diff options
| -rw-r--r-- | include/libbb.h | 3 | ||||
| -rw-r--r-- | libbb/loop.c | 4 | ||||
| -rw-r--r-- | util-linux/losetup.c | 2 | ||||
| -rw-r--r-- | util-linux/mount.c | 62 |
4 files changed, 67 insertions, 4 deletions
diff --git a/include/libbb.h b/include/libbb.h index 8c79784..83ecca4 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -1515,7 +1515,8 @@ int del_loop(const char *device) FAST_FUNC; * malloc and return it in *devname. * return value is the opened fd to the loop device, or < on error */ -int set_loop(char **devname, const char *file, unsigned long long offset, unsigned flags) FAST_FUNC; +int set_loop(char **devname, const char *file, unsigned long long offset, + unsigned long long sizelimit, unsigned flags) FAST_FUNC; /* These constants match linux/loop.h (without BB_ prefix): */ #define BB_LO_FLAGS_READ_ONLY 1 #define BB_LO_FLAGS_AUTOCLEAR 4 diff --git a/libbb/loop.c b/libbb/loop.c index ada0c76..85b2724 100644 --- a/libbb/loop.c +++ b/libbb/loop.c @@ -102,7 +102,8 @@ int FAST_FUNC get_free_loop(void) * 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, unsigned flags) +int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offset, + unsigned long long sizelimit, unsigned flags) { char dev[LOOP_NAMESIZE]; char *try; @@ -185,6 +186,7 @@ int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offse memset(&loopinfo, 0, sizeof(loopinfo)); safe_strncpy((char *)loopinfo.lo_file_name, file, LO_NAME_SIZE); loopinfo.lo_offset = offset; + loopinfo.lo_sizelimit = sizelimit; /* * Used by mount to set LO_FLAGS_AUTOCLEAR. * LO_FLAGS_READ_ONLY is not set because RO is controlled by open type of the file. diff --git a/util-linux/losetup.c b/util-linux/losetup.c index ac8b795..24f7a23 100644 --- a/util-linux/losetup.c +++ b/util-linux/losetup.c @@ -150,7 +150,7 @@ int losetup_main(int argc UNUSED_PARAM, char **argv) if (opt & OPT_P) { flags |= BB_LO_FLAGS_PARTSCAN; } - if (set_loop(&d, argv[0], offset, flags) < 0) + if (set_loop(&d, argv[0], offset, 0, flags) < 0) bb_simple_perror_msg_and_die(argv[0]); return EXIT_SUCCESS; } diff --git a/util-linux/mount.c b/util-linux/mount.c index b92e2c2..19ac139 100644 --- a/util-linux/mount.c +++ b/util-linux/mount.c @@ -1886,6 +1886,58 @@ static int nfsmount(struct mntent *mp, unsigned long vfsflags, char *filteropts) #endif // !ENABLE_FEATURE_MOUNT_NFS +// Find "...,NAME=NUM,..." in the option string, remove "NAME=NUM" option +// and return NUM. +// Return 0 if not found. +// All instances must be parsed and removed (for example, since kernel 5.4 +// squashfs: Unknown parameter 'sizelimit' +// will result if loopback mount option "sizelimit=NNN" is not removed +// and squashfs sees it in option string). +static unsigned long long cut_out_ull_opt(char *opts, const char *name_eq) +{ + unsigned long long ret = 0; + + if (!opts) // allow NULL opts (simplifies callers' work) + return ret; + + for (;;) { + char *end; + char *opt; + + // Find comma-delimited "NAME=" + for (;;) { + opt = strstr(opts, name_eq); + if (!opt) + return ret; + if (opt == opts) + break; // found it (it's first opt) + if (opt[-1] == ',') { + opts = opt - 1; + break; // found it (it's not a first opt) + } + // False positive like "VNAME=", we are at "N". + // - skip it, loop back to searching + opts = opt + 1; + } + + ret = bb_strtoull(opt + strlen(name_eq), &end, 0); + if (errno && errno != EINVAL) { + err: + bb_error_msg_and_die("bad option '%s'", opt); + } + if (*end == '\0') { + // It is "[,]NAME=NUM\0" - truncate it and return + *opts = '\0'; + return ret; + } + if (*end != ',') + goto err; + // We are at trailing comma + // Remove "NAME=NUM," and loop back to check for duplicate opts + overlapping_strcpy(opt, end + 1); + } +} + // Mount one directory. Handles CIFS, NFS, loopback, autobind, and filesystem // type detection. Returns 0 for success, nonzero for failure. // NB: mp->xxx fields may be trashed on exit @@ -2029,9 +2081,16 @@ static int singlemount(struct mntent *mp, int ignore_busy) ) { // Do we need to allocate a loopback device for it? if (ENABLE_FEATURE_MOUNT_LOOP && S_ISREG(st.st_mode)) { + unsigned long long offset; + unsigned long long sizelimit; + loopFile = bb_simplify_path(mp->mnt_fsname); mp->mnt_fsname = NULL; // will receive malloced loop dev name + // Parse and remove loopback options + offset = cut_out_ull_opt(filteropts, "offset="); + sizelimit = cut_out_ull_opt(filteropts, "sizelimit="); + // mount always creates AUTOCLEARed loopdevs, so that umounting // drops them without any code in the userspace. // This happens since circa linux-2.6.25: @@ -2040,7 +2099,8 @@ static int singlemount(struct mntent *mp, int ignore_busy) // Subject: Allow auto-destruction of loop devices loopfd = set_loop(&mp->mnt_fsname, loopFile, - 0, + offset, + sizelimit, ((vfsflags & MS_RDONLY) ? BB_LO_FLAGS_READ_ONLY : 0) | BB_LO_FLAGS_AUTOCLEAR ); |