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[ Upstream commit 7a243c82ea527cd1da47381ad9cd646844f3b693 ] Unused portion of a part-written fs-block-sized block is not set to zero in unaligned append direct write.This can lead to serious data inconsistencies. Ocfs2 manage disk with cluster size(for example, 1M), part-written in one cluster will change the cluster state from UN-WRITTEN to WRITTEN, VFS(function dio_zero_block) doesn't do the cleaning because bh's state is not set to NEW in function ocfs2_dio_wr_get_block when we write a WRITTEN cluster. For example, the cluster size is 1M, file size is 8k and we direct write from 14k to 15k, then 12k~14k and 15k~16k will contain dirty data. We have to deal with two cases: 1.The starting position of direct write is outside the file. 2.The starting position of direct write is located in the file. We need set bh's state to NEW in the first case. In the second case, we need mapped twice because bh's state of area out file should be set to NEW while area in file not. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/5292e287-8f1a-fd4a-1a14-661e555e0bed@huawei.com Signed-off-by: Jia Guo <guojia12@huawei.com> Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.