[pve-devel] [PATCH ceph reef-stable-8] bluefs: fix OSD crash caused by incorrect alignment assertion

[Kefu Chai]

A regression was introduced in PR #62174 that added a `ceph_assert()`
statement which incorrectly assumes alloc_unit is always aligned. This
causes OSD crashes when the assertion fails.

This cherry-pick removes the faulty assertion, resolving the crash while
maintaining correct functionality for both aligned and unaligned alloc_unit
values.

Cherry-picked from: https://github.com/ceph/ceph/pull/66056

References:
- Upstream issue: https://tracker.ceph.com/issues/71235
- Introduced by: https://github.com/ceph/ceph/pull/62174

Fixes: #7211

Signed-off-by: Kefu Chai <k.chai at proxmox.com>
---
 ...BlueFS-truncate-accept-wierd-alloc_u.patch | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 patches/0018-os-bluestore-In-BlueFS-truncate-accept-wierd-alloc_u.patch

diff --git a/patches/0018-os-bluestore-In-BlueFS-truncate-accept-wierd-alloc_u.patch b/patches/0018-os-bluestore-In-BlueFS-truncate-accept-wierd-alloc_u.patch
new file mode 100644
index 00000000000..b2507924523
--- /dev/null
+++ b/patches/0018-os-bluestore-In-BlueFS-truncate-accept-wierd-alloc_u.patch
@@ -0,0 +1,41 @@
+From 87c90994b2f0c4274208028367cc8f376d0b1d6e Mon Sep 17 00:00:00 2001
+From: Adam Kupczyk <akupczyk at ibm.com>
+Date: Tue, 11 Mar 2025 10:52:15 +0000
+Subject: [PATCH] os/bluestore: In BlueFS::truncate accept wierd alloc_unit
+
+The alignment of extents might not reflect current alloc_unit[bdev].
+It might be caused be either fallback to alternate AU size for SLOW,
+or change of allocation unit in DB or WAL.
+In such cases, truncation just leaves extent untouched.
+
+Fixes: https://tracker.ceph.com/issues/71235
+
+Signed-off-by: Adam Kupczyk <akupczyk at ibm.com>
+(cherry picked from commit 0da7a2a58c207b97c9bcf4a1dfcd9d09f0e9b954)
+---
+ src/os/bluestore/BlueFS.cc | 8 +++++---
+ 1 file changed, 5 insertions(+), 3 deletions(-)
+
+diff --git a/src/os/bluestore/BlueFS.cc b/src/os/bluestore/BlueFS.cc
+index 3e7955f6433..93dc6e4753a 100644
+--- a/src/os/bluestore/BlueFS.cc
++++ b/src/os/bluestore/BlueFS.cc
+@@ -3736,10 +3736,12 @@ int BlueFS::truncate(FileWriter *h, uint64_t offset)/*_WF_L*/
+         changed_extents = true;
+         ++p;
+       } else {
+-        // cut_off > p->length means that we misaligned the extent
+-        ceph_assert(cut_off == p->length);
++        // Usually cut_off == p->length.
++        // Case cut_off > p->length means that we misaligned the extent
++        // or alloc size changed in the meantime.
++        // In both cases just leave extent untouched.
+         fnode.allocated = (offset - x_off) + p->length;
+-        ++p; // leave extent untouched
++        ++p;
+       }
+       while (p != fnode.extents.end()) {
+         dirty.pending_release[p->bdev].insert(p->offset, p->length);
+-- 
+2.47.3
+
-- 
2.47.3