[PATCH] reiserfs: remove kmalloc wrapper
[linux-2.6.git] / fs / reiserfs / dir.c
1 /*
2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3  */
4
5 #include <linux/config.h>
6 #include <linux/string.h>
7 #include <linux/errno.h>
8 #include <linux/fs.h>
9 #include <linux/reiserfs_fs.h>
10 #include <linux/stat.h>
11 #include <linux/smp_lock.h>
12 #include <linux/buffer_head.h>
13 #include <asm/uaccess.h>
14
15 extern struct reiserfs_key MIN_KEY;
16
17 static int reiserfs_readdir(struct file *, void *, filldir_t);
18 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
19                               int datasync);
20
21 struct file_operations reiserfs_dir_operations = {
22         .read = generic_read_dir,
23         .readdir = reiserfs_readdir,
24         .fsync = reiserfs_dir_fsync,
25         .ioctl = reiserfs_ioctl,
26 };
27
28 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
29                               int datasync)
30 {
31         struct inode *inode = dentry->d_inode;
32         int err;
33         reiserfs_write_lock(inode->i_sb);
34         err = reiserfs_commit_for_inode(inode);
35         reiserfs_write_unlock(inode->i_sb);
36         if (err < 0)
37                 return err;
38         return 0;
39 }
40
41 #define store_ih(where,what) copy_item_head (where, what)
42
43 //
44 static int reiserfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
45 {
46         struct inode *inode = filp->f_dentry->d_inode;
47         struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
48         INITIALIZE_PATH(path_to_entry);
49         struct buffer_head *bh;
50         int item_num, entry_num;
51         const struct reiserfs_key *rkey;
52         struct item_head *ih, tmp_ih;
53         int search_res;
54         char *local_buf;
55         loff_t next_pos;
56         char small_buf[32];     /* avoid kmalloc if we can */
57         struct reiserfs_dir_entry de;
58         int ret = 0;
59
60         reiserfs_write_lock(inode->i_sb);
61
62         reiserfs_check_lock_depth(inode->i_sb, "readdir");
63
64         /* form key for search the next directory entry using f_pos field of
65            file structure */
66         make_cpu_key(&pos_key, inode,
67                      (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY,
68                      3);
69         next_pos = cpu_key_k_offset(&pos_key);
70
71         /*  reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */
72
73         path_to_entry.reada = PATH_READA;
74         while (1) {
75               research:
76                 /* search the directory item, containing entry with specified key */
77                 search_res =
78                     search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
79                                         &de);
80                 if (search_res == IO_ERROR) {
81                         // FIXME: we could just skip part of directory which could
82                         // not be read
83                         ret = -EIO;
84                         goto out;
85                 }
86                 entry_num = de.de_entry_num;
87                 bh = de.de_bh;
88                 item_num = de.de_item_num;
89                 ih = de.de_ih;
90                 store_ih(&tmp_ih, ih);
91
92                 /* we must have found item, that is item of this directory, */
93                 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
94                        "vs-9000: found item %h does not match to dir we readdir %K",
95                        ih, &pos_key);
96                 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
97                        "vs-9005 item_num == %d, item amount == %d",
98                        item_num, B_NR_ITEMS(bh));
99
100                 /* and entry must be not more than number of entries in the item */
101                 RFALSE(I_ENTRY_COUNT(ih) < entry_num,
102                        "vs-9010: entry number is too big %d (%d)",
103                        entry_num, I_ENTRY_COUNT(ih));
104
105                 if (search_res == POSITION_FOUND
106                     || entry_num < I_ENTRY_COUNT(ih)) {
107                         /* go through all entries in the directory item beginning from the entry, that has been found */
108                         struct reiserfs_de_head *deh =
109                             B_I_DEH(bh, ih) + entry_num;
110
111                         for (; entry_num < I_ENTRY_COUNT(ih);
112                              entry_num++, deh++) {
113                                 int d_reclen;
114                                 char *d_name;
115                                 off_t d_off;
116                                 ino_t d_ino;
117
118                                 if (!de_visible(deh))
119                                         /* it is hidden entry */
120                                         continue;
121                                 d_reclen = entry_length(bh, ih, entry_num);
122                                 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
123                                 if (!d_name[d_reclen - 1])
124                                         d_reclen = strlen(d_name);
125
126                                 if (d_reclen >
127                                     REISERFS_MAX_NAME(inode->i_sb->
128                                                       s_blocksize)) {
129                                         /* too big to send back to VFS */
130                                         continue;
131                                 }
132
133                                 /* Ignore the .reiserfs_priv entry */
134                                 if (reiserfs_xattrs(inode->i_sb) &&
135                                     !old_format_only(inode->i_sb) &&
136                                     filp->f_dentry == inode->i_sb->s_root &&
137                                     REISERFS_SB(inode->i_sb)->priv_root &&
138                                     REISERFS_SB(inode->i_sb)->priv_root->d_inode
139                                     && deh_objectid(deh) ==
140                                     le32_to_cpu(INODE_PKEY
141                                                 (REISERFS_SB(inode->i_sb)->
142                                                  priv_root->d_inode)->
143                                                 k_objectid)) {
144                                         continue;
145                                 }
146
147                                 d_off = deh_offset(deh);
148                                 filp->f_pos = d_off;
149                                 d_ino = deh_objectid(deh);
150                                 if (d_reclen <= 32) {
151                                         local_buf = small_buf;
152                                 } else {
153                                         local_buf = kmalloc(d_reclen,
154                                                             GFP_NOFS);
155                                         if (!local_buf) {
156                                                 pathrelse(&path_to_entry);
157                                                 ret = -ENOMEM;
158                                                 goto out;
159                                         }
160                                         if (item_moved(&tmp_ih, &path_to_entry)) {
161                                                 kfree(local_buf);
162                                                 goto research;
163                                         }
164                                 }
165                                 // Note, that we copy name to user space via temporary
166                                 // buffer (local_buf) because filldir will block if
167                                 // user space buffer is swapped out. At that time
168                                 // entry can move to somewhere else
169                                 memcpy(local_buf, d_name, d_reclen);
170                                 if (filldir
171                                     (dirent, local_buf, d_reclen, d_off, d_ino,
172                                      DT_UNKNOWN) < 0) {
173                                         if (local_buf != small_buf) {
174                                                 kfree(local_buf);
175                                         }
176                                         goto end;
177                                 }
178                                 if (local_buf != small_buf) {
179                                         kfree(local_buf);
180                                 }
181                                 // next entry should be looked for with such offset
182                                 next_pos = deh_offset(deh) + 1;
183
184                                 if (item_moved(&tmp_ih, &path_to_entry)) {
185                                         goto research;
186                                 }
187                         }       /* for */
188                 }
189
190                 if (item_num != B_NR_ITEMS(bh) - 1)
191                         // end of directory has been reached
192                         goto end;
193
194                 /* item we went through is last item of node. Using right
195                    delimiting key check is it directory end */
196                 rkey = get_rkey(&path_to_entry, inode->i_sb);
197                 if (!comp_le_keys(rkey, &MIN_KEY)) {
198                         /* set pos_key to key, that is the smallest and greater
199                            that key of the last entry in the item */
200                         set_cpu_key_k_offset(&pos_key, next_pos);
201                         continue;
202                 }
203
204                 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
205                         // end of directory has been reached
206                         goto end;
207                 }
208
209                 /* directory continues in the right neighboring block */
210                 set_cpu_key_k_offset(&pos_key,
211                                      le_key_k_offset(KEY_FORMAT_3_5, rkey));
212
213         }                       /* while */
214
215       end:
216         filp->f_pos = next_pos;
217         pathrelse(&path_to_entry);
218         reiserfs_check_path(&path_to_entry);
219       out:
220         reiserfs_write_unlock(inode->i_sb);
221         return ret;
222 }
223
224 /* compose directory item containing "." and ".." entries (entries are
225    not aligned to 4 byte boundary) */
226 /* the last four params are LE */
227 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
228                             __le32 par_dirid, __le32 par_objid)
229 {
230         struct reiserfs_de_head *deh;
231
232         memset(body, 0, EMPTY_DIR_SIZE_V1);
233         deh = (struct reiserfs_de_head *)body;
234
235         /* direntry header of "." */
236         put_deh_offset(&(deh[0]), DOT_OFFSET);
237         /* these two are from make_le_item_head, and are are LE */
238         deh[0].deh_dir_id = dirid;
239         deh[0].deh_objectid = objid;
240         deh[0].deh_state = 0;   /* Endian safe if 0 */
241         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
242         mark_de_visible(&(deh[0]));
243
244         /* direntry header of ".." */
245         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
246         /* key of ".." for the root directory */
247         /* these two are from the inode, and are are LE */
248         deh[1].deh_dir_id = par_dirid;
249         deh[1].deh_objectid = par_objid;
250         deh[1].deh_state = 0;   /* Endian safe if 0 */
251         put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
252         mark_de_visible(&(deh[1]));
253
254         /* copy ".." and "." */
255         memcpy(body + deh_location(&(deh[0])), ".", 1);
256         memcpy(body + deh_location(&(deh[1])), "..", 2);
257 }
258
259 /* compose directory item containing "." and ".." entries */
260 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
261                          __le32 par_dirid, __le32 par_objid)
262 {
263         struct reiserfs_de_head *deh;
264
265         memset(body, 0, EMPTY_DIR_SIZE);
266         deh = (struct reiserfs_de_head *)body;
267
268         /* direntry header of "." */
269         put_deh_offset(&(deh[0]), DOT_OFFSET);
270         /* these two are from make_le_item_head, and are are LE */
271         deh[0].deh_dir_id = dirid;
272         deh[0].deh_objectid = objid;
273         deh[0].deh_state = 0;   /* Endian safe if 0 */
274         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
275         mark_de_visible(&(deh[0]));
276
277         /* direntry header of ".." */
278         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
279         /* key of ".." for the root directory */
280         /* these two are from the inode, and are are LE */
281         deh[1].deh_dir_id = par_dirid;
282         deh[1].deh_objectid = par_objid;
283         deh[1].deh_state = 0;   /* Endian safe if 0 */
284         put_deh_location(&(deh[1]),
285                          deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
286         mark_de_visible(&(deh[1]));
287
288         /* copy ".." and "." */
289         memcpy(body + deh_location(&(deh[0])), ".", 1);
290         memcpy(body + deh_location(&(deh[1])), "..", 2);
291 }