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 <mawilcox@microsoft.com>
Reported-by: Toshi Kani <toshi.kani@hpe.com>
Reported-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Tested-by: Toshi Kani <toshi.kani@hpe.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/mpage.c b/fs/mpage.c
index 37bb77c..c991fae 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -468,6 +468,16 @@
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 @@
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);