btrfs-progs: cleanup, move getop long options close to their use
[platform/upstream/btrfs-progs.git] / btrfs-map-logical.c
1 /*
2  * Copyright (C) 2009 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18
19 #define _XOPEN_SOURCE 500
20 #define _GNU_SOURCE 1
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <fcntl.h>
24 #include <unistd.h>
25 #include <getopt.h>
26 #include "kerncompat.h"
27 #include "ctree.h"
28 #include "volumes.h"
29 #include "disk-io.h"
30 #include "print-tree.h"
31 #include "transaction.h"
32 #include "list.h"
33 #include "version.h"
34 #include "utils.h"
35
36 /* we write the mirror info to stdout unless they are dumping the data
37  * to stdout
38  * */
39 static FILE *info_file;
40
41 static struct extent_buffer * debug_read_block(struct btrfs_root *root,
42                 u64 bytenr, u32 blocksize, u64 copy)
43 {
44         int ret;
45         struct extent_buffer *eb;
46         u64 length;
47         struct btrfs_multi_bio *multi = NULL;
48         struct btrfs_device *device;
49         int num_copies;
50         int mirror_num = 1;
51
52         eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
53         if (!eb)
54                 return NULL;
55
56         length = blocksize;
57         while (1) {
58                 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
59                                       eb->start, &length, &multi,
60                                       mirror_num, NULL);
61                 if (ret) {
62                         fprintf(info_file,
63                                 "Error: fails to map mirror%d logical %llu: %s\n",
64                                 mirror_num, (unsigned long long)eb->start,
65                                 strerror(-ret));
66                         free_extent_buffer(eb);
67                         return NULL;
68                 }
69                 device = multi->stripes[0].dev;
70                 eb->fd = device->fd;
71                 device->total_ios++;
72                 eb->dev_bytenr = multi->stripes[0].physical;
73
74                 fprintf(info_file, "mirror %d logical %Lu physical %Lu "
75                         "device %s\n", mirror_num, (unsigned long long)bytenr,
76                         (unsigned long long)eb->dev_bytenr, device->name);
77                 kfree(multi);
78
79                 if (!copy || mirror_num == copy) {
80                         ret = read_extent_from_disk(eb, 0, eb->len);
81                         if (ret) {
82                                 fprintf(info_file,
83                                         "Error: failed to read extent: mirror %d logical %llu: %s\n",
84                                         mirror_num, (unsigned long long)eb->start,
85                                         strerror(-ret));
86                                 free_extent_buffer(eb);
87                                 eb = NULL;
88                                 break;
89                         }
90                 }
91
92                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
93                                               eb->start, eb->len);
94                 if (num_copies == 1)
95                         break;
96
97                 mirror_num++;
98                 if (mirror_num > num_copies)
99                         break;
100         }
101         return eb;
102 }
103
104 static void print_usage(void) __attribute__((noreturn));
105 static void print_usage(void)
106 {
107         fprintf(stderr, "usage: btrfs-map-logical [options] device\n");
108         fprintf(stderr, "\t-l Logical extent to map\n");
109         fprintf(stderr, "\t-c Copy of the extent to read (usually 1 or 2)\n");
110         fprintf(stderr, "\t-o Output file to hold the extent\n");
111         fprintf(stderr, "\t-b Number of bytes to read\n");
112         exit(1);
113 }
114
115 int main(int ac, char **av)
116 {
117         struct cache_tree root_cache;
118         struct btrfs_root *root;
119         struct extent_buffer *eb;
120         char *dev;
121         char *output_file = NULL;
122         u64 logical = 0;
123         int ret = 0;
124         u64 copy = 0;
125         u64 bytes = 0;
126         int out_fd = 0;
127
128         while(1) {
129                 int c;
130                 int option_index = 0;
131                 static struct option long_options[] = {
132                         /* { "byte-count", 1, NULL, 'b' }, */
133                         { "logical", 1, NULL, 'l' },
134                         { "copy", 1, NULL, 'c' },
135                         { "output", 1, NULL, 'o' },
136                         { "bytes", 1, NULL, 'b' },
137                         { NULL, 0, NULL, 0}
138                 };
139
140                 c = getopt_long(ac, av, "l:c:o:b:", long_options,
141                                 &option_index);
142                 if (c < 0)
143                         break;
144                 switch(c) {
145                         case 'l':
146                                 logical = arg_strtou64(optarg);
147                                 break;
148                         case 'c':
149                                 copy = arg_strtou64(optarg);
150                                 break;
151                         case 'b':
152                                 bytes = arg_strtou64(optarg);
153                                 break;
154                         case 'o':
155                                 output_file = strdup(optarg);
156                                 break;
157                         default:
158                                 print_usage();
159                 }
160         }
161         set_argv0(av);
162         ac = ac - optind;
163         if (check_argc_min(ac, 1))
164                 print_usage();
165         if (logical == 0)
166                 print_usage();
167
168         dev = av[optind];
169
170         radix_tree_init();
171         cache_tree_init(&root_cache);
172
173         root = open_ctree(dev, 0, 0);
174         if (!root) {
175                 fprintf(stderr, "Open ctree failed\n");
176                 exit(1);
177         }
178
179         info_file = stdout;
180         if (output_file) {
181                 if (strcmp(output_file, "-") == 0) {
182                         out_fd = 1;
183                         info_file = stderr;
184                 } else {
185                         out_fd = open(output_file, O_RDWR | O_CREAT, 0600);
186                         if (out_fd < 0)
187                                 goto close;
188                         ret = ftruncate(out_fd, 0);
189                         if (ret) {
190                                 ret = 1;
191                                 close(out_fd);
192                                 goto close;
193                         }
194                         info_file = stdout;
195                 }
196         }
197
198         if (bytes == 0)
199                 bytes = root->sectorsize;
200
201         bytes = (bytes + root->sectorsize - 1) / root->sectorsize;
202         bytes *= root->sectorsize;
203
204         while (bytes > 0) {
205                 eb = debug_read_block(root, logical, root->sectorsize, copy);
206                 if (eb && output_file) {
207                         ret = write(out_fd, eb->data, eb->len);
208                         if (ret < 0 || ret != eb->len) {
209                                 ret = 1;
210                                 fprintf(stderr, "output file write failed\n");
211                                 goto out_close_fd;
212                         }
213                 }
214                 free_extent_buffer(eb);
215                 logical += root->sectorsize;
216                 bytes -= root->sectorsize;
217         }
218
219 out_close_fd:
220         if (output_file && out_fd != 1)
221                 close(out_fd);
222 close:
223         close_ctree(root);
224         return ret;
225 }