From 56d35a4cd13e7bc5eca5b2dba5a41794afb17e11 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 5 Aug 2010 14:41:42 -0400 Subject: ext4: Fix dirtying of journalled buffers in data=journal mode In data=journal mode, we still use block_write_begin() to prepare page for writing. This function can occasionally mark buffer dirty which violates journalling assumptions - when a buffer is part of a transaction, it should be dirty and a buffer can be already part of a forget list of some transaction when block_write_begin() gets called. This violation of journalling assumptions then results in "JBD: Spotted dirty metadata buffer..." warnings. In fact, temporary dirtying the buffer while the page is still locked does not really cause problems to the journalling because we won't write the buffer until the page gets unlocked. So we just have to make sure to clear dirty bits before unlocking the page. Signed-off-by: Jan Kara --- fs/ext4/inode.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index ab2247d642c6..a0ab3754d0d6 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1527,9 +1527,25 @@ static int walk_page_buffers(handle_t *handle, static int do_journal_get_write_access(handle_t *handle, struct buffer_head *bh) { + int dirty = buffer_dirty(bh); + int ret; + if (!buffer_mapped(bh) || buffer_freed(bh)) return 0; - return ext4_journal_get_write_access(handle, bh); + /* + * __block_prepare_write() could have dirtied some buffers. Clean + * the dirty bit as jbd2_journal_get_write_access() could complain + * otherwise about fs integrity issues. Setting of the dirty bit + * by __block_prepare_write() isn't a real problem here as we clear + * the bit before releasing a page lock and thus writeback cannot + * ever write the buffer. + */ + if (dirty) + clear_buffer_dirty(bh); + ret = ext4_journal_get_write_access(handle, bh); + if (!ret && dirty) + ret = ext4_handle_dirty_metadata(handle, NULL, bh); + return ret; } /* -- cgit v1.2.3