Commit f892760a authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Linus Torvalds

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().

[ s/PAGE_SIZE/~0U/ per Linus and Matthew]
Link: default avatarMatthew Wilcox <>
Reported-by: default avatarToshi Kani <>
Reported-by: default avatarOGAWA Hirofumi <>
Tested-by: default avatarToshi Kani <>
Acked-by: default avatarJohannes Thumshirn <>
Cc: Ross Zwisler <>
Cc: <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent e8c97af0
......@@ -716,10 +716,12 @@ int bdev_write_page(struct block_device *bdev, sector_t sector,
result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, true);
if (result)
if (result) {
} else {
return result;
......@@ -468,6 +468,16 @@ static void clean_buffers(struct page *page, unsigned first_unmapped)
* 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 @@ static int __mpage_writepage(struct page *page, struct writeback_control *wbc,
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),
......@@ -232,6 +232,7 @@ int generic_write_end(struct file *, struct address_space *,
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 *);
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