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/smp_lock.h> 12 #include <linux/exportfs.h> 13 #include "efs.h" 14 15 16 static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) { 17 struct buffer_head *bh; 18 19 int slot, namelen; 20 char *nameptr; 21 struct efs_dir *dirblock; 22 struct efs_dentry *dirslot; 23 efs_ino_t inodenum; 24 efs_block_t block; 25 26 if (inode->i_size & (EFS_DIRBSIZE-1)) 27 printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n"); 28 29 for(block = 0; block < inode->i_blocks; block++) { 30 31 bh = sb_bread(inode->i_sb, efs_bmap(inode, block)); 32 if (!bh) { 33 printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block); 34 return 0; 35 } 36 37 dirblock = (struct efs_dir *) bh->b_data; 38 39 if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) { 40 printk(KERN_ERR "EFS: find_entry(): invalid directory block\n"); 41 brelse(bh); 42 return(0); 43 } 44 45 for(slot = 0; slot < dirblock->slots; slot++) { 46 dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot)); 47 48 namelen = dirslot->namelen; 49 nameptr = dirslot->name; 50 51 if ((namelen == len) && (!memcmp(name, nameptr, len))) { 52 inodenum = be32_to_cpu(dirslot->inode); 53 brelse(bh); 54 return(inodenum); 55 } 56 } 57 brelse(bh); 58 } 59 return(0); 60 } 61 62 struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { 63 efs_ino_t inodenum; 64 struct inode * inode = NULL; 65 66 lock_kernel(); 67 inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len); 68 if (inodenum) { 69 inode = efs_iget(dir->i_sb, inodenum); 70 if (IS_ERR(inode)) { 71 unlock_kernel(); 72 return ERR_CAST(inode); 73 } 74 } 75 unlock_kernel(); 76 77 return d_splice_alias(inode, dentry); 78 } 79 80 static struct inode *efs_nfs_get_inode(struct super_block *sb, u64 ino, 81 u32 generation) 82 { 83 struct inode *inode; 84 85 if (ino == 0) 86 return ERR_PTR(-ESTALE); 87 inode = efs_iget(sb, ino); 88 if (IS_ERR(inode)) 89 return ERR_CAST(inode); 90 91 if (generation && inode->i_generation != generation) { 92 iput(inode); 93 return ERR_PTR(-ESTALE); 94 } 95 96 return inode; 97 } 98 99 struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid, 100 int fh_len, int fh_type) 101 { 102 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 103 efs_nfs_get_inode); 104 } 105 106 struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid, 107 int fh_len, int fh_type) 108 { 109 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 110 efs_nfs_get_inode); 111 } 112 113 struct dentry *efs_get_parent(struct dentry *child) 114 { 115 struct dentry *parent = ERR_PTR(-ENOENT); 116 efs_ino_t ino; 117 118 lock_kernel(); 119 ino = efs_find_entry(child->d_inode, "..", 2); 120 if (ino) 121 parent = d_obtain_alias(efs_iget(child->d_inode->i_sb, ino)); 122 unlock_kernel(); 123 124 return parent; 125 } 126