diff options
Diffstat (limited to 'util-linux/mount.c')
| -rw-r--r-- | util-linux/mount.c | 62 |
1 files changed, 61 insertions, 1 deletions
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 ); |