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, int datasync) ;
19
20 struct file_operations reiserfs_dir_operations = {
21 .read = generic_read_dir,
22 .readdir = reiserfs_readdir,
23 .fsync = reiserfs_dir_fsync,
24 .ioctl = reiserfs_ioctl,
25 };
26
27 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, int datasync) {
28 struct inode *inode = dentry->d_inode;
29 int err;
30 reiserfs_write_lock(inode->i_sb);
31 err = reiserfs_commit_for_inode(inode) ;
32 reiserfs_write_unlock(inode->i_sb) ;
33 if (err < 0)
34 return err;
35 return 0;
36 }
37
38
39 #define store_ih(where,what) copy_item_head (where, what)
40
41 //
42 static int reiserfs_readdir (struct file * filp, void * dirent, filldir_t filldir)
43 {
44 struct inode *inode = filp->f_dentry->d_inode;
45 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
46 INITIALIZE_PATH (path_to_entry);
47 struct buffer_head * bh;
48 int item_num, entry_num;
49 const struct reiserfs_key * rkey;
50 struct item_head * ih, tmp_ih;
51 int search_res;
52 char * local_buf;
53 loff_t next_pos;
54 char small_buf[32] ; /* avoid kmalloc if we can */
55 struct reiserfs_dir_entry de;
56 int ret = 0;
57
58 reiserfs_write_lock(inode->i_sb);
59
60 reiserfs_check_lock_depth(inode->i_sb, "readdir") ;
61
62 /* form key for search the next directory entry using f_pos field of
63 file structure */
64 make_cpu_key (&pos_key, inode, (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET,
65 TYPE_DIRENTRY, 3);
66 next_pos = cpu_key_k_offset (&pos_key);
67
68 /* reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos);*/
69
70 path_to_entry.reada = PATH_READA;
71 while (1) {
72 research:
73 /* search the directory item, containing entry with specified key */
74 search_res = search_by_entry_key (inode->i_sb, &pos_key, &path_to_entry, &de);
75 if (search_res == IO_ERROR) {
76 // FIXME: we could just skip part of directory which could
77 // not be read
78 ret = -EIO;
79 goto out;
80 }
81 entry_num = de.de_entry_num;
82 bh = de.de_bh;
83 item_num = de.de_item_num;
84 ih = de.de_ih;
85 store_ih (&tmp_ih, ih);
86
87 /* we must have found item, that is item of this directory, */
88 RFALSE( COMP_SHORT_KEYS (&(ih->ih_key), &pos_key),
89 "vs-9000: found item %h does not match to dir we readdir %K",
90 ih, &pos_key);
91 RFALSE( item_num > B_NR_ITEMS (bh) - 1,
92 "vs-9005 item_num == %d, item amount == %d",
93 item_num, B_NR_ITEMS (bh));
94
95 /* and entry must be not more than number of entries in the item */
96 RFALSE( I_ENTRY_COUNT (ih) < entry_num,
97 "vs-9010: entry number is too big %d (%d)",
98 entry_num, I_ENTRY_COUNT (ih));
99
100 if (search_res == POSITION_FOUND || entry_num < I_ENTRY_COUNT (ih)) {
101 /* go through all entries in the directory item beginning from the entry, that has been found */
102 struct reiserfs_de_head * deh = B_I_DEH (bh, ih) + entry_num;
103
104 for (; entry_num < I_ENTRY_COUNT (ih); entry_num ++, deh ++) {
105 int d_reclen;
106 char * d_name;
107 off_t d_off;
108 ino_t d_ino;
109
110 if (!de_visible (deh))
111 /* it is hidden entry */
112 continue;
113 d_reclen = entry_length (bh, ih, entry_num);
114 d_name = B_I_DEH_ENTRY_FILE_NAME (bh, ih, deh);
115 if (!d_name[d_reclen - 1])
116 d_reclen = strlen (d_name);
117
118 if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)){
119 /* too big to send back to VFS */
120 continue ;
121 }
122
123 /* Ignore the .reiserfs_priv entry */
124 if (reiserfs_xattrs (inode->i_sb) &&
125 !old_format_only(inode->i_sb) &&
126 filp->f_dentry == inode->i_sb->s_root &&
127 REISERFS_SB(inode->i_sb)->priv_root &&
128 REISERFS_SB(inode->i_sb)->priv_root->d_inode &&
129 deh_objectid(deh) == le32_to_cpu (INODE_PKEY(REISERFS_SB(inode->i_sb)->priv_root->d_inode)->k_objectid)) {
130 continue;
131 }
132
133 d_off = deh_offset (deh);
134 filp->f_pos = d_off ;
135 d_ino = deh_objectid (deh);
136 if (d_reclen <= 32) {
137 local_buf = small_buf ;
138 } else {
139 local_buf = reiserfs_kmalloc(d_reclen, GFP_NOFS, inode->i_sb) ;
140 if (!local_buf) {
141 pathrelse (&path_to_entry);
142 ret = -ENOMEM ;
143 goto out;
144 }
145 if (item_moved (&tmp_ih, &path_to_entry)) {
146 reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
147 goto research;
148 }
149 }
150 // Note, that we copy name to user space via temporary
151 // buffer (local_buf) because filldir will block if
152 // user space buffer is swapped out. At that time
153 // entry can move to somewhere else
154 memcpy (local_buf, d_name, d_reclen);
155 if (filldir (dirent, local_buf, d_reclen, d_off, d_ino,
156 DT_UNKNOWN) < 0) {
157 if (local_buf != small_buf) {
158 reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
159 }
160 goto end;
161 }
162 if (local_buf != small_buf) {
163 reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
164 }
165
166 // next entry should be looked for with such offset
167 next_pos = deh_offset (deh) + 1;
168
169 if (item_moved (&tmp_ih, &path_to_entry)) {
170 goto research;
171 }
172 } /* for */
173 }
174
175 if (item_num != B_NR_ITEMS (bh) - 1)
176 // end of directory has been reached
177 goto end;
178
179 /* item we went through is last item of node. Using right
180 delimiting key check is it directory end */
181 rkey = get_rkey (&path_to_entry, inode->i_sb);
182 if (! comp_le_keys (rkey, &MIN_KEY)) {
183 /* set pos_key to key, that is the smallest and greater
184 that key of the last entry in the item */
185 set_cpu_key_k_offset (&pos_key, next_pos);
186 continue;
187 }
188
189 if ( COMP_SHORT_KEYS (rkey, &pos_key)) {
190 // end of directory has been reached
191 goto end;
192 }
193
194 /* directory continues in the right neighboring block */
195 set_cpu_key_k_offset (&pos_key, le_key_k_offset (KEY_FORMAT_3_5, rkey));
196
197 } /* while */
198
199
200 end:
201 filp->f_pos = next_pos;
202 pathrelse (&path_to_entry);
203 reiserfs_check_path(&path_to_entry) ;
204 out:
205 reiserfs_write_unlock(inode->i_sb);
206 return ret;
207 }
208
209 /* compose directory item containing "." and ".." entries (entries are
210 not aligned to 4 byte boundary) */
211 /* the last four params are LE */
212 void make_empty_dir_item_v1 (char * body, __u32 dirid, __u32 objid,
213 __u32 par_dirid, __u32 par_objid)
214 {
215 struct reiserfs_de_head * deh;
216
217 memset (body, 0, EMPTY_DIR_SIZE_V1);
218 deh = (struct reiserfs_de_head *)body;
219
220 /* direntry header of "." */
221 put_deh_offset( &(deh[0]), DOT_OFFSET );
222 /* these two are from make_le_item_head, and are are LE */
223 deh[0].deh_dir_id = dirid;
224 deh[0].deh_objectid = objid;
225 deh[0].deh_state = 0; /* Endian safe if 0 */
226 put_deh_location( &(deh[0]), EMPTY_DIR_SIZE_V1 - strlen( "." ));
227 mark_de_visible(&(deh[0]));
228
229 /* direntry header of ".." */
230 put_deh_offset( &(deh[1]), DOT_DOT_OFFSET);
231 /* key of ".." for the root directory */
232 /* these two are from the inode, and are are LE */
233 deh[1].deh_dir_id = par_dirid;
234 deh[1].deh_objectid = par_objid;
235 deh[1].deh_state = 0; /* Endian safe if 0 */
236 put_deh_location( &(deh[1]), deh_location( &(deh[0]) ) - strlen( ".." ) );
237 mark_de_visible(&(deh[1]));
238
239 /* copy ".." and "." */
240 memcpy (body + deh_location( &(deh[0]) ), ".", 1);
241 memcpy (body + deh_location( &(deh[1]) ), "..", 2);
242 }
243
244 /* compose directory item containing "." and ".." entries */
245 void make_empty_dir_item (char * body, __u32 dirid, __u32 objid,
246 __u32 par_dirid, __u32 par_objid)
247 {
248 struct reiserfs_de_head * deh;
249
250 memset (body, 0, EMPTY_DIR_SIZE);
251 deh = (struct reiserfs_de_head *)body;
252
253 /* direntry header of "." */
254 put_deh_offset( &(deh[0]), DOT_OFFSET );
255 /* these two are from make_le_item_head, and are are LE */
256 deh[0].deh_dir_id = dirid;
257 deh[0].deh_objectid = objid;
258 deh[0].deh_state = 0; /* Endian safe if 0 */
259 put_deh_location( &(deh[0]), EMPTY_DIR_SIZE - ROUND_UP( strlen( "." ) ) );
260 mark_de_visible(&(deh[0]));
261
262 /* direntry header of ".." */
263 put_deh_offset( &(deh[1]), DOT_DOT_OFFSET );
264 /* key of ".." for the root directory */
265 /* these two are from the inode, and are are LE */
266 deh[1].deh_dir_id = par_dirid;
267 deh[1].deh_objectid = par_objid;
268 deh[1].deh_state = 0; /* Endian safe if 0 */
269 put_deh_location( &(deh[1]), deh_location( &(deh[0])) - ROUND_UP( strlen( ".." ) ) );
270 mark_de_visible(&(deh[1]));
271
272 /* copy ".." and "." */
273 memcpy (body + deh_location( &(deh[0]) ), ".", 1);
274 memcpy (body + deh_location( &(deh[1]) ), "..", 2);
275 }
276
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