Commit graph

670 commits

Author SHA1 Message Date
Trond Myklebust 2dc03b7f00 NFSv4.1: Simplify slot allocation
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>
2012-11-26 17:49:52 -05:00
Trond Myklebust 2b2fa71723 NFSv4.1: Simplify struct nfs4_sequence_args too
Replace the session pointer + slotid with a pointer to the
allocated slot.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-26 17:49:52 -05:00
Trond Myklebust df2fabffba NFSv4.1: Label each entry in the session slot tables with its slot number
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>
2012-11-26 17:49:51 -05:00
Trond Myklebust e3725ec015 NFSv4.1: Shrink struct nfs4_sequence_res by moving the session pointer
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>
2012-11-26 17:49:04 -05:00
Trond Myklebust 933602e368 NFSv4.1: Shrink struct nfs4_sequence_res by moving sr_renewal_time
Store the renewal time inside the session slot instead.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-21 09:29:53 -05:00
Trond Myklebust 9216106a84 NFSv4.1: clean up nfs4_recall_slot to use nfs4_alloc_slots
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-21 09:29:53 -05:00
Trond Myklebust 2d473d378e NFSv4.1: nfs4_alloc_slots doesn't need zeroing
All that memory is going to be initialised to non-zero by
nfs4_add_and_init_slots anyway.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-21 09:29:52 -05:00
Trond Myklebust 43095d3972 NFSv4.1: We must bump the clientid sequence number after CREATE_SESSION
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>
2012-11-21 09:29:52 -05:00
Trond Myklebust 688a9024e2 NFSv4.1: Adjust CREATE_SESSION arguments when mounting a new filesystem
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>
2012-11-21 09:29:51 -05:00
Trond Myklebust ae72ae6760 NFSv4.1: Don't confuse CREATE_SESSION arguments and results
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>
2012-11-21 09:29:51 -05:00
Bryan Schumaker 6bdb5f213c NFS: Add sequence_priviliged_ops for nfs4_proc_sequence()
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
2012-11-20 23:34:54 -05:00
Trond Myklebust 4ea8fed593 NFSv4: Get rid of unnecessary BUG_ON()s
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-04 14:43:39 -05:00
Trond Myklebust d3edcf9614 NFSv4: Remove the BUG_ON() from nfs4_get_lease_time_prepare()...
An EAGAIN return value would be unexpected, but there is no reason to
BUG...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-04 14:43:38 -05:00
Weston Andros Adamson 998f40b550 NFS4: nfs4_opendata_access should return errno
Return errno - not an NFS4ERR_. This worked because NFS4ERR_ACCESS == EACCES.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-02 18:51:54 -04:00
Trond Myklebust f9b1ef5f06 NFSv4: Initialise the NFSv4.1 slot table highest_used_slotid correctly
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-01 12:02:03 -04:00
Weston Andros Adamson 324d003b0c NFS: add nfs_sb_deactive_async to avoid deadlock
Use nfs_sb_deactive_async instead of nfs_sb_deactive when in a workqueue
context.  This avoids a deadlock where rpc_shutdown_client loops forever
in a workqueue kworker context, trying to kill all RPC tasks associated with
the client, while one or more of these tasks have already been assigned to the
same kworker (and will never run rpc_exit_task).

This approach is needed because RPC tasks that have already been assigned
to a kworker by queue_work cannot be canceled, as explained in the comment
for workqueue.c:insert_wq_barrier.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
[Trond: add module_get/put.]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-31 16:26:26 -04:00
Trond Myklebust 2b1bc308f4 NFSv4: nfs4_locku_done must release the sequence id
If the state recovery machinery is triggered by the call to
nfs4_async_handle_error() then we can deadlock.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
2012-10-31 15:10:04 -04:00
Trond Myklebust 2240a9e2d0 NFSv4.1: We must release the sequence id when we fail to get a session slot
If we do not release the sequence id in cases where we fail to get a
session slot, then we can deadlock if we hit a recovery scenario.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
2012-10-31 15:08:18 -04:00
Bryan Schumaker 399f11c3d8 NFS: Wait for session recovery to finish before returning
Currently, we will schedule session recovery and then return to the
caller of nfs4_handle_exception.  This works for most cases, but causes
a hang on the following test case:

	Client				Server
	------				------
	Open file over NFS v4.1
	Write to file
					Expire client
	Try to lock file

The server will return NFS4ERR_BADSESSION, prompting the client to
schedule recovery.  However, the client will continue placing lock
attempts and the open recovery never seems to be scheduled.  The
simplest solution is to wait for session recovery to run before retrying
the lock.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
2012-10-31 13:13:28 -04:00
Andy Adamson 5f65753033 NFSv4 set open access operation call flag in nfs4_init_opendata_res
nfs4_open_recover_helper zeros the nfs4_opendata result structures, removing
the result access_request information which leads to an XDR decode error.

Move the setting of the result access_request field to nfs4_init_opendata_res
which sets all the other required nfs4_opendata result fields and is shared
between the open and recover open paths.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-03 17:10:28 -07:00
Andy Adamson e23008ec81 NFSv4 reduce attribute requests for open reclaim
We currently make no distinction in attribute requests between normal OPENs
and OPEN with CLAIM_PREVIOUS.  This offers more possibility of failures in
the GETATTR response which foils OPEN reclaim attempts.

Reduce the requested attributes to the bare minimum needed to update the
reclaim open stateid and split nfs4_opendata_to_nfs4_state processing
accordingly.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-02 18:12:25 -07:00
Trond Myklebust 807d66d802 NFSv4: nfs4_open_done first must check that GETATTR decoded a file type
...before it can check the validity of that file type.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-02 17:09:00 -07:00
Weston Andros Adamson ae2bb03236 NFSv4: don't put ACCESS in OPEN compound if O_EXCL
Don't put an ACCESS op in OPEN compound if O_EXCL, because ACCESS
will return permission denied for all bits until close.

Fixes a regression due to commit 6168f62c (NFSv4: Add ACCESS operation to
OPEN compound)

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-02 14:56:19 -07:00
Weston Andros Adamson bbd3a8eee8 NFSv4: don't check MAY_WRITE access bit in OPEN
Don't check MAY_WRITE as a newly created file may not have write mode bits,
but POSIX allows the creating process to write regardless.
This is ok because NFSv4 OPEN ops handle write permissions correctly -
the ACCESS in the OPEN compound is to differentiate READ v EXEC permissions.

Fixes a regression due to commit 6168f62c (NFSv4: Add ACCESS operation to
OPEN compound)

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-02 14:55:41 -07:00
Trond Myklebust ee314c2a35 NFSv4.1: Handle BAD_STATEID and EXPIRED errors in layoutget
If the layoutget call returns a stateid error, we want to invalidate the
layout stateid, and/or recover the open stateid.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-02 08:34:29 -07:00
Peng Tao dc182549d4 NFS41: fix error of setting blocklayoutdriver
After commit e38eb650 (NFS: set_pnfs_layoutdriver() from
nfs4_proc_fsinfo()), set_pnfs_layoutdriver() is called inside
nfs4_proc_fsinfo(), but pnfs_blksize is not set. It causes setting
blocklayoutdriver failure and pnfsblock mount failure.

Cc: stable <stable@vger.kernel.org> [since v3.5]
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-01 15:37:39 -07:00
Chuck Lever 6f2ea7f2a3 NFS: Add nfs4_unique_id boot parameter
An optional boot parameter is introduced to allow client
administrators to specify a string that the Linux NFS client can
insert into its nfs_client_id4 id string, to make it both more
globally unique, and to ensure that it doesn't change even if the
client's nodename changes.

If this boot parameter is not specified, the client's nodename is
used, as before.

Client installation procedures can create a unique string (typically,
a UUID) which remains unchanged during the lifetime of that client
instance.  This works just like creating a UUID for the label of the
system's root and boot volumes.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-01 15:33:33 -07:00
Chuck Lever 05f4c350ee NFS: Discover NFSv4 server trunking when mounting
"Server trunking" is a fancy named for a multi-homed NFS server.
Trunking might occur if a client sends NFS requests for a single
workload to multiple network interfaces on the same server.  There
are some implications for NFSv4 state management that make it useful
for a client to know if a single NFSv4 server instance is
multi-homed.  (Note this is only a consideration for NFSv4, not for
legacy versions of NFS, which are stateless).

If a client cares about server trunking, no NFSv4 operations can
proceed until that client determines who it is talking to.  Thus
server IP trunking discovery must be done when the client first
encounters an unfamiliar server IP address.

The nfs_get_client() function walks the nfs_client_list and matches
on server IP address.  The outcome of that walk tells us immediately
if we have an unfamiliar server IP address.  It invokes
nfs_init_client() in this case.  Thus, nfs4_init_client() is a good
spot to perform trunking discovery.

Discovery requires a client to establish a fresh client ID, so our
client will now send SETCLIENTID or EXCHANGE_ID as the first NFS
operation after a successful ping, rather than waiting for an
application to perform an operation that requires NFSv4 state.

The exact process for detecting trunking is different for NFSv4.0 and
NFSv4.1, so a minorversion-specific init_client callout method is
introduced.

CLID_INUSE recovery is important for the trunking discovery process.
CLID_INUSE is a sign the server recognizes the client's nfs_client_id4
id string, but the client is using the wrong principal this time for
the SETCLIENTID operation.  The SETCLIENTID must be retried with a
series of different principals until one works, and then the rest of
trunking discovery can proceed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-01 15:33:33 -07:00
Chuck Lever e984a55a74 NFS: Use the same nfs_client_id4 for every server
Currently, when identifying itself to NFS servers, the Linux NFS
client uses a unique nfs_client_id4.id string for each server IP
address it talks with.  For example, when client A talks to server X,
the client identifies itself using a string like "AX".  The
requirements for these strings are specified in detail by RFC 3530
(and bis).

This form of client identification presents a problem for Transparent
State Migration.  When client A's state on server X is migrated to
server Y, it continues to be associated with string "AX."  But,
according to the rules of client string construction above, client
A will present string "AY" when communicating with server Y.

Server Y thus has no way to know that client A should be associated
with the state migrated from server X.  "AX" is all but abandoned,
interfering with establishing fresh state for client A on server Y.

To support transparent state migration, then, NFSv4.0 clients must
instead use the same nfs_client_id4.id string to identify themselves
to every NFS server; something like "A".

Now a client identifies itself as "A" to server X.  When a file
system on server X transitions to server Y, and client A identifies
itself as "A" to server Y, Y will know immediately that the state
associated with "A," whether it is native or migrated, is owned by
the client, and can merge both into a single lease.

As a pre-requisite to adding support for NFSv4 migration to the Linux
NFS client, this patch changes the way Linux identifies itself to NFS
servers via the SETCLIENTID (NFSv4 minor version 0) and EXCHANGE_ID
(NFSv4 minor version 1) operations.

In addition to removing the server's IP address from nfs_client_id4,
the Linux NFS client will also no longer use its own source IP address
as part of the nfs_client_id4 string.  On multi-homed clients, the
value of this address depends on the address family and network
routing used to contact the server, thus it can be different for each
server.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-01 15:33:33 -07:00
Weston Andros Adamson 6168f62cbd NFSv4: Add ACCESS operation to OPEN compound
The OPEN operation has no way to differentiate an open for read and an
open for execution - both look like read to the server. This allowed
users to read files that didn't have READ access but did have EXEC access,
which is obviously wrong.

This patch adds an ACCESS call to the OPEN compound to handle the
difference between OPENs for reading and execution.  Since we're going
through the trouble of calling ACCESS, we check all possible access bits
and cache the results hopefully avoiding an ACCESS call in the future.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-01 15:20:11 -07:00
Bryan Schumaker 6938867edb NFS: Remove bad delegations during open recovery
I put the client into an open recovery loop by:
	Client: Open file
		read half
	Server: Expire client (echo 0 > /sys/kernel/debug/nfsd/forget_clients)
	Client: Drop vm cache (echo 3 > /proc/sys/vm/drop_caches)
		finish reading file

This causes a loop because the client never updates the nfs4_state after
discovering that the delegation is invalid.  This means it will keep
trying to read using the bad delegation rather than attempting to re-open
the file.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
CC: stable@vger.kernel.org [3.4+]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-01 15:17:25 -07:00
Bryan Schumaker fcb6d9c6b7 NFS: Always use the open stateid when checking for expired opens
If we are reading through a delegation, and the delegation is OK then
state->stateid will still point to a delegation stateid and not an open
stateid.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-01 15:17:17 -07:00
Trond Myklebust 849b286fd0 NFSv4.1: nfs4_proc_layoutreturn must always drop the plh_block_lgets count
Currently it does not do so if the RPC call failed to start. Fix is to
move the decrement of plh_block_lgets into nfs4_layoutreturn_release.

Also remove a redundant test of task->tk_status in nfs4_layoutreturn_done:
if lrp->res.lrs_present is set, then obviously the RPC call succeeded.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28 16:03:18 -04:00
Trond Myklebust 1f7977c136 NFSv4.1: Simplify the pNFS return-on-close code
Confine it to the nfs4_do_close() code.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28 16:03:12 -04:00
Trond Myklebust 7fdab069b7 NFSv4.1: Fix a race in the pNFS return-on-close code
If we sleep after dropping the inode->i_lock, then we are no longer
atomic with respect to the rpc_wake_up() call in pnfs_layout_remove_lseg().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28 16:03:11 -04:00
Trond Myklebust 9369a431bc NFSv4.1: Cleanup; add "pnfs_" prefix to put_lseg() and get_lseg()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28 16:03:07 -04:00
Trond Myklebust 70c3bd2bdf NFSv4.1: Cleanup; add "pnfs_" prefix to get_layout_hdr() and put_layout_hdr()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28 16:03:07 -04:00
Trond Myklebust a0b0a6e39b NFS: Clean up the pNFS layoutget interface
Ensure that we do return errors from nfs4_proc_layoutget() and that we
don't mark the layout as having failed if the error was due to a
signal or resource problem on the client side.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28 16:03:06 -04:00
Trond Myklebust 795a88c968 NFSv4: Convert the nfs4_lock_state->ls_flags to a bit field
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28 16:03:04 -04:00
Trond Myklebust 2a369153c8 NFS: Clean up helper function nfs4_select_rw_stateid()
We want to be able to pass on the information that the page was not
dirtied under a lock. Instead of adding a flag parameter, do this
by passing a pointer to a 'struct nfs_lock_owner' that may be NULL.

Also reuse this structure in struct nfs_lock_context to carry the
fl_owner_t and pid_t.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28 16:03:04 -04:00
Wei Yongjun e8d920c58d NFS: fix the return value check by using IS_ERR
In case of error, the function rpcauth_create() returns ERR_PTR()
and never returns NULL pointer. The NULL test in the return value
check should be replaced with IS_ERR().

dpatch engine is used to auto generated this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-25 10:36:37 -04:00
Trond Myklebust 1f1ea6c2d9 NFSv4: Fix buffer overflow checking in __nfs4_get_acl_uncached
Pass the checks made by decode_getacl back to __nfs4_get_acl_uncached
so that it knows if the acl has been truncated.

The current overflow checking is broken, resulting in Oopses on
user-triggered nfs4_getfacl calls, and is opaque to the point
where several attempts at fixing it have failed.
This patch tries to clean up the code in addition to fixing the
Oopses by ensuring that the overflow checks are performed in
a single place (decode_getacl). If the overflow check failed,
we will still be able to report the acl length, but at least
we will no longer attempt to cache the acl or copy the
truncated contents to user space.

Reported-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Sachin Prabhu <sprabhu@redhat.com>
2012-09-06 11:11:53 -04:00
Trond Myklebust 21f498c2f7 NFSv4: Fix range checking in __nfs4_get_acl_uncached and __nfs4_proc_set_acl
Ensure that the user supplied buffer size doesn't cause us to overflow
the 'pages' array.

Also fix up some confusion between the use of PAGE_SIZE and
PAGE_CACHE_SIZE when calculating buffer sizes. We're not using
the page cache for anything here.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-04 14:52:43 -04:00
Trond Myklebust c3f52af3e0 NFS: Fix the initialisation of the readdir 'cookieverf' array
When the NFS_COOKIEVERF helper macro was converted into a static
inline function in commit 99fadcd764 (nfs: convert NFS_*(inode)
helpers to static inline), we broke the initialisation of the
readdir cookies, since that depended on doing a memset with an
argument of 'sizeof(NFS_COOKIEVERF(inode))' which therefore
changed from sizeof(be32 cookieverf[2]) to sizeof(be32 *).

At this point, NFS_COOKIEVERF seems to be more of an obfuscation
than a helper, so the best thing would be to just get rid of it.

Also see: https://bugzilla.kernel.org/show_bug.cgi?id=46881

Reported-by: Andi Kleen <andi@firstfloor.org>
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
2012-09-04 14:52:42 -04:00
Trond Myklebust b291f1b1c8 NFSv4: Fix the acl cache size calculation
Currently, we do not take into account the size of the 16 byte
struct nfs4_cached_acl header, when deciding whether or not we should
cache the acl data.  Consequently, we will end up allocating an
8k buffer in order to fit a maximum size 4k acl.

This patch adjusts the calculation so that we limit the cache size
to 4k for the acl header+data.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-08-16 16:15:50 -04:00
Trond Myklebust 519d3959e3 NFSv4: Fix pointer arithmetic in decode_getacl
Resetting the cursor xdr->p to a previous value is not a safe
practice: if the xdr_stream has crossed out of the initial iovec,
then a bunch of other fields would need to be reset too.

Fix this issue by using xdr_enter_page() so that the buffer gets
page aligned at the bitmap _before_ we decode it.

Also fix the confusion of the ACL length with the page buffer length
by not adding the base offset to the ACL length...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
2012-08-16 16:15:50 -04:00
Trond Myklebust 47fbf7976e NFSv4.1: Remove a bogus BUG_ON() in nfs4_layoutreturn_done
Ever since commit 0a57cdac3f (NFSv4.1 send layoutreturn to fence
disconnected data server) we've been sending layoutreturn calls
while there is potentially still outstanding I/O to the data
servers. The reason we do this is to avoid races between replayed
writes to the MDS and the original writes to the DS.

When this happens, the BUG_ON() in nfs4_layoutreturn_done can
be triggered because it assumes that we would never call
layoutreturn without knowing that all I/O to the DS is
finished. The fix is to remove the BUG_ON() now that the
assumptions behind the test are obsolete.

Reported-by: Boaz Harrosh <bharrosh@panasas.com>
Reported-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [>=3.5]
2012-08-08 16:03:13 -04:00
Idan Kedar 21d1f58aed pnfs: nfs4_proc_layoutget returns void
since the only user of nfs4_proc_layoutget is send_layoutget, which
ignores its return value, there is no reason to return any value.

Signed-off-by: Idan Kedar <idank@tonian.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-08-02 17:39:06 -04:00
Idan Kedar 8554116e17 pnfs: defer release of pages in layoutget
we have encountered a bug whereby reading a lot of files (copying
fedora's /bin) from a pNFS mount and hitting Ctrl+C in the middle caused
a general protection fault in xdr_shrink_bufhead. this function is
called when decoding the response from LAYOUTGET. the decoding is done
by a worker thread, and the caller of LAYOUTGET waits for the worker
thread to complete.

hitting Ctrl+C caused the synchronous wait to end and the next thing the
caller does is to free the pages, so when the worker thread calls
xdr_shrink_bufhead, the pages are gone. therefore, the cleanup of these
pages has been moved to nfs4_layoutget_release.

Signed-off-by: Idan Kedar <idank@tonian.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-08-02 17:38:54 -04:00
Bryan Schumaker fac1e8e4ef NFS: Keep module parameters in the generic NFS client
Otherwise we break backwards compatibility when v4 becomes a modules.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-30 19:06:31 -04:00