| Message ID | 1561042275-12723-1-git-send-email-bfields@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | exposing knfsd client state to userspace | expand |
On Thu, Jun 20, 2019 at 10:50:59AM -0400, J. Bruce Fields wrote: > - this duplicates some functionality of the little-used fault > injection code; could we replace it entirely? I'd be really curious to hear from any users of that code, by the way. Anna, any ideas? The idea was that it could be used to test client handling of exceptional conditions like recalled delegations and partially lost state. Is anyone regularly running such tests? I don't hate the code, and I'm not on a crusade to tear it all out Right Now, but it does create a few odd corner cases, so I'm wondering whether I could get away with replacing it eventually or whether that risks breaking someone's scripts. --b.
On Fri, 2019-06-21 at 14:13 -0400, J. Bruce Fields wrote: > On Thu, Jun 20, 2019 at 10:50:59AM -0400, J. Bruce Fields wrote: > > - this duplicates some functionality of the little-used fault > > injection code; could we replace it entirely? > > I'd be really curious to hear from any users of that code, by the > way. > Anna, any ideas? I'm not sure who else has used it besides me, and it's been a while since I have too. > > The idea was that it could be used to test client handling of > exceptional conditions like recalled delegations and partially lost > state. Is anyone regularly running such tests? > > I don't hate the code, and I'm not on a crusade to tear it all out > Right > Now, but it does create a few odd corner cases, so I'm wondering > whether > I could get away with replacing it eventually or whether that risks > breaking someone's scripts. I'm cool with replacing it if there is a better way to do things. Anna > > --b.
On Fri, Jun 21, 2019 at 03:25:04PM -0400, Anna Schumaker wrote: > On Fri, 2019-06-21 at 14:13 -0400, J. Bruce Fields wrote: > > On Thu, Jun 20, 2019 at 10:50:59AM -0400, J. Bruce Fields wrote: > > > - this duplicates some functionality of the little-used fault > > > injection code; could we replace it entirely? > > > > I'd be really curious to hear from any users of that code, by the > > way. > > Anna, any ideas? > > I'm not sure who else has used it besides me, and it's been a while > since I have too. Do you remember which ones were most useful? They are: - forget_clients - forget_locks - forget_openowners - forget_delegations - recall_delegations We've got a functional replacement for forget_clients, but I haven't looked into the others yet. --b. > > > > > The idea was that it could be used to test client handling of > > exceptional conditions like recalled delegations and partially lost > > state. Is anyone regularly running such tests? > > > > I don't hate the code, and I'm not on a crusade to tear it all out > > Right > > Now, but it does create a few odd corner cases, so I'm wondering > > whether > > I could get away with replacing it eventually or whether that risks > > breaking someone's scripts. > > I'm cool with replacing it if there is a better way to do things. > > Anna > > > > > --b.
From: "J. Bruce Fields" <bfields@redhat.com> Changes since last time: - added display of client implementation ID - changed display of binary data to escape anything nonprintable or nonascii - some minor cleanup and patch reshuffling I'm happy enough with at this point and hoping to merge it for 5.3. Recapping discussion from last time: The following patches expose information about NFSv4 state held by knfsd on behalf of NFSv4 clients. This is especially important for opens, which are currently invisible to userspace on the server, unlike locks (/proc/locks) and local processes' opens (under /proc/<pid>/). The approach is to add a new directory /proc/fs/nfsd/clients/ with subdirectories for each active NFSv4 client. Each subdirectory has an "info" file with some basic information to help identify the client and a "states" directory that lists the open state held by that client. Currently these pseudofiles look like: # find /proc/fs/nfsd/clients -type f|xargs tail ==> /proc/fs/nfsd/clients/3/ctl <== tail: error reading '/proc/fs/nfsd/clients/3/ctl': Invalid argument ==> /proc/fs/nfsd/clients/3/states <== - 0x01000000f58f0b5d2898a19801000000: { type: open, access: r-, deny: --, superblock: "fd:10:13649", owner: "open id:\x00\x00\x00&\x00\x00\x00\x00\x00\x00\x02x\xac\xd0 \x09" } - 0x01000000f58f0b5d2898a19802000000: { type: deleg, access: r, superblock: "fd:10:13649" } - 0x01000000f58f0b5d2898a19803000000: { type: open, access: r-, deny: --, superblock: "fd:10:13650", owner: "open id:\x00\x00\x00&\x00\x00\x00\x00\x00\x00\x02x\xac\xd0 \x09" } - 0x01000000f58f0b5d2898a19804000000: { type: deleg, access: r, superblock: "fd:10:13650" } ==> /proc/fs/nfsd/clients/3/info <== clientid: 0x98a198285d0b8ff5 address: "192.168.122.36:935" name: "Linux NFSv4.2 test2.fieldses.org" minor version: 2 Implementation domain: "kernel.org" Implementation name: "Linux 5.2.0-rc1-00017-ge73cab140ec0 #2263 SMP PREEMPT Tue Jun 18 16:54:41 EDT 2019 x86_64" Implementation time: [0, 0] The "ctl" file is not readable; all you can do is write "expire\n" to it to force the server to revoke all that client's state. The "info" and "states" files are meant to be valid YAML. Possibly also todo, though I think none have to be done before merging: - add some information about krb5 principals to the clients file. - add information about the stateids used to represent asynchronous copies. They're a little different from the other stateids and might end up in a separate "copies" file, - this duplicates some functionality of the little-used fault injection code; could we replace it entirely? - some of the bits of filesystem code could probably be shared with rpc_pipefs and libfs. --b. J. Bruce Fields (16): nfsd: persist nfsd filesystem across mounts nfsd: rename cl_refcount nfsd4: use reference count to free client nfsd: add nfsd/clients directory nfsd: make client/ directory names small ints nfsd4: add a client info file nfsd: copy client's address including port number to cl_addr nfsd: escape high characters in binary data nfsd: add more information to client info file nfsd4: add file to display list of client's opens nfsd: show lock and deleg stateids nfsd4: show layout stateids nfsd: create get_nfsdfs_clp helper nfsd: allow forced expiration of NFSv4 clients nfsd: create xdr_netobj_dup helper nfsd: decode implementation id fs/nfsd/netns.h | 6 + fs/nfsd/nfs4state.c | 453 ++++++++++++++++++++++++++++++--- fs/nfsd/nfs4xdr.c | 21 +- fs/nfsd/nfsctl.c | 221 +++++++++++++++- fs/nfsd/nfsd.h | 11 + fs/nfsd/state.h | 11 +- fs/nfsd/xdr4.h | 3 + fs/seq_file.c | 11 + include/linux/seq_file.h | 1 + include/linux/string_helpers.h | 3 + include/linux/sunrpc/xdr.h | 7 + lib/string_helpers.c | 19 ++ 12 files changed, 723 insertions(+), 44 deletions(-)