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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * dir.c | |
3 | * | |
4 | * Copyright (c) 1999 Al Smith | |
5 | */ | |
6 | ||
7 | #include <linux/buffer_head.h> | |
45254b4f | 8 | #include "efs.h" |
1da177e4 | 9 | |
7aa123a0 | 10 | static int efs_readdir(struct file *, struct dir_context *); |
1da177e4 | 11 | |
4b6f5d20 | 12 | const struct file_operations efs_dir_operations = { |
e7ec952f | 13 | .llseek = generic_file_llseek, |
1da177e4 | 14 | .read = generic_read_dir, |
7aa123a0 | 15 | .iterate = efs_readdir, |
1da177e4 LT |
16 | }; |
17 | ||
754661f1 | 18 | const struct inode_operations efs_dir_inode_operations = { |
1da177e4 LT |
19 | .lookup = efs_lookup, |
20 | }; | |
21 | ||
7aa123a0 AV |
22 | static int efs_readdir(struct file *file, struct dir_context *ctx) |
23 | { | |
24 | struct inode *inode = file_inode(file); | |
1da177e4 | 25 | efs_block_t block; |
7aa123a0 | 26 | int slot; |
1da177e4 LT |
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 | ||
1da177e4 | 31 | /* work out where this entry can be found */ |
7aa123a0 | 32 | block = ctx->pos >> EFS_DIRBSIZE_BITS; |
1da177e4 LT |
33 | |
34 | /* each block contains at most 256 slots */ | |
7aa123a0 | 35 | slot = ctx->pos & 0xff; |
1da177e4 LT |
36 | |
37 | /* look at all blocks */ | |
38 | while (block < inode->i_blocks) { | |
7aa123a0 AV |
39 | struct efs_dir *dirblock; |
40 | struct buffer_head *bh; | |
41 | ||
1da177e4 LT |
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 | ||
7aa123a0 AV |
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) | |
1da177e4 | 65 | continue; |
1da177e4 LT |
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 | |
7aa123a0 AV |
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)) { | |
1da177e4 | 89 | brelse(bh); |
7aa123a0 | 90 | return 0; |
1da177e4 | 91 | } |
1da177e4 LT |
92 | } |
93 | brelse(bh); | |
94 | ||
95 | slot = 0; | |
96 | block++; | |
97 | } | |
7aa123a0 | 98 | ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot; |
1da177e4 LT |
99 | return 0; |
100 | } | |
101 |