From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933370AbcHNLXH (ORCPT ); Sun, 14 Aug 2016 07:23:07 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51891 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932562AbcHNK75 (ORCPT ); Sun, 14 Aug 2016 06:59:57 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Kirill A. Shutemov" , "Richard Weinberger" , "Christoph Hellwig" Date: Sat, 13 Aug 2016 18:42:51 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 210/305] UBIFS: Implement ->migratepage() In-Reply-To: X-SA-Exim-Connect-IP: 92.40.249.202 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "Kirill A. Shutemov" 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] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [ 213.490000] [] (show_stack) from [] (dump_stack+0x8c/0xa0) [ 213.490000] [] (dump_stack) from [] (ubifs_set_page_dirty+0x44/0x50) [ 213.490000] [] (ubifs_set_page_dirty) from [] (try_to_unmap_one+0x10c/0x3a8) [ 213.490000] [] (try_to_unmap_one) from [] (rmap_walk+0xb4/0x290) [ 213.490000] [] (rmap_walk) from [] (try_to_unmap+0x64/0x80) [ 213.490000] [] (try_to_unmap) from [] (migrate_pages+0x328/0x7a0) [ 213.490000] [] (migrate_pages) from [] (alloc_contig_range+0x168/0x2f4) [ 213.490000] [] (alloc_contig_range) from [] (cma_alloc+0x170/0x2c0) [ 213.490000] [] (cma_alloc) from [] (__alloc_from_contiguous+0x38/0xd8) [ 213.490000] [] (__alloc_from_contiguous) from [] (__dma_alloc+0x23c/0x274) [ 213.490000] [] (__dma_alloc) from [] (arm_dma_alloc+0x54/0x5c) [ 213.490000] [] (arm_dma_alloc) from [] (drm_gem_cma_create+0xb8/0xf0) [ 213.490000] [] (drm_gem_cma_create) from [] (drm_gem_cma_create_with_handle+0x1c/0xe8) [ 213.490000] [] (drm_gem_cma_create_with_handle) from [] (drm_gem_cma_dumb_create+0x3c/0x48) [ 213.490000] [] (drm_gem_cma_dumb_create) from [] (drm_ioctl+0x12c/0x444) [ 213.490000] [] (drm_ioctl) from [] (do_vfs_ioctl+0x3f4/0x614) [ 213.490000] [] (do_vfs_ioctl) from [] (SyS_ioctl+0x34/0x5c) [ 213.490000] [] (SyS_ioctl) from [] (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 [rw: Massaged changelog, build fixes, etc...] Signed-off-by: Richard Weinberger Acked-by: Christoph Hellwig Signed-off-by: Ben Hutchings --- fs/ubifs/file.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -54,6 +54,7 @@ #include #include #include +#include static int read_block(struct inode *inode, void *addr, unsigned int block, struct ubifs_data_node *dn) @@ -1419,6 +1420,26 @@ 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) { /* @@ -1556,6 +1577,9 @@ 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, };