RFC 3530 states that for OPEN_DOWNGRADE "The share_access and share_deny
 bits specified must be exactly equal to the union of the share_access and
 share_deny bits specified for some subset of the OPENs in effect for
 current openowner on the current file.

 Setattr is currently violating the NFSv4 rules for OPEN_DOWNGRADE in that
 it may cause a downgrade from OPEN4_SHARE_ACCESS_BOTH to
 OPEN4_SHARE_ACCESS_WRITE despite the fact that there exists no open file
 with O_WRONLY access mode.

 Fix the problem by replacing nfs4_find_state() with a modified version of
 nfs_find_open_context().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 We must not remove the nfs4_state structure from the inode open lists
 before we are in sequence lock.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

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

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

 Optimise attribute revalidation when hardlinking. Add post-op attributes
 for the directory and the original inode.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 "Optional" means that the close call will not fail if the getattr
 at the end of the compound fails.
 If it does succeed, try to refresh inode attributes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Since the directory attributes change every time we CREATE a file,
 we might as well pick up the new directory attributes in the same
 compound.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Since we almost always call nfs_end_data_update() after we called
 nfs_refresh_inode(), we now end up marking the inode metadata
 as needing revalidation immediately after having updated it.

 This patch rearranges things so that we mark the inode as needing
 revalidation _before_ we call nfs_refresh_inode() on those operations
 that need it.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

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

 resp_len is passed in as buffer size to decode routine; make sure it's
 set right in case where userspace provides less than a page's worth of
 buffer.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 If the server is in the unconfirmed OPEN state for a given open owner
 and receives a second OPEN for the same open owner, it will cancel the
 state of the first request and set up an OPEN_CONFIRM for the second.

 This can cause a race that is discussed in rfc3530 on page 181.

 The following patch allows the client to recover by retrying the
 original open request.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Unless of course the open fails due to permission issues.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

 Since it appears that some servers don't...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Make NFSv4 return the fully initialized file pointer with the
 stateid that it created in the lookup w/intent.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

 Currently we fail to do so if the process was signalled.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

 We no longer need to worry about collisions between close() and the state
 recovery code, since the new close will automatically recheck the
 file state once it is done waiting on its sequence slot.

 Ditto for the nfs4_proc_locku() procedure.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 OPEN, CLOSE, etc no longer need these semaphores to ensure ordering of
 requests.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Once the state_owner and lock_owner semaphores get removed, it will be
 possible for other OPEN requests to reopen the same file if they have
 lower sequence ids than our CLOSE call.
 This patch ensures that we recheck the file state once
 nfs_wait_on_sequence() has completed waiting.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 NFSv4 file state-changing functions such as OPEN, CLOSE, LOCK,... are all
 labelled with "sequence identifiers" in order to prevent the server from
 reordering RPC requests, as this could cause its file state to
 become out of sync with the client.

 Currently the NFS client code enforces this ordering locally using
 semaphores to restrict access to structures until the RPC call is done.
 This, of course, only works with synchronous RPC calls, since the
 user process must first grab the semaphore.
 By dropping semaphores, and instead teaching the RPC engine to hold
 the RPC calls until they are ready to be sent, we can extend this
 process to work nicely with asynchronous RPC calls too.

 This patch adds a new list called "rpc_sequence" that defines the order
 of the RPC calls to be sent. We add one such list for each state_owner.
 When an RPC call is ready to be sent, it checks if it is top of the
 rpc_sequence list. If so, it proceeds. If not, it goes back to sleep,
 and loops until it hits top of the list.
 Once the RPC call has completed, it can then bump the sequence id counter,
 and remove itself from the rpc_sequence list, and then wake up the next
 sleeper.

 Note that the state_owner sequence ids and lock_owner sequence ids are
 all indexed to the same rpc_sequence list, so OPEN, LOCK,... requests
 are all ordered w.r.t. each other.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Use schedule_timeout_{,un}interruptible() instead of
set_current_state()/schedule_timeout() to reduce kernel size.  Also use helper
functions to convert between human time units and jiffies rather than constant
HZ division to avoid rounding errors.
Signed-off-by: NNishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When the client performs an exclusive create and opens the file for writing,
a Netapp filer will first create the file using the mode 01777. It does this
since an NFSv3/v4 exclusive create cannot immediately set the mode bits.
The 01777 mode then gets put into the inode->i_mode. After the file creation
is successful, we then do a setattr to change the mode to the correct value
(as per the NFS spec).

The problem is that nfs_refresh_inode() no longer updates inode->i_mode, so
the latter retains the 01777 mode. A bit later, the VFS notices this, and calls
remove_suid(). This of course now resets the file mode to inode->i_mode & 0777.
Hey presto, the file mode on the server is now magically changed to 0777. Duh...

Fixes http://bugzilla.linux-nfs.org/show_bug.cgi?id=32Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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

 Ensure that lock owner structures are not released prematurely.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 If we do not hold a valid stateid that is open for writes, there is little
 point in doing an extra open of the file, as the RFC does not appear to
 mandate this...

 Make setattr use the correct stateid if we're holding mandatory byte
 range locks.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

 Older gcc's don't like this.

 fs/nfs/nfs4proc.c:2194: field `data' has incomplete type
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 The Coverity checker noticed that such a simplification was possible.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Add nfs4_acl field to the nfs_inode, and use it to cache acls.  Only cache
 acls of size up to a page.  Also prepare for up to a page of acl data even
 when the user doesn't pass in a buffer, as when they want to get the acl
 length to decide what size buffer to allocate.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Client-side write support for NFSv4 ACLs.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Client-side support for NFSv4 ACLs.  Exports the raw xdr code via the
 system.nfs4_acl extended attribute.  It is up to userspace to decode the acl
 (and to provide correctly xdr'd acls on setxattr), and to convert to/from
 POSIX ACLs if desired.

 This patch provides only the read support.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Add {get,set,list}xattr methods for nfs4.  The new methods are no-ops, to be
 used by subsequent ACL patch.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 ACL support will require supporting additional inode operations in v4
 (getxattr, setxattr, listxattr).  This patch allows different protocol versions
 to support different inode operations by adding a file_inode_ops to the
 nfs_rpc_ops (to match the existing dir_inode_ops).
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 - Move NFSv4 state definitions into a private header file.
 - Clean up gunk in nfs_fs.h
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!