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X-MS-Exchange-CrossTenant-Id: b61c8803-16f3-4c35-9b17-6f65f441df86 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: sPRrznYSG6i1Rqdk4i9OFg/n0X05vToB8L9YARqTUD/X9ADfhWeBXoArjM7Po+3+EWnUNnRyluCpuVghG8llABqGcIPjXz+8tGz+5Nm85Dk= X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO6PR04MB8330 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260706_055715_888236_5C370ECB X-CRM114-Status: GOOD ( 21.46 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Jul 06, 2026 / 18:28, Guixin Liu wrote: > > > 在 2026/7/6 15:59, Daniel Wagner 写道: > > On Mon, Jul 06, 2026 at 11:10:41AM +0800, Guixin Liu wrote: > > > > > > Example output with two registered hosts and an active holder: > > > > > > > > > > > >    $ cat /sys/kernel/debug/nvmet/testnqn/ns1/reservation > > > > > >    enable : 1 > > > > > >    generation : 2 > > > > > >    notify_mask : 0x0 > > > > > >    rtype : write_exclusive > > > > > >    holder : hostid=11111111-1111-1111-1111-111111111111, rkey=0x1111 > > > > > >    registrants: > > > > > >      hostid=11111111-1111-1111-1111-111111111111, rkey=0x1111 > > > > > >      hostid=22222222-2222-2222-2222-222222222222, rkey=0x2222 > > > > > I expect blktests will make use of this interface eventually. The parser > > > > > for this wont be dead simple, sure doable but not simple. If you see a > > > > > way to make a bit simpler I wouldn't mind. > > > > How about this: > > > > > > > > 1. One holer, multi registrants: > > > >   enable=1 > > > >   generation=2 > > > >   notify_mask=0x0 > > > >   rtype=write_exclusive > > > >   holder=11111111-1111-1111-1111-111111111111,0x1111 > > > >   reg=11111111-1111-1111-1111-111111111111,0x1111 > > > >   reg=22222222-2222-2222-2222-222222222222,0x2222 > > > > > > > > 2. No holder, multi registrants: > > > >   enable=1 > > > >   generation=1 > > > >   notify_mask=0x0 > > > >   rtype=none > > > >   holder=none > > > >   reg=11111111-1111-1111-1111-111111111111,0x1111 > > > >   reg=22222222-2222-2222-2222-222222222222,0x2222 > > > > > > > > 3. No registrant: > > > >   enable=1 > > > >   generation=0 > > > >   notify_mask=0x0 > > > >   rtype=none > > > >   holder=none > > > > > > > > 4. Reservation not enabled: > > > >   enable=0 ... > Hi Shin'ichiro: >     Does this work for you? Hi Guixin, yes, I think it is good enough. If this is sysfs, "one value per file" and "array by files in a directory" would be guided, but this is debugfs readonly data. So, it sounds reasonable to put some data structure into a single debufs attribute file. Uevent like key=value format sounds good. It is a bit wacky to use comma to hold both host id and key for a holder and a registrant, but I cannot think of better solution.