Hi Eric, On 08/16/2011 12:08 AM, Eric Sandeen wrote: > On 8/13/11 11:02 AM, Tao Ma wrote: >> From: Tao Ma <boyu.mt@xxxxxxxxxx> >> >> Hi Michael, >> could you please check whether this patch work for you? > > Thanks, this is the patch I meant to send, I guess ;) I think > I missed the "|=" case before :( > > given that every place we set it requires a test and an increment > if not set, maybe a helper to do all that is in order? I have decided to leave it to the next merge window. So I will re-send this patch as a fix and then create another patch for the helper generalization. Thanks Tao > > -Eric > >> >> Subject: [PATCH] ext4: Set unwritten flag and increase i_aiodio_unwritten simultaneously. >> From 4f1d797973da8b5cf79f58cc1e4d22efb9d46d19 Mon Sep 17 00:00:00 2001 >> From: Tao Ma <boyu.mt@xxxxxxxxxx> >> Date: Sat, 13 Aug 2011 23:50:28 +0800 >> Subject: [PATCH] ext4: Set unwritten flag and increase i_aiodio_unwritten simultaneously. >> >> EXT4_IO_END_UNWRITTEN flag set and the increase of i_aiodio_unwritten should >> be done simultaneously since ext4_end_io_nolock always clear the flag and >> decrease the counter in the same time. >> >> We don't increase i_aiodio_unwritten when setting EXT4_IO_END_UNWRITTEN so >> it will go nagative and causes some process to wait forever. >> >> Part of the patch came from Eric in his e-mail. >> http://marc.info/?l=linux-ext4&m=131316851417460&w=2 >> >> Reported-by: Michael Tokarev<mjt@xxxxxxxxxx> >> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> >> Signed-off-by: Tao Ma <boyu.mt@xxxxxxxxxx> >> --- >> fs/ext4/inode.c | 9 ++++++++- >> fs/ext4/page-io.c | 6 ++++-- >> 2 files changed, 12 insertions(+), 3 deletions(-) >> >> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c >> index d47264c..40c0b10 100644 >> --- a/fs/ext4/inode.c >> +++ b/fs/ext4/inode.c >> @@ -2668,8 +2668,15 @@ static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate) >> goto out; >> } >> >> - io_end->flag = EXT4_IO_END_UNWRITTEN; >> + /* >> + * It may be over-defensive here to check EXT4_IO_END_UNWRITTEN now, >> + * but being more careful is always safe for the future change. >> + */ >> inode = io_end->inode; >> + if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { >> + io_end->flag |= EXT4_IO_END_UNWRITTEN; >> + atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); >> + } >> >> /* Add the io_end to per-inode completed io list*/ >> spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags); >> diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c >> index 430c401..78839af 100644 >> --- a/fs/ext4/page-io.c >> +++ b/fs/ext4/page-io.c >> @@ -334,8 +334,10 @@ submit_and_retry: >> if ((io_end->num_io_pages >= MAX_IO_PAGES) && >> (io_end->pages[io_end->num_io_pages-1] != io_page)) >> goto submit_and_retry; >> - if (buffer_uninit(bh)) >> - io->io_end->flag |= EXT4_IO_END_UNWRITTEN; >> + if (buffer_uninit(bh) && !(io_end->flag & EXT4_IO_END_UNWRITTEN)) { >> + io_end->flag |= EXT4_IO_END_UNWRITTEN; >> + atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); >> + } >> io->io_end->size += bh->b_size; >> io->io_next_block++; >> ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh)); > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
