linux-toradex.git/include/net/9p, branch master

9p: convert to the new mount API

2025-11-03T07:49:53+00:00

Convert 9p to the new mount API. This patch consolidates all parsing
into fs/9p/v9fs.c, which stores all results into a filesystem context
which can be passed to the various transports as needed.

Some of the parsing helper functions such as get_cache_mode() have been
eliminated in favor of using the new mount API's enum param type,
for simplicity.

Signed-off-by: Eric Sandeen 
Message-ID: <20251010214222.1347785-5-sandeen@redhat.com>
[ Dominique: handled source explicitly as per follow-up discussion ]
Signed-off-by: Dominique Martinet

9p: create a v9fs_context structure to hold parsed options

2025-11-03T07:49:53+00:00

This patch creates a new v9fs_context structure which includes
new p9_session_opts and p9_client_opts structures, as well as
re-using the existing p9_fd_opts and p9_rdma_opts to store options
during parsing. The new structure will be used in the next
commit to pass all parsed options to the appropriate transports.

Signed-off-by: Eric Sandeen 
Message-ID: <20251010214222.1347785-4-sandeen@redhat.com>
Signed-off-by: Dominique Martinet

net/9p: move structures and macros to header files

2025-11-03T07:49:53+00:00

With the new mount API all option parsing will need to happen
in fs/v9fs.c, so move some existing data structures and macros
to header files to facilitate this. Rename some to reflect
the transport they are used for (rdma, fd, etc), for clarity.

Signed-off-by: Eric Sandeen 
Message-ID: <20251010214222.1347785-3-sandeen@redhat.com>
Signed-off-by: Dominique Martinet

net/9p: cleanup: change p9_trans_module->def to bool

2025-11-03T07:49:29+00:00

'->def' is only ever used as a true/false flag

Reported-by: Christophe JAILLET 
Message-ID: <20251103-v9fs_trans_def_bool-v1-1-f33dc7ed9e81@codewreck.org>
Signed-off-by: Dominique Martinet

9p: Use kvmalloc for message buffers on supported transports

2025-11-03T07:41:24+00:00

While developing a 9P server (https://github.com/Barre/ZeroFS) and
testing it under high-load, I was running into allocation failures.
The failures occur even with plenty of free memory available because
kmalloc requires contiguous physical memory.

This results in errors like:
ls: page allocation failure: order:7, mode:0x40c40(GFP_NOFS|__GFP_COMP)

This patch introduces a transport capability flag (supports_vmalloc)
that indicates whether a transport can work with vmalloc'd buffers
(non-physically contiguous memory). Transports requiring DMA should
leave this flag as false.

The fd-based transports (tcp, unix, fd) set this flag to true, and
p9_fcall_init will use kvmalloc instead of kmalloc for these
transports. This allows the allocator to fall back to vmalloc when
contiguous physical memory is not available.

Additionally, if kmem_cache_alloc fails, the code falls back to
kvmalloc for transports that support it.

Signed-off-by: Pierre Barre 
Reviewed-by: Christian Schoenebeck 
Message-ID: 
Signed-off-by: Dominique Martinet

netfs, 9p: Implement helpers for new write code

2024-05-01T17:07:37+00:00

Implement the helpers for the new write code in 9p.  There's now an
optional ->prepare_write() that allows the filesystem to set the parameters
for the next write, such as maximum size and maximum segment count, and an
->issue_write() that is called to initiate an (asynchronous) write
operation.

Signed-off-by: David Howells 
Reviewed-by: Jeff Layton 
cc: Eric Van Hensbergen 
cc: Latchesar Ionkov 
cc: Dominique Martinet 
cc: Christian Schoenebeck 
cc: v9fs@lists.linux.dev
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org

9p: Add additional debug flags and open modes

2023-03-27T02:33:48+00:00

Add some additional debug flags to assist with debugging
cache changes.  Also add some additional open modes so we
can track cache state in fids more directly.

Signed-off-by: Eric Van Hensbergen

net/9p: distinguish zero-copy requests

2022-12-05T22:30:55+00:00

Add boolean `zc` member to struct p9_fcall to distinguish zero-copy
messages (not using the linear `sdata` buffer for message payload) from
regular messages (which do copy message payload to `sdata` before being
further processed).

This new member is appended to end of structure to avoid inserting huge
padding in generated layout.

Link: https://lkml.kernel.org/r/8f2a5c12a446c3b544da64e0b1550e1fb2d6f972.1669144861.git.linux_oss@crudebyte.com
Signed-off-by: Christian Schoenebeck 
Tested-by: Stefano Stabellini 
Signed-off-by: Dominique Martinet

net/9p: add 'pooled_rbuffers' flag to struct p9_trans_module

2022-10-04T22:05:41+00:00

This is a preparatory change for the subsequent patch: the RDMA
transport pulls the buffers for its 9p response messages from a
shared pool. [1] So this case has to be considered when choosing
an appropriate response message size in the subsequent patch.

Link: https://lore.kernel.org/all/Ys3jjg52EIyITPua@codewreck.org/ [1]
Link: https://lkml.kernel.org/r/79d24310226bc4eb037892b5c097ec4ad4819a03.1657920926.git.linux_oss@crudebyte.com
Signed-off-by: Christian Schoenebeck 
Signed-off-by: Dominique Martinet

9p: add P9_ERRMAX for 9p2000 and 9p2000.u

2022-10-04T22:05:41+00:00

Add P9_ERRMAX macro to 9P protocol header which reflects the maximum
error string length of Rerror replies for 9p2000 and 9p2000.u protocol
versions. Unfortunately a maximum error string length is not defined by
the 9p2000 spec, picking 128 as value for now, as this seems to be a
common max. size for POSIX error strings in practice.

9p2000.L protocol version uses Rlerror replies instead which does not
contain an error string.

Link: https://lkml.kernel.org/r/3f23191d21032e7c14852b1e1a4ae26417a36739.1657920926.git.linux_oss@crudebyte.com
Signed-off-by: Christian Schoenebeck 
Signed-off-by: Dominique Martinet