1 /* vi: set sw=4 ts=4: */
2 /*
3  * Mini df implementation for busybox
4  *
5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6  * based on original code by (I think) Bruce Perens <bruce@pixar.com>.
7  *
8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
9  */
10 /* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
11  *
12  * Size reduction.  Removed floating point dependency.  Added error checking
13  * on output.  Output stats on 0-sized filesystems if specifically listed on
14  * the command line.  Properly round *-blocks, Used, and Available quantities.
15  *
16  * Aug 28, 2008      Bernhard Reutner-Fischer
17  *
18  * Implement -P and -B; better coreutils compat; cleanup
19  */
20 //config:config DF
21 //config:	bool "df (6.8 kb)"
22 //config:	default y
23 //config:	help
24 //config:	df reports the amount of disk space used and available
25 //config:	on filesystems.
26 //config:
27 //config:config FEATURE_DF_FANCY
28 //config:	bool "Enable -a, -i, -B"
29 //config:	default y
30 //config:	depends on DF
31 //config:	help
32 //config:	-a Show all filesystems
33 //config:	-i Inodes
34 //config:	-B <SIZE> Blocksize
35 //config:
36 //config:config FEATURE_SKIP_ROOTFS
37 //config:	bool "Skip rootfs in mount table"
38 //config:	default y
39 //config:	depends on DF
40 //config:	help
41 //config:	Ignore rootfs entry in mount table.
42 //config:
43 //config:	In Linux, kernel has a special filesystem, rootfs, which is initially
44 //config:	mounted on /. It contains initramfs data, if kernel is configured
45 //config:	to have one. Usually, another file system is mounted over / early
46 //config:	in boot process, and therefore most tools which manipulate
47 //config:	mount table, such as df, will skip rootfs entry.
48 //config:
49 //config:	However, some systems do not mount anything on /.
50 //config:	If you need to configure busybox for one of these systems,
51 //config:	you may find it useful to turn this option off to make df show
52 //config:	initramfs statistics.
53 //config:
54 //config:	Otherwise, choose Y.
55 
56 //applet:IF_DF(APPLET_NOEXEC(df, df, BB_DIR_BIN, BB_SUID_DROP, df))
57 
58 //kbuild:lib-$(CONFIG_DF) += df.o
59 
60 /* BB_AUDIT SUSv3 _NOT_ compliant -- option -t missing. */
61 /* http://www.opengroup.org/onlinepubs/007904975/utilities/df.html */
62 
63 //usage:#define df_trivial_usage
64 //usage:	"[-Pk"
65 //usage:	IF_FEATURE_HUMAN_READABLE("mh")
66 //usage:	"T"
67 //usage:	IF_FEATURE_DF_FANCY("ai] [-B SIZE")
68 //usage:	"] [-t TYPE] [FILESYSTEM]..."
69 //usage:#define df_full_usage "\n\n"
70 //usage:       "Print filesystem usage statistics\n"
71 //usage:     "\n	-P	POSIX output format"
72 //usage:     "\n	-k	1024-byte blocks (default)"
73 //usage:	IF_FEATURE_HUMAN_READABLE(
74 //usage:     "\n	-m	1M-byte blocks"
75 //usage:     "\n	-h	Human readable (e.g. 1K 243M 2G)"
76 //usage:	)
77 //usage:     "\n	-T	Print filesystem type"
78 //usage:     "\n	-t TYPE	Print only mounts of this type"
79 //usage:	IF_FEATURE_DF_FANCY(
80 //usage:     "\n	-a	Show all filesystems"
81 //usage:     "\n	-i	Inodes"
82 //usage:     "\n	-B SIZE	Blocksize"
83 //usage:	)
84 //usage:
85 //usage:#define df_example_usage
86 //usage:       "$ df\n"
87 //usage:       "Filesystem           1K-blocks      Used Available Use% Mounted on\n"
88 //usage:       "/dev/sda3              8690864   8553540    137324  98% /\n"
89 //usage:       "/dev/sda1                64216     36364     27852  57% /boot\n"
90 //usage:       "$ df /dev/sda3\n"
91 //usage:       "Filesystem           1K-blocks      Used Available Use% Mounted on\n"
92 //usage:       "/dev/sda3              8690864   8553540    137324  98% /\n"
93 //usage:       "$ POSIXLY_CORRECT=sure df /dev/sda3\n"
94 //usage:       "Filesystem         512B-blocks      Used Available Use% Mounted on\n"
95 //usage:       "/dev/sda3             17381728  17107080    274648  98% /\n"
96 //usage:       "$ POSIXLY_CORRECT=yep df -P /dev/sda3\n"
97 //usage:       "Filesystem          512-blocks      Used Available Capacity Mounted on\n"
98 //usage:       "/dev/sda3             17381728  17107080    274648      98% /\n"
99 
100 #include <mntent.h>
101 #include <sys/statvfs.h>
102 #include "libbb.h"
103 #include "unicode.h"
104 
105 #if !ENABLE_FEATURE_HUMAN_READABLE
kscale(unsigned long b,unsigned long bs)106 static unsigned long kscale(unsigned long b, unsigned long bs)
107 {
108 	return (b * (unsigned long long) bs + 1024/2) / 1024;
109 }
110 #endif
111 
112 int df_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
df_main(int argc UNUSED_PARAM,char ** argv)113 int df_main(int argc UNUSED_PARAM, char **argv)
114 {
115 	unsigned long df_disp_hr = 1024;
116 	int status = EXIT_SUCCESS;
117 	unsigned opt;
118 	FILE *mount_table;
119 	struct mntent *mount_entry;
120 	struct statvfs s;
121 	enum {
122 		OPT_KILO     = (1 << 0),
123 		OPT_POSIX    = (1 << 1),
124 		OPT_FSTYPE   = (1 << 2),
125 		OPT_t        = (1 << 3),
126 		OPT_ALL      = (1 << 4) * ENABLE_FEATURE_DF_FANCY,
127 		OPT_INODE    = (1 << 5) * ENABLE_FEATURE_DF_FANCY,
128 		OPT_BSIZE    = (1 << 6) * ENABLE_FEATURE_DF_FANCY,
129 		OPT_HUMAN    = (1 << (4 + 3*ENABLE_FEATURE_DF_FANCY)) * ENABLE_FEATURE_HUMAN_READABLE,
130 		OPT_HUMANDEC = (1 << (5 + 3*ENABLE_FEATURE_DF_FANCY)) * ENABLE_FEATURE_HUMAN_READABLE,
131 		OPT_MEGA     = (1 << (6 + 3*ENABLE_FEATURE_DF_FANCY)) * ENABLE_FEATURE_HUMAN_READABLE,
132 	};
133 	const char *disp_units_hdr = NULL;
134 	char *chp, *opt_t;
135 
136 	init_unicode();
137 
138 	/* From the manpage of df from coreutils-6.10:
139 	 * Disk space is shown in 1K blocks by default, unless the environment
140 	 * variable POSIXLY_CORRECT is set, in which case 512-byte blocks are used.
141 	 */
142 	if (getenv("POSIXLY_CORRECT")) /* TODO - a new libbb function? */
143 		df_disp_hr = 512;
144 
145 	opt = getopt32(argv, "^"
146 			"kPTt:"
147 			IF_FEATURE_DF_FANCY("aiB:")
148 			IF_FEATURE_HUMAN_READABLE("hHm")
149 			"\0"
150 #if ENABLE_FEATURE_HUMAN_READABLE && ENABLE_FEATURE_DF_FANCY
151 			"k-mB:m-Bk:B-km"
152 #elif ENABLE_FEATURE_HUMAN_READABLE
153 			"k-m:m-k"
154 #endif
155 			, &opt_t
156 			IF_FEATURE_DF_FANCY(, &chp)
157 	);
158 	if (opt & OPT_MEGA)
159 		df_disp_hr = 1024*1024;
160 
161 	if (opt & OPT_BSIZE) {
162 		/* GNU coreutils 8.25 accepts "-BMiB" form too */
163 		int i;
164 		for (i = 0; kmg_i_suffixes[i].suffix[0]; i++) {
165 			if (strcmp(kmg_i_suffixes[i].suffix, chp) == 0) {
166 				df_disp_hr = kmg_i_suffixes[i].mult;
167 				goto got_it;
168 			}
169 		}
170 		/* Range used to disallow 0 */
171 		df_disp_hr = xatoul_range_sfx(chp, 1, ULONG_MAX, kmg_i_suffixes);
172  got_it: ;
173 	}
174 
175 	if (opt & (OPT_HUMAN|OPT_HUMANDEC)) {
176 		df_disp_hr = 0;
177 //TODO: need to add support in make_human_readable_str() for "decimal human readable"
178 		//if (opt & OPT_HUMANDEC)
179 		//	df_disp_hr--;
180 		disp_units_hdr = "     Size";
181 	}
182 	if (opt & OPT_INODE)
183 		disp_units_hdr = "   Inodes";
184 
185 	if (disp_units_hdr == NULL) {
186 #if ENABLE_FEATURE_HUMAN_READABLE
187 		disp_units_hdr = xasprintf("%s-blocks",
188 			/* print df_disp_hr, show no fractionals,
189 			 * use suffixes if OPT_POSIX is set in opt */
190 			make_human_readable_str(df_disp_hr, 0, !!(opt & OPT_POSIX))
191 		);
192 #else
193 		disp_units_hdr = xasprintf("%lu-blocks", df_disp_hr);
194 #endif
195 	}
196 
197 	printf("Filesystem           %s%-15sUsed Available %s Mounted on\n",
198 			(opt & OPT_FSTYPE) ? "Type       " : "",
199 			disp_units_hdr,
200 			(opt & OPT_POSIX) ? "Capacity" : "Use%");
201 
202 	mount_table = NULL;
203 	argv += optind;
204 	if (!argv[0]) {
205 		mount_table = setmntent(bb_path_mtab_file, "r");
206 		if (!mount_table)
207 			bb_simple_perror_msg_and_die(bb_path_mtab_file);
208 	}
209 
210 	while (1) {
211 		const char *device;
212 		const char *mount_point;
213 		const char *fs_type;
214 
215 		if (mount_table) {
216 			mount_entry = getmntent(mount_table);
217 			if (!mount_entry) {
218 				endmntent(mount_table);
219 				break;
220 			}
221 		} else {
222 			mount_point = *argv++;
223 			if (!mount_point)
224 				break;
225 			mount_entry = find_mount_point(mount_point, 1);
226 			if (!mount_entry) {
227 				bb_error_msg("%s: can't find mount point", mount_point);
228  set_error:
229 				status = EXIT_FAILURE;
230 				continue;
231 			}
232 		}
233 
234 		device = mount_entry->mnt_fsname;
235 
236 		/* GNU coreutils 6.10 skips certain mounts, try to be compatible */
237 		if (ENABLE_FEATURE_SKIP_ROOTFS && strcmp(device, "rootfs") == 0)
238 			continue;
239 
240 		mount_point = mount_entry->mnt_dir;
241 		fs_type = mount_entry->mnt_type;
242 
243 		if (opt & OPT_t) {
244 			if (strcmp(fs_type, opt_t) != 0)
245 				continue;
246 		}
247 
248 		if (statvfs(mount_point, &s) != 0) {
249 			bb_simple_perror_msg(mount_point);
250 			goto set_error;
251 		}
252 		/* Some uclibc versions were seen to lose f_frsize
253 		 * (kernel does return it, but then uclibc does not copy it)
254 		 */
255 		if (s.f_frsize == 0)
256 			s.f_frsize = s.f_bsize;
257 
258 		if ((s.f_blocks > 0) || !mount_table || (opt & OPT_ALL)) {
259 			unsigned long long blocks_used;
260 			unsigned long long blocks_total;
261 			unsigned blocks_percent_used;
262 
263 			if (opt & OPT_INODE) {
264 				s.f_blocks = s.f_files;
265 				s.f_bavail = s.f_bfree = s.f_ffree;
266 				s.f_frsize = 1;
267 				if (df_disp_hr)
268 					df_disp_hr = 1;
269 			}
270 			blocks_used = s.f_blocks - s.f_bfree;
271 			blocks_total = blocks_used + s.f_bavail;
272 			blocks_percent_used = blocks_total; /* 0% if blocks_total == 0, else... */
273 			if (blocks_total != 0) {
274 				/* Downscale sizes for narrower division */
275 				unsigned u;
276 				while (blocks_total >= INT_MAX / 101) {
277 					blocks_total >>= 1;
278 					blocks_used >>= 1;
279 				}
280 				u = (unsigned)blocks_used * 100u + (unsigned)blocks_total / 2;
281 				blocks_percent_used = u / (unsigned)blocks_total;
282 			}
283 
284 #ifdef WHY_WE_DO_IT_FOR_DEV_ROOT_ONLY
285 			if (strcmp(device, "/dev/root") == 0) {
286 				/* Adjusts device to be the real root device,
287 				 * or leaves device alone if it can't find it */
288 				device = find_block_device("/");
289 				if (!device) {
290 					goto set_error;
291 				}
292 			}
293 #endif
294 
295 #if ENABLE_UNICODE_SUPPORT
296 			{
297 				uni_stat_t uni_stat;
298 				char *uni_dev = unicode_conv_to_printable(&uni_stat, device);
299 				if (uni_stat.unicode_width > 20 && !(opt & OPT_POSIX)) {
300 					printf("%s\n%20s", uni_dev, "");
301 				} else {
302 					printf("%s%*s", uni_dev, 20 - (int)uni_stat.unicode_width, "");
303 				}
304 				free(uni_dev);
305 				if (opt & OPT_FSTYPE) {
306 					char *uni_type = unicode_conv_to_printable(&uni_stat, fs_type);
307 					if (uni_stat.unicode_width > 10 && !(opt & OPT_POSIX))
308 						printf(" %s\n%31s", uni_type, "");
309 					else
310 						printf(" %s%*s", uni_type, 10 - (int)uni_stat.unicode_width, "");
311 					free(uni_type);
312 				}
313 			}
314 #else
315 			if (printf("\n%-20s" + 1, device) > 20 && !(opt & OPT_POSIX))
316 				printf("\n%-20s", "");
317 			if (opt & OPT_FSTYPE) {
318 				if (printf(" %-10s", fs_type) > 11 && !(opt & OPT_POSIX))
319 					printf("\n%-30s", "");
320 			}
321 #endif
322 
323 #if ENABLE_FEATURE_HUMAN_READABLE
324 			printf(" %9s ",
325 				/* f_blocks x f_frsize / df_disp_hr, show one fractional,
326 				 * use suffixes if df_disp_hr == 0 */
327 				make_human_readable_str(s.f_blocks, s.f_frsize, df_disp_hr));
328 
329 			printf(" %9s " + 1,
330 				/* EXPR x f_frsize / df_disp_hr, show one fractional,
331 				 * use suffixes if df_disp_hr == 0 */
332 				make_human_readable_str((s.f_blocks - s.f_bfree),
333 						s.f_frsize, df_disp_hr));
334 
335 			printf("%9s %3u%% %s\n",
336 				/* f_bavail x f_frsize / df_disp_hr, show one fractional,
337 				 * use suffixes if df_disp_hr == 0 */
338 				make_human_readable_str(s.f_bavail, s.f_frsize, df_disp_hr),
339 				blocks_percent_used, mount_point);
340 #else
341 			printf(" %9lu %9lu %9lu %3u%% %s\n",
342 				kscale(s.f_blocks, s.f_frsize),
343 				kscale(s.f_blocks - s.f_bfree, s.f_frsize),
344 				kscale(s.f_bavail, s.f_frsize),
345 				blocks_percent_used, mount_point);
346 #endif
347 		}
348 	}
349 
350 	return status;
351 }
352