Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[pandora-kernel.git] / fs / efs / dir.c
1 /*
2  * dir.c
3  *
4  * Copyright (c) 1999 Al Smith
5  */
6
7 #include <linux/buffer_head.h>
8 #include "efs.h"
9
10 static int efs_readdir(struct file *, void *, filldir_t);
11
12 const struct file_operations efs_dir_operations = {
13         .llseek         = generic_file_llseek,
14         .read           = generic_read_dir,
15         .readdir        = efs_readdir,
16 };
17
18 const struct inode_operations efs_dir_inode_operations = {
19         .lookup         = efs_lookup,
20 };
21
22 static int efs_readdir(struct file *filp, void *dirent, filldir_t filldir) {
23         struct inode *inode = filp->f_path.dentry->d_inode;
24         struct buffer_head *bh;
25
26         struct efs_dir          *dirblock;
27         struct efs_dentry       *dirslot;
28         efs_ino_t               inodenum;
29         efs_block_t             block;
30         int                     slot, namelen;
31         char                    *nameptr;
32
33         if (inode->i_size & (EFS_DIRBSIZE-1))
34                 printk(KERN_WARNING "EFS: WARNING: readdir(): directory size not a multiple of EFS_DIRBSIZE\n");
35
36         /* work out where this entry can be found */
37         block = filp->f_pos >> EFS_DIRBSIZE_BITS;
38
39         /* each block contains at most 256 slots */
40         slot  = filp->f_pos & 0xff;
41
42         /* look at all blocks */
43         while (block < inode->i_blocks) {
44                 /* read the dir block */
45                 bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
46
47                 if (!bh) {
48                         printk(KERN_ERR "EFS: readdir(): failed to read dir block %d\n", block);
49                         break;
50                 }
51
52                 dirblock = (struct efs_dir *) bh->b_data; 
53
54                 if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
55                         printk(KERN_ERR "EFS: readdir(): invalid directory block\n");
56                         brelse(bh);
57                         break;
58                 }
59
60                 while (slot < dirblock->slots) {
61                         if (dirblock->space[slot] == 0) {
62                                 slot++;
63                                 continue;
64                         }
65
66                         dirslot  = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
67
68                         inodenum = be32_to_cpu(dirslot->inode);
69                         namelen  = dirslot->namelen;
70                         nameptr  = dirslot->name;
71
72 #ifdef DEBUG
73                         printk(KERN_DEBUG "EFS: readdir(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n", block, slot, dirblock->slots-1, inodenum, nameptr, namelen);
74 #endif
75                         if (namelen > 0) {
76                                 /* found the next entry */
77                                 filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
78
79                                 /* copy filename and data in dirslot */
80                                 filldir(dirent, nameptr, namelen, filp->f_pos, inodenum, DT_UNKNOWN);
81
82                                 /* sanity check */
83                                 if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) {
84                                         printk(KERN_WARNING "EFS: directory entry %d exceeds directory block\n", slot);
85                                         slot++;
86                                         continue;
87                                 }
88
89                                 /* store position of next slot */
90                                 if (++slot == dirblock->slots) {
91                                         slot = 0;
92                                         block++;
93                                 }
94                                 brelse(bh);
95                                 filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
96                                 goto out;
97                         }
98                         slot++;
99                 }
100                 brelse(bh);
101
102                 slot = 0;
103                 block++;
104         }
105
106         filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
107 out:
108         return 0;
109 }
110