On 5/29/22 6:51PM, Dave Chinner wrote:
On Sat, May 28, 2022 at 02:59:31PM -0400, Theodore Ts'o wrote:
+linux-ext4
On Sat, May 28, 2022 at 03:36:39PM +1000, Dave Chinner wrote:
The other filesystem that uses nobh is the standalone ext2
filesystem that nobody uses anymore as the ext4 module provides ext2
functionality for distros these days. Hence there's an argument that
can be made for removing fs/ext2 as well. In which case, the whole
nobh problem goes away by deprecating and removing both the
filesysetms that use that infrastructure in 2 years time....
This got brought up at this past week's ext4 video chat, where Willy
asked Jan (who has been maintaining ext2) whether he would be open to
converting ext2 to use iomap. The answer was yes. So once jfs and
ext2 are converted, we'll be able to nuke the nobh code.
From Willy's comments on the video chat, my understanding is that jfs
was even simpler to convert that ext2, and this allows us to remove
the nobh infrastructure without asking the question about whether it's
time to remove jfs.
I disagree there - if we are changing code that has been unchanged
for a decade or more, there are very few users of that code, and
there's a good chance that data corruption regressions will result
from the changes being proposed, then asking the question "why take
the risk" is very pertinent.
"Just because we can" isn't a good answer. The best code is code we
don't have to write and maintain. If it's a burden to maintain and a
barrier to progress, then we should seriously be considering
removing it, not trying to maintain the fiction that it's a viable
supported production quality filesystem that people can rely on....
I'm onboard to sunsetting jfs. I don't know of anyone that is currently
using it in any serious way. (jfs-discussion group, this is a good time
to chime in if you feel differently.)
On the other hand, because it is not being used in an any
mission-critical way, it may be a good filesystem to do an early
conversion on to see what issues might come up. Unfortunately, I've got
a really busy two months in front of me and won't be much help.
Thanks,
Shaggy
We also need to convert more filesystems to use iomap.
We also need to deprecate and remove more largely unmaintained and
unused filesystems. :)
Well, Dave Kleikamp is still around and sends jfs pull requests from
time to time, and so it's not as unmaintained as, say, fs/adfs,
fs/freevxs, fs/hpfs, fs/minix, and fs/sysv.
Yes, but the changes that have been made over the past decade are
all small and minor - there's been no feature work, no cleanup work,
no attempt to update core infrastructure, etc. There's beeen no
serious attempts to modernise or update the code for a decade...
As regards to minixfs, I'd argue that ext2 is a better reference file
system than minixfs. So..... are we ready to remove minixfs? I could
easily see that some folks might still have sentimental attachment to
minixfs. :-)
AFAIC, yes, minixfs and and those other ones should have been
deprecated long ago....
Cheers,
Dave.
