fs_shell: Support truncate operation in fuse

This allows to copy a file over an existing file

Change-Id: I174751987dcb2f372718e949a8d57b795dc1fd29
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6868
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

bfs_fuse: Allow non-root to mount BFS partitions.

* Most FUSE options are only allowed for root, so don't add these options
when user is not root.
* Fixes ticket #8254.

Signed-off-by: Augustin Cavalier <waddlesplash@gmail.com>
Coding style looks OK to me and there are multiple comments that
it works, so just merging it.

* Applied patch from luroh as part of #7433 -- sorry for the long delay!


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42626 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Applied patch by idefix that improves the integration with Linux, and let
bfs_fuse act as a mount helper. This closes ticket #7433. Thanks a lot!


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@41258 a95241bf-73f2-0310-859d-f6bbb57e9c96

Build fix (on 64 bit hosts).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35819 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Jens Arm:
* You have to add "-d" to the bfs_fuse command line to get debug output now,
in non-debug mode this speeds up operations a lot.
* Errors during initialization and finalization are dumped to the syslog if
not in debug mode.

Thanks a lot!


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31813 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Jens Arm with cleanup by myself:
Implemented the statfs operation which helps to get
information like used and free blocks on the volume.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31716 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Jens Arm: Fixed swapped arguments in _kern_create_[sym]link()
invocations.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31689 a95241bf-73f2-0310-859d-f6bbb57e9c96

Small coding style fix.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31410 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Raghuram Nagireddy:
Re-use the kernel emulation of the FS shell to implement a FUSE module
for BFS. In theory, it could use any Haiku file system implementation
just like the FS shell itself, but currently only the BFS code supports
being compiled as an FS shell module. The build target is <build>bfs_fuse
On Ubuntu, you would do this:

sudo apt-get install libfuse-dev
jam \<build\>bfs_fuse
mkdir path/to/moundPoint
path/to/bfs_fuse /dev/sdaX path/to/mountPoint

And that will mount your BFS volume at /dev/sdaX
read/write. As this is new code, you should be careful with your
data and expect potential data loss. Not that I don't trust Raghu's
code, but a warning is always better with such things. So far, my
tests have been successful and it is great to finally have write
support for BFS in Linux! Thanks a lot, Raghu, for your great work!


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31409 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Applied patch from luroh as part of #7433 -- sorry for the long delay!


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42626 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Applied patch by idefix that improves the integration with Linux, and let
bfs_fuse act as a mount helper. This closes ticket #7433. Thanks a lot!


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@41258 a95241bf-73f2-0310-859d-f6bbb57e9c96

Build fix (on 64 bit hosts).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35819 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Jens Arm:
* You have to add "-d" to the bfs_fuse command line to get debug output now,
in non-debug mode this speeds up operations a lot.
* Errors during initialization and finalization are dumped to the syslog if
not in debug mode.

Thanks a lot!


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31813 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Jens Arm with cleanup by myself:
Implemented the statfs operation which helps to get
information like used and free blocks on the volume.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31716 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Jens Arm: Fixed swapped arguments in _kern_create_[sym]link()
invocations.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31689 a95241bf-73f2-0310-859d-f6bbb57e9c96

Small coding style fix.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31410 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Raghuram Nagireddy:
Re-use the kernel emulation of the FS shell to implement a FUSE module
for BFS. In theory, it could use any Haiku file system implementation
just like the FS shell itself, but currently only the BFS code supports
being compiled as an FS shell module. The build target is <build>bfs_fuse
On Ubuntu, you would do this:

sudo apt-get install libfuse-dev
jam \<build\>bfs_fuse
mkdir path/to/moundPoint
path/to/bfs_fuse /dev/sdaX path/to/mountPoint

And that will mount your BFS volume at /dev/sdaX
read/write. As this is new code, you should be careful with your
data and expect potential data loss. Not that I don't trust Raghu's
code, but a warning is always better with such things. So far, my
tests have been successful and it is great to finally have write
support for BFS in Linux! Thanks a lot, Raghu, for your great work!


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31409 a95241bf-73f2-0310-859d-f6bbb57e9c96