diff options
| -rw-r--r-- | fs.c | 16 |
1 files changed, 9 insertions, 7 deletions
@@ -112,20 +112,20 @@ bfree(int dev, uint b) // inodes include book-keeping information that is // not stored on disk: ip->ref and ip->flags. // -// An inode and its in-memory represtative go through a +// An inode and its in-memory representation go through a // sequence of states before they can be used by the // rest of the file system code. // // * Allocation: an inode is allocated if its type (on disk) -// is non-zero. ialloc() allocates, iput() frees if -// the link count has fallen to zero. +// is non-zero. ialloc() allocates, and iput() frees if +// the reference and link counts have fallen to zero. // // * Referencing in cache: an entry in the inode cache // is free if ip->ref is zero. Otherwise ip->ref tracks // the number of in-memory pointers to the entry (open -// files and current directories). iget() to find or -// create a cache entry and increment its ref, iput() -// to decrement ref. +// files and current directories). iget() finds or +// creates a cache entry and increments its ref; iput() +// decrements ref. // // * Valid: the information (type, size, &c) in an inode // cache entry is only correct when the I_VALID bit @@ -283,7 +283,7 @@ ilock(struct inode *ip) acquiresleep(&ip->lock); - if(!(ip->flags & I_VALID)){ + if((ip->flags & I_VALID) == 0){ bp = bread(ip->dev, IBLOCK(ip->inum, sb)); dip = (struct dinode*)bp->data + ip->inum%IPB; ip->type = dip->type; @@ -322,12 +322,14 @@ iput(struct inode *ip) acquire(&icache.lock); if(ip->ref == 1 && (ip->flags & I_VALID) && ip->nlink == 0){ // inode has no links and no other references: truncate and free. + acquiresleep(&ip->lock); release(&icache.lock); itrunc(ip); ip->type = 0; iupdate(ip); acquire(&icache.lock); ip->flags = 0; + releasesleep(&ip->lock); } ip->ref--; release(&icache.lock); |