diff --git a/fs/block_dev.c b/fs/block_dev.c index 85f5c85ec91c..4e9b5f49c5bf 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1590,6 +1590,7 @@ static const struct address_space_operations def_blk_aops = { .writepages = generic_writepages, .releasepage = blkdev_releasepage, .direct_IO = blkdev_direct_IO, + .is_dirty_writeback = buffer_check_dirty_writeback, }; const struct file_operations def_blk_fops = { diff --git a/fs/buffer.c b/fs/buffer.c index bbb4348f9025..3b44b5525366 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -82,6 +82,40 @@ void unlock_buffer(struct buffer_head *bh) } EXPORT_SYMBOL(unlock_buffer); +/* + * Returns if the page has dirty or writeback buffers. If all the buffers + * are unlocked and clean then the PageDirty information is stale. If + * any of the pages are locked, it is assumed they are locked for IO. + */ +void buffer_check_dirty_writeback(struct page *page, + bool *dirty, bool *writeback) +{ + struct buffer_head *head, *bh; + *dirty = false; + *writeback = false; + + BUG_ON(!PageLocked(page)); + + if (!page_has_buffers(page)) + return; + + if (PageWriteback(page)) + *writeback = true; + + head = page_buffers(page); + bh = head; + do { + if (buffer_locked(bh)) + *writeback = true; + + if (buffer_dirty(bh)) + *dirty = true; + + bh = bh->b_this_page; + } while (bh != head); +} +EXPORT_SYMBOL(buffer_check_dirty_writeback); + /* * Block until a buffer comes unlocked. This doesn't stop it * from becoming locked again - you have to lock it yourself diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index 23c712825640..8e590bdf1e82 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -1984,6 +1984,7 @@ static const struct address_space_operations ext3_ordered_aops = { .direct_IO = ext3_direct_IO, .migratepage = buffer_migrate_page, .is_partially_uptodate = block_is_partially_uptodate, + .is_dirty_writeback = buffer_check_dirty_writeback, .error_remove_page = generic_error_remove_page, }; diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 9cb2e7030d41..ca31306f7b59 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -139,6 +139,9 @@ BUFFER_FNS(Prio, prio) }) #define page_has_buffers(page) PagePrivate(page) +void buffer_check_dirty_writeback(struct page *page, + bool *dirty, bool *writeback); + /* * Declarations */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 3795b0f39b02..7a3b87931fa5 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -380,6 +380,7 @@ struct address_space_operations { int (*launder_page) (struct page *); int (*is_partially_uptodate) (struct page *, read_descriptor_t *, unsigned long); + void (*is_dirty_writeback) (struct page *, bool *, bool *); int (*error_remove_page)(struct address_space *, struct page *); /* swapfile support */ diff --git a/mm/vmscan.c b/mm/vmscan.c index 0ccc95f57c76..44dbbda53ac4 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -761,6 +761,8 @@ static enum page_references page_check_references(struct page *page, static void page_check_dirty_writeback(struct page *page, bool *dirty, bool *writeback) { + struct address_space *mapping; + /* * Anonymous pages are not handled by flushers and must be written * from reclaim context. Do not stall reclaim based on them @@ -774,6 +776,14 @@ static void page_check_dirty_writeback(struct page *page, /* By default assume that the page flags are accurate */ *dirty = PageDirty(page); *writeback = PageWriteback(page); + + /* Verify dirty/writeback state if the filesystem supports it */ + if (!page_has_private(page)) + return; + + mapping = page_mapping(page); + if (mapping && mapping->a_ops->is_dirty_writeback) + mapping->a_ops->is_dirty_writeback(page, dirty, writeback); } /*