linux-toradex.git/include/uapi/linux/fuse.h, branch v5.10-rc3

fuse: add submount support to

2020-09-18T13:17:40+00:00

- Add fuse_attr.flags

- Add FUSE_ATTR_SUBMOUNT

  This is a flag for fuse_attr.flags that indicates that the given entry
  resides on a different filesystem than the parent, and as such should
  have a different st_dev.

- Add FUSE_SUBMOUNTS

  The client sets this flag if it supports automounting directories.

Signed-off-by: Max Reitz 
Signed-off-by: Miklos Szeredi

virtiofs: implement dax read/write operations

2020-09-10T09:39:23+00:00

This patch implements basic DAX support. mmap() is not implemented
yet and will come in later patches. This patch looks into implemeting
read/write.

We make use of interval tree to keep track of per inode dax mappings.

Do not use dax for file extending writes, instead just send WRITE message
to daemon (like we do for direct I/O path). This will keep write and
i_size change atomic w.r.t crash.

Signed-off-by: Stefan Hajnoczi 
Signed-off-by: Dr. David Alan Gilbert 
Signed-off-by: Vivek Goyal 
Signed-off-by: Liu Bo 
Signed-off-by: Peng Tao 
Cc: Dave Chinner 
Signed-off-by: Miklos Szeredi

virtiofs: introduce setupmapping/removemapping commands

2020-09-10T09:39:23+00:00

Introduce two new fuse commands to setup/remove memory mappings. This
will be used to setup/tear down file mapping in dax window.

Signed-off-by: Vivek Goyal 
Signed-off-by: Peng Tao 
Signed-off-by: Miklos Szeredi

virtiofs: implement FUSE_INIT map_alignment field

2020-09-10T09:39:22+00:00

The device communicates FUSE_SETUPMAPPING/FUSE_REMOVMAPPING alignment
constraints via the FUST_INIT map_alignment field.  Parse this field and
ensure our DAX mappings meet the alignment constraints.

We don't actually align anything differently since our mappings are
already 2MB aligned.  Just check the value when the connection is
established.  If it becomes necessary to honor arbitrary alignments in
the future we'll have to adjust how mappings are sized.

The upshot of this commit is that we can be confident that mappings will
work even when emulating x86 on Power and similar combinations where the
host page sizes are different.

Signed-off-by: Stefan Hajnoczi 
Signed-off-by: Vivek Goyal 
Signed-off-by: Miklos Szeredi

fuse: Add changelog entries for protocols 7.1 - 7.8

2019-10-23T12:26:37+00:00

Retroactively add changelog entry for FUSE protocols 7.1 through 7.8.

Signed-off-by: Alan Somers 
Signed-off-by: Miklos Szeredi

fuse: reserve values for mapping protocol

2019-09-12T12:59:41+00:00

SETUPMAPPING is a command for use with 'virtiofsd', a fuse-over-virtio
implementation; it may find use in other fuse impelementations as well in
which the kernel does not have access to the address space of the daemon
directly.

A SETUPMAPPING operation causes a section of a file to be mapped into a
memory window visible to the kernel.  The offsets in the file and the
window are defined by the kernel performing the operation.

The daemon may reject the request, for reasons including permissions and
limited resources.

When a request perfectly overlaps a previous mapping, the previous mapping
is replaced.  When a mapping partially overlaps a previous mapping, the
previous mapping is split into one or two smaller mappings.

REMOVEMAPPING is the complement to SETUPMAPPING; it unmaps a range of
mapped files from the window visible to the kernel.

The map_alignment field communicates the alignment constraint for
FUSE_SETUPMAPPING/FUSE_REMOVEMAPPING and allows the daemon to constrain the
addresses and file offsets chosen by the kernel.

Signed-off-by: Dr. David Alan Gilbert 
Signed-off-by: Vivek Goyal 
Signed-off-by: Stefan Hajnoczi 
Signed-off-by: Miklos Szeredi

fuse: reserve byteswapped init opcodes

2019-09-12T12:59:41+00:00

virtio fs tunnels fuse over a virtio channel.  One issue is two sides might
be speaking different endian-ness. To detects this, host side looks at the
opcode value in the FUSE_INIT command.  Works fine at the moment but might
fail if a future version of fuse will use such an opcode for
initialization.  Let's reserve this opcode so we remember and don't do
this.

Same for CUSE_INIT.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Miklos Szeredi

fuse: add FUSE_WRITE_KILL_PRIV

2019-05-27T09:42:36+00:00

In the FOPEN_DIRECT_IO case the write path doesn't call file_remove_privs()
and that means setuid bit is not cleared if unpriviliged user writes to a
file with setuid bit set.

pjdfstest chmod test 12.t tests this and fails.

Fix this by adding a flag to the FUSE_WRITE message that requests clearing
privileges on the given file.  This needs 

This better than just calling fuse_remove_privs(), because the attributes
may not be up to date, so in that case a write may miss clearing the
privileges.

Test case:

  $ passthrough_ll /mnt/pasthrough-mnt -o default_permissions,allow_other,cache=never
  $ mkdir /mnt/pasthrough-mnt/testdir
  $ cd /mnt/pasthrough-mnt/testdir
  $ prove -rv pjdfstests/tests/chmod/12.t

Reported-by: Vivek Goyal 
Signed-off-by: Miklos Szeredi 
Tested-by: Vivek Goyal

fuse: Add ioctl flag for x32 compat ioctl

2019-04-24T15:05:07+00:00

Currently, a CUSE server running on a 64-bit kernel can tell when an ioctl
request comes from a process running a 32-bit ABI, but cannot tell whether
the requesting process is using legacy IA32 emulation or x32 ABI.  In
particular, the server does not know the size of the client process's
`time_t` type.

For 64-bit kernels, the `FUSE_IOCTL_COMPAT` and `FUSE_IOCTL_32BIT` flags
are currently set in the ioctl input request (`struct fuse_ioctl_in` member
`flags`) for a 32-bit requesting process.  This patch defines a new flag
`FUSE_IOCTL_COMPAT_X32` and sets it if the 32-bit requesting process is
using the x32 ABI.  This allows the server process to distinguish between
requests coming from client processes using IA32 emulation or the x32 ABI
and so infer the size of the client process's `time_t` type and any other
IA32/x32 differences.

Signed-off-by: Ian Abbott 
Signed-off-by: Miklos Szeredi

fuse: fix changelog entry for protocol 7.9

2019-04-24T15:05:07+00:00

Retroactively add changelog entry for the atime and mtime "now" flags.
This was an oversight in commit 17637cbaba59 ("fuse: improve utimes
support").

Signed-off-by: Alan Somers 
Signed-off-by: Miklos Szeredi