~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/bfs/dir.c

Version: ~ [ linux-5.5-rc7 ] ~ [ linux-5.4.13 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.97 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.166 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.210 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.210 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.81 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  *      fs/bfs/dir.c
  3  *      BFS directory operations.
  4  *      Copyright (C) 1999,2000  Tigran Aivazian <tigran@veritas.com>
  5  *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005
  6  */
  7 
  8 #include <linux/time.h>
  9 #include <linux/string.h>
 10 #include <linux/fs.h>
 11 #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 
 23 static int bfs_add_entry(struct inode *dir, const unsigned char *name,
 24                                                 int namelen, int ino);
 25 static struct buffer_head *bfs_find_entry(struct inode *dir,
 26                                 const unsigned char *name, int namelen,
 27                                 struct bfs_dirent **res_dir);
 28 
 29 static int bfs_readdir(struct file *f, struct dir_context *ctx)
 30 {
 31         struct inode *dir = file_inode(f);
 32         struct buffer_head *bh;
 33         struct bfs_dirent *de;
 34         unsigned int offset;
 35         int block;
 36 
 37         if (ctx->pos & (BFS_DIRENT_SIZE - 1)) {
 38                 printf("Bad f_pos=%08lx for %s:%08lx\n",
 39                                         (unsigned long)ctx->pos,
 40                                         dir->i_sb->s_id, dir->i_ino);
 41                 return -EINVAL;
 42         }
 43 
 44         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);
 47                 bh = sb_bread(dir->i_sb, block);
 48                 if (!bh) {
 49                         ctx->pos += BFS_BSIZE - offset;
 50                         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);
 56                                 if (!dir_emit(ctx, de->name, size,
 57                                                 le16_to_cpu(de->ino),
 58                                                 DT_UNKNOWN)) {
 59                                         brelse(bh);
 60                                         return 0;
 61                                 }
 62                         }
 63                         offset += BFS_DIRENT_SIZE;
 64                         ctx->pos += BFS_DIRENT_SIZE;
 65                 } while ((offset < BFS_BSIZE) && (ctx->pos < dir->i_size));
 66                 brelse(bh);
 67         }
 68         return 0;
 69 }
 70 
 71 const struct file_operations bfs_dir_operations = {
 72         .read           = generic_read_dir,
 73         .iterate_shared = bfs_readdir,
 74         .fsync          = generic_file_fsync,
 75         .llseek         = generic_file_llseek,
 76 };
 77 
 78 static int bfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 79                                                 bool excl)
 80 {
 81         int err;
 82         struct inode *inode;
 83         struct super_block *s = dir->i_sb;
 84         struct bfs_sb_info *info = BFS_SB(s);
 85         unsigned long ino;
 86 
 87         inode = new_inode(s);
 88         if (!inode)
 89                 return -ENOMEM;
 90         mutex_lock(&info->bfs_lock);
 91         ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
 92         if (ino > info->si_lasti) {
 93                 mutex_unlock(&info->bfs_lock);
 94                 iput(inode);
 95                 return -ENOSPC;
 96         }
 97         set_bit(ino, info->si_imap);
 98         info->si_freei--;
 99         inode_init_owner(inode, dir, mode);
100         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
101         inode->i_blocks = 0;
102         inode->i_op = &bfs_file_inops;
103         inode->i_fop = &bfs_file_operations;
104         inode->i_mapping->a_ops = &bfs_aops;
105         inode->i_ino = ino;
106         BFS_I(inode)->i_dsk_ino = ino;
107         BFS_I(inode)->i_sblock = 0;
108         BFS_I(inode)->i_eblock = 0;
109         insert_inode_hash(inode);
110         mark_inode_dirty(inode);
111         bfs_dump_imap("create", s);
112 
113         err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
114                                                         inode->i_ino);
115         if (err) {
116                 inode_dec_link_count(inode);
117                 mutex_unlock(&info->bfs_lock);
118                 iput(inode);
119                 return err;
120         }
121         mutex_unlock(&info->bfs_lock);
122         d_instantiate(dentry, inode);
123         return 0;
124 }
125 
126 static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
127                                                 unsigned int flags)
128 {
129         struct inode *inode = NULL;
130         struct buffer_head *bh;
131         struct bfs_dirent *de;
132         struct bfs_sb_info *info = BFS_SB(dir->i_sb);
133 
134         if (dentry->d_name.len > BFS_NAMELEN)
135                 return ERR_PTR(-ENAMETOOLONG);
136 
137         mutex_lock(&info->bfs_lock);
138         bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
139         if (bh) {
140                 unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
141                 brelse(bh);
142                 inode = bfs_iget(dir->i_sb, ino);
143                 if (IS_ERR(inode)) {
144                         mutex_unlock(&info->bfs_lock);
145                         return ERR_CAST(inode);
146                 }
147         }
148         mutex_unlock(&info->bfs_lock);
149         d_add(dentry, inode);
150         return NULL;
151 }
152 
153 static int bfs_link(struct dentry *old, struct inode *dir,
154                                                 struct dentry *new)
155 {
156         struct inode *inode = d_inode(old);
157         struct bfs_sb_info *info = BFS_SB(inode->i_sb);
158         int err;
159 
160         mutex_lock(&info->bfs_lock);
161         err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
162                                                         inode->i_ino);
163         if (err) {
164                 mutex_unlock(&info->bfs_lock);
165                 return err;
166         }
167         inc_nlink(inode);
168         inode->i_ctime = current_time(inode);
169         mark_inode_dirty(inode);
170         ihold(inode);
171         d_instantiate(new, inode);
172         mutex_unlock(&info->bfs_lock);
173         return 0;
174 }
175 
176 static int bfs_unlink(struct inode *dir, struct dentry *dentry)
177 {
178         int error = -ENOENT;
179         struct inode *inode = d_inode(dentry);
180         struct buffer_head *bh;
181         struct bfs_dirent *de;
182         struct bfs_sb_info *info = BFS_SB(inode->i_sb);
183 
184         mutex_lock(&info->bfs_lock);
185         bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
186         if (!bh || (le16_to_cpu(de->ino) != inode->i_ino))
187                 goto out_brelse;
188 
189         if (!inode->i_nlink) {
190                 printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
191                                         inode->i_sb->s_id, inode->i_ino,
192                                         inode->i_nlink);
193                 set_nlink(inode, 1);
194         }
195         de->ino = 0;
196         mark_buffer_dirty_inode(bh, dir);
197         dir->i_ctime = dir->i_mtime = current_time(dir);
198         mark_inode_dirty(dir);
199         inode->i_ctime = dir->i_ctime;
200         inode_dec_link_count(inode);
201         error = 0;
202 
203 out_brelse:
204         brelse(bh);
205         mutex_unlock(&info->bfs_lock);
206         return error;
207 }
208 
209 static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
210                       struct inode *new_dir, struct dentry *new_dentry,
211                       unsigned int flags)
212 {
213         struct inode *old_inode, *new_inode;
214         struct buffer_head *old_bh, *new_bh;
215         struct bfs_dirent *old_de, *new_de;
216         struct bfs_sb_info *info;
217         int error = -ENOENT;
218 
219         if (flags & ~RENAME_NOREPLACE)
220                 return -EINVAL;
221 
222         old_bh = new_bh = NULL;
223         old_inode = d_inode(old_dentry);
224         if (S_ISDIR(old_inode->i_mode))
225                 return -EINVAL;
226 
227         info = BFS_SB(old_inode->i_sb);
228 
229         mutex_lock(&info->bfs_lock);
230         old_bh = bfs_find_entry(old_dir, 
231                                 old_dentry->d_name.name, 
232                                 old_dentry->d_name.len, &old_de);
233 
234         if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino))
235                 goto end_rename;
236 
237         error = -EPERM;
238         new_inode = d_inode(new_dentry);
239         new_bh = bfs_find_entry(new_dir, 
240                                 new_dentry->d_name.name, 
241                                 new_dentry->d_name.len, &new_de);
242 
243         if (new_bh && !new_inode) {
244                 brelse(new_bh);
245                 new_bh = NULL;
246         }
247         if (!new_bh) {
248                 error = bfs_add_entry(new_dir, 
249                                         new_dentry->d_name.name,
250                                         new_dentry->d_name.len,
251                                         old_inode->i_ino);
252                 if (error)
253                         goto end_rename;
254         }
255         old_de->ino = 0;
256         old_dir->i_ctime = old_dir->i_mtime = current_time(old_dir);
257         mark_inode_dirty(old_dir);
258         if (new_inode) {
259                 new_inode->i_ctime = current_time(new_inode);
260                 inode_dec_link_count(new_inode);
261         }
262         mark_buffer_dirty_inode(old_bh, old_dir);
263         error = 0;
264 
265 end_rename:
266         mutex_unlock(&info->bfs_lock);
267         brelse(old_bh);
268         brelse(new_bh);
269         return error;
270 }
271 
272 const struct inode_operations bfs_dir_inops = {
273         .create                 = bfs_create,
274         .lookup                 = bfs_lookup,
275         .link                   = bfs_link,
276         .unlink                 = bfs_unlink,
277         .rename                 = bfs_rename,
278 };
279 
280 static int bfs_add_entry(struct inode *dir, const unsigned char *name,
281                                                         int namelen, int ino)
282 {
283         struct buffer_head *bh;
284         struct bfs_dirent *de;
285         int block, sblock, eblock, off, pos;
286         int i;
287 
288         dprintf("name=%s, namelen=%d\n", name, namelen);
289 
290         if (!namelen)
291                 return -ENOENT;
292         if (namelen > BFS_NAMELEN)
293                 return -ENAMETOOLONG;
294 
295         sblock = BFS_I(dir)->i_sblock;
296         eblock = BFS_I(dir)->i_eblock;
297         for (block = sblock; block <= eblock; block++) {
298                 bh = sb_bread(dir->i_sb, block);
299                 if (!bh)
300                         return -EIO;
301                 for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
302                         de = (struct bfs_dirent *)(bh->b_data + off);
303                         if (!de->ino) {
304                                 pos = (block - sblock) * BFS_BSIZE + off;
305                                 if (pos >= dir->i_size) {
306                                         dir->i_size += BFS_DIRENT_SIZE;
307                                         dir->i_ctime = current_time(dir);
308                                 }
309                                 dir->i_mtime = current_time(dir);
310                                 mark_inode_dirty(dir);
311                                 de->ino = cpu_to_le16((u16)ino);
312                                 for (i = 0; i < BFS_NAMELEN; i++)
313                                         de->name[i] =
314                                                 (i < namelen) ? name[i] : 0;
315                                 mark_buffer_dirty_inode(bh, dir);
316                                 brelse(bh);
317                                 return 0;
318                         }
319                 }
320                 brelse(bh);
321         }
322         return -ENOSPC;
323 }
324 
325 static inline int bfs_namecmp(int len, const unsigned char *name,
326                                                         const char *buffer)
327 {
328         if ((len < BFS_NAMELEN) && buffer[len])
329                 return 0;
330         return !memcmp(name, buffer, len);
331 }
332 
333 static struct buffer_head *bfs_find_entry(struct inode *dir,
334                         const unsigned char *name, int namelen,
335                         struct bfs_dirent **res_dir)
336 {
337         unsigned long block = 0, offset = 0;
338         struct buffer_head *bh = NULL;
339         struct bfs_dirent *de;
340 
341         *res_dir = NULL;
342         if (namelen > BFS_NAMELEN)
343                 return NULL;
344 
345         while (block * BFS_BSIZE + offset < dir->i_size) {
346                 if (!bh) {
347                         bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
348                         if (!bh) {
349                                 block++;
350                                 continue;
351                         }
352                 }
353                 de = (struct bfs_dirent *)(bh->b_data + offset);
354                 offset += BFS_DIRENT_SIZE;
355                 if (le16_to_cpu(de->ino) &&
356                                 bfs_namecmp(namelen, name, de->name)) {
357                         *res_dir = de;
358                         return bh;
359                 }
360                 if (offset < bh->b_size)
361                         continue;
362                 brelse(bh);
363                 bh = NULL;
364                 offset = 0;
365                 block++;
366         }
367         brelse(bh);
368         return NULL;
369 }
370 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp