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2009-06-17lockd: Don't bother with RPC ping for NSM upcallsChuck Lever
Cut NSM upcall RPC traffic in half -- don't do a NULL call first. The cases where a ping would be helpful are rare. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-06-17lockd: Update NSM state from SM_MON repliesChuck Lever
When rpc.statd starts up in user space at boot time, it attempts to write the latest NSM local state number into /proc/sys/fs/nfs/nsm_local_state. If lockd.ko isn't loaded yet (as is the case in most configurations), that file doesn't exist, thus the kernel's NSM state remains set to its initial value of zero during lockd operation. This is a problem because rpc.statd and lockd use the NSM state number to prevent repeated lock recovery on rebooted hosts. If lockd sends a zero NSM state, but then a delayed SM_NOTIFY with a real NSM state number is received, there is no way for lockd or rpc.statd to distinguish that stale SM_NOTIFY from an actual reboot. Thus lock recovery could be performed after the rebooted host has already started reclaiming locks, and those locks will be lost. We could change /etc/init.d/nfslock so it always modprobes lockd.ko before starting rpc.statd. However, if lockd.ko is ever unloaded and reloaded, we are back at square one, since the NSM state is not preserved across an unload/reload cycle. This may happen frequently on clients that use automounter. A period of NFS inactivity causes lockd.ko to be unloaded, and the kernel loses its NSM state setting. Instead, let's use the fact that rpc.statd plants the local system's NSM state in every SM_MON (and SM_UNMON) reply. lockd performs a synchronous SM_MON upcall to the local rpc.statd _before_ sending its first NLM request to a new remote. This would permit rpc.statd to provide the current NSM state to lockd, even after lockd.ko had been unloaded and reloaded. Note that NLMPROC_LOCK arguments are constructed before the nsm_monitor() call, so we have to rearrange argument construction very slightly to make this all work out. And, the kernel appears to treat NSM state as a u32 (see struct nlm_args and nsm_res). Make nsm_local_state a u32 as well, to ensure we don't get bogus comparison results. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-06-17NFSv4/NLM: Push file locking BKL dependencies down into the NLM layerTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-05-06lockd: fix list corruption on lockd restartJ. Bruce Fields
If lockd is signalled soon enough after restart then locks_start_grace() will try to re-add an entry to a list and trigger a lock corruption warning. Thanks to Wang Chen for the problem report and diagnosis. WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c() ... list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128). ... Pid: 23062, comm: lockd Tainted: G W 2.6.30-rc2 #3 Call Trace: [<c042d5b5>] warn_slowpath+0x71/0xa0 [<c0422a96>] ? update_curr+0x11d/0x125 [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150 [<c044b270>] ? trace_hardirqs_on+0xb/0xd [<c051c61a>] ? _raw_spin_lock+0x53/0xfa [<c051c89f>] __list_add+0x27/0x5c [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd] [<ef8f34da>] set_grace_period+0x39/0x53 [lockd] [<c06b8921>] ? lock_kernel+0x1c/0x28 [<ef8f3558>] lockd+0x64/0x164 [lockd] [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150 [<c04227b0>] ? complete+0x34/0x3e [<ef8f34f4>] ? lockd+0x0/0x164 [lockd] [<ef8f34f4>] ? lockd+0x0/0x164 [lockd] [<c043dd42>] kthread+0x45/0x6b [<c043dcfd>] ? kthread+0x0/0x6b [<c0403c23>] kernel_thread_helper+0x7/0x10 Reported-by: Wang Chen <wangchen@cn.fujitsu.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: stable@kernel.org
2009-04-06Merge branch 'for-2.6.30' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* 'for-2.6.30' of git://linux-nfs.org/~bfields/linux: (81 commits) nfsd41: define nfsd4_set_statp as noop for !CONFIG_NFSD_V4 nfsd41: define NFSD_DRC_SIZE_SHIFT in set_max_drc nfsd41: Documentation/filesystems/nfs41-server.txt nfsd41: CREATE_EXCLUSIVE4_1 nfsd41: SUPPATTR_EXCLCREAT attribute nfsd41: support for 3-word long attribute bitmask nfsd: dynamically skip encoded fattr bitmap in _nfsd4_verify nfsd41: pass writable attrs mask to nfsd4_decode_fattr nfsd41: provide support for minor version 1 at rpc level nfsd41: control nfsv4.1 svc via /proc/fs/nfsd/versions nfsd41: add OPEN4_SHARE_ACCESS_WANT nfs4_stateid bmap nfsd41: access_valid nfsd41: clientid handling nfsd41: check encode size for sessions maxresponse cached nfsd41: stateid handling nfsd: pass nfsd4_compound_state* to nfs4_preprocess_{state,seq}id_op nfsd41: destroy_session operation nfsd41: non-page DRC for solo sequence responses nfsd41: Add a create session replay cache nfsd41: create_session operation ...
2009-04-01NSM: Fix unaligned accesses in nsm_init_private()Mans Rullgard
This fixes unaligned accesses in nsm_init_private() when creating nlm_reboot keys. Signed-off-by: Mans Rullgard <mans@mansr.com> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-03-28lockd: Start PF_INET6 listener only if IPv6 support is availableChuck Lever
Apparently a lot of people need to disable IPv6 completely on their distributor-built systems, which have CONFIG_IPV6_MODULE enabled at build time. They do this by blacklisting the ipv6.ko module. This causes the creation of the lockd service listener to fail if CONFIG_IPV6_MODULE is set, but the module cannot be loaded. Now that the kernel's PF_INET6 RPC listeners are completely separate from PF_INET listeners, we can always start PF_INET. Then lockd can try to start PF_INET6, but it isn't required to be available. Note this has the added benefit that NLM callbacks from AF_INET6 servers will never come from AF_INET remotes. We no longer have to worry about matching mapped IPv4 addresses to AF_INET when comparing addresses. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-03-28NFS: Revert creation of IPv6 listeners for lockd and NFSv4 callbacksChuck Lever
We're about to convert over to using separate PF_INET and PF_INET6 listeners, instead of a single PF_INET6 listener that also receives AF_INET requests and maps them to AF_INET6. Clear the way by removing the logic in lockd and the NFSv4 callback server that creates an AF_INET6 service listener. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-03-28SUNRPC: Remove @family argument from svc_create() and svc_create_pooled()Chuck Lever
Since an RPC service listener's protocol family is specified now via svc_create_xprt(), it no longer needs to be passed to svc_create() or svc_create_pooled(). Remove that argument from the synopsis of those functions, and remove the sv_family field from the svc_serv struct. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-03-28SUNRPC: Change svc_create_xprt() to take a @family argumentChuck Lever
The sv_family field is going away. Pass a protocol family argument to svc_create_xprt() instead of extracting the family from the passed-in svc_serv struct. Again, as this is a listener socket and not an address, we make this new argument an "int" protocol family, instead of an "sa_family_t." Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-03-18lockd: clean up blocking lock cases of nlsmvc_lock()Miklos Szeredi
No change in behavior, just rearranging the switch so that we break out of the switch if and only if we're in the wait case. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-03-10NLM: Fix GRANT callback address comparison when IPv6 is enabledChuck Lever
The NFS mount command may pass an AF_INET server address to lockd. If lockd happens to be using a PF_INET6 listener, the nlm_cmp_addr() in nlmclnt_grant() will fail to match requests from that host because they will all have a mapped IPv4 AF_INET6 address. Adopt the same solution used in nfs_sockaddr_match_ipaddr() for NFSv4 callbacks: if either address is AF_INET, map it to an AF_INET6 address before doing the comparison. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-02-09lockd: fix regression in lockd's handling of blocked locksJ. Bruce Fields
If a client requests a blocking lock, is denied, then requests it again, then here in nlmsvc_lock() we will call vfs_lock_file() without FL_SLEEP set, because we've already queued a block and don't need the locks code to do it again. But that means vfs_lock_file() will return -EAGAIN instead of FILE_LOCK_DENIED. So we still need to translate that -EAGAIN return into a nlm_lck_blocked error in this case, and put ourselves back on lockd's block list. The bug was introduced by bde74e4bc64415b1 "locks: add special return value for asynchronous locks". Thanks to Frank van Maarseveen for the report; his original test case was essentially for i in `seq 30`; do flock /nfsmount/foo sleep 10 & done Tested-by: Frank van Maarseveen <frankvm@frankvm.com> Reported-by: Frank van Maarseveen <frankvm@frankvm.com> Cc: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-07NLM: Clean up flow of control in make_socks() functionChuck Lever
Clean up: Use Bruce's preferred control flow style in make_socks(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-07NLM: Refactor make_socks() functionChuck Lever
Clean up: extract common logic in NLM's make_socks() function into a helper. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06lockd: Enable NLM use of AF_INET6Chuck Lever
If the kernel is configured to support IPv6 and the RPC server can register services via rpcbindv4, we are all set to enable IPv6 support for lockd. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: Aime Le Rouzic <aime.le-rouzic@bull.net> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Move nsm_create()Chuck Lever
Clean up: one last thing... relocate nsm_create() to eliminate the forward declaration and group it near the only function that actually uses it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Move nsm_use_hostnames to mon.cChuck Lever
Clean up. Treat the nsm_use_hostnames global variable like nsm_local_state. Note that the default value of nsm_use_hostnames is still zero. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Move nsm_addr() to fs/lockd/mon.cChuck Lever
Clean up: nsm_addr_in() is no longer used, and nsm_addr() is used only in fs/lockd/mon.c, so move it there. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Remove include/linux/lockd/sm_inter.hChuck Lever
Clean up: The include/linux/lockd/sm_inter.h header is nearly empty now. Remove it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Replace IP address as our nlm_reboot lookup keyChuck Lever
NLM provides file locking services for NFS files. Part of this service includes a second protocol, known as NSM, which is a reboot notification service. NLM uses this service to determine when to reclaim locks or enter a grace period after a client or server reboots. The NLM service (implemented by lockd in the Linux kernel) contacts the local NSM service (implemented by rpc.statd in Linux user space) via NSM protocol upcalls to register a callback when a particular remote peer reboots. To match the callback to the correct remote peer, the NLM service constructs a cookie that it passes in the request. The NSM service passes that cookie back to the NLM service when it is notified that the given remote peer has indeed rebooted. Currently on Linux, the cookie is the raw 32-bit IPv4 address of the remote peer. To support IPv6 addresses, which are larger, we could use all 16 bytes of the cookie to represent a full IPv6 address, although we still can't represent an IPv6 address with a scope ID in just 16 bytes. Instead, to avoid the need for future changes to support additional address types, we'll use a manufactured value for the cookie, and use that to find the corresponding nsm_handle struct in the kernel during the NLMPROC_SM_NOTIFY callback. This should provide complete support in the kernel's NSM implementation for IPv6 hosts, while remaining backwards compatible with older rpc.statd implementations. Note we also deal with another case where nsm_use_hostnames can change while there are outstanding notifications, possibly resulting in the loss of reboot notifications. After this patch, the priv cookie is always used to lookup rebooted hosts in the kernel. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: More clean up of nsm_get_handle()Chuck Lever
Clean up: refactor nsm_get_handle() so it is organized the same way that nsm_reboot_lookup() is. There is an additional micro-optimization here. This change moves the "hostname & nsm_use_hostnames" test out of the list_for_each_entry() clause in nsm_get_handle(), since it is loop-invariant. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Refactor nsm_handle creation into a helper functionChuck Lever
Clean up. Refactor the creation of nsm_handles into a helper. Fields are initialized in increasing address order to make efficient use of CPU caches. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NLM: Remove "create" argument from nsm_find()Chuck Lever
Clean up: nsm_find() now has only one caller, and that caller unconditionally sets the @create argument. Thus the @create argument is no longer needed. Since nsm_find() now has a more specific purpose, pick a more appropriate name for it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NLM: Call nsm_reboot_lookup() instead of nsm_find()Chuck Lever
Invoke the newly introduced nsm_reboot_lookup() function in nlm_host_rebooted() instead of nsm_find(). This introduces just one behavioral change: debugging messages produced during reboot notification will now appear when the NLMDBG_MONITOR flag is set, but not when the NLMDBG_HOSTCACHE flag is set. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Add nsm_lookup() functionChuck Lever
Introduce a new API to fs/lockd/mon.c that allows nlm_host_rebooted() to lookup up nsm_handles via the contents of an nlm_reboot struct. The new function is equivalent to calling nsm_find() with @create set to zero, but it takes a struct nlm_reboot instead of separate arguments. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NLM: Decode "priv" argument of NLMPROC_SM_NOTIFY as an opaqueChuck Lever
The NLM XDR decoders for the NLMPROC_SM_NOTIFY procedure should treat their "priv" argument truly as an opaque, as defined by the protocol, and let the upper layers figure out what is in it. This will make it easier to modify the contents and interpretation of the "priv" argument, and keep knowledge about what's in "priv" local to fs/lockd/mon.c. For now, the NLM and NSM implementations should behave exactly as they did before. The formation of the address of the rebooted host in nlm_host_rebooted() may look a little strange, but it is the inverse of how nsm_init_private() forms the private cookie. Plus, it's going away soon anyway. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NLM: Change nlm_host_rebooted() to take a single nlm_reboot argumentChuck Lever
Pass the nlm_reboot data structure directly from the NLMPROC_SM_NOTIFY XDR decoders to nlm_host_rebooted(). This eliminates some packing and unpacking of the NLMPROC_SM_NOTIFY results, and prepares for passing these results, including the "priv" cookie, directly to a lookup routine in fs/lockd/mon.c. This patch changes code organization but should not cause any behavioral change. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Encode the new "priv" cookie for NSMPROC_MON requestsChuck Lever
Pass the new "priv" cookie to NSMPROC_MON's XDR encoder, instead of creating the "priv" argument in the encoder at call time. This patch should not cause a behavioral change: the contents of the cookie remain the same for the time being. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Generate NSMPROC_MON's "priv" argument when nsm_handle is createdChuck Lever
Introduce a new data type, used by both the in-kernel NLM and NSM implementations, that is used to manage the opaque "priv" argument for the NSMPROC_MON and NLMPROC_SM_NOTIFY calls. Construct the "priv" cookie when the nsm_handle is created. The nsm_init_private() function may look a little strange, but it is roughly equivalent to how the XDR encoder formed the "priv" argument. It's going to go away soon. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Remove !nsm check from nsm_release()Chuck Lever
The nsm_release() function should never be called with a NULL handle point. If it is, that's a bug. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Remove NULL pointer check from nsm_find()Chuck Lever
The nsm_find() function should never be called with a NULL IP address pointer. If it is, that's a bug. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Add dprintk() calls in nsm_find and nsm_releaseChuck Lever
Introduce some dprintk() calls in fs/lockd/mon.c that are enabled by the NLMDBG_MONITOR flag. These report when we find, create, and release nsm_handles. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Move nsm_find() to fs/lockd/mon.cChuck Lever
The nsm_find() function sets up fresh nsm_handle entries. This is where we will store the "priv" cookie used to lookup nsm_handles during reboot recovery. The cookie will be constructed when nsm_find() creates a new nsm_handle. As much as possible, I would like to keep everything that handles a "priv" cookie in fs/lockd/mon.c so that all the smarts are in one source file. That organization should make it pretty simple to see how all this works. To me, it makes more sense than the current arrangement to keep nsm_find() with nsm_monitor() and nsm_unmonitor(). So, start reorganizing by moving nsm_find() into fs/lockd/mon.c. The nsm_release() function comes along too, since it shares the nsm_lock global variable. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: move to xdr_stream-based XDR encoders and decodersChuck Lever
Introduce xdr_stream-based XDR encoder and decoder functions, which are more careful about preventing RPC buffer overflows. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Move NSM program and procedure numbers to fs/lockd/mon.cChuck Lever
Clean up: Move the RPC program and procedure numbers for NSM into the one source file that needs them: fs/lockd/mon.c. And, as with NLM, NFS, and rpcbind calls, use NSMPROC_FOO instead of SM_FOO for NSM procedure numbers. Finally, make a couple of comments more precise: what is referred to here as SM_NOTIFY is really the NLM (lockd) NLMPROC_SM_NOTIFY downcall, not NSMPROC_NOTIFY. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Move NSM-related XDR data structures to lockd's xdr.hChuck Lever
Clean up: NSM's XDR data structures are used only in fs/lockd/mon.c, so move them there. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Check result of SM_UNMON upcallChuck Lever
Make sure any error returned by rpc.statd during an SM_UNMON call is reported rather than ignored completely. There isn't much to do with such an error, but we should log it in any case. Similar to a recent change to nsm_monitor(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NLM: Move the public declaration of nsm_unmonitor() to lockd.hChuck Lever
Clean up. Make the nlm_host argument "const," and move the public declaration to lockd.h. Add a documenting comment. Bruce observed that nsm_unmonitor()'s only caller doesn't care about its return code, so make nsm_unmonitor() return void. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Release nsmhandle in nlm_destroy_hostChuck Lever
The nsm_handle's reference count is bumped in nlm_lookup_host(). It should be decremented in nlm_destroy_host() to make it easier to see the balance of these two operations. Move the nsm_release() call to fs/lockd/host.c. The h_nsmhandle pointer is set in nlm_lookup_host(), and never cleared. The nlm_destroy_host() function is never called for the same nlm_host twice, so h_nsmhandle won't ever be NULL when nsm_unmonitor() is called. All references to the nlm_host are gone before it is freed. We can skip making h_nsmhandle NULL just before the nlm_host is deallocated. It's also likely we can remove the h_nsmhandle NULL check in nlmsvc_is_client() as well, but we can do that later when rearchitect- ing the nlm_host cache. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NLM: Move the public declaration of nsm_monitor() to lockd.hChuck Lever
Clean up. Make the nlm_host argument "const," and move the public declaration to lockd.h with other NSM public function (nsm_release, eg) and global variable declarations. Add a documenting comment. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Make sure to return an error if the SM_MON call result is not zeroChuck Lever
The nsm_monitor() function reports an error and does not set sm_monitored if the SM_MON upcall reply has a non-zero result code, but nsm_monitor() does not return an error to its caller in this case. Since sm_monitored is not set, the upcall is retried when the next NLM request invokes nsm_monitor(). However, that may not come for a while. In the meantime, at least one NLM request will potentially proceed without the peer being monitored properly. Have nsm_monitor() return an error if the result code is non-zero. This will cause all NLM requests to fail immediately if the upcall completed successfully but rpc.statd returned an error. This may be inconvenient in some cases (for example if rpc.statd cannot complete a proper DNS reverse lookup of the hostname), but will make the reboot monitoring service more robust by forcing such issues to be corrected by an admin. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Remove BUG_ON() in nsm_monitor()Chuck Lever
Clean up: Remove the BUG_ON() invocation in nsm_monitor(). It's not likely that nsm_monitor() is ever called with a NULL host pointer, and the code will die anyway if host is NULL. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NLM: Remove redundant printk() in nlmclnt_lock()Chuck Lever
The nsm_monitor() function already generates a printk(KERN_NOTICE) if the SM_MON upcall fails, so the similar printk() in the nlmclnt_lock() function is redundant. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Use sm_name instead of h_name in nsm_monitor() and nsm_unmonitor()Chuck Lever
Clean up: Use the sm_name field for reporting the hostname in nsm_monitor() and nsm_unmonitor(), just as the other functions in fs/lockd/mon.c do. The h_name field is just a copy of the sm_name pointer. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Support IPv6 version of mon_nameChuck Lever
The "mon_name" argument of the NSMPROC_MON and NSMPROC_UNMON upcalls is a string that contains the hostname or IP address of the remote peer to be notified when this host has rebooted. The sm-notify command uses this identifier to contact the peer when we reboot, so it must be either a well-qualified DNS hostname or a presentation format IP address string. When the "nsm_use_hostnames" sysctl is set to zero, the kernel's NSM provides a presentation format IP address in the "mon_name" argument. Otherwise, the "caller_name" argument from NLM requests is used, which is usually just the DNS hostname of the peer. To support IPv6 addresses for the mon_name argument, we use the nsm_handle's address eye-catcher, which already contains an appropriate presentation format address string. Using the eye-catcher string obviates the need to use a large buffer on the stack to form the presentation address string for the upcall. This patch also addresses a subtle bug. An NSMPROC_MON request and the subsequent NSMPROC_UNMON request for the same peer are required to use the same value for the "mon_name" argument. Otherwise, rpc.statd's NSMPROC_UNMON processing cannot locate the database entry for that peer and remove it. If the setting of nsm_use_hostnames is changed between the time the kernel sends an NSMPROC_MON request and the time it sends the NSMPROC_UNMON request for the same peer, the "mon_name" argument for these two requests may not be the same. This is because the value of "mon_name" is currently chosen at the moment the call is made based on the setting of nsm_use_hostnames To ensure both requests pass identical contents in the "mon_name" argument, we now select which string to use for the argument in the nsm_monitor() function. A pointer to this string is saved in the nsm_handle so it can be used for a subsequent NSMPROC_UNMON upcall. NB: There are other potential problems, such as how nlm_host_rebooted() might behave if nsm_use_hostnames were changed while hosts are still being monitored. This patch does not attempt to address those problems. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: convert printk(KERN_DEBUG) to a dprintk()Chuck Lever
Clean up: make the printk(KERN_DEBUG) in nsm_mon_unmon() a dprintk, and add another dprintk to note if creating an RPC client for the upcall failed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NSM: Use C99 structure initializer to initialize nsm_argsChuck Lever
Clean up: Use a C99 structure initializer instead of open-coding the initialization of nsm_args. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NLM: Add helper to handle IPv4 addressesChuck Lever
Clean up: introduce a helper function to generate IPv4 addresses using the same style as the IPv6 helper function we just added. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-06NLM: Support IPv6 scope IDs in nlm_display_address()Chuck Lever
Scope ID support is needed since the kernel's NSM implementation is about to use these displayed addresses as a mon_name in some cases. When nsm_use_hostnames is zero, without scope ID support NSM will fail to handle peers that contact us via a link-local address. Link-local addresses do not work without an interface ID, which is stored in the sockaddr's sin6_scope_id field. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>