1.1 --- a/include/kdef.h	Sun Dec 11 10:17:58 2011 +0200
     1.2 +++ b/include/kdef.h	Sun Dec 11 11:12:30 2011 +0200
     1.3 @@ -29,14 +29,17 @@
     1.4  
     1.5  /* --- defines for errno.h */
     1.6  #if defined(KERNEL) || defined(KDEF_ERRNO_H)
     1.7 -#define EAGAIN		1
     1.8 -#define EINVAL		2
     1.9 -#define ECHILD		3
    1.10 -#define EBUSY		4
    1.11 -#define ENOMEM		5
    1.12 -#define EIO			6
    1.13 +#define EFOO		1 /* I just like to return -1 some times :) */
    1.14  
    1.15 -#define EBUG		127	/* error: feature not implemented yet */
    1.16 +#define EAGAIN		2
    1.17 +#define EINVAL		3
    1.18 +#define ECHILD		4
    1.19 +#define EBUSY		5
    1.20 +#define ENOMEM		6
    1.21 +#define EIO			7
    1.22 +#define ENOENT		8
    1.23 +
    1.24 +#define EBUG		127	/* for missing features and known bugs */
    1.25  #endif	/* errno.h */
    1.26  
    1.27  

     2.1 --- a/src/fs.c	Sun Dec 11 10:17:58 2011 +0200
     2.2 +++ b/src/fs.c	Sun Dec 11 11:12:30 2011 +0200
     2.3 @@ -4,47 +4,52 @@
     2.4   */
     2.5  #include <stdio.h>
     2.6  #include <stdlib.h>
     2.7 +#include <string.h>
     2.8  #include <errno.h>
     2.9 +#include <assert.h>
    2.10  #include "fs.h"
    2.11  #include "bdev.h"
    2.12  
    2.13  
    2.14  int openfs(struct filesys *fs, dev_t dev);
    2.15 -static int read_superblock(struct block_device *bdev, struct superblock *sb);
    2.16 -
    2.17 +static int read_superblock(struct filesys *fs);
    2.18 +static int write_superblock(struct filesys *fs);
    2.19 +static int get_inode(struct filesys *fs, int ino, struct inode *inode);
    2.20 +static int put_inode(struct filesys *fs, struct inode *inode);
    2.21  
    2.22  int openfs(struct filesys *fs, dev_t dev)
    2.23  {
    2.24  	int res;
    2.25  	struct block_device *bdev;
    2.26 -	struct superblock *sb = 0;
    2.27 +
    2.28 +	assert(BLKSZ % sizeof(struct inode) == 0);
    2.29  
    2.30  	if(!(bdev = blk_open(dev))) {
    2.31  		return -ENOENT;
    2.32  	}
    2.33 +	fs->bdev = bdev;
    2.34  
    2.35  	/* read the superblock */
    2.36 -	if(!(sb = malloc(BLKSZ))) {
    2.37 +	if(!(fs->sb = malloc(BLKSZ))) {
    2.38  		res = -ENOMEM;
    2.39  		goto done;
    2.40  	}
    2.41 -	if((res = read_superblock(bdev, sb)) != 0) {
    2.42 +	if((res = read_superblock(fs)) != 0) {
    2.43  		goto done;
    2.44  	}
    2.45  
    2.46  
    2.47 -
    2.48 -
    2.49  done:
    2.50  	blk_close(bdev);
    2.51 -	free(sb);
    2.52  	return res;
    2.53  }
    2.54  
    2.55 -static int read_superblock(struct block_device *bdev, struct superblock *sb)
    2.56 +static int read_superblock(struct filesys *fs)
    2.57  {
    2.58 +	struct superblock *sb = fs->sb;
    2.59 +
    2.60  	/* read superblock and verify */
    2.61 -	if(blk_read(bdev, 1, 1, sb) == -1) {
    2.62 +	if(blk_read(fs->bdev, 1, 1, sb) == -1) {
    2.63  		printf("failed to read superblock\n");
    2.64  		return -EIO;
    2.65  	}
    2.66 @@ -65,7 +70,7 @@
    2.67  	if(!(sb->ibm = malloc(sb->ibm_count * sb->blksize))) {
    2.68  		return -ENOMEM;
    2.69  	}
    2.70 -	if(blk_read(bdev, sb->ibm_start, sb->ibm_count, sb->ibm) == -1) {
    2.71 +	if(blk_read(fs->bdev, sb->ibm_start, sb->ibm_count, sb->ibm) == -1) {
    2.72  		printf("failed to read inode bitmap\n");
    2.73  		free(sb->ibm);
    2.74  		return -EIO;
    2.75 @@ -74,12 +79,80 @@
    2.76  		free(sb->ibm);
    2.77  		return -ENOMEM;
    2.78  	}
    2.79 -	if(blk_read(bdev, sb->bm_start, sb->bm_count, sb->bm) == -1) {
    2.80 +	if(blk_read(fs->bdev, sb->bm_start, sb->bm_count, sb->bm) == -1) {
    2.81  		printf("failed to read block bitmap\n");
    2.82  		free(sb->ibm);
    2.83  		free(sb->bm);
    2.84  		return -EIO;
    2.85  	}
    2.86  
    2.87 +	/* read the root inode */
    2.88 +	if(!(sb->root = malloc(sizeof *sb->root))) {
    2.89 +		free(sb->ibm);
    2.90 +		free(sb->bm);
    2.91 +		return -ENOMEM;
    2.92 +	}
    2.93 +	if(get_inode(fs, sb->root_ino, sb->root) == -1) {
    2.94 +		printf("failed to read root inode\n");
    2.95 +		return -1;
    2.96 +	}
    2.97 +
    2.98  	return 0;
    2.99  }
   2.100 +
   2.101 +static int write_superblock(struct filesys *fs)
   2.102 +{
   2.103 +	struct superblock *sb = fs->sb;
   2.104 +
   2.105 +	/* write back any changes in the root inode */
   2.106 +	if(put_inode(fs, sb->root) == -1) {
   2.107 +		return -1;
   2.108 +	}
   2.109 +	/* write back the block bitmap */
   2.110 +	if(blk_write(fs->bdev, sb->bm_start, sb->bm_count, sb->bm) == -1) {
   2.111 +		return -1;
   2.112 +	}
   2.113 +	/* write back the inode bitmap */
   2.114 +	if(blk_write(fs->bdev, sb->ibm_start, sb->ibm_count, sb->ibm) == -1) {
   2.115 +		return -1;
   2.116 +	}
   2.117 +	return 0;
   2.118 +}
   2.119 +
   2.120 +/* number of inodes in a block */
   2.121 +#define BLK_INODES		(BLKSZ / sizeof(struct inode))
   2.122 +
   2.123 +/* copy the requested inode from the disk, into the buffer passed in the last arg */
   2.124 +static int get_inode(struct filesys *fs, int ino, struct inode *inode)
   2.125 +{
   2.126 +	struct inode *buf = malloc(BLKSZ);
   2.127 +	assert(buf);
   2.128 +
   2.129 +	if(blk_read(fs->bdev, fs->sb->itbl_start + ino / BLK_INODES, 1, buf) == -1) {
   2.130 +		free(buf);
   2.131 +		return -1;
   2.132 +	}
   2.133 +	memcpy(inode, buf + ino % BLK_INODES, sizeof *inode);
   2.134 +	free(buf);
   2.135 +	return 0;
   2.136 +}
   2.137 +
   2.138 +/* write the inode to the disk */
   2.139 +static int put_inode(struct filesys *fs, struct inode *inode)
   2.140 +{
   2.141 +	struct inode *buf = malloc(BLKSZ);
   2.142 +	assert(buf);
   2.143 +
   2.144 +	if(blk_read(fs->bdev, fs->sb->itbl_start + inode->ino / BLK_INODES, 1, buf) == -1) {
   2.145 +		free(buf);
   2.146 +		return -1;
   2.147 +	}
   2.148 +	memcpy(buf + inode->ino % BLK_INODES, inode, sizeof *inode);
   2.149 +
   2.150 +	if(blk_write(fs->bdev, fs->sb->itbl_start + inode->ino / BLK_INODES, 1, buf) == -1) {
   2.151 +		free(buf);
   2.152 +		return -1;
   2.153 +	}
   2.154 +	free(buf);
   2.155 +	return 0;
   2.156 +}

     3.1 --- a/src/fs.h	Sun Dec 11 10:17:58 2011 +0200
     3.2 +++ b/src/fs.h	Sun Dec 11 11:12:30 2011 +0200
     3.3 @@ -17,6 +17,22 @@
     3.4  typedef uint32_t dev_t;
     3.5  typedef uint32_t blkid;
     3.6  
     3.7 +
     3.8 +/* 20 direct blocks + 10 attributes + 2 indirect = 128 bytes per inode */
     3.9 +#define NDIRBLK	20
    3.10 +struct inode {
    3.11 +	int ino;
    3.12 +	int uid, gid, mode;
    3.13 +	int nlink;
    3.14 +	dev_t dev;
    3.15 +	uint32_t atime, ctime, mtime;
    3.16 +	uint32_t size;
    3.17 +	blkid blk[NDIRBLK];	/* direct blocks */
    3.18 +	blkid ind;			/* indirect */
    3.19 +	blkid dind;			/* double-indirect */
    3.20 +} __attribute__((packed));
    3.21 +
    3.22 +
    3.23  struct superblock {
    3.24  	uint32_t magic;	/* magic number */
    3.25  	int ver;		/* filesystem version */
    3.26 @@ -34,33 +50,19 @@
    3.27  	blkid bm_start;
    3.28  	unsigned int bm_count;
    3.29  
    3.30 -	int root_ino;	/* root direcotry inode */
    3.31 +	int root_ino;	/* root direcotry inode number */
    3.32  
    3.33  	/* the following are valid only at runtime, ignored on disk */
    3.34  	uint32_t *ibm;	/* in-memory inode bitmap */
    3.35  	uint32_t *bm;	/* in-memory block bitmap */
    3.36 +	struct inode *root;	/* in-memory root inode */
    3.37  
    3.38  } __attribute__((packed));
    3.39  
    3.40  
    3.41 -/* 20 direct blocks + 10 attributes + 2 indirect = 128 bytes per inode */
    3.42 -#define NDIRBLK	20
    3.43 -struct inode {
    3.44 -	int ino;
    3.45 -	int uid, gid, mode;
    3.46 -	int nlink;
    3.47 -	dev_t dev;
    3.48 -	uint32_t atime, ctime, mtime;
    3.49 -	uint32_t size;
    3.50 -	blkid blk[NDIRBLK];	/* direct blocks */
    3.51 -	blkid ind;			/* indirect */
    3.52 -	blkid dind;			/* double-indirect */
    3.53 -} __attribute__((packed));
    3.54 -
    3.55  
    3.56  struct filesys {
    3.57  	struct block_device *bdev;
    3.58 -	struct partition part;
    3.59  
    3.60  	struct superblock *sb;
    3.61  
    3.62 @@ -69,6 +71,7 @@
    3.63  
    3.64  /* defined in fs.c */
    3.65  int openfs(struct filesys *fs, dev_t dev);
    3.66 +void closefs(struct filesys *fs);
    3.67  int find_inode(const char *path);
    3.68  
    3.69  /* defined in fs_sys.c */