It would be helpful if the kernel did not silently stop parsing
nfs options, but instead warned about any he does not recognize. The
attached patch adds one printk to do just that.

It took me a couple of hours to find my configuration mistake.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch add EXPORT_SYMBOL(filemap_write_and_wait) and use it.

See mm/filemap.c:

And changes the filemap_write_and_wait() and filemap_write_and_wait_range().

Current filemap_write_and_wait() doesn't wait if filemap_fdatawrite()
returns error.  However, even if filemap_fdatawrite() returned an
error, it may have submitted the partially data pages to the device.
(e.g. in the case of -ENOSPC)

<quotation>
Andrew Morton writes,

If filemap_fdatawrite() returns an error, this might be due to some
I/O problem: dead disk, unplugged cable, etc.  Given the generally
crappy quality of the kernel's handling of such exceptions, there's a
good chance that the filemap_fdatawait() will get stuck in D state
forever.
</quotation>

So, this patch doesn't wait if filemap_fdatawrite() returns the -EIO.

Trond, could you please review the nfs part?  Especially I'm not sure,
nfs must use the "filemap_fdatawrite(inode->i_mapping) == 0", or not.
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 If the loop errors, we need to exit.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 If someone changes the uid/gid mapping in userland, then we do eventually
 want those changes to be propagated to the kernel. Currently the kernel
 assumes that it may cache entries forever.

 Add an expiration time + garbage collector for idmap entries.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 inode->i_mode contains a lot more than just the mode bits. Make sure that
 we mask away this extra stuff in SETATTR calls to the server.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Clean up: Every ULP that uses the in-kernel RPC client, except the NLM
 client, sets cl_chatty.  There's no reason why NLM shouldn't set it, so
 just get rid of cl_chatty and always be verbose.

 Test-plan:
 Compile with CONFIG_NFS enabled.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Thanks to Ed Keizer for bug and root cause.  He says: "... we could only mount
 the top-level Solaris share. We could not mount deeper into the tree.
 Investigation showed that Solaris allows UNIX authenticated FSINFO only on the
 top level of the share. This is a problem because we share/export our home
 directories one level higher than we mount them. I.e. we share the partition
 and not the individual home directories. This prevented access to home
 directories."

 We still may need to try auth_sys for the case where the client doesn't have
 appropriate credentials.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 ...and ensure that nfs_update_inode() respects wcc
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Upon return of a write delegation, the server will almost always bump the
 change attribute. Ensure that we pick up that change so that we don't
 invalidate our data cache unnecessarily.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 According to RFC3530 we're supposed to cache the change attribute
 at the time the client receives a write delegation.
 If the inode is clean, a CB_GETATTR callback by the server to the
 client is supposed to return the cached change attribute.
 If, OTOH, the inode is dirty, the client should bump the cached
 change attribute by 1.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 ...and avoid calling set_page_dirty on them
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 The SuS states that a call to write() will cause mtime to be updated on
 the file. In order to satisfy that requirement, we need to flush out
 any cached writes in nfs_getattr().
 Speed things up slightly by not committing the writes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Most NFS server implementations allow up to 64KB reads and writes on the
 wire.  The Solaris NFS server allows up to a megabyte, for instance.

 Now the Linux NFS client supports transfer sizes up to 1MB, too.  This will
 help reduce protocol and context switch overhead on read/write intensive NFS
 workloads, and support larger atomic read and write operations on servers
 that support them.

 Test-plan:
 Connectathon and iozone on mount point with wsize=rsize>32768 over TCP.
 Tests with NFS over UDP to verify the maximum RPC payload size cap.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 To help NFS users and server developers, make the "inode number mismatch"
 message display more useful information.

 Test-plan:
 None.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 nfs_statfs() generates a log message when GETATTR returns an error.  This
 is usually a useless message.  Make it a dprintk.

 Test plan:
 None
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Red Hat found a problem in the error recovery logic in __init_nfs.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Replace ad hoc write parameter sanity checking in nfs_file_direct_write()
 with a call to generic_write_checks().  This should make the proper checks
 modulo the O_LARGEFILE flag, and should catch NFSv2-specific limitations by
 virtue of i_sb->s_maxbytes.

 Test plan:
 Posix compliance testing with both NFSv2 and NFSv3.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Use a cred from the nfs4_client->cl_state_owners list.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 In RFC3530, the RENEW operation is allowed to use either

 the same principal, RPC security flavour and (if RPCSEC_GSS), the same
  mechanism and service that was used for SETCLIENTID_CONFIRM

 OR

 Any principal, RPC security flavour and service combination that
 currently has an OPEN file on the server.

 Choose the latter since that doesn't require us to keep credentials for
 the same principal for the entire duration of the mount.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Convert private implementations in NFSv4 state recovery and delegation
 code to use kthreads.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Use wait_on_bit() when waiting for state recovery to complete.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Cut down on the number of unnecessary RENEW requests on the wire.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 In order to allow users to interrupt/cancel it.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Get rid of some unnecessary intermediate structures
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 When recovering from a delegation recall or a network partition, we need
 to replay open(O_RDWR), open(O_RDONLY) and open(O_WRONLY) separately.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 A closer reading of RFC3530 reveals that OPEN_DOWNGRADE must always
 specify a access modes that have been the argument of a previous OPEN
 operation.
 IOW: doing OPEN(O_RDWR) and then OPEN_DOWNGRADE(O_WRONLY) is forbidden
 unless the user called OPEN(O_WRONLY)

 In order to fix that, we really need to track the three possible open
 states separately.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 OPEN is a stateful operation, so we must ensure that it always
 completes. In order to allow users to interrupt the operation,
 we need to make the RPC call asynchronous, and then wait on
 completion (or cancel).
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Cleanup in preparation for making OPEN calls interruptible by the user.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 The NFSv4 model requires us to complete all RPC calls that might
 establish state on the server whether or not the user wants to
 interrupt it. We may also need to schedule new work (including
 new RPC calls) in order to cancel the new state.

 The asynchronous RPC model will allow us to ensure that RPC calls
 always complete, but in order to allow for "synchronous" RPC, we
 want to add the ability to wait for completion.
 The waits are, of course, interruptible.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Shrink the RPC task structure. Instead of storing separate pointers
 for task->tk_exit and task->tk_release, put them in a structure.

 Also pass the user data pointer as a parameter instead of passing it via
 task->tk_calldata. This enables us to nest callbacks.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Ensure that we always initiate flushing of data before we exit
 a single-page ->writepage() call.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

To help in reducing the number of include dependencies, several files were
touched as they were getting needed headers indirectly for stuff they use.

Thanks also to Alan Menegotto for pointing out that net/dccp/proto.c had
linux/dccp.h include twice.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>