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Implement the ability for the test_io mechanism to abort after n reads
[tools/e2fsprogs.git] / lib / ext2fs / test_io.c
1 /*
2  * test_io.c --- This is the Test I/O interface.
3  *
4  * Copyright (C) 1996 Theodore Ts'o.
5  *
6  * %Begin-Header%
7  * This file may be redistributed under the terms of the GNU Public
8  * License.
9  * %End-Header%
10  */
11
12 #include <stdio.h>
13 #include <string.h>
14 #if HAVE_UNISTD_H
15 #include <unistd.h>
16 #endif
17 #include <fcntl.h>
18 #include <time.h>
19 #if HAVE_SYS_STAT_H
20 #include <sys/stat.h>
21 #endif
22 #if HAVE_SYS_TYPES_H
23 #include <sys/types.h>
24 #endif
25
26 #include "ext2_fs.h"
27 #include "ext2fs.h"
28
29 /*
30  * For checking structure magic numbers...
31  */
32
33 #define EXT2_CHECK_MAGIC(struct, code) \
34           if ((struct)->magic != (code)) return (code)
35   
36 struct test_private_data {
37         int     magic;
38         io_channel real;
39         int flags;
40         FILE *outfile;
41         unsigned long block;
42         int read_abort_count, write_abort_count;
43         void (*read_blk)(unsigned long block, int count, errcode_t err);
44         void (*write_blk)(unsigned long block, int count, errcode_t err);
45         void (*set_blksize)(int blksize, errcode_t err);
46         void (*write_byte)(unsigned long block, int count, errcode_t err);
47 };
48
49 static errcode_t test_open(const char *name, int flags, io_channel *channel);
50 static errcode_t test_close(io_channel channel);
51 static errcode_t test_set_blksize(io_channel channel, int blksize);
52 static errcode_t test_read_blk(io_channel channel, unsigned long block,
53                                int count, void *data);
54 static errcode_t test_write_blk(io_channel channel, unsigned long block,
55                                 int count, const void *data);
56 static errcode_t test_flush(io_channel channel);
57 static errcode_t test_write_byte(io_channel channel, unsigned long offset,
58                                  int count, const void *buf);
59
60 static struct struct_io_manager struct_test_manager = {
61         EXT2_ET_MAGIC_IO_MANAGER,
62         "Test I/O Manager",
63         test_open,
64         test_close,
65         test_set_blksize,
66         test_read_blk,
67         test_write_blk,
68         test_flush,
69         test_write_byte
70         
71 };
72
73 io_manager test_io_manager = &struct_test_manager;
74
75 /*
76  * These global variable can be set by the test program as
77  * necessary *before* calling test_open
78  */
79 io_manager test_io_backing_manager = 0;
80 void (*test_io_cb_read_blk)
81         (unsigned long block, int count, errcode_t err) = 0;
82 void (*test_io_cb_write_blk)
83         (unsigned long block, int count, errcode_t err) = 0;
84 void (*test_io_cb_set_blksize)
85         (int blksize, errcode_t err) = 0;
86 void (*test_io_cb_write_byte)
87         (unsigned long block, int count, errcode_t err) = 0;
88
89 /*
90  * Test flags
91  */
92 #define TEST_FLAG_READ                  0x01
93 #define TEST_FLAG_WRITE                 0x02
94 #define TEST_FLAG_SET_BLKSIZE           0x04
95 #define TEST_FLAG_FLUSH                 0x08
96 #define TEST_FLAG_DUMP                  0x10
97
98 static void test_dump_block(io_channel channel,
99                             struct test_private_data *data,
100                             unsigned long block, const void *buf)
101 {
102         const unsigned char *cp;
103         FILE *f = data->outfile;
104         int     i;
105         unsigned long   cksum = 0;
106
107         for (i=0, cp = buf; i < channel->block_size; i++, cp++) {
108                 cksum += *cp;
109         }
110         fprintf(f, "Contents of block %lu, checksum %08lu: \n", block, cksum);
111         for (i=0, cp = buf; i < channel->block_size; i++, cp++) {
112                 if ((i % 16) == 0)
113                         fprintf(f, "%04x: ", i);
114                 fprintf(f, "%02x%c", *cp, ((i % 16) == 15) ? '\n' : ' ');
115         }
116 }
117
118 static void test_abort(io_channel channel, unsigned long block)
119 {
120         struct test_private_data *data;
121         FILE *f;
122
123         data = (struct test_private_data *) channel->private_data;
124         f = data->outfile;
125         test_flush(channel);
126
127         fprintf(f, "Aborting due to I/O to block %lu\n", block);
128         fflush(f);
129         abort();
130 }
131
132 static errcode_t test_open(const char *name, int flags, io_channel *channel)
133 {
134         io_channel      io = NULL;
135         struct test_private_data *data = NULL;
136         errcode_t       retval;
137         char            *value;
138
139         if (name == 0)
140                 return EXT2_ET_BAD_DEVICE_NAME;
141         retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
142         if (retval)
143                 return retval;
144         memset(io, 0, sizeof(struct struct_io_channel));
145         io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
146         retval = ext2fs_get_mem(sizeof(struct test_private_data), &data);
147         if (retval) {
148                 retval = EXT2_ET_NO_MEMORY;
149                 goto cleanup;
150         }
151         io->manager = test_io_manager;
152         retval = ext2fs_get_mem(strlen(name)+1, &io->name);
153         if (retval)
154                 goto cleanup;
155
156         strcpy(io->name, name);
157         io->private_data = data;
158         io->block_size = 1024;
159         io->read_error = 0;
160         io->write_error = 0;
161         io->refcount = 1;
162
163         memset(data, 0, sizeof(struct test_private_data));
164         data->magic = EXT2_ET_MAGIC_TEST_IO_CHANNEL;
165         if (test_io_backing_manager) {
166                 retval = test_io_backing_manager->open(name, flags,
167                                                        &data->real);
168                 if (retval)
169                         goto cleanup;
170         } else
171                 data->real = 0;
172         data->read_blk =        test_io_cb_read_blk;
173         data->write_blk =       test_io_cb_write_blk;
174         data->set_blksize =     test_io_cb_set_blksize;
175         data->write_byte =      test_io_cb_write_byte;
176
177         data->outfile = NULL;
178         if ((value = getenv("TEST_IO_LOGFILE")) != NULL)
179                 data->outfile = fopen(value, "w");
180         if (!data->outfile)
181                 data->outfile = stderr;
182
183         data->flags = 0;
184         if ((value = getenv("TEST_IO_FLAGS")) != NULL)
185                 data->flags = strtoul(value, NULL, 0);
186         
187         data->block = 0;
188         if ((value = getenv("TEST_IO_BLOCK")) != NULL)
189                 data->block = strtoul(value, NULL, 0);
190
191         data->read_abort_count = 0;
192         if ((value = getenv("TEST_IO_READ_ABORT")) != NULL)
193                 data->read_abort_count = strtoul(value, NULL, 0);
194
195         data->write_abort_count = 0;
196         if ((value = getenv("TEST_IO_WRITE_ABORT")) != NULL)
197                 data->write_abort_count = strtoul(value, NULL, 0);
198         
199         *channel = io;
200         return 0;
201
202 cleanup:
203         if (io)
204                 ext2fs_free_mem(&io);
205         if (data)
206                 ext2fs_free_mem(&data);
207         return retval;
208 }
209
210 static errcode_t test_close(io_channel channel)
211 {
212         struct test_private_data *data;
213         errcode_t       retval = 0;
214
215         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
216         data = (struct test_private_data *) channel->private_data;
217         EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);
218
219         if (--channel->refcount > 0)
220                 return 0;
221         
222         if (data->real)
223                 retval = io_channel_close(data->real);
224
225         if (data->outfile && data->outfile != stderr)
226                 fclose(data->outfile);
227         
228         ext2fs_free_mem(&channel->private_data);
229         if (channel->name)
230                 ext2fs_free_mem(&channel->name);
231         ext2fs_free_mem(&channel);
232         return retval;
233 }
234
235 static errcode_t test_set_blksize(io_channel channel, int blksize)
236 {
237         struct test_private_data *data;
238         errcode_t       retval = 0;
239
240         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
241         data = (struct test_private_data *) channel->private_data;
242         EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);
243
244         if (data->real)
245                 retval = io_channel_set_blksize(data->real, blksize);
246         if (data->set_blksize)
247                 data->set_blksize(blksize, retval);
248         if (data->flags & TEST_FLAG_SET_BLKSIZE)
249                 fprintf(data->outfile,
250                         "Test_io: set_blksize(%d) returned %s\n",
251                         blksize, retval ? error_message(retval) : "OK");
252         channel->block_size = blksize;
253         return retval;
254 }
255
256
257 static errcode_t test_read_blk(io_channel channel, unsigned long block,
258                                int count, void *buf)
259 {
260         struct test_private_data *data;
261         errcode_t       retval = 0;
262
263         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
264         data = (struct test_private_data *) channel->private_data;
265         EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);
266
267         if (data->real)
268                 retval = io_channel_read_blk(data->real, block, count, buf);
269         if (data->read_blk)
270                 data->read_blk(block, count, retval);
271         if (data->flags & TEST_FLAG_READ)
272                 fprintf(data->outfile,
273                         "Test_io: read_blk(%lu, %d) returned %s\n",
274                         block, count, retval ? error_message(retval) : "OK");
275         if (data->block && data->block == block) {
276                 if (data->flags & TEST_FLAG_DUMP)
277                         test_dump_block(channel, data, block, buf);
278                 if (--data->read_abort_count == 0)
279                         test_abort(channel, block);
280         } 
281         return retval;
282 }
283
284 static errcode_t test_write_blk(io_channel channel, unsigned long block,
285                                int count, const void *buf)
286 {
287         struct test_private_data *data;
288         errcode_t       retval = 0;
289
290         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
291         data = (struct test_private_data *) channel->private_data;
292         EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);
293
294         if (data->real)
295                 retval = io_channel_write_blk(data->real, block, count, buf);
296         if (data->write_blk)
297                 data->write_blk(block, count, retval);
298         if (data->flags & TEST_FLAG_WRITE)
299                 fprintf(data->outfile,
300                         "Test_io: write_blk(%lu, %d) returned %s\n",
301                         block, count, retval ? error_message(retval) : "OK");
302         if (data->block && data->block == block) {
303                 if (data->flags & TEST_FLAG_DUMP)
304                         test_dump_block(channel, data, block, buf);
305                 if (--data->write_abort_count == 0)
306                         test_abort(channel, block);
307         }
308         return retval;
309 }
310
311 static errcode_t test_write_byte(io_channel channel, unsigned long offset,
312                                int count, const void *buf)
313 {
314         struct test_private_data *data;
315         errcode_t       retval = 0;
316
317         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
318         data = (struct test_private_data *) channel->private_data;
319         EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);
320
321         if (data->real && data->real->manager->write_byte)
322                 retval = io_channel_write_byte(data->real, offset, count, buf);
323         if (data->write_byte)
324                 data->write_byte(offset, count, retval);
325         if (data->flags & TEST_FLAG_WRITE)
326                 fprintf(data->outfile,
327                         "Test_io: write_byte(%lu, %d) returned %s\n",
328                         offset, count, retval ? error_message(retval) : "OK");
329         return retval;
330 }
331
332 /*
333  * Flush data buffers to disk.
334  */
335 static errcode_t test_flush(io_channel channel)
336 {
337         struct test_private_data *data;
338         errcode_t       retval = 0;
339         
340         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
341         data = (struct test_private_data *) channel->private_data;
342         EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);
343
344         if (data->real)
345                 retval = io_channel_flush(data->real);
346         
347         if (data->flags & TEST_FLAG_FLUSH)
348                 fprintf(data->outfile, "Test_io: flush() returned %s\n",
349                         retval ? error_message(retval) : "OK");
350         
351         return retval;
352 }
353