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      1 /*
      2  * Copyright (c) International Business Machines  Corp., 2002
      3  * Copyright (c) 2015 Cyril Hrubis <chrubis (at) suse.cz>
      4  *
      5  *  Robbie Williamson <robbiew (at) us.ibm.com>
      6  *  Roy Lee <roylee (at) andestech.com>
      7  *
      8  * This program is free software;  you can redistribute it and/or modify
      9  * it under the terms of the GNU General Public License as published by
     10  * the Free Software Foundation; either version 2 of the License, or
     11  * (at your option) any later version.
     12  *
     13  * This program is distributed in the hope that it will be useful,
     14  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
     15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
     16  * the GNU General Public License for more details.
     17  *
     18  * You should have received a copy of the GNU General Public License
     19  * along with this program;  if not, write to the Free Software Foundation,
     20  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     21  */
     22 
     23 /*
     24  * Tests truncate and mandatory record locking.
     25  *
     26  * Parent creates a file, child locks a region and sleeps.
     27  *
     28  * Parent checks that ftruncate before the locked region and inside the region
     29  * fails while ftruncate after the region succeds.
     30  *
     31  * Parent wakes up child, child exits, lock is unlocked.
     32  *
     33  * Parent checks that ftruncate now works in all cases.
     34  */
     35 
     36 #include <signal.h>
     37 #include <fcntl.h>
     38 #include <unistd.h>
     39 #include <stdio.h>
     40 #include <errno.h>
     41 #include <sys/wait.h>
     42 #include <inttypes.h>
     43 #include <sys/types.h>
     44 #include <sys/stat.h>
     45 #include <sys/mount.h>
     46 #include <sys/statvfs.h>
     47 
     48 #include "test.h"
     49 #include "safe_macros.h"
     50 
     51 #define RECLEN	100
     52 #define MOUNT_DIR "dir/"
     53 
     54 const char *TCID = "ftruncate04";
     55 int TST_TOTAL = 6;
     56 
     57 static int len = 8 * 1024;
     58 static char filename[80];
     59 
     60 static int recstart;
     61 static int reclen;
     62 
     63 static const char *device;
     64 static const char *fs_type;
     65 static int mount_flag;
     66 
     67 static void dochild(void);
     68 static void doparent(void);
     69 static void setup(void);
     70 static void cleanup(void);
     71 
     72 int main(int ac, char **av)
     73 {
     74 	int lc, pid;
     75 
     76 	tst_parse_opts(ac, av, NULL, NULL);
     77 
     78 	setup();
     79 
     80 #ifdef UCLINUX
     81 	maybe_run_child(&dochild, "sdd", filename, &recstart, &reclen);
     82 #endif
     83 
     84 	for (lc = 0; TEST_LOOPING(lc); lc++) {
     85 		sprintf(filename, MOUNT_DIR"%s.%d.%d\n", TCID, getpid(), lc);
     86 
     87 		if (tst_fill_file(filename, 0, 1024, 8)) {
     88 			tst_brkm(TBROK, cleanup,
     89 			         "Failed to create test file '%s'", filename);
     90 		}
     91 
     92 		SAFE_CHMOD(cleanup, filename, 02666);
     93 
     94 		reclen = RECLEN;
     95 		/*
     96 		 * want at least RECLEN bytes BEFORE AND AFTER the
     97 		 * record lock.
     98 		 */
     99 		recstart = RECLEN + rand() % (len - 3 * RECLEN);
    100 
    101 		if ((pid = FORK_OR_VFORK()) < 0)
    102 			tst_brkm(TBROK | TERRNO, cleanup, "fork() failed");
    103 
    104 		if (pid == 0) {
    105 #ifdef UCLINUX
    106 			if (self_exec(av[0], "sdd", filename, recstart,
    107 			              reclen) < -1) {
    108 				tst_brkm(TBROK, cleanup, "self_exec() failed");
    109 			}
    110 #else
    111 			dochild();
    112 #endif
    113 		}
    114 
    115 		doparent();
    116 	}
    117 
    118 	cleanup();
    119 	tst_exit();
    120 }
    121 
    122 static void ftruncate_expect_fail(int fd, off_t offset, const char *msg)
    123 {
    124 	TEST(ftruncate(fd, offset));
    125 
    126 	if (TEST_RETURN == 0) {
    127 		tst_resm(TFAIL, "ftruncate() %s succeeded unexpectedly", msg);
    128 		return;
    129 	}
    130 
    131 	if (TEST_ERRNO != EAGAIN) {
    132 		tst_resm(TFAIL | TTERRNO,
    133 		         "ftruncate() %s failed unexpectedly, expected EAGAIN",
    134 			 msg);
    135 		return;
    136 	}
    137 
    138 	tst_resm(TPASS, "ftruncate() %s failed with EAGAIN", msg);
    139 }
    140 
    141 static void ftruncate_expect_success(int fd, off_t offset, const char *msg)
    142 {
    143 	struct stat sb;
    144 
    145 	TEST(ftruncate(fd, offset));
    146 
    147 	if (TEST_RETURN != 0) {
    148 		tst_resm(TFAIL | TTERRNO,
    149 		         "ftruncate() %s failed unexpectedly", msg);
    150 		return;
    151 	}
    152 
    153 	SAFE_FSTAT(cleanup, fd, &sb);
    154 
    155 	if (sb.st_size != offset) {
    156 		tst_resm(TFAIL,
    157 			 "ftruncate() to %zu bytes succeded but fstat() reports size %zu",
    158 			 offset, sb.st_size);
    159 		return;
    160 	}
    161 
    162 	tst_resm(TPASS, "ftruncate() %s succeded", msg);
    163 }
    164 
    165 static void doparent(void)
    166 {
    167 	int fd;
    168 
    169 	/* Wait for child lock */
    170 	TST_SAFE_CHECKPOINT_WAIT(cleanup, 0);
    171 
    172 	fd = SAFE_OPEN(cleanup, filename, O_RDWR | O_NONBLOCK);
    173 
    174 	ftruncate_expect_fail(fd, RECLEN, "offset before lock");
    175 	ftruncate_expect_fail(fd, recstart + RECLEN/2, "offset in lock");
    176 	ftruncate_expect_success(fd, recstart + RECLEN, "offset after lock");
    177 
    178 	/* wake child and wait for it to exit (to free record lock) */
    179 	TST_SAFE_CHECKPOINT_WAKE(cleanup, 0);
    180 	SAFE_WAIT(NULL, NULL);
    181 
    182 	ftruncate_expect_success(fd, recstart + RECLEN/2, "offset in lock");
    183 	ftruncate_expect_success(fd, recstart, "offset before lock");
    184 	ftruncate_expect_success(fd, recstart + RECLEN, "offset after lock");
    185 
    186 	SAFE_CLOSE(NULL, fd);
    187 }
    188 
    189 void dochild(void)
    190 {
    191 	int fd;
    192 	struct flock flocks;
    193 
    194 #ifdef UCLINUX
    195 	TST_CHECKPOINT_INIT(NULL);
    196 #endif
    197 
    198 	fd = SAFE_OPEN(NULL, filename, O_RDWR);
    199 
    200 	tst_resm(TINFO, "Child locks file");
    201 
    202 	flocks.l_type = F_WRLCK;
    203 	flocks.l_whence = SEEK_CUR;
    204 	flocks.l_start = recstart;
    205 	flocks.l_len = reclen;
    206 
    207 	if (fcntl(fd, F_SETLKW, &flocks) < 0)
    208 		tst_brkm(TFAIL, NULL, "child fcntl failed");
    209 
    210 	TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
    211 
    212 	tst_resm(TINFO, "Child unlocks file");
    213 
    214 	tst_exit();
    215 }
    216 
    217 static void setup(void)
    218 {
    219 	struct statvfs fs;
    220 
    221 	srand(getpid());
    222 
    223 	tst_tmpdir();
    224 
    225 	SAFE_MKDIR(tst_rmdir, MOUNT_DIR, 0777);
    226 
    227 	TST_CHECKPOINT_INIT(tst_rmdir);
    228 
    229 	if (statvfs(".", &fs) == -1)
    230 		tst_brkm(TFAIL | TERRNO, tst_rmdir, "statvfs failed");
    231 
    232 	if ((fs.f_flag & MS_MANDLOCK))
    233 		return;
    234 
    235 	tst_resm(TINFO, "TMPDIR does not support mandatory locks");
    236 
    237 	fs_type = tst_dev_fs_type();
    238 	device = tst_acquire_device(cleanup);
    239 
    240 	if (!device)
    241 		tst_brkm(TCONF, cleanup, "Failed to obtain block device");
    242 
    243 	/* the kernel returns EPERM when CONFIG_MANDATORY_FILE_LOCKING is not
    244 	 * supported - to avoid false negatives, mount the fs first without
    245 	 * flags and then remount it as MS_MANDLOCK */
    246 
    247 	tst_mkfs(cleanup, device, fs_type, NULL, NULL);
    248 	SAFE_MOUNT(cleanup, device, MOUNT_DIR, fs_type, 0, NULL);
    249 	mount_flag = 1;
    250 
    251 	if (mount(NULL, MOUNT_DIR, NULL, MS_REMOUNT|MS_MANDLOCK, NULL) == -1) {
    252 		if (errno == EPERM) {
    253 			tst_brkm(TCONF, cleanup, "Mandatory locking (likely) "
    254 				 "not supported by this system");
    255 		} else {
    256 			tst_brkm(TBROK | TERRNO, cleanup,
    257 				 "Remount with MS_MANDLOCK failed");
    258 		}
    259 	}
    260 }
    261 
    262 static void cleanup(void)
    263 {
    264 	if (mount_flag && tst_umount(MOUNT_DIR))
    265 		tst_resm(TWARN | TERRNO, "umount(%s) failed", device);
    266 
    267 	if (device)
    268 		tst_release_device(device);
    269 
    270 	tst_rmdir();
    271 }
    272