On 7/18/25 01:38, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> Add the library methods so that fuse servers can manage an in-kernel
> iomap cache. This enables better performance on small IOs and is
> required if the filesystem needs synchronization between pagecache
> writes and writeback.
Sorry, if this ready to be merged? I don't see in linux master? Or part
of your other patches (will take some to go through these).
>
> Signed-off-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
> ---
> include/fuse_common.h | 9 +++++
> include/fuse_kernel.h | 34 +++++++++++++++++++
> include/fuse_lowlevel.h | 39 ++++++++++++++++++++++
> lib/fuse_lowlevel.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++
> lib/fuse_versionscript | 2 +
> 5 files changed, 166 insertions(+)
>
>
> diff --git a/include/fuse_common.h b/include/fuse_common.h
> index 98cb8f656efd13..1237cc2656b9c4 100644
> --- a/include/fuse_common.h
> +++ b/include/fuse_common.h
> @@ -1164,6 +1164,7 @@ int fuse_convert_to_conn_want_ext(struct fuse_conn_info *conn);
> */
> #if FUSE_USE_VERSION >= FUSE_MAKE_VERSION(3, 18)
> #define FUSE_IOMAP_TYPE_PURE_OVERWRITE (0xFFFF) /* use read mapping data */
> +#define FUSE_IOMAP_TYPE_NULL (0xFFFE) /* no mapping here */
> #define FUSE_IOMAP_TYPE_HOLE 0 /* no blocks allocated, need allocation */
> #define FUSE_IOMAP_TYPE_DELALLOC 1 /* delayed allocation blocks */
> #define FUSE_IOMAP_TYPE_MAPPED 2 /* blocks allocated at @addr */
> @@ -1208,6 +1209,11 @@ struct fuse_iomap {
> uint32_t dev; /* device cookie */
> };
>
> +struct fuse_iomap_inval {
> + uint64_t offset; /* file offset to invalidate, bytes */
> + uint64_t length; /* length to invalidate, bytes */
> +};
> +
> /* out of place write extent */
> #define FUSE_IOMAP_IOEND_SHARED (1U << 0)
> /* unwritten extent */
> @@ -1258,6 +1264,9 @@ struct fuse_iomap_config{
> int64_t s_maxbytes; /* max file size */
> };
>
> +/* invalidate to end of file */
> +#define FUSE_IOMAP_INVAL_TO_EOF (~0ULL)
> +
> #endif /* FUSE_USE_VERSION >= 318 */
>
> /* ----------------------------------------------------------- *
> diff --git a/include/fuse_kernel.h b/include/fuse_kernel.h
> index 3c704f03434693..f1a93dbd1ff443 100644
> --- a/include/fuse_kernel.h
> +++ b/include/fuse_kernel.h
> @@ -243,6 +243,8 @@
> * - add FUSE_IOMAP_DIRECTIO/FUSE_ATTR_IOMAP_DIRECTIO for direct I/O support
> * - add FUSE_IOMAP_FILEIO/FUSE_ATTR_IOMAP_FILEIO for buffered I/O support
> * - add FUSE_IOMAP_CONFIG so the fuse server can configure more fs geometry
> + * - add FUSE_NOTIFY_IOMAP_UPSERT and FUSE_NOTIFY_IOMAP_INVAL so fuse servers
> + * can cache iomappings in the kernel
Personally I prefer a preparation patch, that just syncs the entire
fuse_kernel.h from linux-<version>. Also this file might get renamed to
fuse_kernel_linux.h, there seems to be interest from BSD and OSX to have
their own headers.
> */
>
> #ifndef _LINUX_FUSE_H
> @@ -699,6 +701,8 @@ enum fuse_notify_code {
> FUSE_NOTIFY_DELETE = 6,
> FUSE_NOTIFY_RESEND = 7,
> FUSE_NOTIFY_INC_EPOCH = 8,
> + FUSE_NOTIFY_IOMAP_UPSERT = 9,
> + FUSE_NOTIFY_IOMAP_INVAL = 10,
> FUSE_NOTIFY_CODE_MAX,
> };
>
> @@ -1406,4 +1410,34 @@ struct fuse_iomap_config_out {
> int64_t s_maxbytes; /* max file size */
> };
>
> +struct fuse_iomap_upsert_out {
> + uint64_t nodeid; /* Inode ID */
> + uint64_t attr_ino; /* matches fuse_attr:ino */
> +
> + uint64_t read_offset; /* file offset of mapping, bytes */
> + uint64_t read_length; /* length of mapping, bytes */
> + uint64_t read_addr; /* disk offset of mapping, bytes */
> + uint16_t read_type; /* FUSE_IOMAP_TYPE_* */
> + uint16_t read_flags; /* FUSE_IOMAP_F_* */
> + uint32_t read_dev; /* device cookie */
> +
> + uint64_t write_offset; /* file offset of mapping, bytes */
> + uint64_t write_length; /* length of mapping, bytes */
> + uint64_t write_addr; /* disk offset of mapping, bytes */
> + uint16_t write_type; /* FUSE_IOMAP_TYPE_* */
> + uint16_t write_flags; /* FUSE_IOMAP_F_* */
> + uint32_t write_dev; /* device cookie * */
> +};
> +
> +struct fuse_iomap_inval_out {
> + uint64_t nodeid; /* Inode ID */
> + uint64_t attr_ino; /* matches fuse_attr:ino */
> +
> + uint64_t read_offset; /* range to invalidate read iomaps, bytes */
> + uint64_t read_length; /* can be FUSE_IOMAP_INVAL_TO_EOF */
> +
> + uint64_t write_offset; /* range to invalidate write iomaps, bytes */
> + uint64_t write_length; /* can be FUSE_IOMAP_INVAL_TO_EOF */
> +};
> +
> #endif /* _LINUX_FUSE_H */
> diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
> index fd7df5c2c11e16..f690c62fcdd61c 100644
> --- a/include/fuse_lowlevel.h
> +++ b/include/fuse_lowlevel.h
> @@ -2101,6 +2101,45 @@ int fuse_lowlevel_notify_retrieve(struct fuse_session *se, fuse_ino_t ino,
> * @return positive device id for success, zero for failure
> */
> int fuse_iomap_add_device(struct fuse_session *se, int fd, unsigned int flags);
> +
> +/**
> + * Upsert some file mapping information into the kernel. This is necessary
> + * for filesystems that require coordination of mapping state changes between
> + * buffered writes and writeback, and desirable for better performance
> + * elsewhere.
> + *
> + * Added in FUSE protocol version 7.99. If the kernel does not support
7.99?
Thanks,
Bernd
