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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
Al Viro81b9f662013-05-16 13:41:48 -040029static int bfs_readdir(struct file *f, struct dir_context *ctx)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030{
Al Viro496ad9a2013-01-23 17:07:38 -050031 struct inode *dir = file_inode(f);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080032 struct buffer_head *bh;
33 struct bfs_dirent *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 unsigned int offset;
35 int block;
36
Al Viro81b9f662013-05-16 13:41:48 -040037 if (ctx->pos & (BFS_DIRENT_SIZE - 1)) {
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080038 printf("Bad f_pos=%08lx for %s:%08lx\n",
Al Viro81b9f662013-05-16 13:41:48 -040039 (unsigned long)ctx->pos,
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080040 dir->i_sb->s_id, dir->i_ino);
Al Viro81b9f662013-05-16 13:41:48 -040041 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 }
43
Al Viro81b9f662013-05-16 13:41:48 -040044 while (ctx->pos < dir->i_size) {
45 offset = ctx->pos & (BFS_BSIZE - 1);
46 block = BFS_I(dir)->i_sblock + (ctx->pos >> BFS_BSIZE_BITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 bh = sb_bread(dir->i_sb, block);
48 if (!bh) {
Al Viro81b9f662013-05-16 13:41:48 -040049 ctx->pos += BFS_BSIZE - offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 continue;
51 }
52 do {
53 de = (struct bfs_dirent *)(bh->b_data + offset);
54 if (de->ino) {
55 int size = strnlen(de->name, BFS_NAMELEN);
Al Viro81b9f662013-05-16 13:41:48 -040056 if (!dir_emit(ctx, de->name, size,
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080057 le16_to_cpu(de->ino),
Al Viro81b9f662013-05-16 13:41:48 -040058 DT_UNKNOWN)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 return 0;
61 }
62 }
63 offset += BFS_DIRENT_SIZE;
Al Viro81b9f662013-05-16 13:41:48 -040064 ctx->pos += BFS_DIRENT_SIZE;
65 } while ((offset < BFS_BSIZE) && (ctx->pos < dir->i_size));
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 brelse(bh);
67 }
Al Viro81b9f662013-05-16 13:41:48 -040068 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069}
70
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080071const struct file_operations bfs_dir_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 .read = generic_read_dir,
Al Viroc51da202016-04-30 22:37:34 -040073 .iterate_shared = bfs_readdir,
Christoph Hellwig1b061d92010-05-26 17:53:41 +020074 .fsync = generic_file_fsync,
Christoph Hellwig3222a3e2008-09-03 21:53:01 +020075 .llseek = generic_file_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -070076};
77
Al Viro4acdaf22011-07-26 01:42:34 -040078static int bfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
Al Viroebfc3b42012-06-10 18:05:36 -040079 bool excl)
Linus Torvalds1da177e2005-04-16 15:20:36 -070080{
81 int err;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080082 struct inode *inode;
83 struct super_block *s = dir->i_sb;
84 struct bfs_sb_info *info = BFS_SB(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 unsigned long ino;
86
87 inode = new_inode(s);
88 if (!inode)
Sanidhya Kashyapc3fe5872015-04-16 12:48:32 -070089 return -ENOMEM;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -070090 mutex_lock(&info->bfs_lock);
Akinobu Mita69b195b2011-03-21 08:32:53 -040091 ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 if (ino > info->si_lasti) {
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -070093 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 iput(inode);
95 return -ENOSPC;
96 }
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080097 set_bit(ino, info->si_imap);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 info->si_freei--;
Dmitry Monakhove6ecdc72010-03-04 17:31:46 +030099 inode_init_owner(inode, dir, mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
Theodore Ts'oba52de12006-09-27 01:50:49 -0700101 inode->i_blocks = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 inode->i_op = &bfs_file_inops;
103 inode->i_fop = &bfs_file_operations;
104 inode->i_mapping->a_ops = &bfs_aops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 inode->i_ino = ino;
Alexey Dobriyance0fe7e2005-10-04 17:43:06 +0100106 BFS_I(inode)->i_dsk_ino = ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 BFS_I(inode)->i_sblock = 0;
108 BFS_I(inode)->i_eblock = 0;
109 insert_inode_hash(inode);
110 mark_inode_dirty(inode);
Fabian Frederick1da85fd2014-08-08 14:22:29 -0700111 bfs_dump_imap("create", s);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800113 err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
114 inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 if (err) {
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700116 inode_dec_link_count(inode);
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700117 mutex_unlock(&info->bfs_lock);
Eric Sesterhenn15581822008-09-13 02:33:12 -0700118 iput(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 return err;
120 }
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700121 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 d_instantiate(dentry, inode);
123 return 0;
124}
125
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800126static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
Al Viro00cd8dd2012-06-10 17:13:09 -0400127 unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800129 struct inode *inode = NULL;
130 struct buffer_head *bh;
131 struct bfs_dirent *de;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700132 struct bfs_sb_info *info = BFS_SB(dir->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
134 if (dentry->d_name.len > BFS_NAMELEN)
135 return ERR_PTR(-ENAMETOOLONG);
136
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700137 mutex_lock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
139 if (bh) {
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700140 unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 brelse(bh);
David Howellse33ab082008-02-07 00:15:32 -0800142 inode = bfs_iget(dir->i_sb, ino);
143 if (IS_ERR(inode)) {
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700144 mutex_unlock(&info->bfs_lock);
David Howellse33ab082008-02-07 00:15:32 -0800145 return ERR_CAST(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 }
147 }
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700148 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 d_add(dentry, inode);
150 return NULL;
151}
152
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800153static int bfs_link(struct dentry *old, struct inode *dir,
154 struct dentry *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155{
David Howells2b0143b2015-03-17 22:25:59 +0000156 struct inode *inode = d_inode(old);
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700157 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 int err;
159
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700160 mutex_lock(&info->bfs_lock);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800161 err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
162 inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 if (err) {
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700164 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 return err;
166 }
Dave Hansend8c76e62006-09-30 23:29:04 -0700167 inc_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 inode->i_ctime = CURRENT_TIME_SEC;
169 mark_inode_dirty(inode);
Al Viro7de9c6ee2010-10-23 11:11:40 -0400170 ihold(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 d_instantiate(new, inode);
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700172 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 return 0;
174}
175
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800176static int bfs_unlink(struct inode *dir, struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177{
178 int error = -ENOENT;
David Howells2b0143b2015-03-17 22:25:59 +0000179 struct inode *inode = d_inode(dentry);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800180 struct buffer_head *bh;
181 struct bfs_dirent *de;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700182 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700184 mutex_lock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800186 if (!bh || (le16_to_cpu(de->ino) != inode->i_ino))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 goto out_brelse;
188
189 if (!inode->i_nlink) {
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800190 printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
191 inode->i_sb->s_id, inode->i_ino,
192 inode->i_nlink);
Miklos Szeredibfe86842011-10-28 14:13:29 +0200193 set_nlink(inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 }
195 de->ino = 0;
Al Viro4427f0c2009-06-08 01:15:58 -0400196 mark_buffer_dirty_inode(bh, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
198 mark_inode_dirty(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 inode->i_ctime = dir->i_ctime;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700200 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 error = 0;
202
203out_brelse:
204 brelse(bh);
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700205 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 return error;
207}
208
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800209static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
210 struct inode *new_dir, struct dentry *new_dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800212 struct inode *old_inode, *new_inode;
213 struct buffer_head *old_bh, *new_bh;
214 struct bfs_dirent *old_de, *new_de;
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700215 struct bfs_sb_info *info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 int error = -ENOENT;
217
218 old_bh = new_bh = NULL;
David Howells2b0143b2015-03-17 22:25:59 +0000219 old_inode = d_inode(old_dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 if (S_ISDIR(old_inode->i_mode))
221 return -EINVAL;
222
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700223 info = BFS_SB(old_inode->i_sb);
224
225 mutex_lock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 old_bh = bfs_find_entry(old_dir,
227 old_dentry->d_name.name,
228 old_dentry->d_name.len, &old_de);
229
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800230 if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 goto end_rename;
232
233 error = -EPERM;
David Howells2b0143b2015-03-17 22:25:59 +0000234 new_inode = d_inode(new_dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 new_bh = bfs_find_entry(new_dir,
236 new_dentry->d_name.name,
237 new_dentry->d_name.len, &new_de);
238
239 if (new_bh && !new_inode) {
240 brelse(new_bh);
241 new_bh = NULL;
242 }
243 if (!new_bh) {
244 error = bfs_add_entry(new_dir,
245 new_dentry->d_name.name,
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800246 new_dentry->d_name.len,
247 old_inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 if (error)
249 goto end_rename;
250 }
251 old_de->ino = 0;
252 old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
253 mark_inode_dirty(old_dir);
254 if (new_inode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 new_inode->i_ctime = CURRENT_TIME_SEC;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700256 inode_dec_link_count(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 }
Al Viro4427f0c2009-06-08 01:15:58 -0400258 mark_buffer_dirty_inode(old_bh, old_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 error = 0;
260
261end_rename:
Dmitri Vorobiev3f165e42008-07-25 19:44:54 -0700262 mutex_unlock(&info->bfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 brelse(old_bh);
264 brelse(new_bh);
265 return error;
266}
267
Arjan van de Ven754661f2007-02-12 00:55:38 -0800268const struct inode_operations bfs_dir_inops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 .create = bfs_create,
270 .lookup = bfs_lookup,
271 .link = bfs_link,
272 .unlink = bfs_unlink,
273 .rename = bfs_rename,
274};
275
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800276static int bfs_add_entry(struct inode *dir, const unsigned char *name,
277 int namelen, int ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800279 struct buffer_head *bh;
280 struct bfs_dirent *de;
281 int block, sblock, eblock, off, pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 int i;
283
284 dprintf("name=%s, namelen=%d\n", name, namelen);
285
286 if (!namelen)
287 return -ENOENT;
288 if (namelen > BFS_NAMELEN)
289 return -ENAMETOOLONG;
290
291 sblock = BFS_I(dir)->i_sblock;
292 eblock = BFS_I(dir)->i_eblock;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800293 for (block = sblock; block <= eblock; block++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 bh = sb_bread(dir->i_sb, block);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800295 if (!bh)
Sanidhya Kashyapc3fe5872015-04-16 12:48:32 -0700296 return -EIO;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800297 for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 de = (struct bfs_dirent *)(bh->b_data + off);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 if (!de->ino) {
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800300 pos = (block - sblock) * BFS_BSIZE + off;
301 if (pos >= dir->i_size) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 dir->i_size += BFS_DIRENT_SIZE;
303 dir->i_ctime = CURRENT_TIME_SEC;
304 }
305 dir->i_mtime = CURRENT_TIME_SEC;
306 mark_inode_dirty(dir);
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700307 de->ino = cpu_to_le16((u16)ino);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800308 for (i = 0; i < BFS_NAMELEN; i++)
309 de->name[i] =
310 (i < namelen) ? name[i] : 0;
Al Viro4427f0c2009-06-08 01:15:58 -0400311 mark_buffer_dirty_inode(bh, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 brelse(bh);
313 return 0;
314 }
315 }
316 brelse(bh);
317 }
318 return -ENOSPC;
319}
320
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800321static inline int bfs_namecmp(int len, const unsigned char *name,
322 const char *buffer)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800324 if ((len < BFS_NAMELEN) && buffer[len])
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 return 0;
326 return !memcmp(name, buffer, len);
327}
328
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800329static struct buffer_head *bfs_find_entry(struct inode *dir,
330 const unsigned char *name, int namelen,
331 struct bfs_dirent **res_dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800333 unsigned long block = 0, offset = 0;
334 struct buffer_head *bh = NULL;
335 struct bfs_dirent *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
337 *res_dir = NULL;
338 if (namelen > BFS_NAMELEN)
339 return NULL;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800340
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 while (block * BFS_BSIZE + offset < dir->i_size) {
342 if (!bh) {
343 bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
344 if (!bh) {
345 block++;
346 continue;
347 }
348 }
349 de = (struct bfs_dirent *)(bh->b_data + offset);
350 offset += BFS_DIRENT_SIZE;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800351 if (le16_to_cpu(de->ino) &&
352 bfs_namecmp(namelen, name, de->name)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 *res_dir = de;
354 return bh;
355 }
356 if (offset < bh->b_size)
357 continue;
358 brelse(bh);
359 bh = NULL;
360 offset = 0;
361 block++;
362 }
363 brelse(bh);
364 return NULL;
365}