This is a note to let you know that I've just added the patch titled
xfs: add lock protection when remove perag from radix tree
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xfs-add-lock-protection-when-remove-perag-from-radix-tree.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable+bounces-32428-greg=kroah.com@xxxxxxxxxxxxxxx Wed Mar 27 01:13:50 2024
From: Catherine Hoang <catherine.hoang@xxxxxxxxxx>
Date: Tue, 26 Mar 2024 17:12:28 -0700
Subject: xfs: add lock protection when remove perag from radix tree
To: stable@xxxxxxxxxxxxxxx
Cc: linux-xfs@xxxxxxxxxxxxxxx
Message-ID: <20240327001233.51675-20-catherine.hoang@xxxxxxxxxx>
From: Long Li <leo.lilong@xxxxxxxxxx>
commit 07afd3173d0c6d24a47441839a835955ec6cf0d4 upstream.
Take mp->m_perag_lock for deletions from the perag radix tree in
xfs_initialize_perag to prevent racing with tagging operations.
Lookups are fine - they are RCU protected so already deal with the
tree changing shape underneath the lookup - but tagging operations
require the tree to be stable while the tags are propagated back up
to the root.
Right now there's nothing stopping radix tree tagging from operating
while a growfs operation is progress and adding/removing new entries
into the radix tree.
Hence we can have traversals that require a stable tree occurring at
the same time we are removing unused entries from the radix tree which
causes the shape of the tree to change.
Likely this hasn't caused a problem in the past because we are only
doing append addition and removal so the active AG part of the tree
is not changing shape, but that doesn't mean it is safe. Just making
the radix tree modifications serialise against each other is obviously
correct.
Signed-off-by: Long Li <leo.lilong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
Signed-off-by: Chandan Babu R <chandanbabu@xxxxxxxxxx>
Signed-off-by: Catherine Hoang <catherine.hoang@xxxxxxxxxx>
Acked-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/libxfs/xfs_ag.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/fs/xfs/libxfs/xfs_ag.c
+++ b/fs/xfs/libxfs/xfs_ag.c
@@ -424,13 +424,17 @@ xfs_initialize_perag(
out_remove_pag:
xfs_defer_drain_free(&pag->pag_intents_drain);
+ spin_lock(&mp->m_perag_lock);
radix_tree_delete(&mp->m_perag_tree, index);
+ spin_unlock(&mp->m_perag_lock);
out_free_pag:
kmem_free(pag);
out_unwind_new_pags:
/* unwind any prior newly initialized pags */
for (index = first_initialised; index < agcount; index++) {
+ spin_lock(&mp->m_perag_lock);
pag = radix_tree_delete(&mp->m_perag_tree, index);
+ spin_unlock(&mp->m_perag_lock);
if (!pag)
break;
xfs_buf_hash_destroy(pag);
Patches currently in stable-queue which might be from kroah.com@xxxxxxxxxxxxxxx are
queue-6.6/xfs-fix-32-bit-truncation-in-xfs_compute_rextslog.patch
queue-6.6/xfs-transfer-recovered-intent-item-ownership-in-iop_recover.patch
queue-6.6/xfs-initialise-di_crc-in-xfs_log_dinode.patch
queue-6.6/xfs-add-missing-nrext64-inode-flag-check-to-scrub.patch
queue-6.6/xfs-consider-minlen-sized-extents-in-xfs_rtallocate_extent_block.patch
queue-6.6/xfs-don-t-leak-recovered-attri-intent-items.patch
queue-6.6/xfs-remove-unused-fields-from-struct-xbtree_ifakeroot.patch
queue-6.6/xfs-ensure-logflagsp-is-initialized-in-xfs_bmap_del_extent_real.patch
queue-6.6/xfs-convert-rt-bitmap-extent-lengths-to-xfs_rtbxlen_t.patch
queue-6.6/xfs-fix-perag-leak-when-growfs-fails.patch
queue-6.6/xfs-pass-the-xfs_defer_pending-object-to-iop_recover.patch
queue-6.6/xfs-update-dir3-leaf-block-metadata-after-swap.patch
queue-6.6/xfs-make-rextslog-computation-consistent-with-mkfs.patch
queue-6.6/xfs-move-the-xfs_rtbitmap.c-declarations-to-xfs_rtbitmap.h.patch
queue-6.6/xfs-recompute-growfsrtfree-transaction-reservation-while-growing-rt-volume.patch
queue-6.6/xfs-force-all-buffers-to-be-written-during-btree-bulk-load.patch
queue-6.6/xfs-make-xchk_iget-safer-in-the-presence-of-corrupt-inode-btrees.patch
queue-6.6/xfs-reset-xfs_attr_incomplete-filter-on-node-removal.patch
queue-6.6/xfs-fix-an-off-by-one-error-in-xreap_agextent_binval.patch
queue-6.6/xfs-short-circuit-xfs_growfs_data_private-if-delta-is-zero.patch
queue-6.6/xfs-add-lock-protection-when-remove-perag-from-radix-tree.patch
queue-6.6/xfs-use-xfs_defer_pending-objects-to-recover-intent-items.patch
queue-6.6/xfs-don-t-allow-overly-small-or-large-realtime-volumes.patch
queue-6.6/xfs-remove-conditional-building-of-rt-geometry-validator-functions.patch
