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>
For the 'files' and 'flexfiles' layout types, we do not expect the reply
to be any larger than 4k. The block and scsi layout types are a little more
greedy, so we keep allocating the maximum response size for now.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If someone interrupts a wait on one or more outstanding layoutgets in
pnfs_update_layout() then return the ERESTARTSYS/EINTR error.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If we knew that the file was empty, we wouldn't be asking for a layout.
Any optimisation here is already done before calling pnfs_update_layout().
As it stands, we sometimes end up doing an unnecessary inband read to
the MDS even when holding a layout.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Yes, it is possible to get trapped in a loop, but the server should be
administratively revoking the recalled layout if it never gets returned.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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>
Return statements in functions returning bool should use true or false
instead of an integer value.
This issue was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Layout segment validity is determined only by the NFS_LSEG_VALID flag. If
it is set, the layout segment is finable. As it is, when the flexfiles
driver sets NFS_LSEG_LAYOUTRETURN to indicate that we cannot discard
the layout segment, but that it must be returned, then this can result
in an unnecessary layoutget storm.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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>
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>
If the old layout was recalled, and we returned NFS4ERR_NOMATCHINGLAYOUT
then we need to wait for all outstanding layoutget calls to complete
before we can send a new one.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If a layout has been recalled, then we should fire off a layoutreturn as
soon as all the layout segments that match the recall have been retired.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If there are layout segments that are marked for return, then we need
to ensure that pnfs_mark_matching_lsegs_return() does not just
silently discard them, but it should tell the caller that there is a
layoutreturn scheduled.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Currently, when IO to DS fails, client returns the layout and
retries against the MDS. However, then on umounting (inode eviction)
it returns the layout again.
This is because pnfs_return_layout() was changed in
commit d78471d32b ("pnfs/blocklayout: set PNFS_LAYOUTRETURN_ON_ERROR")
to always set NFS_LAYOUT_RETURN_REQUESTED so even if we returned
the layout, it will be returned again. Instead, let's also check
if we have already marked the layout invalid.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the layoutget on open call failed, we can't really commit the inode,
so don't bother calling it.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If we're only opening the file for reading, and the file is empty and/or
we already have cached data, then heuristically optimise away the
LAYOUTGET.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Ensure that we only switch off the LAYOUTGET operation in the OPEN
compound when the server is truly broken, and/or it is complaining
that the compound is too large.
Currently, we end up turning off the functionality permanently,
even for transient errors such as EACCES or ENOSPC.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We need to ensure that pnfs_parse_lgopen() doesn't try to parse a
struct nfs4_layoutget_res that was not filled by a successful call
to decode_layoutget(). This can happen if we performed a cached open,
or if either the OP_ACCESS or OP_GETATTR operations preceding the
OP_LAYOUTGET in the compound returned an error.
By initialising the 'status' field to NFS4ERR_DELAY, we ensure that
pnfs_parse_lgopen() won't try to interpret the structure.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
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>
Since the LAYOUTGET on OPEN can be sent without prior inode information,
existing methods to prevent LAYOUTGET from being sent while processing
CB_LAYOUTRECALL don't work. Track if a recall occurred while LAYOUTGET
was being sent, and if so ignore the results.
Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
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>
