Loopback (file backed by some other file on disk) is an important
use-case, and FUSE features such as passthrough and splicing aim to
reduce overhead.

Example: 

    Splice disabled:

    $ go test -bench FD -test.cpu=1,2
    goos: linux
    goarch: amd64
    pkg: github.com/hanwen/go-fuse/v2/benchmark
    cpu: Intel(R) Core(TM) i5-8350U CPU @ 1.70GHz
    BenchmarkGoFuseFDRead     	    1929	    597942 ns/op	3507.28 MB/s	    4290 B/op	     129 allocs/op
    BenchmarkGoFuseFDRead-2   	    2497	    421856 ns/op	4971.26 MB/s	   62500 B/op	     177 allocs/op
    PASS
    ok  	github.com/hanwen/go-fuse/v2/benchmark	3.510s

    Splice enabled:

    $ go test -bench FD -test.cpu=1,2
    goos: linux
    goarch: amd64
    pkg: github.com/hanwen/go-fuse/v2/benchmark
    cpu: Intel(R) Core(TM) i5-8350U CPU @ 1.70GHz
    BenchmarkGoFuseFDRead     	    1524	    750249 ns/op	2795.28 MB/s	    4132 B/op	      98 allocs/op
    BenchmarkGoFuseFDRead-2   	    2364	    463522 ns/op	4524.39 MB/s	   11719 B/op	     106 allocs/op
    PASS

in other words, the API complexity that splicing introduced was not
worth it: it actually slows down things.

Change-Id: I4f7519ab2cc5b0145d0f7f81f55ad20d544e9d87

Change-Id: I683c0f614f67e787229d0754354a25f225184995

Change-Id: Iad80862a8d13cb03511a005d385735594ff5e353

The passthrough feature lets a filesystem register an open file
descriptor with the kernel to avoid roundtrips for read/write
operations.

Change-Id: Ia8bde502a3450028f4d87ba61fa9c76ea3ea6c63

Change-Id: I18bde502a3450028f4d87ba61fa9c76ea3ea6c63

Document why some bits are platform dependent.

Change-Id: Ib8bde502a3450028f4d87ba61fa9c76ea3ea6c63

Add definitions and print routines for FUSE_NO_EXPORT_SUPPORT,
FUSE_NOTIFY_RESEND and FOPEN_PASSTHROUGH and associated fields.

Change-Id: I5bd52c44a91484ac78ea5413cbd4bf5dc927501e

Change-Id: I331f9f702fa0a850df2d6f1e3dd75f9f550750ed

Multiple reader code was introduced in
03081e9d (May 2012). Redo the
benchmark to verify that this still makes sense.

Change-Id: I03432b93285d3e3e9494858c844be1ff2dbd3147

This enables using go-fuse in a init binary that is spawned directly from
the kernel.

See also https://github.com/hanwen/go-fuse/pull/525.

Change-Id: Ibbaa04af993677536bd4ae8a173a5a6d93118940

mips64 uses 0x4000 for LARGEFILE. See also issue #514	

Change-Id: I46e83824f412131961318b16767bc05273fa2fbe

Add `isTest` to avoid panicking outside of test scenarios, in case we
mess up the flag definitions. The latter can easily happen, due to
subtle differences between architectures.

Change-Id: I4085de49e39eddf328269a7a3e694818c693e195

This will allow duplicate keys in the initialization.

Change-Id: I16969bddd1aad0232477379229a0afbe8faf1933

gvfsd-trash sets an inotify watch on mntDir and stat()s every file that is
created, racing with the test logic.

Create our files in a subdir to avoid that, as gvfsd-trash does not monitor
subdirs.

Fixes: https://github.com/hanwen/go-fuse/issues/478
Change-Id: I8e297a16af7fdd8b8c9574d456bbf43d36eddd67

It is sometimes helpful to know which process accesses
the filesystem.

Relates-to: https://github.com/hanwen/go-fuse/issues/478
Change-Id: Ie435d093f03a32c02f02b45df880a207c5d7cad1

Change-Id: I8f05010f64edaf1d41fdfca31ee4ae3079cd0ae3

As of commit 4f621f9a, we don't
support older versions

Change-Id: I9f05010f64edaf1d41fdfca31ee4ae3079cd0ae3

Change-Id: Ib094e7e55f922780408223626d88388d2cc5f8b6

Use UtimesNanoAt with AT_SYMLINK_NOFOLLOW. Add
PosixTest/SetattrSymlink to test this.

Change-Id: Ia3a00ad75afd1ba255965025f63fd047662885ec

posix_fallocate(2) returns error directly without setting errno[1]

[1]: https://man.freebsd.org/cgi/man.cgi?query=posix_fallocate&sektion=2

Change-Id: I90ac60ecab6f8814a579cc96d11d4d6660408e88

This test case is going to test whether the file lock works well on the
system. It firstly adds a lock and then get the lock through syscalls.
It uses F_OFD_GETLK command of fcntl(2) to get the lock info on an
opened file description[1], which is not defined on the FreeBSD. This
commit seperate the process of getting the information of lock for
different OSes, and mimic the behaviour of F_OFD_GETLK on FreeBSD.

[1]: https://www.gnu.org/software/libc/manual/html_node/Open-File-Description-Locks.html

Change-Id: I8abae0e7040fc667143eea028731e341be9b1baf

Fails to compile.
Example: https://github.com/hanwen/go-fuse/actions/runs/8909081785/job/24465823082

	Run GOMAXPROCS="1" ./all.bash
	+ go build ./...
	go: downloading golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a
	Error: fs/api.go:237:2: //go:build comment without // +build comment
	Error: fs/api.go:237:2: //go:build comment without // +build comment
	Error: Process completed with exit code 1.

Change-Id: I2e396906d9cf9fa2248b04f3963b1b2d32b6fd57

Calling Serve() multiple times leads to a panic on unmount and fun
debugging sessions ( https://github.com/hanwen/go-fuse/issues/512 ).
Catch it early.

Change-Id: I3c490448fa3b8407a6db1bd8ad94b8a4e1a93828

Per default, only 1000 FUSE mounts are allowed, then you get
> /usr/bin/fusermount3: too many FUSE filesystems mounted; mount_max=N can be set in /etc/fuse.conf

Let's stay well below 1000 as there may be other (unrelated)
FUSE mounts also occupying slots.

Change-Id: I2e2e094a88236ff803abba3722395c29207c8571

Change-Id: Iffa5314fbe171d182a4bdef42e0ab4781cc1d221

Prefer x/sys/unix over syscall package, which supports FreeBSD.

Change-Id: Ifd3a0fd6d2b90369a6e1e74d92606a655815a6a4

Change-Id: Ib1e1e1054db73df031e4be958206fc94bbea1236

test

Change-Id: Idcb3ee99c1afdde410e41e3a67c29c3143f602c3

Change-Id: Ifb01913d17650e0fa729888f64cd2fe2017dfe1f

Change-Id: I214834639a835b61db2fc0d283ffabb948535ff5

Change-Id: I8ff8e8dc9431b5af52e3ca8e78f0da73cead9008

Change-Id: Ibc41b9efc62f89359e712def53b1cfc1dd4c24fc

Both FreeBSD and Darwin must use a single reader to access the FUSE device.

Change-Id: I51c467bb0b8e1fda871665d033dd89d11fbe961c

fuse: merge attr definition of Darwin and FreeBSD

Change-Id: I7229229aed8afad74089bc2ce7eff0b86bd2ccd0

Change-Id: I7caa793f1b7a2c3601094ca46e1a3812e763e813

Change-Id: I76715678a305ebe981ba20392965ff5c011b883e

Change-Id: I2b80c97a8b7bd4e93085ba6fe4a0bf2a852db78e

Change-Id: I694fa828c6f71941412afbb46535eb40dbecb4b2

Thanks to https://github.com/likeazir for spotting this

Change-Id: I0952482886cfadb23c723d89a64fd4ced1b57c92

This avoids spurious error messages when unmounting a file system
directly after closing a file.

Fixes #505

Change-Id: I3a6a6ada0b5e5abe95a1d7965a48ddb46664310a