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loop device code: readability improvement

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This commit is contained in:
Denis Vlasenko 2007-04-19 00:09:34 +00:00
parent 3ace9fa6d8
commit c34d35557b
2 changed files with 20 additions and 13 deletions
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24
libbb/loop.c
View File

@ -84,7 +84,7 @@ int set_loop(char **device, const char *file, unsigned long long offset)
char dev[20], *try;
bb_loop_info loopinfo;
struct stat statbuf;
int i, dfd, ffd, mode, rc=-1;
int i, dfd, ffd, mode, rc = -1;
/* Open the file. Barf if this doesn't work. */
mode = O_RDWR;
@ -98,12 +98,12 @@ int set_loop(char **device, const char *file, unsigned long long offset)
/* Find a loop device. */
try = *device ? : dev;
for (i=0;rc;i++) {
for (i = 0; rc; i++) {
sprintf(dev, LOOP_FORMAT, i);
/* Ran out of block devices, return failure. */
if (stat(try, &statbuf) || !S_ISBLK(statbuf.st_mode)) {
rc=-ENOENT;
rc = -ENOENT;
break;
}
/* Open the sucker and check its loopiness. */
@ -112,19 +112,22 @@ int set_loop(char **device, const char *file, unsigned long long offset)
mode = O_RDONLY;
dfd = open(try, mode);
}
if (dfd < 0) goto try_again;
if (dfd < 0)
goto try_again;
rc = ioctl(dfd, BB_LOOP_GET_STATUS, &loopinfo);
/* If device free, claim it. */
/* If device is free, claim it. */
if (rc && errno == ENXIO) {
memset(&loopinfo, 0, sizeof(loopinfo));
safe_strncpy((char *)loopinfo.lo_file_name, file, LO_NAME_SIZE);
loopinfo.lo_offset = offset;
/* Associate free loop device with file. */
if (!ioctl(dfd, LOOP_SET_FD, ffd)) {
if (!ioctl(dfd, BB_LOOP_SET_STATUS, &loopinfo)) rc = 0;
else ioctl(dfd, LOOP_CLR_FD, 0);
if (!ioctl(dfd, BB_LOOP_SET_STATUS, &loopinfo))
rc = 0;
else
ioctl(dfd, LOOP_CLR_FD, 0);
}
/* If this block device already set up right, re-use it.
@ -132,7 +135,7 @@ int set_loop(char **device, const char *file, unsigned long long offset)
file isn't pretty either. In general, mounting the same file twice
without using losetup manually is problematic.)
*/
} else if (strcmp(file,(char *)loopinfo.lo_file_name)
} else if (strcmp(file, (char *)loopinfo.lo_file_name) != 0
|| offset != loopinfo.lo_offset) {
rc = -1;
}
@ -142,8 +145,9 @@ try_again:
}
close(ffd);
if (!rc) {
if (!*device) *device = xstrdup(dev);
return mode==O_RDONLY ? 1 : 0;
if (!*device)
*device = xstrdup(dev);
return (mode == O_RDONLY) ? 1 : 0;
}
return rc;
}

9
util-linux/losetup.c
View File

@ -45,9 +45,11 @@ int losetup_main(int argc, char **argv)
bb_perror_nomsg_and_die();
} else if (argc == 1) {
char *s = query_loop(argv[0]);
if (!s) bb_perror_nomsg_and_die();
if (!s)
bb_perror_nomsg_and_die();
printf("%s: %s\n", argv[0], s);
if (ENABLE_FEATURE_CLEAN_UP) free(s);
if (ENABLE_FEATURE_CLEAN_UP)
free(s);
} else {
char dev[sizeof(LOOP_NAME"0")] = LOOP_NAME"0";
char c;
@ -57,7 +59,8 @@ int losetup_main(int argc, char **argv)
s = query_loop(dev);
if (s) {
printf("%s: %s\n", dev, s);
if (ENABLE_FEATURE_CLEAN_UP) free(s);
if (ENABLE_FEATURE_CLEAN_UP)
free(s);
}
}
}