patches for 4.19

Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/queue-4.19/iomap-revert-fs-iomap.c-get-put-the-page-in-iomap_pa.patch b/queue-4.19/iomap-revert-fs-iomap.c-get-put-the-page-in-iomap_pa.patch
new file mode 100644 (file)
index 0000000..a2f5386
--- /dev/null
+++ b/queue-4.19/iomap-revert-fs-iomap.c-get-put-the-page-in-iomap_pa.patch
@@ -0,0 +1,114 @@
+From d29fcf3fdc49b06e4ae2897e5f323c235f5d8af5 Mon Sep 17 00:00:00 2001
+From: Dave Chinner <dchinner@redhat.com>
+Date: Thu, 20 Dec 2018 23:23:24 +1100
+Subject: iomap: Revert "fs/iomap.c: get/put the page in
+ iomap_page_create/release()"
+
+[ Upstream commit a837eca2412051628c0529768c9bc4f3580b040e ]
+
+This reverts commit 61c6de667263184125d5ca75e894fcad632b0dd3.
+
+The reverted commit added page reference counting to iomap page
+structures that are used to track block size < page size state. This
+was supposed to align the code with page migration page accounting
+assumptions, but what it has done instead is break XFS filesystems.
+Every fstests run I've done on sub-page block size XFS filesystems
+has since picking up this commit 2 days ago has failed with bad page
+state errors such as:
+
+# ./run_check.sh "-m rmapbt=1,reflink=1 -i sparse=1 -b size=1k" "generic/038"
+....
+SECTION       -- xfs
+FSTYP         -- xfs (debug)
+PLATFORM      -- Linux/x86_64 test1 4.20.0-rc6-dgc+
+MKFS_OPTIONS  -- -f -m rmapbt=1,reflink=1 -i sparse=1 -b size=1k /dev/sdc
+MOUNT_OPTIONS -- /dev/sdc /mnt/scratch
+
+generic/038 454s ...
+ run fstests generic/038 at 2018-12-20 18:43:05
+ XFS (sdc): Unmounting Filesystem
+ XFS (sdc): Mounting V5 Filesystem
+ XFS (sdc): Ending clean mount
+ BUG: Bad page state in process kswapd0  pfn:3a7fa
+ page:ffffea0000ccbeb0 count:0 mapcount:0 mapping:ffff88800d9b6360 index:0x1
+ flags: 0xfffffc0000000()
+ raw: 000fffffc0000000 dead000000000100 dead000000000200 ffff88800d9b6360
+ raw: 0000000000000001 0000000000000000 00000000ffffffff
+ page dumped because: non-NULL mapping
+ CPU: 0 PID: 676 Comm: kswapd0 Not tainted 4.20.0-rc6-dgc+ #915
+ Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014
+ Call Trace:
+  dump_stack+0x67/0x90
+  bad_page.cold.116+0x8a/0xbd
+  free_pcppages_bulk+0x4bf/0x6a0
+  free_unref_page_list+0x10f/0x1f0
+  shrink_page_list+0x49d/0xf50
+  shrink_inactive_list+0x19d/0x3b0
+  shrink_node_memcg.constprop.77+0x398/0x690
+  ? shrink_slab.constprop.81+0x278/0x3f0
+  shrink_node+0x7a/0x2f0
+  kswapd+0x34b/0x6d0
+  ? node_reclaim+0x240/0x240
+  kthread+0x11f/0x140
+  ? __kthread_bind_mask+0x60/0x60
+  ret_from_fork+0x24/0x30
+ Disabling lock debugging due to kernel taint
+....
+
+The failures are from anyway that frees pages and empties the
+per-cpu page magazines, so it's not a predictable failure or an easy
+to debug failure.
+
+generic/038 is a reliable reproducer of this problem - it has a 9 in
+10 failure rate on one of my test machines. Failure on other
+machines have been at random points in fstests runs but every run
+has ended up tripping this problem. Hence generic/038 was used to
+bisect the failure because it was the most reliable failure.
+
+It is too close to the 4.20 release (not to mention holidays) to
+try to diagnose, fix and test the underlying cause of the problem,
+so reverting the commit is the only option we have right now. The
+revert has been tested against a current tot 4.20-rc7+ kernel across
+multiple machines running sub-page block size XFs filesystems and
+none of the bad page state failures have been seen.
+
+Signed-off-by: Dave Chinner <dchinner@redhat.com>
+Cc: Piotr Jaroszynski <pjaroszynski@nvidia.com>
+Cc: Christoph Hellwig <hch@lst.de>
+Cc: William Kucharski <william.kucharski@oracle.com>
+Cc: Darrick J. Wong <darrick.wong@oracle.com>
+Cc: Brian Foster <bfoster@redhat.com>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ fs/iomap.c | 7 -------
+ 1 file changed, 7 deletions(-)
+
+diff --git a/fs/iomap.c b/fs/iomap.c
+index 37da7a61a6c5..ec15cf2ec696 100644
+--- a/fs/iomap.c
++++ b/fs/iomap.c
+@@ -117,12 +117,6 @@ iomap_page_create(struct inode *inode, struct page *page)
+       atomic_set(&iop->read_count, 0);
+       atomic_set(&iop->write_count, 0);
+       bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
+-
+-      /*
+-       * migrate_page_move_mapping() assumes that pages with private data have
+-       * their count elevated by 1.
+-       */
+-      get_page(page);
+       set_page_private(page, (unsigned long)iop);
+       SetPagePrivate(page);
+       return iop;
+@@ -139,7 +133,6 @@ iomap_page_release(struct page *page)
+       WARN_ON_ONCE(atomic_read(&iop->write_count));
+       ClearPagePrivate(page);
+       set_page_private(page, 0);
+-      put_page(page);
+       kfree(iop);
+ }
+ 
+-- 
+2.19.1
+

diff --git a/queue-4.19/series b/queue-4.19/series
new file mode 100644 (file)
index 0000000..18466be
--- /dev/null
+++ b/queue-4.19/series
@@ -0,0 +1 @@
+iomap-revert-fs-iomap.c-get-put-the-page-in-iomap_pa.patch