kern

annotate src/fs.h @ 94:b3351d018ac6

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read/write superblock, get/put inode
author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 11 Dec 2011 11:12:30 +0200
parents 083849df660b
children ec62cbe00b55
rev   line source
nuclear@88 1 #ifndef FS_H_
nuclear@88 2 #define FS_H_
nuclear@88 3
nuclear@90 4 #include <inttypes.h>
nuclear@90 5
nuclear@90 6 #define MAGIC 0xccf5ccf5
nuclear@93 7 #define FS_VER 1
nuclear@90 8 #define BLKSZ 1024
nuclear@90 9
nuclear@90 10 #define SECT_TO_BLK(x) ((x) / (BLKSZ / 512))
nuclear@90 11
nuclear@91 12 #define DEVNO(maj, min) ((((maj) & 0xff) << 8) | ((min) & 0xff))
nuclear@90 13 #define DEV_MAJOR(dev) (((dev) >> 8) & 0xff)
nuclear@90 14 #define DEV_MINOR(dev) ((dev) & 0xff)
nuclear@90 15
nuclear@90 16
nuclear@90 17 typedef uint32_t dev_t;
nuclear@90 18 typedef uint32_t blkid;
nuclear@90 19
nuclear@94 20
nuclear@94 21 /* 20 direct blocks + 10 attributes + 2 indirect = 128 bytes per inode */
nuclear@94 22 #define NDIRBLK 20
nuclear@94 23 struct inode {
nuclear@94 24 int ino;
nuclear@94 25 int uid, gid, mode;
nuclear@94 26 int nlink;
nuclear@94 27 dev_t dev;
nuclear@94 28 uint32_t atime, ctime, mtime;
nuclear@94 29 uint32_t size;
nuclear@94 30 blkid blk[NDIRBLK]; /* direct blocks */
nuclear@94 31 blkid ind; /* indirect */
nuclear@94 32 blkid dind; /* double-indirect */
nuclear@94 33 } __attribute__((packed));
nuclear@94 34
nuclear@94 35
nuclear@90 36 struct superblock {
nuclear@90 37 uint32_t magic; /* magic number */
nuclear@90 38 int ver; /* filesystem version */
nuclear@90 39 int blksize; /* only BLKSZ supported at the moment */
nuclear@90 40
nuclear@90 41 /* total number of blocks */
nuclear@90 42 unsigned int num_blocks;
nuclear@90 43 /* inode allocation bitmap start and count */
nuclear@90 44 blkid ibm_start;
nuclear@90 45 unsigned int ibm_count;
nuclear@90 46 /* inode table start and count */
nuclear@90 47 blkid itbl_start;
nuclear@90 48 unsigned int itbl_count;
nuclear@93 49 /* block allocation bitmap start and count */
nuclear@93 50 blkid bm_start;
nuclear@93 51 unsigned int bm_count;
nuclear@90 52
nuclear@94 53 int root_ino; /* root direcotry inode number */
nuclear@90 54
nuclear@90 55 /* the following are valid only at runtime, ignored on disk */
nuclear@93 56 uint32_t *ibm; /* in-memory inode bitmap */
nuclear@93 57 uint32_t *bm; /* in-memory block bitmap */
nuclear@94 58 struct inode *root; /* in-memory root inode */
nuclear@90 59
nuclear@90 60 } __attribute__((packed));
nuclear@90 61
nuclear@90 62
nuclear@90 63
nuclear@93 64 struct filesys {
nuclear@93 65 struct block_device *bdev;
nuclear@93 66
nuclear@93 67 struct superblock *sb;
nuclear@93 68
nuclear@93 69 struct filesys *next;
nuclear@93 70 };
nuclear@93 71
nuclear@93 72 /* defined in fs.c */
nuclear@93 73 int openfs(struct filesys *fs, dev_t dev);
nuclear@94 74 void closefs(struct filesys *fs);
nuclear@93 75 int find_inode(const char *path);
nuclear@93 76
nuclear@93 77 /* defined in fs_sys.c */
nuclear@90 78 int sys_mount(char *mntpt, char *devname, unsigned int flags);
nuclear@90 79 int sys_umount(char *devname);
nuclear@90 80
nuclear@90 81 int sys_open(char *pathname, int flags, unsigned int mode);
nuclear@90 82 int sys_close(int fd);
nuclear@90 83
nuclear@90 84 int sys_read(int fd, void *buf, int sz);
nuclear@90 85 int sys_write(int fd, void *buf, int sz);
nuclear@90 86 long sys_lseek(int fd, long offs, int from);
nuclear@90 87
nuclear@89 88
nuclear@88 89 #endif /* FS_H_ */