[ALSA] Add even more 'const' to everything related to TLV
[linux-2.6.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 <linux/efs_fs.h>
9 #include <linux/smp_lock.h>
10
11 static int efs_readdir(struct file *, void *, filldir_t);
12
13 const struct file_operations efs_dir_operations = {
14         .read           = generic_read_dir,
15         .readdir        = efs_readdir,
16 };
17
18 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         lock_kernel();
37
38         /* work out where this entry can be found */
39         block = filp->f_pos >> EFS_DIRBSIZE_BITS;
40
41         /* each block contains at most 256 slots */
42         slot  = filp->f_pos & 0xff;
43
44         /* look at all blocks */
45         while (block < inode->i_blocks) {
46                 /* read the dir block */
47                 bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
48
49                 if (!bh) {
50                         printk(KERN_ERR "EFS: readdir(): failed to read dir block %d\n", block);
51                         break;
52                 }
53
54                 dirblock = (struct efs_dir *) bh->b_data; 
55
56                 if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
57                         printk(KERN_ERR "EFS: readdir(): invalid directory block\n");
58                         brelse(bh);
59                         break;
60                 }
61
62                 while (slot < dirblock->slots) {
63                         if (dirblock->space[slot] == 0) {
64                                 slot++;
65                                 continue;
66                         }
67
68                         dirslot  = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
69
70                         inodenum = be32_to_cpu(dirslot->inode);
71                         namelen  = dirslot->namelen;
72                         nameptr  = dirslot->name;
73
74 #ifdef DEBUG
75                         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);
76 #endif
77                         if (namelen > 0) {
78                                 /* found the next entry */
79                                 filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
80
81                                 /* copy filename and data in dirslot */
82                                 filldir(dirent, nameptr, namelen, filp->f_pos, inodenum, DT_UNKNOWN);
83
84                                 /* sanity check */
85                                 if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) {
86                                         printk(KERN_WARNING "EFS: directory entry %d exceeds directory block\n", slot);
87                                         slot++;
88                                         continue;
89                                 }
90
91                                 /* store position of next slot */
92                                 if (++slot == dirblock->slots) {
93                                         slot = 0;
94                                         block++;
95                                 }
96                                 brelse(bh);
97                                 filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
98                                 goto out;
99                         }
100                         slot++;
101                 }
102                 brelse(bh);
103
104                 slot = 0;
105                 block++;
106         }
107
108         filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
109 out:
110         unlock_kernel();
111         return 0;
112 }
113