From f892760aa66a2d657deaf59538fb69433036767c Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Fri, 13 Oct 2017 15:58:15 -0700 Subject: fs/mpage.c: fix mpage_writepage() for pages with buffers When using FAT on a block device which supports rw_page, we can hit BUG_ON(!PageLocked(page)) in try_to_free_buffers(). This is because we call clean_buffers() after unlocking the page we've written. Introduce a new clean_page_buffers() which cleans all buffers associated with a page and call it from within bdev_write_page(). [akpm@linux-foundation.org: s/PAGE_SIZE/~0U/ per Linus and Matthew] Link: http://lkml.kernel.org/r/20171006211541.GA7409@bombadil.infradead.org Signed-off-by: Matthew Wilcox Reported-by: Toshi Kani Reported-by: OGAWA Hirofumi Tested-by: Toshi Kani Acked-by: Johannes Thumshirn Cc: Ross Zwisler Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/block_dev.c | 6 ++++-- fs/mpage.c | 14 +++++++++++--- 2 files changed, 15 insertions(+), 5 deletions(-) (limited to 'fs') diff --git a/fs/block_dev.c b/fs/block_dev.c index 93d088ffc05c..789f55e851ae 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -716,10 +716,12 @@ int bdev_write_page(struct block_device *bdev, sector_t sector, set_page_writeback(page); result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, true); - if (result) + if (result) { end_page_writeback(page); - else + } else { + clean_page_buffers(page); unlock_page(page); + } blk_queue_exit(bdev->bd_queue); return result; } diff --git a/fs/mpage.c b/fs/mpage.c index 37bb77c1302c..c991faec70b9 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -468,6 +468,16 @@ static void clean_buffers(struct page *page, unsigned first_unmapped) try_to_free_buffers(page); } +/* + * For situations where we want to clean all buffers attached to a page. + * We don't need to calculate how many buffers are attached to the page, + * we just need to specify a number larger than the maximum number of buffers. + */ +void clean_page_buffers(struct page *page) +{ + clean_buffers(page, ~0U); +} + static int __mpage_writepage(struct page *page, struct writeback_control *wbc, void *data) { @@ -605,10 +615,8 @@ alloc_new: if (bio == NULL) { if (first_unmapped == blocks_per_page) { if (!bdev_write_page(bdev, blocks[0] << (blkbits - 9), - page, wbc)) { - clean_buffers(page, first_unmapped); + page, wbc)) goto out; - } } bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9), BIO_MAX_PAGES, GFP_NOFS|__GFP_HIGH); -- cgit