From: "J. R. Okajima" <hooanon05@yahoo.co.jp>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>,
Miklos Szeredi <miklos@szeredi.hu>,
jack@suse.cz, torvalds@linux-foundation.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
hch@infradead.org, akpm@linux-foundation.org, apw@canonical.com,
nbd@openwrt.org, neilb@suse.de, jordipujolp@gmail.com,
ezk@fsl.cs.sunysb.edu, sedat.dilek@googlemail.com,
mszeredi@suse.cz
Subject: Re: [PATCH 2/9] vfs: export do_splice_direct() to modules
Date: Sat, 23 Mar 2013 11:49:11 +0900 [thread overview]
Message-ID: <23399.1364006951@jrobl> (raw)
In-Reply-To: <20130322182107.GQ21522@ZenIV.linux.org.uk>
Al Viro:
> The scenario, BTW, looks so:
> process A does sb_start_write() (on your upper layer)
> process B tries to freeze said upper layer and blocks, waiting for A to finish
> process C grabs ->i_mutex in your upper layer
> process C does vfs_write(), which blocks, since there's a pending attempt to
> freeze
> process A tries to grab ->i_mutex held by C and blocks
According to latest mm/filemap.c:generic_file_aio_write(),
sb_start_write(inode->i_sb);
mutex_lock(&inode->i_mutex);
ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
mutex_unlock(&inode->i_mutex);
:::
sb_end_write(inode->i_sb);
Process C would block *BEFORE* i_mutex by sb_start_write()? No?
Honestly speaking I didn't pay attention about the freeze feature since
I don't use it. I am making aufs to support it now. But I don't know how
to test it...
J. R. Okajima
next prev parent reply other threads:[~2013-03-23 2:49 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-13 14:16 [PATCH 0/9] overlay filesystem: request for inclusion (v17) Miklos Szeredi
2013-03-13 14:16 ` [PATCH 1/9] vfs: add i_op->dentry_open() Miklos Szeredi
2013-03-13 22:44 ` Andrew Morton
2013-03-14 11:15 ` Miklos Szeredi
2013-03-13 14:16 ` [PATCH 2/9] vfs: export do_splice_direct() to modules Miklos Szeredi
2013-03-13 22:45 ` Andrew Morton
2013-03-17 13:06 ` David Howells
2013-03-18 2:31 ` Dave Chinner
2013-03-18 15:39 ` Jan Kara
2013-03-18 21:53 ` Al Viro
2013-03-18 23:01 ` Al Viro
2013-03-19 1:38 ` Al Viro
2013-03-19 9:00 ` J. R. Okajima
2013-03-19 10:29 ` Miklos Szeredi
2013-03-19 11:04 ` David Howells
2013-03-19 11:40 ` Miklos Szeredi
2013-03-19 17:03 ` Al Viro
2013-03-19 18:32 ` Miklos Szeredi
2013-03-19 21:24 ` Al Viro
2013-03-20 9:15 ` Miklos Szeredi
2013-03-19 20:54 ` Jan Kara
2013-03-19 20:25 ` Jan Kara
2013-03-19 21:38 ` Al Viro
2013-03-19 22:10 ` Al Viro
2013-03-20 2:33 ` Al Viro
2013-03-20 12:30 ` David Howells
2013-03-20 19:52 ` Jan Kara
2013-03-20 21:48 ` Al Viro
2013-03-20 22:19 ` Jan Kara
2013-03-22 17:37 ` J. R. Okajima
2013-03-22 18:11 ` Al Viro
2013-03-22 18:21 ` Al Viro
2013-03-23 2:49 ` J. R. Okajima [this message]
2013-03-23 4:41 ` Al Viro
2013-03-23 5:37 ` J. R. Okajima
2013-03-13 14:16 ` [PATCH 3/9] vfs: export __inode_permission() " Miklos Szeredi
2013-03-13 14:16 ` [PATCH 4/9] vfs: introduce clone_private_mount() Miklos Szeredi
2013-03-13 22:48 ` Andrew Morton
2013-03-14 13:28 ` Miklos Szeredi
2013-03-13 14:16 ` [PATCH 5/9] overlay filesystem Miklos Szeredi
2013-03-13 22:53 ` Andrew Morton
2013-03-13 14:16 ` [PATCH 6/9] overlayfs: add statfs support Miklos Szeredi
2013-03-13 14:16 ` [PATCH 7/9] overlayfs: implement show_options Miklos Szeredi
2013-03-13 14:16 ` [PATCH 8/9] overlay: overlay filesystem documentation Miklos Szeredi
2013-03-13 23:06 ` Andrew Morton
2013-03-14 13:35 ` Miklos Szeredi
2013-03-13 14:16 ` [PATCH 9/9] fs: limit filesystem stacking depth Miklos Szeredi
2013-03-13 14:31 ` [PATCH 0/9] overlay filesystem: request for inclusion (v17) Sedat Dilek
2013-03-13 15:13 ` Sedat Dilek
2013-03-13 15:18 ` Miklos Szeredi
2013-03-13 15:26 ` Sedat Dilek
2013-03-13 15:53 ` Sedat Dilek
2013-03-13 16:10 ` Sedat Dilek
2013-03-13 16:21 ` Miklos Szeredi
2013-03-13 16:35 ` Sedat Dilek
2013-03-13 16:51 ` Sedat Dilek
2013-03-13 18:12 ` Robin Holt
2013-03-13 18:37 ` Felix Fietkau
2013-03-13 19:10 ` Sedat Dilek
2013-03-13 19:54 ` Eric W. Biederman
2013-03-13 19:58 ` Linus Torvalds
2013-03-13 20:27 ` Sedat Dilek
[not found] ` <CAB3woddVfZ9PdYPpzidJLBMmUeRx0Rxgb5Pc8bTM9U-tkcS_uA@mail.gmail.com>
2013-03-13 20:32 ` Sedat Dilek
2013-03-13 20:36 ` Phillip Lougher
2013-03-13 23:08 ` Andrew Morton
2013-03-14 13:43 ` Miklos Szeredi
2013-03-15 1:25 ` Al Viro
2013-03-15 4:15 ` J. R. Okajima
2013-03-15 4:44 ` Al Viro
2013-03-15 5:09 ` J. R. Okajima
2013-03-15 5:13 ` Al Viro
2013-03-15 8:15 ` James Bottomley
2013-03-15 12:12 ` Al Viro
2013-03-15 18:57 ` J. R. Okajima
2013-03-15 19:26 ` Erez Zadok
2013-03-15 20:30 ` Al Viro
2013-03-16 13:55 ` J. R. Okajima
2013-03-15 19:11 ` Linus Torvalds
2013-03-16 13:57 ` J. R. Okajima
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