Ilya, Regarding supported attribute list, I think it could be a step towards better usability experience during rbd map command. Presently, if user gives wrong option or unsupported option it just errors out saying 'sysfs write failed' or so. User has no idea what went wrong. We can use this supported list from kernel module from rbd cli to show proper error message to the user. Another feature that we have implemented is rbd cli to consult the /etc/ceph/ceph.conf and take the rbd kernel supported options from there automatically if user has not provided any option during rbd map. User provided option during rbd map will always get priority though. Let me know your thought on this. Thanks & Regards Somnath -----Original Message----- From: ceph-devel-owner@xxxxxxxxxxxxxxx [mailto:ceph-devel-owner@xxxxxxxxxxxxxxx] On Behalf Of Ilya Dryomov Sent: Wednesday, January 21, 2015 11:19 AM To: Chaitanya Huilgol Cc: Ceph Development Subject: Re: [PATCH] ceph: rbd option listing and tcp_nodelay support On Wed, Jan 21, 2015 at 10:00 PM, Chaitanya Huilgol <chaitanya.huilgol@xxxxxxxxx> wrote: > From: Chaitanya Huilgol <chaitanya.huilgol@xxxxxxxxxxx> > > Option keys supported by libceph and rbd modules is readable as a > comma separated string via /sys/bus/rbd/options read-only interface. > This will allow user app (rbd cli) to check for supported option keys > before passing options to the kernel and remain compatible with older > kernels which do not support a particular feature. > Messenger specific options moved to messenger layer. > tcp_nodelay(default)/no_tcp_nodelay option added for setting > TCP_NODELAY on messenger socket connections. Covers both rbd and > cephfs Hi Chaitanya, Just couple high level comments - I'll take a closer look tomorrow. Option listing and tcp_nodelay should be two separate patches rbd: add option sysfs attiribute libceph: add tcp_nodelay option or something like that. The "Messenger specific options moved to messenger layer" part should probably be a separate patch as well. More importantly, I'm missing the whole point of exporting supported rbd options. Adding a new libceph option does not break compatibility in either way, as old kernels will simply fail to map/mount if a bad (unknown, let through by new rbd cli) option is encountered. Thanks, Ilya -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html ________________________________ PLEASE NOTE: The information contained in this electronic mail message is intended only for the use of the designated recipient(s) named above. If the reader of this message is not the intended recipient, you are hereby notified that you have received this message in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify the sender by telephone or e-mail (as shown above) immediately and destroy any and all copies of this message in your possession (whether hard copies or electronically stored copies). ��.n��������+%������w��{.n����z��u���ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
