fuse

type Connection struct {
	// contains filtered or unexported fields
}

type MountConfig struct {
	// The context from which every op read from the connetion by the sever
	// should inherit. If nil, context.Background() will be used.
	OpContext context.Context

	// If non-empty, the name of the file system as displayed by e.g. `mount`.
	// This is important because the `umount` command requires root privileges if
	// it doesn't agree with /etc/fstab.
	FSName string

	// Mount the file system in read-only mode. File modes will appear as normal,
	// but opening a file for writing and metadata operations like chmod,
	// chtimes, etc. will fail.
	ReadOnly bool

	// A logger to use for logging errors. All errors are logged, with the
	// exception of a few blacklisted errors that are expected. If nil, no error
	// logging is performed.
	ErrorLogger *log.Logger

	// A logger to use for logging debug information. If nil, no debug logging is
	// performed.
	DebugLogger *log.Logger

	// Linux only. OS X always behaves as if writeback caching is disabled.
	//
	// By default on Linux we allow the kernel to perform writeback caching
	// (cf. http://goo.gl/LdZzo1):
	//
	// *   When the user calls write(2), the kernel sticks the user's data into
	//     its page cache. Only later does it call through to the file system,
	//     potentially after coalescing multiple small user writes.
	//
	// *   The file system may receive multiple write ops from the kernel
	//     concurrently if there is a lot of page cache data to flush.
	//
	// *   Write performance may be significantly improved due to the user and
	//     the kernel not waiting for serial round trips to the file system. This
	//     is especially true if the user makes tiny writes.
	//
	// *   close(2) (and anything else calling f_op->flush) causes all dirty
	//     pages to be written out before it proceeds to send a FlushFileOp
	//     (cf. https://goo.gl/TMrY6X).
	//
	// *   Similarly, close(2) causes the kernel to send a setattr request
	//     filling in the mtime if any dirty pages were flushed, since the time
	//     at which the pages were written to the file system can't be trusted.
	//
	// *   close(2) (and anything else calling f_op->flush) writes out all dirty
	//     pages, then sends a setattr request with an appropriate mtime for
	//     those writes if there were any, and only then proceeds to send a
	//     flush.
	//
	//     Code walk:
	//
	//     *   (https://goo.gl/zTIZQ9) fuse_flush calls write_inode_now before
	//         calling the file system. The latter eventually calls into
	//         __writeback_single_inode.
	//
	//     *   (https://goo.gl/L7Z2w5) __writeback_single_inode calls
	//         do_writepages, which writes out any dirty pages.
	//
	//     *   (https://goo.gl/DOPgla) __writeback_single_inode later calls
	//         write_inode, which calls into the superblock op struct's write_inode
	//         member. For fuse, this is fuse_write_inode
	//         (cf. https://goo.gl/eDSKOX).
	//
	//     *   (https://goo.gl/PbkGA1) fuse_write_inode calls fuse_flush_times.
	//
	//     *   (https://goo.gl/ig8x9V) fuse_flush_times sends a setttr request
	//         for setting the inode's mtime.
	//
	// However, this brings along some caveats:
	//
	// *   The file system must handle SetInodeAttributesOp or close(2) will fail,
	//     due to the call chain into fuse_flush_times listed above.
	//
	// *   The kernel caches mtime and ctime regardless of whether the file
	//     system tells it to do so, disregarding the result of further getattr
	//     requests (cf. https://goo.gl/3ZZMUw, https://goo.gl/7WtQUp). It
	//     appears this may be true of the file size, too. Writeback caching may
	//     therefore not be suitable for file systems where these attributes can
	//     spontaneously change for reasons the kernel doesn't observe. See
	//     http://goo.gl/V5WQCN for more discussion.
	//
	// Setting DisableWritebackCaching disables this behavior. Instead the file
	// system is called one or more times for each write(2), and the user's
	// syscall doesn't return until the file system returns.
	DisableWritebackCaching bool

	// OS X only.
	//
	// Normally on OS X we mount with the novncache option
	// (cf. http://goo.gl/1pTjuk), which disables entry caching in the kernel.
	// This is because osxfuse does not honor the entry expiration values we
	// return to it, instead caching potentially forever (cf.
	// http://goo.gl/8yR0Ie), and it is probably better to fail to cache than to
	// cache for too long, since the latter is more likely to hide consistency
	// bugs that are difficult to detect and diagnose.
	//
	// This field disables the use of novncache, restoring entry caching. Beware:
	// the value of ChildInodeEntry.EntryExpiration is ignored by the kernel, and
	// entries will be cached for an arbitrarily long time.
	EnableVnodeCaching bool

	// Linux only.
	//
	// Linux 4.20 introduced caching symlink targets in the page cache:
	// https://github.com/torvalds/linux/commit/5571f1e65486be025f73fa6aa30fb03725d362a2
	//
	// This is not enabled by default because the old behavior masked a bug:
	// file systems could return any size in the inode attributes of
	// symlinks. After enabling caching, the specified size caps the symlink
	// target.
	EnableSymlinkCaching bool

	// Linux only.
	//
	// Tell the kernel to treat returning -ENOSYS on OpenFile as not needing
	// OpenFile calls at all (Linux >= 3.16):
	EnableNoOpenSupport bool

	// Linux only.
	//
	// Tell the kernel to treat returning -ENOSYS on OpenDir as not needing
	// OpenDir calls at all (Linux >= 5.1):
	EnableNoOpendirSupport bool

	// Disable FUSE default permissions.
	// This is useful for situations where the backing data store (e.g., S3) doesn't
	// actually utilise any form of qualifiable UNIX permissions.
	DisableDefaultPermissions bool

	// Use vectored reads.
	// Vectored read allows file systems to avoid memory copying overhead if
	// the data is already in memory when they return it to FUSE.
	// When turned on, ReadFileOp.Dst is always nil and the FS must return data
	// being read from the file as a list of slices in ReadFileOp.Data.
	UseVectoredRead bool

	// OS X only.
	//
	// The name of the mounted volume, as displayed in the Finder. If empty, a
	// default name involving the string 'osxfuse' is used.
	VolumeName string

	// Additional key=value options to pass unadulterated to the underlying mount
	// command. See `man 8 mount`, the fuse documentation, etc. for
	// system-specific information.
	//
	// For expert use only! May invalidate other guarantees made in the
	// documentation for this package.
	Options map[string]string

	// Sets the filesystem type (third field in /etc/mtab). /etc/mtab and
	// /proc/mounts will show the filesystem type as fuse.<Subtype>.
	// If not set, /proc/mounts will show the filesystem type as fuse/fuseblk.
	Subtype string

	// Flag to enable async reads that are received from
	// the kernel
	EnableAsyncReads bool
}

type MountedFileSystem struct {
	// contains filtered or unexported fields
}

type Notifier struct {
	// contains filtered or unexported fields
}

type Server interface {
	// Read and serve ops from the supplied connection until EOF. Do not return
	// until all operations have been responded to. Must not be called more than
	// once.
	ServeOps(*Connection)
}