4.19-stable patches

added patches:
	nilfs2-fix-potential-kernel-bug-due-to-lack-of-writeback-flag-waiting.patch

diff --git a/queue-4.19/nilfs2-fix-potential-kernel-bug-due-to-lack-of-writeback-flag-waiting.patch b/queue-4.19/nilfs2-fix-potential-kernel-bug-due-to-lack-of-writeback-flag-waiting.patch
new file mode 100644 (file)
index 0000000..ae1fdf1
--- /dev/null
+++ b/queue-4.19/nilfs2-fix-potential-kernel-bug-due-to-lack-of-writeback-flag-waiting.patch
@@ -0,0 +1,76 @@
+From a4ca369ca221bb7e06c725792ac107f0e48e82e7 Mon Sep 17 00:00:00 2001
+From: Ryusuke Konishi <konishi.ryusuke@gmail.com>
+Date: Thu, 30 May 2024 23:15:56 +0900
+Subject: nilfs2: fix potential kernel bug due to lack of writeback flag waiting
+
+From: Ryusuke Konishi <konishi.ryusuke@gmail.com>
+
+commit a4ca369ca221bb7e06c725792ac107f0e48e82e7 upstream.
+
+Destructive writes to a block device on which nilfs2 is mounted can cause
+a kernel bug in the folio/page writeback start routine or writeback end
+routine (__folio_start_writeback in the log below):
+
+ kernel BUG at mm/page-writeback.c:3070!
+ Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
+ ...
+ RIP: 0010:__folio_start_writeback+0xbaa/0x10e0
+ Code: 25 ff 0f 00 00 0f 84 18 01 00 00 e8 40 ca c6 ff e9 17 f6 ff ff
+  e8 36 ca c6 ff 4c 89 f7 48 c7 c6 80 c0 12 84 e8 e7 b3 0f 00 90 <0f>
+  0b e8 1f ca c6 ff 4c 89 f7 48 c7 c6 a0 c6 12 84 e8 d0 b3 0f 00
+ ...
+ Call Trace:
+  <TASK>
+  nilfs_segctor_do_construct+0x4654/0x69d0 [nilfs2]
+  nilfs_segctor_construct+0x181/0x6b0 [nilfs2]
+  nilfs_segctor_thread+0x548/0x11c0 [nilfs2]
+  kthread+0x2f0/0x390
+  ret_from_fork+0x4b/0x80
+  ret_from_fork_asm+0x1a/0x30
+  </TASK>
+
+This is because when the log writer starts a writeback for segment summary
+blocks or a super root block that use the backing device's page cache, it
+does not wait for the ongoing folio/page writeback, resulting in an
+inconsistent writeback state.
+
+Fix this issue by waiting for ongoing writebacks when putting
+folios/pages on the backing device into writeback state.
+
+Link: https://lkml.kernel.org/r/20240530141556.4411-1-konishi.ryusuke@gmail.com
+Fixes: 9ff05123e3bf ("nilfs2: segment constructor")
+Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
+Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/nilfs2/segment.c |    3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/fs/nilfs2/segment.c
++++ b/fs/nilfs2/segment.c
+@@ -1692,6 +1692,7 @@ static void nilfs_segctor_prepare_write(
+                       if (bh->b_page != bd_page) {
+                               if (bd_page) {
+                                       lock_page(bd_page);
++                                      wait_on_page_writeback(bd_page);
+                                       clear_page_dirty_for_io(bd_page);
+                                       set_page_writeback(bd_page);
+                                       unlock_page(bd_page);
+@@ -1705,6 +1706,7 @@ static void nilfs_segctor_prepare_write(
+                       if (bh == segbuf->sb_super_root) {
+                               if (bh->b_page != bd_page) {
+                                       lock_page(bd_page);
++                                      wait_on_page_writeback(bd_page);
+                                       clear_page_dirty_for_io(bd_page);
+                                       set_page_writeback(bd_page);
+                                       unlock_page(bd_page);
+@@ -1721,6 +1723,7 @@ static void nilfs_segctor_prepare_write(
+       }
+       if (bd_page) {
+               lock_page(bd_page);
++              wait_on_page_writeback(bd_page);
+               clear_page_dirty_for_io(bd_page);
+               set_page_writeback(bd_page);
+               unlock_page(bd_page);

diff --git a/queue-4.19/series b/queue-4.19/series
index 3871a130480cf2c611f359a8e6ad06410b1cc39e..b4e8cc791c2c67da4a269caadd4fb1967c119458 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -60,3 +60,4 @@ intel_th-pci-add-granite-rapids-soc-support.patch
 intel_th-pci-add-sapphire-rapids-soc-support.patch
 intel_th-pci-add-meteor-lake-s-support.patch
 intel_th-pci-add-lunar-lake-support.patch
+nilfs2-fix-potential-kernel-bug-due-to-lack-of-writeback-flag-waiting.patch