On Wed, Nov 16, 2011 at 08:54:45PM +0800, Jan Kara wrote: > On Wed 16-11-11 19:44:21, Wu Fengguang wrote: > > Jan, > > > > Due to the (very low) possibility of data loss by partial writes, IMHO > > it would safer to test this patch in linux-next until next merge window, > > would you agree? > Fine with me. Thanks. Great. The two patches are now in: http://git.kernel.org/?p=linux/kernel/git/wfg/linux.git;a=shortlog;h=refs/heads/writeback-for-next When applying the patch I changed the title "... by a signal" to "... by SIGKILL" to reflect the updated patch content. Hopefully this is also what's in your mind. > > Pushing the first patch will address the main problem, anyway. > Hopefully, yes. I looked over Kazuya's posts in linux-ext4 and think the first patch alone does have good chance address the problem of busy looping in balance_dirty_pages() due to dirty pages never drop under fs error conditions. Thanks, Fengguang > > On Wed, Nov 16, 2011 at 07:12:15PM +0800, Jan Kara wrote: > > > Currently write(2) to a file is not interruptible by a signal. Sometimes this > > > is desirable (e.g. when you want to quickly kill a process hogging your disk or > > > when some process gets blocked in balance_dirty_pages() indefinitely due to a > > > filesystem being in an error condition). > > > > > > Reported-by: Kazuya Mio <k-mio@xxxxxxxxxxxxx> > > > Tested-by: Kazuya Mio <k-mio@xxxxxxxxxxxxx> > > > Signed-off-by: Jan Kara <jack@xxxxxxx> > > > --- > > > mm/filemap.c | 6 ++++-- > > > 1 files changed, 4 insertions(+), 2 deletions(-) > > > > > > diff --git a/mm/filemap.c b/mm/filemap.c > > > index c0018f2..c106d3b 100644 > > > --- a/mm/filemap.c > > > +++ b/mm/filemap.c > > > @@ -2407,7 +2407,6 @@ static ssize_t generic_perform_write(struct file *file, > > > iov_iter_count(i)); > > > > > > again: > > > - > > > /* > > > * Bring in the user page that we will copy from _first_. > > > * Otherwise there's a nasty deadlock on copying from the > > > @@ -2463,7 +2462,10 @@ again: > > > written += copied; > > > > > > balance_dirty_pages_ratelimited(mapping); > > > - > > > + if (fatal_signal_pending(current)) { > > > + status = -EINTR; > > > + break; > > > + } > > > } while (iov_iter_count(i)); > > > > > > return written ? written : status; > > > -- > > > 1.7.1 > -- > Jan Kara <jack@xxxxxxx> > SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
