Use a special error value FILE_LOCK_DEFERRED to mean that a locking
operation returned asynchronously. This is returned by
posix_lock_file() for sleeping locks to mean that the lock has been
queued on the block list, and will be woken up when it might become
available and needs to be retried (either fl_lmops->fl_notify() is
called or fl_wait is woken up).
f_op->lock() to mean either the above, or that the filesystem will
call back with fl_lmops->fl_grant() when the result of the locking
operation is known. The filesystem can do this for sleeping as well
as non-sleeping locks.
This is to make sure, that return values of -EAGAIN and -EINPROGRESS by
filesystems are not mistaken to mean an asynchronous locking.
This also makes error handling in fs/locks.c and lockd/svclock.c slightly
cleaner.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: David Teigland <teigland@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix nlm_fopen() to return NLM_FAILED (or NLM_LCK_DENIED_NOLOCKS) instead
of NLM_LCK_DENIED. The latter means the lock request failed because of a
conflicting lock (i.e. a temporary error), which is wrong in this case.
Also fix the client to return ENOLCK instead of EAGAIN if a blocking lock
request returns with NLM_LOCK_DENIED.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: David Teigland <teigland@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-2.6.27' of git://linux-nfs.org/~bfields/linux: (51 commits)
nfsd: nfs4xdr.c do-while is not a compound statement
nfsd: Use C99 initializers in fs/nfsd/nfs4xdr.c
lockd: Pass "struct sockaddr *" to new failover-by-IP function
lockd: get host reference in nlmsvc_create_block() instead of callers
lockd: minor svclock.c style fixes
lockd: eliminate duplicate nlmsvc_lookup_host call from nlmsvc_lock
lockd: eliminate duplicate nlmsvc_lookup_host call from nlmsvc_testlock
lockd: nlm_release_host() checks for NULL, caller needn't
file lock: reorder struct file_lock to save space on 64 bit builds
nfsd: take file and mnt write in nfs4_upgrade_open
nfsd: document open share bit tracking
nfsd: tabulate nfs4 xdr encoding functions
nfsd: dprint operation names
svcrdma: Change WR context get/put to use the kmem cache
svcrdma: Create a kmem cache for the WR contexts
svcrdma: Add flush_scheduled_work to module exit function
svcrdma: Limit ORD based on client's advertised IRD
svcrdma: Remove unused wait q from svcrdma_xprt structure
svcrdma: Remove unneeded spin locks from __svc_rdma_free
svcrdma: Add dma map count and WARN_ON
...
Push it into those callback functions that actually need it.
Note that all the NFS operations use their own locking, so don't need the
BKL. Ditto for the rpcbind client.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
fcntl(F_GETLK) on an nfs client incorrectly returns
the values for the conflicting lock. fl_len value is
always 1.
If the conflicting lock is (0, 4095) the F_GETLK
request for (1024, 10) returns (0, 1), which doesn't
even cover the requested range, and is quite confusing.
The fix is trivial, set fl_end from the fl_end value
recieved from the nfs server.
Signed-off-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Pass a more generic socket address type to nlmsvc_unlock_all_by_ip() to
allow for future support of IPv6. Also provide additional sanity
checking in failover_unlock_ip() when constructing the server's IP
address.
As an added bonus, provide clean kerneldoc comments on related NLM
interfaces which were recently added.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
It may not be obvious (till you look at the definition of
nlm_alloc_call()) that a function like nlmsvc_create_block() should
consume a reference on success or failure, so I find it clearer if it
takes the reference it needs itself.
And both callers already do this immediately before the call anyway.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
nlmsvc_lock calls nlmsvc_lookup_host to find a nlm_host struct. The
callers of this function, however, call nlmsvc_retrieve_args or
nlm4svc_retrieve_args, which also return a nlm_host struct.
Change nlmsvc_lock to take a host arg instead of calling
nlmsvc_lookup_host itself and change the callers to pass a pointer to
the nlm_host they've already found.
Since nlmsvc_testlock() now just uses the caller's reference, we no
longer need to get or release it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
nlmsvc_testlock calls nlmsvc_lookup_host to find a nlm_host struct. The
callers of this functions, however, call nlmsvc_retrieve_args or
nlm4svc_retrieve_args, which also return a nlm_host struct.
Change nlmsvc_testlock to take a host arg instead of calling
nlmsvc_lookup_host itself and change the callers to pass a pointer to
the nlm_host they've already found.
We take a reference to host in the place where nlmsvc_testlock()
previous did a new lookup, so the reference counting is unchanged from
before.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
If lockd_down is called very rapidly after lockd_up returns, then
there is a slim chance that lockd() will never be called. kthread()
will return before calling the function, so we'll end up never
actually calling the cleanup functions for the thread.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The file_lock structure is used both as a heavy-weight representation of
an active lock, with pointers to reference-counted structures, etc., and
as a simple container for parameters that describe a file lock.
The conflicting lock returned from __posix_lock_file is an example of
the latter; so don't call the filesystem or lock manager callbacks when
copying to it. This also saves the need for an unnecessary
locks_init_lock in the nfsv4 server.
Thanks to Trond for pointing out the error.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Add /proc/fs/nfsd/unlock_filesystem, which allows e.g.:
shell> echo /mnt/sfs1 > /proc/fs/nfsd/unlock_filesystem
so that a filesystem can be unmounted before allowing a peer nfsd to
take over nfs service for the filesystem.
Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Cc: Lon Hohberger <lhh@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
fs/lockd/svcsubs.c | 66 +++++++++++++++++++++++++++++++++++++++-----
fs/nfsd/nfsctl.c | 65 +++++++++++++++++++++++++++++++++++++++++++
include/linux/lockd/lockd.h | 7 ++++
3 files changed, 131 insertions(+), 7 deletions(-)
For high-availability NFS service, we generally need to be able to drop
file locks held on the exported filesystem before moving clients to a
new server. Currently the only way to do that is by shutting down lockd
entirely, which is often undesireable (for example, if you want to
continue exporting other filesystems).
This patch allows the administrator to release all locks held by clients
accessing the client through a given server ip address, by echoing that
address to a new file, /proc/fs/nfsd/unlock_ip, as in:
shell> echo 10.1.1.2 > /proc/fs/nfsd/unlock_ip
The expected sequence of events can be:
1. Tear down the IP address
2. Unexport the path
3. Write IP to /proc/fs/nfsd/unlock_ip to unlock files
4. Signal peer to begin take-over.
For now we only support IPv4 addresses and NFSv2/v3 (NFSv4 locks are not
affected).
Also, if unmounting the filesystem is required, we assume at step 3 that
clients using the given server ip are the only clients holding locks on
the given filesystem; otherwise, an additional patch is required to
allow revoking all locks held by lockd on a given filesystem.
Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Cc: Lon Hohberger <lhh@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
fs/lockd/svcsubs.c | 66 +++++++++++++++++++++++++++++++++++++++-----
fs/nfsd/nfsctl.c | 65 +++++++++++++++++++++++++++++++++++++++++++
include/linux/lockd/lockd.h | 7 ++++
3 files changed, 131 insertions(+), 7 deletions(-)
* git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (80 commits)
SUNRPC: Invalidate the RPCSEC_GSS session if the server dropped the request
make nfs_automount_list static
NFS: remove duplicate flags assignment from nfs_validate_mount_data
NFS - fix potential NULL pointer dereference v2
SUNRPC: Don't change the RPCSEC_GSS context on a credential that is in use
SUNRPC: Fix a race in gss_refresh_upcall()
SUNRPC: Don't disconnect more than once if retransmitting NFSv4 requests
SUNRPC: Remove the unused export of xprt_force_disconnect
SUNRPC: remove XS_SENDMSG_RETRY
SUNRPC: Protect creds against early garbage collection
NFSv4: Attempt to use machine credentials in SETCLIENTID calls
NFSv4: Reintroduce machine creds
NFSv4: Don't use cred->cr_ops->cr_name in nfs4_proc_setclientid()
nfs: fix printout of multiword bitfields
nfs: return negative error value from nfs{,4}_stat_to_errno
NLM/lockd: Ensure client locking calls use correct credentials
NFS: Remove the buggy lock-if-signalled case from do_setlk()
NLM/lockd: Fix a race when cancelling a blocking lock
NLM/lockd: Ensure that nlmclnt_cancel() returns results of the CANCEL call
NLM: Remove the signal masking in nlmclnt_proc/nlmclnt_cancel
...
When svc_recv returns an unexpected error, lockd will print a warning
and exit. This problematic for several reasons. In particular, it will
cause the reference counts for the thread to be wrong, and can lead to a
potential BUG() call.
Rather than exiting on error from svc_recv, have the thread do a 1s
sleep and then retry the loop. This is unlikely to cause any harm, and
if the error turns out to be something temporary then it may be able to
recover.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
As of 5996a298da ("NLM: don't unlock on
cancel requests") we no longer unlock in this case, so the comment is no
longer accurate.
Thanks to Stuart Friedberg for pointing out the inconsistency.
Cc: Stuart Friedberg <sfriedberg@hp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
There's no reason for a mutex here, except to allow an allocation under
the lock, which we can avoid with the usual trick of preallocating
memory for the new object and freeing it if it turns out to be
unnecessary.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Use list_for_each_entry(). Also, in keeping with kernel style, make the
normal case (kzalloc succeeds) unindented and handle the abnormal case
with a goto.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The sm_count is decremented to zero but left on the nsm_handles list.
So in the space between decrementing sm_count and acquiring nsm_mutex,
it is possible for another task to find this nsm_handle, increment the
use count and then enter nsm_release itself.
Thus there's nothing to prevent the nsm being freed before we acquire
nsm_mutex here.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Have lockd_up start lockd using kthread_run. With this change,
lockd_down now blocks until lockd actually exits, so there's no longer
need for the waitqueue code at the end of lockd_down. This also means
that only one lockd can be running at a time which simplifies the code
within lockd's main loop.
This also adds a check for kthread_should_stop in the main loop of
nlmsvc_retry_blocked and after that function returns. There's no sense
continuing to retry blocks if lockd is coming down anyway.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Lockd caches information about hosts that have recently held locks to
expedite the taking of further locks.
It periodically discards this information for hosts that have not been
used for a few minutes.
lockd currently has a value NLM_HOST_MAX, and changes the 'garbage
collection' behaviour when the number of hosts exceeds this threshold.
However its behaviour is strange, and likely not what was intended.
When the number of hosts exceeds the max, it scans *less* often (every
2 minutes vs every minute) and allows unused host information to
remain around longer (5 minutes instead of 2).
Having this limit is of dubious value anyway, and we have not
suffered from the code not getting the limit right, so remove the
limit altogether. We go with the larger values (discard 5 minute old
hosts every 2 minutes) as they are probably safer.
Maybe the periodic garbage collection should be replace to with
'shrinker' handler so we just respond to memory pressure....
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
