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