Implement the VFS interface for the 9P filesystem. Map the U-Boot filesystem operations to the underlying 9P protocol client. It also registers the 9P filesystem type within the U-Boot generic fs framework, allowing it to bypass standard block device partition checks since 9P is a network/host-backed filesystem.
Signed-off-by: Kuan-Wei Chiu <[email protected]> --- fs/9p/9p.c | 137 +++++++++++++++++++++++++++++++++++++++++++++++++ fs/9p/Kconfig | 8 +++ fs/9p/Makefile | 5 ++ fs/Kconfig | 2 + fs/Makefile | 1 + fs/fs.c | 35 +++++++++++++ include/fs.h | 1 + 7 files changed, 189 insertions(+) create mode 100644 fs/9p/9p.c create mode 100644 fs/9p/Kconfig create mode 100644 fs/9p/Makefile diff --git a/fs/9p/9p.c b/fs/9p/9p.c new file mode 100644 index 00000000000..37d60c03891 --- /dev/null +++ b/fs/9p/9p.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2026, Kuan-Wei Chiu <[email protected]> + */ + +#include <9p.h> +#include <config.h> +#include <log.h> +#include <asm/unaligned.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> + +static u32 p9_root_fid = 1; + +int p9_fs_probe(struct blk_desc *fs_dev_desc, struct disk_partition *fs_partition) +{ + struct p9_client *c = p9_get_client(); + + if (!c) { + log_err("9P Error: No transport client registered\n"); + return -ENODEV; + } + + if (p9_client_version(c)) + return -EIO; + if (p9_client_attach(c, p9_root_fid, "root", "")) + return -EIO; + + return 0; +} + +int p9_fs_ls(const char *dirname) +{ + struct p9_client *c = p9_get_client(); + u32 fid = p9_client_alloc_fid(c); + u8 buf[4096]; + u32 actread; + u8 *ptr, *end; + u16 name_len; + u8 d_type; + + if (p9_client_walk(c, p9_root_fid, fid, dirname)) + return -ENOENT; + if (p9_client_lopen(c, fid, P9_O_RDONLY)) + return -EIO; + + if (p9_client_readdir(c, fid, 0, sizeof(buf), buf, &actread)) { + p9_client_clunk(c, fid); + return -EIO; + } + + if (actread == 0) { + printf(" (empty directory)\n"); + } else { + ptr = buf; + end = buf + actread; + while (ptr < end) { + ptr += P9_DIRENT_OFFSET; + d_type = *ptr++; + name_len = get_unaligned_le16(ptr); + ptr += 2; + printf(" %s %.*s\n", (d_type == P9_DT_DIR) ? "<DIR> " : " ", + name_len, ptr); + ptr += name_len; + } + } + + p9_client_clunk(c, fid); + return 0; +} + +int p9_fs_size(const char *filename, loff_t *size) +{ + struct p9_client *c = p9_get_client(); + u32 fid = p9_client_alloc_fid(c); + int ret; + + if (p9_client_walk(c, p9_root_fid, fid, filename)) + return -ENOENT; + ret = p9_client_stat(c, fid, size); + p9_client_clunk(c, fid); + + return ret; +} + +int p9_fs_exists(const char *filename) +{ + loff_t size; + + return (p9_fs_size(filename, &size) == 0) ? 1 : 0; +} + +int p9_fs_read(const char *filename, void *buf, loff_t offset, loff_t len, loff_t *actread) +{ + struct p9_client *c = p9_get_client(); + u32 fid = p9_client_alloc_fid(c); + u32 read_bytes = 0; + loff_t total_read = 0; + loff_t remaining; + u32 req_len; + u8 *dst = (u8 *)buf; + int ret = 0; + + if (p9_client_walk(c, p9_root_fid, fid, filename)) + return -ENOENT; + if (p9_client_lopen(c, fid, P9_O_RDONLY)) { + p9_client_clunk(c, fid); + return -EIO; + } + + while (1) { + if (len == 0) { + req_len = 0; + } else { + remaining = len - total_read; + if (remaining == 0) + break; + + req_len = (remaining > 0xFFFFFFFF) ? 0xFFFFFFFF : (u32)remaining; + } + + ret = p9_client_read(c, fid, offset, req_len, dst, &read_bytes); + + if (ret != 0 || read_bytes == 0) + break; + + total_read += read_bytes; + offset += read_bytes; + dst += read_bytes; + } + + *actread = total_read; + p9_client_clunk(c, fid); + + return (total_read > 0 || ret == 0) ? 0 : ret; +} diff --git a/fs/9p/Kconfig b/fs/9p/Kconfig new file mode 100644 index 00000000000..bc6d4962288 --- /dev/null +++ b/fs/9p/Kconfig @@ -0,0 +1,8 @@ +config FS_9P + bool "9P filesystem support" + depends on NET_9P + help + This provides support for the 9P2000.L filesystem. + + To use this filesystem, you also need to enable a 9P + transport driver. diff --git a/fs/9p/Makefile b/fs/9p/Makefile new file mode 100644 index 00000000000..c7f7553e8f4 --- /dev/null +++ b/fs/9p/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0-or-later +# +# Copyright (C) 2026, Kuan-Wei Chiu <[email protected]> + +obj-y += 9p.o diff --git a/fs/Kconfig b/fs/Kconfig index e0b0b901e1d..e4aa726ea35 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -26,4 +26,6 @@ source "fs/squashfs/Kconfig" source "fs/erofs/Kconfig" +source "fs/9p/Kconfig" + endmenu diff --git a/fs/Makefile b/fs/Makefile index ce5e74257a0..5aa34b39172 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -26,5 +26,6 @@ obj-$(CONFIG_CMD_UBIFS) += ubifs/ obj-$(CONFIG_CMD_ZFS) += zfs/ obj-$(CONFIG_FS_SQUASHFS) += squashfs/ obj-$(CONFIG_FS_EROFS) += erofs/ +obj-$(CONFIG_FS_9P) += 9p/ endif obj-y += fs_internal.o diff --git a/fs/fs.c b/fs/fs.c index 8ea50a6c13c..0bb996dede5 100644 --- a/fs/fs.c +++ b/fs/fs.c @@ -32,6 +32,7 @@ #include <squashfs.h> #include <erofs.h> #include <exfat.h> +#include <9p.h> static struct blk_desc *fs_dev_desc; static int fs_dev_part; @@ -398,6 +399,26 @@ static struct fstype_info fstypes[] = { .mkdir = exfat_fs_mkdir, .rename = exfat_fs_rename, }, +#endif +#if CONFIG_IS_ENABLED(FS_9P) + { + .fstype = FS_TYPE_9P, + .name = "9p", + .null_dev_desc_ok = true, + .probe = p9_fs_probe, + .close = fs_close_unsupported, + .ls = p9_fs_ls, + .exists = p9_fs_exists, + .size = p9_fs_size, + .read = p9_fs_read, + .write = fs_write_unsupported, + .uuid = fs_uuid_unsupported, + .opendir = fs_opendir_unsupported, + .unlink = fs_unlink_unsupported, + .mkdir = fs_mkdir_unsupported, + .ln = fs_ln_unsupported, + .rename = fs_rename_unsupported, + }, #endif { .fstype = FS_TYPE_ANY, @@ -464,6 +485,20 @@ int fs_set_blk_dev(const char *ifname, const char *dev_part_str, int fstype) struct fstype_info *info; int part, i; + /* Intercept 9p to bypass block device partition checks */ + if (CONFIG_IS_ENABLED(FS_9P) && !strncmp(ifname, "9p", 2)) { + for (i = 0, info = fstypes; i < ARRAY_SIZE(fstypes); i++, info++) { + if (info->fstype == FS_TYPE_9P) { + fs_dev_desc = NULL; + fs_type = FS_TYPE_9P; + if (info->probe(fs_dev_desc, NULL)) + return -1; + return 0; + } + } + return -1; + } + part = part_get_info_by_dev_and_name_or_num(ifname, dev_part_str, &fs_dev_desc, &fs_partition, 1); if (part < 0) diff --git a/include/fs.h b/include/fs.h index bec02117737..8afc81c0017 100644 --- a/include/fs.h +++ b/include/fs.h @@ -19,6 +19,7 @@ struct cmd_tbl; #define FS_TYPE_EROFS 7 #define FS_TYPE_SEMIHOSTING 8 #define FS_TYPE_EXFAT 9 +#define FS_TYPE_9P 10 struct blk_desc; -- 2.55.0.rc2.803.g1fd1e6609c-goog
