kernel/linux.git/include/net/9p/client.h, branch v7.2-rc2

9p: Cache negative dentries for lookup performance

2026-06-21T05:22:56+00:00

Not caching negative dentries can result in poor performance for workloads that repeatedly look up non-existent paths. Each such lookup triggers a full 9P transaction with the server, adding unnecessary overhead. A typical example is source compilation, where multiple cc1 processes are spawned and repeatedly search for the same missing header files over and over again. This change enables caching of negative dentries, so that lookups for known non-existent paths do not require a full 9P transaction. The cached negative dentries are retained for a configurable duration (expressed in milliseconds), as specified by the ndentry_timeout field in struct v9fs_session_info. If set to -1, negative dentries are cached indefinitely. This optimization reduces lookup overhead and improves performance for workloads involving frequent access to non-existent paths. Signed-off-by: Remi Pommarel Message-ID: Signed-off-by: Dominique Martinet

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

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 client parameter to p9_req_put()

2022-07-09T05:38:35+00:00

This is to aid in adding mempools, in the next patch. Link: https://lkml.kernel.org/r/20220704014243.153050-2-kent.overstreet@gmail.com Signed-off-by: Kent Overstreet Cc: Eric Van Hensbergen Cc: Latchesar Ionkov Signed-off-by: Dominique Martinet

9p: Drop kref usage

2022-07-09T05:38:12+00:00

An upcoming patch is going to require passing the client through p9_req_put() -> p9_req_free(), but that's awkward with the kref indirection - so this patch switches to using refcount_t directly. Link: https://lkml.kernel.org/r/20220704014243.153050-1-kent.overstreet@gmail.com Signed-off-by: Kent Overstreet Cc: Eric Van Hensbergen Cc: Latchesar Ionkov Signed-off-by: Dominique Martinet

9p fid refcount: add a 9p_fid_ref tracepoint

2022-07-02T09:52:21+00:00

This adds a tracepoint event for 9p fid lifecycle tracing: when a fid is created, its reference count increased/decreased, and freed. The new 9p_fid_ref tracepoint should help anyone wishing to debug any fid problem such as missing clunk (destroy) or use-after-free. Link: https://lkml.kernel.org/r/20220612085330.1451496-6-asmadeus@codewreck.org Signed-off-by: Dominique Martinet

9p fid refcount: add p9_fid_get/put wrappers

2022-07-02T09:52:21+00:00

I was recently reminded that it is not clear that p9_client_clunk() was actually just decrementing refcount and clunking only when that reaches zero: make it clear through a set of helpers. This will also allow instrumenting refcounting better for debugging next patch Link: https://lkml.kernel.org/r/20220612085330.1451496-5-asmadeus@codewreck.org Reviewed-by: Tyler Hicks Reviewed-by: Christian Schoenebeck Signed-off-by: Dominique Martinet

9p: fix a bunch of checkpatch warnings

2021-11-04T12:04:25+00:00

Sohaib Mohamed started a serie of tiny and incomplete checkpatch fixes but seemingly stopped halfway -- take over and do most of it. This is still missing net/9p/trans* and net/9p/protocol.c for a later time... Link: http://lkml.kernel.org/r/20211102134608.1588018-3-dominique.martinet@atmark-techno.com Signed-off-by: Dominique Martinet