From 13e709c53f700a18a660feebdf72c613a233bf48 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Mon, 12 Sep 2011 02:13:47 +0200 Subject: [PATCH] losetup: implement -r option. Closes 4033. function old new delta packed_usage 28595 28633 +38 losetup_main 285 290 +5 singlemount 906 908 +2 set_loop 674 672 -2 Signed-off-by: Denys Vlasenko --- include/libbb.h | 2 +- libbb/loop.c | 10 ++++++---- util-linux/losetup.c | 16 +++++++++------- util-linux/mount.c | 2 +- 4 files changed, 17 insertions(+), 13 deletions(-) diff --git a/include/libbb.h b/include/libbb.h index 21cbe1c..feae852 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -1164,7 +1164,7 @@ extern int del_loop(const char *device) FAST_FUNC; /* If *devname is not NULL, use that name, otherwise try to find free one, * malloc and return it in *devname. * return value: 1: read-only loopdev was setup, 0: rw, < 0: error */ -extern int set_loop(char **devname, const char *file, unsigned long long offset) FAST_FUNC; +extern int set_loop(char **devname, const char *file, unsigned long long offset, int ro) FAST_FUNC; /* Like bb_ask below, but asks on stdin with no timeout. */ char *bb_ask_stdin(const char * prompt) FAST_FUNC; diff --git a/libbb/loop.c b/libbb/loop.c index b798932..b3a5208 100644 --- a/libbb/loop.c +++ b/libbb/loop.c @@ -84,7 +84,7 @@ int FAST_FUNC del_loop(const char *device) search will re-use an existing loop device already bound to that file/offset if it finds one. */ -int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offset) +int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offset, int ro) { char dev[LOOP_NAMESIZE]; char *try; @@ -93,11 +93,13 @@ int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offse int i, dfd, ffd, mode, rc = -1; /* Open the file. Barf if this doesn't work. */ - mode = O_RDWR; + mode = ro ? O_RDONLY : O_RDWR; ffd = open(file, mode); if (ffd < 0) { - mode = O_RDONLY; - ffd = open(file, mode); + if (mode != O_RDONLY) { + mode = O_RDONLY; + ffd = open(file, mode); + } if (ffd < 0) return -errno; } diff --git a/util-linux/losetup.c b/util-linux/losetup.c index 9b7c49f..21108d0 100644 --- a/util-linux/losetup.c +++ b/util-linux/losetup.c @@ -8,11 +8,12 @@ */ //usage:#define losetup_trivial_usage -//usage: "[-o OFS] LOOPDEV FILE - associate loop devices\n" +//usage: "[-r] [-o OFS] LOOPDEV FILE - associate loop devices\n" //usage: " losetup -d LOOPDEV - disassociate\n" //usage: " losetup [-f] - show" //usage:#define losetup_full_usage "\n\n" //usage: " -o OFS Start OFS bytes into FILE" +//usage: "\n -r Read-only" //usage: "\n -f Show first free loop device" //usage: //usage:#define losetup_notes_usage @@ -37,11 +38,12 @@ int losetup_main(int argc UNUSED_PARAM, char **argv) OPT_d = (1 << 0), OPT_o = (1 << 1), OPT_f = (1 << 2), + OPT_r = (1 << 3), /* must be last */ }; - /* max 2 args, all opts are mutually exclusive */ + /* max 2 args, -d,-o,-f opts are mutually exclusive */ opt_complementary = "?2:d--of:o--df:f--do"; - opt = getopt32(argv, "do:f", &opt_o); + opt = getopt32(argv, "do:fr", &opt_o); argv += optind; if (opt == OPT_o) @@ -63,12 +65,12 @@ int losetup_main(int argc UNUSED_PARAM, char **argv) bb_show_usage(); if (argv[1]) { - /* [-o OFS] BLOCKDEV FILE */ - if (set_loop(&argv[0], argv[1], offset) < 0) + /* [-r] [-o OFS] BLOCKDEV FILE */ + if (set_loop(&argv[0], argv[1], offset, (opt / OPT_r)) < 0) bb_simple_perror_msg_and_die(argv[0]); return EXIT_SUCCESS; } - /* [-o OFS] BLOCKDEV */ + /* [-r] [-o OFS] BLOCKDEV */ s = query_loop(argv[0]); if (!s) bb_simple_perror_msg_and_die(argv[0]); @@ -78,7 +80,7 @@ int losetup_main(int argc UNUSED_PARAM, char **argv) return EXIT_SUCCESS; } - /* [-o OFS|-f] with no params */ + /* [-r] [-o OFS|-f] with no params */ n = 0; while (1) { char *s; diff --git a/util-linux/mount.c b/util-linux/mount.c index 05e532c..b51ab17 100644 --- a/util-linux/mount.c +++ b/util-linux/mount.c @@ -1809,7 +1809,7 @@ static int singlemount(struct mntent *mp, int ignore_busy) if (ENABLE_FEATURE_MOUNT_LOOP && S_ISREG(st.st_mode)) { loopFile = bb_simplify_path(mp->mnt_fsname); mp->mnt_fsname = NULL; // will receive malloced loop dev name - if (set_loop(&mp->mnt_fsname, loopFile, 0) < 0) { + if (set_loop(&mp->mnt_fsname, loopFile, 0, /*ro:*/ 0) < 0) { if (errno == EPERM || errno == EACCES) bb_error_msg(bb_msg_perm_denied_are_you_root); else -- 2.7.4