3.16.52-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Matthew Wilcox <wi...@infradead.org> commit f892760aa66a2d657deaf59538fb69433036767c upstream. 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(). [a...@linux-foundation.org: s/PAGE_SIZE/~0U/ per Linus and Matthew] Link: http://lkml.kernel.org/r/20171006211541.ga7...@bombadil.infradead.org Signed-off-by: Matthew Wilcox <mawil...@microsoft.com> Reported-by: Toshi Kani <toshi.k...@hpe.com> Reported-by: OGAWA Hirofumi <hirof...@mail.parknet.co.jp> Tested-by: Toshi Kani <toshi.k...@hpe.com> Acked-by: Johannes Thumshirn <jthumsh...@suse.de> Cc: Ross Zwisler <ross.zwis...@linux.intel.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <b...@decadent.org.uk> --- fs/block_dev.c | 6 ++++-- fs/mpage.c | 14 +++++++++++--- include/linux/buffer_head.h | 1 + 3 files changed, 16 insertions(+), 5 deletions(-) --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -419,10 +419,12 @@ int bdev_write_page(struct block_device return -EOPNOTSUPP; set_page_writeback(page); result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw); - if (result) + if (result) { end_page_writeback(page); - else + } else { + clean_page_buffers(page); unlock_page(page); + } return result; } EXPORT_SYMBOL_GPL(bdev_write_page); --- a/fs/mpage.c +++ b/fs/mpage.c @@ -457,6 +457,16 @@ static void clean_buffers(struct page *p 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) { @@ -594,10 +604,8 @@ 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_get_nr_vecs(bdev), GFP_NOFS|__GFP_HIGH); --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -222,6 +222,7 @@ int generic_write_end(struct file *, str loff_t, unsigned, unsigned, struct page *, void *); void page_zero_new_buffers(struct page *page, unsigned from, unsigned to); +void clean_page_buffers(struct page *page); int cont_write_begin(struct file *, struct address_space *, loff_t, unsigned, unsigned, struct page **, void **, get_block_t *, loff_t *);
