NFSv4: nfs4_do_open() is incorrectly triggering state recovery

We're seeing spurious calls to nfs4_schedule_stateid_recovery() from
nfs4_do_open() in situations where there is no trigger coming from the
server.
In theory the code path being triggered is supposed to notice that state
recovery happened while we were processing the open call result from the
server, before the open stateid is published. However in the years since
that code was added, we've also added the 'session draining' mechanism,
which ensures that the state recovery will wait until all the session
slots have been returned. In nfs4_do_open() the session slot is only
returned on exit of the function, so we don't need the legacy mechanism.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: add tracepoint to trunked nfs4_exchange_id calls

Add a tracepoint to track when the client sends EXCHANGE_ID to test
a new transport for session trunking.

nfs4_detect_session_trunking() tests for trunking and returns
EINVAL if trunking can't be done, add EINVAL mapping to
show_nfs4_status() in tracepoints.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: fix nfs4_listxattr kernel BUG at mm/usercopy.c:102

A call to listxattr() with a buffer size = 0 returns the actual
size of the buffer needed for a subsequent call. When size > 0,
nfs4_listxattr() does not return an error because either
generic_listxattr() or nfs4_listxattr_nfs4_label() consumes
exactly all the bytes then size is 0 when calling
nfs4_listxattr_nfs4_user() which then triggers the following
kernel BUG:

[ 99.403778] kernel BUG at mm/usercopy.c:102!
[ 99.404063] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
[ 99.408463] CPU: 0 PID: 3310 Comm: python3 Not tainted 6.6.0-61.fc40.aarch64 #1
[ 99.415827] Call trace:
[ 99.415985] usercopy_abort+0x70/0xa0
[ 99.416227] __check_heap_object+0x134/0x158
[ 99.416505] check_heap_object+0x150/0x188
[ 99.416696] __check_object_size.part.0+0x78/0x168
[ 99.416886] __check_object_size+0x28/0x40
[ 99.417078] listxattr+0x8c/0x120
[ 99.417252] path_listxattr+0x78/0xe0
[ 99.417476] __arm64_sys_listxattr+0x28/0x40
[ 99.417723] invoke_syscall+0x78/0x100
[ 99.417929] el0_svc_common.constprop.0+0x48/0xf0
[ 99.418186] do_el0_svc+0x24/0x38
[ 99.418376] el0_svc+0x3c/0x110
[ 99.418554] el0t_64_sync_handler+0x120/0x130
[ 99.418788] el0t_64_sync+0x194/0x198
[ 99.418994] Code: aa0003e3 d000a3e0 91310000 97f49bdb (d4210000)

Issue is reproduced when generic_listxattr() returns 'system.nfs4_acl',
thus calling lisxattr() with size = 16 will trigger the bug.

Add check on nfs4_listxattr() to return ERANGE error when it is
called with size > 0 and the return value is greater than size.

Fixes: 012a211abd5d ("NFSv4.2: hook in the user extended attribute handlers")
Signed-off-by: Jorge Mora <mora@netapp.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

filelock: split leases out of struct file_lock

Add a new struct file_lease and move the lease-specific fields from
struct file_lock to it. Convert the appropriate API calls to take
struct file_lease instead, and convert the callers to use them.

There is zero overlap between the lock manager operations for file
locks and the ones for file leases, so split the lease-related
operations off into a new lease_manager_operations struct.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-47-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

nfs: adapt to breakup of struct file_lock

Most of the existing APIs have remained the same, but subsystems that
access file_lock fields directly need to reach into struct
file_lock_core now.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-41-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

nfs: convert to using new filelock helpers

Convert to using the new file locking helper functions. Also, in later
patches we're going to introduce some temporary macros with names that
clash with the variable name in nfs4_proc_unlck. Rename it.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-11-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

NFSv4.1/pnfs: Ensure we handle the error NFS4ERR_RETURNCONFLICT

Once the client has processed the CB_LAYOUTRECALL, but has not yet
successfully returned the layout, the server is supposed to switch to
returning NFS4ERR_RETURNCONFLICT. This patch ensures that we handle
that return value correctly.

Fixes: 183d9e7b112a ("pnfs: rework LAYOUTGET retry handling")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs: Convert nfs_symlink() to use a folio

Use the folio APIs, saving about four calls to compound_head().
Convert back to a page in each of the individual protocol implementations.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: fix SP4_MACH_CRED protection for pnfs IO

If the client is doing pnfs IO and Kerberos is configured and EXCHANGEID
successfully negotiated SP4_MACH_CRED and WRITE/COMMIT are on the
list of state protected operations, then we need to make sure to
choose the DS's rpc_client structure instead of the MDS's one.

Fixes: fb91fb0ee7b2 ("NFS: Move call to nfs4_state_protect_write() to nfs4_write_setup()")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: fix handling NFS4ERR_DELAY when testing for session trunking

Currently when client sends an EXCHANGE_ID for a possible trunked
connection, for any error that happened, the trunk will be thrown
out. However, an NFS4ERR_DELAY is a transient error that should be
retried instead.

Fixes: e818bd085baf ("NFSv4.1 remove xprt from xprt_switch if session trunking test fails")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4/pnfs: Allow layoutget to return EAGAIN for softerr mounts

If we're using the 'softerr' mount option, we may want to allow
layoutget to return EAGAIN to allow knfsd server threads to return a
JUKEBOX/DELAY error to the client instead of busy waiting.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Add a parameter to limit the number of retries after NFS4ERR_DELAY

When using a 'softerr' mount, the NFSv4 client can get stuck waiting
forever while the server just returns NFS4ERR_DELAY. Among other things,
this causes the knfsd server threads to busy wait.
Add a parameter that tells the NFSv4 client how many times to retry
before giving up.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs: move nfs4_xattr_handlers to .rodata

This makes it harder for accidental or malicious changes to
nfs4_xattr_handlers at runtime.

Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20230930050033.41174-19-wedsonaf@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

NFSv4.1: fixup use EXCHGID4_FLAG_USE_PNFS_DS for DS server

This patches fixes commit 51d674a5e488 "NFSv4.1: use
EXCHGID4_FLAG_USE_PNFS_DS for DS server", purpose of that
commit was to mark EXCHANGE_ID to the DS with the appropriate
flag.

However, connection to MDS can return both EXCHGID4_FLAG_USE_PNFS_DS
and EXCHGID4_FLAG_USE_PNFS_MDS set but previous patch would only
remember the USE_PNFS_DS and for the 2nd EXCHANGE_ID send that
to the MDS.

Instead, just mark the pnfs path exclusively.

Fixes: 51d674a5e488 ("NFSv4.1: use EXCHGID4_FLAG_USE_PNFS_DS for DS server")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix a state manager thread deadlock regression

Commit 4dc73c679114 reintroduces the deadlock that was fixed by commit
aeabb3c96186 ("NFSv4: Fix a NFSv4 state manager deadlock") because it
prevents the setup of new threads to handle reboot recovery, while the
older recovery thread is stuck returning delegations.

Fixes: 4dc73c679114 ("NFSv4: keep state manager thread active if swap is enabled")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1: fix zero value filehandle in post open getattr

Currently, if the OPEN compound experiencing an error and needs to
get the file attributes separately, it will send a stand alone
GETATTR but it would use the filehandle from the results of
the OPEN compound. In case of the CLAIM_FH OPEN, nfs_openres's fh
is zero value. That generate a GETATTR that's sent with a zero
value filehandle, and results in the server returning an error.

Instead, for the CLAIM_FH OPEN, take the filehandle that was used
in the PUTFH of the OPEN compound.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1: use EXCHGID4_FLAG_USE_PNFS_DS for DS server

After receiving the location(s) of the DS server(s) in the
GETDEVINCEINFO, create the request for the clientid to such
server and indicate that the client is connecting to a DS.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.2: Rework scratch handling for READ_PLUS (again)

I found that the read code might send multiple requests using the same
nfs_pgio_header, but nfs4_proc_read_setup() is only called once. This is
how we ended up occasionally double-freeing the scratch buffer, but also
means we set a NULL pointer but non-zero length to the xdr scratch
buffer. This results in an oops the first time decoding needs to copy
something to scratch, which frequently happens when decoding READ_PLUS
hole segments.

I fix this by moving scratch handling into the pageio read code. I
provide a function to allocate scratch space for decoding read replies,
and free the scratch buffer when the nfs_pgio_header is freed.

Fixes: fbd2a05f29a9 (NFSv4.2: Rework scratch handling for READ_PLUS)
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs: Pass argument to fcntl_setlease as int

The interface for fcntl expects the argument passed for the command
F_SETLEASE to be of type int. The current code wrongly treats it as
a long. In order to avoid access to undefined bits, we should explicitly
cast the argument to int.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Kevin Brodsky <Kevin.Brodsky@arm.com>
Cc: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: David Laight <David.Laight@ACULAB.com>
Cc: Mark Rutland <Mark.Rutland@arm.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Cc: linux-morello@op-lists.linaro.org
Signed-off-by: Luca Vizzarro <Luca.Vizzarro@arm.com>
Message-Id: <20230414152459.816046-3-Luca.Vizzarro@arm.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

NFSv4: fix out path in __nfs4_get_acl_uncached

Another highly rare error case when a page allocating loop (inside
__nfs4_get_acl_uncached, this time) is not properly unwound on error.
Since pages array is allocated being uninitialized, need to free only
lower array indices. NULL checks were useful before commit 62a1573fcf84
("NFSv4 fix acl retrieval over krb5i/krb5p mounts") when the array had
been initialized to zero on stack.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 62a1573fcf84 ("NFSv4 fix acl retrieval over krb5i/krb5p mounts")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix dropped lock for racing OPEN and delegation return

Commmit f5ea16137a3f ("NFSv4: Retry LOCK on OLD_STATEID during delegation
return") attempted to solve this problem by using nfs4's generic async error
handling, but introduced a regression where v4.0 lock recovery would hang.
The additional complexity introduced by overloading that error handling is
not necessary for this case. This patch expects that commit to be
reverted.

The problem as originally explained in the above commit is:

There's a small window where a LOCK sent during a delegation return can
race with another OPEN on client, but the open stateid has not yet been
updated. In this case, the client doesn't handle the OLD_STATEID error
from the server and will lose this lock, emitting:
"NFS: nfs4_handle_delegation_recall_error: unhandled error -10024".

Fix this by using the old_stateid refresh helpers if the server replies
with OLD_STATEID.

Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Revert "NFSv4: Retry LOCK on OLD_STATEID during delegation return"

Olga Kornievskaia reports that this patch breaks NFSv4.0 state recovery.
It also introduces additional complexity in the error paths for cases not
related to the original problem. Let's revert it for now, and address the
original problem in another manner.

This reverts commit f5ea16137a3fa2858620dc9084466491c128535f.

Fixes: f5ea16137a3f ("NFSv4: Retry LOCK on OLD_STATEID during delegation return")
Reported-by: Kornievskaia, Olga <Olga.Kornievskaia@netapp.com>
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: freeze the session table upon receiving NFS4ERR_BADSESSION

When the client received NFS4ERR_BADSESSION, it schedules recovery
and start the state manager thread which in turn freezes the
session table and does not allow for any new requests to use the
no-longer valid session. However, it is possible that before
the state manager thread runs, a new operation would use the
released slot that received BADSESSION and was therefore not
updated its sequence number. Such re-use of the slot can lead
the application errors.

Fixes: 5c441544f045 ("NFSv4.x: Handle bad/dead sessions correctly in nfs41_sequence_process()")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Clean up some shutdown loops

If a SEQUENCE call receives -EIO for a shutdown client, it will retry the
RPC call. Instead of doing that for a shutdown client, just bail out.

Likewise, if the state manager decides to perform recovery for a shutdown
client, it will continuously retry. As above, just bail out.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: Fix a potential double free with READ_PLUS

kfree()-ing the scratch page isn't enough, we also need to set the pointer
back to NULL to avoid a double-free in the case of a resend.

Fixes: fbd2a05f29a9 (NFSv4.2: Rework scratch handling for READ_PLUS)
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.2: Rework scratch handling for READ_PLUS

Instead of using a tiny, static scratch buffer, we should use a kmalloc()-ed
buffer that is allocated when checking for read plus usage. This lets us
use the buffer before decoding any part of the READ_PLUS operation
instead of setting it right before segment decoding, meaning it should
be a little more robust.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix hangs when recovering open state after a server reboot

When we're using a cached open stateid or a delegation in order to avoid
sending a CLAIM_PREVIOUS open RPC call to the server, we don't have a
new open stateid to present to update_open_stateid().
Instead rely on nfs4_try_open_cached(), just as if we were doing a
normal open.

Fixes: d2bfda2e7aa0 ("NFSv4: don't reprocess cached open CLAIM_PREVIOUS")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: fix disabling of swap

When swap is activated to a file on an NFSv4 mount we arrange that the
state manager thread is always present as starting a new thread requires
memory allocations that might block waiting for swap.

Unfortunately the code for allowing the state manager thread to exit when
swap is disabled was not tested properly and does not work.
This can be seen by examining /proc/fs/nfsfs/servers after disabling swap
and unmounting the filesystem. The servers file will still list one
entry. Also a "ps" listing will show the state manager thread is still
present.

There are two problems.
1/ rpc_clnt_swap_deactivate() doesn't walk up the ->cl_parent list to
find the primary client on which the state manager runs.

2/ The thread is not woken up properly and it immediately goes back to
sleep without checking whether it is really needed. Using
nfs4_schedule_state_manager() ensures a proper wake-up.

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 4dc73c679114 ("NFSv4: keep state manager thread active if swap is enabled")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs: port xattr to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

NFS: avoid spurious warning of lost lock that is being unlocked.

When the NFSv4 state manager recovers state after a server restart, it
reports that locks have been lost if it finds any lock state for which
recovery hasn't been successful. i.e. any for which
NFS_LOCK_INITIALIZED is not set.

However it only tries to recover locks that are still linked to
inode->i_flctx. So if a lock has been removed from inode->i_flctx, but
the state for that lock has not yet been destroyed, then a spurious
warning results.

nfs4_proc_unlck() calls locks_lock_inode_wait() - which removes the lock
from ->i_flctx - before sending the unlock request to the server and
before the final nfs4_put_lock_state() is called. This allows a window
in which a spurious warning can be produced.

So add a new flag NFS_LOCK_UNLOCKING which is set once the decision has
been made to unlock the lock. This will prevent it from triggering any
warning.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: check FMODE_EXEC from open context mode in nfs4_opendata_access()

After converting file f_flags to open context mode by flags_to_mode(), open
context mode will have FMODE_EXEC when file open for exec, so we check
FMODE_EXEC from open context mode.

No functional change, just simplify the code.

Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix a deadlock between nfs4_open_recover_helper() and delegreturn

If we're asked to recover open state while a delegation return is
outstanding, then the state manager thread cannot use a cached open, so
if the server returns a delegation, we can end up deadlocked behind the
pending delegreturn.
To avoid this problem, let's just ask the server not to give us a
delegation unless we're explicitly reclaiming one.

Fixes: be36e185bd26 ("NFSv4: nfs4_open_recover_helper() must set share access")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix a credential leak in _nfs4_discover_trunking()

Fixes: 4f40a5b55446 ("NFSv4: Add an fattr allocation to _nfs4_discover_trunking()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: Fix initialisation of struct nfs4_label

The call to nfs4_label_init_security() should return a fully initialised
label.

Fixes: aa9c2669626c ("NFS: Client implementation of Labeled-NFS")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Retry LOCK on OLD_STATEID during delegation return

There's a small window where a LOCK sent during a delegation return can
race with another OPEN on client, but the open stateid has not yet been
updated. In this case, the client doesn't handle the OLD_STATEID error
from the server and will lose this lock, emitting:
"NFS: nfs4_handle_delegation_recall_error: unhandled error -10024".

Fix this by sending the task through the nfs4 error handling in
nfs4_lock_done() when we may have to reconcile our stateid with what the
server believes it to be. For this case, the result is a retry of the
LOCK operation with the updated stateid.

Reported-by: Gonzalo Siero Humet <gsierohu@redhat.com>
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Avoid memcpy() run-time warning for struct sockaddr overflows

The 'nfs_server' and 'mount_server' structures include a union of
'struct sockaddr' (with the older 16 bytes max address size) and
'struct sockaddr_storage' which is large enough to hold all the
supported sa_family types (128 bytes max size). The runtime memcpy()
buffer overflow checker is seeing attempts to write beyond the 16
bytes as an overflow, but the actual expected size is that of 'struct
sockaddr_storage'. Plumb the use of 'struct sockaddr_storage' more
completely through-out NFS, which results in adjusting the memcpy()
buffers to the correct union members. Avoids this false positive run-time
warning under CONFIG_FORTIFY_SOURCE:

memcpy: detected field-spanning write (size 28) of single field "&ctx->nfs_server.address" at fs/nfs/namespace.c:178 (size 16)

Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/all/202210110948.26b43120-yujie.liu@intel.com
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs: remove unnecessary (void*) conversions.

remove unnecessary void* type castings.

Signed-off-by: yuzhe <yuzhe@nfschina.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

freezer,sched: Rewrite core freezer logic

Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.

As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).

Specifically; the current scheme works a little like:

freezer_do_not_count();
schedule();
freezer_count();

And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.

However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.

That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.

This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.

As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:

TASK_FREEZABLE -> TASK_FROZEN
__TASK_STOPPED -> TASK_FROZEN
__TASK_TRACED -> TASK_FROZEN

The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).

The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.

With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org

NFSv4/pnfs: Fix a use-after-free bug in open

If someone cancels the open RPC call, then we must not try to free
either the open slot or the layoutget operation arguments, since they
are likely still in use by the hung RPC call.

Fixes: 6949493884fe ("NFSv4: Don't hold the layoutget locks across multiple RPC calls")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: RECLAIM_COMPLETE must handle EACCES

A client should be able to handle getting an EACCES error while doing
a mount operation to reclaim state due to NFS4CLNT_RECLAIM_REBOOT
being set. If the server returns RPC_AUTH_BADCRED because authentication
failed when we execute "exportfs -au", then RECLAIM_COMPLETE will go a
wrong way. After mount succeeds, all OPEN call will fail due to an
NFS4ERR_GRACE error being returned. This patch is to fix it by resending
a RPC request.

Signed-off-by: Zhang Xianwei <zhang.xianwei8@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Fixes: aa5190d0ed7d ("NFSv4: Kill nfs4_async_handle_error() abuses by NFSv4.1")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1 probe offline transports for trunking on session creation

Once the session is established call into the SUNRPC layer to check
if any offlined trunking connections should be re-enabled.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1 remove xprt from xprt_switch if session trunking test fails

If we are doing a session trunking test and it fails for the transport,
then remove this transport from the xprt_switch group.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1 offline trunkable transports on DESTROY_SESSION

When session is destroy, some of the transports might no longer be
valid trunks for the new session. Offline existing transports.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: Handle NFS4ERR_DELAY replies to OP_SEQUENCE correctly

Don't assume that the NFS4ERR_DELAY means that the server is processing
this slot id.

Fixes: 3453d5708b33 ("NFSv4.1: Avoid false retries when RPC calls are interrupted")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: Don't decrease the value of seq_nr_highest_sent

When we're trying to figure out what the server may or may not have seen
in terms of request numbers, do not assume that requests with a larger
number were missed, just because we saw a reply to a request with a
smaller number.

Fixes: 3453d5708b33 ("NFSv4.1: Avoid false retries when RPC calls are interrupted")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Add an fattr allocation to _nfs4_discover_trunking()

This was missed in c3ed222745d9 ("NFSv4: Fix free of uninitialized
nfs4_label on referral lookup.") and causes a panic when mounting
with '-o trunkdiscovery':

PID: 1604 TASK: ffff93dac3520000 CPU: 3 COMMAND: "mount.nfs"
#0 [ffffb79140f738f8] machine_kexec at ffffffffaec64bee
#1 [ffffb79140f73950] __crash_kexec at ffffffffaeda67fd
#2 [ffffb79140f73a18] crash_kexec at ffffffffaeda76ed
#3 [ffffb79140f73a30] oops_end at ffffffffaec2658d
#4 [ffffb79140f73a50] general_protection at ffffffffaf60111e
[exception RIP: nfs_fattr_init+0x5]
RIP: ffffffffc0c18265 RSP: ffffb79140f73b08 RFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff93dac304a800 RCX: 0000000000000000
RDX: ffffb79140f73bb0 RSI: ffff93dadc8cbb40 RDI: d03ee11cfaf6bd50
RBP: ffffb79140f73be8 R8: ffffffffc0691560 R9: 0000000000000006
R10: ffff93db3ffd3df8 R11: 0000000000000000 R12: ffff93dac4040000
R13: ffff93dac2848e00 R14: ffffb79140f73b60 R15: ffffb79140f73b30
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#5 [ffffb79140f73b08] _nfs41_proc_get_locations at ffffffffc0c73d53 [nfsv4]
#6 [ffffb79140f73bf0] nfs4_proc_get_locations at ffffffffc0c83e90 [nfsv4]
#7 [ffffb79140f73c60] nfs4_discover_trunking at ffffffffc0c83fb7 [nfsv4]
#8 [ffffb79140f73cd8] nfs_probe_fsinfo at ffffffffc0c0f95f [nfs]
#9 [ffffb79140f73da0] nfs_probe_server at ffffffffc0c1026a [nfs]
RIP: 00007f6254fce26e RSP: 00007ffc69496ac8 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6254fce26e
RDX: 00005600220a82a0 RSI: 00005600220a64d0 RDI: 00005600220a6520
RBP: 00007ffc69496c50 R8: 00005600220a8710 R9: 003035322e323231
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc69496c50
R13: 00005600220a8440 R14: 0000000000000010 R15: 0000560020650ef9
ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b

Fixes: c3ed222745d9 ("NFSv4: Fix free of uninitialized nfs4_label on referral lookup.")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1 mark qualified async operations as MOVEABLE tasks

Mark async operations such as RENAME, REMOVE, COMMIT MOVEABLE
for the nfsv4.1+ sessions.

Fixes: 85e39feead948 ("NFSv4.1 identify and mark RPC tasks that can move between transports")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix free of uninitialized nfs4_label on referral lookup.

Send along the already-allocated fattr along with nfs4_fs_locations, and
drop the memcpy of fattr. We end up growing two more allocations, but this
fixes up a crash as:

PID: 790 TASK: ffff88811b43c000 CPU: 0 COMMAND: "ls"
#0 [ffffc90000857920] panic at ffffffff81b9bfde
#1 [ffffc900008579c0] do_trap at ffffffff81023a9b
#2 [ffffc90000857a10] do_error_trap at ffffffff81023b78
#3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45
#4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de
#5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs]
#6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f
#7 [ffffc90000857c60] walk_component at ffffffff813a86c4
#8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553
#9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b

Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Fixes: 9558a007dbc3 ("NFS: Remove the label from the nfs4_lookup_res struct")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1: Enable access to the NFSv4.1 'dacl' and 'sacl' attributes

Enable access to the NFSv4 acl via the NFSv4.1 'dacl' and 'sacl'
attributes.
This allows the server to authenticate the DACL and the SACL operations
separately, since reading and/or editing the SACL is usually considered
to be a privileged operation.
It also allows the propagation of automatic inheritance information that
was not supported by the NFSv4.0 'acl' attribute.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Add encoders/decoders for the NFSv4.1 dacl and sacl attributes

Add the ability to set or retrieve the acl using the NFSv4.1 'dacl' and
'sacl' attributes to the NFSv4 xdr encoders/decoders.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Specify the type of ACL to cache

When caching a NFSv4 ACL, we want to specify whether we are caching an
NFSv4.0 type acl, the NFSv4.1 dacl or the NFSv4.1 sacl.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Don't hold the layoutget locks across multiple RPC calls

When doing layoutget as part of the open() compound, we have to be
careful to release the layout locks before we can call any further RPC
calls, such as setattr(). The reason is that those calls could trigger
a recall, which could deadlock.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Don't invalidate inode attributes on delegation return

There is no need to declare attributes such as the ctime, mtime and
block size invalid when we're just returning a delegation, so it is
inappropriate to call nfs_post_op_update_inode_force_wcc().
Instead, just call nfs_refresh_inode() after faking up the change
attribute. We know that the GETATTR op occurs before the DELEGRETURN, so
we are safe when doing this.

Fixes: 0bc2c9b4dca9 ("NFSv4: Don't discard the attributes returned by asynchronous DELEGRETURN")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4/pnfs: Handle RPC allocation errors in nfs4_proc_layoutget

If rpc_run_task() fails due to an allocation error, then bail out early.

Fixes: 910ad38697d9 ("NFS: Fix memory allocation in rpc_alloc_task()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: don't retry BIND_CONN_TO_SESSION on session error

There is no reason to retry the operation if a session error had
occurred in such case result structure isn't filled out.

Fixes: dff58530c4ca ("NFSv4.1: fix handling of backchannel binding in BIND_CONN_TO_SESSION")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: keep state manager thread active if swap is enabled

If we are swapping over NFSv4, we may not be able to allocate memory to
start the state-manager thread at the time when we need it.
So keep it always running when swap is enabled, and just signal it to
start.

This requires updating and testing the cl_swapper count on the root
rpc_clnt after following all ->cl_parent links.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1 restrict GETATTR fs_location query to the main transport

In the presence of trunking transports, it's helpful to make sure
that during the migration event, the GETATTR for fs_location attribute
happens on the main transport.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Clean up NFSv4.2 xattrs

Add a helper for the xattr mask so that we can get rid of the inlined
ifdefs.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1 support for NFS4_RESULT_PRESERVER_UNLINKED

In 4.1+, the server is allowed to set a flag
NFS4_RESULT_PRESERVE_UNLINKED in reply to the OPEN, that tells
the client that it does not need to do a silly rename of an
opened file when it's being removed.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Convert GFP_NOFS to GFP_KERNEL

Assume that sections that should not re-enter the filesystem are already
protected with memalloc_nofs_save/restore call, so relax those GFP_NOFS
instances which might be used by other contexts.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove an incorrect revalidation in nfs4_update_changeattr_locked()

In nfs4_update_changeattr_locked(), we don't need to set the
NFS_INO_REVAL_PAGECACHE flag, because we already know the value of the
change attribute, and we're already flagging the size. In fact, this
forces us to revalidate the change attribute a second time for no good
reason.
This extra flag appears to have been introduced as part of the xattr
feature, when update_changeattr_locked() was converted for use by the
xattr code.

Fixes: 1b523ca972ed ("nfs: modify update_changeattr to deal with regular files")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Fix nfs4_proc_get_locations() kernel-doc comment

Add the description of @server and @fhandle, and remove the excess
@inode in nfs4_proc_get_locations() kernel-doc comment to remove
warnings found by running scripts/kernel-doc, which is caused by
using 'make W=1'.

fs/nfs/nfs4proc.c:8219: warning: Function parameter or member 'server'
not described in 'nfs4_proc_get_locations'
fs/nfs/nfs4proc.c:8219: warning: Function parameter or member 'fhandle'
not described in 'nfs4_proc_get_locations'
fs/nfs/nfs4proc.c:8219: warning: Excess function parameter 'inode'
description in 'nfs4_proc_get_locations'

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1 test and add 4.1 trunking transport

For each location returned in FS_LOCATION query, establish a
transport to the server, send EXCHANGE_ID and test for trunking,
if successful, add the transport to the exiting client.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1 query for fs_location attr on a new file system

Query the server for other possible trunkable locations for a given
file system on a 4.1+ mount.

v2:
-- added missing static to nfs4_discover_trunking,
reported by the kernel test robot

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4 store server support for fs_location attribute

Define and store if server returns it supports fs_locations attribute
as a capability.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Allow writebacks to request 'blocks used'

When doing a non-pNFS write, allow the writeback code to specify that it
also needs to update 'blocks used'.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add a helper to remove case-insensitive aliases

When dealing with case insensitive names, the client has no idea how the
server performs the mapping, so cannot collapse the dentries into a
single representative. So both rename and unlink need to deal with the
fact that there could be several dentries representing the file, and
have to somehow force them to be revalidated. Use d_prune_aliases() as a
big hammer approach.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Add some support for case insensitive filesystems

Add capabilities to allow the NFS client to recognise when it is dealing
with case insensitive and case preserving filesystems.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: don't store 'struct cred *' in struct nfs_access_entry

Storing the 'struct cred *' in nfs_access_entry is problematic.
An active 'cred' can keep a 'struct key *' active, and a quota is
imposed on the number of such keys that a user can maintain.
Cached 'nfs_access_entry' structs have indefinite lifetime, and having
these keep 'struct key's alive imposes on that quota.

So remove the 'struct cred *' and replace it with the fields we need:
kuid_t, kgid_t, and struct group_info *

This makes the 'struct nfs_access_entry' 64 bits larger.

New function "access_cmp" is introduced which is identical to
cred_fscmp() except that the second arg is an 'nfs_access_entry', rather
than a 'cred'

Fixes: b68572e07c58 ("NFS: change access cache to use 'struct cred'.")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: pass cred explicitly for access tests

Storing the 'struct cred *' in nfs_access_entry is problematic.
An active 'cred' can keep a 'struct key *' active, and a quota is
imposed on the number of such keys that a user can maintain.
Cached 'nfs_access_entry' structs have indefinite lifetime, and having
these keep 'struct key's alive imposes on that quota.

So a future patch will remove the ->cred ref from nfs_access_entry.

To prepare, change various functions to not assume there is a 'cred' in
the nfs_access_entry, but to pass the cred around explicitly.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: change nfs_access_get_cached to only report the mask

Currently the nfs_access_get_cached family of functions report a
'struct nfs_access_entry' as the result, with both .mask and .cred set.
However the .cred is never used. This is probably good and there is no
guarantee that it won't be freed before use.

Change to only report the 'mask' - as this is all that is used or needed.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Remove the nfs4_label argument from nfs_setsecurity

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the nfs4_label argument from nfs_fhget()

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the nfs4_label argument from nfs_instantiate()

Pull the label from the fattr instead.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the nfs4_label from the nfs_setattrres

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the nfs4_label from the nfs4_getattr_res

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the f_label from the nfs4_opendata and nfs_openres

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the nfs4_label from the nfs4_lookupp_res struct

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the label from the nfs4_lookup_res struct

And usethe fattr's label field instead. I also adjust function calls to
remove labels along the way.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the nfs4_label from the nfs4_link_res struct

Again, use the fattr's label field instead.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the nfs4_label from the nfs4_create_res struct

Instead, use the label embedded in the attached fattr.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs4: take a reference on the nfs_client when running FREE_STATEID

During umount, the session slot tables are freed. If there are
outstanding FREE_STATEID tasks, a use-after-free and slab corruption can
occur when rpc_exit_task calls rpc_call_done -> nfs41_sequence_done ->
nfs4_sequence_process/nfs41_sequence_free_slot.

Prevent that from happening by taking a reference on the nfs_client in
nfs41_free_stateid and putting it in nfs41_free_stateid_release.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix a regression in nfs_set_open_stateid_locked()

If we already hold open state on the client, yet the server gives us a
completely different stateid to the one we already hold, then we
currently treat it as if it were an out-of-sequence update, and wait for
5 seconds for other updates to come in.
This commit fixes the behaviour so that we immediately start processing
of the new stateid, and then leave it to the call to
nfs4_test_and_free_stateid() to decide what to do with the old stateid.

Fixes: b4868b44c562 ("NFSv4: Wait for stateid updates after CLOSE/OPEN_DOWNGRADE")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Create an nfs4_server_set_init_caps() function

And call it before doing an FSINFO probe to reset to the baseline
capabilities before probing.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove --> and <-- dprintk call sites

dprintk call sites that display no other information than the
function name can be replaced with use of the trace "function" or
"function_graph" plug-ins.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Retrieve ACCESS on open if we're not using NFS4_CREATE_EXCLUSIVE

NFS4_CREATE_EXCLUSIVE does not allow the caller to set an access mode,
so for most Linux filesystems, the access call ends up returning no
permissions. However both NFS4_CREATE_EXCLUSIVE4_1 and
NFS4_CREATE_GUARDED allow the client to set the access mode.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

security: Return xattr name from security_dentry_init_security()

Right now security_dentry_init_security() only supports single security
label and is used by SELinux only. There are two users of this hook,
namely ceph and nfs.

NFS does not care about xattr name. Ceph hardcodes the xattr name to
security.selinux (XATTR_NAME_SELINUX).

I am making changes to fuse/virtiofs to send security label to virtiofsd
and I need to send xattr name as well. I also hardcoded the name of
xattr to security.selinux.

Stephen Smalley suggested that it probably is a good idea to modify
security_dentry_init_security() to also return name of xattr so that
we can avoid this hardcoding in the callers.

This patch adds a new parameter "const char **xattr_name" to
security_dentry_init_security() and LSM puts the name of xattr
too if caller asked for it (xattr_name != NULL).

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: James Morris <jamorris@linux.microsoft.com>
[PM: fixed typos in the commit description]
Signed-off-by: Paul Moore <paul@paul-moore.com>

NFSv4/pnfs: Clean up layout get on open

Cache the layout in the arguments so we don't have to keep looking it up
from the inode.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1 identify and mark RPC tasks that can move between transports

In preparation for when we can re-try a task on a different transport,
identify and mark such RPC tasks as moveable. Only 4.1+ operarations can
be re-tried on a different transport.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: setlease should return EAGAIN if locks are not available

Instead of returning ENOLCK when we can't hand out a lease, we should be
returning EAGAIN.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix handling of non-atomic change attrbute updates

If the change attribute update is declared to be non-atomic by the
server, or our cached value does not match the server's value before the
operation was performed, then we should declare the inode cache invalid.

On the other hand, if the change to the directory raced with a lookup or
getattr which already updated the change attribute, then optimise away
the revalidation.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Add support for application leases underpinned by a delegation

If the NFSv4 client already holds a delegation for a file, then we can
support application leases (i.e. fcntl(fd, F_SETLEASE,...)) because the
underlying delegation guarantees that the file is not being modified on
the server by another client in a way that might conflict with the lease
guarantees.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix second deadlock in nfs4_evict_inode()

If the inode is being evicted but has to return a layout first, then
that too can cause a deadlock in the corner case where the server
reboots.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix deadlock between nfs4_evict_inode() and nfs4_opendata_get_inode()

If the inode is being evicted, but has to return a delegation first,
then it can cause a deadlock in the corner case where the server reboots
before the delegreturn completes, but while the call to iget5_locked() in
nfs4_opendata_get_inode() is waiting for the inode free to complete.
Since the open call still holds a session slot, the reboot recovery
cannot proceed.

In order to break the logjam, we can turn the delegation return into a
privileged operation for the case where we're evicting the inode. We
know that in that case, there can be no other state recovery operation
that conflicts.

Reported-by: zhangxiaoxu (A) <zhangxiaoxu5@huawei.com>
Fixes: 5fcdfacc01f3 ("NFSv4: Return delegations synchronously in evict_inode")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Ensure the NFS_CAP_SECURITY_LABEL capability is set when appropriate

Commit ce62b114bbad ("NFS: Split attribute support out from the server
capabilities") removed the logic from _nfs4_server_capabilities() that
sets the NFS_CAP_SECURITY_LABEL capability based on the presence of
FATTR4_WORD2_SECURITY_LABEL in the attr_bitmask of the server's response.
Now NFS_CAP_SECURITY_LABEL is never set, which breaks labelled NFS.

This was replaced with logic that clears the NFS_ATTR_FATTR_V4_SECURITY_LABEL
bit in the newly added fattr_valid field based on the absence of
FATTR4_WORD2_SECURITY_LABEL in the attr_bitmask of the server's response.
This essentially has no effect since there's nothing looks for that bit
in fattr_supported.

So revert that part of the commit, but adding the logic that sets
NFS_CAP_SECURITY_LABEL near where the other capabilities are set in
_nfs4_server_capabilities().

Fixes: ce62b114bbad ("NFS: Split attribute support out from the server capabilities")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: nfs4_proc_set_acl needs to restore NFS_CAP_UIDGID_NOMAP on error.

Currently if __nfs4_proc_set_acl fails with NFS4ERR_BADOWNER it
re-enables the idmapper by clearing NFS_CAP_UIDGID_NOMAP before
retrying again. The NFS_CAP_UIDGID_NOMAP remains cleared even if
the retry fails. This causes problem for subsequent setattr
requests for v4 server that does not have idmapping configured.

This patch modifies nfs4_proc_set_acl to detect NFS4ERR_BADOWNER
and NFS4ERR_BADNAME and skips the retry, since the kernel isn't
involved in encoding the ACEs, and return -EINVAL.

Steps to reproduce the problem:

# mount -o vers=4.1,sec=sys server:/export/test /tmp/mnt
# touch /tmp/mnt/file1
# chown 99 /tmp/mnt/file1
# nfs4_setfacl -a A::unknown.user@xyz.com:wrtncy /tmp/mnt/file1
Failed setxattr operation: Invalid argument
# chown 99 /tmp/mnt/file1
chown: changing ownership of ‘/tmp/mnt/file1’: Invalid argument
# umount /tmp/mnt
# mount -o vers=4.1,sec=sys server:/export/test /tmp/mnt
# chown 99 /tmp/mnt/file1
#

v2: detect NFS4ERR_BADOWNER and NFS4ERR_BADNAME and skip retry
in nfs4_proc_set_acl.
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs: Use fatal_signal_pending instead of signal_pending

We set the state of the current process to TASK_KILLABLE via
prepare_to_wait(). Should we use fatal_signal_pending() to detect
the signal here?

Fixes: b4868b44c562 ("NFSv4: Wait for stateid updates after CLOSE/OPEN_DOWNGRADE")
Signed-off-by: zhouchuangao <zhouchuangao@vivo.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Split attribute support out from the server capabilities

There are lots of attributes, and they are crowding out the bit space.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Don't store NFS_INO_REVAL_FORCED

NFS_INO_REVAL_FORCED is intended to tell us that the cache needs
revalidation despite the fact that we hold a delegation. We shouldn't
need to store it anymore, though.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: link must update the inode nlink.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: nfs4_inc/dec_nlink_locked should also invalidate ctime

If the nlink changes, then so will the ctime.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Use information about the change attribute to optimise updates

If the NFSv4.2 server supports the 'change_attr_type' attribute, then
allow the client to optimise its attribute cache update strategy.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Add support for the NFSv4.2 "change_attr_type" attribute

The change_attr_type allows the server to provide a description of how
the change attribute will behave. This again will allow the client to
optimise its behaviour w.r.t. attribute revalidation.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Separate tracking of file mode cache validity from the uid/gid

chown()/chgrp() and chmod() are separate operations, and in addition,
there are mode operations that are performed automatically by the
server. So let's track mode validity separately from the file ownership
validity.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Separate tracking of file nlinks cache validity from the mode/uid/gid

Rename can cause us to revalidate the access cache, so lets track the
nlinks separately from the mode/uid/gid.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix nfs4_bitmap_copy_adjust()

Don't remove flags from the set retrieved from the cache_validity.
We do want to retrieve all attributes that are listed as being
invalid, whether or not there is a delegation set.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Don't set NFS_INO_REVAL_PAGECACHE in the inode cache validity

It is no longer necessary to preserve the NFS_INO_REVAL_PAGECACHE flag.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Replace use of NFS_INO_REVAL_PAGECACHE when checking cache validity

When checking cache validity, be more specific than just 'we want to
check the page cache validity'. In almost all cases, we want to check
that change attribute, and possibly also the size.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Add a cache validity flag argument to nfs_revalidate_inode()

Add an argument to nfs_revalidate_inode() to allow callers to specify
which attributes they need to check for validity.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: nfs4_bitmask_adjust() must not change the server global bitmasks

As currently set, the calls to nfs4_bitmask_adjust() will end up
overwriting the contents of the nfs_server cache_consistency_bitmask
field.
The intention here should be to modify a private copy of that mask in
the close/delegreturn/write arguments.

Fixes: 76bd5c016ef4 ("NFSv4: make cache consistency bitmask dynamic")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Simplify nfs4_retry_setlk()

Simplify the code that retries locks based on notification events.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

treewide: remove editor modelines and cruft

The section "19) Editor modelines and other cruft" in
Documentation/process/coding-style.rst clearly says, "Do not include any
of these in source files."

I recently receive a patch to explicitly add a new one.

Let's do treewide cleanups, otherwise some people follow the existing code
and attempt to upstream their favoriate editor setups.

It is even nicer if scripts/checkpatch.pl can check it.

If we like to impose coding style in an editor-independent manner, I think
editorconfig (patch [1]) is a saner solution.

[1] https://lore.kernel.org/lkml/20200703073143.423557-1-danny@kdrag0n.dev/

Link: https://lkml.kernel.org/r/20210324054457.1477489-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org> [auxdisplay]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nfs: we don't support removing system.nfs4_acl

The NFSv4 protocol doesn't have any notion of reomoving an attribute, so
removexattr(path,"system.nfs4_acl") doesn't make sense.

There's no documented return value. Arguably it could be EOPNOTSUPP but
I'm a little worried an application might take that to mean that we
don't support ACLs or xattrs. How about EINVAL?

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.2: fix return value of _nfs4_get_security_label()

An xattr 'get' handler is expected to return the length of the value on
success, yet _nfs4_get_security_label() (and consequently also
nfs4_xattr_get_nfs4_label(), which is used as an xattr handler) returns
just 0 on success.

Fix this by returning label.len instead, which contains the length of
the result.

Fixes: aa9c2669626c ("NFS: Client implementation of Labeled-NFS")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Fix open coded versions of nfs_set_cache_invalid() in NFSv4

nfs_set_cache_invalid() has code to handle delegations, and other
optimisations, so let's use it when appropriate.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fixes for nfs4_bitmask_adjust()

We don't want to ask for the ACL in a WRITE reply, since we don't have
a preallocated buffer.

Instead of checking NFS_INO_INVALID_ACCESS, which is really about
managing the access cache, we should look at the value of
NFS_INO_INVALID_OTHER. Also ensure we assign the mode, owner and
owner_group flags to the correct bit mask.

Finally, fix up the check for NFS_INO_INVALID_CTIME to retrieve the
ctime, and add a check for NFS_INO_INVALID_CHANGE.

Fixes: 76bd5c016ef4 ("NFSv4: make cache consistency bitmask dynamic")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly add multiple break/goto/return/fallthrough
statements instead of just letting the code fall through to the next
case.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs: remove duplicate include

'nfs42.h' is already included above and can be removed here.

Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

acl: handle idmapped mounts

The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.

The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.

In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.

Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

pNFS: We want return-on-close to complete when evicting the inode

If the inode is being evicted, it should be safe to run return-on-close,
so we should do it to ensure we don't inadvertently leak layout segments.

Fixes: 1c5bd76d17cc ("pNFS: Enable layoutreturn operation for return-on-close")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS4: Fix use-after-free in trace_event_raw_event_nfs4_set_lock

It is only safe to call the tracepoint before rpc_put_task() because
'data' is freed inside nfs4_lock_release (rpc_release).

Fixes: 48c9579a1afe ("Adding stateid information to tracepoints")
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4/pnfs: Add tracing for the deviceid cache

Add tracepoints to allow debugging of the deviceid cache.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2/pnfs: Don't use READ_PLUS with pNFS yet

We have no way of tracking server READ_PLUS support in pNFS for now, so
just disable it.

Reported-by: "Mkrtchyan, Tigran" <tigran.mkrtchyan@desy.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Disable READ_PLUS by default

We've been seeing failures with xfstests generic/091 and generic/263
when using READ_PLUS. I've made some progress on these issues, and the
tests fail later on but still don't pass. Let's disable READ_PLUS by
default until we can work out what is going on.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Handle NFS4ERR_NOT_SAME and NFSERR_BADCOOKIE from readdir calls

If the server returns NFS4ERR_NOT_SAME or tells us that the cookie is
bad in response to a READDIR call, then we should empty the page cache
so that we can fill it from scratch again.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

NFS: Allow the NFS generic code to pass in a verifier to readdir

If we're ever going to allow support for servers that use the readdir
verifier, then that use needs to be managed by the middle layers as
those need to be able to reject cookies from other verifiers.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

NFSv4.2: condition READDIR's mask for security label based on LSM state

Currently, the client will always ask for security_labels if the server
returns that it supports that feature regardless of any LSM modules
(such as Selinux) enforcing security policy. This adds performance
penalty to the READDIR operation.

Client adjusts superblock's support of the security_label based on
the server's support but also current client's configuration of the
LSM modules. Thus, prior to using the default bitmask in READDIR,
this patch checks the server's capabilities and then instructs
READDIR to remove FATTR4_WORD2_SECURITY_LABEL from the bitmask.

v5: fixing silly mistakes of the rushed v4
v4: simplifying logic
v3: changing label's initialization per Ondrej's comment
v2: dropping selinux hook and using the sb cap.

Suggested-by: Ondrej Mosnacek <omosnace@redhat.com>
Suggested-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Fixes: 2b0143b5c986 ("VFS: normal filesystems (and lustre): d_inode() annotations")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Observe the NFS_MOUNT_SOFTREVAL flag in _nfs4_proc_lookupp

We need to respect the NFS_MOUNT_SOFTREVAL flag in _nfs4_proc_lookupp,
by timing out if the server is unavailable.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: support EXCHGID4_FLAG_SUPP_FENCE_OPS 4.2 EXCHANGE_ID flag

RFC 7862 introduced a new flag that either client or server is
allowed to set: EXCHGID4_FLAG_SUPP_FENCE_OPS.

Client needs to update its bitmask to allow for this flag value.

v2: changed minor version argument to unsigned int

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Use the net namespace uniquifier if it is set

If a container sets a net namespace specific uniquifier, then use that
in the setclientid/exchangeid process.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Clean up initialisation of uniquified client id strings

When the user sets a uniquifier, then ensure we copy the string
so that calls to strlen() etc are atomic with calls to snprintf().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add READ_PLUS data segment support

This patch adds client support for decoding a single NFS4_CONTENT_DATA
segment returned by the server. This is the simplest implementation
possible, since it does not account for any hole segments in the reply.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Wait for stateid updates after CLOSE/OPEN_DOWNGRADE

Since commit 0e0cb35b417f ("NFSv4: Handle NFS4ERR_OLD_STATEID in
CLOSE/OPEN_DOWNGRADE") the following livelock may occur if a CLOSE races
with the update of the nfs_state:

Process 1 Process 2 Server
========= ========= ========
OPEN file
OPEN file
Reply OPEN (1)
Reply OPEN (2)
Update state (1)
CLOSE file (1)
Reply OLD_STATEID (1)
CLOSE file (2)
Reply CLOSE (-1)
Update state (2)
wait for state change
OPEN file
wake
CLOSE file
OPEN file
wake
CLOSE file
...
...

We can avoid this situation by not issuing an immediate retry with a bumped
seqid when CLOSE/OPEN_DOWNGRADE receives NFS4ERR_OLD_STATEID. Instead,
take the same approach used by OPEN and wait at least 5 seconds for
outstanding stateid updates to complete if we can detect that we're out of
sequence.

Note that after this change it is still possible (though unlikely) that
CLOSE waits a full 5 seconds, bumps the seqid, and retries -- and that
attempt races with another OPEN at the same time. In order to avoid this
race (which would result in the livelock), update
nfs_need_update_open_stateid() to handle the case where:
- the state is NFS_OPEN_STATE, and
- the stateid doesn't match the current open stateid

Finally, nfs_need_update_open_stateid() is modified to be idempotent and
renamed to better suit the purpose of signaling that the stateid passed
is the next stateid in sequence.

Fixes: 0e0cb35b417f ("NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: make cache consistency bitmask dynamic

Client uses static bitmask for GETATTR on CLOSE/WRITE/DELEGRETURN
and ignores the fact that it might have some attributes marked
invalid in its cache. Compared to v3 where all attributes are
retrieved in postop attributes, v4's cache is frequently out of
sync and leads to standalone GETATTRs being sent to the server.

Instead, in addition to the minimum cache consistency attributes
also check cache_validity and adjust the GETATTR request accordingly.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs4: strengthen error check to avoid unexpected result

The variable error is ssize_t, which is signed and will
cast to unsigned when comapre with variable size, so add
a check to avoid unexpected result in case of negative
value of error.

Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: remove redundant pointer clnt

The pointer clnt is being initialized with a value that is never
read and so this is assignment redundant and can be removed. The
pointer can removed because it is being used as a temporary
variable and it is clearer to make the direct assignment and remove
it completely.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Zero-stateid SETATTR should first return delegation

If a write delegation isn't available, the Linux NFS client uses
a zero-stateid when performing a SETATTR.

NFSv4.0 provides no mechanism for an NFS server to match such a
request to a particular client. It recalls all delegations for that
file, even delegations held by the client issuing the request. If
that client happens to hold a read delegation, the server will
recall it immediately, resulting in an NFS4ERR_DELAY/CB_RECALL/
DELEGRETURN sequence.

Optimize out this pipeline bubble by having the client return any
delegations it may hold on a file before it issues a
SETATTR(zero-stateid) on that file.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1 handle ERR_DELAY error reclaiming locking state on delegation recall

A client should be able to handle getting an ERR_DELAY error
while doing a LOCK call to reclaim state due to delegation being
recalled. This is a transient error that can happen due to server
moving its volumes and invalidating its file location cache and
upon reference to it during the LOCK call needing to do an
expensive lookup (leading to an ERR_DELAY error on a PUTFH).

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

nfs: Fix getxattr kernel panic and memory overflow

Move the buffer size check to decode_attr_security_label() before memcpy()
Only call memcpy() if the buffer is large enough

Fixes: aa9c2669626c ("NFS: Client implementation of Labeled-NFS")
Signed-off-by: Jeffrey Mitchell <jeffrey.mitchell@starlab.io>
[Trond: clean up duplicate test of label->len != 0]
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

freezer: Add unsafe versions of freezable_schedule_timeout_interruptible for NFS

commit 0688e64bc600 ("NFS: Allow signal interruption of NFS4ERR_DELAYed operations")
introduces nfs4_delay_interruptible which also needs an _unsafe version to
avoid the following call trace for the same reason explained in
commit 416ad3c9c006 ("freezer: add unsafe versions of freezable helpers for NFS")

CPU: 4 PID: 3968 Comm: rm Tainted: G W 5.8.0-rc4 #1
Hardware name: Marvell OcteonTX CN96XX board (DT)
Call trace:
dump_backtrace+0x0/0x1dc
show_stack+0x20/0x30
dump_stack+0xdc/0x150
debug_check_no_locks_held+0x98/0xa0
nfs4_delay_interruptible+0xd8/0x120
nfs4_handle_exception+0x130/0x170
nfs4_proc_rmdir+0x8c/0x220
nfs_rmdir+0xa4/0x360
vfs_rmdir.part.0+0x6c/0x1b0
do_rmdir+0x18c/0x210
__arm64_sys_unlinkat+0x64/0x7c
el0_svc_common.constprop.0+0x7c/0x110
do_el0_svc+0x24/0xa0
el0_sync_handler+0x13c/0x1b8
el0_sync+0x158/0x180

Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

freezer: Add unsafe version of freezable_schedule_timeout_interruptible() for NFS

commit 0688e64bc600 ("NFS: Allow signal interruption of
NFS4ERR_DELAYed operations") introduces nfs4_delay_interruptible
which also needs an _unsafe version to avoid the following call
trace for the same reason explained in commit 416ad3c9c006 ("freezer:
add unsafe versions of freezable helpers for NFS")

CPU: 4 PID: 3968 Comm: rm Tainted: G W 5.8.0-rc4 #1
Hardware name: Marvell OcteonTX CN96XX board (DT)
Call trace:
dump_backtrace+0x0/0x1dc
show_stack+0x20/0x30
dump_stack+0xdc/0x150
debug_check_no_locks_held+0x98/0xa0
nfs4_delay_interruptible+0xd8/0x120
nfs4_handle_exception+0x130/0x170
nfs4_proc_rmdir+0x8c/0x220
nfs_rmdir+0xa4/0x360
vfs_rmdir.part.0+0x6c/0x1b0
do_rmdir+0x18c/0x210
__arm64_sys_unlinkat+0x64/0x7c
el0_svc_common.constprop.0+0x7c/0x110
do_el0_svc+0x24/0xa0
el0_sync_handler+0x13c/0x1b8
el0_sync+0x158/0x180

Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

NFSv4.2: add client side xattr caching.

Implement client side caching for NFSv4.2 extended attributes. The cache
is a per-inode hashtable, with name/value entries. There is one special
entry for the listxattr cache.

NFS inodes have a pointer to a cache structure. The cache structure is
allocated on demand, freed when the cache is invalidated.

Memory shrinkers keep the size in check. Large entries (> PAGE_SIZE)
are collected by a separate shrinker, and freed more aggressively
than others.

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: hook in the user extended attribute handlers

Now that all the lower level code is there to make the RPC calls, hook
it in to the xattr handlers and the listxattr entry point, to make them
available.

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs: make the buf_to_pages_noslab function available to the nfs code

Make the buf_to_pages_noslab function available to the rest of the NFS
code. Rename it to nfs4_buf_to_pages_noslab to be consistent.

This will be used later in the NFSv4.2 xattr code.

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs: define and use the NFS_INO_INVALID_XATTR flag

Define the NFS_INO_INVALID_XATTR flag, to be used for the NFSv4.2 xattr
cache, and use it where appropriate.

No functional change as yet.

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs: modify update_changeattr to deal with regular files

Until now, change attributes in change_info form were only returned by
directory operations. However, they are also used for the RFC 8276
extended attribute operations, which work on both directories
and regular files. Modify update_changeattr to deal:

* Rename it to nfs4_update_changeattr and make it non-static.
* Don't always use INO_INVALID_DATA, this isn't needed for a
directory that only had its extended attributes changed by us.
* Existing callers now always pass in INO_INVALID_DATA.

For the current callers of this function, behavior is unchanged.

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: query the extended attribute access bits

RFC 8276 defines separate ACCESS bits for extended attribute checking.
Query them in nfs_do_access and opendata.

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: query the server for extended attribute support

Query the server for extended attribute support, and record it
as the NFS_CAP_XATTR flag in the server capabilities.

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Fix interrupted slots by sending a solo SEQUENCE operation

We used to do this before 3453d5708b33, but this was changed to better
handle the NFS4ERR_SEQ_MISORDERED error code. This commit fixed the slot
re-use case when the server doesn't receive the interrupted operation,
but if the server does receive the operation then it could still end up
replying to the client with mis-matched operations from the reply cache.

We can fix this by sending a SEQUENCE to the server while recovering from
a SEQ_MISORDERED error when we detect that we are in an interrupted slot
situation.

Fixes: 3453d5708b33 (NFSv4.1: Avoid false retries when RPC calls are interrupted)
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1 fix rpc_call_done assignment for BIND_CONN_TO_SESSION

Fixes: 02a95dee8cf0 ("NFS add callback_ops to nfs4_proc_bind_conn_to_session_callback")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Don't use RPC_TASK_CRED_NOREF with delegreturn

We are not guaranteed that the credential will remain pinned.

Fixes: 612965072020 ("NFSv4: Avoid referencing the cred unnecessarily during NFSv4 I/O")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: fix handling of backchannel binding in BIND_CONN_TO_SESSION

Currently, if the client sends BIND_CONN_TO_SESSION with
NFS4_CDFC4_FORE_OR_BOTH but only gets NFS4_CDFS4_FORE back it ignores
that it wasn't able to enable a backchannel.

To make sure, the client sends BIND_CONN_TO_SESSION as the first
operation on the connections (ie., no other session compounds haven't
been sent before), and if the client's request to bind the backchannel
is not satisfied, then reset the connection and retry.

Cc: stable@vger.kernel.org
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Remove unreachable error condition due to rpc_run_task()

nfs4_proc_layoutget() invokes rpc_run_task(), which return the value to
"task". Since rpc_run_task() is impossible to return an ERR pointer,
there is no need to add the IS_ERR() condition on "task" here. So we
need to remove it.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS/pnfs: Reference the layout cred in pnfs_prepare_layoutreturn()

When we're sending a layoutreturn, ensure that we reference the
layout cred atomically with the copy of the stateid.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Beware when dereferencing the delegation cred

When we look up the delegation cred, we are usually doing so in
conjunction with a read of the stateid, and we want to ensure
that the look up is atomic with that read.

Fixes: 57f188e04773 ("NFSv4: nfs_update_inplace_delegation() should update delegation cred")
[sfr@canb.auug.org.au: Fixed up borken Fixes: line from Trond :-)]
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Ensure security label is set for root inode

When using NFSv4.2, the security label for the root inode should be set
via a call to nfs_setsecurity() during the mount process, otherwise the
inode will appear as unlabeled for up to acdirmin seconds. Currently
the label for the root inode is allocated, retrieved, and freed entirely
witin nfs4_proc_get_root().

Add a field for the label to the nfs_fattr struct, and allocate & free
the label in nfs_get_root(), where we also add a call to
nfs_setsecurity(). Note that for the call to nfs_setsecurity() to
succeed, it's necessary to also move the logic calling
security_sb_{set,clone}_security() from nfs_get_tree_common() down into
nfs_get_root()... otherwise the SBLABEL_MNT flag will not be set in the
super_block's security flags and nfs_setsecurity() will silently fail.

Reported-by: Richard Haines <richard_c_haines@btinternet.com>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Tested-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: fixed 80-char line width problems]
Signed-off-by: Paul Moore <paul@paul-moore.com>

nfs: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Avoid unnecessary credential references in layoutget

Layoutget is just using the credential attached to the open context.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Avoid referencing the cred unnecessarily during NFSv4 I/O

Avoid unnecessary references to the cred when we have already referenced
it through the open context or the open owner.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Ensure we time out if a delegreturn does not complete

We can't allow delegreturn to hold up nfs4_evict_inode() forever,
since that can cause the memory shrinkers to block. This patch
therefore ensures that we eventually time out, and complete the
reclaim of the inode.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1 make cachethis=no for writes

Turning caching off for writes on the server should improve performance.

Fixes: fba83f34119a ("NFS: Pass "privileged" value to nfs4_init_sequence()")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix races between open and dentry revalidation

We want to make sure that we revalidate the dentry if and only if
we've done an OPEN by filename.
In order to avoid races with remote changes to the directory on the
server, we want to save the verifier before calling OPEN. The exception
is if the server returned a delegation with our OPEN, as we then
know that the filename can't have changed on the server.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@gmail.com>
Tested-by: Benjamin Coddington <bcodding@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.0: nfs4_do_fsinfo() should not do implicit lease renewals

Currently, each time nfs4_do_fsinfo() is called it will do an implicit
NFS4 lease renewal, which is not compliant with the NFS4 specification.
This can result in a lease being expired by an NFS server.

Commit 83ca7f5ab31f ("NFS: Avoid PUTROOTFH when managing leases")
introduced implicit client lease renewal in nfs4_do_fsinfo(),
which can result in the NFSv4.0 lease to expire on a server side,
and servers returning NFS4ERR_EXPIRED or NFS4ERR_STALE_CLIENTID.

This can easily be reproduced by frequently unmounting a sub-mount,
then stat'ing it to get it mounted again, which will delay or even
completely prevent client from sending RENEW operations if no other
NFS operations are issued. Eventually nfs server will expire client's
lease and return an error on file access or next RENEW.

This can also happen when a sub-mount is automatically unmounted
due to inactivity (after nfs_mountpoint_expiry_timeout), then it is
mounted again via stat(). This can result in a short window during
which client's lease will expire on a server but not on a client.
This specific case was observed on production systems.

This patch removes the implicit lease renewal from nfs4_do_fsinfo().

Fixes: 83ca7f5ab31f ("NFS: Avoid PUTROOTFH when managing leases")
Signed-off-by: Robert Milkowski <rmilkowski@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: try lease recovery on NFS4ERR_EXPIRED

Currently, if an nfs server returns NFS4ERR_EXPIRED to open(),
we return EIO to applications without even trying to recover.

Fixes: 272289a3df72 ("NFSv4: nfs4_do_handle_exception() handle revoke/expiry of a single stateid")
Signed-off-by: Robert Milkowski <rmilkowski@gmail.com>
Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add softreval behaviour to nfs_lookup_revalidate()

If the server is unavaliable, we want to allow the revalidating
lookup to time out, and to default to validating the cached dentry
if the 'softreval' mount option is set.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.x recover from pre-mature loss of openstateid

Ever since the commit 0e0cb35b417f, it's possible to lose an open stateid
while retrying a CLOSE due to ERR_OLD_STATEID. Once that happens,
operations that require openstateid fail with EAGAIN which is propagated
to the application then tests like generic/446 and generic/168 fail with
"Resource temporarily unavailable".

Instead of returning this error, initiate state recovery when possible to
recover the open stateid and then try calling nfs4_select_rw_stateid()
again.

Fixes: 0e0cb35b417f ("NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4 fix acl retrieval over krb5i/krb5p mounts

For the krb5i and krb5p mount, it was problematic to truncate the
received ACL to the provided buffer because an integrity check
could not be preformed.

Instead, provide enough pages to accommodate the largest buffer
bounded by the largest RPC receive buffer size.

Note: I don't think it's possible for the ACL to be truncated now.
Thus NFS4_ACL_TRUNC flag and related code could be possibly
removed but since I'm unsure, I'm leaving it.

v2: needs +1 page.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add mount option 'softreval'

Add a mount option 'softreval' that allows attribute revalidation 'getattr'
calls to time out, and causes them to fall back to using the cached
attributes.
The use case for this option is for ensuring that we can still (slowly)
traverse paths and use cached information even when the server is down.
Once the server comes back up again, the getattr calls start succeeding,
and the caches will revalidate as usual.

The 'softreval' mount option is automatically enabled if you have
specified 'softerr'. It can be turned off using the options
'nosoftreval', or 'hard'.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS4: Remove unneeded semicolon

Fixes coccicheck warning:

fs/nfs/nfs4state.c:1138:2-3: Unneeded semicolon
fs/nfs/nfs4proc.c:6862:2-3: Unneeded semicolon
fs/nfs/nfs4proc.c:8629:2-3: Unneeded semicolon

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add fs_context support.

Add filesystem context support to NFS, parsing the options in advance and
attaching the information to struct nfs_fs_context. The highlights are:

(*) Merge nfs_mount_info and nfs_clone_mount into nfs_fs_context. This
structure represents NFS's superblock config.

(*) Make use of the VFS's parsing support to split comma-separated lists

(*) Pin the NFS protocol module in the nfs_fs_context.

(*) Attach supplementary error information to fs_context. This has the
downside that these strings must be static and can't be formatted.

(*) Remove the auxiliary file_system_type structs since the information
necessary can be conveyed in the nfs_fs_context struct instead.

(*) Root mounts are made by duplicating the config for the requested mount
so as to have the same parameters. Submounts pick up their parameters
from the parent superblock.

[AV -- retrans is u32, not string]
[SM -- Renamed cfg to ctx in a few functions in an earlier patch]
[SM -- Moved fs_context mount option parsing to an earlier patch]
[SM -- Moved fs_context error logging to a later patch]
[SM -- Fixed printks in nfs4_try_get_tree() and nfs4_get_referral_tree()]
[SM -- Added is_remount_fc() helper]
[SM -- Deferred some refactoring to a later patch]
[SM -- Fixed referral mounts, which were broken in the original patch]
[SM -- Fixed leak of nfs_fattr when fs_context is freed]

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: add declaration of current_stateid

The current_stateid is exported from nfs4state.c but not
declared in any of the headers. Add to nfs4_fs.h to
remove the following warning:

fs/nfs/nfs4state.c:80:20: warning: symbol 'current_stateid' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.x: Drop the slot if nfs4_delegreturn_prepare waits for layoutreturn

If nfs4_delegreturn_prepare needs to wait for a layoutreturn to complete
then make sure we drop the sequence slot if we hold it.

Fixes: 1c5bd76d17cc ("pNFS: Enable layoutreturn operation for return-on-close")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.x: Handle bad/dead sessions correctly in nfs41_sequence_process()

If the server returns a bad or dead session error, the we don't want
to update the session slot number, but just immediately schedule
recovery and allow it to proceed.

We can/should then remove handling in other places

Fixes: 3453d5708b33 ("NFSv4.1: Avoid false retries when RPC calls are interrupted")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Don't retry the GETATTR on old stateid in nfs4_delegreturn_done()

If the server returns NFS4ERR_OLD_STATEID, then just skip retrying the
GETATTR when replaying the delegreturn compound. We know nothing will
have changed on the server.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Handle NFS4ERR_OLD_STATEID in delegreturn

If the server returns NFS4ERR_OLD_STATEID in response to our delegreturn,
we want to sync to the most recent seqid for the delegation stateid. However
if we are already at the most recent, we have two possibilities:

- an OPEN reply is still outstanding and will return a new seqid
- an earlier OPEN reply was dropped on the floor due to a timeout.

In the latter case, we may end up unable to complete the delegreturn,
so we want to bump the seqid to a value greater than the cached value.
While this may cause us to lose the delegation in the former case,
it should now be safe to assume that the client will replay the OPEN
if necessary in order to get a new valid stateid.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: nfs4_return_incompatible_delegation() should check delegation validity

Ensure that we check that the delegation is valid in
nfs4_return_incompatible_delegation() before we try to return it.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Revoke the delegation on success in nfs4_delegreturn_done()

If the delegation was successfully returned, then mark it as revoked.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix delegation handling in update_open_stateid()

If the delegation is marked as being revoked, then don't use it in
the open state structure.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Don't allow a cached open with a revoked delegation

If the delegation is marked as being revoked, we must not use it
for cached opens.

Fixes: 869f9dfa4d6d ("NFSv4: Fix races between nfs_remove_bad_delegation() and delegation return")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix leak of clp->cl_acceptor string

Our client can issue multiple SETCLIENTID operations to the same
server in some circumstances. Ensure that calls to
nfs4_proc_setclientid() after the first one do not overwrite the
previously allocated cl_acceptor string.

unreferenced object 0xffff888461031800 (size 32):
comm "mount.nfs", pid 2227, jiffies 4294822467 (age 1407.749s)
hex dump (first 32 bytes):
6e 66 73 40 6b 6c 69 6d 74 2e 69 62 2e 31 30 31 nfs@klimt.ib.101
35 67 72 61 6e 67 65 72 2e 6e 65 74 00 00 00 00 5granger.net....
backtrace:
[<00000000ab820188>] __kmalloc+0x128/0x176
[<00000000eeaf4ec8>] gss_stringify_acceptor+0xbd/0x1a7 [auth_rpcgss]
[<00000000e85e3382>] nfs4_proc_setclientid+0x34e/0x46c [nfsv4]
[<000000003d9cf1fa>] nfs40_discover_server_trunking+0x7a/0xed [nfsv4]
[<00000000b81c3787>] nfs4_discover_server_trunking+0x81/0x244 [nfsv4]
[<000000000801b55f>] nfs4_init_client+0x1b0/0x238 [nfsv4]
[<00000000977daf7f>] nfs4_set_client+0xfe/0x14d [nfsv4]
[<0000000053a68a2a>] nfs4_create_server+0x107/0x1db [nfsv4]
[<0000000088262019>] nfs4_remote_mount+0x2c/0x59 [nfsv4]
[<00000000e84a2fd0>] legacy_get_tree+0x2d/0x4c
[<00000000797e947c>] vfs_get_tree+0x20/0xc7
[<00000000ecabaaa8>] fc_mount+0xe/0x36
[<00000000f15fafc2>] vfs_kern_mount+0x74/0x8d
[<00000000a3ff4e26>] nfs_do_root_mount+0x8a/0xa3 [nfsv4]
[<00000000d1c2b337>] nfs4_try_mount+0x58/0xad [nfsv4]
[<000000004c9bddee>] nfs_fs_mount+0x820/0x869 [nfs]

Fixes: f11b2a1cfbf5 ("nfs4: copy acceptor name from context ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS handle NFS4ERR_PARTNER_NO_AUTH error

When a destination server sends a READ to the source server it can
get a NFS4ERR_PARTNER_NO_AUTH, which means a copy needs to be
restarted.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>

NFS: inter ssc open

NFSv4.2 inter server to server copy requires the destination server to
READ the data from the source server using the provided stateid and
file handle.

Given an NFSv4 stateid and filehandle from the COPY operaion, provide the
destination server with an NFS client function to create a struct file
suitable for the destiniation server to READ the data to be copied.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Andy Adamson <andros@netapp.com>

NFS: add COPY_NOTIFY operation

Try using the delegation stateid, then the open stateid.

Only NL4_NETATTR, No support for NL4_NAME and NL4_URL.
Allow only one source server address to be returned for now.

To distinguish between same server copy offload ("intra") and
a copy between different server ("inter"), do a check of server
owner identity and also make sure server is capable of doing
a copy offload.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>

NFSv4: Handle NFS4ERR_OLD_STATEID in LOCKU

If a LOCKU request receives a NFS4ERR_OLD_STATEID, then bump the
seqid before resending. Ensure we only bump the seqid by 1.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE

If a CLOSE or OPEN_DOWNGRADE operation receives a NFS4ERR_OLD_STATEID
then bump the seqid before resending. Ensure we only bump the seqid
by 1.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix OPEN_DOWNGRADE error handling

If OPEN_DOWNGRADE returns a state error, then we want to initiate
state recovery in addition to marking the stateid as closed.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

pNFS: Handle NFS4ERR_OLD_STATEID on layoutreturn by bumping the state seqid

If a LAYOUTRETURN receives a reply of NFS4ERR_OLD_STATEID then assume we've
missed an update, and just bump the stateid.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Handle RPC level errors in LAYOUTRETURN

Handle RPC level errors by assuming that the RPC call was successful.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Clean up pNFS return-on-close error handling

Both close and delegreturn have identical code to handle pNFS
return-on-close. This patch refactors that code and places it
in pnfs.c

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Have nfs4_proc_get_lease_time() call nfs4_call_sync_custom()

This removes some code duplication, since both functions were doing the
same thing.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Have nfs41_proc_secinfo_no_name() call nfs4_call_sync_custom()

We need to use the custom rpc_task_setup here to set the
RPC_TASK_NO_ROUND_ROBIN flag on the RPC call.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Have nfs41_proc_reclaim_complete() call nfs4_call_sync_custom()

An async call followed by an rpc_wait_for_completion() is basically the
same as a synchronous call, so we can use nfs4_call_sync_custom() to
keep our custom callback ops and the RPC_TASK_NO_ROUND_ROBIN flag.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Have _nfs4_proc_secinfo() call nfs4_call_sync_custom()

We do this to set the RPC_TASK_NO_ROUND_ROBIN flag in the task_setup
structure

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Have nfs4_proc_setclientid() call nfs4_call_sync_custom()

Rather than running the task manually

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add an nfs4_call_sync_custom() function

There are a few cases where we need to manually configure the
rpc_task_setup structure to get the behavior we want.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Ensure state recovery handles ETIMEDOUT correctly

Ensure that the state recovery code handles ETIMEDOUT correctly,
and also that we set RPC_TASK_TIMEOUT when recovering open state.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix an Oops in nfs4_do_setattr

If the user specifies an open mode of 3, then we don't have a NFSv4 state
attached to the context, and so we Oops when we try to dereference it.

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 29b59f9416937 ("NFSv4: change nfs4_do_setattr to take...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.10: 991eedb1371dc: NFSv4: Only pass the...
Cc: stable@vger.kernel.org # v4.10+

NFSv4: Check the return value of update_open_stateid()

Ensure that we always check the return value of update_open_stateid()
so that we can retry if the update of local state failed. This fixes
infinite looping on state recovery.

Fixes: e23008ec81ef3 ("NFSv4 reduce attribute requests for open reclaim")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v3.7+

NFSv4.1: Fix open stateid recovery

The logic for checking in nfs41_check_open_stateid() whether the state
is supported by a delegation is inverted. In addition, it makes more
sense to perform that check before we check for expired locks.

Fixes: 8a64c4ef106d1 ("NFSv4.1: Even if the stateid is OK,...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix delegation state recovery

Once we clear the NFS_DELEGATED_STATE flag, we're telling
nfs_delegation_claim_opens() that we're done recovering all open state
for that stateid, so we really need to ensure that we test for all
open modes that are currently cached and recover them before exiting
nfs4_open_delegation_recall().

Fixes: 24311f884189d ("NFSv4: Recovery of recalled read delegations...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.3+

NFSv4: Fix a credential refcount leak in nfs41_check_delegation_stateid

It is unsafe to dereference delegation outside the rcu lock, and in
any case, the refcount is guaranteed held if cred is non-zero.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

SUNRPC: Fix up backchannel slot table accounting

Add a per-transport maximum limit in the socket case, and add
helpers to allow the NFSv4 code to discover that limit.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Validate the stateid before applying it to state recovery

If the stateid is the zero or invalid stateid, then it is pointless
to attempt to use it for recovery. In that case, try to fall back
to using the open state stateid, or just doing a general recovery
of all state on a given inode.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs4: Make nfs4_proc_get_lease_time available for nfs4.0

Compile nfs4_proc_get_lease_time, enc_get_lease_time and
dec_get_lease_time for nfs4.0. Use nfs4_sequence_done instead of
nfs41_sequence_done in nfs4_proc_get_lease_time,

Signed-off-by: Donald Buczek <buczek@molgen.mpg.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: send state management on a single connection.

With NFSv4.1, different network connections need to be explicitly
bound to a session. During session startup, this is not possible
so only a single connection must be used for session startup.

So add a task flag to disable the default round-robin choice of
connections (when nconnect > 1) and force the use of a single
connection.
Then use that flag on all requests for session management - for
consistence, include NFSv4.0 management (SETCLIENTID) and session
destruction

Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Handle open for execute correctly

When mapping the NFSv4 context to an open mode and access mode,
we need to treat the FMODE_EXEC flag differently. For the open
mode, FMODE_EXEC means we need read share access. For the access
mode checking, we need to verify that the user actually has
execute access.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS4: Only set creation opendata if O_CREAT

We can end up in nfs4_opendata_alloc during task exit, in which case
current->fs has already been cleaned up. This leads to a crash in
current_umask().

Fix this by only setting creation opendata if we are actually doing an open
with O_CREAT. We can drop the check for NULL nfs4_open_createattrs, since
O_CREAT will never be set for the recovery path.

Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1: Fix bug only first CB_NOTIFY_LOCK is handled

When a waiter is waked by CB_NOTIFY_LOCK, it will retry
nfs4_proc_setlk(). The waiter may fail to nfs4_proc_setlk() and sleep
again. However, the waiter is already removed from clp->cl_lock_waitq
when handling CB_NOTIFY_LOCK in nfs4_wake_lock_waiter(). So any
subsequent CB_NOTIFY_LOCK won't wake this waiter anymore. We should
put the waiter back to clp->cl_lock_waitq before retrying.

Cc: stable@vger.kernel.org #4.9+
Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1: Again fix a race where CB_NOTIFY_LOCK fails to wake a waiter

Commit b7dbcc0e433f "NFSv4.1: Fix a race where CB_NOTIFY_LOCK fails to wake a waiter"
found this bug. However it didn't fix it.

This commit replaces schedule_timeout() with wait_woken() and
default_wake_function() with woken_wake_function() in function
nfs4_retry_setlk() and nfs4_wake_lock_waiter(). wait_woken() uses
memory barriers in its implementation to avoid potential race condition
when putting a process into sleeping state and then waking it up.

Fixes: a1d617d8f134 ("nfs: allow blocking locks to be awoken by lock callbacks")
Cc: stable@vger.kernel.org #4.9+
Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Allow signal interruption of NFS4ERR_DELAYed operations

If the server is unable to immediately execute an RPC call, and returns
an NFS4ERR_DELAY then we can assume it is safe to interrupt the operation
in order to handle ordinary signals. This allows the application to
service timer interrupts that would otherwise have to wait until the
server is again able to respond.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

SUNRPC: Add function rpc_sleep_on_timeout()

Clean up the RPC task sleep interfaces by replacing the task->tk_timeout
'hidden parameter' to rpc_sleep_on() with a new function that takes an
absolute timeout.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

SUNRPC: Remove unused argument 'action' from rpc_sleep_on_priority()

None of the callers set the 'action' argument, so let's just remove it.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1 don't free interrupted slot on open

Allow the async rpc task for finish and update the open state if needed,
then free the slot. Otherwise, the async rpc unable to decode the reply.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Fixes: ae55e59da0e4 ("pnfs: Don't release the sequence slot...")
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Fix nfs4_lock_state refcounting in nfs4_alloc_{lock,unlock}data()

Commit 7b587e1a5a6c ("NFS: use locks_copy_lock() to copy locks.")
changed the lock copying from memcpy() to the dedicated
locks_copy_lock() function. The latter correctly increments the
nfs4_lock_state.ls_count via nfs4_fl_copy_lock(), however, this refcount
has already been incremented in the nfs4_alloc_{lock,unlock}data().
Kmemleak subsequently reports an unreferenced nfs4_lock_state object as
below (arm64 platform):

unreferenced object 0xffff8000fce0b000 (size 256):
comm "systemd-sysuser", pid 1608, jiffies 4294892825 (age 32.348s)
hex dump (first 32 bytes):
20 57 4c fb 00 80 ff ff 20 57 4c fb 00 80 ff ff WL..... WL.....
00 57 4c fb 00 80 ff ff 01 00 00 00 00 00 00 00 .WL.............
backtrace:
[<000000000d15010d>] kmem_cache_alloc+0x178/0x208
[<00000000d7c1d264>] nfs4_set_lock_state+0x124/0x1f0
[<000000009c867628>] nfs4_proc_lock+0x90/0x478
[<000000001686bd74>] do_setlk+0x64/0xe8
[<00000000e01500d4>] nfs_lock+0xe8/0x1f0
[<000000004f387d8d>] vfs_lock_file+0x18/0x40
[<00000000656ab79b>] do_lock_file_wait+0x68/0xf8
[<00000000f17c4a4b>] fcntl_setlk+0x224/0x280
[<0000000052a242c6>] do_fcntl+0x418/0x730
[<000000004f47291a>] __arm64_sys_fcntl+0x84/0xd0
[<00000000d6856e01>] el0_svc_common+0x80/0xf0
[<000000009c4bd1df>] el0_svc_handler+0x2c/0x80
[<00000000b1a0d479>] el0_svc+0x8/0xc
[<0000000056c62a0f>] 0xffffffffffffffff

This patch removes the original refcount_inc(&lsp->ls_count) that was
paired with the memcpy() lock copying.

Fixes: 7b587e1a5a6c ("NFS: use locks_copy_lock() to copy locks.")
Cc: <stable@vger.kernel.org> # 5.0.x-
Cc: NeilBrown <neilb@suse.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Handle early exit in layoutget by returning an error

If the LAYOUTGET rpc call exits early without an error, convert it to
EAGAIN.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: Add client support for the generic 'layouterror' RPC call

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: Don't process the sequence op more than once.

Ensure that if we call nfs41_sequence_process() a second time for the
same rpc_task, then we only process the results once.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: Reinitialise sequence results before retransmitting a request

If we have to retransmit a request, we should ensure that we reinitialise
the sequence results structure, since in the event of a signal
we need to treat the request as if it had not been sent.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org

NFSv4.1: Avoid false retries when RPC calls are interrupted

A 'false retry' in NFSv4.1 occurs when the client attempts to transmit a
new RPC call using a slot+sequence number combination that references an
already cached one. Currently, the Linux NFS client will do this if a
user process interrupts an RPC call that is in progress.
The problem with doing so is that we defeat the main mechanism used by
the server to differentiate between a new call and a replayed one. Even
if the server is able to perfectly cache the arguments of the old call,
it cannot know if the client intended to replay or send a new call.

The obvious fix is to bump the sequence number pre-emptively if an
RPC call is interrupted, but in order to deal with the corner cases
where the interrupted call is not actually received and processed by
the server, we need to interpret the error NFS4ERR_SEQ_MISORDERED
as a sign that we need to either wait or locate a correct sequence
number that lies between the value we sent, and the last value that
was acked by a SEQUENCE call on that slot.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Jason Tibbitts <tibbs@math.uh.edu>

NFS: Fix sparse annotations for nfs_set_open_stateid_locked()

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Fix up documentation warnings

Fix up some compiler warnings about function parameters, etc not being
correctly described or formatted.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

sunrpc: Add xprt after nfs4_test_session_trunk()

Multipathing: In case of NFSv3, rpc_clnt_test_and_add_xprt() adds
the xprt to xprt switch (i.e. xps) if rpc_call_null_helper() returns
success. But in case of NFSv4.1, it needs to do EXCHANGEID to verify
the path along with check for session trunking.

Add the xprt in nfs4_test_session_trunk() only when
nfs4_detect_session_trunking() returns success. Also release refcount
hold by rpc_clnt_setup_test_and_add_xprt().

Signed-off-by: Santosh kumar pradhan <santoshkumar.pradhan@wdc.com>
Tested-by: Suresh Jayaraman <suresh.jayaraman@wdc.com>
Reported-by: Aditya Agnihotri <aditya.agnihotri@wdc.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.

SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning. A look-up of a low-level cred will
map this to a machine credential.

Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: struct nfs_open_dir_context: convert rpc_cred pointer to cred.

Use the common 'struct cred' to pass credentials for readdir.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: change access cache to use 'struct cred'.

Rather than keying the access cache with 'struct rpc_cred',
use 'struct cred'. Then use cred_fscmp() to compare
credentials rather than comparing the raw pointer.

A benefit of this approach is that in the common case we avoid the
rpc_lookup_cred_nonblock() call which can be slow when the cred cache is large.
This also keeps many fewer items pinned in the rpc cred cache, so the
cred cache is less likely to get large.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: don't require lock for get_renew_cred or get_machine_cred

This lock is no longer necessary.

If nfs4_get_renew_cred() needs to hunt through the open-state
creds for a user cred, it still takes the lock to stablize
the rbtree, but otherwise there are no races.

Note that this completely removes the lock from nfs4_renew_state().
It appears that the original need for the locking here was removed
long ago, and there is no longer anything to protect.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: use locks_copy_lock() to copy locks.

Using memcpy() to copy lock requests leaves the various
list_head in an inconsistent state.
As we will soon attach a list of conflicting request to
another pending request, we need these lists to be consistent.
So change NFS to use locks_init_lock/locks_copy_lock instead
of memcpy.

Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

NFS: fix spelling mistake, EACCESS -> EACCES

Trivial fix to a spelling mistake of the error access name EACCESS,
rename to EACCES

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Fix dentry revalidation on NFSv4 lookup

We need to ensure that inode and dentry revalidation occurs correctly
on reopen of a file that is already open. Currently, we can end up
not revalidating either in the case of NFSv4.0, due to the 'cached open'
path.
Let's fix that by ensuring that we only do cached open for the special
cases of open recovery and delegation return.

Reported-by: Stan Hu <stanhu@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Convert struct nfs4_state to use refcount_t

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Convert lookups of the open context to RCU

Reduce contention on the inode->i_lock by ensuring that we use RCU
when looking up the NFS open context.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Don't open code clearing of delegation state

Add a helper for the case when the nfs4 open state has been set to use
a delegation stateid, and we want to revert to using the open stateid.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1 fix infinite loop on I/O.

The previous fix broke recovery of delegated stateids because it assumes
that if we did not mark the delegation as suspect, then the delegation has
effectively been revoked, and so it removes that delegation irrespectively
of whether or not it is valid and still in use. While this is "mostly
harmless" for ordinary I/O, we've seen pNFS fail with LAYOUTGET spinning
in an infinite loop while complaining that we're using an invalid stateid
(in this case the all-zero stateid).

What we rather want to do here is ensure that the delegation is always
correctly marked as needing testing when that is the case. So we want
to close the loophole offered by nfs4_schedule_stateid_recovery(),
which marks the state as needing to be reclaimed, but not the
delegation that may be backing it.

Fixes: 0e3d3e5df07dc ("NFSv4.1 fix infinite loop on IO BAD_STATEID error")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

pNFS: When updating the stateid in layoutreturn, also update the recall range

When we update the layout stateid in nfs4_layoutreturn_refresh_stateid, we
should also update the range in order to let the server know we're actually
returning everything.

Fixes: 16c278dbfa63 ("pnfs: Fix handling of NFS4ERR_OLD_STATEID replies...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix a typo in nfs4_init_channel_attrs()

The back channel size is allowed to be 1 or greater.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS add a simple sync nfs4_proc_commit after async COPY

A COPY with unstable write data needs a simple sync commit.
Filehandle value is gotten as a part of the inner loop so in
case of a reboot retry it should get the new value.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS export nfs4_async_handle_error

Make this function available to nfs42proc.c

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS OFFLOAD_CANCEL xdr

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix error handling in nfs4_sp4_select_mode()

Error code is set in the error handling cases but never used. Fix it.

Fixes: 937e3133cd0b ("NFSv4.1: Ensure we clear the SP4_MACH_CRED flags in nfs4_sp4_select_mode()")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Warning level 2 was used: -Wimplicit-fallthrough=2

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Mark the inode change attribute up to date in update_changeattr()

When we update the change attribute, we should also clear the flag that
says it is out of date.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Detect nlink changes on cross-directory renames too

If the object being renamed from one directory to another is also
a directory, then 'nlink' will change for both directories.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: bump/drop the nlink count on the parent dir when we mkdir/rmdir

Ensure that we always bump or drop the nlink count on the parent directory
when we do a mkdir or a rmdir(). This needs to be done by hand as we don't
have pre/post op attributes.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

pnfs: Fix handling of NFS4ERR_OLD_STATEID replies to layoutreturn

If the server tells us that out layoutreturn raced with another layout
update, then we must ensure that the new layout segments are not in use
before we resend with an updated layout stateid.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix _nfs4_do_setlk()

The patch to fix the case where a lock request was interrupted ended up
changing default handling of errors such as NFS4ERR_DENIED and caused the
client to immediately resend the lock request. Let's do a partial revert
of that request so that the default is now to exit, but change the way
we handle resends to take into account the fact that the user may have
interrupted the request.

Reported-by: Kenneth Johansson <ken@kenjo.org>
Fixes: a3cf9bca2ace ("NFSv4: Don't add a new lock on an interrupted wait..")
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

NFSv4 client live hangs after live data migration recovery

After a live data migration event at the NFS server, the client may send
I/O requests to the wrong server, causing a live hang due to repeated
recovery events. On the wire, this will appear as an I/O request failing
with NFS4ERR_BADSESSION, followed by successful CREATE_SESSION, repeatedly.
NFS4ERR_BADSSESSION is returned because the session ID being used was
issued by the other server and is not valid at the old server.

The failure is caused by async worker threads having cached the transport
(xprt) in the rpc_task structure. After the migration recovery completes,
the task is redispatched and the task resends the request to the wrong
server based on the old value still present in tk_xprt.

The solution is to recompute the tk_xprt field of the rpc_task structure
so that the request goes to the correct server.

Signed-off-by: Bill Baker <bill.baker@oracle.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Helen Chao <helen.chao@oracle.com>
Fixes: fb43d17210ba ("SUNRPC: Use the multipath iterator to assign a ...")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs: initiate returning delegation when reclaiming one that's been recalled

When reclaiming a delegation via CLAIM_PREVIOUS open, the server can
indicate that the delegation has been recalled since it was issued by
setting the "recalled" flag in the delegation.

Ensure that we respect the flag by initiating a delegation return when
it is set.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

pNFS: Parse the results of layoutget on open even if permissions checks fail

Even if the results of the permissions checks failed, we should parse
the results of the layout on open call so that we can return the
layout if required.
Note that we also want to ignore the sequence counter for whether or not
a layout recall occurred. If the recall pertained to our OPEN, then the
callback will know, and will attempt to wait for us to finih processing
anyway.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

introduce FMODE_CREATED and switch to it

Parallel to FILE_CREATED, goes into ->f_mode instead of *opened.
NFS is a bit of a wart here - it doesn't have file at the point
where FILE_CREATED used to be set, so we need to propagate it
there (for now). IMA is another one (here and everywhere)...

Note that this needs do_dentry_open() to leave old bits in ->f_mode
alone - we want it to preserve FMODE_CREATED if it had been already
set (no other bit can be there).

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

pNFS: Don't send layoutreturn if the layout is already invalid

If the layout was invalidated due to a reboot, then don't try to send
a layoutreturn for it.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

pNFS: Always free the session slot on error in nfs4_layoutget_handle_exception

Right now, we can call nfs_commit_inode() while holding the session slot,
which could lead to NFSv4 deadlocks. Ensure we only keep the slot if
the server returned a layout that we have to process.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: Fix the client behaviour on NFS4ERR_SEQ_FALSE_RETRY

If the server returns NFS4ERR_SEQ_FALSE_RETRY or NFS4ERR_RETRY_UNCACHED_REP,
then it thinks we're trying to replay an existing request. If so, then
let's just bump the sequence ID and retry the operation.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix a typo in nfs41_sequence_process

We want to compare the slot_id to the highest slot number advertised by the
server.

Fixes: 3be0f80b5fe9c ("NFSv4.1: Fix up replays of interrupted requests")
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.0: Remove transport protocol name from non-UCS client ID

Commit 69dd716c5ffd ("NFSv4: Add socket proto argument to
setclientid") (2007) added the transport protocol name to the client
ID string, but the patch description doesn't explain why this was
necessary.

At that time, the only transport protocol name that would have been
used is "tcp" (for both IPv4 and IPv6), resulting in no additional
distinctiveness of the client ID string.

Since there is one client instance, the server should recognize it's
state whether the client is connecting via TCP or RDMA. Same client,
same lease.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.0: Remove cl_ipaddr from non-UCS client ID

It is possible for two distinct clients to have the same cl_ipaddr:

- if the client admin disables callback with clientaddr=0.0.0.0 on
more than one client

- if two clients behind separate NATs use the same private subnet
number

- if the client admin specifies the same address via clientaddr=
mount option (pointing the server at the same NAT box, for
example)

Because of the way the Linux NFSv4.0 client constructs its client
ID string by default, such clients could interfere with each others'
lease state when mounting the same server:

scnprintf(str, len, "Linux NFSv4.0 %s/%s %s",
clp->cl_ipaddr,
rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR),
rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_PROTO));

cl_ipaddr is set to the value of the clientaddr= mount option. Two
clients whose addresses are 192.168.3.77 that mount the same server
(whose public IP address is, say, 3.4.5.6) would both generate the
same client ID string when sending a SETCLIENTID:

Linux NFSv4.0 192.168.3.77/3.4.5.6 tcp

and thus the server would not be able to distinguish the clients'
leases. If both clients are using AUTH_SYS when sending SETCLIENTID
then the server could possibly permit the two clients to interfere
with or purge each others' leases.

To better ensure that Linux's NFSv4.0 client ID strings are distinct
in these cases, remove cl_ipaddr from the client ID string and
replace it with something more likely to be unique. Note that the
replacement looks a lot like the uniform client ID string.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix a compiler warning when CONFIG_NFS_V4_1 is undefined

Fix a compiler warning:
fs/nfs/nfs4proc.c:910:13: warning: 'nfs4_layoutget_release' defined but not used [-Wunused-function]
static void nfs4_layoutget_release(void *calldata)
^~~~~~~~~~~~~~~~~~~~~~

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Ignore NFS_INO_REVAL_FORCED in nfs4_proc_access

If we hold a delegation, we don't need to care about whether or not
the inode attributes are up to date. We know we can cache the results
of this call regardless.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Don't ask for delegated attributes when adding a hard link

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Don't ask for delegated attributes when revalidating the inode

Again, when revalidating the inode, we don't need to ask for attributes
for which we are authoritative.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Pass the inode down to the getattr() callback

Allow the getattr() callback to check things like whether or not we hold
a delegation so that it can adjust the attributes that it is asking for.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Don't request size+change attribute if they are delegated to us

When we hold a delegation, we should not need to request attributes such
as the file size or the change attribute. For some servers, avoiding
asking for these unneeded attributes can improve the overall system
performance.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

pnfs: Don't release the sequence slot until we've processed layoutget on open

If the server recalls the layout that was just handed out, we risk hitting
a race as described in RFC5661 Section 2.10.6.3 unless we ensure that we
release the sequence slot after processing the LAYOUTGET operation that
was sent as part of the OPEN compound.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

pnfs: Fix manipulation of NFS_LAYOUT_FIRST_LAYOUTGET

The flag was not always being cleared after LAYOUTGET on OPEN.

Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

pnfs: Stop attempting LAYOUTGET on OPEN on failure

Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

pNFS: Refactor nfs4_layoutget_release()

Move the actual freeing of the struct nfs4_layoutget into fs/nfs/pnfs.c
where it can be reused by the layoutget on open code.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

pnfs: Add LAYOUTGET to OPEN of a new file

This triggers when have no pre-existing inode to attach to.
The preexisting case is saved for later.

Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

pnfs: Move nfs4_opendata into nfs4_fs.h

It will be needed now by the pnfs code.

Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

pnfs: Add conditional encode/decode of LAYOUTGET within OPEN compound

Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

pnfs: move allocations out of nfs4_proc_layoutget

They work better in the new alloc_init function.

Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS4: move ctx into nfs4_run_open_task

Preparing to add conditional LAYOUTGET to OPEN rpc, the LAYOUTGET
will need the ctx info.

Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

pnfs: Remove redundant assignment from nfs4_proc_layoutget().

nfs_init_sequence() will clear this for us.

Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Don't add a new lock on an interrupted wait for LOCK

If the wait for a LOCK operation is interrupted, and then the file is
closed, the locks cleanup code will assume that no new locks will be added
to the inode after it has completed. We already have a mechanism to detect
if there was signal, so let's use that to avoid recreating the local lock
once the RPC completes. Also skip re-sending the LOCK operation for the
various error cases if we were signaled.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
[Trond: Fix inverted test of locks_lock_inode_wait()]
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Always clear the pNFS layout when handling ESTALE

If we get an ESTALE error in response to an RPC call operating on the
file on the MDS, we should immediately cancel the layout for that file.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Ensure we revalidate the inode correctly after setacl

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix sillyrename to return the delegation when appropriate

Ensure that we pass down the inode of the file being deleted so
that we can return any delegation being held.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Only pass the delegation to setattr if we're sending a truncate

Even then it isn't really necessary. The reason why we may not want to
pass in a stateid in other cases is that we cannot use the delegation
credential.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Merge nfs41_free_stateid() with _nfs41_free_stateid()

Having these exist as two functions doesn't seem to add anything useful,
and I think merging them together makes this easier to follow.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Pass "privileged" value to nfs4_init_sequence()

We currently have a separate function just to set this, but I think it
makes more sense to set it at the same time as the other values in
nfs4_init_sequence()

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Move call to nfs4_state_protect() to nfs4_commit_setup()

Rather than doing this in the generic NFS client code. Let's put this
with the other v4 stuff so it's all in one place.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Move call to nfs4_state_protect_write() to nfs4_write_setup()

This doesn't really need to be in the generic NFS client code, and I
think it makes more sense to keep the v4 code in one place.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.1: Fix exclusive create

When we use EXCLUSIVE4_1 mode, the server returns an attribute mask where
all the bits indicate which attributes were set, and where the verifier
was stored. In order to figure out which attribute we have to resend,
we need to clear out the attributes that are set in exclcreat_bitmask.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
[Anna: Fixed typo NFS4_CREATE_EXCLUSIVE4 -> NFS4_CREATE_EXCLUSIVE]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix the nfs_inode_set_delegation() arguments

Neither nfs_inode_set_delegation() nor nfs_inode_reclaim_delegation() are
generic code. They have no business delving into NFSv4 OPEN xdr structures,
so let's replace the "struct nfs_openres" parameter.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Don't ask for attributes when ACCESS is protected by a delegation

If we hold a delegation, then the results of the ACCESS call are protected
anyway.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: More fine grained attribute tracking

Currently, if the NFS_INO_INVALID_ATTR flag is set, for instance by
a call to nfs_post_op_update_inode_locked(), then it will not be cleared
until all the attributes have been revalidated. This means, for instance,
that NFSv4 writes will always force a full attribute revalidation.

Track the ctime, mtime, size and change attribute separately from the
other attributes so that we can have nfs_post_op_update_inode_locked()
set them correctly, and later have the cache consistency bitmask be
able to clear them.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Don't return the delegation when not needed by NFSv4.x (x>0)

Starting with NFSv4.1, the server is able to deduce the client id from
the SEQUENCE op which means it can always figure out whether or not
the client is holding a delegation on a file that is being changed.
For that reason, RFC5661 does not require a delegation to be unconditionally
recalled on operations such as SETATTR, RENAME, or REMOVE.

Note that for now, we continue to return READ delegations since that is
still expected by the Linux knfsd server.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Remove the unused return_delegation() callback

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Move the delegation return down into _nfs4_do_setattr()

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add a delegation return into nfs4_proc_unlink_setup()

Ensure that when we do finally delete the file, then we return the
delegation.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Move delegation recall into the NFSv4 callback for rename_setup()

Move the delegation recall out of the generic code, and into the NFSv4
specific callback.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Move the delegation return down into nfs4_proc_remove()

Move the delegation return out of generic code and down into the
NFSv4 specific unlink code.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Move the delegation return down into nfs4_proc_link()

Move the delegation return out of generic code.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix nfs4_return_incompatible_delegation

The 'fmode' argument can take an FMODE_EXEC value, which we want to
filter out before comparing to the delegation type.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs4: wake any lock waiters on successful RECLAIM_COMPLETE

If we have a RECLAIM_COMPLETE with a populated cl_lock_waitq, then
that implies that a reconnect has occurred. Since we can't expect a
CB_NOTIFY_LOCK callback at that point, just wake up the entire queue
so that all the tasks can re-poll for their locks.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs4: don't compare clientid in nfs4_wake_lock_waiter

The task is expected to sleep for a while here, and it's possible that
a new EXCHANGE_ID has occurred in the interim, and we were assigned a
new clientid. Since this is a per-client list, there isn't a lot of
value in vetting the clientid on the incoming request.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs4: always reset notified flag to false before repolling for lock

We may get a notification and lose the race to another client. Ensure
that we wait again for a notification in that case.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs: convert to new i_version API

For NFS, we just use the "raw" API since the i_version is mostly
managed by the server. The exception there is when the client
holds a write delegation, but we only need to bump it once
there anyway to handle CB_GETATTR.

Tested-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

NFSv4: always set NFS_LOCK_LOST when a lock is lost.

There are 2 comments in the NFSv4 code which suggest that
SIGLOST should possibly be sent to a process. In these
cases a lock has been lost.
The current practice is to set NFS_LOCK_LOST so that
read/write returns EIO when a lock is lost.
So change these comments to code when sets NFS_LOCK_LOST.

One case is when lock recovery after apparent server restart
fails with NFS4ERR_DENIED, NFS4ERR_RECLAIM_BAD, or
NFS4ERRO_RECLAIM_CONFLICT. The other case is when a lock
attempt as part of lease recovery fails with NFS4ERR_DENIED.

In an ideal world, these should not happen. However I have
a packet trace showing an NFSv4.1 session getting
NFS4ERR_BADSESSION after an extended network parition. The
NFSv4.1 client treats this like server reboot until/unless
it get NFS4ERR_NO_GRACE, in which case it switches over to
"nograce" recovery mode. In this network trace, the client
attempts to recover a lock and the server (incorrectly)
reports NFS4ERR_DENIED rather than NFS4ERR_NO_GRACE. This
leads to the ineffective comment and the client then
continues to write using the OPEN stateid.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Convert LOCKU to use nfs4_async_handle_exception()

Convert CLOSE so that it specifies the correct stateid and
inode for the error handling.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Convert DELEGRETURN to use nfs4_handle_exception()

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Convert CLOSE to use nfs4_async_handle_exception()

Convert CLOSE so that it specifies the correct stateid, state and
inode for the error handling.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: Revert "NFS: Move the flock open mode check into nfs_flock()"

Commit e12937279c8b "NFS: Move the flock open mode check into nfs_flock()"
changed NFSv3 behavior for flock() such that the open mode must match the
lock type, however that requirement shouldn't be enforced for flock().

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Cc: stable@vger.kernel.org # v4.12
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs: Fix ugly referral attributes

Before traversing a referral and performing a mount, the mounted-on
directory looks strange:

dr-xr-xr-x. 2 4294967294 4294967294 0 Dec 31 1969 dir.0

nfs4_get_referral is wiping out any cached attributes with what was
returned via GETATTR(fs_locations), but the bit mask for that
operation does not request any file attributes.

Retrieve owner and timestamp information so that the memcpy in
nfs4_get_referral fills in more attributes.

Changes since v1:
- Don't request attributes that the client unconditionally replaces
- Request only MOUNTED_ON_FILEID or FILEID attribute, not both
- encode_fs_locations() doesn't use the third bitmask word

Fixes: 6b97fd3da1ea ("NFSv4: Follow a referral")
Suggested-by: Pradeep Thomas <pradeepthomas@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: nfs_set_open_stateid must not trigger state recovery for closed state

In nfs_set_open_stateid_locked, we must ignore stateids from closed state.

Reported-by: Andrew W Elble <aweits@rit.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Clean up nfs4_delegreturn_done

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: cleanup nfs4_close_done

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Retry NFS4ERR_OLD_STATEID errors in layoutreturn

If our layoutreturn returns an NFS4ERR_OLD_STATEID, then try to
update the stateid and retry.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

pNFS: Retry NFS4ERR_OLD_STATEID errors in layoutreturn-on-close

If our layoutreturn on close operation returns an NFS4ERR_OLD_STATEID,
then try to update the stateid and retry. We know that there should
be no further LAYOUTGET requests being launched.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Don't try to CLOSE if the stateid 'other' field has changed

If the stateid is no longer recognised on the server, either due to a
restart, or due to a competing CLOSE call, then we do not have to
retry. Any open contexts that triggered a reopen of the file, will
also act as triggers for any CLOSE for the updated stateids.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Retry CLOSE and DELEGRETURN on NFS4ERR_OLD_STATEID.

If we're racing with an OPEN, then retry the operation instead of
declaring it a success.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
[Andrew W Elble: Fix a typo in nfs4_refresh_open_stateid]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix open create exclusive when the server reboots

If the server that does not implement NFSv4.1 persistent session
semantics reboots while we are performing an exclusive create,
then the return value of NFS4ERR_DELAY when we replay the open
during the grace period causes us to lose the verifier.
When the grace period expires, and we present a new verifier,
the server will then correctly reply NFS4ERR_EXIST.

This commit ensures that we always present the same verifier when
replaying the OPEN.

Reported-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Add a tracepoint to document open stateid updates

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix OPEN / CLOSE race

Ben Coddington has noted the following race between OPEN and CLOSE
on a single client.

Process 1 Process 2 Server
========= ========= ======

1) OPEN file
2) OPEN file
3) Process OPEN (1) seqid=1
4) Process OPEN (2) seqid=2
5) Reply OPEN (2)
6) Receive reply (2)
7) new stateid, seqid=2

8) CLOSE file, using
stateid w/ seqid=2
9) Reply OPEN (1)
10( Process CLOSE (8)
11) Reply CLOSE (8)
12) Forget stateid
file closed

13) Receive reply (7)
14) Forget stateid
file closed.

15) Receive reply (1).
16) New stateid seqid=1
is really the same
stateid that was
closed.

IOW: the reply to the first OPEN is delayed. Since "Process 2" does
not wait before closing the file, and it does not cache the closed
stateid, then when the delayed reply is finally received, it is treated
as setting up a new stateid by the client.

The fix is to ensure that the client processes the OPEN and CLOSE calls
in the same order in which the server processed them.

This commit ensures that we examine the seqid of the stateid
returned by OPEN. If it is a new stateid, we assume the seqid
must be equal to the value 1, and that each state transition
increments the seqid value by 1 (See RFC7530, Section 9.1.4.2,
and RFC5661, Section 8.2.2).

If the tracker sees that an OPEN returns with a seqid that is greater
than the cached seqid + 1, then it bumps a flag to ensure that the
caller waits for the RPCs carrying the missing seqids to complete.

Note that there can still be pathologies where the server crashes before
it can even send us the missing seqids. Since the OPEN call is still
holding a slot when it waits here, that could cause the recovery to
stall forever. To avoid that, we time out after a 5 second wait.

Reported-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs, nfs: convert nfs_client.cl_count from atomic_t to refcount_t

atomic_t variables are currently used to implement reference
counters with the following properties:
- counter is initialized to 1 using atomic_set()
- a resource is freed upon counter reaching zero
- once counter reaches zero, its further
increments aren't allowed
- counter schema uses basic atomic operations
(set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable nfs_client.cl_count is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs, nfs: convert nfs4_lock_state.ls_count from atomic_t to refcount_t

atomic_t variables are currently used to implement reference
counters with the following properties:
- counter is initialized to 1 using atomic_set()
- a resource is freed upon counter reaching zero
- once counter reaches zero, its further
increments aren't allowed
- counter schema uses basic atomic operations
(set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable nfs4_lock_state.ls_count is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1: Fix up replays of interrupted requests

If the previous request on a slot was interrupted before it was
processed by the server, then our slot sequence number may be out of whack,
and so we try the next operation using the old sequence number.

The problem with this, is that not all servers check to see that the
client is replaying the same operations as previously when they decide
to go to the replay cache, and so instead of the expected error of
NFS4ERR_SEQ_FALSE_RETRY, we get a replay of the old reply, which could
(if the operations match up) be mistaken by the client for a new reply.

To fix this, we attempt to send a COMPOUND containing only the SEQUENCE op
in order to resync our slot sequence number.

Cc: Olga Kornievskaia <olga.kornievskaia@gmail.com>
[olga.kornievskaia@gmail.com: fix an Oops]
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Don't compare apples to elephants to determine access bits

The NFS_ACCESS_* flags aren't a 1:1 mapping to the MAY_* flags, so
checking for MAY_WHATEVER might have surprising results in
nfs*_proc_access(). Let's simplify this check when determining which
bits to ask for, and do it in a generic place instead of copying code
for each NFS version.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4/pnfs: Fix an infinite layoutget loop

Since we can now use a lock stateid or a delegation stateid, that
differs from the context stateid, we need to change the test in
nfs4_layoutget_handle_exception() to take this into account.

This fixes an infinite layoutget loop in the NFS client whereby
it keeps retrying the initial layoutget using the same broken
stateid.

Fixes: 70d2f7b1ea19b ("pNFS: Use the standard I/O stateid when...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>