Commit Graph

234004 Commits

Author SHA1 Message Date
Trond Myklebust a8de240a90 SUNRPC: Convert struct rpc_xprt to use atomic_t counters
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-17 12:38:59 -04:00
Trond Myklebust e020c6800c SUNRPC: Ensure we always run the tk_callback before tk_action
This fixes a race in which the task->tk_callback() puts the rpc_task
to sleep, setting a new callback. Under certain circumstances, the current
code may end up executing the task->tk_action before it gets round to the
callback.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
2011-03-17 12:38:41 -04:00
Randy Dunlap 986d4abbdd sunrpc: fix printk format warning
Fix printk format build warning:

net/sunrpc/xprtrdma/verbs.c:1463: warning: format '%llx' expects type 'long long unsigned int', but argument 3 has type 'dma_addr_t'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-15 20:17:32 -04:00
j223yang@asset.uwaterloo.ca 4d4a76f330 xprt: remove redundant null check
'req' is dereferenced before checked for NULL.
The patch simply removes the check.

Signed-off-by: Jinqiu Yang<crindy646@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-15 20:16:14 -04:00
Stephen Rothwell 8f68cd42d8 nfs: BKL is no longer needed, so remove the include
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-15 08:44:35 -04:00
Trond Myklebust e0dca7a05d NFS: Fix a warning in fs/nfs/idmap.c
Commit 45a52a0207 (NFS move nfs_client
initialization into nfs_get_client) introduces a new warning in
fs/nfs/idmap.c:

	‘struct rpc_timeout’ declared inside parameter list

Fix it by adding a forward declaration for the struct rpc_timeout
in include/linux/nfs_xdr.h

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-14 18:25:53 -04:00
Rob Landley c5cb09b6f8 Cleanup: Factor out some cut-and-paste code.
Factor out some cut-and-paste code in options parsing.
Saves about 800 bytes on x86-64.

Signed-off-by: Rob Landley <rlandley@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:28 -05:00
Rob Landley c12bacec45 cleanup: save 60 lines/100 bytes by combining two mostly duplicate functions.
Eliminate two mostly duplicate functions (nfs_parse_simple_hostname()
and nfs_parse_protected_hostname()) and instead just make the calling
function (nfs_parse_devname()) do everything.

Signed-off-by: Rob Landley <rlandley@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:28 -05:00
Konstantin Khlebnikov 7ec10f26e1 NFS: account direct-io into task io accounting
Account NFS direct-io reads and writes into Task I/O Accounting.
Do it before complition to handle aio.

NFS have unusual direct-io implementation,
thus accounting in generic code does not work.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:27 -05:00
Kevin Coffman f8628220bb gss:krb5 only include enctype numbers in gm_upcall_enctypes
Make the value in gm_upcall_enctypes just the enctype values.
This allows the values to be used more easily elsewhere.

Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:27 -05:00
Tom Tucker 5c635e09ce RPCRDMA: Fix FRMR registration/invalidate handling.
When the rpc_memreg_strategy is 5, FRMR are used to map RPC data.
This mode uses an FRMR to map the RPC data, then invalidates
(i.e. unregisers) the data in xprt_rdma_free. These FRMR are used
across connections on the same mount, i.e. if the connection goes
away on an idle timeout and reconnects later, the FRMR are not
destroyed and recreated.

This creates a problem for transport errors because the WR that
invalidate an FRMR may be flushed (i.e. fail) leaving the
FRMR valid. When the FRMR is later used to map an RPC it will fail,
tearing down the transport and starting over. Over time, more and
more of the FRMR pool end up in the wrong state resulting in
seemingly random disconnects.

This fix keeps track of the FRMR state explicitly by setting it's
state based on the successful completion of a reg/inv WR. If the FRMR
is ever used and found to be in the wrong state, an invalidate WR
is prepended, re-syncing the FRMR state and avoiding the connection loss.

Signed-off-by: Tom Tucker <tom@ogc.us>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:27 -05:00
Tom Tucker bd7ea31b9e RPCRDMA: Fix to XDR page base interpretation in marshalling logic.
The RPCRDMA marshalling logic assumed that xdr->page_base was an
offset into the first page of xdr->page_list. It is in fact an
offset into the xdr->page_list itself, that is, it selects the
first page in the page_list and the offset into that page.

The symptom depended in part on the rpc_memreg_strategy, if it was
FRMR, or some other one-shot mapping mode, the connection would get
torn down on a base and bounds error. When the badly marshalled RPC
was retransmitted it would reconnect, get the error, and tear down the
connection again in a loop forever. This resulted in a hung-mount. For
the other modes, it would result in silent data corruption. This bug is
most easily reproduced by writing more data than the filesystem
has space for.

This fix corrects the page_base assumption and otherwise simplifies
the iov mapping logic.

Signed-off-by: Tom Tucker <tom@ogc.us>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:27 -05:00
Trond Myklebust b064eca2cf NFSv4: Send unmapped uid/gids to the server when using auth_sys
The new behaviour is enabled using the new module parameter
'nfs4_disable_idmapping'.

Note that if the server rejects an unmapped uid or gid, then
the client will automatically switch back to using the idmapper.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:27 -05:00
Trond Myklebust 3ddeb7c5c6 NFSv4: Propagate the error NFS4ERR_BADOWNER to nfs4_do_setattr
This will be required in order to switch uid/gid mapping back on if the
admin has tried to disable it.

Note that we also propagate NFS4ERR_BADNAME at the same time, in order to
work around a Linux server bug.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:27 -05:00
Trond Myklebust e4fd72a17d NFSv4: cleanup idmapper functions to take an nfs_server argument
...instead of the nfs_client.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:26 -05:00
Trond Myklebust f0b851689a NFSv4: Send unmapped uid/gids to the server if the idmapper fails
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:26 -05:00
Trond Myklebust 5cf36cfdc8 NFSv4: If the server sends us a numeric uid/gid then accept it
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:26 -05:00
Benny Halevy 75247affd7 NFSv4.1: reject zero layout with zeroed stripe unit
Allowing stripe_unit==0 causes the client to crash later on
when dividing by zero.

Reported-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:45 -05:00
Fred Isaman 36fe432d33 NFSv4.1: Clear lseg pointer in ->doio function
Now that we have access to the pointer, clear it immediately after
the put, instead of in caller.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:45 -05:00
Fred Isaman c76069bda0 NFSv4.1: rearrange ->doio args
This will make it possible to clear the lseg pointer in the same
function as it is put, instead of in the caller nfs_pageio_doio().

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Fred Isaman a69aef1496 NFSv4.1: pnfs filelayout driver write
Allows the pnfs filelayout driver to write to the data servers.

Note that COMMIT to data servers will be implemented in a future
patch.  To avoid improper behavior, for the moment any WRITE to a data
server that would also require a COMMIT to the data server is sent
NFS_FILE_SYNC.

Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Fred Isaman 7ffd10640d NFSv4.1: remove GETATTR from ds writes
Any WRITE compound directed to a data server needs to have the
GETATTR calls suppressed.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Andy Adamson 0382b74409 NFSv4.1: implement generic pnfs layer write switch
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Fred Isaman 44b83799a9 NFSv4.1: trigger LAYOUTGET for writes
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Fred Isaman 5053aa568d NFSv4.1: Send lseg down into nfs_write_rpcsetup
We grab the lseg sent in from the doio function and attach it to
each struct nfs_write_data created.  This is how the lseg will be
sent to the layout driver.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Fred Isaman b029bc9b08 NFSv4.1: add callback to nfs4_write_done
Add callback that pnfs layout driver can use to do its own handling
of data server WRITE response.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:43 -05:00
Andy Adamson d138d5d17b NFSv4.1: rearrange nfs_write_rpcsetup
Reorder nfs_write_rpcsetup, preparing for a pnfs entry point.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:43 -05:00
Fred Isaman 80fe2b192d NFSv4.1: lseg documentation
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:43 -05:00
Andy Adamson 568e8c494d NFSv4.1: turn off pNFS on ds connection failure
If a data server is unavailable, go through MDS.

Mark the deviceid containing the data server as a negative cache entry.
Do not try to connect to any data server on a deviceid marked as a negative
cache entry. Mark any layout that tries to use the marked deviceid as failed.

Inodes with a layout marked as fails will not use the layout for I/O, and will
not perform any more layoutgets.
Inodes without a layout will still do layoutget, but the layout will get
marked immediately.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:43 -05:00
Christoph Hellwig ea8eecdd11 NFSv4.1 move deviceid cache to filelayout driver
No need for generic cache with only one user.
Keep a simple hash of deviceids in the filelayout driver.

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Acked-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:43 -05:00
Andy Adamson cbdabc7f8b NFSv4.1: filelayout async error handler
Use our own async error handler.
Mark the layout as failed and retry i/o through the MDS on specified errors.

Update the mds_offset in nfs_readpage_retry so that a failed short-read retry
to a DS gets correctly resent through the MDS.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:43 -05:00
Andy Adamson dc70d7b318 NFSv4.1: filelayout read
Attempt a pNFS file layout read by setting up the nfs_read_data struct and
calling nfs_initiate_read with the data server rpc client and the
filelayout rpc call ops.

Error handling is implemented in a subsequent patch.

Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Tested-by: Guo Mingyang <guomingyang@nrchpc.ac.cn>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:43 -05:00
Fred Isaman cfe7f4120f NFSv4.1: filelayout i/o helpers
Prepare for filelayout_read_pagelist with helper functions that find the correct
data server, filehandle, and offset.

Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Tigran Mkrtchyan <tigran@anahit.desy.de>
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:42 -05:00
Andy Adamson d83217c135 NFSv4.1: data server connection
Introduce a data server set_client and init session following the
nfs4_set_client and  nfs4_init_session convention.

Once a new nfs_client is on the nfs_client_list, the nfs_client cl_cons_state
serializes access to creating an nfs_client struct with matching properties.

Use the new nfs_get_client() that initializes new clients.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:42 -05:00
Andy Adamson 64419a9b20 NFSv4.1: generic read
Separate the rpc run portion of nfs_read_rpcsetup into a new function
nfs_initiate_read that is called for normal NFS I/O.

Add a pNFS read_pagelist function that is called instead of nfs_intitate_read
for pNFS reads.

Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:42 -05:00
Fred Isaman bae724ef95 NFSv4.1: shift pnfs_update_layout locations
Move the pnfs_update_layout call location to nfs_pageio_do_add_request().
Grab the lseg sent in the doio function to nfs_read_rpcsetup and attach
it to each nfs_read_data so it can be sent to the layout driver.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:42 -05:00
Fred Isaman 94ad1c80e2 NFSv4.1: coelesce across layout stripes
Add a pg_test layout driver hook which is used to avoid coelescing I/O across
layout stripes.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:42 -05:00
Fred Isaman d684d2ae10 NFSv4.1: lseg refcounting
Prepare put_lseg and get_lseg to be called from the pNFS I/O code.
Pull common code from pnfs_lseg_locked to call from pnfs_lseg.
Inline pnfs_lseg_locked into it's only caller.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:42 -05:00
Andy Adamson 94de8b27d0 NFSv4.1: add MDS mount DS only check
The DS only role cannot be used to mount.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:41 -05:00
Andy Adamson d6fb79d433 NFSv4.1: new flag for lease time check
Data servers cannot send nfs4_proc_get_lease_time. but still need to setup
state renewal. Add the NFS_CS_CHECK_LEASE_TIME bit to indicate if the lease
time can be checked.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:41 -05:00
Andy Adamson d3b4c9d767 NFSv4.1: new flag for state renewal check
Data servers not sharing a session with the mount MDS always have an empty
cl_superblocks list.
Replace the cl_superblocks empty list check to see if it is time to shut down
renewd with the NFS_CS_STOP_RENEW bit which is not set by such a data server.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:41 -05:00
Andy Adamson 89d1ea6579 NFSv4.1: send zero stateid seqid on v4.1 i/o
Data servers require a zero stateid seqid, and there is no advantage to not
doing the same for all NFSv4.1

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:41 -05:00
Andy Adamson 45a52a0207 NFS move nfs_client initialization into nfs_get_client
Now nfs_get_client returns an nfs_client ready to be used no matter if it was
found or created.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:41 -05:00
Andy Adamson bf9c1387ca NFSv4.1: put_layout_hdr can remove nfsi->layout
Prevents an Oops triggered by CB_LAYOUTRECALL and LAYOUTGET race on a
pnfs_layout_hdr first pnfs_layout_segment.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:41 -05:00
Andy Adamson 6f78befc41 NFSv4: remove CONFIG_NFS_V4 from nfs_read_data
Cleanup nfs_read_data. We also won't use CONFIG_NFS_V4_1 for additional
NFSv4.1 fields in subsequent patches.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:41 -05:00
Fred Isaman 136028967a NFS: change nfs_writeback_done to return void
The return values are not used by any callers.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:40 -05:00
Fred Isaman 83762c56c1 NFS: remove pointless if statement in nfs_direct_write_result
The code was doing nothing more in either branch of the if.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:40 -05:00
Fred Isaman eabf5baaaa RPC: clarify rpc_run_task error handling
rpc_run_task can only fail if it is not passed in a preallocated task.
However, that is not at all clear with the current code.  So
remove several impossible to occur failure checks.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:40 -05:00
Fred Isaman cee6a5372f RPC: remove check for impossible condition in rpc_make_runnable
queue_work() only returns 0 or 1, never a negative value.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:40 -05:00
Fred Isaman f49f9baac8 pnfs: fix pnfs lock inversion of i_lock and cl_lock
The pnfs code was using throughout the lock order i_lock, cl_lock.
This conflicts with the nfs delegation code.  Rework the pnfs code
to avoid taking both locks simultaneously.

Currently the code takes the double lock to add/remove the layout to a
nfs_client list, while atomically checking that the list of lsegs is
empty.  To avoid this, we rely on existing serializations.  When a
layout is initialized with lseg count equal zero, LAYOUTGET's
openstateid serialization is in effect, making it safe to assume it
stays zero unless we change it.  And once a layout's lseg count drops
to zero, it is set as DESTROYED and so will stay at zero.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:40 -05:00