xv6-riscv-kernel/kernel/buf.h

struct buf {
  int valid;   // has data been read from disk?
  int disk;    // does disk "own" buf?
  uint dev;
  uint blockno;
  struct sleeplock lock;
  uint refcnt;
  struct buf *prev; // LRU cache list
  struct buf *next;
  uchar data[BSIZE];
};
bread iget mkfs makes a file system image put this in your .bochsrc: ata0-slave: type=disk, mode=flat, path="fs.img", cylinders=1024, heads=1, spt=1 2006-07-21 15:18:04 +02:00			`struct buf {`
Remove B_DIRTY Use refcnt to pin blocks into the cache Replace flags/B_VALID with a boolean field valid Use info[id].status to signal completion of disk interrupt Pass a read/write flag to virtio_disk_rw 2019-07-29 23:33:16 +02:00			`int valid; // has data been read from disk?`
Track in buf if disk "owns" buffer 2019-07-30 18:53:19 +02:00			`int disk; // does disk "own" buf?`
fix getblk to actually lock the block no more cons_put system calls usertests tests two processes writing files 2006-08-12 13:38:57 +02:00			`uint dev;`
Disentangle block size from the disk's sector size. Set block size to 1024 to show that they can be different. Clean up mkfs, simplifying specifying fs parameters, remove some redundancy between fs and mkfs, and fix disk layout bugs. Call blocks in the file system blocks instead of sectors. Passes usertests for different block sizes. 2015-04-03 14:22:02 +02:00			`uint blockno;`
Straight replacement of B_BUSY with a sleeping lock. 2016-09-11 23:24:04 +02:00			`struct sleeplock lock;`
Move retry loop/sleep/wakeup in bio.c into sleeping locks 2016-09-12 02:17:22 +02:00			`uint refcnt;`
simplify ide queuing nits in comments 2007-08-24 21:32:36 +02:00			`struct buf *prev; // LRU cache list`
LRU disk cache replacement 2006-08-13 00:34:13 +02:00			`struct buf *next;`
Disentangle block size from the disk's sector size. Set block size to 1024 to show that they can be different. Clean up mkfs, simplifying specifying fs parameters, remove some redundancy between fs and mkfs, and fix disk layout bugs. Call blocks in the file system blocks instead of sectors. Passes usertests for different block sizes. 2015-04-03 14:22:02 +02:00			`uchar data[BSIZE];`
bread iget mkfs makes a file system image put this in your .bochsrc: ata0-slave: type=disk, mode=flat, path="fs.img", cylinders=1024, heads=1, spt=1 2006-07-21 15:18:04 +02:00			`};`
Another attempt at the bio.c comment. Rename B_WRITE to B_DIRTY and then let ide.c maintain the B_VALID and B_DIRTY flags. 2007-08-27 16:09:30 +02:00