From aaa4059bc2dca7fa816624a28db1958c3a22df9b Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Sun, 30 Oct 2005 15:00:16 -0800 Subject: [PATCH] ext3: Fix unmapped buffers in transaction's lists Fix the problem (BUG 4964) with unmapped buffers in transaction's t_sync_data list. The problem is we need to call filesystem's own invalidatepage() from block_write_full_page(). block_write_full_page() must call filesystem's invalidatepage(). Otherwise following nasty race can happen: proc 1 proc 2 ------ ------ - write some new data to 'offset' => bh gets to the transactions data list - starts truncate => i_size set to new size - mpage_writepages() - ext3_ordered_writepage() to 'offset' - block_write_full_page() - page->index > end_index+1 - block_invalidatepage() - discard_buffer() - clear_buffer_mapped() - commit triggers and finds unmapped buffer - BOOM! Signed-off-by: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/buffer.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index 2066e4cb700c..75cac9ada026 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1637,6 +1637,15 @@ out: } EXPORT_SYMBOL(block_invalidatepage); +int do_invalidatepage(struct page *page, unsigned long offset) +{ + int (*invalidatepage)(struct page *, unsigned long); + invalidatepage = page->mapping->a_ops->invalidatepage; + if (invalidatepage == NULL) + invalidatepage = block_invalidatepage; + return (*invalidatepage)(page, offset); +} + /* * We attach and possibly dirty the buffers atomically wrt * __set_page_dirty_buffers() via private_lock. try_to_free_buffers @@ -2696,7 +2705,7 @@ int block_write_full_page(struct page *page, get_block_t *get_block, * they may have been added in ext3_writepage(). Make them * freeable here, so the page does not leak. */ - block_invalidatepage(page, 0); + do_invalidatepage(page, 0); unlock_page(page); return 0; /* don't care */ } -- cgit v1.2.3