From dec637bc59a23a7676f2ec0c9db10fe8122607df Mon Sep 17 00:00:00 2001 From: Frans Kaashoek Date: Sun, 11 Sep 2016 20:59:57 -0400 Subject: Replace I_BUSY with sleep locks --- fs.c | 27 ++++++++++----------------- 1 file changed, 10 insertions(+), 17 deletions(-) (limited to 'fs.c') diff --git a/fs.c b/fs.c index 26a0b3e..be8c5c5 100644 --- a/fs.c +++ b/fs.c @@ -135,9 +135,7 @@ bfree(int dev, uint b) // // * Locked: file system code may only examine and modify // the information in an inode and its content if it -// has first locked the inode. The I_BUSY flag indicates -// that the inode is locked. ilock() sets I_BUSY, -// while iunlock clears it. +// has first locked the inode. // // Thus a typical sequence is: // ip = iget(dev, inum) @@ -165,7 +163,13 @@ struct { void iinit(int dev) { + int i = 0; + initlock(&icache.lock, "icache"); + for(i = 0; i < NINODE; i++) { + initsleeplock(&icache.inode[i].lock, "inode"); + } + readsb(dev, &sb); cprintf("sb: size %d nblocks %d ninodes %d nlog %d logstart %d\ inodestart %d bmap start %d\n", sb.size, sb.nblocks, @@ -277,11 +281,7 @@ ilock(struct inode *ip) if(ip == 0 || ip->ref < 1) panic("ilock"); - acquire(&icache.lock); - while(ip->flags & I_BUSY) - sleep(ip, &icache.lock); - ip->flags |= I_BUSY; - release(&icache.lock); + acquiresleep(&ip->lock); if(!(ip->flags & I_VALID)){ bp = bread(ip->dev, IBLOCK(ip->inum, sb)); @@ -303,13 +303,10 @@ ilock(struct inode *ip) void iunlock(struct inode *ip) { - if(ip == 0 || !(ip->flags & I_BUSY) || ip->ref < 1) + if(ip == 0 || !holdingsleep(&ip->lock) || ip->ref < 1) panic("iunlock"); - acquire(&icache.lock); - ip->flags &= ~I_BUSY; - wakeup(ip); - release(&icache.lock); + releasesleep(&ip->lock); } // Drop a reference to an in-memory inode. @@ -325,16 +322,12 @@ 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. - if(ip->flags & I_BUSY) - panic("iput busy"); - ip->flags |= I_BUSY; release(&icache.lock); itrunc(ip); ip->type = 0; iupdate(ip); acquire(&icache.lock); ip->flags = 0; - wakeup(ip); } ip->ref--; release(&icache.lock); -- cgit v1.2.3