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实现了打开、关闭、读取文件的功能

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fslongjin
2022-04-27 20:49:10 +08:00
parent 966d67fcde
commit b3ad8405a4
10 changed files with 258 additions and 105 deletions
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115
kernel/filesystem/fat32/fat32.c
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@ -4,6 +4,7 @@
#include <filesystem/MBR.h>
#include <process/spinlock.h>
#include <mm/slab.h>
#include <common/errno.h>
struct vfs_super_block_operations_t fat32_sb_ops;
struct vfs_dir_entry_operations_t fat32_dEntry_ops;
@ -30,7 +31,7 @@ struct vfs_superblock_t *fat32_register_partition(uint8_t ahci_ctrl_num, uint8_t
uint8_t buf[512] = {0};
// 读取文件系统的boot扇区
ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, DPT->DPTE[part_num].starting_LBA, 1, (uint64_t)&buf, ahci_ctrl_num, ahci_port_num);
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, DPT->DPTE[part_num].starting_LBA, 1, (uint64_t)&buf, ahci_ctrl_num, ahci_port_num);
// 挂载文件系统到vfs
return vfs_mount_fs("FAT32", (void *)(&DPT->DPTE[part_num]), VFS_DPT_MBR, buf, ahci_ctrl_num, ahci_port_num, part_num);
@ -47,17 +48,17 @@ uint32_t fat32_read_FAT_entry(fat32_sb_info_t *fsbi, uint32_t cluster)
{
// 计算每个扇区内含有的FAT表项数
// FAT每项4bytes
uint32_t fat_ent_per_sec = (fsbi->bootsector.BPB_BytesPerSec >> 2); // 该值应为2的n次幂
uint32_t fat_ent_per_sec = (fsbi->bytes_per_sec >> 2); // 该值应为2的n次幂
uint32_t buf[256];
memset(buf, 0, fsbi->bootsector.BPB_BytesPerSec);
memset(buf, 0, fsbi->bytes_per_sec);
// 读取一个sector的数据，
ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)&buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
// 返回下一个fat表项的值（也就是下一个cluster）
return buf[cluster & (fat_ent_per_sec - 1)] & 0x0fffffff;
;
}
/**
@ -76,14 +77,14 @@ uint32_t fat32_write_FAT_entry(fat32_sb_info_t *fsbi, uint32_t cluster, uint32_t
uint32_t buf[256];
memset(buf, 0, fsbi->bootsector.BPB_BytesPerSec);
ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)&buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
buf[cluster & (fat_ent_per_sec - 1)] = (buf[cluster & (fat_ent_per_sec - 1)] & 0xf0000000) | (value & 0x0fffffff);
// 向FAT1和FAT2写入数据
ahci_operation.transfer(ATA_CMD_WRITE_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)&buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
ahci_operation.transfer(ATA_CMD_WRITE_DMA_EXT, fsbi->FAT2_base_sector + (cluster / fat_ent_per_sec), 1,
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, fsbi->FAT2_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)&buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
return 0;
@ -120,8 +121,8 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
// kdebug("sector=%d",sector);
// 读取父目录项的起始簇数据
ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
// ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, sector, fat32_part_info[part_id].bootsector.BPB_SecPerClus, (uint64_t)buf, fat32_part_info[part_id].ahci_ctrl_num, fat32_part_info[part_id].ahci_port_num);
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
// ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, sector, fat32_part_info[part_id].bootsector.BPB_SecPerClus, (uint64_t)buf, fat32_part_info[part_id].ahci_ctrl_num, fat32_part_info[part_id].ahci_port_num);
tmp_dEntry = (struct fat32_Directory_t *)buf;
@ -344,7 +345,6 @@ find_lookup_success:; // 找到目标dentry
return dest_dentry;
}
/**
* @brief 创建fat32文件系统的超级块
*
@ -396,7 +396,7 @@ struct vfs_superblock_t *fat32_read_superblock(void *DPTE, uint8_t DPT_type, voi
// fsinfo扇区的信息
memset(&fsbi->fsinfo, 0, sizeof(struct fat32_FSInfo_t));
ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, MBR_DPTE->starting_LBA + fbs->BPB_FSInfo, 1, (uint64_t)&fsbi->fsinfo, ahci_ctrl_num, ahci_port_num);
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, MBR_DPTE->starting_LBA + fbs->BPB_FSInfo, 1, (uint64_t)&fsbi->fsinfo, ahci_ctrl_num, ahci_port_num);
printk_color(BLUE, BLACK, "FAT32 FSInfo\n\tFSI_LeadSig:%#018lx\n\tFSI_StrucSig:%#018lx\n\tFSI_Free_Count:%#018lx\n", fsbi->fsinfo.FSI_LeadSig, fsbi->fsinfo.FSI_StrucSig, fsbi->fsinfo.FSI_Free_Count);
// 初始化超级块的dir entry
@ -485,7 +485,7 @@ void fat32_write_inode(struct vfs_index_node_t *inode)
uint8_t *buf = (uint8_t *)kmalloc(fsbi->bytes_per_clus, 0);
memset(buf, 0, sizeof(fsbi->bytes_per_clus));
ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, fLBA, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fLBA, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
// 计算目标dEntry所在的位置
struct fat32_Directory_t *fdEntry = (struct fat32_Directory_t *)((uint64_t)buf + finode->dEntry_location_clus_offset);
@ -496,7 +496,7 @@ void fat32_write_inode(struct vfs_index_node_t *inode)
fdEntry->DIR_FstClusHI = (finode->first_clus >> 16) | (fdEntry->DIR_FstClusHI & 0xf000);
// 将dir entry写回磁盘
ahci_operation.transfer(ATA_CMD_WRITE_DMA_EXT, fLBA, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, fLBA, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
kfree(buf);
}
@ -546,14 +546,95 @@ long fat32_open(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr)
// todo: close
long fat32_close(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr)
{
return VFS_SUCCESS;
}
// todo: read
long fat32_read(struct vfs_file_t *file_ptr, char *buf, uint64_t buf_size, long *position)
/**
* @brief 从fat32文件系统读取数据
*
* @param file_ptr 文件描述符
* @param buf 输出缓冲区
* @param count 要读取的字节数
* @param position 文件指针位置
* @return long 执行成功：传输的字节数量 执行失败：错误码（小于0）
*/
long fat32_read(struct vfs_file_t *file_ptr, char *buf, uint64_t count, long *position)
{
struct fat32_inode_info_t *finode = (struct fat32_inode_info_t *)(file_ptr->dEntry->dir_inode->private_inode_info);
fat32_sb_info_t *fsbi = (fat32_sb_info_t *)(file_ptr->dEntry->dir_inode->sb->private_sb_info);
// First cluster num of the file
uint64_t cluster = finode->first_clus;
// kdebug("fsbi->bytes_per_clus=%d", fsbi->bytes_per_clus);
// clus offset in file
uint64_t total_clus_of_file = (*position) / fsbi->bytes_per_clus;
// bytes offset in clus
uint64_t bytes_offset = (*position) % fsbi->bytes_per_clus;
if (!cluster)
return -EFAULT;
// find the actual cluster on disk of the specified position
for (int i = 0; i < total_clus_of_file; ++i)
cluster = fat32_read_FAT_entry(fsbi, cluster);
// 如果需要读取的数据边界大于文件大小
if (*position + count > file_ptr->dEntry->dir_inode->file_size)
count = file_ptr->dEntry->dir_inode->file_size - *position;
// 剩余还需要传输的字节数量
uint64_t bytes_remain = count;
// alloc buffer memory space for ahci transfer
void *tmp_buffer = kmalloc(fsbi->bytes_per_clus, 0);
int64_t retval = 0;
do
{
memset(tmp_buffer, 0, fsbi->bytes_per_clus);
uint64_t sector = fsbi->first_data_sector + (cluster - 2) * fsbi->sec_per_clus;
// 读取一个簇的数据
int errno = ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)tmp_buffer, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
if (errno != AHCI_SUCCESS)
{
kerror("FAT32 FS(read) error!");
retval = -EIO;
break;
}
int64_t step_trans_len = 0; // 当前循环传输的字节数
if (bytes_remain > (fsbi->bytes_per_clus - bytes_offset))
step_trans_len = (fsbi->bytes_per_clus - bytes_offset);
else
step_trans_len = bytes_remain;
if (((uint64_t)buf) < USER_MAX_LINEAR_ADDR)
copy_to_user(buf, tmp_buffer + bytes_offset, step_trans_len);
else
memcpy(buf, tmp_buffer, step_trans_len);
bytes_remain -= step_trans_len;
buf += step_trans_len;
bytes_offset -= bytes_offset;
*position += step_trans_len; // 更新文件指针
cluster = fat32_read_FAT_entry(fsbi, cluster);
} while (bytes_remain && (cluster < 0x0ffffff8) && cluster != 0);
kfree(tmp_buffer);
if(!bytes_remain)
retval = count;
return retval;
}
// todo: write
long fat32_write(struct vfs_file_t *file_ptr, char *buf, uint64_t buf_size, long *position)
long fat32_write(struct vfs_file_t *file_ptr, char *buf, uint64_t count, long *position)
{
}
// todo: lseek