Kernel/LibC: Rework dirent structure

dirent now contains statically sized d_name. This allows using
sizeof on the name and dirent properly, which some programs seem
to be using.
This commit is contained in:
Bananymous 2024-05-22 20:17:39 +03:00
parent e77de1804f
commit 0af74fccda
13 changed files with 52 additions and 96 deletions

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@ -1,21 +0,0 @@
#pragma once
#include <dirent.h>
namespace Kernel::API
{
struct DirectoryEntry
{
size_t rec_len { 0 };
struct dirent dirent;
DirectoryEntry* next() const { return (DirectoryEntry*)((uintptr_t)this + rec_len); }
};
struct DirectoryEntryList
{
size_t entry_count { 0 };
DirectoryEntry array[];
};
}

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@ -31,7 +31,7 @@ namespace Kernel
protected:
virtual BAN::ErrorOr<BAN::RefPtr<Inode>> find_inode_impl(BAN::StringView) override;
virtual BAN::ErrorOr<void> list_next_inodes_impl(off_t, DirectoryEntryList*, size_t) override;
virtual BAN::ErrorOr<size_t> list_next_inodes_impl(off_t, struct dirent*, size_t) override;
virtual BAN::ErrorOr<void> create_file_impl(BAN::StringView, mode_t, uid_t, gid_t) override;
virtual BAN::ErrorOr<void> create_directory_impl(BAN::StringView, mode_t, uid_t, gid_t) override;
virtual BAN::ErrorOr<void> unlink_impl(BAN::StringView) override;

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@ -7,11 +7,11 @@
#include <BAN/Vector.h>
#include <BAN/WeakPtr.h>
#include <kernel/API/DirectoryEntry.h>
#include <kernel/Credentials.h>
#include <kernel/Debug.h>
#include <kernel/Lock/Mutex.h>
#include <dirent.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <time.h>
@ -19,8 +19,6 @@
namespace Kernel
{
using namespace API;
class FileBackedRegion;
class SharedFileData;
@ -92,7 +90,7 @@ namespace Kernel
// Directory API
BAN::ErrorOr<BAN::RefPtr<Inode>> find_inode(BAN::StringView);
BAN::ErrorOr<void> list_next_inodes(off_t, DirectoryEntryList*, size_t);
BAN::ErrorOr<size_t> list_next_inodes(off_t, struct dirent* list, size_t list_size);
BAN::ErrorOr<void> create_file(BAN::StringView, mode_t, uid_t, gid_t);
BAN::ErrorOr<void> create_directory(BAN::StringView, mode_t, uid_t, gid_t);
BAN::ErrorOr<void> unlink(BAN::StringView);
@ -127,7 +125,7 @@ namespace Kernel
// Directory API
virtual BAN::ErrorOr<BAN::RefPtr<Inode>> find_inode_impl(BAN::StringView) { return BAN::Error::from_errno(ENOTSUP); }
virtual BAN::ErrorOr<void> list_next_inodes_impl(off_t, DirectoryEntryList*, size_t) { return BAN::Error::from_errno(ENOTSUP); }
virtual BAN::ErrorOr<size_t> list_next_inodes_impl(off_t, struct dirent*, size_t) { return BAN::Error::from_errno(ENOTSUP); }
virtual BAN::ErrorOr<void> create_file_impl(BAN::StringView, mode_t, uid_t, gid_t) { return BAN::Error::from_errno(ENOTSUP); }
virtual BAN::ErrorOr<void> create_directory_impl(BAN::StringView, mode_t, uid_t, gid_t) { return BAN::Error::from_errno(ENOTSUP); }
virtual BAN::ErrorOr<void> unlink_impl(BAN::StringView) { return BAN::Error::from_errno(ENOTSUP); }

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@ -141,7 +141,7 @@ namespace Kernel
protected:
virtual BAN::ErrorOr<BAN::RefPtr<Inode>> find_inode_impl(BAN::StringView) override final;
virtual BAN::ErrorOr<void> list_next_inodes_impl(off_t, DirectoryEntryList*, size_t) override final;
virtual BAN::ErrorOr<size_t> list_next_inodes_impl(off_t, struct dirent*, size_t) override final;
virtual BAN::ErrorOr<void> create_file_impl(BAN::StringView, mode_t, uid_t, gid_t) override final;
virtual BAN::ErrorOr<void> create_directory_impl(BAN::StringView, mode_t, uid_t, gid_t) override final;
virtual BAN::ErrorOr<void> unlink_impl(BAN::StringView) override;

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@ -47,7 +47,7 @@ namespace Kernel
BAN::ErrorOr<size_t> read(int fd, BAN::ByteSpan);
BAN::ErrorOr<size_t> write(int fd, BAN::ConstByteSpan);
BAN::ErrorOr<void> read_dir_entries(int fd, DirectoryEntryList* list, size_t list_size);
BAN::ErrorOr<size_t> read_dir_entries(int fd, struct dirent* list, size_t list_len);
BAN::ErrorOr<BAN::StringView> path_of(int) const;
BAN::ErrorOr<BAN::RefPtr<Inode>> inode_of(int);

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@ -149,7 +149,7 @@ namespace Kernel
BAN::ErrorOr<void> mount(BAN::StringView source, BAN::StringView target);
BAN::ErrorOr<long> sys_readdir(int fd, DirectoryEntryList* buffer, size_t buffer_size);
BAN::ErrorOr<long> sys_readdir(int fd, struct dirent* list, size_t list_len);
BAN::ErrorOr<long> sys_mmap(const sys_mmap_t*);
BAN::ErrorOr<long> sys_munmap(void* addr, size_t len);

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@ -299,16 +299,13 @@ done:
m_fs.delete_inode(ino());
}
BAN::ErrorOr<void> Ext2Inode::list_next_inodes_impl(off_t offset, DirectoryEntryList* list, size_t list_size)
BAN::ErrorOr<size_t> Ext2Inode::list_next_inodes_impl(off_t offset, struct dirent* list, size_t list_size)
{
ASSERT(mode().ifdir());
ASSERT(offset >= 0);
if (static_cast<BAN::make_unsigned_t<decltype(offset)>>(offset) >= max_used_data_block_count())
{
list->entry_count = 0;
return {};
}
return 0;
// FIXME: can we actually assume directories have all their blocks allocated
const uint32_t block_index = fs_block_of_data_block_index(offset).value();
@ -318,26 +315,25 @@ done:
m_fs.read_block(block_index, block_buffer);
// First determine if we have big enough list
size_t entry_count = 0;
{
BAN::ConstByteSpan entry_span = block_buffer.span();
size_t needed_size = sizeof(DirectoryEntryList);
while (entry_span.size() >= sizeof(Ext2::LinkedDirectoryEntry))
{
auto& entry = entry_span.as<const Ext2::LinkedDirectoryEntry>();
if (entry.inode)
needed_size += sizeof(DirectoryEntry) + entry.name_len + 1;
entry_count++;
entry_span = entry_span.slice(entry.rec_len);
}
if (needed_size > list_size)
return BAN::Error::from_errno(EINVAL);
if (entry_count > list_size)
return BAN::Error::from_errno(ENOBUFS);
}
// Second fill the list
{
DirectoryEntry* ptr = list->array;
list->entry_count = 0;
dirent* dirp = list;
BAN::ConstByteSpan entry_span = block_buffer.span();
while (entry_span.size() >= sizeof(Ext2::LinkedDirectoryEntry))
@ -345,20 +341,16 @@ done:
auto& entry = entry_span.as<const Ext2::LinkedDirectoryEntry>();
if (entry.inode)
{
ptr->dirent.d_ino = entry.inode;
ptr->dirent.d_type = entry.file_type;
ptr->rec_len = sizeof(DirectoryEntry) + entry.name_len + 1;
memcpy(ptr->dirent.d_name, entry.name, entry.name_len);
ptr->dirent.d_name[entry.name_len] = '\0';
ptr = ptr->next();
list->entry_count++;
dirp->d_ino = entry.inode;
dirp->d_type = entry.file_type;
strncpy(dirp->d_name, entry.name, entry.name_len);
dirp++;
}
entry_span = entry_span.slice(entry.rec_len);
}
}
return {};
return entry_count;
}
static bool mode_has_valid_type(mode_t mode)

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@ -70,7 +70,7 @@ namespace Kernel
return find_inode_impl(name);
}
BAN::ErrorOr<void> Inode::list_next_inodes(off_t offset, DirectoryEntryList* list, size_t list_len)
BAN::ErrorOr<size_t> Inode::list_next_inodes(off_t offset, struct dirent* list, size_t list_len)
{
LockGuard _(m_mutex);
if (!mode().ifdir())

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@ -432,9 +432,9 @@ namespace Kernel
return BAN::RefPtr<Inode>(inode);
}
BAN::ErrorOr<void> TmpDirectoryInode::list_next_inodes_impl(off_t data_block_index, DirectoryEntryList* list, size_t list_len)
BAN::ErrorOr<size_t> TmpDirectoryInode::list_next_inodes_impl(off_t data_block_index, struct dirent* list, size_t list_len)
{
if (list_len < (size_t)blksize())
if (list_len == 0)
{
dprintln("buffer is too small");
return BAN::Error::from_errno(ENOBUFS);
@ -442,13 +442,12 @@ namespace Kernel
auto block_index = this->block_index(data_block_index);
list->entry_count = 0;
// if we reach a non-allocated block, it marks the end
if (!block_index.has_value())
return {};
return 0;
auto* dirp = list->array;
dirent* dirp = list;
size_t entry_count = 0;
const size_t byte_count = BAN::Math::min<size_t>(size() - data_block_index * blksize(), blksize());
m_fs.with_block_buffer(block_index.value(), [&](BAN::ByteSpan bytespan) {
@ -462,21 +461,21 @@ namespace Kernel
{
// TODO: dirents should be aligned
dirp->dirent.d_ino = entry.ino;
dirp->dirent.d_type = entry.type;
strncpy(dirp->dirent.d_name, entry.name, entry.name_len);
dirp->dirent.d_name[entry.name_len] = '\0';
dirp->rec_len = sizeof(DirectoryEntry) + entry.name_len + 1;
dirp = dirp->next();
entry_count++;
if (entry_count > list_len)
return;
list->entry_count++;
dirp->d_ino = entry.ino;
dirp->d_type = entry.type;
strncpy(dirp->d_name, entry.name, entry.name_len);
dirp++;
}
bytespan = bytespan.slice(entry.rec_len);
}
});
return {};
return entry_count;
}
BAN::ErrorOr<void> TmpDirectoryInode::create_file_impl(BAN::StringView name, mode_t mode, uid_t uid, gid_t gid)

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@ -351,15 +351,13 @@ namespace Kernel
return nwrite;
}
BAN::ErrorOr<void> OpenFileDescriptorSet::read_dir_entries(int fd, DirectoryEntryList* list, size_t list_size)
BAN::ErrorOr<size_t> OpenFileDescriptorSet::read_dir_entries(int fd, struct dirent* list, size_t list_len)
{
TRY(validate_fd(fd));
auto& open_file = m_open_files[fd];
if (!(open_file->flags & O_RDONLY))
return BAN::Error::from_errno(EACCES);
TRY(open_file->inode->list_next_inodes(open_file->offset, list, list_size));
open_file->offset++;
return {};
return TRY(open_file->inode->list_next_inodes(open_file->offset++, list, list_len));
}
BAN::ErrorOr<BAN::StringView> OpenFileDescriptorSet::path_of(int fd) const

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@ -1220,12 +1220,11 @@ namespace Kernel
return clean_poweroff(command);
}
BAN::ErrorOr<long> Process::sys_readdir(int fd, DirectoryEntryList* list, size_t list_size)
BAN::ErrorOr<long> Process::sys_readdir(int fd, struct dirent* list, size_t list_len)
{
LockGuard _(m_process_lock);
TRY(validate_pointer_access(list, list_size));
TRY(m_open_file_descriptors.read_dir_entries(fd, list, list_size));
return 0;
TRY(validate_pointer_access(list, sizeof(dirent) * list_len));
return TRY(m_open_file_descriptors.read_dir_entries(fd, list, list_len));
}
BAN::ErrorOr<long> Process::sys_setpwd(const char* path)

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@ -5,16 +5,14 @@
#include <sys/syscall.h>
#include <unistd.h>
#include <kernel/API/DirectoryEntry.h>
struct __DIR
{
int fd { -1 };
size_t entry_count { 0 };
size_t entry_index { 0 };
Kernel::API::DirectoryEntry* current { nullptr };
size_t buffer_size { 0 };
Kernel::API::DirectoryEntryList buffer[];
// FIXME: we should probably allocate entries dynamically
// based if syscall returns ENOBUFS
dirent entries[128];
};
int closedir(DIR* dirp)
@ -26,7 +24,6 @@ int closedir(DIR* dirp)
}
close(dirp->fd);
dirp->fd = -1;
free(dirp);
return 0;
@ -45,13 +42,13 @@ int dirfd(DIR* dirp)
DIR* fdopendir(int fd)
{
DIR* dirp = (DIR*)malloc(sizeof(DIR) + 4096);
DIR* dirp = (DIR*)malloc(sizeof(DIR));
if (dirp == nullptr)
return nullptr;
dirp->fd = fd;
dirp->current = nullptr;
dirp->buffer_size = 4096;
dirp->entry_count = 0;
dirp->entry_index = 0;
return dirp;
}
@ -73,20 +70,15 @@ struct dirent* readdir(DIR* dirp)
}
dirp->entry_index++;
if (dirp->current && dirp->entry_index < dirp->buffer->entry_count)
{
dirp->current = dirp->current->next();
return &dirp->current->dirent;
}
if (dirp->entry_index < dirp->entry_count)
return &dirp->entries[dirp->entry_index];
if (syscall(SYS_READ_DIR, dirp->fd, dirp->buffer, dirp->buffer_size) == -1)
return nullptr;
if (dirp->buffer->entry_count == 0)
long entry_count = syscall(SYS_READ_DIR, dirp->fd, dirp->entries, sizeof(dirp->entries) / sizeof(dirp->entries[0]));
if (entry_count <= 0)
return nullptr;
dirp->entry_count = entry_count;
dirp->entry_index = 0;
dirp->current = dirp->buffer->array;
return &dirp->current->dirent;
return &dirp->entries[0];
}

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@ -10,7 +10,6 @@ __BEGIN_DECLS
#define __need_ino_t
#include <sys/types.h>
struct __DIR;
typedef struct __DIR DIR;
#define DT_UNKNOWN 0
@ -26,7 +25,7 @@ struct dirent
{
ino_t d_ino; /* File serial number. */
unsigned char d_type; /* File type. One of DT_* definitions. */
char d_name[]; /* Filename string of entry. */
char d_name[256]; /* Filename string of entry. */
};
int alphasort(const struct dirent** d1, const struct dirent** d2);