From: Jan Kara <jack@suse.cz>
To: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,
linux-btrfs@vger.kernel.org, hch@infradead.org,
andres@anarazel.de, david@fromorbit.com, riteshh@linux.ibm.com,
linux-f2fs-devel@lists.sourceforge.net, Ted Tso <tytso@mit.edu>,
Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: Re: [PATCH 2/3] ext4: fix inode rwsem regression
Date: Mon, 23 Sep 2019 12:10:42 +0200 [thread overview]
Message-ID: <20190923101042.GA25332@quack2.suse.cz> (raw)
In-Reply-To: <20190911164517.16130-3-rgoldwyn@suse.de>
On Wed 11-09-19 11:45:16, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
>
> This is similar to 942491c9e6d6 ("xfs: fix AIM7 regression")
> Apparently our current rwsem code doesn't like doing the trylock, then
> lock for real scheme. So change our read/write methods to just do the
> trylock for the RWF_NOWAIT case.
>
> Fixes: 728fbc0e10b7 ("ext4: nowait aio support")
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Thanks for fixing this! The patch looks good to me. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>
BTW, I've also added Ted as ext4 maintainer to CC.
Honza
> ---
> fs/ext4/file.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index 70b0438dbc94..d5b2d0cc325d 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -40,11 +40,13 @@ static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
> struct inode *inode = file_inode(iocb->ki_filp);
> ssize_t ret;
>
> - if (!inode_trylock_shared(inode)) {
> - if (iocb->ki_flags & IOCB_NOWAIT)
> + if (iocb->ki_flags & IOCB_NOWAIT) {
> + if (!inode_trylock_shared(inode))
> return -EAGAIN;
> + } else {
> inode_lock_shared(inode);
> }
> +
> /*
> * Recheck under inode lock - at this point we are sure it cannot
> * change anymore
> @@ -190,11 +192,13 @@ ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
> struct inode *inode = file_inode(iocb->ki_filp);
> ssize_t ret;
>
> - if (!inode_trylock(inode)) {
> - if (iocb->ki_flags & IOCB_NOWAIT)
> + if (iocb->ki_flags & IOCB_NOWAIT) {
> + if (!inode_trylock(inode))
> return -EAGAIN;
> + } else {
> inode_lock(inode);
> }
> +
> ret = ext4_write_checks(iocb, from);
> if (ret <= 0)
> goto out;
> @@ -233,9 +237,10 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
> if (!o_direct && (iocb->ki_flags & IOCB_NOWAIT))
> return -EOPNOTSUPP;
>
> - if (!inode_trylock(inode)) {
> - if (iocb->ki_flags & IOCB_NOWAIT)
> + if (iocb->ki_flags & IOCB_NOWAIT) {
> + if (!inode_trylock(inode))
> return -EAGAIN;
> + } else {
> inode_lock(inode);
> }
>
> --
> 2.16.4
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2019-09-23 10:10 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190910223327.mnegfoggopwqqy33@alap3.anarazel.de>
[not found] ` <20190911040420.GB27547@dread.disaster.area>
2019-09-11 9:39 ` Odd locking pattern introduced as part of "nowait aio support" Andres Freund
2019-09-11 10:19 ` Christoph Hellwig
2019-09-11 10:31 ` Ritesh Harjani
2019-09-11 10:55 ` Goldwyn Rodrigues
2019-09-11 16:45 ` Fix inode sem regression for nowait Goldwyn Rodrigues
2019-09-11 16:45 ` [PATCH 1/3] btrfs: fix inode rwsem regression Goldwyn Rodrigues
2019-09-11 17:21 ` David Sterba
2019-09-11 16:45 ` [PATCH 2/3] ext4: " Goldwyn Rodrigues
2019-09-12 8:52 ` Ritesh Harjani
2019-09-12 9:26 ` Matthew Bobrowski
2019-09-23 10:10 ` Jan Kara [this message]
2019-09-23 13:18 ` Theodore Y. Ts'o
2019-09-11 16:45 ` [PATCH 3/3] f2fs: " Goldwyn Rodrigues
2019-09-12 6:17 ` Chao Yu
2019-09-13 19:46 ` Jaegeuk Kim
2019-09-16 1:16 ` Chao Yu
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