xv6/buf.h

struct buf {
  int flags;
  uint dev;
  uint sector;
  struct buf *prev; // LRU cache list
  struct buf *next;
  struct buf *qnext; // disk queue
  uchar data[512];
};
#define B_BUSY  0x1  // buffer is locked by some process
#define B_VALID 0x2  // buffer has been read from disk
#define B_DIRTY 0x4  // buffer needs to be written to disk
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 13:18:04 +00:00			`struct buf {`
			`int flags;`
fix getblk to actually lock the block no more cons_put system calls usertests tests two processes writing files 2006-08-12 11:38:57 +00:00			`uint dev;`
			`uint sector;`
simplify ide queuing nits in comments 2007-08-24 19:32:36 +00:00			`struct buf *prev; // LRU cache list`
LRU disk cache replacement 2006-08-12 22:34:13 +00:00			`struct buf *next;`
simplify ide queuing nits in comments 2007-08-24 19:32:36 +00:00			`struct buf *qnext; // disk queue`
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 13:18:04 +00:00			`uchar data[512];`
			`};`
Revert "Introduce and use sleeplocks instead of BUSY flags" My changes have a race with re-used bufs and the code doesn't seem to get shorter Keep the changes that fixed ip->off race This reverts commit 3a5fa7ed9020eaf8ab843a16d26db7393b2ec072. Conflicts: defs.h file.c file.h 2011-08-29 21:18:40 +00:00			`#define B_BUSY 0x1 // buffer is locked by some process`
			`#define B_VALID 0x2 // buffer has been read from disk`
			`#define B_DIRTY 0x4 // buffer needs to be written to disk`
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 14:09:30 +00:00