs_trans_t		*tp;
 	struct aghdr_init_data	id = {};

 	nb = in->newblocks;
 	if (nb < mp->m_sb.sb_dblocks)
 		return -EINVAL;
 	if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
 		return error;
 	error = 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, &bp, NULL);
 	if (error)
 		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 -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;
 	}

 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
 			XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
 	if (error)
 		return error;

 	/*
 	 * Write new AG headers to disk. Non-transactional, but need to be
 	 * written and completed prior to the growfs transaction being logged.
 	 * To do this, we use a delayed write buffer list and wait for
 	 * submission and IO completion of the list as a whole. This allows the
 	 * IO subsystem to merge all the AG headers in a single AG into a single
 	 * IO and hide most of the latency of the IO from us.
 	 *
 	 * This also means that if we get an error whilst building the buffer
 	 * list to write, we can cancel the entire list without having written
 	 * anything.
 	 */
 	INIT_LIST_HEAD(&id.buffer_list);
 	for (id.agno = nagcount - 1;
 	     id.agno >= oagcount;
 	     id.agno--, new -= id.agsize) {

 		if (id.agno == nagcount - 1)
 			id.agsize = nb -
 				(id.agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
 		else
 			id.agsize = mp->m_sb.sb_agblocks;

 		error = xfs_ag_init_headers(mp, &id);
 		if (error) {
 			xfs_buf_delwri_cancel(&id.buffer_list);
 			goto out_trans_cancel;
 		}
 	}
 	error = xfs_buf_delwri_submit(&id.buffer_list);
 	if (error)
 		goto out_trans_cancel;

 	xfs_trans_agblocks_delta(tp, id.nfree);

 	/* If there are new blocks in the old last AG, extend it. */
 	if (new) {
 		error = xfs_ag_extend_space(mp, tp, &id, new);
 		if (error)
 			goto out_trans_cancel;
 	}

 	/*
 	 * 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 (id.nfree)
 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree);
 	xfs_trans_set_sync(tp);
 	error = xfs_trans_commit(tp);
 	if (error)
 		return error;

 	/* New allocation groups fully initialized, so update mount struct */
 	if (nagimax)
 		mp->m_maxagi = nagimax;
 	xfs_set_low_space_thresholds(mp);
 	mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);

 	/*
 	 * If we expanded the last AG, free the per-AG reservation
 	 * so we can reinitialize it with the new size.
 	 */
 	if (new) {
 		struct xfs_perag	*pag;

 		pag = xfs_perag_get(mp, id.agno);
 		error = xfs_ag_resv_free(pag);
 		xfs_perag_put(pag);
 		if (error)
 			return error;
 	}

 	/*
 	 * Reserve AG metadata blocks. ENOSPC here does not mean there was a
 	 * growfs failure, just that there still isn't space for new user data
 	 * after the grow has been run.
 	 */
 	error = xfs_fs_reserve_ag_blocks(mp);
 	if (error == -ENOSPC)
 		error = 0;
 	return error;

 out_trans_cancel:
 	xfs_trans_cancel(tp);
 	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 -EINVAL;
 	if (nb == mp->m_sb.sb_logblocks &&
 	    in->isint == (mp->m_sb.sb_logstart != 0))
 		return -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 -ENOSYS;
 }

 static int
 xfs_growfs_imaxpct(
 	struct xfs_mount	*mp,
 	__u32			imaxpct)
 {
 	struct xfs_trans	*tp;
 	int			dpct;
 	int			error;

 	if (imaxpct > 100)
 		return -EINVAL;

 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
 			XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
 	if (error)
 		return error;

 	dpct = imaxpct - mp->m_sb.sb_imax_pct;
 	xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
 	xfs_trans_set_sync(tp);
 	return xfs_trans_commit(tp);
 }

 /*
  * 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(
 	struct xfs_mount	*mp,
 	struct xfs_growfs_data	*in)
 {
 	int			error = 0;

 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 	if (!mutex_trylock(&mp->m_growlock))
 		return -EWOULDBLOCK;

 	/* update imaxpct separately to the physical grow of the filesystem */
 	if (in->imaxpct != mp->m_sb.sb_imax_pct) {
 		error = xfs_growfs_imaxpct(mp, in->imaxpct);
 		if (error)
 			goto out_error;
 	}

 	if (in->newblocks != mp->m_sb.sb_dblocks) {
 		error = xfs_growfs_data_private(mp, in);
 		if (error)
 			goto out_error;
 	}

 	/* Post growfs calculations needed to reflect new state in operations */
 	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);
 		M_IGEO(mp)->maxicount = XFS_FSB_TO_INO(mp, icount);
 	} else
 		M_IGEO(mp)->maxicount = 0;

 	/* Update secondary superblocks now the physical grow has completed */
 	error = xfs_update_secondary_sbs(mp);

 out_error:
 	/*
 	 * Increment the generation unconditionally, the error could be from
 	 * updating the secondary superblocks, in which case the new size
 	 * is live already.
 	 */
 	mp->m_generation++;
 	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 -EPERM;
 	if (!mutex_trylock(&mp->m_growlock))
 		return -EWOULDBLOCK;
 	error = xfs_growfs_log_private(mp, in);
 	mutex_unlock(&mp->m_growlock);
 	return error;
 }

 /*
  * exported through ioctl XFS_IOC_FSCOUNTS
  */

 void
 xfs_fs_counts(
 	xfs_mount_t		*mp,
 	xfs_fsop_counts_t	*cnt)
 {
 	cnt->allocino = percpu_counter_read_positive(&mp->m_icount);
 	cnt->freeino = percpu_counter_read_positive(&mp->m_ifree);
 	cnt->freedata = percpu_counter_read_positive(&mp->m_fdblocks) -
 						mp->m_alloc_set_aside;

 	spin_lock(&mp->m_sb_lock);
 	cnt->freertx = mp->m_sb.sb_frextents;
 	spin_unlock(&mp->m_sb_lock);
 }

 /*
  * 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;
 	int64_t			fdblks_delta = 0;
 	uint64_t		request;
 	int64_t			free;
 	int			error = 0;

 	/* 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 need
 	 * to 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.
 	 */
 	spin_lock(&mp->m_sb_lock);

 	/*
 	 * If our previous reservation was larger than the current value,
 	 * then move any unused blocks back to the free pool. Modify the resblks
 	 * counters directly since we shouldn't have any problems unreserving
 	 * space.
 	 */
 	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;
 		if (fdblks_delta) {
 			spin_unlock(&mp->m_sb_lock);
 			error = xfs_mod_fdblocks(mp, fdblks_delta, 0);
 			spin_lock(&mp->m_sb_lock);
 		}

 		goto out;
 	}

 	/*
 	 * If the request is larger than the current reservation, reserve the
 	 * blocks before we update the reserve counters. Sample m_fdblocks and
 	 * perform a partial reservation if the request exceeds free space.
 	 */
 	error = -ENOSPC;
 	do {
 		free = percpu_counter_sum(&mp->m_fdblocks) -
 						mp->m_alloc_set_aside;
 		if (free <= 0)
 			break;

 		delta = request - mp->m_resblks;
 		lcounter = free - delta;
 		if (lcounter < 0)
 			/* We can't satisfy the request, just get what we can */
 			fdblks_delta = free;
 		else
 			fdblks_delta = delta;

 		/*
 		 * We'll either succeed in getting space 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.....
 		 */
 		spin_unlock(&mp->m_sb_lock);
 		error = xfs_mod_fdblocks(mp, -fdblks_delta, 0);
 		spin_lock(&mp->m_sb_lock);
 	} while (error == -ENOSPC);

 	/*
 	 * Update the reserve counters if blocks have been successfully
 	 * allocated.
 	 */
 	if (!error && fdblks_delta) {
 		mp->m_resblks += fdblks_delta;
 		mp->m_resblks_avail += fdblks_delta;
 	}

 out:
 	if (outval) {
 		outval->resblks = mp->m_resblks;
 		outval->resblks_avail = mp->m_resblks_avail;
 	}

 	spin_unlock(&mp->m_sb_lock);
 	return error;
 }

 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 -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(
 	struct xfs_mount *mp,
 	int		flags,
 	char		*fname,
 	int		lnnum)
 {
 	bool		logerror = flags & SHUTDOWN_LOG_IO_ERROR;

 	/*
 	 * 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_FORCE_UMOUNT) {
 		xfs_alert(mp,
 "User initiated shutdown received. Shutting down filesystem");
 		return;
 	}

 	xfs_notice(mp,
 "%s(0x%x) called from line %d of file %s. Return address = "PTR_FMT,
 		__func__, flags, lnnum, fname, __return_address);

 	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 (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");
 	}

 	xfs_alert(mp,
 		"Please unmount the filesystem and rectify the problem(s)");
 }

 /*
  * Reserve free space for per-AG metadata.
  */
 int
 xfs_fs_reserve_ag_blocks(
 	struct xfs_mount	*mp)
 {
 	xfs_agnumber_t		agno;
 	struct xfs_perag	*pag;
 	int			error = 0;
 	int			err2;

 	mp->m_finobt_nores = false;
 	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
 		pag = xfs_perag_get(mp, agno);
 		err2 = xfs_ag_resv_init(pag, NULL);
 		xfs_perag_put(pag);
 		if (err2 && !error)
 			error = err2;
 	}

 	if (error && error != -ENOSPC) {
 		xfs_warn(mp,
 	"Error %d reserving per-AG metadata reserve pool.", error);
 		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
 	}

 	return error;
 }

 /*
  * Free space reserved for per-AG metadata.
  */
 int
 xfs_fs_unreserve_ag_blocks(
 	struct xfs_mount	*mp)
 {
 	xfs_agnumber_t		agno;
 	struct xfs_perag	*pag;
 	int			error = 0;
 	int			err2;

 	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
 		pag = xfs_perag_get(mp, agno);
 		err2 = xfs_ag_resv_free(pag);
 		xfs_perag_put(pag);
 		if (err2 && !error)
 			error = err2;
 	}

 	if (error)
 		xfs_warn(mp,
 	"Error %d freeing per-AG metadata reserve pool.", error);

 	return error;
 }
	// 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_sb.h"
	#include "xfs_mount.h"
	#include "xfs_trans.h"
	#include "xfs_error.h"
	#include "xfs_alloc.h"
	#include "xfs_fsops.h"
	#include "xfs_trans_space.h"
	#include "xfs_log.h"
	#include "xfs_ag.h"
	#include "xfs_ag_resv.h"

	/*
	* growfs operations
	*/
	static int
	xfs_growfs_data_private(
	xfs_mount_t mp, / mount point for filesystem */
	xfs_growfs_data_t in) / growfs data input struct */
	{
	xfs_buf_t *bp;
	int error;
	xfs_agnumber_t nagcount;
	xfs_agnumber_t nagimax = 0;
	xfs_rfsblock_t nb, nb_mod;
	xfs_rfsblock_t new;
	xfs_agnumber_t oagcount;
	xfs_trans_t *tp;
	struct aghdr_init_data id = {};

	nb = in->newblocks;
	if (nb < mp->m_sb.sb_dblocks)
	return -EINVAL;
	if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
	return error;
	error = 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, &bp, NULL);
	if (error)
	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 -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;
	}

	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
	XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
	if (error)
	return error;

	/*
	* Write new AG headers to disk. Non-transactional, but need to be
	* written and completed prior to the growfs transaction being logged.
	* To do this, we use a delayed write buffer list and wait for
	* submission and IO completion of the list as a whole. This allows the
	* IO subsystem to merge all the AG headers in a single AG into a single
	* IO and hide most of the latency of the IO from us.
	*
	* This also means that if we get an error whilst building the buffer
	* list to write, we can cancel the entire list without having written
	* anything.
	*/
	INIT_LIST_HEAD(&id.buffer_list);
	for (id.agno = nagcount - 1;
	id.agno >= oagcount;
	id.agno--, new -= id.agsize) {

	if (id.agno == nagcount - 1)
	id.agsize = nb -
	(id.agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
	else
	id.agsize = mp->m_sb.sb_agblocks;

	error = xfs_ag_init_headers(mp, &id);
	if (error) {
	xfs_buf_delwri_cancel(&id.buffer_list);
	goto out_trans_cancel;
	}
	}
	error = xfs_buf_delwri_submit(&id.buffer_list);
	if (error)
	goto out_trans_cancel;

	xfs_trans_agblocks_delta(tp, id.nfree);

	/* If there are new blocks in the old last AG, extend it. */
	if (new) {
	error = xfs_ag_extend_space(mp, tp, &id, new);
	if (error)
	goto out_trans_cancel;
	}

	/*
	* 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 (id.nfree)
	xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree);
	xfs_trans_set_sync(tp);
	error = xfs_trans_commit(tp);
	if (error)
	return error;

	/* New allocation groups fully initialized, so update mount struct */
	if (nagimax)
	mp->m_maxagi = nagimax;
	xfs_set_low_space_thresholds(mp);
	mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);

	/*
	* If we expanded the last AG, free the per-AG reservation
	* so we can reinitialize it with the new size.
	*/
	if (new) {
	struct xfs_perag *pag;

	pag = xfs_perag_get(mp, id.agno);
	error = xfs_ag_resv_free(pag);
	xfs_perag_put(pag);
	if (error)
	return error;
	}

	/*
	* Reserve AG metadata blocks. ENOSPC here does not mean there was a
	* growfs failure, just that there still isn't space for new user data
	* after the grow has been run.
	*/
	error = xfs_fs_reserve_ag_blocks(mp);
	if (error == -ENOSPC)
	error = 0;
	return error;

	out_trans_cancel:
	xfs_trans_cancel(tp);
	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 -EINVAL;
	if (nb == mp->m_sb.sb_logblocks &&
	in->isint == (mp->m_sb.sb_logstart != 0))
	return -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 -ENOSYS;
	}

	static int
	xfs_growfs_imaxpct(
	struct xfs_mount *mp,
	__u32 imaxpct)
	{
	struct xfs_trans *tp;
	int dpct;
	int error;

	if (imaxpct > 100)
	return -EINVAL;

	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
	XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
	if (error)
	return error;

	dpct = imaxpct - mp->m_sb.sb_imax_pct;
	xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
	xfs_trans_set_sync(tp);
	return xfs_trans_commit(tp);
	}

	/*
	* 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(
	struct xfs_mount *mp,
	struct xfs_growfs_data *in)
	{
	int error = 0;

	if (!capable(CAP_SYS_ADMIN))
	return -EPERM;
	if (!mutex_trylock(&mp->m_growlock))
	return -EWOULDBLOCK;

	/* update imaxpct separately to the physical grow of the filesystem */
	if (in->imaxpct != mp->m_sb.sb_imax_pct) {
	error = xfs_growfs_imaxpct(mp, in->imaxpct);
	if (error)
	goto out_error;
	}

	if (in->newblocks != mp->m_sb.sb_dblocks) {
	error = xfs_growfs_data_private(mp, in);
	if (error)
	goto out_error;
	}

	/* Post growfs calculations needed to reflect new state in operations */
	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);
	M_IGEO(mp)->maxicount = XFS_FSB_TO_INO(mp, icount);
	} else
	M_IGEO(mp)->maxicount = 0;

	/* Update secondary superblocks now the physical grow has completed */
	error = xfs_update_secondary_sbs(mp);

	out_error:
	/*
	* Increment the generation unconditionally, the error could be from
	* updating the secondary superblocks, in which case the new size
	* is live already.
	*/
	mp->m_generation++;
	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 -EPERM;
	if (!mutex_trylock(&mp->m_growlock))
	return -EWOULDBLOCK;
	error = xfs_growfs_log_private(mp, in);
	mutex_unlock(&mp->m_growlock);
	return error;
	}

	/*
	* exported through ioctl XFS_IOC_FSCOUNTS
	*/

	void
	xfs_fs_counts(
	xfs_mount_t *mp,
	xfs_fsop_counts_t *cnt)
	{
	cnt->allocino = percpu_counter_read_positive(&mp->m_icount);
	cnt->freeino = percpu_counter_read_positive(&mp->m_ifree);
	cnt->freedata = percpu_counter_read_positive(&mp->m_fdblocks) -
	mp->m_alloc_set_aside;

	spin_lock(&mp->m_sb_lock);
	cnt->freertx = mp->m_sb.sb_frextents;
	spin_unlock(&mp->m_sb_lock);
	}

	/*
	* 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;
	int64_t fdblks_delta = 0;
	uint64_t request;
	int64_t free;
	int error = 0;

	/* 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 need
	* to 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.
	*/
	spin_lock(&mp->m_sb_lock);

	/*
	* If our previous reservation was larger than the current value,
	* then move any unused blocks back to the free pool. Modify the resblks
	* counters directly since we shouldn't have any problems unreserving
	* space.
	*/
	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;
	if (fdblks_delta) {
	spin_unlock(&mp->m_sb_lock);
	error = xfs_mod_fdblocks(mp, fdblks_delta, 0);
	spin_lock(&mp->m_sb_lock);
	}

	goto out;
	}

	/*
	* If the request is larger than the current reservation, reserve the
	* blocks before we update the reserve counters. Sample m_fdblocks and
	* perform a partial reservation if the request exceeds free space.
	*/
	error = -ENOSPC;
	do {
	free = percpu_counter_sum(&mp->m_fdblocks) -
	mp->m_alloc_set_aside;
	if (free <= 0)
	break;

	delta = request - mp->m_resblks;
	lcounter = free - delta;
	if (lcounter < 0)
	/* We can't satisfy the request, just get what we can */
	fdblks_delta = free;
	else
	fdblks_delta = delta;

	/*
	* We'll either succeed in getting space 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.....
	*/
	spin_unlock(&mp->m_sb_lock);
	error = xfs_mod_fdblocks(mp, -fdblks_delta, 0);
	spin_lock(&mp->m_sb_lock);
	} while (error == -ENOSPC);

	/*
	* Update the reserve counters if blocks have been successfully
	* allocated.
	*/
	if (!error && fdblks_delta) {
	mp->m_resblks += fdblks_delta;
	mp->m_resblks_avail += fdblks_delta;
	}

	out:
	if (outval) {
	outval->resblks = mp->m_resblks;
	outval->resblks_avail = mp->m_resblks_avail;
	}

	spin_unlock(&mp->m_sb_lock);
	return error;
	}

	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 -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(
	struct xfs_mount *mp,
	int flags,
	char *fname,
	int lnnum)
	{
	bool logerror = flags & SHUTDOWN_LOG_IO_ERROR;

	/*
	* 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_FORCE_UMOUNT) {
	xfs_alert(mp,
	"User initiated shutdown received. Shutting down filesystem");
	return;
	}

	xfs_notice(mp,
	"%s(0x%x) called from line %d of file %s. Return address = "PTR_FMT,
	__func__, flags, lnnum, fname, __return_address);

	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 (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");
	}

	xfs_alert(mp,
	"Please unmount the filesystem and rectify the problem(s)");
	}

	/*
	* Reserve free space for per-AG metadata.
	*/
	int
	xfs_fs_reserve_ag_blocks(
	struct xfs_mount *mp)
	{
	xfs_agnumber_t agno;
	struct xfs_perag *pag;
	int error = 0;
	int err2;

	mp->m_finobt_nores = false;
	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
	pag = xfs_perag_get(mp, agno);
	err2 = xfs_ag_resv_init(pag, NULL);
	xfs_perag_put(pag);
	if (err2 && !error)
	error = err2;
	}

	if (error && error != -ENOSPC) {
	xfs_warn(mp,
	"Error %d reserving per-AG metadata reserve pool.", error);
	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
	}

	return error;
	}

	/*
	* Free space reserved for per-AG metadata.
	*/
	int
	xfs_fs_unreserve_ag_blocks(
	struct xfs_mount *mp)
	{
	xfs_agnumber_t agno;
	struct xfs_perag *pag;
	int error = 0;
	int err2;

	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
	pag = xfs_perag_get(mp, agno);
	err2 = xfs_ag_resv_free(pag);
	xfs_perag_put(pag);
	if (err2 && !error)
	error = err2;
	}

	if (error)
	xfs_warn(mp,
	"Error %d freeing per-AG metadata reserve pool.", error);

	return error;
	}