fs/xfs/xfs_notify_failure.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2022 Fujitsu.  All Rights Reserved.
  */

 #include "xfs.h"
 #include "xfs_shared.h"
 #include "xfs_format.h"
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_mount.h"
 #include "xfs_alloc.h"
 #include "xfs_bit.h"
 #include "xfs_btree.h"
 #include "xfs_inode.h"
 #include "xfs_icache.h"
 #include "xfs_rmap.h"
 #include "xfs_rmap_btree.h"
 #include "xfs_rtalloc.h"
 #include "xfs_trans.h"
 #include "xfs_ag.h"

 #include <linux/mm.h>
 #include <linux/dax.h>
 #include <linux/fs.h>

 struct xfs_failure_info {
 	xfs_agblock_t		startblock;
 	xfs_extlen_t		blockcount;
 	int			mf_flags;
 	bool			want_shutdown;
 };

 static pgoff_t
 xfs_failure_pgoff(
 	struct xfs_mount		*mp,
 	const struct xfs_rmap_irec	*rec,
 	const struct xfs_failure_info	*notify)
 {
 	loff_t				pos = XFS_FSB_TO_B(mp, rec->rm_offset);

 	if (notify->startblock > rec->rm_startblock)
 		pos += XFS_FSB_TO_B(mp,
 				notify->startblock - rec->rm_startblock);
 	return pos >> PAGE_SHIFT;
 }

 static unsigned long
 xfs_failure_pgcnt(
 	struct xfs_mount		*mp,
 	const struct xfs_rmap_irec	*rec,
 	const struct xfs_failure_info	*notify)
 {
 	xfs_agblock_t			end_rec;
 	xfs_agblock_t			end_notify;
 	xfs_agblock_t			start_cross;
 	xfs_agblock_t			end_cross;

 	start_cross = max(rec->rm_startblock, notify->startblock);

 	end_rec = rec->rm_startblock + rec->rm_blockcount;
 	end_notify = notify->startblock + notify->blockcount;
 	end_cross = min(end_rec, end_notify);

 	return XFS_FSB_TO_B(mp, end_cross - start_cross) >> PAGE_SHIFT;
 }

 static int
 xfs_dax_failure_fn(
 	struct xfs_btree_cur		*cur,
 	const struct xfs_rmap_irec	*rec,
 	void				*data)
 {
 	struct xfs_mount		*mp = cur->bc_mp;
 	struct xfs_inode		*ip;
 	struct xfs_failure_info		*notify = data;
 	struct address_space		*mapping;
 	pgoff_t				pgoff;
 	unsigned long			pgcnt;
 	int				error = 0;

 	if (XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) ||
 	    (rec->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK))) {
 		/* Continue the query because this isn't a failure. */
 		if (notify->mf_flags & MF_MEM_PRE_REMOVE)
 			return 0;
 		notify->want_shutdown = true;
 		return 0;
 	}

 	/* Get files that incore, filter out others that are not in use. */
 	error = xfs_iget(mp, cur->bc_tp, rec->rm_owner, XFS_IGET_INCORE,
 			 0, &ip);
 	/* Continue the rmap query if the inode isn't incore */
 	if (error == -ENODATA)
 		return 0;
 	if (error) {
 		notify->want_shutdown = true;
 		return 0;
 	}

 	mapping = VFS_I(ip)->i_mapping;
 	pgoff = xfs_failure_pgoff(mp, rec, notify);
 	pgcnt = xfs_failure_pgcnt(mp, rec, notify);

 	/* Continue the rmap query if the inode isn't a dax file. */
 	if (dax_mapping(mapping))
 		error = mf_dax_kill_procs(mapping, pgoff, pgcnt,
 					  notify->mf_flags);

 	/* Invalidate the cache in dax pages. */
 	if (notify->mf_flags & MF_MEM_PRE_REMOVE)
 		invalidate_inode_pages2_range(mapping, pgoff,
 					      pgoff + pgcnt - 1);

 	xfs_irele(ip);
 	return error;
 }

 static int
 xfs_dax_notify_failure_freeze(
 	struct xfs_mount	*mp)
 {
 	struct super_block	*sb = mp->m_super;
 	int			error;

 	error = freeze_super(sb, FREEZE_HOLDER_KERNEL);
 	if (error)
 		xfs_emerg(mp, "already frozen by kernel, err=%d", error);

 	return error;
 }

 static void
 xfs_dax_notify_failure_thaw(
 	struct xfs_mount	*mp,
 	bool			kernel_frozen)
 {
 	struct super_block	*sb = mp->m_super;
 	int			error;

 	if (kernel_frozen) {
 		error = thaw_super(sb, FREEZE_HOLDER_KERNEL);
 		if (error)
 			xfs_emerg(mp, "still frozen after notify failure, err=%d",
 				error);
 	}

 	/*
 	 * Also thaw userspace call anyway because the device is about to be
 	 * removed immediately.
 	 */
 	thaw_super(sb, FREEZE_HOLDER_USERSPACE);
 }

 static int
 xfs_dax_notify_ddev_failure(
 	struct xfs_mount	*mp,
 	xfs_daddr_t		daddr,
 	xfs_daddr_t		bblen,
 	int			mf_flags)
 {
 	struct xfs_failure_info	notify = { .mf_flags = mf_flags };
 	struct xfs_trans	*tp = NULL;
 	struct xfs_btree_cur	*cur = NULL;
 	struct xfs_buf		*agf_bp = NULL;
 	int			error = 0;
 	bool			kernel_frozen = false;
 	xfs_fsblock_t		fsbno = XFS_DADDR_TO_FSB(mp, daddr);
 	xfs_agnumber_t		agno = XFS_FSB_TO_AGNO(mp, fsbno);
 	xfs_fsblock_t		end_fsbno = XFS_DADDR_TO_FSB(mp,
 							     daddr + bblen - 1);
 	xfs_agnumber_t		end_agno = XFS_FSB_TO_AGNO(mp, end_fsbno);

 	if (mf_flags & MF_MEM_PRE_REMOVE) {
 		xfs_info(mp, "Device is about to be removed!");
 		/*
 		 * Freeze fs to prevent new mappings from being created.
 		 * - Keep going on if others already hold the kernel forzen.
 		 * - Keep going on if other errors too because this device is
 		 *   starting to fail.
 		 * - If kernel frozen state is hold successfully here, thaw it
 		 *   here as well at the end.
 		 */
 		kernel_frozen = xfs_dax_notify_failure_freeze(mp) == 0;
 	}

 	error = xfs_trans_alloc_empty(mp, &tp);
 	if (error)
 		goto out;

 	for (; agno <= end_agno; agno++) {
 		struct xfs_rmap_irec	ri_low = { };
 		struct xfs_rmap_irec	ri_high;
 		struct xfs_agf		*agf;
 		struct xfs_perag	*pag;
 		xfs_agblock_t		range_agend;

 		pag = xfs_perag_get(mp, agno);
 		error = xfs_alloc_read_agf(pag, tp, 0, &agf_bp);
 		if (error) {
 			xfs_perag_put(pag);
 			break;
 		}

 		cur = xfs_rmapbt_init_cursor(mp, tp, agf_bp, pag);

 		/*
 		 * Set the rmap range from ri_low to ri_high, which represents
 		 * a [start, end] where we looking for the files or metadata.
 		 */
 		memset(&ri_high, 0xFF, sizeof(ri_high));
 		ri_low.rm_startblock = XFS_FSB_TO_AGBNO(mp, fsbno);
 		if (agno == end_agno)
 			ri_high.rm_startblock = XFS_FSB_TO_AGBNO(mp, end_fsbno);

 		agf = agf_bp->b_addr;
 		range_agend = min(be32_to_cpu(agf->agf_length) - 1,
 				ri_high.rm_startblock);
 		notify.startblock = ri_low.rm_startblock;
 		notify.blockcount = range_agend + 1 - ri_low.rm_startblock;

 		error = xfs_rmap_query_range(cur, &ri_low, &ri_high,
 				xfs_dax_failure_fn, &notify);
 		xfs_btree_del_cursor(cur, error);
 		xfs_trans_brelse(tp, agf_bp);
 		xfs_perag_put(pag);
 		if (error)
 			break;

 		fsbno = XFS_AGB_TO_FSB(mp, agno + 1, 0);
 	}

 	xfs_trans_cancel(tp);

 	/*
 	 * Shutdown fs from a force umount in pre-remove case which won't fail,
 	 * so errors can be ignored.  Otherwise, shutdown the filesystem with
 	 * CORRUPT flag if error occured or notify.want_shutdown was set during
 	 * RMAP querying.
 	 */
 	if (mf_flags & MF_MEM_PRE_REMOVE)
 		xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
 	else if (error || notify.want_shutdown) {
 		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK);
 		if (!error)
 			error = -EFSCORRUPTED;
 	}

 out:
 	/* Thaw the fs if it has been frozen before. */
 	if (mf_flags & MF_MEM_PRE_REMOVE)
 		xfs_dax_notify_failure_thaw(mp, kernel_frozen);

 	return error;
 }

 static int
 xfs_dax_notify_failure(
 	struct dax_device	*dax_dev,
 	u64			offset,
 	u64			len,
 	int			mf_flags)
 {
 	struct xfs_mount	*mp = dax_holder(dax_dev);
 	u64			ddev_start;
 	u64			ddev_end;

 	if (!(mp->m_super->s_flags & SB_BORN)) {
 		xfs_warn(mp, "filesystem is not ready for notify_failure()!");
 		return -EIO;
 	}

 	if (mp->m_rtdev_targp && mp->m_rtdev_targp->bt_daxdev == dax_dev) {
 		xfs_debug(mp,
 			 "notify_failure() not supported on realtime device!");
 		return -EOPNOTSUPP;
 	}

 	if (mp->m_logdev_targp && mp->m_logdev_targp->bt_daxdev == dax_dev &&
 	    mp->m_logdev_targp != mp->m_ddev_targp) {
 		/*
 		 * In the pre-remove case the failure notification is attempting
 		 * to trigger a force unmount.  The expectation is that the
 		 * device is still present, but its removal is in progress and
 		 * can not be cancelled, proceed with accessing the log device.
 		 */
 		if (mf_flags & MF_MEM_PRE_REMOVE)
 			return 0;
 		xfs_err(mp, "ondisk log corrupt, shutting down fs!");
 		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK);
 		return -EFSCORRUPTED;
 	}

 	if (!xfs_has_rmapbt(mp)) {
 		xfs_debug(mp, "notify_failure() needs rmapbt enabled!");
 		return -EOPNOTSUPP;
 	}

 	ddev_start = mp->m_ddev_targp->bt_dax_part_off;
 	ddev_end = ddev_start + bdev_nr_bytes(mp->m_ddev_targp->bt_bdev) - 1;

 	/* Notify failure on the whole device. */
 	if (offset == 0 && len == U64_MAX) {
 		offset = ddev_start;
 		len = bdev_nr_bytes(mp->m_ddev_targp->bt_bdev);
 	}

 	/* Ignore the range out of filesystem area */
 	if (offset + len - 1 < ddev_start)
 		return -ENXIO;
 	if (offset > ddev_end)
 		return -ENXIO;

 	/* Calculate the real range when it touches the boundary */
 	if (offset > ddev_start)
 		offset -= ddev_start;
 	else {
 		len -= ddev_start - offset;
 		offset = 0;
 	}
 	if (offset + len - 1 > ddev_end)
 		len = ddev_end - offset + 1;

 	return xfs_dax_notify_ddev_failure(mp, BTOBB(offset), BTOBB(len),
 			mf_flags);
 }

 const struct dax_holder_operations xfs_dax_holder_operations = {
 	.notify_failure		= xfs_dax_notify_failure,
 };
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (c) 2022 Fujitsu. All Rights Reserved.
	*/

	#include "xfs.h"
	#include "xfs_shared.h"
	#include "xfs_format.h"
	#include "xfs_log_format.h"
	#include "xfs_trans_resv.h"
	#include "xfs_mount.h"
	#include "xfs_alloc.h"
	#include "xfs_bit.h"
	#include "xfs_btree.h"
	#include "xfs_inode.h"
	#include "xfs_icache.h"
	#include "xfs_rmap.h"
	#include "xfs_rmap_btree.h"
	#include "xfs_rtalloc.h"
	#include "xfs_trans.h"
	#include "xfs_ag.h"

	#include <linux/mm.h>
	#include <linux/dax.h>
	#include <linux/fs.h>

	struct xfs_failure_info {
	xfs_agblock_t startblock;
	xfs_extlen_t blockcount;
	int mf_flags;
	bool want_shutdown;
	};

	static pgoff_t
	xfs_failure_pgoff(
	struct xfs_mount *mp,
	const struct xfs_rmap_irec *rec,
	const struct xfs_failure_info *notify)
	{
	loff_t pos = XFS_FSB_TO_B(mp, rec->rm_offset);

	if (notify->startblock > rec->rm_startblock)
	pos += XFS_FSB_TO_B(mp,
	notify->startblock - rec->rm_startblock);
	return pos >> PAGE_SHIFT;
	}

	static unsigned long
	xfs_failure_pgcnt(
	struct xfs_mount *mp,
	const struct xfs_rmap_irec *rec,
	const struct xfs_failure_info *notify)
	{
	xfs_agblock_t end_rec;
	xfs_agblock_t end_notify;
	xfs_agblock_t start_cross;
	xfs_agblock_t end_cross;

	start_cross = max(rec->rm_startblock, notify->startblock);

	end_rec = rec->rm_startblock + rec->rm_blockcount;
	end_notify = notify->startblock + notify->blockcount;
	end_cross = min(end_rec, end_notify);

	return XFS_FSB_TO_B(mp, end_cross - start_cross) >> PAGE_SHIFT;
	}

	static int
	xfs_dax_failure_fn(
	struct xfs_btree_cur *cur,
	const struct xfs_rmap_irec *rec,
	void *data)
	{
	struct xfs_mount *mp = cur->bc_mp;
	struct xfs_inode *ip;
	struct xfs_failure_info *notify = data;
	struct address_space *mapping;
	pgoff_t pgoff;
	unsigned long pgcnt;
	int error = 0;

	if (XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) \|\|
	(rec->rm_flags & (XFS_RMAP_ATTR_FORK \| XFS_RMAP_BMBT_BLOCK))) {
	/* Continue the query because this isn't a failure. */
	if (notify->mf_flags & MF_MEM_PRE_REMOVE)
	return 0;
	notify->want_shutdown = true;
	return 0;
	}

	/* Get files that incore, filter out others that are not in use. */
	error = xfs_iget(mp, cur->bc_tp, rec->rm_owner, XFS_IGET_INCORE,
	0, &ip);
	/* Continue the rmap query if the inode isn't incore */
	if (error == -ENODATA)
	return 0;
	if (error) {
	notify->want_shutdown = true;
	return 0;
	}

	mapping = VFS_I(ip)->i_mapping;
	pgoff = xfs_failure_pgoff(mp, rec, notify);
	pgcnt = xfs_failure_pgcnt(mp, rec, notify);

	/* Continue the rmap query if the inode isn't a dax file. */
	if (dax_mapping(mapping))
	error = mf_dax_kill_procs(mapping, pgoff, pgcnt,
	notify->mf_flags);

	/* Invalidate the cache in dax pages. */
	if (notify->mf_flags & MF_MEM_PRE_REMOVE)
	invalidate_inode_pages2_range(mapping, pgoff,
	pgoff + pgcnt - 1);

	xfs_irele(ip);
	return error;
	}

	static int
	xfs_dax_notify_failure_freeze(
	struct xfs_mount *mp)
	{
	struct super_block *sb = mp->m_super;
	int error;

	error = freeze_super(sb, FREEZE_HOLDER_KERNEL);
	if (error)
	xfs_emerg(mp, "already frozen by kernel, err=%d", error);

	return error;
	}

	static void
	xfs_dax_notify_failure_thaw(
	struct xfs_mount *mp,
	bool kernel_frozen)
	{
	struct super_block *sb = mp->m_super;
	int error;

	if (kernel_frozen) {
	error = thaw_super(sb, FREEZE_HOLDER_KERNEL);
	if (error)
	xfs_emerg(mp, "still frozen after notify failure, err=%d",
	error);
	}

	/*
	* Also thaw userspace call anyway because the device is about to be
	* removed immediately.
	*/
	thaw_super(sb, FREEZE_HOLDER_USERSPACE);
	}

	static int
	xfs_dax_notify_ddev_failure(
	struct xfs_mount *mp,
	xfs_daddr_t daddr,
	xfs_daddr_t bblen,
	int mf_flags)
	{
	struct xfs_failure_info notify = { .mf_flags = mf_flags };
	struct xfs_trans *tp = NULL;
	struct xfs_btree_cur *cur = NULL;
	struct xfs_buf *agf_bp = NULL;
	int error = 0;
	bool kernel_frozen = false;
	xfs_fsblock_t fsbno = XFS_DADDR_TO_FSB(mp, daddr);
	xfs_agnumber_t agno = XFS_FSB_TO_AGNO(mp, fsbno);
	xfs_fsblock_t end_fsbno = XFS_DADDR_TO_FSB(mp,
	daddr + bblen - 1);
	xfs_agnumber_t end_agno = XFS_FSB_TO_AGNO(mp, end_fsbno);

	if (mf_flags & MF_MEM_PRE_REMOVE) {
	xfs_info(mp, "Device is about to be removed!");
	/*
	* Freeze fs to prevent new mappings from being created.
	* - Keep going on if others already hold the kernel forzen.
	* - Keep going on if other errors too because this device is
	* starting to fail.
	* - If kernel frozen state is hold successfully here, thaw it
	* here as well at the end.
	*/
	kernel_frozen = xfs_dax_notify_failure_freeze(mp) == 0;
	}

	error = xfs_trans_alloc_empty(mp, &tp);
	if (error)
	goto out;

	for (; agno <= end_agno; agno++) {
	struct xfs_rmap_irec ri_low = { };
	struct xfs_rmap_irec ri_high;
	struct xfs_agf *agf;
	struct xfs_perag *pag;
	xfs_agblock_t range_agend;

	pag = xfs_perag_get(mp, agno);
	error = xfs_alloc_read_agf(pag, tp, 0, &agf_bp);
	if (error) {
	xfs_perag_put(pag);
	break;
	}

	cur = xfs_rmapbt_init_cursor(mp, tp, agf_bp, pag);

	/*
	* Set the rmap range from ri_low to ri_high, which represents
	* a [start, end] where we looking for the files or metadata.
	*/
	memset(&ri_high, 0xFF, sizeof(ri_high));
	ri_low.rm_startblock = XFS_FSB_TO_AGBNO(mp, fsbno);
	if (agno == end_agno)
	ri_high.rm_startblock = XFS_FSB_TO_AGBNO(mp, end_fsbno);

	agf = agf_bp->b_addr;
	range_agend = min(be32_to_cpu(agf->agf_length) - 1,
	ri_high.rm_startblock);
	notify.startblock = ri_low.rm_startblock;
	notify.blockcount = range_agend + 1 - ri_low.rm_startblock;

	error = xfs_rmap_query_range(cur, &ri_low, &ri_high,
	xfs_dax_failure_fn, &notify);
	xfs_btree_del_cursor(cur, error);
	xfs_trans_brelse(tp, agf_bp);
	xfs_perag_put(pag);
	if (error)
	break;

	fsbno = XFS_AGB_TO_FSB(mp, agno + 1, 0);
	}

	xfs_trans_cancel(tp);

	/*
	* Shutdown fs from a force umount in pre-remove case which won't fail,
	* so errors can be ignored. Otherwise, shutdown the filesystem with
	* CORRUPT flag if error occured or notify.want_shutdown was set during
	* RMAP querying.
	*/
	if (mf_flags & MF_MEM_PRE_REMOVE)
	xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
	else if (error \|\| notify.want_shutdown) {
	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK);
	if (!error)
	error = -EFSCORRUPTED;
	}

	out:
	/* Thaw the fs if it has been frozen before. */
	if (mf_flags & MF_MEM_PRE_REMOVE)
	xfs_dax_notify_failure_thaw(mp, kernel_frozen);

	return error;
	}

	static int
	xfs_dax_notify_failure(
	struct dax_device *dax_dev,
	u64 offset,
	u64 len,
	int mf_flags)
	{
	struct xfs_mount *mp = dax_holder(dax_dev);
	u64 ddev_start;
	u64 ddev_end;

	if (!(mp->m_super->s_flags & SB_BORN)) {
	xfs_warn(mp, "filesystem is not ready for notify_failure()!");
	return -EIO;
	}

	if (mp->m_rtdev_targp && mp->m_rtdev_targp->bt_daxdev == dax_dev) {
	xfs_debug(mp,
	"notify_failure() not supported on realtime device!");
	return -EOPNOTSUPP;
	}

	if (mp->m_logdev_targp && mp->m_logdev_targp->bt_daxdev == dax_dev &&
	mp->m_logdev_targp != mp->m_ddev_targp) {
	/*
	* In the pre-remove case the failure notification is attempting
	* to trigger a force unmount. The expectation is that the
	* device is still present, but its removal is in progress and
	* can not be cancelled, proceed with accessing the log device.
	*/
	if (mf_flags & MF_MEM_PRE_REMOVE)
	return 0;
	xfs_err(mp, "ondisk log corrupt, shutting down fs!");
	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK);
	return -EFSCORRUPTED;
	}

	if (!xfs_has_rmapbt(mp)) {
	xfs_debug(mp, "notify_failure() needs rmapbt enabled!");
	return -EOPNOTSUPP;
	}

	ddev_start = mp->m_ddev_targp->bt_dax_part_off;
	ddev_end = ddev_start + bdev_nr_bytes(mp->m_ddev_targp->bt_bdev) - 1;

	/* Notify failure on the whole device. */
	if (offset == 0 && len == U64_MAX) {
	offset = ddev_start;
	len = bdev_nr_bytes(mp->m_ddev_targp->bt_bdev);
	}

	/* Ignore the range out of filesystem area */
	if (offset + len - 1 < ddev_start)
	return -ENXIO;
	if (offset > ddev_end)
	return -ENXIO;

	/* Calculate the real range when it touches the boundary */
	if (offset > ddev_start)
	offset -= ddev_start;
	else {
	len -= ddev_start - offset;
	offset = 0;
	}
	if (offset + len - 1 > ddev_end)
	len = ddev_end - offset + 1;

	return xfs_dax_notify_ddev_failure(mp, BTOBB(offset), BTOBB(len),
	mf_flags);
	}

	const struct dax_holder_operations xfs_dax_holder_operations = {
	.notify_failure = xfs_dax_notify_failure,
	};