Re: [PATCH 19/60] fs/buffer: comment on direct access to bvec table
From: Christoph Hellwig <hch@infradead.org>
Date: 2016-10-31 15:35:32
Also in:
linux-fsdevel, lkml
I think we'll just need a version zero_fill_bio with a length argument and let that handle all the bvec access. I have vague memories that Kent posted one a while ago, Ccing him. On Sat, Oct 29, 2016 at 04:08:18PM +0800, Ming Lei wrote:
quoted hunk ↗ jump to hunk
Signed-off-by: Ming Lei <tom.leiming@gmail.com> --- fs/buffer.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)diff --git a/fs/buffer.c b/fs/buffer.c index b205a629001d..81c3793948b4 100644 --- a/fs/buffer.c +++ b/fs/buffer.c@@ -3018,8 +3018,13 @@ static void end_bio_bh_io_sync(struct bio *bio) void guard_bio_eod(int op, struct bio *bio) { sector_t maxsector; - struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1]; unsigned truncated_bytes; + /* + * It is safe to truncate the last bvec in the following way + * even though multipage bvec is supported, but we need to + * fix the parameters passed to zero_user(). + */ + struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1]; maxsector = i_size_read(bio->bi_bdev->bd_inode) >> 9; if (!maxsector)-- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
---end quoted text---