4.19-stable patches

added patches:
	block-remove-special-casing-of-compound-pages.patch

diff --git a/queue-4.19/block-remove-special-casing-of-compound-pages.patch b/queue-4.19/block-remove-special-casing-of-compound-pages.patch
new file mode 100644 (file)
index 0000000..4623a32
--- /dev/null
+++ b/queue-4.19/block-remove-special-casing-of-compound-pages.patch
@@ -0,0 +1,70 @@
+From 0f2dca516541032fe47a1236c852f58edc662795 Mon Sep 17 00:00:00 2001
+From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
+Date: Mon, 14 Aug 2023 15:41:00 +0100
+Subject: block: Remove special-casing of compound pages
+
+From: Matthew Wilcox (Oracle) <willy@infradead.org>
+
+commit 1b151e2435fc3a9b10c8946c6aebe9f3e1938c55 upstream.
+
+The special casing was originally added in pre-git history; reproducing
+the commit log here:
+
+> commit a318a92567d77
+> Author: Andrew Morton <akpm@osdl.org>
+> Date:   Sun Sep 21 01:42:22 2003 -0700
+>
+>     [PATCH] Speed up direct-io hugetlbpage handling
+>
+>     This patch short-circuits all the direct-io page dirtying logic for
+>     higher-order pages.  Without this, we pointlessly bounce BIOs up to
+>     keventd all the time.
+
+In the last twenty years, compound pages have become used for more than
+just hugetlb.  Rewrite these functions to operate on folios instead
+of pages and remove the special case for hugetlbfs; I don't think
+it's needed any more (and if it is, we can put it back in as a call
+to folio_test_hugetlb()).
+
+This was found by inspection; as far as I can tell, this bug can lead
+to pages used as the destination of a direct I/O read not being marked
+as dirty.  If those pages are then reclaimed by the MM without being
+dirtied for some other reason, they won't be written out.  Then when
+they're faulted back in, they will not contain the data they should.
+It'll take a pretty unusual setup to produce this problem with several
+races all going the wrong way.
+
+This problem predates the folio work; it could for example have been
+triggered by mmaping a THP in tmpfs and using that as the target of an
+O_DIRECT read.
+
+Fixes: 800d8c63b2e98 ("shmem: add huge pages support")
+Cc:  <stable@vger.kernel.org>
+Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ block/bio.c |    5 ++---
+ 1 file changed, 2 insertions(+), 3 deletions(-)
+
+--- a/block/bio.c
++++ b/block/bio.c
+@@ -1592,8 +1592,7 @@ void bio_set_pages_dirty(struct bio *bio
+       int i;
+ 
+       bio_for_each_segment_all(bvec, bio, i) {
+-              if (!PageCompound(bvec->bv_page))
+-                      set_page_dirty_lock(bvec->bv_page);
++              set_page_dirty_lock(bvec->bv_page);
+       }
+ }
+ EXPORT_SYMBOL_GPL(bio_set_pages_dirty);
+@@ -1652,7 +1651,7 @@ void bio_check_pages_dirty(struct bio *b
+       int i;
+ 
+       bio_for_each_segment_all(bvec, bio, i) {
+-              if (!PageDirty(bvec->bv_page) && !PageCompound(bvec->bv_page))
++              if (!PageDirty(bvec->bv_page))
+                       goto defer;
+       }
+ 

diff --git a/queue-4.19/series b/queue-4.19/series
index c40dc143f380f645ee4d35268c14154b4654cc6f..12074fb3a121c870cfa3ebaaef126e79cc01820e 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -14,3 +14,4 @@ hwrng-core-fix-page-fault-dead-lock-on-mmap-ed-hwrng.patch
 rpmsg-virtio-free-driver_override-when-rpmsg_remove.patch
 parisc-firmware-fix-f-extend-for-pdc-addresses.patch
 nouveau-vmm-don-t-set-addr-on-the-fail-path-to-avoid-warning.patch
+block-remove-special-casing-of-compound-pages.patch