NFS: Clean up generic writeback tracepoints

Clean up the generic writeback tracepoints so they do pass the
full structures as arguments. Also ensure we report the number
of bytes act

NFS: Clean up generic writeback tracepoints

Clean up the generic writeback tracepoints so they do pass the
full structures as arguments. Also ensure we report the number
of bytes actually written.

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

show more ...

NFS: Clean up generic file read tracepoints

Clean up the generic file read tracepoints so they do pass the
full structures as arguments. Also ensure we report the number
of bytes act

NFS: Clean up generic file read tracepoints

Clean up the generic file read tracepoints so they do pass the
full structures as arguments. Also ensure we report the number
of bytes actually read.

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

show more ...

NFS: Introduce trace events triggered by page writeback errors

Try to capture the reason for the writeback path tagging an error on
a page.

Signed-off-by: Chuck Lever <chuck.lev

NFS: Introduce trace events triggered by page writeback errors

Try to capture the reason for the writeback path tagging an error on
a page.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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reimplement path_mountpoint() with less magic

... and get rid of a bunch of bugs in it. Background:
the reason for path_mountpoint() is that umount() really doesn't
want attempts to

reimplement path_mountpoint() with less magic

... and get rid of a bunch of bugs in it. Background:
the reason for path_mountpoint() is that umount() really doesn't
want attempts to revalidate the root of what it's trying to umount.
The thing we want to avoid actually happen from complete_walk();
solution was to do something parallel to normal path_lookupat()
and it both went overboard and got the boilerplate subtly
(and not so subtly) wrong.

A better solution is to do pretty much what the normal path_lookupat()
does, but instead of complete_walk() do unlazy_walk(). All it takes
to avoid that ->d_weak_revalidate() call... mountpoint_last() goes
away, along with everything it got wrong, and so does the magic around
LOOKUP_NO_REVAL.

Another source of bugs is that when we traverse mounts at the final
location (and we need to do that - umount . expects to get whatever's
overmounting ., if any, out of the lookup) we really ought to take
care of ->d_manage() - as it is, manual umount of autofs automount
in progress can lead to unpleasant surprises for the daemon. Easily
solved by using handle_lookup_down() instead of follow_mount().

Tested-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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NFS: Add a tracepoint in nfs_fh_to_dentry()

Add a tracepoint in nfs_fh_to_dentry() for debugging issues with bad
userspace filehandles.

Signed-off-by: Trond Myklebust <trond.myk

NFS: Add a tracepoint in nfs_fh_to_dentry()

Add a tracepoint in nfs_fh_to_dentry() for debugging issues with bad
userspace filehandles.

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

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kill LOOKUP_NO_EVAL, don't bother including namei.h from audit.h

The former has no users left; the latter was only to get LOOKUP_...
values to remapper in audit_inode() and that's an ex-

kill LOOKUP_NO_EVAL, don't bother including namei.h from audit.h

The former has no users left; the latter was only to get LOOKUP_...
values to remapper in audit_inode() and that's an ex-parrot now.

All places that use symbols from namei.h include it either directly
or (in a few cases) via a local header, like fs/autofs/autofs_i.h

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

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NFS: Record task, client ID, and XID in xdr_status trace points

When triggering an nfs_xdr_status trace point, record the task ID
and XID of the failing RPC to better pinpoint the proble

NFS: Record task, client ID, and XID in xdr_status trace points

When triggering an nfs_xdr_status trace point, record the task ID
and XID of the failing RPC to better pinpoint the problem.

This feels like a bit of a layering violation.

Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFS: Update symbolic flags displayed by trace events

Add missing symbolic flag names and display flags variables in
hexadecimal to improve observability.

Signed-off-by: Chuck Le

NFS: Update symbolic flags displayed by trace events

Add missing symbolic flag names and display flags variables in
hexadecimal to improve observability.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFS: Display symbolic status code names in trace log

For improved readability, add nfs_show_status() call-sites in the
generic NFS trace points so that the symbolic status code name is

NFS: Display symbolic status code names in trace log

For improved readability, add nfs_show_status() call-sites in the
generic NFS trace points so that the symbolic status code name is
displayed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFS: Add trace events to report non-zero NFS status codes

These can help field troubleshooting without needing the overhead
of a full network capture (ie, tcpdump).

Signed-off-b

NFS: Add trace events to report non-zero NFS status codes

These can help field troubleshooting without needing the overhead
of a full network capture (ie, tcpdump).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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Merge tag 'nfs-for-4.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
"Highlights include:

Stable bugfixes:

Merge tag 'nfs-for-4.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
"Highlights include:

Stable bugfixes:

- Fix breakages in the nfsstat utility due to the inclusion of the
NFSv4 LOOKUPP operation

- Fix a NULL pointer dereference in nfs_idmap_prepare_pipe_upcall()
due to nfs_idmap_legacy_upcall() being called without an 'aux'
parameter

- Fix a refcount leak in the standard O_DIRECT error path

- Fix a refcount leak in the pNFS O_DIRECT fallback to MDS path

- Fix CPU latency issues with nfs_commit_release_pages()

- Fix the LAYOUTUNAVAILABLE error case in the file layout type

- NFS: Fix a race between mmap() and O_DIRECT

Features:

- Support the statx() mask and query flags to enable optimisations
when the user is requesting only attributes that are already up to
date in the inode cache, or is specifying the AT_STATX_DONT_SYNC
flag

- Add a module alias for the SCSI pNFS layout type

Bugfixes:

- Automounting when resolving a NFSv4 referral should preserve the
RDMA transport protocol settings

- Various other RDMA bugfixes from Chuck

- pNFS block layout fixes

- Always set NFS_LOCK_LOST when a lock is lost"

* tag 'nfs-for-4.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (69 commits)
NFS: Fix a race between mmap() and O_DIRECT
NFS: Remove a redundant call to unmap_mapping_range()
pnfs/blocklayout: Ensure disk address in block device map
pnfs/blocklayout: pnfs_block_dev_map uses bytes, not sectors
lockd: Fix server refcounting
SUNRPC: Fix null rpc_clnt dereference in rpc_task_queued tracepoint
SUNRPC: Micro-optimize __rpc_execute
SUNRPC: task_run_action should display tk_callback
sunrpc: Format RPC events consistently for display
SUNRPC: Trace xprt_timer events
xprtrdma: Correct some documenting comments
xprtrdma: Fix "bytes registered" accounting
xprtrdma: Instrument allocation/release of rpcrdma_req/rep objects
xprtrdma: Add trace points to instrument QP and CQ access upcalls
xprtrdma: Add trace points in the client-side backchannel code paths
xprtrdma: Add trace points for connect events
xprtrdma: Add trace points to instrument MR allocation and recovery
xprtrdma: Add trace points to instrument memory invalidation
xprtrdma: Add trace points in reply decoder path
xprtrdma: Add trace points to instrument memory registration
..

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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 delegat

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>

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nfs: Use proper enum definitions for nfs_show_stable

Commit 8224b2734ab1 ("NFS: Add static NFS I/O tracepoints") had a
hack to work around some odd behavior observed with
__print_sym

nfs: Use proper enum definitions for nfs_show_stable

Commit 8224b2734ab1 ("NFS: Add static NFS I/O tracepoints") had a
hack to work around some odd behavior observed with
__print_symbolic. I couldn't ever get it to display NFS_FILE_SYNC
when using TRACE_DEFINE_ENUM macros to set up the enum values.

I tracked down the actual bug that forced me to add the workaround.
That issue will be addressed soon, so replace the hack with a proper
implementation.

Fixes: 8224b2734ab1 ("NFS: Add static NFS I/O tracepoints")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

NFS: Add static NFS I/O tracepoints

Tools like tcpdump and rpcdebug can be very useful. But there are
plenty of environments where they are difficult or impossible to
use. For exampl

NFS: Add static NFS I/O tracepoints

Tools like tcpdump and rpcdebug can be very useful. But there are
plenty of environments where they are difficult or impossible to
use. For example, we've had customers report I/O failures during
workloads so heavy that collecting network traffic or enabling
RPC debugging are themselves onerous.

The kernel's static tracepoints are lightweight (less likely to
introduce timing changes) and efficient (the trace data is compact).
They also work in scenarios where capturing network traffic is not
possible due to lack of hardware support (some InfiniBand HCAs) or
where data or network privacy is a concern.

Introduce tracepoints that show when an NFS READ, WRITE, or COMMIT
is initiated, and when it completes. Record the arguments and
results of each operation, which are not shown by existing sunrpc
module's tracepoints.

For instance, the recorded offset and count can be used to match an
"initiate" event to a "done" event. If an NFS READ result returns
fewer bytes than requested or zero, seeing the EOF flag can be
probative. Seeing an NFS4ERR_BAD_STATEID result is also indication
of a particular class of problems. The timing information attached
to each event record can often be useful as well.

Usage example:

[root@manet tmp]# trace-cmd record -e nfs:*initiate* -e nfs:*done
/sys/kernel/debug/tracing/events/nfs/*initiate*/filter
/sys/kernel/debug/tracing/events/nfs/*done/filter
Hit Ctrl^C to stop recording
^CKernel buffer statistics:
Note: "entries" are the entries left in the kernel ring buffer and are not
recorded in the trace data. They should all be zero.

CPU: 0
entries: 0
overrun: 0
commit overrun: 0
bytes: 3680
oldest event ts: 78.367422
now ts: 100.124419
dropped events: 0
read events: 74

... and so on.

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

show more ...

Merge tag 'nfs-for-4.8-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
"Highlights include:

Stable bugfixes:
- n

Merge tag 'nfs-for-4.8-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
"Highlights include:

Stable bugfixes:
- nfs: don't create zero-length requests

- several LAYOUTGET bugfixes

Features:
- several performance related features

- more aggressive caching when we can rely on close-to-open
cache consistency

- remove serialisation of O_DIRECT reads and writes

- optimise several code paths to not flush to disk unnecessarily.

However allow for the idiosyncracies of pNFS for those layout
types that need to issue a LAYOUTCOMMIT before the metadata can
be updated on the server.

- SUNRPC updates to the client data receive path

- pNFS/SCSI support RH/Fedora dm-mpath device nodes

- pNFS files/flexfiles can now use unprivileged ports when
the generic NFS mount options allow it.

Bugfixes:
- Don't use RDMA direct data placement together with data
integrity or privacy security flavours

- Remove the RDMA ALLPHYSICAL memory registration mode as
it has potential security holes.

- Several layout recall fixes to improve NFSv4.1 protocol
compliance.

- Fix an Oops in the pNFS files and flexfiles connection
setup to the DS

- Allow retry of operations that used a returned delegation
stateid

- Don't mark the inode as revalidated if a LAYOUTCOMMIT is
outstanding

- Fix writeback races in nfs4_copy_range() and
nfs42_proc_deallocate()"

* tag 'nfs-for-4.8-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (104 commits)
pNFS: Actively set attributes as invalid if LAYOUTCOMMIT is outstanding
NFSv4: Clean up lookup of SECINFO_NO_NAME
NFSv4.2: Fix warning "variable ‘stateids’ set but not used"
NFSv4: Fix warning "no previous prototype for ‘nfs4_listxattr’"
SUNRPC: Fix a compiler warning in fs/nfs/clnt.c
pNFS: Remove redundant smp_mb() from pnfs_init_lseg()
pNFS: Cleanup - do layout segment initialisation in one place
pNFS: Remove redundant stateid invalidation
pNFS: Remove redundant pnfs_mark_layout_returned_if_empty()
pNFS: Clear the layout metadata if the server changed the layout stateid
pNFS: Cleanup - don't open code pnfs_mark_layout_stateid_invalid()
NFS: pnfs_mark_matching_lsegs_return() should match the layout sequence id
pNFS: Do not set plh_return_seq for non-callback related layoutreturns
pNFS: Ensure layoutreturn acts as a completion for layout callbacks
pNFS: Fix CB_LAYOUTRECALL stateid verification
pNFS: Always update the layout barrier seqid on LAYOUTGET
pNFS: Always update the layout stateid if NFS_LAYOUT_INVALID_STID is set
pNFS: Clear the layout return tracking on layout reinitialisation
pNFS: LAYOUTRETURN should only update the stateid if the layout is valid
nfs: don't create zero-length requests
...

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tracing: Use __get_str() when manipulating strings

Use __get_str(str) rather than __get_dynamic_array(str) when
deadling with strings.

It is just a code cleanup, no changes on t

tracing: Use __get_str() when manipulating strings

Use __get_str(str) rather than __get_dynamic_array(str) when
deadling with strings.

It is just a code cleanup, no changes on tracepoint ABI.

Link: http://lkml.kernel.org/r/ea260df91817411cca2a1f3db2abd88860094788.1467407618.git.bristot@redhat.com

Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-nfs@vger.kernel.org
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

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NFS: Kill NFS_INO_NFS_INO_FLUSHING: it is a performance killer

filemap_datawrite() and friends already deal just fine with livelock.

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

NFS: Kill NFS_INO_NFS_INO_FLUSHING: it is a performance killer

filemap_datawrite() and friends already deal just fine with livelock.

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

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nfs: per-name sillyunlink exclusion

use d_alloc_parallel() for sillyunlink/lookup exclusion and
explicit rwsem (nfs_rmdir() being a writer and nfs_call_unlink() -
a reader) for rmdir

nfs: per-name sillyunlink exclusion

use d_alloc_parallel() for sillyunlink/lookup exclusion and
explicit rwsem (nfs_rmdir() being a writer and nfs_call_unlink() -
a reader) for rmdir/sillyunlink one.

That ought to make lookup/readdir/!O_CREAT atomic_open really
parallel on NFS.

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

show more ...

NFS: Allow multiple commit requests in flight per file

Allow synchronous RPC calls to wait for pending RPC calls to finish,
but also allow asynchronous ones to just fire off another comm

NFS: Allow multiple commit requests in flight per file

Allow synchronous RPC calls to wait for pending RPC calls to finish,
but also allow asynchronous ones to just fire off another commit.

With this patch, the xfstests generic/074 test completes in 226s
instead of 242s

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

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NFS: fix the handling of NFS_INO_INVALID_DATA flag in nfs_revalidate_mapping

There is a possible race in how the nfs_invalidate_mapping function is
handled. Currently, we go and invalid

NFS: fix the handling of NFS_INO_INVALID_DATA flag in nfs_revalidate_mapping

There is a possible race in how the nfs_invalidate_mapping function is
handled. Currently, we go and invalidate the pages in the file and then
clear NFS_INO_INVALID_DATA.

The problem is that it's possible for a stale page to creep into the
mapping after the page was invalidated (i.e., via readahead). If another
writer comes along and sets the flag after that happens but before
invalidate_inode_pages2 returns then we could clear the flag
without the cache having been properly invalidated.

So, we must clear the flag first and then invalidate the pages. Doing
this however, opens another race:

It's possible to have two concurrent read() calls that end up in
nfs_revalidate_mapping at the same time. The first one clears the
NFS_INO_INVALID_DATA flag and then goes to call nfs_invalidate_mapping.

Just before calling that though, the other task races in, checks the
flag and finds it cleared. At that point, it trusts that the mapping is
good and gets the lock on the page, allowing the read() to be satisfied
from the cache even though the data is no longer valid.

These effects are easily manifested by running diotest3 from the LTP
test suite on NFS. That program does a series of DIO writes and buffered
reads. The operations are serialized and page-aligned but the existing
code fails the test since it occasionally allows a read to come out of
the cache incorrectly. While mixing direct and buffered I/O isn't
recommended, I believe it's possible to hit this in other ways that just
use buffered I/O, though that situation is much harder to reproduce.

The problem is that the checking/clearing of that flag and the
invalidation of the mapping really need to be atomic. Fix this by
serializing concurrent invalidations with a bitlock.

At the same time, we also need to allow other places that check
NFS_INO_INVALID_DATA to check whether we might be in the middle of
invalidating the file, so fix up a couple of places that do that
to look for the new NFS_INO_INVALIDATING flag.

Doing this requires us to be careful not to set the bitlock
unnecessarily, so this code only does that if it believes it will
be doing an invalidation.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

show more ...

NFS: Add tracepoints for debugging NFS hard links

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

NFS: Add tracepoints for debugging NFS rename and sillyrename issues

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

NFS: Add tracepoints for debugging directory changes

Add tracepoints for mknod, mkdir, rmdir, remove (unlink) and symlink.

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

NFS: Add tracepoints for debugging generic file create events

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