sanchayanmaity/minix
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
minix/servers/ext2/buf.h

35 lines
1.3 KiB
C
Raw Normal View History

Add support for the ext2 file system. Contributed by Evgeniy Ivanov.
2010-08-02 13:44:45 +02:00
/* Buffer (block) cache. To acquire a block, a routine calls get_block(),
* telling which block it wants. The block is then regarded as "in use"
* and has its 'b_count' field incremented. All the blocks that are not
* in use are chained together in an LRU list, with 'front' pointing
* to the least recently used block, and 'rear' to the most recently used
* block. A reverse chain, using the field b_prev is also maintained.
* Usage for LRU is measured by the time the put_block() is done. The second
* parameter to put_block() can violate the LRU order and put a block on the
* front of the list, if it will probably not be needed soon. If a block
* is modified, the modifying routine must set b_dirt to DIRTY, so the block
* will eventually be rewritten to the disk.
*/
#ifndef EXT2_BUF_H
#define EXT2_BUF_H
netbsd dirent.h, import sys/sys *.h, mfs cleanup . add all sys/sys headers not already present to help compiling . take netbsd dirent.h and struct dirent; main result is introducing d_type and d_namlen that have to be set by getdents() in all FS code implementing it . d_off is gone . alignment of the struct has become 8 bytes instead of 4 . remove _MAX_BLOCK_SIZE, _MIN_BLOCK_SIZE, _STATIC_BLOCK_SIZE . libminlib: cleanup unused yet duplicate code . mfs: throw out the long-broken v1, v2 support . new test for dirent contents filled by getdents() Change-Id: I1459755c7ba5e5d1c9396d3a587ce6e63ddc283e
2013-09-16 22:52:36 +02:00
#include <sys/dirent.h>
Add support for the ext2 file system. Contributed by Evgeniy Ivanov.
2010-08-02 13:44:45 +02:00
union fsdata_u {
netbsd dirent.h, import sys/sys *.h, mfs cleanup . add all sys/sys headers not already present to help compiling . take netbsd dirent.h and struct dirent; main result is introducing d_type and d_namlen that have to be set by getdents() in all FS code implementing it . d_off is gone . alignment of the struct has become 8 bytes instead of 4 . remove _MAX_BLOCK_SIZE, _MIN_BLOCK_SIZE, _STATIC_BLOCK_SIZE . libminlib: cleanup unused yet duplicate code . mfs: throw out the long-broken v1, v2 support . new test for dirent contents filled by getdents() Change-Id: I1459755c7ba5e5d1c9396d3a587ce6e63ddc283e
2013-09-16 22:52:36 +02:00
char b__data[1]; /* ordinary user data */
Add support for the ext2 file system. Contributed by Evgeniy Ivanov.
2010-08-02 13:44:45 +02:00
/* indirect block */
netbsd dirent.h, import sys/sys *.h, mfs cleanup . add all sys/sys headers not already present to help compiling . take netbsd dirent.h and struct dirent; main result is introducing d_type and d_namlen that have to be set by getdents() in all FS code implementing it . d_off is gone . alignment of the struct has become 8 bytes instead of 4 . remove _MAX_BLOCK_SIZE, _MIN_BLOCK_SIZE, _STATIC_BLOCK_SIZE . libminlib: cleanup unused yet duplicate code . mfs: throw out the long-broken v1, v2 support . new test for dirent contents filled by getdents() Change-Id: I1459755c7ba5e5d1c9396d3a587ce6e63ddc283e
2013-09-16 22:52:36 +02:00
block_t b__ind[1];
Add support for the ext2 file system. Contributed by Evgeniy Ivanov.
2010-08-02 13:44:45 +02:00
/* bit map block */
netbsd dirent.h, import sys/sys *.h, mfs cleanup . add all sys/sys headers not already present to help compiling . take netbsd dirent.h and struct dirent; main result is introducing d_type and d_namlen that have to be set by getdents() in all FS code implementing it . d_off is gone . alignment of the struct has become 8 bytes instead of 4 . remove _MAX_BLOCK_SIZE, _MIN_BLOCK_SIZE, _STATIC_BLOCK_SIZE . libminlib: cleanup unused yet duplicate code . mfs: throw out the long-broken v1, v2 support . new test for dirent contents filled by getdents() Change-Id: I1459755c7ba5e5d1c9396d3a587ce6e63ddc283e
2013-09-16 22:52:36 +02:00
bitchunk_t b__bitmap[1];
Add support for the ext2 file system. Contributed by Evgeniy Ivanov.
2010-08-02 13:44:45 +02:00
};
/* A block is free if b_dev == NO_DEV. */
/* 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 */
Reference in a new issue Copy permalink