From: John Groves <[email protected]> Add the minimal fuse plumbing that later famfs commits build on:
- Kconfig: add FUSE_FAMFS_DAX to control compilation of famfs support within fuse. - uapi: add the FUSE_DAX_FMAP flag for the INIT request/reply, by which the server and kernel negotiate famfs (in-kernel fs-dax map) support. - fuse_conn->famfs_iomap to mark a famfs-enabled connection. Reviewed-by: Joanne Koong <[email protected]> Reviewed-by: Dave Jiang <[email protected]> Signed-off-by: John Groves <[email protected]> --- fs/fuse/Kconfig | 13 +++++++++++++ fs/fuse/fuse_i.h | 3 +++ fs/fuse/inode.c | 6 ++++++ include/uapi/linux/fuse.h | 5 +++++ 4 files changed, 27 insertions(+) diff --git a/fs/fuse/Kconfig b/fs/fuse/Kconfig index 3a4ae632c94a..17fe1f490cbd 100644 --- a/fs/fuse/Kconfig +++ b/fs/fuse/Kconfig @@ -76,3 +76,16 @@ config FUSE_IO_URING If you want to allow fuse server/client communication through io-uring, answer Y + +config FUSE_FAMFS_DAX + bool "FUSE support for fs-dax filesystems backed by devdax" + depends on FUSE_FS + depends on DEV_DAX_FSDEV + default FUSE_FS + help + This enables the fabric-attached memory file system (famfs), + which enables formatting devdax memory as a file system. Famfs + is primarily intended for scale-out shared access to + disaggregated memory. + + To enable famfs or other fuse/fs-dax file systems, answer Y diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index f450194e877f..9c354118c931 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -711,6 +711,9 @@ struct fuse_conn { /** @sync_init: Is synchronous FUSE_INIT allowed? */ unsigned int sync_init:1; + /** @famfs_iomap: dev_dax_iomap support for famfs */ + unsigned int famfs_iomap:1; + /** @max_stack_depth: Maximum stack depth for passthrough backing files */ int max_stack_depth; diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 77c21b28b6fa..c347471d04b6 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1406,6 +1406,10 @@ static void process_init_reply(struct fuse_args *args, int error) if (flags & FUSE_REQUEST_TIMEOUT) timeout = arg->request_timeout; + + if (IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) && + flags & FUSE_DAX_FMAP) + fc->famfs_iomap = 1; } else { ra_pages = fc->max_read / PAGE_SIZE; fc->no_lock = 1; @@ -1473,6 +1477,8 @@ static struct fuse_init_args *fuse_new_init(struct fuse_mount *fm) flags |= FUSE_SUBMOUNTS; if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) flags |= FUSE_PASSTHROUGH; + if (IS_ENABLED(CONFIG_FUSE_FAMFS_DAX)) + flags |= FUSE_DAX_FMAP; /* * This is just an information flag for fuse server. No need to check diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index c13e1f9a2f12..25686f088e6a 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -240,6 +240,9 @@ * - add FUSE_COPY_FILE_RANGE_64 * - add struct fuse_copy_file_range_out * - add FUSE_NOTIFY_PRUNE + * + * 7.46 + * - Add FUSE_DAX_FMAP capability - ability to handle in-kernel fsdax maps */ #ifndef _LINUX_FUSE_H @@ -448,6 +451,7 @@ struct fuse_file_lock { * FUSE_OVER_IO_URING: Indicate that client supports io-uring * FUSE_REQUEST_TIMEOUT: kernel supports timing out requests. * init_out.request_timeout contains the timeout (in secs) + * FUSE_DAX_FMAP: kernel supports dev_dax_iomap (aka famfs) fmaps */ #define FUSE_ASYNC_READ (1 << 0) #define FUSE_POSIX_LOCKS (1 << 1) @@ -495,6 +499,7 @@ struct fuse_file_lock { #define FUSE_ALLOW_IDMAP (1ULL << 40) #define FUSE_OVER_IO_URING (1ULL << 41) #define FUSE_REQUEST_TIMEOUT (1ULL << 42) +#define FUSE_DAX_FMAP (1ULL << 43) /** * CUSE INIT request/reply flags -- 2.53.0
