uint inum; // Inode number
int ref; // Reference count
struct sleeplock lock;
- int flags; // I_VALID
+ int valid; // remainder has been read from disk?
short type; // copy of disk inode
short major;
uint size;
uint addrs[NDIRECT+1];
};
-#define I_VALID 0x2
// table mapping major device number to
// device functions
// to provide a place for synchronizing access
// to inodes used by multiple processes. The cached
// inodes include book-keeping information that is
-// not stored on disk: ip->ref and ip->flags.
+// not stored on disk: ip->ref and ip->valid.
//
// An inode and its in-memory representation go through a
// sequence of states before they can be used by the
// decrements ref.
//
// * Valid: the information (type, size, &c) in an inode
-// cache entry is only correct when the I_VALID bit
-// is set in ip->flags. ilock() reads the inode from
-// the disk and sets I_VALID, while iput() clears
-// I_VALID if ip->ref has fallen to zero.
+// cache entry is only correct when ip->valid is 1.
+// ilock() reads the inode from
+// the disk and sets ip->valid, while iput() clears
+// ip->valid if ip->ref has fallen to zero.
//
// * Locked: file system code may only examine and modify
// the information in an inode and its content if it
ip->dev = dev;
ip->inum = inum;
ip->ref = 1;
- ip->flags = 0;
+ ip->valid = 0;
release(&icache.lock);
return ip;
acquiresleep(&ip->lock);
- if((ip->flags & I_VALID) == 0){
+ if(ip->valid == 0){
bp = bread(ip->dev, IBLOCK(ip->inum, sb));
dip = (struct dinode*)bp->data + ip->inum%IPB;
ip->type = dip->type;
ip->size = dip->size;
memmove(ip->addrs, dip->addrs, sizeof(ip->addrs));
brelse(bp);
- ip->flags |= I_VALID;
+ ip->valid = 1;
if(ip->type == 0)
panic("ilock: no type");
}
iput(struct inode *ip)
{
acquire(&icache.lock);
- if(ip->ref == 1 && (ip->flags & I_VALID) && ip->nlink == 0){
+ if(ip->ref == 1 && ip->valid && ip->nlink == 0){
// inode has no links and no other references: truncate and free.
acquiresleep(&ip->lock);
release(&icache.lock);
ip->type = 0;
iupdate(ip);
acquire(&icache.lock);
- ip->flags = 0;
+ ip->valid = 0;
releasesleep(&ip->lock);
}
ip->ref--;