On 04/24/2013 08:21 PM, Jan Kara wrote: > On Tue 23-04-13 16:37:43, Gu Zheng wrote: >> From 35947e6535d92c54cf523470cc8811e8b5fee3e5 Mon Sep 17 00:00:00 2001 >> From: Gu Zheng <guz.fnst@xxxxxxxxxxxxxx> >> Date: Tue, 23 Apr 2013 16:09:04 +0800 >> Subject: [PATCH] mm/filemap.c: fix criteria of calling iov_shorten() in generic_file_direct_write() >> >> generic_file_direct_write() compares 'count'(the max count we actually can write) >> with 'ocount'(the count we request to write) to see if there is need to call >> iov_shorten() to reduce number of segments and the iovec's length. If the >> 'count' is equal or greater than 'ocount', there is no need to call iov_shorten() >> indeed. So the judgement should be changed: >> 'if (count != ocount)' --> 'if (count < ocount)' > Thanks for the patch but it shouldn't be really possible that count > > ocount, should it? So your patch doesn't really fix anything. Or am I > missing something? Hi Jan, You are right, 'count' should not be greater than 'ocount' actually. Please ignore this patch. Thanks, Gu > > Honza >> >> Signed-off-by: Gu Zheng <guz.fnst@xxxxxxxxxxxxxx> >> --- >> mm/filemap.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/mm/filemap.c b/mm/filemap.c >> index e1979fd..c566b9c 100644 >> --- a/mm/filemap.c >> +++ b/mm/filemap.c >> @@ -2183,7 +2183,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, >> size_t write_len; >> pgoff_t end; >> >> - if (count != ocount) >> + if (count < ocount) >> *nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count); >> >> write_len = iov_length(iov, *nr_segs); >> -- >> 1.7.7 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>