1 files changed, 235 insertions, 0 deletions
diff --git a/fs/xfs/xfs_notify_failure.c b/fs/xfs/xfs_notify_failure.c
new file mode 100644
index 0000000000..a7daa522e0
--- /dev/null
+++ b/fs/xfs/xfs_notify_failure.c
@@ -0,0 +1,235 @@
+// 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>
+
+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;
+	int				error = 0;
+
+	if (XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) ||
+	    (rec->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK))) {
+		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;
+	}
+
+	error = mf_dax_kill_procs(VFS_I(ip)->i_mapping,
+				  xfs_failure_pgoff(mp, rec, notify),
+				  xfs_failure_pgcnt(mp, rec, notify),
+				  notify->mf_flags);
+	xfs_irele(ip);
+	return error;
+}
+
+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;
+	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);
+
+	error = xfs_trans_alloc_empty(mp, &tp);
+	if (error)
+		return error;
+
+	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);
+	if (error || notify.want_shutdown) {
+		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK);
+		if (!error)
+			error = -EFSCORRUPTED;
+	}
+	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) {
+		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;
+
+	/* 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,
+};