ilo-pona/xv6-65oo2
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Activity

fix iput() to more obviously avoid deadlock

Browse source
This commit is contained in:
Robert Morris 2017-08-08 14:19:54 -04:00
parent 1c7aa96005
commit a4ee6f7de3
1 changed files with 9 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
fs.c
View file

@ -329,20 +329,22 @@ iunlock(struct inode *ip)
void
iput(struct inode *ip)
{
acquire(&icache.lock);
if(ip->ref == 1){
acquiresleep(&ip->lock);
if(ip->valid && ip->nlink == 0){
acquiresleep(&ip->lock);
if(ip->valid && ip->nlink == 0){
acquire(&icache.lock);
int r = ip->ref;
release(&icache.lock);
if(r == 1){
// inode has no links and no other references: truncate and free.
release(&icache.lock);
itrunc(ip);
ip->type = 0;
iupdate(ip);
ip->valid = 0;
acquire(&icache.lock);
}
releasesleep(&ip->lock);
}
releasesleep(&ip->lock);
acquire(&icache.lock);
ip->ref--;
release(&icache.lock);
}