| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * namei.c |
| 3 | * |
| 4 | * Copyright (c) 1999 Al Smith |
| 5 | * |
| 6 | * Portions derived from work (c) 1995,1996 Christian Vogelgsang. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/buffer_head.h> |
| 10 | #include <linux/string.h> |
| 11 | #include <linux/efs_fs.h> |
| 12 | #include <linux/smp_lock.h> |
| 13 | |
| 14 | static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) { |
| 15 | struct buffer_head *bh; |
| 16 | |
| 17 | int slot, namelen; |
| 18 | char *nameptr; |
| 19 | struct efs_dir *dirblock; |
| 20 | struct efs_dentry *dirslot; |
| 21 | efs_ino_t inodenum; |
| 22 | efs_block_t block; |
| 23 | |
| 24 | if (inode->i_size & (EFS_DIRBSIZE-1)) |
| 25 | printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n"); |
| 26 | |
| 27 | for(block = 0; block < inode->i_blocks; block++) { |
| 28 | |
| 29 | bh = sb_bread(inode->i_sb, efs_bmap(inode, block)); |
| 30 | if (!bh) { |
| 31 | printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block); |
| 32 | return 0; |
| 33 | } |
| 34 | |
| 35 | dirblock = (struct efs_dir *) bh->b_data; |
| 36 | |
| 37 | if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) { |
| 38 | printk(KERN_ERR "EFS: find_entry(): invalid directory block\n"); |
| 39 | brelse(bh); |
| 40 | return(0); |
| 41 | } |
| 42 | |
| 43 | for(slot = 0; slot < dirblock->slots; slot++) { |
| 44 | dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot)); |
| 45 | |
| 46 | namelen = dirslot->namelen; |
| 47 | nameptr = dirslot->name; |
| 48 | |
| 49 | if ((namelen == len) && (!memcmp(name, nameptr, len))) { |
| 50 | inodenum = be32_to_cpu(dirslot->inode); |
| 51 | brelse(bh); |
| 52 | return(inodenum); |
| 53 | } |
| 54 | } |
| 55 | brelse(bh); |
| 56 | } |
| 57 | return(0); |
| 58 | } |
| 59 | |
| 60 | struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { |
| 61 | efs_ino_t inodenum; |
| 62 | struct inode * inode = NULL; |
| 63 | |
| 64 | lock_kernel(); |
| 65 | inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len); |
| 66 | if (inodenum) { |
| 67 | if (!(inode = iget(dir->i_sb, inodenum))) { |
| 68 | unlock_kernel(); |
| 69 | return ERR_PTR(-EACCES); |
| 70 | } |
| 71 | } |
| 72 | unlock_kernel(); |
| 73 | |
| 74 | d_add(dentry, inode); |
| 75 | return NULL; |
| 76 | } |
| 77 | |
| 78 | struct dentry *efs_get_parent(struct dentry *child) |
| 79 | { |
| 80 | struct dentry *parent; |
| 81 | struct inode *inode; |
| 82 | efs_ino_t ino; |
| 83 | int error; |
| 84 | |
| 85 | lock_kernel(); |
| 86 | |
| 87 | error = -ENOENT; |
| 88 | ino = efs_find_entry(child->d_inode, "..", 2); |
| 89 | if (!ino) |
| 90 | goto fail; |
| 91 | |
| 92 | error = -EACCES; |
| 93 | inode = iget(child->d_inode->i_sb, ino); |
| 94 | if (!inode) |
| 95 | goto fail; |
| 96 | |
| 97 | error = -ENOMEM; |
| 98 | parent = d_alloc_anon(inode); |
| 99 | if (!parent) |
| 100 | goto fail_iput; |
| 101 | |
| 102 | unlock_kernel(); |
| 103 | return parent; |
| 104 | |
| 105 | fail_iput: |
| 106 | iput(inode); |
| 107 | fail: |
| 108 | unlock_kernel(); |
| 109 | return ERR_PTR(error); |
| 110 | } |