Date: Tue, 1 Mar 2016 20:03:51 -0500 (EST) From: Rick Macklem <rmacklem@uoguelph.ca> To: "Kenneth D. Merry" <ken@FreeBSD.ORG> Cc: fs@freebsd.org, scsi@freebsd.org Subject: Re: FUSE extended attribute patches available Message-ID: <2079334495.1177596.1456880631768.JavaMail.zimbra@uoguelph.ca> In-Reply-To: <20160301151109.GA79912@mithlond.kdm.org> References: <CD5FCB90-1952-4014-BBE0-1BFF1EF85E17@freebsd.org> <1740288370.14765302.1456790548437.JavaMail.zimbra@uoguelph.ca> <20160301151109.GA79912@mithlond.kdm.org>
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Kenneth D. Merry wrote: > On Mon, Feb 29, 2016 at 19:02:28 -0500, Rick Macklem wrote: > > Ken Merry wrote: > > > I have patches for FreeBSD???s FUSE filesystem kernel module to support > > > extended attributes: > > > > > > https://people.freebsd.org/~ken/fuse_extattr.20160229.1.txt > > > > > > The patch implements the get/set/delete/list extended attribute methods. > > > The > > > listing code also converts extended attribute lists from the Linux/FUSE > > > format to the FreeBSD format. > > I also have patches, although my list didn't work. (I didn't know that > > there was > > a difference between what Linux/FUSE returns vs what FreeBSD wanted. So now > > I know > > why my "list" didn't work.) > > Btw, when I discussed what to do w.r.t. extended attribute namespace, he > > seemed to > > think just considering all the fuse ones as User was ok. > > Ahh. Who is "he" in this context? > rwatson@ > It was easy enough to allow access to the user and system namespace. FUSE > and Linux use the same names, so might as well pass them through. The > other issue as far as FUSE goes, is that it is expecting the "user." or > "system." prefix on the attribute name. > Well, the extended attributes I am interested in are generated automagically by GlusterFS and they don't have a "user." or "system." prefix. For example: glusterfs.gfid This wouldn't work if fuse prepended the "user." or "system.". > FreeBSD passes those as a separate, numeric, argument in the VFS layer at > least, and expects to not see the namespace as a prefix when listing > attributes. > > > I also have patched FreeBSD's Fuse for the other stuff needed to export the > > fuse > > mount via an NFS server. (VFS_FHTOVP() etc) These aren't quite ready for > > "prime time" > > but if anyone wants to try them, just email me and I'll send you a copy. > > > > Btw, I have a couple of patches related to direct I/O and buffered I/O. You > > can > > find 2 of these at PR#206238. I also patched fuse_vnop_inactive() to > > flush/write > > dirty pages. (I think this is needed when an application mmaps a file and > > the > > modifies it after closing the file descriptor. I haven't actually tested to > > see > > if this fix is needed, so I haven't put it anywhere yet.) > > Ahh, cool! Now I can export a tape via NFS! :) > > Seriously, though, that will be helpful for some filesystems. > Btw, I have also done VOP_ADVLOCK(), since GlusterFS supports that. > > > For example: > > > > > > # touch foo > > > # ls -la foo > > > -rwxrwxrwx 1 root wheel 0 Feb 29 21:40 foo > > > # lsextattr user foo > > > foo > > > # setextattr user testattr1 "12345678" foo > > > # lsextattr user foo > > > foo testattr1 > > > # getextattr user testattr1 foo > > > foo 12345678 > > > # setextattr user testattr2 "87654321" foo > > > # lsextattr user foo > > > foo testattr2 testattr1 > > > # rmextattr user testattr1 foo > > > # lsextattr user foo > > > foo testattr2 > > > # getextattr user testattr1 foo > > > getextattr: foo: failed: Attribute not found > > > # getextattr user testattr2 foo > > > foo 87654321 > > > > > > > > > Just to be clear on what this does, it only provides extended attribute > > > support to FreeBSD applications if the underlying FUSE filesystem > > > implements > > > FUSE extended attribute support. Many FUSE filesystems don???t support > > > the > > > extended attribute VFS operations. > > > > > > I have tested this out on IBM???s LTFS implementation, but I have not yet > > > found > > > another FUSE filesystem that supports extended attributes. If anyone > > > knows > > > of one, please let me know so I can try it out. (I looked through a > > > number > > > of the filesystems in sysutils/fusefs* in the ports tree.) > > > > > The FreeBSD GlusterFS port includes a fuse interface that supports extended > > attributes. That is how I tested what I have. (I think the port is now in > > svn, but if not you can find the GlusterFS port at PR#194409.) > > It glusterfs.org doc doesn't mention that you can create/test a volume of > > only one brick, but that works for trivial testing. If you decide to use it > > for testing and have trouble getting it going, just email. I know diddly > > about > > GlusterFS, but I have fired it up a few times. > > Ahh, that would be helpful. I'll give it a try. > > > > Any feedback is welcome. I???m planning to check this into FreeBSD/head > > > in the > > > next week or so. > > > > > I'll try to get around and taking a look to see if there is anything > > different > > than what I did (other than the above "list" case I didn't get right;-). > > Yes, it would be good to get another set of eyes. Perhaps the namespace > handling (user versus system) is different as well. > Yep, as above, the "namespace" is an issue. Have fun with it, rick > Ken > -- > Kenneth Merry > ken@FreeBSD.ORG >
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