This patch adds the readdir cache array and functions to retreive the array
stored on a cache page, clear the array by freeing allocated memory, add an
entry to the array, and search the array for a given cookie.

It then modifies readdir to make use of the new cache array.
With the new cache array method, we no longer need some of this code.

Finally, nfs_llseek_dir() will set file->f_pos to a value greater than 0 and
desc->dir_cookie to zero.  When we see this, readdir needs to find the file
at position file->f_pos from the start of the directory.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

nfs4state.c uses interfaces from ratelimit.h.  It needs to include
that header file to fix build errors:

fs/nfs/nfs4state.c:1195: warning: type defaults to 'int' in declaration of 'DEFINE_RATELIMIT_STATE'
fs/nfs/nfs4state.c:1195: warning: parameter names (without types) in function declaration
fs/nfs/nfs4state.c:1195: error: invalid storage class for function 'DEFINE_RATELIMIT_STATE'
fs/nfs/nfs4state.c:1195: error: implicit declaration of function '__ratelimit'
fs/nfs/nfs4state.c:1195: error: '_rs' undeclared (first use in this function)
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc:	Trond Myklebust <Trond.Myklebust@netapp.com>
Cc:	linux-nfs@vger.kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Otherwise, we cannot recover state correctly.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If nfs_intent_set_file() returns an error, we usually want to pass that
back up the stack.

Also ensure that nfs_open_revalidate() returns '1' on success.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the server sends us an NFS4ERR_STALE_CLIENTID while the state management
thread is busy reclaiming state, we do want to treat all state that wasn't
reclaimed before the STALE_CLIENTID as if a network partition occurred (see
the edge conditions described in RFC3530 and RFC5661).
What we do not want to do is to send an nfs4_reclaim_complete(), since we
haven't yet even started reclaiming state after the server rebooted.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

In the case of a server reboot, the state recovery thread starts by calling
nfs4_state_end_reclaim_reboot() in order to avoid edge conditions when
the server reboots while the client is in the middle of recovery.

However, if the client has already marked the nfs4_state as requiring
reboot recovery, then the above behaviour will cause the recovery thread to
treat the open as if it was part of such an edge condition: the open will
be recovered as if it was part of a lease expiration (and all the locks
will be lost).
Fix is to remove the call to nfs4_state_mark_reclaim_reboot from
nfs4_async_handle_error(), and nfs4_handle_exception(). Instead we leave it
to the recovery thread to do this for us.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

NFSv4 open recovery is currently broken: since we do not clear the
state->flags states before attempting recovery, we end up with the
'can_open_cached()' function triggering. This again leads to no OPEN call
being put on the wire.
Reported-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

In the case where we lock the page, and then find out that the page has
been thrown out of the page cache, we should just return VM_FAULT_NOPAGE.
This is what block_page_mkwrite() does in these situations.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

This patch creates a new idmapper system that uses the request-key function to
place a call into userspace to map user and group ids to names.  The old
idmapper was single threaded, which prevented more than one request from running
at a single time.  This means that a user would have to wait for an upcall to
finish before accessing a cached result.

The upcall result is stored on a keyring of type id_resolver.  See the file
Documentation/filesystems/nfs/idmapper.txt for instructions.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
[Trond: fix up the return value of nfs_idmap_lookup_name and clean up code]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We may end up removing the current entry from nfs_access_lru_list.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

WB_SYNC_NONE is supposed to mean "don't wait on anything". That should
also include not waiting for COMMIT calls to complete.

WB_SYNC_NONE is also implied when wbc->nonblocking and
wbc->for_background are set, so we can replace those checks in
nfs_commit_unstable_pages with a check for WB_SYNC_NONE.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In nfs_open_revalidate(), if the open_context() call returns an inode that
is not the same as dentry->d_inode, then we will call
put_nfs_open_context() with a valid dentry->d_inode, but without the
context being part of the nfsi->open_files list.

In this case too, we want to just skip the list removal, but we do want to
call the ->close_context() callback in order to close the NFSv4 state.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: NJeff Layton <jlayton@redhat.com>

Having to explicitly initialize sr_slotid to NFS4_MAX_SLOT_TABLE
resulted in numerous bugs.  Keeping the current slot as a pointer
to the slot table is more straight forward and robust as it's
implicitly set up to NULL wherever the seq_res member is initialized
to zeroes.
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Display the status of 'local_lock' mount option in /proc/mounts.
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

inode may be NULL when put_nfs_open_context is called from nfs_atomic_lookup
before d_add_unique(dentry, inode)
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFS clients since 2.6.12 support flock locks by emulating fcntl byte-range
locks. Due to this, some windows applications which seem to use both flock
(share mode lock mapped as flock by Samba) and fcntl locks sequentially on
the same file, can't lock as they falsely assume the file is already locked.
The problem was reported on a setup with windows clients accessing excel files
on a Samba exported share which is originally a NFS mount from a NetApp filer.

Older NFS clients (< 2.6.12) did not see this problem as flock locks were
considered local. To support legacy flock behavior, this patch adds a mount
option "-olocal_lock=" which can take the following values:

   'none'  		- Neither flock locks nor POSIX locks are local
   'flock' 		- flock locks are local
   'posix' 		- fcntl/POSIX locks are local
   'all'		- Both flock locks and POSIX locks are local

Testing:

   - This patch was tested by using -olocal_lock option with different values
     and the NLM calls were noted from the network packet captured.

     'none'  - NLM calls were seen during both flock() and fcntl(), flock lock
   	       was granted, fcntl was denied
     'flock' - no NLM calls for flock(), NLM call was seen for fcntl(),
   	       granted
     'posix' - NLM call was seen for flock() - granted, no NLM call for fcntl()
     'all'   - no NLM calls were seen during both flock() and fcntl()

   - No bugs were seen during NFSv4 locking/unlocking in general and NFSv4
     reboot recovery.

Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: Introduce a helper to '\0'-terminate XDR strings
that are placed in a page in the page cache.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

create_singlethread_workqueue() is deprecated.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This fixes an Oopsable condition that was introduced by commit
d3d4152a (nfs: make sillyrename an async
operation)
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The call to nfs_async_rename_release() after rpc_run_task() is incorrect.
The rpc_run_task() is always guaranteed to call the ->rpc_release() method.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

A synchronous rename can be interrupted by a SIGKILL. If that happens
during a sillyrename operation, it's possible for the rename call to
be sent to the server, but the task exits before processing the
reply. If this happens, the sillyrenamed file won't get cleaned up
during nfs_dentry_iput and the server is left with a dangling .nfs* file
hanging around.

Fix this problem by turning sillyrename into an asynchronous operation
and have the task doing the sillyrename just wait on the reply. If the
task is killed before the sillyrename completes, it'll still proceed
to completion.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

...since that's where most of the sillyrenaming code lives. A comment
block is added to the beginning as well to clarify how sillyrenaming
works. Also, make nfs_async_unlink static as nfs_sillyrename is the only
caller.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Right now, v3 and v4 have their own variants. Create a standard struct
that will work for v3 and v4. v2 doesn't get anything but a simple error
and so isn't affected by this.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Each NFS version has its own version of the rename args container.
Standardize them on a common one that's identical to the one NFSv4
uses.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Remove all remaining references to the struct nameidata from the low level
NFS layers. Again pass down a partially initialised struct nfs_open_context
when we want to do atomic open+create.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Remove references to 'struct nameidata' from the low-level open_revalidate
code, and replace them with a struct nfs_open_context which will be
correctly initialised upon success.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Start moving the 'struct nameidata' dependent code out of the lower level
NFS code in preparation for the removal of open intents.

Instead of the struct nameidata, we pass down a partially initialised
struct nfs_open_context that will be fully initialised by the atomic open
upon success.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

As a convenience, introduce a kernel command line option to enable
NFSROOT debugging messages.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: now that mount option parsing for nfsroot is handled
in fs/nfs/super.c, remove code in fs/nfs/nfsroot.c that is no
longer used.  This includes code that constructs the legacy
nfs_mount_data structure, and code that does a MNT call to the
server.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Replace duplicate code in NFSROOT for mounting an NFS server on '/'
with logic that uses the existing mainline text-based logic in the NFS
client.

Add documenting comments where appropriate.

Note that this means NFSROOT mounts now use the same default settings
as v2/v3 mounts done via mount(2) from user space.

  vers=3,tcp,rsize=<negotiated default>,wsize=<negotiated default>

As before, however, no version/protocol negotiation with the server is
done.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: To reduce confusion, rename nfs_root_name as nfs_root_parms,
as this buffer contains more than just the name of the remote server.

Introduce documenting comments around nfs_root_setup().
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

During boot, a random character is displayed instead of a tab.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Adam Lackorzynski reports:

with 2.6.35.2 I'm getting this reproducible Oops:

[  110.825396] BUG: unable to handle kernel NULL pointer dereference at
(null)
[  110.828638] IP: [<ffffffff811247b7>] encode_attrs+0x1a/0x2a4
[  110.828638] PGD be89f067 PUD bf18f067 PMD 0
[  110.828638] Oops: 0000 [#1] SMP
[  110.828638] last sysfs file: /sys/class/net/lo/operstate
[  110.828638] CPU 2
[  110.828638] Modules linked in: rtc_cmos rtc_core rtc_lib amd64_edac_mod
i2c_amd756 edac_core i2c_core dm_mirror dm_region_hash dm_log dm_snapshot
sg sr_mod usb_storage ohci_hcd mptspi tg3 mptscsih mptbase usbcore nls_base
[last unloaded: scsi_wait_scan]
[  110.828638]
[  110.828638] Pid: 11264, comm: setchecksum Not tainted 2.6.35.2 #1
[  110.828638] RIP: 0010:[<ffffffff811247b7>]  [<ffffffff811247b7>]
encode_attrs+0x1a/0x2a4
[  110.828638] RSP: 0000:ffff88003bf5b878  EFLAGS: 00010296
[  110.828638] RAX: ffff8800bddb48a8 RBX: ffff88003bf5bb18 RCX:
0000000000000000
[  110.828638] RDX: ffff8800be258800 RSI: 0000000000000000 RDI:
ffff88003bf5b9f8
[  110.828638] RBP: 0000000000000000 R08: ffff8800bddb48a8 R09:
0000000000000004
[  110.828638] R10: 0000000000000003 R11: ffff8800be779000 R12:
ffff8800be258800
[  110.828638] R13: ffff88003bf5b9f8 R14: ffff88003bf5bb20 R15:
ffff8800be258800
[  110.828638] FS:  0000000000000000(0000) GS:ffff880041e00000(0063)
knlGS:00000000556bd6b0
[  110.828638] CS:  0010 DS: 002b ES: 002b CR0: 000000008005003b
[  110.828638] CR2: 0000000000000000 CR3: 00000000be8ef000 CR4:
00000000000006e0
[  110.828638] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[  110.828638] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
0000000000000400
[  110.828638] Process setchecksum (pid: 11264, threadinfo
ffff88003bf5a000, task ffff88003f232210)
[  110.828638] Stack:
[  110.828638]  0000000000000000 ffff8800bfbcf920 0000000000000000
0000000000000ffe
[  110.828638] <0> 0000000000000000 0000000000000000 0000000000000000
0000000000000000
[  110.828638] <0> 0000000000000000 0000000000000000 0000000000000000
0000000000000000
[  110.828638] Call Trace:
[  110.828638]  [<ffffffff81124c1f>] ? nfs4_xdr_enc_setattr+0x90/0xb4
[  110.828638]  [<ffffffff81371161>] ? call_transmit+0x1c3/0x24a
[  110.828638]  [<ffffffff813774d9>] ? __rpc_execute+0x78/0x22a
[  110.828638]  [<ffffffff81371a91>] ? rpc_run_task+0x21/0x2b
[  110.828638]  [<ffffffff81371b7e>] ? rpc_call_sync+0x3d/0x5d
[  110.828638]  [<ffffffff8111e284>] ? _nfs4_do_setattr+0x11b/0x147
[  110.828638]  [<ffffffff81109466>] ? nfs_init_locked+0x0/0x32
[  110.828638]  [<ffffffff810ac521>] ? ifind+0x4e/0x90
[  110.828638]  [<ffffffff8111e2fb>] ? nfs4_do_setattr+0x4b/0x6e
[  110.828638]  [<ffffffff8111e634>] ? nfs4_do_open+0x291/0x3a6
[  110.828638]  [<ffffffff8111ed81>] ? nfs4_open_revalidate+0x63/0x14a
[  110.828638]  [<ffffffff811056c4>] ? nfs_open_revalidate+0xd7/0x161
[  110.828638]  [<ffffffff810a2de4>] ? do_lookup+0x1a4/0x201
[  110.828638]  [<ffffffff810a4733>] ? link_path_walk+0x6a/0x9d5
[  110.828638]  [<ffffffff810a42b6>] ? do_last+0x17b/0x58e
[  110.828638]  [<ffffffff810a5fbe>] ? do_filp_open+0x1bd/0x56e
[  110.828638]  [<ffffffff811cd5e0>] ? _atomic_dec_and_lock+0x30/0x48
[  110.828638]  [<ffffffff810a9b1b>] ? dput+0x37/0x152
[  110.828638]  [<ffffffff810ae063>] ? alloc_fd+0x69/0x10a
[  110.828638]  [<ffffffff81099f39>] ? do_sys_open+0x56/0x100
[  110.828638]  [<ffffffff81027a22>] ? ia32_sysret+0x0/0x5
[  110.828638] Code: 83 f1 01 e8 f5 ca ff ff 48 83 c4 50 5b 5d 41 5c c3 41
57 41 56 41 55 49 89 fd 41 54 49 89 d4 55 48 89 f5 53 48 81 ec 18 01 00 00
<8b> 06 89 c2 83 e2 08 83 fa 01 19 db 83 e3 f8 83 c3 18 a8 01 8d
[  110.828638] RIP  [<ffffffff811247b7>] encode_attrs+0x1a/0x2a4
[  110.828638]  RSP <ffff88003bf5b878>
[  110.828638] CR2: 0000000000000000
[  112.840396] ---[ end trace 95282e83fd77358f ]---

We need to ensure that the O_EXCL flag is turned off if the user doesn't
set O_CREAT.

Cc: stable@kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Randy Dunlap reports:

ERROR: "svc_gss_principal" [fs/nfs/nfs.ko] undefined!


because in fs/nfs/Kconfig, NFS_V4 selects RPCSEC_GSS_KRB5
and/or in fs/nfsd/Kconfig, NFSD_V4 selects RPCSEC_GSS_KRB5.

RPCSEC_GSS_KRB5 does 5 selects, but none of these is enforced/followed
by the fs/nfs[d]/Kconfig configs:

	select SUNRPC_GSS
	select CRYPTO
	select CRYPTO_MD5
	select CRYPTO_DES
	select CRYPTO_CBC
Reported-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Previous patch relied on DNS_RESOLVER setting CONFIG_KEYS
but needs to be selected in NFS config when using the new
DNS resolver
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
CC: David Howells <dhowells@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Use the kernel DNS resolver to translate hostnames to IP addresses.  Create a
new config option to choose between the legacy DNS resolver and the new
resolver.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>