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drasko |
/*
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* The disk layout of our simple unix-like filesystem.
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*
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* Copyright (C) 2007, 2008 Bahadir Balban
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*/
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#ifndef __MEMFS_LAYOUT_H__
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#define __MEMFS_LAYOUT_H__
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#include <l4lib/types.h>
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#include <l4/lib/list.h>
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#include <l4/macros.h>
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#include <l4/config.h>
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#include INC_GLUE(memory.h)
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#include <memcache/memcache.h>
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#include <lib/idpool.h>
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/*
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*
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* Filesystem layout:
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*
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* |---------------|
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* | Superblock |
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* |---------------|
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*
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* Superblock layout:
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*
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* |---------------|
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* | inode cache |
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* |---------------|
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* | dentry cache |
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* |---------------|
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* | block cache |
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* |---------------|
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*
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*/
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/*
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* These fixed filesystem limits make it much easier to implement
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* filesystem space allocation.
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*/
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#define MEMFS_TOTAL_SIZE SZ_4MB
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#define MEMFS_TOTAL_INODES 128
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#define MEMFS_TOTAL_BLOCKS 2000
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#define MEMFS_FMAX_BLOCKS 120
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#define MEMFS_BLOCK_SIZE PAGE_SIZE
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#define MEMFS_MAGIC 0xB
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#define MEMFS_NAME "memfs"
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#define MEMFS_NAME_SIZE 8
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struct memfs_inode {
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u32 inum; /* Inode number */
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u32 mode; /* File permissions */
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u32 owner; /* File owner */
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u64 atime; /* Last access time */
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u64 mtime; /* Last content modification */
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u64 ctime; /* Last inode modification */
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u64 size; /* Size of contents */
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void *block[MEMFS_FMAX_BLOCKS]; /* Number of blocks */
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};
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struct memfs_superblock {
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u32 magic; /* Filesystem magic number */
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char name[8];
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int fsidx; /* Index that gets orred to get global vnum */
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u32 blocksize; /* Filesystem block size */
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u64 fmaxblocks; /* Maximum number of blocks per file */
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u64 fssize; /* Total size of filesystem */
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unsigned long root_vnum; /* The root vnum of this superblock */
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struct link inode_cache_list; /* Chain of alloc caches */
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struct link block_cache_list; /* Chain of alloc caches */
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struct id_pool *ipool; /* Index pool for inodes */
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struct id_pool *bpool; /* Index pool for blocks */
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struct memfs_inode *inode[MEMFS_TOTAL_INODES]; /* Table of inodes */
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void *block[MEMFS_TOTAL_BLOCKS]; /* Table of fs blocks */
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} __attribute__ ((__packed__));
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#define MEMFS_DNAME_MAX 32
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struct memfs_dentry {
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u32 inum; /* Inode number */
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u32 offset; /* Dentry offset in its buffer */
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u16 rlength; /* Record length */
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u8 type; /* Record type */
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u8 name[MEMFS_DNAME_MAX]; /* Name string */
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} __attribute__((__packed__));
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extern struct vnode_ops memfs_vnode_operations;
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extern struct superblock_ops memfs_superblock_operations;
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extern struct file_ops memfs_file_operations;
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int memfs_format_filesystem(void *buffer);
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struct memfs_inode *memfs_create_inode(struct memfs_superblock *sb);
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void memfs_register_fstype(struct link *);
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struct superblock *memfs_get_superblock(void *block);
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int memfs_generate_superblock(void *block);
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void *memfs_alloc_block(struct memfs_superblock *sb);
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int memfs_free_block(struct memfs_superblock *sb, void *block);
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#endif /* __MEMFS_LAYOUT_H__ */
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