From 4928e9f7d0a17898300f20567a331417fafc16c1 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 27 Jun 2013 03:45:16 +0200 Subject: [PATCH] losetup: assorted fixes. Closes 6314 "losetup -d" was not complaining that LOOPDEV is missing. "losetup -a" was listing only up to /dev/loop9. "losetup -f" looped forever if llop0 was taken, and never tried anything after /dev/loop9. "-o" with other options (say, -r) had no effect. function old new delta losetup_main 376 419 +43 Signed-off-by: Denys Vlasenko --- include/libbb.h | 4 ++-- util-linux/losetup.c | 37 +++++++++++++++++++++---------------- 2 files changed, 23 insertions(+), 18 deletions(-) diff --git a/include/libbb.h b/include/libbb.h index b5d1156ae..65c6b9f39 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -1803,7 +1803,7 @@ extern const char bb_default_login_shell[] ALIGN1; # define VC_4 "/dev/vc/4" # define VC_5 "/dev/vc/5" # define VC_FORMAT "/dev/vc/%d" -# define LOOP_FORMAT "/dev/loop/%d" +# define LOOP_FORMAT "/dev/loop/%u" # define LOOP_NAMESIZE (sizeof("/dev/loop/") + sizeof(int)*3 + 1) # define LOOP_NAME "/dev/loop/" # define FB_0 "/dev/fb/0" @@ -1816,7 +1816,7 @@ extern const char bb_default_login_shell[] ALIGN1; # define VC_4 "/dev/tty4" # define VC_5 "/dev/tty5" # define VC_FORMAT "/dev/tty%d" -# define LOOP_FORMAT "/dev/loop%d" +# define LOOP_FORMAT "/dev/loop%u" # define LOOP_NAMESIZE (sizeof("/dev/loop") + sizeof(int)*3 + 1) # define LOOP_NAME "/dev/loop" # define FB_0 "/dev/fb0" diff --git a/util-linux/losetup.c b/util-linux/losetup.c index c69763335..d450b5a78 100644 --- a/util-linux/losetup.c +++ b/util-linux/losetup.c @@ -10,12 +10,12 @@ //usage:#define losetup_trivial_usage //usage: "[-r] [-o OFS] {-f|LOOPDEV} FILE - associate loop devices\n" //usage: " losetup -d LOOPDEV - disassociate\n" -//usage: " losetup -a - show status of all\n" -//usage: " losetup -f - show next available" +//usage: " losetup -a - show status\n" +//usage: " losetup -f - show next free loop device" //usage:#define losetup_full_usage "\n\n" //usage: " -o OFS Start OFS bytes into FILE" //usage: "\n -r Read-only" -//usage: "\n -f Show/find first free loop device" +//usage: "\n -f Show/use next free loop device" //usage: //usage:#define losetup_notes_usage //usage: "One argument (losetup /dev/loop1) will display the current association\n" @@ -27,6 +27,10 @@ #include "libbb.h" +/* 1048575 is a max possible minor number in Linux circa 2010 */ +/* for now use something less extreme */ +#define MAX_LOOP_NUM 1023 + int losetup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int losetup_main(int argc UNUSED_PARAM, char **argv) { @@ -59,7 +63,7 @@ int losetup_main(int argc UNUSED_PARAM, char **argv) } /* -d LOOPDEV */ - if (opt == OPT_d) { + if (opt == OPT_d && argv[0]) { if (del_loop(argv[0])) bb_simple_perror_msg_and_die(argv[0]); return EXIT_SUCCESS; @@ -68,15 +72,14 @@ int losetup_main(int argc UNUSED_PARAM, char **argv) /* -a */ if (opt == OPT_a) { int n; - for (n = 0; n < 10; n++) { + for (n = 0; n < MAX_LOOP_NUM; n++) { char *s; sprintf(dev, LOOP_FORMAT, n); s = query_loop(dev); if (s) { printf("%s: %s\n", dev, s); - if (ENABLE_FEATURE_CLEAN_UP) - free(s); + free(s); } } return EXIT_SUCCESS; @@ -88,11 +91,13 @@ int losetup_main(int argc UNUSED_PARAM, char **argv) int n = 0; do { - sprintf(dev, LOOP_FORMAT, n); + if (n > MAX_LOOP_NUM) + bb_error_msg_and_die("no free loop devices"); + sprintf(dev, LOOP_FORMAT, n++); s = query_loop(dev); - if (s && ENABLE_FEATURE_CLEAN_UP) - free(s); + free(s); } while (s); + /* now: dev is next free "/dev/loopN" */ if ((opt == OPT_f) && !argv[0]) { puts(dev); return EXIT_SUCCESS; @@ -104,18 +109,18 @@ int losetup_main(int argc UNUSED_PARAM, char **argv) unsigned long long offset = 0; char *d = dev; - if (opt == OPT_o) + if (opt & OPT_o) offset = xatoull(opt_o); - if (opt != OPT_f) - d = *(argv++); + if (!(opt & OPT_f)) + d = *argv++; if (argv[0]) { - if (set_loop(&d, argv[0], offset, (opt / OPT_r)) < 0) + if (set_loop(&d, argv[0], offset, (opt & OPT_r)) < 0) bb_simple_perror_msg_and_die(argv[0]); return EXIT_SUCCESS; } } - bb_show_usage(); - return EXIT_FAILURE; + bb_show_usage(); /* does not return */ + /*return EXIT_FAILURE;*/ }