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111 lines
2.3 KiB
111 lines
2.3 KiB
20 years ago
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/*
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* namei.c
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*
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* Copyright (c) 1999 Al Smith
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*
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* Portions derived from work (c) 1995,1996 Christian Vogelgsang.
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*/
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#include <linux/buffer_head.h>
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#include <linux/string.h>
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#include <linux/efs_fs.h>
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#include <linux/smp_lock.h>
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static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) {
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struct buffer_head *bh;
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int slot, namelen;
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char *nameptr;
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struct efs_dir *dirblock;
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struct efs_dentry *dirslot;
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efs_ino_t inodenum;
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efs_block_t block;
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if (inode->i_size & (EFS_DIRBSIZE-1))
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printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n");
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for(block = 0; block < inode->i_blocks; block++) {
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bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
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if (!bh) {
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printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block);
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return 0;
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}
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dirblock = (struct efs_dir *) bh->b_data;
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if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
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printk(KERN_ERR "EFS: find_entry(): invalid directory block\n");
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brelse(bh);
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return(0);
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}
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for(slot = 0; slot < dirblock->slots; slot++) {
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dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
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namelen = dirslot->namelen;
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nameptr = dirslot->name;
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if ((namelen == len) && (!memcmp(name, nameptr, len))) {
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inodenum = be32_to_cpu(dirslot->inode);
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brelse(bh);
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return(inodenum);
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}
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}
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brelse(bh);
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}
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return(0);
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}
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struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) {
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efs_ino_t inodenum;
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struct inode * inode = NULL;
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lock_kernel();
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inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
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if (inodenum) {
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if (!(inode = iget(dir->i_sb, inodenum))) {
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unlock_kernel();
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return ERR_PTR(-EACCES);
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}
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}
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unlock_kernel();
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d_add(dentry, inode);
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return NULL;
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}
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struct dentry *efs_get_parent(struct dentry *child)
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{
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struct dentry *parent;
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struct inode *inode;
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efs_ino_t ino;
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int error;
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lock_kernel();
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error = -ENOENT;
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ino = efs_find_entry(child->d_inode, "..", 2);
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if (!ino)
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goto fail;
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error = -EACCES;
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inode = iget(child->d_inode->i_sb, ino);
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if (!inode)
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goto fail;
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error = -ENOMEM;
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parent = d_alloc_anon(inode);
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if (!parent)
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goto fail_iput;
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unlock_kernel();
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return parent;
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fail_iput:
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iput(inode);
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fail:
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unlock_kernel();
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return ERR_PTR(error);
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}
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