minix/minix/fs/ext2/buf.h

#ifndef EXT2_BUF_H
#define EXT2_BUF_H

union fsdata_u {
    char b__data[1];		/* ordinary user data */
    block_t b__ind[1];		/* indirect block */
    bitchunk_t b__bitmap[1];	/* bit map block */
};

/* These defs make it possible to use to bp->b_data instead of bp->b.b__data */
#define b_data(bp)   ((union fsdata_u *) bp->data)->b__data
#define b_ind(bp) ((union fsdata_u *) bp->data)->b__ind
#define b_bitmap(bp) ((union fsdata_u *) bp->data)->b__bitmap

#endif /* EXT2_BUF_H */
Add support for the ext2 file system. Contributed by Evgeniy Ivanov. 2010-08-02 13:44:45 +02:00			`#ifndef EXT2_BUF_H`
			`#define EXT2_BUF_H`

			`union fsdata_u {`
libminixfs: miscellaneous API cleanup Mostly removal of unused parameters from calls. Change-Id: I0eb7b568265d1669492d958e78b9e69d7cf6fc05 2015-03-28 01:45:28 +01:00			`char b__data[1]; /* ordinary user data */`
			`block_t b__ind[1]; /* indirect block */`
			`bitchunk_t b__bitmap[1]; /* bit map block */`
Add support for the ext2 file system. Contributed by Evgeniy Ivanov. 2010-08-02 13:44:45 +02:00			`};`

			`/* These defs make it possible to use to bp->b_data instead of bp->b.b__data */`
Move primary cache code to libminixfs. Add primary cache management feature to libminixfs as mfs and ext2 currently do separately, remove cache code from mfs and ext2, and make them use the libminixfs interface. This makes all fields of the buf struct private to libminixfs and FS clients aren't supposed to access them at all. Only the opaque 'void *data' field (the FS block contents, used to be called bp) is to be accessed by the FS client. The main purpose is to implement the interface to the 2ndary vm cache just once, get rid of some code duplication, and add a little abstraction to reduce the code inertia of the whole caching business. Some minor sanity checking and prohibition done by mfs in this code as removed from the generic primary cache code as a result: - checking all inodes are not in use when allocating/resizing the cache - checking readonly filesystems aren't written to - checking the superblock isn't written to on mounted filesystems The minixfslib code relies on fs_blockstats() in the client filesystem to return some FS usage information. 2012-10-16 17:40:39 +02:00			`#define b_data(bp) ((union fsdata_u *) bp->data)->b__data`
			`#define b_ind(bp) ((union fsdata_u *) bp->data)->b__ind`
			`#define b_bitmap(bp) ((union fsdata_u *) bp->data)->b__bitmap`
Add support for the ext2 file system. Contributed by Evgeniy Ivanov. 2010-08-02 13:44:45 +02:00
			`#endif /* EXT2_BUF_H */`