From 4ac1c17b2044a1b4b2fbed74451947e905fc2992 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 16 Jun 2016 23:26:15 +0200 Subject: [PATCH] UBIFS: Implement ->migratepage() 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(). Cc: stable@vger.kernel.org Signed-off-by: Kirill A. Shutemov [rw: Massaged changelog, build fixes, etc...] Signed-off-by: Richard Weinberger Acked-by: Christoph Hellwig --- fs/ubifs/file.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index 08316972ff93..7bbf420d1289 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -52,6 +52,7 @@ #include "ubifs.h" #include #include +#include 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 page *page) 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 ubifs_file_address_operations = { .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, }; -- 2.20.1