From 39a923f6c3c471f169552cf4e98b02c5173c2283 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Wed, 28 Feb 2024 21:14:30 -0500 Subject: kernel: Add initial VFS implementation Signed-off-by: Ian Moffett --- sys/kern/init_main.c | 3 + sys/kern/vfs_cache.c | 96 +++++++++++++++++++++++++ sys/kern/vfs_init.c | 78 ++++++++++++++++++++ sys/kern/vfs_lookup.c | 123 ++++++++++++++++++++++++++++++++ sys/kern/vfs_subr.c | 193 ++++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 493 insertions(+) create mode 100644 sys/kern/vfs_cache.c create mode 100644 sys/kern/vfs_init.c create mode 100644 sys/kern/vfs_lookup.c create mode 100644 sys/kern/vfs_subr.c (limited to 'sys/kern') diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c index 5f7cafa..c55ece2 100644 --- a/sys/kern/init_main.c +++ b/sys/kern/init_main.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -89,6 +90,8 @@ main(void) processor_init(); list_timers(); + vfs_init(); + sched_init(); ci = this_cpu(); diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c new file mode 100644 index 0000000..44a8e27 --- /dev/null +++ b/sys/kern/vfs_cache.c @@ -0,0 +1,96 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include +#include +#include +#include + +static struct mountlist_entry *mountlist = NULL; + +int +vfs_cache_mp(struct mount *mp, const char *path) +{ + size_t hash = vfs_hash_path(path); + struct mountlist_entry *entry; + + if (hash == 0) { + /* Something is wrong with the path */ + return -EINVAL; + } + + if (vfs_cache_fetch_mp(path, NULL) == 0) { + /* Cache hit, do not duplicate this entry */ + return -EEXIST; + } + + mp->phash = hash; + entry = &mountlist[hash % MOUNTLIST_SIZE]; + TAILQ_INSERT_TAIL(&entry->buckets, mp, link); + return 0; +} + +int +vfs_cache_fetch_mp(const char *path, struct mount **mp) +{ + size_t hash = vfs_hash_path(path); + struct mountlist_entry *entry; + struct mount *mount_iter; + + if (hash == 0) { + /* Something is wrong with the path */ + return -EINVAL; + } + + entry = &mountlist[hash % MOUNTLIST_SIZE]; + TAILQ_FOREACH(mount_iter, &entry->buckets, link) { + if (mount_iter->phash == hash) { + /* Cache hit */ + if (mp != NULL) *mp = mount_iter; + return 0; + } + } + + /* Cache miss */ + return -ENOENT; +} + +void +vfs_init_cache(void) +{ + mountlist = dynalloc(sizeof(struct mount) * MOUNTLIST_SIZE); + __assert(mountlist != NULL); + + for (size_t i = 0; i < MOUNTLIST_SIZE; ++i) { + TAILQ_INIT(&mountlist[i].buckets); + } +} diff --git a/sys/kern/vfs_init.c b/sys/kern/vfs_init.c new file mode 100644 index 0000000..bcda0dd --- /dev/null +++ b/sys/kern/vfs_init.c @@ -0,0 +1,78 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include +#include +#include +#include + +__MODULE_NAME("vfs"); +__KERNEL_META("$Hyra$: vfs.c, Ian Marco Moffett, " + "Hyra Virtual File System"); + +struct fs_info filesystems[] = { + { "initramfs", &g_initramfs_ops } +}; + +struct fs_info * +vfs_byname(const char *name) +{ + for (int i = 0; i < __ARRAY_COUNT(filesystems); ++i) { + if (strcmp(filesystems[i].name, name) == 0) { + return &filesystems[i]; + } + } + + return NULL; +} + +void +vfs_init(void) +{ + struct fs_info *info; + struct vfsops *vfsops; + + vfs_init_cache(); + + for (int i = 0; i < __ARRAY_COUNT(filesystems); ++i) { + info = &filesystems[i]; + vfsops = info->vfsops; + + __assert(vfsops->init != NULL); + vfsops->init(info); + + if (strcmp(info->name, "initramfs") == 0) { + /* Initramfs must be mounted */ + vfs_mount(&info->mp_root, "/ramdisk", MNT_RDONLY); + } + } +} diff --git a/sys/kern/vfs_lookup.c b/sys/kern/vfs_lookup.c new file mode 100644 index 0000000..748d5e2 --- /dev/null +++ b/sys/kern/vfs_lookup.c @@ -0,0 +1,123 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include + +/* + * Fetches the filename within a past at + * the nth index denoted by `idx' + * + * Returns memory allocated by dynalloc() + * containing the filename. + * + * XXX: MUST FREE RETURN VALUE WITH dynfree() WHEN + * DONE! + */ +char * +vfs_get_fname_at(const char *path, size_t idx) +{ + size_t pathlen = strlen(path); + size_t fname_len; + + char *path_tmp = dynalloc(pathlen + 2); + char *ret = NULL; + char *start_ptr, *ptr; + + /* Make one-based */ + ++idx; + + if (path_tmp == NULL) { + return NULL; + } + + ptr = path_tmp; + memcpy(path_tmp, path, pathlen + 1); + + /* + * We want to by default have a '/' at the end + * to keep the parsing logic from getting more + * complicated than it needs to be. + */ + path_tmp[pathlen] = '/'; + path_tmp[pathlen + 1] = '\0'; + + /* Skip any leading slashes */ + while (*ptr == '/') + ++ptr; + + start_ptr = ptr; + + /* Get each filename */ + while (*ptr != '\0') { + /* Handle duplicate delimiter */ + if (*ptr == '/' && *(ptr + 1) == '/') { + /* + * Snip this delimiter and skip, the next + * will be read and filename returned (if of course + * the index is reached). + */ + *(ptr++) = '\0'; + continue; + } + + if (*ptr == '/') { + *(ptr++) = '\0'; + + /* Continue if index not reached */ + if ((--idx) != 0) { + start_ptr = ptr; + continue; + } + + /* Index has been reached, start_ptr contains name */ + fname_len = strlen(start_ptr); + ret = dynalloc(fname_len + 1); + + if (ret != NULL) { + memcpy(ret, start_ptr, fname_len + 1); + } + break; + } + + ++ptr; + } + + dynfree(path_tmp); + return ret; +} + +struct vnode * +vfs_path_to_node(const char *path) +{ + /* TODO */ + return NULL; +} diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c new file mode 100644 index 0000000..04b644e --- /dev/null +++ b/sys/kern/vfs_subr.c @@ -0,0 +1,193 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include +#include +#include + +/* FNV-1a defines */ +#define FNV_OFFSET 14695981039346656037ULL +#define FNV_PRIME 1099511628211ULL + +/* + * 32-bit FNV-1a hash function + * https://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function + */ +static size_t +vfs_hash(const char *data) +{ + size_t hash = FNV_OFFSET; + const char *p = data; + + while (*p) { + hash ^= (size_t)(uint8_t)(*p); + hash *= FNV_PRIME; + ++p; + } + + return hash; +} + +/* + * Hashes a path + * + * @path: Path to hash. + * + * Returns 0 on failure, non-zero return values + * are valid. + */ +size_t +vfs_hash_path(const char *path) +{ + char *name = NULL; + size_t i = 0, hash = 0; + + if (strcmp(path, "/") == 0 || !vfs_is_valid_path(path)) { + return 0; + } else if (*path != '/') { + return 0; + } + + do { + name = vfs_get_fname_at(path, i++); + if (name != NULL) + hash += vfs_hash(name); + } while (name != NULL); + + return hash; +} + + +/* + * This function checks if a path is valid. + * + * @path: Path to check. + * + * Returns true if valid, otherwise false. + */ +bool +vfs_is_valid_path(const char *path) +{ + const char *ptr = path; + char c; + + while (*ptr != '\0') { + c = *(ptr++); + switch (c) { + case '/': + case '-': + case '_': + /* Valid char, can continue */ + continue; + default: + /* + * This could be an alphabetical or "numeric" char which + * is valid. We want to handle this too. To make things + * easier we'll OR the char by 0x20 to convert it to + * lowercase if it is alphabetical. + */ + c |= 0x20; + if (c >= 'a' && c <= 'z') + continue; + else if (c >= '0' && c <= '9') + continue; + + /* We got an invalid char */ + return false; + } + } + + return true; +} + +/* + * Allocates a vnode + * + * @vnode: Pointer to vnode pointer where newly allocated + * vnode will be stored. + * + * @mp: Mountpoint this vnode is associated with. + * @type: Vnode type. + * + * This function will return 0 upon success and < 0 on failure. + */ +int +vfs_alloc_vnode(struct vnode **vnode, struct mount *mp, int type) +{ + struct vnode *new_vnode = dynalloc(sizeof(struct vnode)); + + if (new_vnode == NULL) { + return -ENOMEM; + } + + memset(new_vnode, 0, sizeof(struct vnode)); + new_vnode->type = type; + new_vnode->mp = mp; + + *vnode = new_vnode; + return 0; +} + +/* + * This function mounts a `mount' structure + * at a specific path. + * + * @mp_out: Where to store copy of new mountpoint (NULL if none) + * @path: Path to mount on. + * @mnt_flags: Mount flags (MNT_* from sys/mount.h) + * + * Returns 0 upon success, otherwise a < 0 value. + * + * XXX: This function assumes the mountpoint has its mount + * routine set in its vfsops. + */ +int +vfs_mount(struct mount **mp_out, const char *path, int mnt_flags) +{ + struct mount *mp; + int cache_status; + + mp = dynalloc(sizeof(struct mount)); + if (mp == NULL) { + return -ENOMEM; + } + + mp->flags = mnt_flags; + cache_status = vfs_cache_mp(mp, path); + + if (cache_status != 0) { + return cache_status; + } + + *mp_out = mp; + return 0; +} -- cgit v1.2.3