sanchayanmaity/xv6-cs450
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Compare commits

base: sanchayanmaity:inc-max-file-size
Branches Tags
sanchayanmaity:master
sanchayanmaity:inc-max-file-size
sanchayanmaity:add_sys_call_getcount
..
compare: sanchayanmaity:master
Branches Tags
sanchayanmaity:inc-max-file-size
sanchayanmaity:add_sys_call_getcount
sanchayanmaity:master

No commits in common. "inc-max-file-size" and "master" have entirely different histories.
inc-max-fi ... master

3 changed files with 6 additions and 46 deletions
Show stats Expand all files Collapse all files

2
file.h
View file

@ -21,7 +21,7 @@ struct inode {
short minor;
short nlink;
uint size;
uint addrs[NDIRECT+3];
uint addrs[NDIRECT+1];
};
#define I_BUSY 0x1
#define I_VALID 0x2

44
fs.c
View file

@ -356,25 +356,18 @@ iunlockput(struct inode *ip)
static uint
bmap(struct inode *ip, uint bn)
{
uint addr, *a, i;
uint addr, *a;
struct buf *bp;
// We use 10 direct, two indirect and one double indirect pointer
if(bn < NDIRECT){
// If block number is less than direct pointers available
// allocate a disk block if not allocated/available
// then return the address of the block
if((addr = ip->addrs[bn]) == 0)
ip->addrs[bn] = addr = balloc(ip->dev);
return addr;
}
// The block number does not fall in the first 10 direct blocks
// Substract the number from the passed block number
bn -= NDIRECT;
if(bn < NINDIRECT){
// Load indirect block, allocating if necessary.
// This is the first indirect block range
if((addr = ip->addrs[NDIRECT]) == 0)
ip->addrs[NDIRECT] = addr = balloc(ip->dev);
bp = bread(ip->dev, addr);
@ -385,39 +378,6 @@ bmap(struct inode *ip, uint bn)
}
brelse(bp);
return addr;
} else if(bn < NINDIRECT * 2){
bn -= NINDIRECT;
// Load indirect block, allocating if necessary.
// This is the second indirect block range
if((addr = ip->addrs[NDIRECT+1]) == 0)
ip->addrs[NDIRECT+1] = addr = balloc(ip->dev);
bp = bread(ip->dev, addr);
a = (uint*)bp->data;
if((addr = a[bn]) == 0){
a[bn] = addr = balloc(ip->dev);
log_write(bp);
}
brelse(bp);
return addr;
} else {
// We are now in the double indirect block range
bn -= NINDIRECT * 2;
// Load indirect block, allocating if necessary.
if((addr = ip->addrs[NDIRECT+2]) == 0)
ip->addrs[NDIRECT+2] = addr = balloc(ip->dev);
bp = bread(ip->dev, addr);
a = (uint*)bp->data;
// This last double indirect block should contain addresses to
// other blocks and not data. Fig 6.4 of xv6 booklet
for (i = 0; i < BSIZE/4; i++){
if((addr = a[i]) == 0){
a[bn] = addr = balloc(ip->dev);
log_write(bp);
break;
}
}
brelse(bp);
return addr;
}
panic("bmap: out of range");
@ -441,7 +401,7 @@ itrunc(struct inode *ip)
ip->addrs[i] = 0;
}
}
if(ip->addrs[NDIRECT]){
bp = bread(ip->dev, ip->addrs[NDIRECT]);
a = (uint*)bp->data;

6
fs.h
View file

@ -19,9 +19,9 @@ struct superblock {
uint nlog; // Number of log blocks
};
#define NDIRECT 10
#define NDIRECT 12
#define NINDIRECT (BSIZE / sizeof(uint))
#define MAXFILE (NDIRECT + 2 * NINDIRECT + NINDIRECT * NINDIRECT)
#define MAXFILE (NDIRECT + NINDIRECT)
// On-disk inode structure
struct dinode {
@ -30,7 +30,7 @@ struct dinode {
short minor; // Minor device number (T_DEV only)
short nlink; // Number of links to inode in file system
uint size; // Size of file (bytes)
uint addrs[NDIRECT+3]; // Data block addresses
uint addrs[NDIRECT+1]; // Data block addresses
};
// Inodes per block.