linux-kernel - Re: [patch 8/8] fs: add i_op->sync

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 7 Jan 2011 14:06:31 -0500
From:	Ted Ts'o <tytso@....edu>
To:	Nick Piggin <npiggin@...nel.dk>
Cc:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [patch 8/8] fs: add i_op->sync_inode

On Sat, Dec 18, 2010 at 12:46:42PM +1100, Nick Piggin wrote:
> --- linux-2.6.orig/Documentation/filesystems/porting	2010-12-18 00:32:44.000000000 +1100
> +++ linux-2.6/Documentation/filesystems/porting	2010-12-18 03:51:40.000000000 +1100
> +--
> +[mandatory]
> +	Inode writeback and syncing has undergone an overhaul.
> +write_inode_now doesn't sync (unless ->write_inode *always* syncs)
> +

Could you perhaps give a bit more detail in the documentation about
what sync_inode() is supposed to do?  I gather that it is supposed to
(based on the flags), do the specified combination of (a) do writeback
for the pages corresponding to the specified range (if INODE_SYNC_DATA
is given), (b) write out the inode if necessary depending on
INODE_SYNC_DATA_METADATA (for fdatasync) and INODE_SYNC_DATA (for
fsync).

When sync_inode() returns, what is guaranteed is that the appropriate
buffer_heads are dirtied (for both the metadata and the data if the
file system is still using the buffer cache for data I/O) and/or the
data has been pushed to the block I/O system, but the sync_inode()
method does not wait force the dirtied buffers out to disk, and it
does not wait for any initiated I/O to complete (either at the block
I/O layer or guaranteeing that the data has hit the platters by
issuing a barrier request).

Do I have that right?  If so, could we please add that to the
documentation, just so it's clear?  Thanks!!

						- Ted
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/