diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/include/kernel/filesystem/devfs/filesystem.hpp | 4 | ||||
| -rw-r--r-- | kernel/include/kernel/filesystem/ext2/filesystem.hpp | 4 | ||||
| -rw-r--r-- | kernel/include/kernel/filesystem/filesystem.hpp | 12 | ||||
| -rw-r--r-- | kernel/include/kernel/filesystem/mount.hpp | 10 | ||||
| -rw-r--r-- | kernel/include/kernel/filesystem/mount_table.hpp | 21 | ||||
| -rw-r--r-- | kernel/include/kernel/filesystem/rootfs/filesystem.hpp | 4 | ||||
| -rw-r--r-- | kernel/include/kernel/filesystem/vfs.hpp | 23 | ||||
| -rw-r--r-- | kernel/src/filesystem/devfs/filesystem.cpp | 5 | ||||
| -rw-r--r-- | kernel/src/filesystem/ext2/filesystem.cpp | 12 | ||||
| -rw-r--r-- | kernel/src/filesystem/filesystem.cpp | 6 | ||||
| -rw-r--r-- | kernel/src/filesystem/mount.cpp | 9 | ||||
| -rw-r--r-- | kernel/src/filesystem/mount_table.cpp | 69 | ||||
| -rw-r--r-- | kernel/src/filesystem/rootfs/filesystem.cpp | 4 | ||||
| -rw-r--r-- | kernel/src/filesystem/vfs.cpp | 45 | ||||
| -rw-r--r-- | kernel/src/main.cpp | 3 |
15 files changed, 187 insertions, 44 deletions
diff --git a/kernel/include/kernel/filesystem/devfs/filesystem.hpp b/kernel/include/kernel/filesystem/devfs/filesystem.hpp index 60c39cf..137eca3 100644 --- a/kernel/include/kernel/filesystem/devfs/filesystem.hpp +++ b/kernel/include/kernel/filesystem/devfs/filesystem.hpp @@ -24,9 +24,9 @@ namespace kernel::filesystem::devfs /** @brief Initializes the devfs instance and builds the device inode table. @param device Backing device passed by the generic filesystem interface (not required by devfs). - @return 0 on success, -1 on failure. + @return The result of the mount operation. */ - auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override; + auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> operation_result override; /** @brief Looks up an inode by @p name within a @p parent directory. diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp index 32374dc..65324c8 100644 --- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp +++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp @@ -27,9 +27,9 @@ namespace kernel::filesystem::ext2 /** @brief Initializes the ext2 filesystem with the given @p device. @param device The device to mount. - @return 0 on success, negative error code on failure. + @return The result of the mount operation. */ - auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override; + auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> operation_result override; /** @brief Looks up an inode by @p name within a @p parent directory. diff --git a/kernel/include/kernel/filesystem/filesystem.hpp b/kernel/include/kernel/filesystem/filesystem.hpp index f855380..ef6929a 100644 --- a/kernel/include/kernel/filesystem/filesystem.hpp +++ b/kernel/include/kernel/filesystem/filesystem.hpp @@ -18,6 +18,14 @@ namespace kernel::filesystem */ struct filesystem { + enum class operation_result : int + { + success = 0, + invalid_magic_number = -1, + invalid_root_inode = -2, + unmount_failed = -3 + }; + /** @brief Virtual destructor for the filesystem. */ @@ -37,9 +45,9 @@ namespace kernel::filesystem /** @brief Initializes the filesystem with the given @p device. @param device The device to mount. - @return 0 on success, or a negative error code on failure. + @return The result of the mount operation. */ - virtual auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int; + virtual auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> operation_result; /** @brief Looks up a child inode within the given @p parent inode with the specified @p name. This method must be diff --git a/kernel/include/kernel/filesystem/mount.hpp b/kernel/include/kernel/filesystem/mount.hpp index 3e3c69f..0ac6b2f 100644 --- a/kernel/include/kernel/filesystem/mount.hpp +++ b/kernel/include/kernel/filesystem/mount.hpp @@ -24,9 +24,11 @@ namespace kernel::filesystem @param root_dentry The root dentry of the mounted filesystem. @param fs The filesystem instance being mounted. @param mount_path The path at which the filesystem is mounted. + @param parent_mount The parent mount that this mount is attached beneath. */ mount(kstd::shared_ptr<dentry> const & mount_dentry, kstd::shared_ptr<dentry> const & root_dentry, - kstd::shared_ptr<filesystem> const & fs, std::string_view mount_path); + kstd::shared_ptr<filesystem> const & fs, std::string_view mount_path, + kstd::shared_ptr<mount> const & parent_mount); /** @brief Get the dentry where the filesystem is mounted. @@ -48,11 +50,17 @@ namespace kernel::filesystem */ [[nodiscard]] auto get_mount_path() const -> std::string_view; + /** + @brief Get the parent mount that this mount was attached beneath. + */ + [[nodiscard]] auto get_parent_mount() const -> kstd::shared_ptr<mount> const &; + private: kstd::string m_mount_path; kstd::shared_ptr<dentry> m_mount_dentry; kstd::shared_ptr<dentry> m_root_dentry; kstd::shared_ptr<filesystem> m_filesystem{}; + kstd::shared_ptr<mount> m_parent_mount{}; }; } // namespace kernel::filesystem diff --git a/kernel/include/kernel/filesystem/mount_table.hpp b/kernel/include/kernel/filesystem/mount_table.hpp index a8ef59e..a5cdde6 100644 --- a/kernel/include/kernel/filesystem/mount_table.hpp +++ b/kernel/include/kernel/filesystem/mount_table.hpp @@ -16,10 +16,27 @@ namespace kernel::filesystem struct mount_table { /** + @brief Results for mount table operations. + */ + enum class operation_result : int + { + removed = 0, + has_child_mounts = -1, + mount_not_found = -2 + }; + + /** @brief Adds a mount to the table. @param mount The mount to add. */ - void add_mount(kstd::shared_ptr<mount> const & mount); + auto add_mount(kstd::shared_ptr<mount> const & mount) -> void; + + /** + @brief Removes the topmost mount at the given @p path. + @param path The mount path to remove. + @return The result of the removal operation. + */ + [[nodiscard]] auto remove_mount(std::string_view path) -> operation_result; /** @brief Finds the mount with the longest prefix matching the given @p path. This method is used to determine which @@ -30,6 +47,8 @@ namespace kernel::filesystem [[nodiscard]] auto find_longest_prefix_mount(std::string_view path) const -> kstd::shared_ptr<mount>; private: + [[nodiscard]] auto has_child_mounts(kstd::shared_ptr<mount> const & parent_mount) const -> bool; + kstd::vector<kstd::shared_ptr<mount>> m_mounts; }; } // namespace kernel::filesystem diff --git a/kernel/include/kernel/filesystem/rootfs/filesystem.hpp b/kernel/include/kernel/filesystem/rootfs/filesystem.hpp index b7e7c6f..0155c41 100644 --- a/kernel/include/kernel/filesystem/rootfs/filesystem.hpp +++ b/kernel/include/kernel/filesystem/rootfs/filesystem.hpp @@ -25,9 +25,9 @@ namespace kernel::filesystem::rootfs /** @brief Initializes the rootfs filesystem with the given @p device. @param device The device to mount (not required by rootfs). - @return 0 on success, negative error code on failure. + @return The result of the mount operation. */ - auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override; + auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> operation_result override; /** @brief Looks up an inode by @p name within a @p parent directory. diff --git a/kernel/include/kernel/filesystem/vfs.hpp b/kernel/include/kernel/filesystem/vfs.hpp index 2d05765..4dd2a83 100644 --- a/kernel/include/kernel/filesystem/vfs.hpp +++ b/kernel/include/kernel/filesystem/vfs.hpp @@ -21,6 +21,18 @@ namespace kernel::filesystem struct vfs { /** + @brief Results for VFS operations. + */ + enum class operation_result : int + { + success = 0, + invalid_path = -1, + mount_point_not_found = -2, + filesystem_null = -3, + unmount_failed = -4 + }; + + /** @brief Initialize the virtual filesystem. @warning Panics if the VFS has already been initialized. */ @@ -49,9 +61,16 @@ namespace kernel::filesystem @brief Mount a @p filesystem at a specific @p path. @param path The path where the filesystem should be mounted. @param filesystem The filesystem to mount. - @return 0 on success, or a negative error code on failure. + @return The result of the mount operation. + */ + auto do_mount(std::string_view path, kstd::shared_ptr<filesystem> const & filesystem) -> operation_result; + + /** + @brief Unmount the filesystem mounted at the specified @p path. + @param path The path where the filesystem is mounted. + @return The result of the unmount operation. */ - auto do_mount(std::string_view path, kstd::shared_ptr<filesystem> const & filesystem) -> int; + auto unmount(std::string_view path) -> operation_result; private: vfs() = default; diff --git a/kernel/src/filesystem/devfs/filesystem.cpp b/kernel/src/filesystem/devfs/filesystem.cpp index 9043ac5..03b4218 100644 --- a/kernel/src/filesystem/devfs/filesystem.cpp +++ b/kernel/src/filesystem/devfs/filesystem.cpp @@ -1,6 +1,7 @@ #include "kernel/filesystem/devfs/filesystem.hpp" #include "kapi/devices/device.hpp" + #include "kernel/devices/storage/management.hpp" #include "kernel/filesystem/devfs/inode.hpp" #include "kernel/filesystem/device_inode.hpp" @@ -13,12 +14,12 @@ namespace kernel::filesystem::devfs { - auto filesystem::mount(kstd::shared_ptr<kapi::devices::device> const &) -> int + auto filesystem::mount(kstd::shared_ptr<kapi::devices::device> const &) -> operation_result { m_root_inode = kstd::make_shared<inode>(); build_device_inode_table(); - return 0; + return operation_result::success; } auto filesystem::lookup(kstd::shared_ptr<kernel::filesystem::inode> const & parent, std::string_view name) diff --git a/kernel/src/filesystem/ext2/filesystem.cpp b/kernel/src/filesystem/ext2/filesystem.cpp index 7ee1072..6d5960e 100644 --- a/kernel/src/filesystem/ext2/filesystem.cpp +++ b/kernel/src/filesystem/ext2/filesystem.cpp @@ -36,10 +36,6 @@ namespace kernel::filesystem::ext2 constexpr uint16_t S_IFREG = 0x8000; constexpr uint16_t S_IFDIR = 0x4000; - // Error codes - constexpr int INVALID_MAGIC_NUMBER = -1; - constexpr int INVALID_ROOT_INODE = -2; - auto S_ISREG(uint16_t mode) -> bool { return (mode & S_IFMT) == S_IFREG; @@ -51,7 +47,7 @@ namespace kernel::filesystem::ext2 } } // namespace - auto filesystem::mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int + auto filesystem::mount(kstd::shared_ptr<kapi::devices::device> const & device) -> operation_result { kernel::filesystem::filesystem::mount(device); @@ -59,7 +55,7 @@ namespace kernel::filesystem::ext2 if (m_superblock.magic != MAGIC_NUMBER) { - return INVALID_MAGIC_NUMBER; + return operation_result::invalid_magic_number; } auto const block_size = get_block_size(); @@ -77,9 +73,9 @@ namespace kernel::filesystem::ext2 if (!m_root_inode || !m_root_inode->is_directory()) { - return INVALID_ROOT_INODE; + return operation_result::invalid_root_inode; } - return 0; + return operation_result::success; } auto filesystem::lookup(kstd::shared_ptr<kernel::filesystem::inode> const & parent, std::string_view name) diff --git a/kernel/src/filesystem/filesystem.cpp b/kernel/src/filesystem/filesystem.cpp index b08b520..da2838d 100644 --- a/kernel/src/filesystem/filesystem.cpp +++ b/kernel/src/filesystem/filesystem.cpp @@ -30,7 +30,7 @@ namespace kernel::filesystem for (auto & factory : filesystem_factories) { auto fs = factory(); - if (fs->mount(device) == 0) + if (fs->mount(device) == operation_result::success) { return fs; } @@ -39,11 +39,11 @@ namespace kernel::filesystem return nullptr; } - auto filesystem::mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int + auto filesystem::mount(kstd::shared_ptr<kapi::devices::device> const & device) -> operation_result { // TODO BA-FS26 maybe check if device is null and panic here already? m_device = device; - return 0; + return operation_result::success; } auto filesystem::root_inode() const -> kstd::shared_ptr<inode> const & diff --git a/kernel/src/filesystem/mount.cpp b/kernel/src/filesystem/mount.cpp index a6d2f7e..d165385 100644 --- a/kernel/src/filesystem/mount.cpp +++ b/kernel/src/filesystem/mount.cpp @@ -13,11 +13,13 @@ namespace kernel::filesystem { mount::mount(kstd::shared_ptr<dentry> const & mount_dentry, kstd::shared_ptr<dentry> const & root_dentry, - kstd::shared_ptr<filesystem> const & fs, std::string_view mount_path) + kstd::shared_ptr<filesystem> const & fs, std::string_view mount_path, + kstd::shared_ptr<mount> const & parent_mount) : m_mount_path(mount_path) , m_mount_dentry(mount_dentry) , m_root_dentry(root_dentry) , m_filesystem(fs) + , m_parent_mount(parent_mount) { if (!m_filesystem) { @@ -44,4 +46,9 @@ namespace kernel::filesystem { return m_mount_path.view(); } + + auto mount::get_parent_mount() const -> kstd::shared_ptr<mount> const & + { + return m_parent_mount; + } } // namespace kernel::filesystem
\ No newline at end of file diff --git a/kernel/src/filesystem/mount_table.cpp b/kernel/src/filesystem/mount_table.cpp index 195f48a..3b1dee3 100644 --- a/kernel/src/filesystem/mount_table.cpp +++ b/kernel/src/filesystem/mount_table.cpp @@ -1,17 +1,83 @@ #include "kernel/filesystem/mount_table.hpp" +#include "kernel/filesystem/dentry.hpp" #include "kernel/filesystem/mount.hpp" #include <kstd/memory> +#include <kstd/vector> +#include <algorithm> #include <cstddef> +#include <ranges> #include <string_view> namespace kernel::filesystem { + namespace + { + auto is_descendant_of(kstd::shared_ptr<mount> const & candidate, kstd::shared_ptr<mount> const & ancestor) -> bool + { + for (auto current = candidate; current; current = current->get_parent_mount()) + { + if (current == ancestor) + { + return true; + } + } + + return false; + } + + auto is_strict_prefix(std::string_view prefix, std::string_view path) -> bool + { + return prefix != "/" && path.starts_with(prefix) && path.size() > prefix.size() && path[prefix.size()] == '/'; + } + + auto is_visible_mount(kstd::shared_ptr<mount> const & candidate, + kstd::vector<kstd::shared_ptr<mount>> const & mounts) -> bool + { + return std::ranges::none_of(mounts, [&](auto const & other) { + return other != candidate && is_strict_prefix(other->get_mount_path(), candidate->get_mount_path()) && + !is_descendant_of(candidate, other); + }); + } + } // namespace + + auto mount_table::has_child_mounts(kstd::shared_ptr<mount> const & parent_mount) const -> bool + { + return std::ranges::any_of( + m_mounts, [&parent_mount](auto const & mount) { return mount->get_parent_mount() == parent_mount; }); + } + void mount_table::add_mount(kstd::shared_ptr<mount> const & mount) { m_mounts.push_back(mount); + if (auto mount_dentry = mount->get_mount_dentry()) + { + mount_dentry->set_flag(dentry::dentry_flags::dcache_mounted); + } + } + + auto mount_table::remove_mount(std::string_view path) -> operation_result + { + auto mount_it = std::ranges::find_if(std::ranges::reverse_view(m_mounts), [&](auto const & mount) { + return mount->get_mount_path() == path && is_visible_mount(mount, m_mounts); + }); + + if (mount_it == std::ranges::reverse_view(m_mounts).end()) + { + return operation_result::mount_not_found; + } + + auto const & mount = *mount_it; + if (has_child_mounts(mount)) + { + return operation_result::has_child_mounts; + } + + mount->get_mount_dentry()->unset_flag(dentry::dentry_flags::dcache_mounted); + m_mounts.erase(std::ranges::find(m_mounts, mount)); + return operation_result::removed; } auto mount_table::find_longest_prefix_mount(std::string_view path) const -> kstd::shared_ptr<mount> @@ -25,8 +91,9 @@ namespace kernel::filesystem // /a/b/c should match /a/b but not /a/bb or /a/b/c/d, / should match everything bool is_prefix = path.starts_with(mp) && (mp == "/" || path.size() == mp.size() || path[mp.size()] == '/'); + bool visible = is_visible_mount(mount, m_mounts); - if (is_prefix && mp.size() >= best_len) + if (is_prefix && visible && mp.size() >= best_len) { mount_with_longest_prefix = mount; best_len = mp.size(); diff --git a/kernel/src/filesystem/rootfs/filesystem.cpp b/kernel/src/filesystem/rootfs/filesystem.cpp index a7c746e..dffef99 100644 --- a/kernel/src/filesystem/rootfs/filesystem.cpp +++ b/kernel/src/filesystem/rootfs/filesystem.cpp @@ -11,13 +11,13 @@ namespace kernel::filesystem::rootfs { - auto filesystem::mount(kstd::shared_ptr<kapi::devices::device> const &) -> int + auto filesystem::mount(kstd::shared_ptr<kapi::devices::device> const &) -> operation_result { auto rfs_inode = kstd::make_shared<inode>(); rfs_inode->add_child("dev"); m_root_inode = rfs_inode; - return 0; + return operation_result::success; } auto filesystem::lookup(kstd::shared_ptr<kernel::filesystem::inode> const & parent, std::string_view name) diff --git a/kernel/src/filesystem/vfs.cpp b/kernel/src/filesystem/vfs.cpp index 2578036..45ae053 100644 --- a/kernel/src/filesystem/vfs.cpp +++ b/kernel/src/filesystem/vfs.cpp @@ -7,6 +7,7 @@ #include "kernel/filesystem/devfs/filesystem.hpp" #include "kernel/filesystem/filesystem.hpp" #include "kernel/filesystem/mount.hpp" +#include "kernel/filesystem/mount_table.hpp" #include "kernel/filesystem/open_file_description.hpp" #include "kernel/filesystem/rootfs/filesystem.hpp" @@ -21,11 +22,6 @@ namespace kernel::filesystem namespace { constinit auto static active_vfs = std::optional<vfs>{}; - - // Error codes - constexpr int INVALID_PATH = -1; - constexpr int MOUNT_POINT_NOT_FOUND = -2; - constexpr int FILESYSTEM_NULL = -3; } // namespace auto vfs::init() -> void @@ -45,7 +41,7 @@ namespace kernel::filesystem root_fs->mount(nullptr); auto root_fs_root_dentry = kstd::make_shared<dentry>(nullptr, root_fs->root_inode()); - m_mount_table.add_mount(kstd::make_shared<mount>(nullptr, root_fs_root_dentry, root_fs, "")); + m_mount_table.add_mount(kstd::make_shared<mount>(nullptr, root_fs_root_dentry, root_fs, "", nullptr)); auto storage_mgmt = devices::storage::management::get(); if (auto boot_device = storage_mgmt.determine_boot_device()) @@ -79,36 +75,55 @@ namespace kernel::filesystem return nullptr; } - // TODO BA-FS26 implement unmount - auto vfs::do_mount(std::string_view path, kstd::shared_ptr<filesystem> const & filesystem) -> int + auto vfs::do_mount(std::string_view path, kstd::shared_ptr<filesystem> const & filesystem) -> operation_result { if (!filesystem) { - return FILESYSTEM_NULL; + return operation_result::filesystem_null; } if (path.empty() || path.front() != '/' || (path.size() > 1 && path.back() == '/')) { - return INVALID_PATH; + return operation_result::invalid_path; } if (auto mount_point_dentry = resolve_path(path)) { do_mount_internal(path, mount_point_dentry, filesystem); - return 0; + return operation_result::success; + } + + return operation_result::mount_point_not_found; + } + + auto vfs::unmount(std::string_view path) -> operation_result + { + if (path.empty() || path.front() != '/' || (path.size() > 1 && path.back() == '/')) + { + return operation_result::invalid_path; + } + + auto remove_result = m_mount_table.remove_mount(path); + if (remove_result == mount_table::operation_result::removed) + { + return operation_result::success; + } + + if (remove_result == mount_table::operation_result::has_child_mounts) + { + return operation_result::unmount_failed; } - return MOUNT_POINT_NOT_FOUND; + return operation_result::mount_point_not_found; } auto vfs::do_mount_internal(std::string_view path, kstd::shared_ptr<dentry> const & mount_point_dentry, kstd::shared_ptr<filesystem> const & fs) -> void { - // TODO BA-FS26 check if mount point is already mounted and handle it (unmount old fs, fail, etc.) + auto parent_mount = m_mount_table.find_longest_prefix_mount(path); auto new_fs_root = kstd::make_shared<dentry>(mount_point_dentry, fs->root_inode()); - auto new_mount = kstd::make_shared<mount>(mount_point_dentry, new_fs_root, fs, path); + auto new_mount = kstd::make_shared<mount>(mount_point_dentry, new_fs_root, fs, path, parent_mount); m_mount_table.add_mount(new_mount); - mount_point_dentry->set_flag(dentry::dentry_flags::dcache_mounted); } auto vfs::resolve_path(std::string_view path) -> kstd::shared_ptr<dentry> diff --git a/kernel/src/main.cpp b/kernel/src/main.cpp index 1893b84..1d73e20 100644 --- a/kernel/src/main.cpp +++ b/kernel/src/main.cpp @@ -145,6 +145,9 @@ auto test_file_lookup() -> void vfs.do_mount("/enclosures/aquarium", new_filesystem); read_and_write_file("/enclosures/aquarium/closed.txt"); read_and_write_file("/enclosures/aquarium/information/info_2.txt"); + + vfs.unmount("/enclosures/aquarium"); + read_and_write_file("/enclosures/aquarium/tank_1/fish_4.txt"); } auto run_test_code() -> void |