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129 rader
5.8 KiB
129 rader
5.8 KiB
#ifndef __KERN_FS_SFS_SFS_H__
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#define __KERN_FS_SFS_SFS_H__
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#include <defs.h>
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#include <mmu.h>
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#include <list.h>
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#include <sem.h>
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#include <unistd.h>
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/*
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* Simple FS (SFS) definitions visible to ucore. This covers the on-disk format
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* and is used by tools that work on SFS volumes, such as mksfs.
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*/
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#define SFS_MAGIC 0x2f8dbe2a /* magic number for sfs */
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#define SFS_BLKSIZE PGSIZE /* size of block */
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#define SFS_NDIRECT 12 /* # of direct blocks in inode */
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#define SFS_MAX_INFO_LEN 31 /* max length of infomation */
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#define SFS_MAX_FNAME_LEN FS_MAX_FNAME_LEN /* max length of filename */
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#define SFS_MAX_FILE_SIZE (1024UL * 1024 * 128) /* max file size (128M) */
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#define SFS_BLKN_SUPER 0 /* block the superblock lives in */
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#define SFS_BLKN_ROOT 1 /* location of the root dir inode */
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#define SFS_BLKN_FREEMAP 2 /* 1st block of the freemap */
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/* # of bits in a block */
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#define SFS_BLKBITS (SFS_BLKSIZE * CHAR_BIT)
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/* # of entries in a block */
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#define SFS_BLK_NENTRY (SFS_BLKSIZE / sizeof(uint32_t))
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/* file types */
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#define SFS_TYPE_INVAL 0 /* Should not appear on disk */
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#define SFS_TYPE_FILE 1
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#define SFS_TYPE_DIR 2
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#define SFS_TYPE_LINK 3
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/*
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* On-disk superblock
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*/
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struct sfs_super {
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uint32_t magic; /* magic number, should be SFS_MAGIC */
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uint32_t blocks; /* # of blocks in fs */
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uint32_t unused_blocks; /* # of unused blocks in fs */
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char info[SFS_MAX_INFO_LEN + 1]; /* infomation for sfs */
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};
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/* inode (on disk) */
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struct sfs_disk_inode {
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uint32_t size; /* size of the file (in bytes) */
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uint16_t type; /* one of SYS_TYPE_* above */
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uint16_t nlinks; /* # of hard links to this file */
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uint32_t blocks; /* # of blocks */
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uint32_t direct[SFS_NDIRECT]; /* direct blocks */
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uint32_t indirect; /* indirect blocks */
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// uint32_t db_indirect; /* double indirect blocks */
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// unused
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};
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/* file entry (on disk) */
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struct sfs_disk_entry {
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uint32_t ino; /* inode number */
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char name[SFS_MAX_FNAME_LEN + 1]; /* file name */
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};
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#define sfs_dentry_size \
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sizeof(((struct sfs_disk_entry *)0)->name)
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/* inode for sfs */
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struct sfs_inode {
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struct sfs_disk_inode *din; /* on-disk inode */
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uint32_t ino; /* inode number */
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bool dirty; /* true if inode modified */
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int reclaim_count; /* kill inode if it hits zero */
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semaphore_t sem; /* semaphore for din */
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list_entry_t inode_link; /* entry for linked-list in sfs_fs */
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list_entry_t hash_link; /* entry for hash linked-list in sfs_fs */
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};
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#define le2sin(le, member) \
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to_struct((le), struct sfs_inode, member)
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/* filesystem for sfs */
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struct sfs_fs {
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struct sfs_super super; /* on-disk superblock */
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struct device *dev; /* device mounted on */
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struct bitmap *freemap; /* blocks in use are mared 0 */
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bool super_dirty; /* true if super/freemap modified */
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void *sfs_buffer; /* buffer for non-block aligned io */
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semaphore_t fs_sem; /* semaphore for fs */
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semaphore_t io_sem; /* semaphore for io */
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semaphore_t mutex_sem; /* semaphore for link/unlink and rename */
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list_entry_t inode_list; /* inode linked-list */
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list_entry_t *hash_list; /* inode hash linked-list */
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};
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/* hash for sfs */
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#define SFS_HLIST_SHIFT 10
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#define SFS_HLIST_SIZE (1 << SFS_HLIST_SHIFT)
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#define sin_hashfn(x) (hash32(x, SFS_HLIST_SHIFT))
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/* size of freemap (in bits) */
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#define sfs_freemap_bits(super) ROUNDUP((super)->blocks, SFS_BLKBITS)
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/* size of freemap (in blocks) */
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#define sfs_freemap_blocks(super) ROUNDUP_DIV((super)->blocks, SFS_BLKBITS)
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struct fs;
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struct inode;
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void sfs_init(void);
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int sfs_mount(const char *devname);
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void lock_sfs_fs(struct sfs_fs *sfs);
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void lock_sfs_io(struct sfs_fs *sfs);
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void unlock_sfs_fs(struct sfs_fs *sfs);
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void unlock_sfs_io(struct sfs_fs *sfs);
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int sfs_rblock(struct sfs_fs *sfs, void *buf, uint32_t blkno, uint32_t nblks);
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int sfs_wblock(struct sfs_fs *sfs, void *buf, uint32_t blkno, uint32_t nblks);
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int sfs_rbuf(struct sfs_fs *sfs, void *buf, size_t len, uint32_t blkno, off_t offset);
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int sfs_wbuf(struct sfs_fs *sfs, void *buf, size_t len, uint32_t blkno, off_t offset);
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int sfs_sync_super(struct sfs_fs *sfs);
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int sfs_sync_freemap(struct sfs_fs *sfs);
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int sfs_clear_block(struct sfs_fs *sfs, uint32_t blkno, uint32_t nblks);
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int sfs_load_inode(struct sfs_fs *sfs, struct inode **node_store, uint32_t ino);
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#endif /* !__KERN_FS_SFS_SFS_H__ */
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