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#ifndef __MFS_SUPER_H__
#define __MFS_SUPER_H__
/* Super block table. The root file system and every mounted file system
* has an entry here. The entry holds information about the sizes of the bit
* maps and inodes. The s_ninodes field gives the number of inodes available
* for files and directories, including the root directory. Inode 0 is
* on the disk, but not used. Thus s_ninodes = 4 means that 5 bits will be
* used in the bit map, bit 0, which is always 1 and not used, and bits 1-4
* for files and directories. The disk layout is:
*
* Item # blocks
* boot block 1
* super block 1 (offset 1kB)
* inode map s_imap_blocks
* zone map s_zmap_blocks
* inodes (s_ninodes + 'inodes per block' - 1)/'inodes per block'
* unused whatever is needed to fill out the current zone
* data zones (s_zones - s_firstdatazone) << s_log_zone_size
*
* A super_block slot is free if s_dev == NO_DEV.
*/
EXTERN struct super_block {
u32_t s_ninodes; /* # usable inodes on the minor device */
zone1_t s_nzones; /* total device size, including bit maps etc */
short s_imap_blocks; /* # of blocks used by inode bit map */
short s_zmap_blocks; /* # of blocks used by zone bit map */
zone1_t s_firstdatazone_old; /* number of first data zone (small) */
short s_log_zone_size; /* log2 of blocks/zone */
unsigned short s_flags; /* FS state flags */
i32_t s_max_size; /* maximum file size on this device */
zone_t s_zones; /* number of zones (replaces s_nzones in V2) */
short s_magic; /* magic number to recognize super-blocks */
/* The following items are valid on disk only for V3 and above */
short s_pad2; /* try to avoid compiler-dependent padding */
unsigned short s_block_size; /* block size in bytes. */
char s_disk_version; /* filesystem format sub-version */
/* The following items are only used when the super_block is in memory.
* If this ever changes, i.e. more fields after s_disk_version has to go to
* disk, update LAST_ONDISK_FIELD in super.c as that controls which part of the
* struct is copied to and from disk.
*/
/*struct inode *s_isup;*/ /* inode for root dir of mounted file sys */
/*struct inode *s_imount;*/ /* inode mounted on */
unsigned s_inodes_per_block; /* precalculated from magic number */
zone_t s_firstdatazone; /* number of first data zone (big) */
dev_t s_dev; /* whose super block is this? */
int s_rd_only; /* set to 1 iff file sys mounted read only */
int s_native; /* set to 1 iff not byte swapped file system */
int s_version; /* file system version, zero means bad magic */
int s_ndzones; /* # direct zones in an inode */
int s_nindirs; /* # indirect zones per indirect block */
bit_t s_isearch; /* inodes below this bit number are in use */
bit_t s_zsearch; /* all zones below this bit number are in use*/
} superblock;
#define IMAP 0 /* operating on the inode bit map */
#define ZMAP 1 /* operating on the zone bit map */
/* s_flags contents; undefined flags are guaranteed to be zero on disk
* (not counting future versions of mfs setting them!)
*/
#define MFSFLAG_CLEAN (1L << 0) /* 0: dirty; 1: FS was unmounted cleanly */
/* Future compatability (or at least, graceful failure):
* if any of these bits are on, and the MFS or fsck
* implementation doesn't understand them, do not mount/fsck
* the FS.
*/
#define MFSFLAG_MANDATORY_MASK 0xff00
#endif
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