This is a note to let you know that I've just added the patch titled
UBIFS: Implement ->migratepage()
to the 4.4-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:
ubifs-implement-migratepage.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4ac1c17b2044a1b4b2fbed74451947e905fc2992 Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Date: Thu, 16 Jun 2016 23:26:15 +0200
Subject: UBIFS: Implement ->migratepage()
From: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
commit 4ac1c17b2044a1b4b2fbed74451947e905fc2992 upstream.
During page migrations UBIFS might get confused
and the following assert triggers:
[ 213.480000] UBIFS assert failed in ubifs_set_page_dirty at 1451 (pid 436)
[ 213.490000] CPU: 0 PID: 436 Comm: drm-stress-test Not tainted 4.4.4-00176-geaa802524636-dirty #1008
[ 213.490000] Hardware name: Allwinner sun4i/sun5i Families
[ 213.490000] [<c0015e70>] (unwind_backtrace) from [<c0012cdc>] (show_stack+0x10/0x14)
[ 213.490000] [<c0012cdc>] (show_stack) from [<c02ad834>] (dump_stack+0x8c/0xa0)
[ 213.490000] [<c02ad834>] (dump_stack) from [<c0236ee8>] (ubifs_set_page_dirty+0x44/0x50)
[ 213.490000] [<c0236ee8>] (ubifs_set_page_dirty) from [<c00fa0bc>] (try_to_unmap_one+0x10c/0x3a8)
[ 213.490000] [<c00fa0bc>] (try_to_unmap_one) from [<c00fadb4>] (rmap_walk+0xb4/0x290)
[ 213.490000] [<c00fadb4>] (rmap_walk) from [<c00fb1bc>] (try_to_unmap+0x64/0x80)
[ 213.490000] [<c00fb1bc>] (try_to_unmap) from [<c010dc28>] (migrate_pages+0x328/0x7a0)
[ 213.490000] [<c010dc28>] (migrate_pages) from [<c00d0cb0>] (alloc_contig_range+0x168/0x2f4)
[ 213.490000] [<c00d0cb0>] (alloc_contig_range) from [<c010ec00>] (cma_alloc+0x170/0x2c0)
[ 213.490000] [<c010ec00>] (cma_alloc) from [<c001a958>] (__alloc_from_contiguous+0x38/0xd8)
[ 213.490000] [<c001a958>] (__alloc_from_contiguous) from [<c001ad44>] (__dma_alloc+0x23c/0x274)
[ 213.490000] [<c001ad44>] (__dma_alloc) from [<c001ae08>] (arm_dma_alloc+0x54/0x5c)
[ 213.490000] [<c001ae08>] (arm_dma_alloc) from [<c035cecc>] (drm_gem_cma_create+0xb8/0xf0)
[ 213.490000] [<c035cecc>] (drm_gem_cma_create) from [<c035cf20>] (drm_gem_cma_create_with_handle+0x1c/0xe8)
[ 213.490000] [<c035cf20>] (drm_gem_cma_create_with_handle) from [<c035d088>] (drm_gem_cma_dumb_create+0x3c/0x48)
[ 213.490000] [<c035d088>] (drm_gem_cma_dumb_create) from [<c0341ed8>] (drm_ioctl+0x12c/0x444)
[ 213.490000] [<c0341ed8>] (drm_ioctl) from [<c0121adc>] (do_vfs_ioctl+0x3f4/0x614)
[ 213.490000] [<c0121adc>] (do_vfs_ioctl) from [<c0121d30>] (SyS_ioctl+0x34/0x5c)
[ 213.490000] [<c0121d30>] (SyS_ioctl) from [<c000f2c0>] (ret_fast_syscall+0x0/0x34)
UBIFS is using PagePrivate() which can have different meanings across
filesystems. Therefore the generic page migration code cannot handle this
case correctly.
We have to implement our own migration function which basically does a
plain copy but also duplicates the page private flag.
UBIFS is not a block device filesystem and cannot use buffer_migrate_page().
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
[rw: Massaged changelog, build fixes, etc...]
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Acked-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ubifs/file.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -52,6 +52,7 @@
#include "ubifs.h"
#include <linux/mount.h>
#include <linux/slab.h>
+#include <linux/migrate.h>
static int read_block(struct inode *inode, void *addr, unsigned int block,
struct ubifs_data_node *dn)
@@ -1452,6 +1453,26 @@ static int ubifs_set_page_dirty(struct p
return ret;
}
+#ifdef CONFIG_MIGRATION
+static int ubifs_migrate_page(struct address_space *mapping,
+ struct page *newpage, struct page *page, enum migrate_mode mode)
+{
+ int rc;
+
+ rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0);
+ if (rc != MIGRATEPAGE_SUCCESS)
+ return rc;
+
+ if (PagePrivate(page)) {
+ ClearPagePrivate(page);
+ SetPagePrivate(newpage);
+ }
+
+ migrate_page_copy(newpage, page);
+ return MIGRATEPAGE_SUCCESS;
+}
+#endif
+
static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags)
{
/*
@@ -1591,6 +1612,9 @@ const struct address_space_operations ub
.write_end = ubifs_write_end,
.invalidatepage = ubifs_invalidatepage,
.set_page_dirty = ubifs_set_page_dirty,
+#ifdef CONFIG_MIGRATION
+ .migratepage = ubifs_migrate_page,
+#endif
.releasepage = ubifs_releasepage,
};
Patches currently in stable-queue which might be from kirill.shutemov@xxxxxxxxxxxxxxx are
queue-4.4/ubifs-implement-migratepage.patch
queue-4.4/arm-8579-1-mm-fix-definition-of-pmd_mknotpresent.patch
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