The current mirrored read failover code is correctly resetting the mirror
index between failed reads, however it is not able to actually flip the
RPC call over to the next RPC client.
The end result is that we keep resending the RPC call to the same client
over and over.
The fix is to use the pnfs_read_resend_pnfs() mechanism to schedule a
new RPC call, but we need to add the ability to pass in a mirror
index so that we always retry the next mirror in the list.
Fixes: 166bd5b889 ("pNFS/flexfiles: Fix layoutstats handling during read failovers")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Make sure we specify the layout segment range when calculating the
mirror count. In theory, that number could depend on the range to
which we're writing.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Both nfs_pageio_reset_read_mds() and nfs_pageio_reset_write_mds()
do call pnfs_generic_pg_cleanup() for us.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the mirror count changes in the new layout we pick up inside
ff_layout_pg_init_write(), then we can end up adding the
request to the wrong mirror and corrupting the mirror->pg_list.
Fixes: d600ad1f2b ("NFS41: pop some layoutget errors to application")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Move from requesting only full file layout segments, to requesting
layout segments that match our I/O size. This means the server is
still free to return a full file layout, but we will no longer
error out if it does not.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
When starting to read or write with a layout segment, check that the
range matches our request.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Check that the number of mirrors, and the mirror information matches
before deciding to merge layout segments in pNFS/flexfiles.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Move the pNFS commit related operations into a separate structure
that can be carried by the pnfs_ds_commit_info.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Enable adding and lookup of per-layout segment commits in filelayout
and flexfilelayout.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Ensure that both the file and flexfiles layout types clean up when
freeing the layout segments.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
When we have multiple layout segments with different lists of mirrored
data, we need to track the commits on a per layout segment basis.
This patch adds a list to support this tracking in struct
pnfs_ds_commit_info.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Just allocate the array at the end of the layout segment structure,
instead of allocating it as a separate array of pointers.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Ensure that if the DS is returning too many DELAY and GRACE errors, we
also report that to the MDS through the layouterror mechanism.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the attempt to do pNFS fails, then record what action we
take to recover (resend, reset to pnfs or reset to mds).
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If the mount is hard, we should ignore the 'io_maxretrans' module
parameter so that we always keep retrying.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This reverts commit a79f194aa4.
The mechanism for aborting I/O is racy, since we are not guaranteed that
the request is asleep while we're changing both task->tk_status and
task->tk_action.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v5.1
Add tracepoints to allow debugging of the event chain leading to
a pnfs fallback to doing I/O through the MDS.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a helper for when we remove the explicit pointer to the open
context.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When the client is reading or writing using pNFS, and hits an error
on the DS, then it typically sends a LAYOUTERROR and/or LAYOUTRETURN
to the MDS, before redirtying the failed pages, and going for a new
round of reads/writebacks. The problem is that if the server has no
way to fix the DS, then we may need a way to interrupt this loop
after a set number of attempts have been made.
This patch adds an optional module parameter that allows the admin
to specify how many times to retry the read/writeback process before
failing with a fatal error.
The default behaviour is to retry forever.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
During a read failover, we may end up changing the value of
the pgio_mirror_idx, so make sure that we record the layout
stats before that update.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Pass in a pointer to the mirror rather than having to retrieve it from
the array and then verify the resulting pointer.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If we notice that a DS may be down, we should attempt to read from the
other mirrors first before we go back to retry the dead DS.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
While we may want to skip attempting to connect to a downed mirror
when we're deciding which mirror to select for a read, we do not
want to do so once we've committed to attempting the I/O in
ff_layout_read/write_pagelist(), or ff_layout_initiate_commit()
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
When a read to the preferred mirror returns an error, the flexfiles
driver records the error in the inode list and currently marks the
layout for return before failing over the attempted read to the next
mirror.
What we actually want to do is fire off a LAYOUTERROR to notify the
MDS that there is an issue with the preferred mirror, then we fail
over. Only once we've failed to read from all mirrors should we
return the layout.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If a layout segment gets invalidated while a pNFS I/O operation
is queued for transmission, then we ideally want to abort
immediately. This is particularly the case when there is a large
number of I/O related RPCs queued in the RPC layer, and the layout
segment gets invalidated due to an ENOSPC error, or an EACCES (because
the client was fenced). We may end up forced to spam the MDS with a
lot of otherwise unnecessary LAYOUTERRORs after that I/O fails.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Having access to the controlling rpc_rqst means a trace point in the
XDR code can report:
- the XID
- the task ID and client ID
- the p_name of RPC being processed
Subsequent patches will introduce such trace points.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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>
We can use cred->groupinfo (from the 'struct cred') instead.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The SUNRPC credential framework was put together before
Linux has 'struct cred'. Now that we have it, it makes sense to
use it.
This first step just includes a suitable 'struct cred *' pointer
in every 'struct auth_cred' and almost every 'struct rpc_cred'.
The rpc_cred used for auth_null has a NULL 'struct cred *' as nothing
else really makes sense.
For rpc_cred, the pointer is reference counted.
For auth_cred it isn't. struct auth_cred are either allocated on
the stack, in which case the thread owns a reference to the auth,
or are part of 'struct generic_cred' in which case gc_base owns the
reference, and "acred" shares it.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Since commit bb21ce0ad2 we always enforce per-mirror stateid.
However, this makes sense only for v4+ servers.
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
rfc8435 says:
For tight coupling, ffds_stateid provides the stateid to be used by
the client to access the file.
However current implementation replaces per-mirror provided stateid with
by open or lock stateid.
Ensure that per-mirror stateid is used by ff_layout_write_prepare_v4 and
nfs4_ff_layout_prepare_ds.
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Rick Macklem <rmacklem@uoguelph.ca>
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 we get an error while retrieving the layout, then we should
report it rather than falling back to I/O through the MDS.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If a layout segment is carrying layoutstats or layout error information,
then we always want to return it rather than using a forgetful model.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Hightlights include:
Bugfixes:
- Fix an rcu deadlock in nfs_delegation_find_inode()
- Fix NFSv4 deadlocks due to not freeing the session slot in layoutget
- Don't send layoutreturn if the layout is already invalid
- Prevent duplicate XID allocation
- flexfiles: Don't tie up all the rpciod threads in resends
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Merge tag 'nfs-for-4.18-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
"Hightlights include:
- fix an rcu deadlock in nfs_delegation_find_inode()
- fix NFSv4 deadlocks due to not freeing the session slot in
layoutget
- don't send layoutreturn if the layout is already invalid
- prevent duplicate XID allocation
- flexfiles: Don't tie up all the rpciod threads in resends"
* tag 'nfs-for-4.18-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
pNFS/flexfiles: Process writeback resends from nfsiod context as well
pNFS/flexfiles: Don't tie up all the rpciod threads in resends
sunrpc: Prevent duplicate XID allocation
pNFS: Don't send layoutreturn if the layout is already invalid
pNFS: Always free the session slot on error in nfs4_layoutget_handle_exception
NFS: Fix an rcu deadlock in nfs_delegation_find_inode()
Although the writeback resends are more robust than the reads, since they
are not immediately rescheduled by the same thread, we are better off
processing them in the same place as the reads.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We do not want to have rpciod threads perform recursive calls into the
RPC layer since that can deadlock. In particular, having to wait for
a layoutget can be nasty... We want rather to defer scheduling those
retries until we're in the rpc_release() callback, since that is
called from the nfsiod workqueue.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
