- 22 Jul, 2014 2 commits
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Chuck Lever authored
See RFC 5666 section 3.7: clients don't have to send zero XDR padding. BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=246Signed-off-by:
Chuck Lever <chuck.lever@oracle.com> Signed-off-by:
J. Bruce Fields <bfields@redhat.com>
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Jeff Layton authored
There's a potential race between a lease break and DELEGRETURN call. Suppose a lease break comes in and queues the workqueue job for a delegation, but it doesn't run just yet. Then, a DELEGRETURN comes in finds the delegation and calls destroy_delegation on it to unhash it and put its primary reference. Next, the workqueue job runs and queues the delegation back onto the del_recall_lru list, issues the CB_RECALL and puts the final reference. With that, the final reference to the delegation is put, but it's still on the LRU list. When we go to unhash a delegation, it's because we intend to get rid of it soon afterward, so we don't want lease breaks to mess with it once that occurs. Fix this by bumping the dl_time whenever we unhash a delegation, to ensure that lease breaks don't monkey with it. I believe this is a regression due to commit 02e1215f (nfsd: Avoid taking state_lock while holding inode lock in nfsd_break_one_deleg). Prior to that, the state_lock was held in the lm_break callback itself, and that would have prevented this race. Cc: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by:
Jeff Layton <jlayton@primarydata.com> Signed-off-by:
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- 21 Jul, 2014 3 commits
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Trond Myklebust authored
We will want to add reference counting to the lock stateid and open stateids too in later patches. Signed-off-by:
Trond Myklebust <trond.myklebust@primarydata.com> Reviewed-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Jeff Layton authored
If nfs4_setlease succesfully acquires a new delegation, then another task breaks the delegation before we reach hash_delegation_locked, then the breaking task will see an empty fi_delegations list and do nothing. The client will receive an open reply incorrectly granting a delegation and will never receive a recall. Move more of the delegation fields to be protected by the fi_lock. It's more granular than the state_lock and in later patches we'll want to be able to rely on it in addition to the state_lock. Attempt to acquire a delegation. If that succeeds, take the spinlocks and then check to see if the file has had a conflict show up since then. If it has, then we assume that the lease is no longer valid and that we shouldn't hand out a delegation. There's also one more potential (but very unlikely) problem. If the lease is broken before the delegation is hashed, then it could leak. In the event that the fi_delegations list is empty, reset the fl_break_time to jiffies so that it's cleaned up ASAP by the normal lease handling code. Signed-off-by:
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J. Bruce Fields authored
nfsd4_probe_callback kicks off some work that will eventually run nfsd4_process_cb_update and update the session flags. In theory we could process a following SEQUENCE call before that update happens resulting in flags that don't accurately represent, for example, the lack of a backchannel. Signed-off-by:
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- 18 Jul, 2014 2 commits
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Trond Myklebust authored
Quell another sparse warning. Signed-off-by:
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Chuck Lever authored
The current code always selects XPRT_TRANSPORT_BC_TCP for the back channel, even when the forward channel was not TCP (eg, RDMA). When a 4.1 mount is attempted with RDMA, the server panics in the TCP BC code when trying to send CB_NULL. Instead, construct the transport protocol number from the forward channel transport or'd with XPRT_TRANSPORT_BC. Transports that do not support bi-directional RPC will not have registered a "BC" transport, causing create_backchannel_client() to fail immediately. Fixes: https://bugzilla.linux-nfs.org/show_bug.cgi?id=265Signed-off-by:
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- 17 Jul, 2014 5 commits
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J. Bruce Fields authored
The first 8 ops of the compound are zeroed since they're a part of the argument that's zeroed by the memset(rqstp->rq_argp, 0, procp->pc_argsize); in svc_process_common(). But we handle larger compounds by allocating the memory on the fly in nfsd4_decode_compound(). Other than code recently fixed by 01529e3f "NFSD: Fix memory leak in encoding denied lock", I don't know of any examples of code depending on this initialization. But it definitely seems possible, and I'd rather be safe. Compounds this long are unusual so I'm much more worried about failure in this poorly tested cases than about an insignificant performance hit. Signed-off-by:
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Jeff Layton authored
sparse says: fs/nfsd/auth.c:31:38: warning: incorrect type in argument 1 (different address spaces) fs/nfsd/auth.c:31:38: expected struct cred const *cred fs/nfsd/auth.c:31:38: got struct cred const [noderef] <asn:4>*real_cred Add a new accessor for the ->real_cred and use that to fetch the pointer. Accessing current->real_cred directly is actually quite safe since we know that they can't go away so this is mostly a cosmetic fixup to silence sparse. Signed-off-by: -
Trond Myklebust authored
Add an extra delegation state to allow the stateid to remain in the idr tree until the last reference has been released. This will be necessary to ensure uniqueness once the client_mutex is removed. [jlayton: reset the sc_type under the state_lock in unhash_delegation] Signed-off-by:
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Jeff Layton authored
No need to pass the delegation pointer in here as it's only used to get the nfs4_file pointer. Signed-off-by:
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Jeff Layton authored
state_lock is a heavily contended global lock. We don't want to grab that while simultaneously holding the inode->i_lock. Add a new per-nfs4_file lock that we can use to protect the per-nfs4_file delegation list. Hold that while walking the list in the break_deleg callback and queue the workqueue job for each one. The workqueue job can then take the state_lock and do the list manipulations without the i_lock being held prior to starting the rpc call. Signed-off-by:
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- 16 Jul, 2014 1 commit
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Jeff Layton authored
It's just an obfuscated INIT_WORK call. Just make the work_func_t a non-static symbol and use a normal INIT_WORK call. Signed-off-by:
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- 11 Jul, 2014 11 commits
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Kinglong Mee authored
Note that the caller has already reserved space for count and eof, so xdr->p has already moved past them, only the padding remains. Signed-off-by:
Kinglong Mee <kinglongmee@gmail.com> Fixes dc97618d (nfsd4: separate splice and readv cases) Signed-off-by:
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Kinglong Mee authored
Commit 4ac7249e (nfsd: use get_acl and ->set_acl) don't check the acl returned from get_acl()/posix_acl_from_mode(). Signed-off-by:
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Steve Wise authored
Function send_write() must stop creating sges when it reaches the device max and return the amount sent in the RDMA Write to the caller. Signed-off-by:
Steve Wise <swise@opengridcomputing.com> Signed-off-by:
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Jeff Layton authored
Rename it to better describe what it does, and have it just return the stateid instead of a __be32 (which is now always nfs_ok). Also, do the search for an existing stateid after the delegation check, to reduce cleanup if the delegation check returns error. Signed-off-by:
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Jeff Layton authored
The current enforcement of deny modes is both inefficient and scattered across several places, which makes it hard to guarantee atomicity. The inefficiency is a problem now, and the lack of atomicity will mean races once the client_mutex is removed. First, we address the inefficiency. We have to track deny modes on a per-stateid basis to ensure that open downgrades are sane, but when the server goes to enforce them it has to walk the entire list of stateids and check against each one. Instead of doing that, maintain a per-nfs4_file deny mode. When a file is opened, we simply set any deny bits in that mode that were specified in the OPEN call. We can then use that unified deny mode to do a simple check to see whether there are any conflicts without needing to walk the entire stateid list. The only time we'll need to walk the entire list of stateids is when a stateid that has a deny mode on it is being released, or one is having its deny mode downgraded. In that case, we must walk the entire list and recalculate the fi_share_deny field. Since deny modes are pretty rare today, this should be very rare under normal workloads. To address the potential for races once the client_mutex is removed, protect fi_share_deny with the fi_lock. In nfs4_get_vfs_file, check to make sure that any deny mode we want to apply won't conflict with existing access. If that's ok, then have nfs4_file_get_access check that new access to the file won't conflict with existing deny modes. If that also passes, then get file access references, set the correct access and deny bits in the stateid, and update the fi_share_deny field. If opening the file or truncating it fails, then unwind the whole mess and return the appropriate error. Signed-off-by:
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Jeff Layton authored
Once we remove the client_mutex, there's an unlikely but possible race that could occur. It will be possible for nfs4_file_put_access to race with nfs4_file_get_access. The refcount will go to zero (briefly) and then bumped back to one. If that happens we set ourselves up for a use-after-free and the potential for a lock to race onto the i_flock list as a filp is being torn down. Ensure that we can safely bump the refcount on the file by holding the fi_lock whenever that's done. The only place it currently isn't is in get_lock_access. In order to ensure atomicity with finding the file, use the find_*_file_locked variants and then call get_lock_access to get new access references on the nfs4_file under the same lock. Signed-off-by:
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Jeff Layton authored
Fix the "deny" argument type, and start the loop at 1. The 0 iteration is always a noop. Signed-off-by:
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Jeff Layton authored
Cleanup -- ensure that the stateid bits are set at the same time that the file access refcounts are incremented. Keeping them coherent like this makes it easier to ensure that we account for all of the references. Since the initialization of the st_*_bmap fields is done when it's hashed, we go ahead and hash the stateid before getting access to the file and unhash it if that function returns error. This will be necessary anyway in a follow-on patch that will overhaul deny mode handling. Signed-off-by:
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Jeff Layton authored
We never use anything above bit #3, so an unsigned long for each is wasteful. Shrink them to a char each, and add some WARN_ON_ONCE calls if we try to set or clear bits that would go outside those sizes. Note too that because atomic bitops work on unsigned longs, we have to abandon their use here. That shouldn't be a problem though since we don't really care about the atomicity in this code anyway. Using them was just a convenient way to flip bits. Signed-off-by:
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Jeff Layton authored
...and replace it with a simple swap call. Signed-off-by:
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Jeff Layton authored
Have them take NFS4_SHARE_ACCESS_* flags instead of an open mode. This spares the callers from having to convert it themselves. This also allows us to simplify these functions as we no longer need to do the access_to_omode conversion in either one. Note too that this patch eliminates the WARN_ON in __nfs4_file_get_access. It's valid for now, but in a later patch we'll be bumping the refcounts prior to opening the file in order to close some races, at which point we'll need to remove it anyway. Signed-off-by:
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- 10 Jul, 2014 16 commits
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Trond Myklebust authored
Use filp_close instead of open coding. filp_close does a bit more than just release the locks and put the filp. It also calls ->flush and dnotify_flush, both of which should be done here anyway. Signed-off-by:
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Trond Myklebust authored
Preparation for removal of the client_mutex, which currently protects this array. While we don't actually need the find_*_file_locked variants just yet, a later patch will. So go ahead and add them now to reduce future churn in this code. Signed-off-by:
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Trond Myklebust authored
Access to this list is currently serialized by the client_mutex. Add finer grained locking around this list in preparation for its removal. Signed-off-by:
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Jeff Layton authored
No need to take the lock unless the count goes to 0. Signed-off-by:
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Jeff Layton authored
Bruce says: There's also a preexisting expire_client/laundromat vs break race: - expire_client/laundromat adds a delegation to its local reaplist using the same dl_recall_lru field that a delegation uses to track its position on the recall lru and drops the state lock. - a concurrent break_lease adds the delegation to the lru. - expire/client/laundromat then walks it reaplist and sees the lru head as just another delegation on the list.... Fix this race by checking the dl_time under the state_lock. If we find that it's not 0, then we know that it has already been queued to the LRU list and that we shouldn't queue it again. In the case of destroy_client, we must also ensure that we don't hit similar races by ensuring that we don't move any delegations to the reaplist with a dl_time of 0. Just bump the dl_time by one before we drop the state_lock. We're destroying the delegations anyway, so a 1s difference there won't matter. The fault injection code also requires a bit of surgery here: First, in the case of nfsd_forget_client_delegations, we must prevent the same sort of race vs. the delegation break callback. For that, we just increment the dl_time to ensure that a delegation callback can't race in while we're working on it. We can't do that for nfsd_recall_client_delegations, as we need to have it actually queue the delegation, and that won't happen if we increment the dl_time. The state lock is held over that function, so we don't need to worry about these sorts of races there. There is one other potential bug nfsd_recall_client_delegations though. Entries on the victims list are not dequeued before calling nfsd_break_one_deleg. That's a potential list corruptor, so ensure that we do that there. Reported-by:"J. Bruce Fields" <bfields@fieldses.org> Signed-off-by:
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Kinglong Mee authored
Commit 8c7424cf (nfsd4: don't try to encode conflicting owner if low on space) forgot free conf->data in nfsd4_encode_lockt and before sign conf->data to NULL in nfsd4_encode_lock_denied. Signed-off-by:
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Trond Myklebust authored
lookup_clientid is preferable to find_confirmed_client since it's able to use the cached client in the compound state. Signed-off-by:
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Trond Myklebust authored
In later patches, we'll be moving the stateowner table into the nfs4_client, and by doing this we ensure that we have a cached nfs4_client pointer. Signed-off-by:
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Trond Myklebust authored
...and have alloc_init_open_stateowner just use the cstate->clp pointer instead of passing in a clp separately. This allows us to use the cached nfs4_client pointer in the cstate instead of having to look it up again. Signed-off-by:
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Jeff Layton authored
We want to use the nfsd4_compound_state to cache the nfs4_client in order to optimise away extra lookups of the clid. In the v4.0 case, we use this to ensure that we only have to look up the client at most once per compound for each call into lookup_clientid. For v4.1+ we set the pointer in the cstate during SEQUENCE processing so we should never need to do a search for it. Signed-off-by:
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Jeff Layton authored
I saw this pop up with some pynfs testing: [ 123.609992] nfsd: non-standard errno: -7 ...and -7 is -E2BIG. I think what happened is that XFS returned -E2BIG due to some xattr operations with the ACL10 pynfs TEST (I guess it has limited xattr size?). Add a better mapping for that error since it's possible that we'll need it. How about we convert it to NFSERR_FBIG? As Bruce points out, they both have "BIG" in the name so it must be good. Also, turn the printk in this function into a WARN() so that we can get a bit more information about situations that don't have proper mappings. Signed-off-by: -
Jeff Layton authored
Commit 2a7420c03e504 (nfsd: Ensure that nfsd_create_setattr commits files to stable storage), added a couple of calls to commit_metadata, but doesn't convert their return codes to __be32 in the appropriate places. Cc: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by:
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Trond Myklebust authored
The cstate already holds information about the session, and hence the client id, so it makes more sense to pass that information rather than the current practice of passing a 'minor version' number. Signed-off-by:
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Trond Myklebust authored
If the client were to disappear from underneath us while we're holding a session reference, things would be bad. This cleanup helps ensure that it cannot, which will be a possibility when the client_mutex is removed. Signed-off-by:
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Jeff Layton authored
Now that we know that we won't have several lockowners with the same, owner->data, we can simplify nfsd4_release_lockowner and get rid of the lo_list in the process. Signed-off-by:
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Trond Myklebust authored
Just like open-owners, lock-owners are associated with a name, a clientid and, in the case of minor version 0, a sequence id. There is no association to a file. Signed-off-by:
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