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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * fs/bfs/dir.c
3 * BFS directory operations.
4 * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
Andrew Stribblehillfac92be2005-09-09 13:02:04 -07005 * Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 */
7
8#include <linux/time.h>
9#include <linux/string.h>
10#include <linux/fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/buffer_head.h>
12#include <linux/sched.h>
13#include "bfs.h"
14
15#undef DEBUG
16
17#ifdef DEBUG
18#define dprintf(x...) printf(x)
19#else
20#define dprintf(x...)
21#endif
22
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080023static int bfs_add_entry(struct inode *dir, const unsigned char *name,
24 int namelen, int ino);
25static struct buffer_head *bfs_find_entry(struct inode *dir,
26 const unsigned char *name, int namelen,
27 struct bfs_dirent **res_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080029static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080031 struct inode *dir = f->f_path.dentry->d_inode;
32 struct buffer_head *bh;
33 struct bfs_dirent *de;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -070034 struct bfs_sb_info *info = BFS_SB(dir->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 unsigned int offset;
36 int block;
37
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -070038 mutex_lock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080040 if (f->f_pos & (BFS_DIRENT_SIZE - 1)) {
41 printf("Bad f_pos=%08lx for %s:%08lx\n",
42 (unsigned long)f->f_pos,
43 dir->i_sb->s_id, dir->i_ino);
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -070044 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 return -EBADF;
46 }
47
48 while (f->f_pos < dir->i_size) {
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080049 offset = f->f_pos & (BFS_BSIZE - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 block = BFS_I(dir)->i_sblock + (f->f_pos >> BFS_BSIZE_BITS);
51 bh = sb_bread(dir->i_sb, block);
52 if (!bh) {
53 f->f_pos += BFS_BSIZE - offset;
54 continue;
55 }
56 do {
57 de = (struct bfs_dirent *)(bh->b_data + offset);
58 if (de->ino) {
59 int size = strnlen(de->name, BFS_NAMELEN);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080060 if (filldir(dirent, de->name, size, f->f_pos,
61 le16_to_cpu(de->ino),
62 DT_UNKNOWN) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 brelse(bh);
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -070064 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 return 0;
66 }
67 }
68 offset += BFS_DIRENT_SIZE;
69 f->f_pos += BFS_DIRENT_SIZE;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080070 } while ((offset < BFS_BSIZE) && (f->f_pos < dir->i_size));
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 brelse(bh);
72 }
73
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -070074 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 return 0;
76}
77
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080078const struct file_operations bfs_dir_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 .read = generic_read_dir,
80 .readdir = bfs_readdir,
Christoph Hellwig1b061d92010-05-26 17:53:41 +020081 .fsync = generic_file_fsync,
Christoph Hellwig3222a3e2008-09-03 21:53:01 +020082 .llseek = generic_file_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -070083};
84
85extern void dump_imap(const char *, struct super_block *);
86
Al Viro4acdaf22011-07-26 01:42:34 -040087static int bfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080088 struct nameidata *nd)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089{
90 int err;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080091 struct inode *inode;
92 struct super_block *s = dir->i_sb;
93 struct bfs_sb_info *info = BFS_SB(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 unsigned long ino;
95
96 inode = new_inode(s);
97 if (!inode)
98 return -ENOSPC;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -070099 mutex_lock(&info->bfs_lock);
Akinobu Mita69b195b2011-03-21 08:32:53 -0400100 ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 if (ino > info->si_lasti) {
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700102 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 iput(inode);
104 return -ENOSPC;
105 }
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800106 set_bit(ino, info->si_imap);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 info->si_freei--;
Dmitry Monakhove6ecdc72010-03-04 17:31:46 +0300108 inode_init_owner(inode, dir, mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
Theodore Ts'oba52de12006-09-27 01:50:49 -0700110 inode->i_blocks = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 inode->i_op = &bfs_file_inops;
112 inode->i_fop = &bfs_file_operations;
113 inode->i_mapping->a_ops = &bfs_aops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 inode->i_ino = ino;
Alexey Dobriyance0fe7e2005-10-04 17:43:06 +0100115 BFS_I(inode)->i_dsk_ino = ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 BFS_I(inode)->i_sblock = 0;
117 BFS_I(inode)->i_eblock = 0;
118 insert_inode_hash(inode);
119 mark_inode_dirty(inode);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800120 dump_imap("create", s);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800122 err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
123 inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 if (err) {
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700125 inode_dec_link_count(inode);
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700126 mutex_unlock(&info->bfs_lock);
Eric Sesterhenn15581822008-09-13 02:33:12 -0700127 iput(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 return err;
129 }
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700130 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 d_instantiate(dentry, inode);
132 return 0;
133}
134
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800135static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
136 struct nameidata *nd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800138 struct inode *inode = NULL;
139 struct buffer_head *bh;
140 struct bfs_dirent *de;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700141 struct bfs_sb_info *info = BFS_SB(dir->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
143 if (dentry->d_name.len > BFS_NAMELEN)
144 return ERR_PTR(-ENAMETOOLONG);
145
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700146 mutex_lock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
148 if (bh) {
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700149 unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 brelse(bh);
David Howellse33ab082008-02-07 00:15:32 -0800151 inode = bfs_iget(dir->i_sb, ino);
152 if (IS_ERR(inode)) {
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700153 mutex_unlock(&info->bfs_lock);
David Howellse33ab082008-02-07 00:15:32 -0800154 return ERR_CAST(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 }
156 }
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700157 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 d_add(dentry, inode);
159 return NULL;
160}
161
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800162static int bfs_link(struct dentry *old, struct inode *dir,
163 struct dentry *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800165 struct inode *inode = old->d_inode;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700166 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 int err;
168
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700169 mutex_lock(&info->bfs_lock);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800170 err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
171 inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 if (err) {
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700173 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 return err;
175 }
Dave Hansend8c76e62006-09-30 23:29:04 -0700176 inc_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 inode->i_ctime = CURRENT_TIME_SEC;
178 mark_inode_dirty(inode);
Al Viro7de9c6e2010-10-23 11:11:40 -0400179 ihold(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 d_instantiate(new, inode);
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700181 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 return 0;
183}
184
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800185static int bfs_unlink(struct inode *dir, struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186{
187 int error = -ENOENT;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700188 struct inode *inode = dentry->d_inode;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800189 struct buffer_head *bh;
190 struct bfs_dirent *de;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700191 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700193 mutex_lock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800195 if (!bh || (le16_to_cpu(de->ino) != inode->i_ino))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 goto out_brelse;
197
198 if (!inode->i_nlink) {
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800199 printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
200 inode->i_sb->s_id, inode->i_ino,
201 inode->i_nlink);
Miklos Szeredibfe86842011-10-28 14:13:29 +0200202 set_nlink(inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 }
204 de->ino = 0;
Al Viro4427f0c2009-06-08 01:15:58 -0400205 mark_buffer_dirty_inode(bh, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
207 mark_inode_dirty(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 inode->i_ctime = dir->i_ctime;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700209 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 error = 0;
211
212out_brelse:
213 brelse(bh);
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700214 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 return error;
216}
217
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800218static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
219 struct inode *new_dir, struct dentry *new_dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800221 struct inode *old_inode, *new_inode;
222 struct buffer_head *old_bh, *new_bh;
223 struct bfs_dirent *old_de, *new_de;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700224 struct bfs_sb_info *info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 int error = -ENOENT;
226
227 old_bh = new_bh = NULL;
228 old_inode = old_dentry->d_inode;
229 if (S_ISDIR(old_inode->i_mode))
230 return -EINVAL;
231
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700232 info = BFS_SB(old_inode->i_sb);
233
234 mutex_lock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 old_bh = bfs_find_entry(old_dir,
236 old_dentry->d_name.name,
237 old_dentry->d_name.len, &old_de);
238
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800239 if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 goto end_rename;
241
242 error = -EPERM;
243 new_inode = new_dentry->d_inode;
244 new_bh = bfs_find_entry(new_dir,
245 new_dentry->d_name.name,
246 new_dentry->d_name.len, &new_de);
247
248 if (new_bh && !new_inode) {
249 brelse(new_bh);
250 new_bh = NULL;
251 }
252 if (!new_bh) {
253 error = bfs_add_entry(new_dir,
254 new_dentry->d_name.name,
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800255 new_dentry->d_name.len,
256 old_inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 if (error)
258 goto end_rename;
259 }
260 old_de->ino = 0;
261 old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
262 mark_inode_dirty(old_dir);
263 if (new_inode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 new_inode->i_ctime = CURRENT_TIME_SEC;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700265 inode_dec_link_count(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 }
Al Viro4427f0c2009-06-08 01:15:58 -0400267 mark_buffer_dirty_inode(old_bh, old_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 error = 0;
269
270end_rename:
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700271 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 brelse(old_bh);
273 brelse(new_bh);
274 return error;
275}
276
Arjan van de Ven754661f2007-02-12 00:55:38 -0800277const struct inode_operations bfs_dir_inops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 .create = bfs_create,
279 .lookup = bfs_lookup,
280 .link = bfs_link,
281 .unlink = bfs_unlink,
282 .rename = bfs_rename,
283};
284
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800285static int bfs_add_entry(struct inode *dir, const unsigned char *name,
286 int namelen, int ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800288 struct buffer_head *bh;
289 struct bfs_dirent *de;
290 int block, sblock, eblock, off, pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 int i;
292
293 dprintf("name=%s, namelen=%d\n", name, namelen);
294
295 if (!namelen)
296 return -ENOENT;
297 if (namelen > BFS_NAMELEN)
298 return -ENAMETOOLONG;
299
300 sblock = BFS_I(dir)->i_sblock;
301 eblock = BFS_I(dir)->i_eblock;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800302 for (block = sblock; block <= eblock; block++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 bh = sb_bread(dir->i_sb, block);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800304 if (!bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 return -ENOSPC;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800306 for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 de = (struct bfs_dirent *)(bh->b_data + off);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 if (!de->ino) {
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800309 pos = (block - sblock) * BFS_BSIZE + off;
310 if (pos >= dir->i_size) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 dir->i_size += BFS_DIRENT_SIZE;
312 dir->i_ctime = CURRENT_TIME_SEC;
313 }
314 dir->i_mtime = CURRENT_TIME_SEC;
315 mark_inode_dirty(dir);
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700316 de->ino = cpu_to_le16((u16)ino);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800317 for (i = 0; i < BFS_NAMELEN; i++)
318 de->name[i] =
319 (i < namelen) ? name[i] : 0;
Al Viro4427f0c2009-06-08 01:15:58 -0400320 mark_buffer_dirty_inode(bh, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 brelse(bh);
322 return 0;
323 }
324 }
325 brelse(bh);
326 }
327 return -ENOSPC;
328}
329
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800330static inline int bfs_namecmp(int len, const unsigned char *name,
331 const char *buffer)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800333 if ((len < BFS_NAMELEN) && buffer[len])
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 return 0;
335 return !memcmp(name, buffer, len);
336}
337
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800338static struct buffer_head *bfs_find_entry(struct inode *dir,
339 const unsigned char *name, int namelen,
340 struct bfs_dirent **res_dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800342 unsigned long block = 0, offset = 0;
343 struct buffer_head *bh = NULL;
344 struct bfs_dirent *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346 *res_dir = NULL;
347 if (namelen > BFS_NAMELEN)
348 return NULL;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800349
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 while (block * BFS_BSIZE + offset < dir->i_size) {
351 if (!bh) {
352 bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
353 if (!bh) {
354 block++;
355 continue;
356 }
357 }
358 de = (struct bfs_dirent *)(bh->b_data + offset);
359 offset += BFS_DIRENT_SIZE;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800360 if (le16_to_cpu(de->ino) &&
361 bfs_namecmp(namelen, name, de->name)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 *res_dir = de;
363 return bh;
364 }
365 if (offset < bh->b_size)
366 continue;
367 brelse(bh);
368 bh = NULL;
369 offset = 0;
370 block++;
371 }
372 brelse(bh);
373 return NULL;
374}