103 lines
2.5 KiB
C
103 lines
2.5 KiB
C
/*
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* super.c contains code to handle the super-block tables.
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*/
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#include <linux/config.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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/* set_bit uses setb, as gas doesn't recognize setc */
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#define set_bit(bitnr,addr) ({ \
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register int __res __asm__("ax"); \
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__asm__("bt %2,%3;setb %%al":"=a" (__res):"a" (0),"r" (bitnr),"m" (*(addr))); \
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__res; })
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struct super_block super_block[NR_SUPER];
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struct super_block * do_mount(int dev)
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{
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struct super_block * p;
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struct buffer_head * bh;
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int i,block;
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for(p = &super_block[0] ; p < &super_block[NR_SUPER] ; p++ )
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if (!(p->s_dev))
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break;
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p->s_dev = -1; /* mark it in use */
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if (p >= &super_block[NR_SUPER])
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return NULL;
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if (!(bh = bread(dev,1)))
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return NULL;
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*p = *((struct super_block *) bh->b_data);
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brelse(bh);
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if (p->s_magic != SUPER_MAGIC) {
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p->s_dev = 0;
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return NULL;
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}
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for (i=0;i<I_MAP_SLOTS;i++)
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p->s_imap[i] = NULL;
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for (i=0;i<Z_MAP_SLOTS;i++)
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p->s_zmap[i] = NULL;
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block=2;
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for (i=0 ; i < p->s_imap_blocks ; i++)
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if (p->s_imap[i]=bread(dev,block))
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block++;
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else
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break;
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for (i=0 ; i < p->s_zmap_blocks ; i++)
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if (p->s_zmap[i]=bread(dev,block))
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block++;
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else
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break;
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if (block != 2+p->s_imap_blocks+p->s_zmap_blocks) {
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for(i=0;i<I_MAP_SLOTS;i++)
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brelse(p->s_imap[i]);
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for(i=0;i<Z_MAP_SLOTS;i++)
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brelse(p->s_zmap[i]);
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p->s_dev=0;
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return NULL;
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}
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p->s_imap[0]->b_data[0] |= 1;
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p->s_zmap[0]->b_data[0] |= 1;
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p->s_dev = dev;
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p->s_isup = NULL;
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p->s_imount = NULL;
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p->s_time = 0;
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p->s_rd_only = 0;
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p->s_dirt = 0;
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return p;
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}
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void mount_root(void)
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{
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int i,free;
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struct super_block * p;
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struct m_inode * mi;
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if (32 != sizeof (struct d_inode))
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panic("bad i-node size");
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for(i=0;i<NR_FILE;i++)
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file_table[i].f_count=0;
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for(p = &super_block[0] ; p < &super_block[NR_SUPER] ; p++)
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p->s_dev = 0;
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if (!(p=do_mount(ROOT_DEV)))
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panic("Unable to mount root");
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if (!(mi=iget(ROOT_DEV,1)))
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panic("Unable to read root i-node");
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mi->i_count += 3 ; /* NOTE! it is logically used 4 times, not 1 */
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p->s_isup = p->s_imount = mi;
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current->pwd = mi;
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current->root = mi;
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free=0;
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i=p->s_nzones;
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while (-- i >= 0)
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if (!set_bit(i&8191,p->s_zmap[i>>13]->b_data))
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free++;
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printk("%d/%d free blocks\n\r",free,p->s_nzones);
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free=0;
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i=p->s_ninodes+1;
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while (-- i >= 0)
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if (!set_bit(i&8191,p->s_imap[i>>13]->b_data))
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free++;
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printk("%d/%d free inodes\n\r",free,p->s_ninodes);
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}
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