fs/efs/namei.c

   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 <<<<<<< HEAD:fs/efs/namei.c
  12 #include <linux/efs_fs.h>
  13 =======
  14 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:fs/efs/namei.c
  15 #include <linux/smp_lock.h>
  16 #include <linux/exportfs.h>
  17 <<<<<<< HEAD:fs/efs/namei.c
  18 =======
  19 #include "efs.h"
  20 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:fs/efs/namei.c
  21
  22
  23 static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) {
  24         struct buffer_head *bh;
  25
  26         int                     slot, namelen;
  27         char                    *nameptr;
  28         struct efs_dir          *dirblock;
  29         struct efs_dentry       *dirslot;
  30         efs_ino_t               inodenum;
  31         efs_block_t             block;
  32
  33         if (inode->i_size & (EFS_DIRBSIZE-1))
  34                 printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n");
  35
  36         for(block = 0; block < inode->i_blocks; block++) {
  37
  38                 bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
  39                 if (!bh) {
  40                         printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block);
  41                         return 0;
  42                 }
  43
  44                 dirblock = (struct efs_dir *) bh->b_data;
  45
  46                 if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
  47                         printk(KERN_ERR "EFS: find_entry(): invalid directory block\n");
  48                         brelse(bh);
  49                         return(0);
  50                 }
  51
  52                 for(slot = 0; slot < dirblock->slots; slot++) {
  53                         dirslot  = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
  54
  55                         namelen  = dirslot->namelen;
  56                         nameptr  = dirslot->name;
  57
  58                         if ((namelen == len) && (!memcmp(name, nameptr, len))) {
  59                                 inodenum = be32_to_cpu(dirslot->inode);
  60                                 brelse(bh);
  61                                 return(inodenum);
  62                         }
  63                 }
  64                 brelse(bh);
  65         }
  66         return(0);
  67 }
  68
  69 struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) {
  70         efs_ino_t inodenum;
  71         struct inode * inode = NULL;
  72
  73         lock_kernel();
  74         inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
  75         if (inodenum) {
  76                 inode = efs_iget(dir->i_sb, inodenum);
  77                 if (IS_ERR(inode)) {
  78                         unlock_kernel();
  79                         return ERR_CAST(inode);
  80                 }
  81         }
  82         unlock_kernel();
  83
  84         d_add(dentry, inode);
  85         return NULL;
  86 }
  87
  88 static struct inode *efs_nfs_get_inode(struct super_block *sb, u64 ino,
  89                 u32 generation)
  90 {
  91         struct inode *inode;
  92
  93         if (ino == 0)
  94                 return ERR_PTR(-ESTALE);
  95         inode = efs_iget(sb, ino);
  96         if (IS_ERR(inode))
  97                 return ERR_CAST(inode);
  98
  99         if (generation && inode->i_generation != generation) {
 100                 iput(inode);
 101                 return ERR_PTR(-ESTALE);
 102         }
 103
 104         return inode;
 105 }
 106
 107 struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid,
 108                 int fh_len, int fh_type)
 109 {
 110         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 111                                     efs_nfs_get_inode);
 112 }
 113
 114 struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
 115                 int fh_len, int fh_type)
 116 {
 117         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 118                                     efs_nfs_get_inode);
 119 }
 120
 121 struct dentry *efs_get_parent(struct dentry *child)
 122 {
 123         struct dentry *parent;
 124         struct inode *inode;
 125         efs_ino_t ino;
 126         long error;
 127
 128         lock_kernel();
 129
 130         error = -ENOENT;
 131         ino = efs_find_entry(child->d_inode, "..", 2);
 132         if (!ino)
 133                 goto fail;
 134
 135         inode = efs_iget(child->d_inode->i_sb, ino);
 136         if (IS_ERR(inode)) {
 137                 error = PTR_ERR(inode);
 138                 goto fail;
 139         }
 140
 141         error = -ENOMEM;
 142         parent = d_alloc_anon(inode);
 143         if (!parent)
 144                 goto fail_iput;
 145
 146         unlock_kernel();
 147         return parent;
 148
 149  fail_iput:
 150         iput(inode);
 151  fail:
 152         unlock_kernel();
 153         return ERR_PTR(error);
 154 }