NFS: Clean up nfs_sillyrename()

Optimise for the case where we only do one lookup.
Clean up the code so it is obvious that silly[] is not a dynamic array.

Signed-off-by: Trond M

NFS: Clean up nfs_sillyrename()

Optimise for the case where we only do one lookup.
Clean up the code so it is obvious that silly[] is not a dynamic array.

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

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helper for reading ->d_count

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

NFS: Don't allow NFS silly-renamed files to be deleted, no signal

Commit 73ca100 broke the code that prevents the client from deleting
a silly renamed dentry. This affected "delete on l

NFS: Don't allow NFS silly-renamed files to be deleted, no signal

Commit 73ca100 broke the code that prevents the client from deleting
a silly renamed dentry. This affected "delete on last close"
semantics as after that commit, nothing prevented removal of
silly-renamed files. As a result, a process holding a file open
could easily get an ESTALE on the file in a directory where some
other process issued 'rm -rf some_dir_containing_the_file' twice.
Before the commit, any attempt at unlinking silly renamed files would
fail inside may_delete() with -EBUSY because of the
DCACHE_NFSFS_RENAMED flag. The following testcase demonstrates
the problem:
tail -f /nfsmnt/dir/file &
rm -rf /nfsmnt/dir
rm -rf /nfsmnt/dir
# second removal does not fail, 'tail' process receives ESTALE

The problem with the above commit is that it unhashes the old and
new dentries from the lookup path, even in the normal case when
a signal is not encountered and it would have been safe to call
d_move. Unfortunately the old dentry has the special
DCACHE_NFSFS_RENAMED flag set on it. Unhashing has the
side-effect that future lookups call d_alloc(), allocating a new
dentry without the special flag for any silly-renamed files. As a
result, subsequent calls to unlink silly renamed files do not fail
but allow the removal to go through. This will result in ESTALE
errors for any other process doing operations on the file.

To fix this, go back to using d_move on success.
For the signal case, it's unclear what we may safely do beyond d_drop.

Reported-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org

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nfs: remove kfree() redundant null checks

smatch analysis:

fs/nfs/getroot.c:130 nfs_get_root() info: redundant null
check on name calling kfree()

fs/nfs/unlink.c:272 n

nfs: remove kfree() redundant null checks

smatch analysis:

fs/nfs/getroot.c:130 nfs_get_root() info: redundant null
check on name calling kfree()

fs/nfs/unlink.c:272 nfs_async_unlink() info: redundant null
check on devname_garbage calling kfree()

Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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Revert "NFS: add nfs_sb_deactive_async to avoid deadlock"

This reverts commit 324d003b0cd82151adbaecefef57b73f7959a469.

The deadlock turned out to be caused by a workqueue limitatio

Revert "NFS: add nfs_sb_deactive_async to avoid deadlock"

This reverts commit 324d003b0cd82151adbaecefef57b73f7959a469.

The deadlock turned out to be caused by a workqueue limitation that has
now been worked around in the RPC code (see comment in rpc_free_task).

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

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NFS: add nfs_sb_deactive_async to avoid deadlock

Use nfs_sb_deactive_async instead of nfs_sb_deactive when in a workqueue
context. This avoids a deadlock where rpc_shutdown_client loops

NFS: add nfs_sb_deactive_async to avoid deadlock

Use nfs_sb_deactive_async instead of nfs_sb_deactive when in a workqueue
context. This avoids a deadlock where rpc_shutdown_client loops forever
in a workqueue kworker context, trying to kill all RPC tasks associated with
the client, while one or more of these tasks have already been assigned to the
same kworker (and will never run rpc_exit_task).

This approach is needed because RPC tasks that have already been assigned
to a kworker by queue_work cannot be canceled, as explained in the comment
for workqueue.c:insert_wq_barrier.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
[Trond: add module_get/put.]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: Create a return_delegation rpc op

Delegations are a v4 feature, so push return_delegation out of the
generic client by creating a new rpc_op and renaming the old function to
be

NFS: Create a return_delegation rpc op

Delegations are a v4 feature, so push return_delegation out of the
generic client by creating a new rpc_op and renaming the old function to
be in the nfs v4 "namespace"

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

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NFS: Remove nfs4_setup_sequence from generic rename code

This is an NFS v4 specific operation, so it belongs in the NFS v4 code
and not the generic client.

Signed-off-by: Bryan

NFS: Remove nfs4_setup_sequence from generic rename code

This is an NFS v4 specific operation, so it belongs in the NFS v4 code
and not the generic client.

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

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NFS: Remove nfs4_setup_sequence from generic unlink code

This is an NFS v4 specific operation, so it belongs in the NFS v4 code
and not the generic client.

Signed-off-by: Bryan

NFS: Remove nfs4_setup_sequence from generic unlink code

This is an NFS v4 specific operation, so it belongs in the NFS v4 code
and not the generic client.

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

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NFS: Fix a number of sparse warnings

Fix a number of "warning: symbol 'foo' was not declared. Should it be
static?" conditions.

Fix 2 cases of "warning: Using plain integer as N

NFS: Fix a number of sparse warnings

Fix a number of "warning: symbol 'foo' was not declared. Should it be
static?" conditions.

Fix 2 cases of "warning: Using plain integer as NULL pointer"

fs/nfs/delegation.c:263:31: warning: restricted fmode_t degrades to integer
- We want to allow upgrades to a WRITE delegation, but should otherwise
consider servers that hand out duplicate delegations to be borken.

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

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NFSv41: Add a new helper nfs4_init_sequence()

Clean up

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

NFS: Get rid of nfs_restart_rpc()

It can trivially be replaced with rpc_restart_call_prepare.

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

nfs: don't use d_move in nfs_async_rename_done

If the task that initiated the sillyrename ends up being killed by a
fatal signal, then it will eventually return back to userspace and end

nfs: don't use d_move in nfs_async_rename_done

If the task that initiated the sillyrename ends up being killed by a
fatal signal, then it will eventually return back to userspace and end
up releasing the i_mutex. d_move however needs to be done while holding
the i_mutex.

Instead of using d_move here, just unhash the old and new dentries to
prevent them from being found by lookups. With this change though, the
dentries are now incorrect post-rename and do not reflect the actual
name of the file on the server. I'm proceeding under the assumption
that since they are unhashed that this isn't really a problem.

In order for the sillydelete to still work though, the dname must be
copied earlier when setting up the sillydelete info, and the name must
be recopied if the sillydelete info has to be moved to a new dentry.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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nfs: document nfsv4 sillyrename issues

Somebody working on this code asked what the deal was with NFSv4, since
this comment notes that it's v2/v3's statelessness that requires
sillyr

nfs: document nfsv4 sillyrename issues

Somebody working on this code asked what the deal was with NFSv4, since
this comment notes that it's v2/v3's statelessness that requires
sillyrename. Shouldn't hurt to document the answer.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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nfs: store devname at disconnected NFS roots

part 2: make sure that disconnected roots have corresponding mnt_devname
values stashed into them.

Have nfs*_get_root() stuff a copy

nfs: store devname at disconnected NFS roots

part 2: make sure that disconnected roots have corresponding mnt_devname
values stashed into them.

Have nfs*_get_root() stuff a copy of devname into ->d_fsdata of the
found root, provided that it is disconnected.

Have ->d_release() free it when dentry goes away.

Have the places where NFS uses ->d_fsdata for sillyrename (and that
can *never* happen to a disconnected root - dentry will be attached
to its parent) free old devname copies if they find those.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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SUNRPC: Close a race in __rpc_wait_for_completion_task()

Although they run as rpciod background tasks, under normal operation
(i.e. no SIGKILL), functions like nfs_sillyrename(), nfs4_pr

SUNRPC: Close a race in __rpc_wait_for_completion_task()

Although they run as rpciod background tasks, under normal operation
(i.e. no SIGKILL), functions like nfs_sillyrename(), nfs4_proc_unlck()
and nfs4_do_close() want to be fully synchronous. This means that when we
exit, we want all references to the rpc_task to be gone, and we want
any dentry references etc. held by that task to be released.

For this reason these functions call __rpc_wait_for_completion_task(),
followed by rpc_put_task() in the expectation that the latter will be
releasing the last reference to the rpc_task, and thus ensuring that the
callback_ops->rpc_release() has been called synchronously.

This patch fixes a race which exists due to the fact that
rpciod calls rpc_complete_task() (in order to wake up the callers of
__rpc_wait_for_completion_task()) and then subsequently calls
rpc_put_task() without ensuring that these two steps are done atomically.

In order to avoid adding new spin locks, the patch uses the existing
waitqueue spin lock to order the rpc_task reference count releases between
the waiting process and rpciod.
The common case where nobody is waiting for completion is optimised for by
checking if the RPC_TASK_ASYNC flag is cleared and/or if the rpc_task
reference count is 1: in those cases we drop trying to grab the spin lock,
and immediately free up the rpc_task.

Those few processes that need to put the rpc_task from inside an
asynchronous context and that do not care about ordering are given a new
helper: rpc_put_task_async().

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

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Merge branch 'nfs-for-2.6.38' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6

* 'nfs-for-2.6.38' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (89 commits)
NFS fix the setti

Merge branch 'nfs-for-2.6.38' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6

* 'nfs-for-2.6.38' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (89 commits)
NFS fix the setting of exchange id flag
NFS: Don't use vm_map_ram() in readdir
NFSv4: Ensure continued open and lockowner name uniqueness
NFS: Move cl_delegations to the nfs_server struct
NFS: Introduce nfs_detach_delegations()
NFS: Move cl_state_owners and related fields to the nfs_server struct
NFS: Allow walking nfs_client.cl_superblocks list outside client.c
pnfs: layout roc code
pnfs: update nfs4_callback_recallany to handle layouts
pnfs: add CB_LAYOUTRECALL handling
pnfs: CB_LAYOUTRECALL xdr code
pnfs: change lo refcounting to atomic_t
pnfs: check that partial LAYOUTGET return is ignored
pnfs: add layout to client list before sending rpc
pnfs: serialize LAYOUTGET(openstateid)
pnfs: layoutget rpc code cleanup
pnfs: change how lsegs are removed from layout list
pnfs: change layout state seqlock to a spinlock
pnfs: add prefix to struct pnfs_layout_hdr fields
pnfs: add prefix to struct pnfs_layout_segment fields
...

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fs: dcache scale dentry refcount

Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural

fs: dcache scale dentry refcount

Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

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NFSv4: Convert a few commas into semicolons...

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

a couple of open-coded ihold() introduced by nfs merge

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

NFSv4.1: keep seq_res.sr_slot as pointer rather than an index

Having to explicitly initialize sr_slotid to NFS4_MAX_SLOT_TABLE
resulted in numerous bugs. Keeping the current slot as a p

NFSv4.1: keep seq_res.sr_slot as pointer rather than an index

Having to explicitly initialize sr_slotid to NFS4_MAX_SLOT_TABLE
resulted in numerous bugs. Keeping the current slot as a pointer
to the slot table is more straight forward and robust as it's
implicitly set up to NULL wherever the seq_res member is initialized
to zeroes.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: Fix a use-after-free case in nfs_async_rename()

The call to nfs_async_rename_release() after rpc_run_task() is incorrect.
The rpc_run_task() is always guaranteed to call the ->rpc_r

NFS: Fix a use-after-free case in nfs_async_rename()

The call to nfs_async_rename_release() after rpc_run_task() is incorrect.
The rpc_run_task() is always guaranteed to call the ->rpc_release() method.

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

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nfs: make sillyrename an async operation

A synchronous rename can be interrupted by a SIGKILL. If that happens
during a sillyrename operation, it's possible for the rename call to
be

nfs: make sillyrename an async operation

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

Fix this problem by turning sillyrename into an asynchronous operation
and have the task doing the sillyrename just wait on the reply. If the
task is killed before the sillyrename completes, it'll still proceed
to completion.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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nfs: move nfs_sillyrename to unlink.c

...since that's where most of the sillyrenaming code lives. A comment
block is added to the beginning as well to clarify how sillyrenaming
works

nfs: move nfs_sillyrename to unlink.c

...since that's where most of the sillyrenaming code lives. A comment
block is added to the beginning as well to clarify how sillyrenaming
works. Also, make nfs_async_unlink static as nfs_sillyrename is the only
caller.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFSv4.1: Make nfs4_setup_sequence take a nfs_server argument

In anticipation of the day when we have per-filesystem sessions, and also
in order to allow the session to change in the even

NFSv4.1: Make nfs4_setup_sequence take a nfs_server argument

In anticipation of the day when we have per-filesystem sessions, and also
in order to allow the session to change in the event of a filesystem
migration event.

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

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