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>
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>
Don't send in a layout, instead use the (possibly NULL) inode.
This is needed for LAYOUTGET attached to an OPEN where the inode is not
yet set.
Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
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>
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>
Pull out the alloc/init part for eventual reuse by OPEN.
Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Ensure that we hold a reference to the layout header when processing
the pNFS return-on-close so that the refcount value does not inadvertently
go to zero.
Reported-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.10+
Tested-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Currently when falling back to doing I/O through the MDS (via
pnfs_{read|write}_through_mds), the client frees the nfs_pgio_header
without releasing the reference taken on the dreq
via pnfs_generic_pg_{read|write}pages -> nfs_pgheader_init ->
nfs_direct_pgio_init. It then takes another reference on the dreq via
nfs_generic_pg_pgios -> nfs_pgheader_init -> nfs_direct_pgio_init and
as a result the requester will become stuck in inode_dio_wait. Once
that happens, other processes accessing the inode will become stuck as
well.
Ensure that pnfs_read_through_mds() and pnfs_write_through_mds() clean
up correctly by calling hdr->completion_ops->completion() instead of
calling hdr->release() directly.
This can be reproduced (sometimes) by performing "storage failover
takeover" commands on NetApp filer while doing direct I/O from a client.
This can also be reproduced using SystemTap to simulate a failure while
doing direct I/O from a client (from Dave Wysochanski
<dwysocha@redhat.com>):
stap -v -g -e 'probe module("nfs_layout_nfsv41_files").function("nfs4_fl_prepare_ds").return { $return=NULL; exit(); }'
Suggested-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Fixes: 1ca018d28d ("pNFS: Fix a memory leak when attempted pnfs fails")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
PNFS block/SCSI layouts should gracefully handle cases where block devices
are not available when a layout is retrieved, or the block devices are
removed while the client holds a layout.
While setting up a layout segment, keep a record of an unavailable or
un-parsable block device in cache with a flag so that subsequent layouts do
not spam the server with GETDEVINFO. We can reuse the current
NFS_DEVICEID_UNAVAILABLE handling with one variation: instead of reusing
the device, we will discard it and send a fresh GETDEVINFO after the
timeout, since the lookup and validation of the device occurs within the
GETDEVINFO response handling.
A lookup of a layout segment that references an unavailable device will
return a segment with the NFS_LSEG_UNAVAILABLE flag set. This will allow
the pgio layer to mark the layout with the appropriate fail bit, which
forces subsequent IO to the MDS, and prevents spamming the server with
LAYOUTGET, LAYOUTRETURN.
Finally, when IO to a block device fails, look up the block device(s)
referenced by the pgio header, and mark them as unavailable.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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>
Bool initializations should use true and false. Bool tests don't need
comparisons.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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 pnfs_layout_hdr.plh_refcount 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>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Instead of having a private method for copying the open/delegation stateid,
use the same call that is used for standard I/O through the MDS.
Note that this means we transmit the stateid with a zero seqid, avoiding
issues with NFS4ERR_OLD_STATEID.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The writeback code wants to send a commit after processing the pages,
which is why we want to delay releasing the struct path until after
that's done.
Also, the layout code expects that we do not free the inode before
we've put the layout segments in pnfs_writehdr_free() and
pnfs_readhdr_free()
Fixes: 919e3bd9a8 ("NFS: Ensure we commit after writeback is complete")
Fixes: 4714fb51fd ("nfs: remove pgio_header refcount, related cleanup")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Now that we no longer hold the inode->i_lock when manipulating the
commit lists, it is safe to call pnfs_put_lseg() again.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
It's possible and acceptable for NFS to attempt to add requests beyond the
range of the current pgio->pg_lseg, a case which should be caught and
limited by the pg_test operation. However, the current handling of this
case replaces pgio->pg_lseg with a new layout segment (after a WARN) within
that pg_test operation. That will cause all the previously added requests
to be submitted with this new layout segment, which may not be valid for
those requests.
Fix this problem by only returning zero for the number of bytes to coalesce
from pg_test for this case which allows any previously added requests to
complete on the current layout segment. The check for requests starting
out of range of the layout segment moves to pg_init, so that the
replacement of pgio->pg_lseg will be done when the next request is added.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Consider the following deadlock:
Process P1 Process P2 Process P3
========== ========== ==========
lock_page(page)
lseg = pnfs_update_layout(inode)
lo = NFS_I(inode)->layout
pnfs_error_mark_layout_for_return(lo)
lock_page(page)
lseg = pnfs_update_layout(inode)
In this scenario,
- P1 has declared the layout to be in error, but P2 holds a reference to
a layout segment on that inode, so the layoutreturn is deferred.
- P2 is waiting for a page lock held by P3.
- P3 is asking for a new layout segment, but is blocked waiting
for the layoutreturn.
The fix is to ensure that pnfs_error_mark_layout_for_return() does
not set the NFS_LAYOUT_RETURN flag, which blocks P3. Instead, we allow
the latter to call LAYOUTGET so that it can make progress and unblock
P2.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
In pnfs_clear_layoutreturn_info, ensure that we don't clear the layout
return info if there are new segments queued for return due to, for
instance, a race between a LAYOUTRETURN and a failed I/O attempt.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If the layout is being invalidated on the server, then we must
invoke nfs_commit_inode() to ensure any commits to the DS get
cleared out.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If the attempt to write through pNFS fails, we need to use the same
failure semantics as for the read path: If the FF_FLAGS_NO_IO_THRU_MDS
flag is set or we have sufficient valid DSes, then we must retry through
pNFS
Fixes: d67ae825a5 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
pnfs_error_mark_layout_for_return needs to check that the layout is
valid before calling pnfs_set_plh_return_info().
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The assumption should be that if the caller returns PNFS_ATTEMPTED, then hdr
has been consumed, and so we should not be testing hdr->task.tk_status.
If the caller returns PNFS_TRY_AGAIN, then we need to recoalesce and
free hdr.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If we have a layout segment cached in pgio->pg_lseg, we should check it
for validity before reusing it in a new RPC request. Otherwise, if we
recoalesce, we can end up looping forever.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
IF NFS_LAYOUT_RETURN_REQUESTED is not set, then we currently exit
without freeing the list of invalidated layout segments, leading
to a reference leak.
Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 24408f5282 ("pNFS: Fix bugs in _pnfs_return_layout")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If the client holds no more writeable open state, and does not hold a
write delegation, then send a layoutreturn as part of the OPEN_DOWNGRADE.
We do this only for writes, since some layout drivers may require you to
also hold a read layout if you are doing a R/W workload.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Ensure we release the NFS_LAYOUT_RETURN lock when we invalidate the
layout stateid, so that processes and RPC tasks that are waiting on
the layout return can continue.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Add a callback to allow the flexfiles layout driver to initialise the
layout private payload.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cleanup to allow layout drivers to attach private data to layoutreturn,
and manage the data.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Ensure that the layout state bits are synced when we cache a layout
segment for layoutreturn using an appropriate call to
pnfs_set_plh_return_info.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
We need to honour the NFS_LAYOUT_RETURN_REQUESTED bit regardless of
whether or not there are layout segments pending.
Furthermore, we should ensure that we leave the plh_return_segs list
empty.
This patch fixes a memory leak of the layout segments on plh_return_segs.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
When the layout state is invalidated, then so is the layout segment
state, and hence we do need to clean up the state bits.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Amend the pnfs return on close helper functions to enable sending the
layoutreturn op in CLOSE/DELEGRETURN. This closes a potential race between
CLOSE/DELEGRETURN and parallel OPEN calls to the same file, and allows the
client and the server to agree on whether or not there is an outstanding
layout.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The layoutreturn call will take care of invalidating the layout segments
once the call is successful.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
There is no change to the value of NFS_LAYOUT_RETURN, so we should
not be waking up the RPC call.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Fix a potential race with CB_LAYOUTRECALL in which the server recalls the
remaining layout segments while our LAYOUTRETURN is still in transit.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
We may want to process and transmit layout stat information for the
layout segments that are being returned, so we should defer freeing
them until after the layoutreturn has completed.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Both pnfs.c and the flexfiles code have their own versions of the
range intersection testing, and the "end_offset" helper.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
We must put the task to sleep while holding the inode->i_lock in order
to ensure atomicity with the test for NFS_LAYOUT_RETURN.
Fixes: 500d701f33 ("NFS41: make close wait for layoutreturn")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If there is an I/O error, we should not call LAYOUTGET until the
LAYOUTRETURN that reports the error is complete.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.8+
If the server sends us a completely new stateid, and the client thinks
it already holds a layout, then force a retry of the LAYOUTGET after
invalidating the existing layout in order to avoid corruption due to
races.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
We must ensure that we don't schedule a layoutreturn if the layout stateid
has been marked as invalid.
Fixes: 2a59a04116 ("pNFS: Fix pnfs_set_layout_stateid() to clear...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.8+
If we no longer hold any layout segments, we're normally expected to
consider the layout stateid to be invalid. However we cannot assume this
if we're about to, or in the process of sending a layoutreturn.
Fixes: 334a8f3711 ("pNFS: Don't forget the layout stateid if...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.8+
We must not call nfs_pageio_init_read() on a new nfs_pageio_descriptor
while holding a reference to a layout segment, as that can deadlock
pnfs_update_layout().
Fixes: d67ae825a5 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.0+
We used to check for a valid layout type id before verifying pNFS flags
as an indicator for if we are using pNFS. This changed in 3132e49ece
with the introduction of multiple layout types, since now we are passing
an array of ids instead of just one. Since then, users have been seeing
a KERN_ERR printk show up whenever mounting NFS v4 without pNFS. This
patch restores the original behavior of exiting set_pnfs_layoutdriver()
early if we aren't using pNFS.
Fixes 3132e49ece ("pnfs: track multiple layout types in fsinfo
structure")
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Fix the code so that we always mark the atime as invalid in nfs4_read_done().
Currently, the expectation appears to be that the pNFS drivers should always
do this, with the result that most of them don't.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Currently, the layout driver selection code always chooses the first one
from the list. That's not really ideal however, as the server can send
the list of layout types in any order that it likes. It's up to the
client to select the best one for its needs.
This patch adds an ordered list of preferred driver types and has the
selection code sort the list of available layout drivers according to it.
Any unrecognized layout type is sorted to the end of the list.
For now, the order of preference is hardcoded, but it should be possible
to make this configurable in the future.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Current NFSv4.1/pNFS client assumes that MDS supports only one layout
type. While it's true for most existing servers, nevertheless, this can
be change in the near future.
For now, this patch just plumbs in the ability to track a list of
layouts in the fsinfo structure. The existing behavior of the client
is preserved, by having it just select the first entry in the list.
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Reviewed-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If there are outstanding LAYOUTGET rpc calls, then we want to ensure that
we keep the layout stateid around so we that don't inadvertently pick up
an old/misordered sequence id.
The race is as follows:
Client Server
====== ======
LAYOUTGET(seqid)
LAYOUTGET(seqid)
return LAYOUTGET(seqid+1)
return LAYOUTGET(seqid+2)
process LAYOUTGET(seqid+2)
forget layout
process LAYOUTGET(seqid+1)
If it forgets the layout stateid before processing seqid+1, then
the client will not check the layout->plh_barrier, and so will set
the stateid with seqid+1.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If the layout was marked as invalid, we want to ensure to initialise
the layout header fields correctly.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
According to RFC5661, the client is responsible for serialising
LAYOUTGET and LAYOUTRETURN to avoid ambiguity. Consider the case
where we send both in parallel.
Client Server
====== ======
LAYOUTGET(seqid=X)
LAYOUTRETURN(seqid=X)
LAYOUTGET return seqid=X+1
LAYOUTRETURN return seqid=X+2
Process LAYOUTRETURN
Forget layout stateid
Process LAYOUTGET
Set seqid=X+1
The client processes the layoutget/layoutreturn in the wrong order,
and since the result of the layoutreturn was to clear the only
existing layout segment, the client forgets the layout stateid.
When the LAYOUTGET comes in, it is treated as having a completely
new stateid, and so the client sets the wrong sequence id...
Fix is to check if there are outstanding LAYOUTGET requests
before we send the LAYOUTRETURN (note that LAYOUGET will already
wait if it sees an outstanding LAYOUTRETURN).
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Ensure that the client conforms to the normative behaviour described in
RFC5661 Section 12.7.2: "If a client believes its lease has expired,
it MUST NOT send I/O to the storage device until it has validated its
lease."
So ensure that we wait for the lease to be validated before using
the layout.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v3.20+
...instead of splitting the initialisation over init_lseg() and
pnfs_layout_process().
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If the server changed the layout stateid's "other" field, then
we should treat the old layout as being completely gone. In that
case, we want to clear the metadata such as scheduled layoutreturns.
Do this by calling pnfs_mark_layout_stateid_invalid().
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
When determining which layout segments to return, we do want
pnfs_mark_matching_lsegs_return to check that they match the layout
sequence id. This ensures that we don't waste time if the server
is replaying a layout recall that has already been satisfied.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
In cases where we need to send a layoutreturn in order to propagate
an error, we should not tie that to a specific layout stateid.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
When we return NFS_OK to the CB_LAYOUTRECALL, we are required to
send a layoutreturn that "completes" that layout recall request, using
the correct stateid.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Currently, pnfs_set_layout_stateid() will update the layout sequence
id barrier only if the stateid itself is newer than the current
layout stateid. However in a situation where multiple LAYOUTGET calls
and a LAYOUTRETURN raced, it is entirely possible for one of the
LAYOUTGET to set the current stateid to something newer than the
LAYOUTRETURN that needs to set the barrier.
The fix is to allow the "update_barrier" flag to force a check as to
whether or not the barrier needs to be updated.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If the layout stateid is invalid, then pnfs_set_layout_stateid() must
always initialise it.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Ensure that we don't carry over layoutreturn info from a previous
incarnation of this layout.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Instead of giving up altogether and falling back to doing I/O
through the MDS, which may make the situation worse, wait for
2 lease periods for the callback to resolve itself, and then
try destroying the existing layout.
Only if this was an attempt at getting a first layout, do we
give up altogether, as the server is clearly crazy.
Fixes: 183d9e7b11 ("pnfs: rework LAYOUTGET retry handling")
Cc: stable@vger.kernel.org # 4.7
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
They are not the same error, and need to be handled differently.
Fixes: 183d9e7b11 ("pnfs: rework LAYOUTGET retry handling")
Cc: stable@vger.kernel.org # 4.7
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
The non-retry error path is currently broken and ends up releasing the
reference to the layout twice. It also can end up clearing the
NFS_LAYOUT_FIRST_LAYOUTGET flag twice, causing a race.
In addition, the retry path will fail to decrement the plh_outstanding
counter.
Fixes: 183d9e7b11 ("pnfs: rework LAYOUTGET retry handling")
Cc: stable@vger.kernel.org # 4.7
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
So ensure that we mark the layout for commit once the write is done,
and then ensure that the commit to ds is finished before sending
layoutcommit.
Note that by doing this, we're able to optimise away the commit
for the case of servers that don't need layoutcommit in order to
return updated attributes.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
According to RFC5661, section 12.5.3. the layout stateid is no longer
valid once the client no longer holds any layout segments. Ensure that
we mark it invalid.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
As flexfiles has FF_FLAGS_NO_READ_IO, there is a need to generically
support enforcing that a IOMODE_RW segment will not allow READ I/O.
Signed-off-by: Tom Haynes <loghyr@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
It can return NULL if layoutgets are blocked currently. Fix it to return
-EAGAIN in that case, so we can properly handle it in pnfs_update_layout.
Also, clean up and simplify the error handling -- eliminate "status" and
just use "lseg".
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
There are several problems in the way a stateid is selected for a
LAYOUTGET operation:
We pick a stateid to use in the RPC prepare op, but that makes
it difficult to serialize LAYOUTGETs that use the open stateid. That
serialization is done in pnfs_update_layout, which occurs well before
the rpc_prepare operation.
Between those two events, the i_lock is dropped and reacquired.
pnfs_update_layout can find that the list has lsegs in it and not do any
serialization, but then later pnfs_choose_layoutget_stateid ends up
choosing the open stateid.
This patch changes the client to select the stateid to use in the
LAYOUTGET earlier, when we're searching for a usable layout segment.
This way we can do it all while holding the i_lock the first time, and
ensure that we serialize any LAYOUTGET call that uses a non-layout
stateid.
This also means a rework of how LAYOUTGET replies are handled, as we
must now get the latest stateid if we want to retransmit in response
to a retryable error.
Most of those errors boil down to the fact that the layout state has
changed in some fashion. Thus, what we really want to do is to re-search
for a layout when it fails with a retryable error, so that we can avoid
reissuing the RPC at all if possible.
While the LAYOUTGET RPC is async, the initiating thread always waits for
it to complete, so it's effectively synchronous anyway. Currently, when
we need to retry a LAYOUTGET because of an error, we drive that retry
via the rpc state machine.
This means that once the call has been submitted, it runs until it
completes. So, we must move the error handling for this RPC out of the
rpc_call_done operation and into the caller.
In order to handle errors like NFS4ERR_DELAY properly, we must also
pass a pointer to the sliding timeout, which is now moved to the stack
in pnfs_update_layout.
The complicating errors are -NFS4ERR_RECALLCONFLICT and
-NFS4ERR_LAYOUTTRYLATER, as those involve a timeout after which we give
up and return NULL back to the caller. So, there is some special
handling for those errors to ensure that the layers driving the retries
can handle that appropriately.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If we get back something like NFS4ERR_OLD_STATEID, that will be
translated into -EAGAIN, and the do/while loop in send_layoutget
will drive the call again.
This is not quite what we want, I think. An error like that is a
sign that something has changed. That something could have been a
concurrent LAYOUTGET that would give us a usable lseg.
Lift the retry logic into pnfs_update_layout instead. That allows
us to redo the layout search, and may spare us from having to issue
an RPC.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Currently, the code will clear the fail bit if we get back a fatal
error. I don't think that's correct -- we want to clear that bit
if we do not get a fatal error.
Fixes: 0bcbf039f6 (nfs: handle request add failure properly)
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
LAYOUTRETURN is "special" in that servers and clients are expected to
work with old stateids. When the client sends a LAYOUTRETURN with an old
stateid in it then the server is expected to only tear down layout
segments that were present when that seqid was current. Ensure that the
client handles its accounting accordingly.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When we want to selectively do a LAYOUTRETURN, we need to specify a
stateid that represents most recent layout acquisition that is to be
returned.
When we mark a layout stateid to be returned, we update the return
sequence number in the layout header with that value, if it's newer
than the existing one. Then, when we go to do a LAYOUTRETURN on
layout header put, we overwrite the seqid in the stateid with the
saved one, and then zero it out.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
In later patches, we're going to teach the client to be more selective
about how it returns layouts. This means keeping a record of what the
stateid's seqid was at the time that the server handed out a layout
segment.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Like other resend paths, mark the (old) hdr as NFS_IOHDR_REDO. This
ensures the hdr completion function will not count the (old) hdr
as good bytes.
Also, vector the error back through the hdr->task.tk_status like other
retry calls.
This fixes a bug with the FlexFiles layout where libaio was reporting more
bytes read than requested.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace another case where the layout 'plh_block_lgets' can trigger
infinite loops in send_layoutget().
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If the server reboots while there is a layoutget outstanding, then
the call to pnfs_choose_layoutget_stateid() will fail with an EAGAIN
error, which causes an infinite loop in send_layoutget(). The reason
why we never break out of the loop is that the layout 'plh_block_lgets'
field is never cleared.
Fix is to replace plh_block_lgets with NFS_LAYOUT_INVALID_STID, which
can be reset after a new layoutget.
Fixes: ab7d763e47 ("pNFS: Ensure nfs4_layoutget_prepare returns...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
When setting the layout return mode, we must always also set the
NFS_LAYOUT_RETURN_REQUESTED flag to ensure that we send a layoutreturn.
Otherwise pnfs_error_mark_layout_for_return() could set the mode, but
fail to send the layoutreturn because another is already in flight.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
We don't need to schedule a layoutreturn if the layout segment can
be freed immediately.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS_LAYOUT_RETURN_BEFORE_CLOSE is being used to signal that a
layoutreturn is needed, either due to a layout recall or to a
layout error. Rename it to NFS_LAYOUT_RETURN_REQUESTED in order
to clarify its purpose.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The layoutreturn code currently relies on pnfs_put_lseg() to initiate the
RPC call when conditions are right. A problem arises when we want to
free the layout segment from inside an inode->i_lock section (e.g. in
pnfs_clear_request_commit()), since we cannot sleep.
The workaround is to move the actual call to pnfs_send_layoutreturn()
to pnfs_put_layout_hdr(), which doesn't have this restriction.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* pnfs_generic:
NFSv4.1/pNFS: Cleanup constify struct pnfs_layout_range arguments
NFSv4.1/pnfs: Cleanup copying of pnfs_layout_range structures
NFSv4.1/pNFS: Cleanup pnfs_mark_matching_lsegs_invalid()
NFSv4.1/pNFS: Fix a race in initiate_file_draining()
NFSv4.1/pNFS: pnfs_error_mark_layout_for_return() must always return layout
NFSv4.1/pNFS: pnfs_mark_matching_lsegs_return() should set the iomode
NFSv4.1/pNFS: Use nfs4_stateid_copy for copying stateids
NFSv4.1/pNFS: Don't pass stateids by value to pnfs_send_layoutreturn()
NFS: Relax requirements in nfs_flush_incompatible
NFSv4.1/pNFS: Don't queue up a new commit if the layout segment is invalid
NFS: Allow multiple commit requests in flight per file
NFS/pNFS: Fix up pNFS write reschedule layering violations and bugs
NFSv4: List stateid information in the callback tracepoints
NFSv4.1/pNFS: Don't return NFS4ERR_DELAY unnecessarily in CB_LAYOUTRECALL
NFSv4.1/pNFS: Ensure we enforce RFC5661 Section 12.5.5.2.1
pNFS: If we have to delay the layout callback, mark the layout for return
NFSv4.1/pNFS: Add a helper to mark the layout as returned
pNFS: Ensure nfs4_layoutget_prepare returns the correct error
