If the server sends us a target that looks like an outlier, but
is lower than the existing target, then respect it anyway.
However defer actually updating the generation counter until
we get a target that doesn't look like an outlier.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Most (all) NFS4ERR_BADSLOT errors are due to the client failing to
respect the server's sr_highest_slotid limit. This mainly happens
due to reordered RPC requests.
The way to handle it is simply to drop the slot that we're using,
and retry using the new highest_slotid limits.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Jian reported that the following sequence would leave "testfile" with
corrupt data:
# mount localhost:/export /mnt/nfs/ -o vers=3
# echo abc > /mnt/nfs/testfile; echo def >> /export/testfile; echo ghi >> /mnt/nfs/testfile
# cat -v /export/testfile
abc
^@^@^@^@ghi
While there's no locking involved here, the operations are serialized,
so CTO should prevent corruption.
The first write to the file is fine and writes 4 bytes. The file is then
extended on the server. When it's reopened a GETATTR is issued and the
size change is noticed. This causes NFS_INO_INVALID_DATA to be set on
the file. Because the file is opened for write only,
nfs_want_read_modify_write() returns 0 to nfs_write_begin().
nfs_updatepage then calls nfs_write_pageuptodate() to see if it should
extend the nfs_page to cover the whole page. NFS_INO_INVALID_DATA is
still set on the file at that point, but that flag is ignored and
nfs_pageuptodate erroneously extends the write to cover the whole page,
with the write done on the server side filled in with zeroes.
This patch just has that function check for NFS_INO_INVALID_DATA in
addition to NFS_INO_REVAL_PAGECACHE. This fixes the bug, but looking
over the code, I wonder if we might have a similar bug in
nfs_revalidate_size(). The difference between those two flags is very
subtle, so it seems like we ought to be checking for
NFS_INO_INVALID_DATA in most of the places that we look for
NFS_INO_REVAL_PAGECACHE.
I believe this is regression introduced by commit 8d197a568. The code
did check for NFS_INO_INVALID_DATA prior to that patch.
Original bug report is here:
https://bugzilla.redhat.com/show_bug.cgi?id=885743
Cc: <stable@vger.kernel.org> # 3.5+
Reported-by: Jian Li <jiali@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Commit 1f1ea6c "NFSv4: Fix buffer overflow checking in
__nfs4_get_acl_uncached" accidently dropped the checking for too small
result buffer length.
If someone uses getxattr on "system.nfs4_acl" on an NFSv4 mount
supporting ACLs, the ACL has not been cached and the buffer suplied is
too short, we still copy the complete ACL, resulting in kernel and user
space memory corruption.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Cc: stable@kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Look for sudden changes in the first and second derivatives in order
to eliminate outlier changes to target_highest_slotid (which are
due to out-of-order RPC replies).
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, the priority queues attempt to be 'fair' to lower priority
tasks by scheduling them after a certain number of higher priority tasks
have run. The problem is that both the transport send queue and
the NFSv4.1 session slot queue have strong ordering requirements.
This patch therefore removes the fairness code in favour of strong
ordering of task priorities.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, we see a lot of bouncing for the value of highest_used_slotid
due to the fact that slots are getting freed, instead of getting instantly
transmitted to the next waiting task.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We want to preserve the rpc_task priority for things like writebacks,
that may have differing levels of urgency.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
All it does is pass its arguments through to another function. Let's
cut out the middleman...
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Privileged rpc calls are those that are run by the state recovery thread,
in cases where we're trying to recover the system after a server reboot
or a network partition. In those cases, we want to fence off all other
rpc calls (see nfs4_begin_drain_session()) so that they don't end up
using stateids or clientids that are in the process of being recovered.
Prior to this patch, we had to set up special callback functions in
order to declare an rpc call as being privileged.
By adding a new field to the sequence arguments, this patch simplifies
things considerably, and allows us to declare the rpc call as privileged
before it is run.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It is more important to preserve the task priority behaviour, which ensures
that things like reclaim writes take precedence over background and kupdate
writes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We shouldn't need to pass the 'cache_reply' parameter if we
initialise the sequence_args/sequence_res in the caller.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Nobody calls nfs4_setup_sequence or nfs41_setup_sequence without
also calling rpc_call_start() on success. This commit therefore
folds the rpc_call_start call into nfs41_setup_sequence().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
There is no point in using nfs4_setup_sequence or nfs4_sequence_done
in pure NFSv4.1 functions. We already know that those have sessions...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the server requests a lower target_highest_slotid, then ensure
that we ping it with at least one RPC call containing an
appropriate SEQUENCE op. This ensures that the server won't need to
send a recall callback in order to shrink the slot table.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This means that we end up statically allocating 128 bytes for the
bitmap on each slot table.
For a server that supports 1MB write and read I/O sizes this means
that we can completely fill the maximum 1GB TCP send/receive
windows.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
nfs4_wait_clnt_recover and nfs4_client_recover_expired_lease are both
generic state related functions. As such, they belong in nfs4state.c,
and not nfs4proc.c
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Coalesce nfs4_check_drain_bc_complete and nfs4_check_drain_fc_complete
into a single function that can be called when the slot table is known
to be empty, then change nfs4_callback_free_slot() and nfs4_free_slot()
to use it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the NFSv4.1 session slot allocation fails due to an ENOMEM condition,
then set the task->tk_timeout to 1/4 second to ensure that we do retry
the slot allocation more quickly.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
RFC5661 requires us to make sure that the server knows we've updated
our slot table size by sending at least one SEQUENCE op containing the
new 'highest_slotid' value.
We can do so using the 'CHECK_LEASE' functionality of the state
manager.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The state manager no longer needs any special machinery to stop the
session flow and resize the slot table. It is all done on the fly by
the SEQUENCE op code now.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Instead of an array of slots, use a singly linked list of slots that
can be dynamically appended to or shrunk.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Allow the server to control the size of the session slot table
by adjusting the value of sr_target_max_slots in the reply to the
SEQUENCE operation.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the server wants to leave us with only one slot, or it wants
to "shrink" our slot table to something larger than we have now,
then so be it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ensure that the NFSv4.1 CB_RECALL_SLOT callback updates the slot table
target max slotid safely.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When the server tells us that it is dynamically resizing the session
replay cache, we should reset the sequence number for those slots
that have been deallocated.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Dynamic slot allocation in NFSv4.1 depends on the client being able to
track the server's target value for the highest slotid in the
slot table. See the reference in Section 2.10.6.1 of RFC5661.
To avoid ordering problems in the case where 2 SEQUENCE replies contain
conflicting updates to this target value, we also introduce a generation
counter, to track whether or not an RPC containing a SEQUENCE operation
was launched before or after the last update.
Also rename the nfs4_slot_table target_max_slots field to
'target_highest_slotid' to avoid confusion with a slot
table size or number of slots.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Change the argument to take the pointer to the slot, instead of
just the slotid.
We know that the new value of highest_used_slot must be less than
the current value. No need to scan the whole table.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up the NFSv4.1 slot allocation by replacing nfs_find_slot() with
a function nfs_alloc_slot() that returns a pointer to the nfs4_slot
instead of an offset into the slot table.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Instead of doing slot table pointer gymnastics every time we want to
know which slot we're using.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move the session pointer into the slot table, then have struct nfs4_slot
point to that slot table.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The slab cache in nfs_commit_mempool is wrong, and I think it is just a slip.
I tested it on a x86-32 machine, the size of nfs_write_header is 544, and
the size of nfs_commit_data is 408, so it works fine. It is also true that
sizeof(struct nfs_write_header) > sizeof(struct nfs_commit_data) on other
platforms in my opinoin. Just fix it.
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
encode_exchange_id() uses more stack space than necessary, giving a compile
time warning. Reduce the size of the static buffer for implementation name.
Signed-off-by: Jim Rees <rees@umich.edu>
Reviewed-by: "Adamson, Dros" <Weston.Adamson@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We must always bump the clientid sequence number after a successful
call to CREATE_SESSION on the server. The result of
nfs4_verify_channel_attrs() is irrelevant to that requirement.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we're mounting a new filesystem, ensure that the session has negotiated
large enough request and reply sizes to match the wsize and rsize mount
arguments.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Don't store the target request and response sizes in the same
variables used to store the server's replies to those targets.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We can't send a SEQUENCE op unless the session is OK, so it is pointless
to handle the CHECK_LEASE state before we've dealt with SESSION_RESET
and BIND_CONN_TO_SESSION.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If I mount an NFS v4.1 server to a single client multiple times and then
run xfstests over each mountpoint I usually get the client into a state
where recovery deadlocks. The server informs the client of a
cb_path_down sequence error, the client then does a
bind_connection_to_session and checks the status of the lease.
I found that bind_connection_to_session sets the NFS4_SESSION_DRAINING
flag on the client, but this flag is never unset before
nfs4_check_lease() reaches nfs4_proc_sequence(). This causes the client
to deadlock, halting all NFS activity to the server. nfs4_proc_sequence()
is only called by the state manager, so I can change it to run in privileged
mode to bypass the NFS4_SESSION_DRAINING check and avoid the deadlock.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
Trond Myklebust
Jeff Layton
Sven Wegener
Bryan Schumaker
Yanchuan Nian
Jim Rees