With this patch NFS v2 can be disabled during Kconfig.  I default the
option to "y" to match the current behavior.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

In theory, NFS v3 can have different error versions than NFS v2. v4 is
already using its own nfs4_stat_to_errno() to map error codes, so
rather than create something in the generic client for v2 and v3 to
share I instead give v3 its own function.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This allows me to use the filehandle allocated in nfs_fs_mount() for nfs
v4 mounts instead of allocating a new one.  Rather than change
nfs4_mount() to look almost exactly like nfs_fs_mount(), I instead
remove the function.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This new function chooses between the v2/3 parser and the v4 parser by
filesystem type.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The v2/3 and v4 cases were very similar, with just a few parameters
changed.  This makes it easy to share code.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This function returns the same same return type as nfs4_try_mount() so
they two can be more easily substituted.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This field is unconditionally set while parsing mount data, so there is
no need to fill it in here.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

At this point, there are only a few small differences between these two
functions.  I can set a few function pointers in the nfs_mount_info
struct to get around these differences.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The only difference between nfs_xdev_mount() and nfs4_xdev_mount() is the
clone_super() function called to clone the super block.  I can combine
these two functions by using the fill_super field in the mount_info
structure.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The nfs4_remote_mount() function was only slightly different from the
nfs_fs_mount() function used by the generic client.  I created a new
nfs_mount_info structure to set different parameters to help combine
these functions.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This flag is numerically equivalent to NFS_MOUNT_UNSHARED, so I can
remove it to make collapsing functions more straightforward.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

I intend on creating a single nfs_fs_mount() function used by all our
mount paths.  To avoid checking between new mounts and clone mounts, I
instead pass both structures to a new function in super.c that finds the
cache key and then looks up the super cookie.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This patch splits out the NFS v4 specific functionality of
nfs4_get_root() into its own rpc_op called by the generic client, and
leaves nfs4_proc_get_rootfh() as its own stand alone function.  This
also allows me to change nfs4_remote_mount(), nfs4_xdev_mount() and
nfs4_remote_referral_mount() to use the generic client's nfs_get_root()
function.  Later patches in this series will collapse these functions
into one common function, so using the same get_root() function
everywhere simplifies future changes.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This function is really getting the root filehandle and not the root
dentry of the filesystem.  I also removed the rpc_ops lookup from
nfs4_get_rootfh() under the assumption that if we reach this function
then we already know we are using NFS v4.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>

Function rename to ensure that the functionality of nfs_unlock_request()
mirrors that of nfs_lock_request(). Then let nfs_unlock_and_release_request()
do the work of what used to be called nfs_unlock_request()...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>

We only have two places where we need to grab a reference when trying
to lock the nfs_page. We're better off making that explicit.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>

We now hold a reference to the nfs_page across the calls to
nfs_set_page_writeback and nfs_end_page_writeback, and that
means we already have a reference to the struct page.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>

We have to unlock the nfs_page before we call nfs_end_page_writeback
to avoid races with functions that expect the page to be unlocked
when PG_locked and PG_writeback are not set.
The problem is that nfs_unlock_request also releases the nfs_page,
causing a deadlock if the release of the nfs_open_context
triggers an iput() while the PG_writeback flag is still set...

The solution is to separate the unlocking and release of the nfs_page,
so that we can do the former before nfs_end_page_writeback and the
latter after.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>

Since even filemap_flush() needs to lock pages that are dirty, we
cannot risk calling it from the state manager context. Therefore,
we need to move the call to filemap_flush() to
nfs_async_inode_return_delegation().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The assumption is that if you are in a situation where you need to
return the delegation, then you should probably stop caching the
data anyway.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

If we hold a delegation then we know that it should be safe to continue
to cache the data beyond the close(). However since the process that wrote
the data may die after close(), we may still want to send the data to
server before those RPCSEC_GSS credentials expire. We therefore compromise
by starting writeback to the server, but don't wait for completion.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Fix the following sparse warnings:

fs/nfs/direct.c:221:6: warning: symbol 'nfs_direct_readpage_release' was
not declared. Should it be static?
fs/nfs/read.c:38:43: warning: non-ANSI function declaration of function
'nfs_readhdr_alloc'
fs/nfs/objlayout/objio_osd.c:214:5: warning: symbol '__alloc_objio_seg'
was not declared. Should it be static?
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>

Fix the following compile warnings:
fs/nfs/direct.c: In function 'nfs_direct_read_schedule_segment':
fs/nfs/direct.c:325:11: warning: comparison of distinct pointer types
lacks a cast [enabled by default]
fs/nfs/direct.c:325:11: warning: comparison of distinct pointer types
lacks a cast [enabled by default]
fs/nfs/direct.c:325:11: warning: comparison of distinct pointer types
lacks a cast [enabled by default]
fs/nfs/direct.c:352:27: warning: comparison of distinct pointer types
lacks a cast [enabled by default]
fs/nfs/direct.c: In function 'nfs_direct_write_schedule_segment':
fs/nfs/direct.c:622:11: warning: comparison of distinct pointer types
lacks a cast [enabled by default]
fs/nfs/direct.c:622:11: warning: comparison of distinct pointer types
lacks a cast [enabled by default]
fs/nfs/direct.c:622:11: warning: comparison of distinct pointer types
lacks a cast [enabled by default]
fs/nfs/direct.c:650:27: warning: comparison of distinct pointer types
lacks a cast [enabled by default]
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>

While the use of READDIRPLUS is significantly more efficient than
READDIR followed by many LOOKUP calls, it is still less efficient
than just READDIR if the attributes are not required.

This patch tracks when lookups are attempted on the directory,
and uses that information to selectively disable READDIRPLUS
on that directory.
The first 'readdir' call is always served using READDIRPLUS.
Subsequent calls only use READDIRPLUS if there was a successful
lookup or revalidation on a child in the mean time.

Credit for the original idea should go to Neil Brown. See:
      http://www.spinics.net/lists/linux-nfs/msg19996.html
However, the implementation in this patch differs from Neil's
in that it focuses on tracking lookups rather than calls to
stat().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Neil Brown <neilb@suse.de>

No attributes are supposed to change during a COMMIT call, so there
is no need to request post-op attributes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

We don't need cache consistency information when we're doing O_DIRECT
writes. Ditto for the case of delegated writes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Get rid of the post-op GETATTR on the directory in order to reduce
the amount of processing done on the server.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Get rid of the post-op GETATTR on the directory in order to reduce
the amount of processing done on the server.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Get rid of the post-op GETATTR on the directory in order to reduce
the amount of processing done on the server.

The cost is that if we later need to stat() the directory, then we
know that the ctime and mtime are likely to be invalid.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Now that NFSv2 and NFSv3 have simulated change attributes,
instead of using all three of mtime, ctime and change attribute to
manage data cache consistency, we can simplify the code to just use
the change attribute.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Use the ctime to simulate a change attribute for NFSv2 and NFSv3.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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

If the inode is being initialised, there is no point in
setting flags such as NFS_INO_INVALID_ACCESS,
NFS_INO_INVALID_ACL or NFS_INO_INVALID_DATA since there are
no cached access calls, acls or data caches to invalidate.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

We can always use the optimal full page write if we know that we
hold a delegation.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

We already know that the attribute cache is valid.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

If we're holding a delegation, then we already know that our
page cache is valid.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

In order to retrieve cache consistency attributes before
anyone else has a chance to change the inode, we need to
put the GETATTR op _before_ the DELEGRETURN op.

We can then use that as part of a 'nfs_post_op_update_inode_force_wcc()'
call, to ensure that we update the attributes without clearing our
cached data.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>