Re: Atomic file data replace API
From: Mike Fleetwood <hidden>
Date: 2011-01-07 13:55:07
On 6 January 2011 20:01, Olaf van der Spek [off-list ref] wrote:
Hi, Does btrfs support atomic file data replaces?
Hi Olaf, Yes btrfs does support atomic replace, since kernel 2.6.30 circa June 2009. [1] Special handling was added to ext3, ext4, btrfs (and probably other Linux FSs) for your replace-via-truncate and the alternative replace-via-rename application patterns. Try reading "Delayed allocation and the zero-length file problem" article and comments by Ted Ts'o for further discussion. [2] Mike -- [1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=5a3f23d515a2ebf0c750db80579ca57b28cbce6d [2] http://thunk.org/tytso/blog/2009/03/12/delayed-allocation-and-the-zero-length-file-problem/