tests/fusefs: fix all tests that depend on kern.maxphys

The tests try to read kern.maxphys sysctl into int value, while
unsigned long is required. Not sure when this was broken, seems like
since cd8537910406e.

Reviewed by: asomers
Differential Revision: https://reviews.freebsd.org/D45053

fusefs: prefer new/delete over malloc/free

MFC after: 2 weeks
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D43464

fusefs: fix unused variables from fb619c94c67

PR: 270749
Reported by: cy
MFC after: 1 week
MFC with: fb619c94c679e939496fe0cf94b8d2cba95e6e63
Sponsored by: Axcient

fusefs: fix some bugs updating atime during close

When using cached attributes, we must update a file's atime during
close, if it has been read since the last attribute refresh. But,

* Don't update atime if we lack write permissions to the file or if the
file system is readonly.
* If the daemon fails our atime update request for any reason, don't
report this as a failure for VOP_CLOSE.

PR: 270749
Reported by: Jamie Landeg-Jones <jamie@catflap.org>
MFC after: 1 week
Sponsored by: Axcient
Reviewed by: pfg
Differential Revision: https://reviews.freebsd.org/D41925

Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

fusefs tests: handle -Wdeprecated* issues with GoogleTest 1.14.0

`INSTANTIATE_TEST_CASE_P` has been replaced with `INSTANTIATE_TEST_SUITE_P`.
Replace all uses of the former macro with the latter macro.

While here, address the fact that the latter macro doesn't permit some
of the constructions that the former macro did, e.g., empty parameters,
etc.

MFC after: 2 weeks
Reviewed by: asomers
Differential Revision: https://reviews.freebsd.org/D41398

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

[skip ci] fusefs: delete a stray comment from 91972cfcddf

MFC after: 3 days

fusefs: fix 32-bit build of the tests after 91972cfcddf

MFC after: 2 weeks
MFC with: 91972cfcddf950d7a9c33df5a9171ada1805a144

fusefs: update atime on reads when using cached attributes

When using cached attributes, whether or not the data cache is enabled,
fusefs must update a file's atime whenever it reads from it, so long as
it wasn't mounted with -o noatime. Update it in-kernel, and flush it to
the server on close or during the next setattr operation.

The downside is that close() will now frequently trigger a FUSE_SETATTR
upcall. But if you care about performance, you should be using
-o noatime anyway.

MFC after: 2 weeks
Reviewed by: pfg
Differential Revision: https://reviews.freebsd.org/D33145

tests/sys/fs/fusefs/read.cc: fix build on powerpc64

There sig_atomic_t is shorter than void *.
As result, it cannot keep pointer.

Assigning to void * is actually safe for us in a signal handler.

Reviewed by: asomers
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Fixes: 4f917847c9037d
Differential revision: https://reviews.freebsd.org/D32064

fusefs: don't panic if FUSE_GETATTR fails durint VOP_GETPAGES

During VOP_GETPAGES, fusefs needs to determine the file's length, which
could require a FUSE_GETATTR operation. If that fails, it's better to
SIGBUS than panic.

MFC after: 1 week
Sponsored by: Axcient
Reviewed by: markj, kib
Differential Revision: https://reviews.freebsd.org/D31994

fusefs: fix some memory leaks in the tests.

Oddly, most of these were not detected by Coverity.

Reported by: Coverity (one of them, anyway)
Coverity CID: 1404490
MFC after: 2 weeks

fusefs: coverity cleanup in the tests

Address the following defects reported by Coverity:

* Structurally dead code (CID 1404366): set m_quit before FAIL, not after

* Unchecked return value of sysctlbyname (CID 1404321)

* Unchecked return value of stat(2) (CID 1404471)

* Unchecked return value of open(2) (CID 1404402, 1404529)

* Unchecked return value of dup(2) (CID 1404478)

* Buffer overflows. These are all false positives caused by the fact that
Coverity thinks I'm using a buffer to store strings, when in fact I'm
really just using it to store a byte array that happens to be initialized
with a string. I'm changing the type from char to uint8_t in the hopes
that it will placate Coverity. (CID 1404338, 1404350, 1404367, 1404376,
1404379, 1404381, 1404388, 1404403, 1404425, 1404433, 1404434, 1404474,
1404480, 1404484, 1404503, 1404505)

* False positive file descriptor leak. I'm going to try to fix this with
Coverity modeling, but I'll also change an EXPECT to ASSERT so we don't
perform meaningless assertions after the failure. (CID 1404320, 1404324,
1404440, 1404445).

* Unannotated file descriptor leak. This will be followed up by a Coverity
modeling change. (CID 1404326, 1404334, 1404336, 1404357, 1404361,
1404372, 1404391, 1404395, 1404409, 1404430, 1404448, 1404451, 1404455,
1404457, 1404458, 1404460)

* Uninitialized variables in C++ constructors (CID 1404327, 1404346). In the
case of m_maxphys, this actually led to part of the FUSE_INIT's response
being set to stack garbage during the WriteCluster::clustering test.

* Uninitialized sun_len field in struct sockaddr_un (CID 1404330, 1404371,
1404429).

Reported by: Coverity
Reviewed by: emaste
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21457

fusefs: add SVN Keywords to the test files

Reported by: SVN pre-commit hooks
MFC after: 15 days
MFC-With: r350665
Sponsored by: The FreeBSD Foundation

fusefs: skip some tests when unsafe aio is disabled

MFC after: 16 days
MFC-With: r350665
Sponsored by: The FreeBSD Foundation

fusefs: fix warnings in the tests reported by GCC

Sponsored by: The FreeBSD Foundation

sendfile: don't panic when VOP_GETPAGES_ASYNC returns an error

PR: 236466
Sponsored by: The FreeBSD Foundation

fusefs: tighten expectations in mmap tests

In r349378 I fixed mmap's habit of reading more data than was available.

Sponsored by: The FreeBSD Foundation

fusefs: annotate deliberate file descriptor leaks in the tests

closing a file descriptor causes FUSE activity that is superfluous to the
purpose of most tests, but would nonetheless require matching expectations.
Rather than do that, most tests deliberately leak file descriptors instead.
This commit moves the leakage from each test into two trivial functions:
leak and leakdir. Hopefully Coverity will only complain about those
functions and not all of their callers.

Sponsored by: The FreeBSD Foundation

fusefs: implement protocol 7.23's FUSE_WRITEBACK_CACHE option

As of protocol 7.23, fuse file systems can specify their cache behavior on a
per-mountpoint basis. If they set FUSE_WRITEBACK_CACHE in
fuse_init_out.flags, then they'll get the writeback cache. If not, then
they'll get the writethrough cache. If they set FOPEN_DIRECT_IO in every
FUSE_OPEN response, then they'll get no cache at all.

The old vfs.fusefs.data_cache_mode sysctl is ignored for servers that use
protocol 7.23 or later. However, it's retained for older servers,
especially for those running in jails that lack access to the new protocol.

This commit also fixes two other minor test bugs:
* WriteCluster:SetUp was using an uninitialized variable.
* Read.direct_io_pread wasn't verifying that the cache was actually
bypassed.

Sponsored by: The FreeBSD Foundation

fusefs: fix the tests for non-default values of MAXPHYS

Sponsored by: The FreeBSD Foundation

fusefs: fix the tests for nondefault values of vfs.maxbcachebuf

Sponsored by: The FreeBSD Foundation

fusefs: rewrite vop_getpages and vop_putpages

Use the standard facilities for getpages and putpages instead of bespoke
implementations that don't work well with the writeback cache. This has
several corollaries:

* Change the way we handle short reads _again_. vfs_bio_getpages doesn't
provide any way to handle unexpected short reads. Plus, I found some more
lock-order problems. So now when the short read is detected we'll just
clear the vnode's attribute cache, forcing the file size to be requeried
the next time it's needed. VOP_GETPAGES doesn't have any way to indicate
a short read to the "caller", so we just bzero the rest of the page
whenever a short read happens.

* Change the way we decide when to set the FUSE_WRITE_CACHE bit. We now set
it for clustered writes even when the writeback cache is not in use.

Sponsored by: The FreeBSD Foundation

fusefs: correctly handle short reads

A fuse server may return a short read for three reasons:

* The file is opened with FOPEN_DIRECT_IO. In this case, the short read
should be returned directly to userland. We already handled this case
correctly.

* The file was truncated server-side, and the read hit EOF. In this case,
the kernel should update the file size. Fixed in the case of VOP_READ.
Fixing this for VOP_GETPAGES is TODO.

* The file is opened in writeback mode, there are dirty buffers past what
the server thinks is the file's EOF, and the read hit what the server
thinks is the file's EOF. In this case, the client is trying to read a
hole, and should zero-fill it. We already handled this case, and I added
a test for it.

Sponsored by: The FreeBSD Foundation

fusefs: implement VOP_BMAP

If the fuse daemon supports FUSE_BMAP, then use that for the block mapping.
Otherwise, use the same technique used by vop_stdbmap. Report large values
for runp and runb in order to maximize read clustering and minimize upcalls,
even if we don't know the true layout.

The major result of this change is that sequential reads to FUSE files will
now usually happen 128KB at a time instead of 64KB.

Sponsored by: The FreeBSD Foundation

fusefs: use cluster_read for more readahead

fusefs will now use cluster_read. This allows readahead of more than one
cache block. However, it won't yet actually cluster the reads because that
requires VOP_BMAP, which fusefs does not yet implement.

Sponsored by: The FreeBSD Foundation

fusefs: implement non-clustered readahead

fusefs will now read ahead at most one cache block at a time (usually 64
KB). Clustered reads are still TODO. Individual file systems may disable
read ahead by setting fuse_init_out.max_readahead=0 during initialization.

Sponsored by: The FreeBSD Foundation

fusefs: rename the ReadCacheable.default_readahead test

The test didn't actually have anything to do with readahead. Rename it to
"ReadCacheable.cache_block"

Sponsored by: The FreeBSD Foundation

fusefs: make the tests more cplusplusy

* Prefer std::unique_ptr to raw pointers
* Prefer pass-by-reference to pass-by-pointer
* Prefer static_cast to C-style cast, unless it's too much typing

Reported by: ngie
Sponsored by: The FreeBSD Foundation

fusefs: more build fixes

* Fix printf format strings on 32-bit OSes
* Fix -Wclass-memaccess violation on GCC-8 caused by using memset on an object
of non-trivial type.
* Fix memory leak in MockFS::init
* Fix -Wcast-align error on i386 in expect_readdir
* Fix some heterogenous comparison errors on 32-bit OSes.

Sponsored by: The FreeBSD Foundation

fusefs: implement FUSE_ASYNC_READ

If a daemon sets the FUSE_ASYNC_READ flag during initialization, then the
client is allowed to issue multiple concurrent reads for the same file
handle. Otherwise concurrent reads are not allowed. This commit implements
it. Previously we unconditionally disallowed concurrent reads.

Sponsored by: The FreeBSD Foundation

fusefs: Upgrade FUSE protocol to version 7.9.

This commit upgrades the FUSE API to protocol 7.9 and adds unit tests for
backwards compatibility with servers built for version 7.8. It doesn't
implement any of 7.9's new features yet.

Sponsored by: The FreeBSD Foundation

fusefs: shorten and consolidate sleeps

Some fusefs tests must sleep because they deliberately trigger a race, or
because they're testing the cache timeout functionality. Consolidate the
sleep interval in a single place so it will be easy to adjust. Shorten it
from either 500ms or 250ms to 100ms. From experiment I find that 10ms works
every time, so 100ms should be fairly safe.

Sponsored by: The FreeBSD Foundation

fusefs: skip the Read.keep_cache test when cache is disabled

This should've been part of r345892

PR: 236560
Sponsored by: The FreeBSD Foundation

fusefs: cache file attributes

FUSE_LOOKUP, FUSE_GETATTR, FUSE_SETATTR, FUSE_MKDIR, FUSE_LINK,
FUSE_SYMLINK, FUSE_MKNOD, and FUSE_CREATE all return file attributes with a
cache validity period. fusefs will now cache the attributes, if the server
returns a non-zero cache validity period.

This change does _not_ implement finite attr cache timeouts. That will
follow as part of PR 235773.

PR: 235775
Reported by: cem
Sponsored by: The FreeBSD Foundation

fusefs: properly handle FOPEN_KEEP_CACHE

If a fuse file system returne FOPEN_KEEP_CACHE in the open or create
response, then the client is supposed to _not_ clear its caches for that
file. I don't know why clearing the caches would be the default given that
there's a separate flag to bypass the cache altogether, but that's the way
it is. fusefs(5) will now honor this flag.

Our behavior is slightly different than Linux's because we reuse file
handles. That means that open(2) wont't clear the cache if there's a
reusable file handle, even if the file server wouldn't have sent
FOPEN_KEEP_CACHE had we opened a new file handle like Linux does.

PR: 236560
Sponsored by: The FreeBSD Foundation

fusefs: fix more tests when data caching is disabled

readahead is also disallowed when data_cache_mode=0. This should've been
part of r345720.

Sponsored by: The FreeBSD Foundation

fusefs: fix tests when data caching is disabled

VOP_GETPAGES is disabled when vfs.fusefs.data_cache_mode=0, causing mmap to
return success but accessing the mapped memory will subsequently segfault.

Sponsored by: The FreeBSD Foundation

fusefs: adapt the tests to the fuse => fusefs rename

Sponsored by: The FreeBSD Foundation