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

1 files changed, 73 insertions, 0 deletions

diff --git a/fs.c b/fs.c
new file mode 100644
index 0000000..48c943a
--- /dev/null
+++ b/fs.c
@@ -0,0 +1,73 @@
+#include "types.h"
+#include "param.h"
+#include "x86.h"
+#include "mmu.h"
+#include "proc.h"
+#include "defs.h"
+#include "spinlock.h"
+#include "buf.h"
+#include "fs.h"
+#include "fsvar.h"
+
+// these are inodes currently in use
+// an entry is free if count == 0
+struct inode inode[NINODE];
+struct spinlock inode_table_lock;
+
+struct inode *
+iget(uint dev, uint inum)
+{
+  struct inode *ip, *nip = 0;
+  struct dinode *dip;
+  struct buf *bp;
+
+  acquire(&inode_table_lock);
+
+ loop:
+  for(ip = &inode[0]; ip < &inode[NINODE]; ip++){
+    if(ip->count > 0 && ip->dev == dev && ip->inum == inum){
+      if(ip->busy){
+        sleep(ip, &inode_table_lock);
+        goto loop;
+      }
+      ip->count++;
+      release(&inode_table_lock);
+      return ip;
+    }
+    if(nip == 0 && ip->count == 0)
+      nip = ip;
+  }
+
+  if(nip == 0)
+    panic("out of inodes");
+
+  nip->dev = dev;
+  nip->inum = inum;
+  nip->count = 1;
+  nip->busy = 1;
+
+  release(&inode_table_lock);
+
+  bp = bread(dev, inum / IPB + 2);
+  dip = &((struct dinode *)(bp->data))[inum % IPB];
+  nip->type = dip->type;
+  nip->nlink = dip->nlink;
+  nip->size = dip->size;
+  memmove(nip->addrs, dip->addrs, sizeof(nip->addrs));
+  cprintf("bn %d off %d\n", inum / IPB + 2, (unsigned)dip - (unsigned)bp->data);
+  brelse(bp);
+
+  return nip;
+}
+
+void
+iput(struct inode *ip)
+{
+  acquire(&inode_table_lock);
+
+  ip->count -= 1;
+  ip->busy = 0;
+  wakeup(ip);
+
+  release(&inode_table_lock);
+}