Revision 35bf49e054214a0c7d3b0a0f8606f753f3f6ae96 authored by Lu Baolu on 23 August 2022, 06:15:57 UTC, committed by Joerg Roedel on 07 September 2022, 13:14:57 UTC
With CONFIG_INTEL_IOMMU_DEBUGFS enabled, below lockdep splat are seen
when an I/O fault occurs on a machine with an Intel IOMMU in it.

 DMAR: DRHD: handling fault status reg 3
 DMAR: [DMA Write NO_PASID] Request device [00:1a.0] fault addr 0x0
       [fault reason 0x05] PTE Write access is not set
 DMAR: Dump dmar0 table entries for IOVA 0x0
 DMAR: root entry: 0x0000000127f42001
 DMAR: context entry: hi 0x0000000000001502, low 0x000000012d8ab001
 ================================
 WARNING: inconsistent lock state
 5.20.0-0.rc0.20220812git7ebfc85e2cd7.10.fc38.x86_64 #1 Not tainted
 --------------------------------
 inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
 rngd/1006 [HC1[1]:SC0[0]:HE0:SE1] takes:
 ff177021416f2d78 (&k->k_lock){?.+.}-{2:2}, at: klist_next+0x1b/0x160
 {HARDIRQ-ON-W} state was registered at:
   lock_acquire+0xce/0x2d0
   _raw_spin_lock+0x33/0x80
   klist_add_tail+0x46/0x80
   bus_add_device+0xee/0x150
   device_add+0x39d/0x9a0
   add_memory_block+0x108/0x1d0
   memory_dev_init+0xe1/0x117
   driver_init+0x43/0x4d
   kernel_init_freeable+0x1c2/0x2cc
   kernel_init+0x16/0x140
   ret_from_fork+0x1f/0x30
 irq event stamp: 7812
 hardirqs last  enabled at (7811): [<ffffffff85000e86>] asm_sysvec_apic_timer_interrupt+0x16/0x20
 hardirqs last disabled at (7812): [<ffffffff84f16894>] irqentry_enter+0x54/0x60
 softirqs last  enabled at (7794): [<ffffffff840ff669>] __irq_exit_rcu+0xf9/0x170
 softirqs last disabled at (7787): [<ffffffff840ff669>] __irq_exit_rcu+0xf9/0x170

The klist iterator functions using spin_*lock_irq*() but the klist
insertion functions using spin_*lock(), combined with the Intel DMAR
IOMMU driver iterating over klists from atomic (hardirq) context, where
pci_get_domain_bus_and_slot() calls into bus_find_device() which iterates
over klists.

As currently there's no plan to fix the klist to make it safe to use in
atomic context, this fixes the lockdep splat by avoid calling
pci_get_domain_bus_and_slot() in the hardirq context.

Fixes: 8ac0b64b9735 ("iommu/vt-d: Use pci_get_domain_bus_and_slot() in pgtable_walk()")
Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Link: https://lore.kernel.org/linux-iommu/Yvo2dfpEh%2FWC+Wrr@wantstofly.org/
Link: https://lore.kernel.org/linux-iommu/YvyBdPwrTuHHbn5X@wantstofly.org/
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20220819015949.4795-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
1 parent a349ffc
Raw File
quota.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * quota.c - NTFS kernel quota ($Quota) handling.  Part of the Linux-NTFS
 *	     project.
 *
 * Copyright (c) 2004 Anton Altaparmakov
 */

#ifdef NTFS_RW

#include "index.h"
#include "quota.h"
#include "debug.h"
#include "ntfs.h"

/**
 * ntfs_mark_quotas_out_of_date - mark the quotas out of date on an ntfs volume
 * @vol:	ntfs volume on which to mark the quotas out of date
 *
 * Mark the quotas out of date on the ntfs volume @vol and return 'true' on
 * success and 'false' on error.
 */
bool ntfs_mark_quotas_out_of_date(ntfs_volume *vol)
{
	ntfs_index_context *ictx;
	QUOTA_CONTROL_ENTRY *qce;
	const le32 qid = QUOTA_DEFAULTS_ID;
	int err;

	ntfs_debug("Entering.");
	if (NVolQuotaOutOfDate(vol))
		goto done;
	if (!vol->quota_ino || !vol->quota_q_ino) {
		ntfs_error(vol->sb, "Quota inodes are not open.");
		return false;
	}
	inode_lock(vol->quota_q_ino);
	ictx = ntfs_index_ctx_get(NTFS_I(vol->quota_q_ino));
	if (!ictx) {
		ntfs_error(vol->sb, "Failed to get index context.");
		goto err_out;
	}
	err = ntfs_index_lookup(&qid, sizeof(qid), ictx);
	if (err) {
		if (err == -ENOENT)
			ntfs_error(vol->sb, "Quota defaults entry is not "
					"present.");
		else
			ntfs_error(vol->sb, "Lookup of quota defaults entry "
					"failed.");
		goto err_out;
	}
	if (ictx->data_len < offsetof(QUOTA_CONTROL_ENTRY, sid)) {
		ntfs_error(vol->sb, "Quota defaults entry size is invalid.  "
				"Run chkdsk.");
		goto err_out;
	}
	qce = (QUOTA_CONTROL_ENTRY*)ictx->data;
	if (le32_to_cpu(qce->version) != QUOTA_VERSION) {
		ntfs_error(vol->sb, "Quota defaults entry version 0x%x is not "
				"supported.", le32_to_cpu(qce->version));
		goto err_out;
	}
	ntfs_debug("Quota defaults flags = 0x%x.", le32_to_cpu(qce->flags));
	/* If quotas are already marked out of date, no need to do anything. */
	if (qce->flags & QUOTA_FLAG_OUT_OF_DATE)
		goto set_done;
	/*
	 * If quota tracking is neither requested, nor enabled and there are no
	 * pending deletes, no need to mark the quotas out of date.
	 */
	if (!(qce->flags & (QUOTA_FLAG_TRACKING_ENABLED |
			QUOTA_FLAG_TRACKING_REQUESTED |
			QUOTA_FLAG_PENDING_DELETES)))
		goto set_done;
	/*
	 * Set the QUOTA_FLAG_OUT_OF_DATE bit thus marking quotas out of date.
	 * This is verified on WinXP to be sufficient to cause windows to
	 * rescan the volume on boot and update all quota entries.
	 */
	qce->flags |= QUOTA_FLAG_OUT_OF_DATE;
	/* Ensure the modified flags are written to disk. */
	ntfs_index_entry_flush_dcache_page(ictx);
	ntfs_index_entry_mark_dirty(ictx);
set_done:
	ntfs_index_ctx_put(ictx);
	inode_unlock(vol->quota_q_ino);
	/*
	 * We set the flag so we do not try to mark the quotas out of date
	 * again on remount.
	 */
	NVolSetQuotaOutOfDate(vol);
done:
	ntfs_debug("Done.");
	return true;
err_out:
	if (ictx)
		ntfs_index_ctx_put(ictx);
	inode_unlock(vol->quota_q_ino);
	return false;
}

#endif /* NTFS_RW */
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