# HG changeset patch # User Rob Landley # Date 1410136398 18000 # Node ID 83cbfc4b0de7b72ede54913601f2d427b4104f3d # Parent 67c1402e9723afbc98485c4eaa011441f112dff6 Promote mount. It's not perfect, but it basically works now. diff -r 67c1402e9723 -r 83cbfc4b0de7 toys/lsb/mount.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toys/lsb/mount.c Sun Sep 07 19:33:18 2014 -0500 @@ -0,0 +1,325 @@ +/* mount.c - mount filesystems + * + * Copyright 2014 Rob Landley + * + * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/mount.html + * Note: -hV is bad spec, haven't implemented -FsLU yet + * no mtab (/proc/mounts does it) so -n is NOP. + +USE_MOUNT(NEWTOY(mount, "?O:afnrvwt:o*[-rw]", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_STAYROOT)) + +config MOUNT + bool "mount" + default y + help + usage: mount [-afFrsvw] [-t TYPE] [-o OPTIONS...] [[DEVICE] DIR] + + Mount new filesystem(s) on directories. With no arguments, display existing + mounts. + + -a mount all entries in /etc/fstab (with -t, only entries of that TYPE) + -O only mount -a entries that have this option + -f fake it (don't actually mount) + -r read only (same as -o ro) + -w read/write (default, same as -o rw) + -t specify filesystem type + -v verbose + + OPTIONS is a comma separated list of options, which can also be supplied + as --longopts. + + This mount autodetects loopback mounts (a file on a directory) and + bind mounts (file on file, directory on directory), so you don't need + to say --bind or --loop. You can also "mount -a /path" to mount everything + in /etc/fstab under /path, even if it's noauto. +*/ + +#define FOR_mount +#include "toys.h" + +GLOBALS( + struct arg_list *optlist; + char *type; + char *bigO; + + unsigned long flags; + char *opts; + int okuser; +) + +// TODO detect existing identical mount (procfs with different dev name?) +// TODO user, users, owner, group, nofail +// TODO -p (passfd) +// TODO -a -t notype,type2 +// TODO --subtree +// TODO --rbind, -R +// TODO make "mount --bind,ro old new" work (implicit -o remount) +// TODO mount -a +// TODO mount -o remount +// TODO fstab: lookup default options for mount +// TODO implement -v +// TODO "mount -a -o remount,ro" should detect overmounts +// TODO work out how that differs from "mount -ar" +// TODO what if you --bind mount a block device somewhere (file, dir, dev) +// TODO "touch servername; mount -t cifs servername path" + +// Strip flags out of comma separated list of options, return flags,. +static long flag_opts(char *new, long flags, char **more) +{ + struct { + char *name; + long flags; + } opts[] = { + // NOPs (we autodetect --loop and --bind) + {"loop", 0}, {"bind", 0}, {"defaults", 0}, {"quiet", 0}, + {"user", 0}, {"nouser", 0}, // checked in fstab, ignored in -o +// {"noauto", 0}, {"swap", 0}, + {"ro", MS_RDONLY}, {"rw", ~MS_RDONLY}, + {"nosuid", MS_NOSUID}, {"suid", ~MS_NOSUID}, + {"nodev", MS_NODEV}, {"dev", ~MS_NODEV}, + {"noexec", MS_NOEXEC}, {"exec", ~MS_NOEXEC}, + {"sync", MS_SYNCHRONOUS}, {"async", ~MS_SYNCHRONOUS}, + {"noatime", MS_NOATIME}, {"atime", ~MS_NOATIME}, + {"nodiratime", MS_NODIRATIME}, {"diratime", ~MS_NODIRATIME}, + {"loud", ~MS_SILENT}, + {"shared", MS_SHARED}, {"rshared", MS_SHARED|MS_REC}, + {"slave", MS_SLAVE}, {"rslave", MS_SLAVE|MS_REC}, + {"private", MS_PRIVATE}, {"rprivate", MS_SLAVE|MS_REC}, + {"unbindable", MS_UNBINDABLE}, {"runbindable", MS_UNBINDABLE|MS_REC}, + {"remount", MS_REMOUNT}, {"move", MS_MOVE}, + // mand dirsync rec iversion strictatime + }; + + if (new) for (;;) { + char *comma = strchr(new, ','); + int i; + + if (comma) *comma = 0; + + // If we recognize an option, apply flags + for (i = 0; i < ARRAY_LEN(opts); i++) if (!strcasecmp(opts[i].name, new)) { + long ll = opts[i].flags; + + if (ll < 0) flags &= ll; + else flags |= ll; + + break; + } + + // If we didn't recognize it, keep string version + if (more && i == ARRAY_LEN(opts)) { + i = *more ? strlen(*more) : 0; + *more = xrealloc(*more, i + strlen(new) + 2); + if (i) (*more)[i++] = ','; + strcpy(i+*more, new); + } + + if (!comma) break; + *comma = ','; + new = comma + 1; + } + + return flags; +} + +static void mount_filesystem(char *dev, char *dir, char *type, + unsigned long flags, char *opts) +{ + FILE *fp = 0; + int rc = EINVAL; + + if (toys.optflags & FLAG_f) return; + + if (getuid()) { + if (TT.okuser) TT.okuser = 0; + else { + error_msg("'%s' not user mountable in fstab"); + return; + } + } + + // Autodetect bind mount or filesystem type + + if (type && !strcmp(type, "auto")) type = 0; + if (flags & MS_MOVE) { + if (type) error_exit("--move with -t"); + } else if (!type) { + struct stat stdev, stdir; + + // file on file or dir on dir is a --bind mount. + if (!stat(dev, &stdev) && !stat(dir, &stdir) + && ((S_ISREG(stdev.st_mode) && S_ISREG(stdir.st_mode)) + || (S_ISDIR(stdev.st_mode) && S_ISDIR(stdir.st_mode)))) + { + flags |= MS_BIND; + } else fp = xfopen("/proc/filesystems", "r"); + } else if (!strcmp(type, "ignore")) return; + else if (!strcmp(type, "swap")) + toys.exitval |= xpclose(xpopen((char *[]){"swapon", "--", dev, 0}, 0), 0); + + for (;;) { + char *buf = 0; + + // If type wasn't specified, try all of them in order. + if (fp) { + size_t i; + + if (getline(&buf, &i, fp)<0) break; + type = buf; + // skip nodev devices + if (!isspace(*type)) { + free(buf); + continue; + } + // trim whitespace + while (isspace(*type)) type++; + i = strlen(type); + if (i) type[i-1] = 0; + } + if (toys.optflags & FLAG_v) + printf("try '%s' type '%s' on '%s'\n", dev, type, dir); + for (;;) { + rc = mount(dev, dir, type, flags, opts); + if ((rc != EACCES && rc != EROFS) || (flags & MS_RDONLY)) break; + fprintf(stderr, "'%s' is read-only", dev); + flags |= MS_RDONLY; + } + free(buf); + + if (!rc) break; + + // Trying to autodetect loop mounts like bind mounts above (file on dir) + // isn't good enough because "mount -t ext2 fs.img dir" is valid, but if + // you _do_ accept loop mounts with -t how do you tell "-t cifs" isn't + // looking for a block device if it's not in /proc/filesystems yet + // because the module that won't be loaded until you try the mount, and + // if you can't then DEVICE existing as a file would cause a false + // positive loopback mount (so "touch servername" becomes a potential + // denial of service attack...) + // + // Solution: try the mount, let the kernel tell us it wanted a block + // device, then do the loopback setup and retry the mount. + + if (fp && errno == EINVAL) continue; + + if (errno == ENOTBLK) { + char *losetup[] = {"losetup", "-fs", dev, 0}; + int pipes[2], len; + pid_t pid; + + if (flags & MS_RDONLY) losetup[1] = "-fsr"; + pid = xpopen(losetup, pipes); + len = readall(pipes[1], toybuf, sizeof(toybuf)-1); + rc = xpclose(pid, pipes); + if (!rc && len > 1) { + if (toybuf[len-1] == '\n') --len; + toybuf[len] = 0; + dev = toybuf; + + continue; + } else error_msg("losetup failed %d", rc); + } else perror_msg("'%s'->'%s'", dev, dir); + + break; + } + if (fp) fclose(fp); +} + +void mount_main(void) +{ + char *opts = 0, *dev = 0, *dir = 0, **ss; + long flags = MS_SILENT; + struct arg_list *o; + struct mtab_list *mtl, *mm, *remount = 0; + +// remount +// - overmounts +// shared subtree +// -o parsed after fstab options +// test if mountpoint already exists (-o noremount?) + + // First pass; just accumulate string, don't parse flags yet. (This is so + // we can modify fstab entries with -a, or mtab with remount.) + for (o = TT.optlist; o; o = o->next) comma_collate(&opts, o->arg); + if (toys.optflags & FLAG_r) comma_collate(&opts, "ro"); + if (toys.optflags & FLAG_w) comma_collate(&opts, "rw"); + + // Treat each --option as -o option + for (ss = toys.optargs; *ss; ss++) { + char *sss = *ss; + + // If you realy, really want to mount a file named "--", we support it. + if (sss[0]=='-' && sss[1]=='-' && sss[2]) comma_collate(&opts, sss+2); + else if (!dev) dev = sss; + else if (!dir) dir = sss; + // same message as lib/args.c ">2" which we can't use because --opts count + else error_exit("Max 2 arguments\n"); + } + + if ((toys.optflags & FLAG_a) && dir) error_exit("-a with >1 arg"); + + // For remount we need _last_ match (in case of overmounts), so traverse + // in reverse order. + if (comma_scan(opts, "remount", 1)) + remount = dlist_terminate(mtl = xgetmountlist("/proc/mounts")); + + // Do we need to do an /etc/fstab trawl? + // This covers -a, -o remount, one argument, all user mounts + if ((toys.optflags & FLAG_a) || (dev && (!dir || getuid() || remount))) { + if (!remount) mtl = xgetmountlist("/etc/fstab"); + + for (mm = remount ? remount : mtl; mm; mm = (remount ? mm->prev : mm->next)) + { + int aflags, noauto, len; + char *aopts = 0; + + // Check for noauto and get it out of the option list. (Unknown options + // that make it to the kernel give filesystem drivers indigestion.) + noauto = comma_scan(mm->opts, "noauto", 1); + if (toys.optflags & FLAG_a) { + // "mount -a /path" to mount all entries under /path + if (dev) { + len = strlen(dev); + if (strncmp(dev, mm->dir, len) + || (mm->dir[len] && mm->dir[len] != '/')) continue; + } else if (noauto) continue; // never present in the remount case + if (!mountlist_istype(mm,TT.type) || !comma_scanall(mm->opts,TT.bigO)) + continue; + } else { + if (dir && strcmp(dir, mm->dir)) continue; + if (dev && strcmp(dev, mm->device) && (dir || strcmp(dev, mm->dir))) + continue; + } + + // user only counts from fstab, not opts. + TT.okuser = comma_scan(mm->opts, "user", 1); + aflags = flag_opts(mm->opts, flags, &aopts); + aflags = flag_opts(opts, aflags, &aopts); + + mount_filesystem(mm->device, mm->dir, mm->type, aflags, aopts); + free(aopts); + + if (!(toys.optflags & FLAG_a)) break; + } + if (CFG_TOYBOX_FREE) llist_traverse(mtl, free); + + // show mounts from /proc/mounts + } else if (!dev) { + for (mtl = xgetmountlist(0); mtl && (mm = dlist_pop(&mtl)); free(mm)) { + char *s = 0; + + if (TT.type && strcmp(TT.type, mm->type)) continue; + if (*mm->device == '/') s = xabspath(mm->device, 0); + xprintf("%s on %s type %s (%s)\n", + s ? s : mm->device, mm->dir, mm->type, mm->opts); + free(s); + } + + // two arguments + } else { + char *more = 0; + + mount_filesystem(dev, dir, TT.type, flag_opts(opts, flags, &more), more); + if (CFG_TOYBOX_FREE) free(more); + } +} diff -r 67c1402e9723 -r 83cbfc4b0de7 toys/pending/mount.c --- a/toys/pending/mount.c Sun Sep 07 19:30:05 2014 -0500 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,325 +0,0 @@ -/* mount.c - mount filesystems - * - * Copyright 2014 Rob Landley - * - * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/mount.html - * Note: -hV is bad spec, haven't implemented -FsLU yet - * no mtab (/proc/mounts does it) so -n is NOP. - -USE_MOUNT(NEWTOY(mount, "?O:afnrvwt:o*[-rw]", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_STAYROOT)) - -config MOUNT - bool "mount" - default n - help - usage: mount [-afFrsvw] [-t TYPE] [-o OPTIONS...] [[DEVICE] DIR] - - Mount new filesystem(s) on directories. With no arguments, display existing - mounts. - - -a mount all entries in /etc/fstab (with -t, only entries of that TYPE) - -O only mount -a entries that have this option - -f fake it (don't actually mount) - -r read only (same as -o ro) - -w read/write (default, same as -o rw) - -t specify filesystem type - -v verbose - - OPTIONS is a comma separated list of options, which can also be supplied - as --longopts. - - This mount autodetects loopback mounts (a file on a directory) and - bind mounts (file on file, directory on directory), so you don't need - to say --bind or --loop. You can also "mount -a /path" to mount everything - in /etc/fstab under /path, even if it's noauto. -*/ - -#define FOR_mount -#include "toys.h" - -GLOBALS( - struct arg_list *optlist; - char *type; - char *bigO; - - unsigned long flags; - char *opts; - int okuser; -) - -// TODO detect existing identical mount (procfs with different dev name?) -// TODO user, users, owner, group, nofail -// TODO -p (passfd) -// TODO -a -t notype,type2 -// TODO --subtree -// TODO --rbind, -R -// TODO make "mount --bind,ro old new" work (implicit -o remount) -// TODO mount -a -// TODO mount -o remount -// TODO fstab: lookup default options for mount -// TODO implement -v -// TODO "mount -a -o remount,ro" should detect overmounts -// TODO work out how that differs from "mount -ar" -// TODO what if you --bind mount a block device somewhere (file, dir, dev) -// TODO "touch servername; mount -t cifs servername path" - -// Strip flags out of comma separated list of options, return flags,. -static long flag_opts(char *new, long flags, char **more) -{ - struct { - char *name; - long flags; - } opts[] = { - // NOPs (we autodetect --loop and --bind) - {"loop", 0}, {"bind", 0}, {"defaults", 0}, {"quiet", 0}, - {"user", 0}, {"nouser", 0}, // checked in fstab, ignored in -o -// {"noauto", 0}, {"swap", 0}, - {"ro", MS_RDONLY}, {"rw", ~MS_RDONLY}, - {"nosuid", MS_NOSUID}, {"suid", ~MS_NOSUID}, - {"nodev", MS_NODEV}, {"dev", ~MS_NODEV}, - {"noexec", MS_NOEXEC}, {"exec", ~MS_NOEXEC}, - {"sync", MS_SYNCHRONOUS}, {"async", ~MS_SYNCHRONOUS}, - {"noatime", MS_NOATIME}, {"atime", ~MS_NOATIME}, - {"nodiratime", MS_NODIRATIME}, {"diratime", ~MS_NODIRATIME}, - {"loud", ~MS_SILENT}, - {"shared", MS_SHARED}, {"rshared", MS_SHARED|MS_REC}, - {"slave", MS_SLAVE}, {"rslave", MS_SLAVE|MS_REC}, - {"private", MS_PRIVATE}, {"rprivate", MS_SLAVE|MS_REC}, - {"unbindable", MS_UNBINDABLE}, {"runbindable", MS_UNBINDABLE|MS_REC}, - {"remount", MS_REMOUNT}, {"move", MS_MOVE}, - // mand dirsync rec iversion strictatime - }; - - if (new) for (;;) { - char *comma = strchr(new, ','); - int i; - - if (comma) *comma = 0; - - // If we recognize an option, apply flags - for (i = 0; i < ARRAY_LEN(opts); i++) if (!strcasecmp(opts[i].name, new)) { - long ll = opts[i].flags; - - if (ll < 0) flags &= ll; - else flags |= ll; - - break; - } - - // If we didn't recognize it, keep string version - if (more && i == ARRAY_LEN(opts)) { - i = *more ? strlen(*more) : 0; - *more = xrealloc(*more, i + strlen(new) + 2); - if (i) (*more)[i++] = ','; - strcpy(i+*more, new); - } - - if (!comma) break; - *comma = ','; - new = comma + 1; - } - - return flags; -} - -static void mount_filesystem(char *dev, char *dir, char *type, - unsigned long flags, char *opts) -{ - FILE *fp = 0; - int rc = EINVAL; - - if (toys.optflags & FLAG_f) return; - - if (getuid()) { - if (TT.okuser) TT.okuser = 0; - else { - error_msg("'%s' not user mountable in fstab"); - return; - } - } - - // Autodetect bind mount or filesystem type - - if (type && !strcmp(type, "auto")) type = 0; - if (flags & MS_MOVE) { - if (type) error_exit("--move with -t"); - } else if (!type) { - struct stat stdev, stdir; - - // file on file or dir on dir is a --bind mount. - if (!stat(dev, &stdev) && !stat(dir, &stdir) - && ((S_ISREG(stdev.st_mode) && S_ISREG(stdir.st_mode)) - || (S_ISDIR(stdev.st_mode) && S_ISDIR(stdir.st_mode)))) - { - flags |= MS_BIND; - } else fp = xfopen("/proc/filesystems", "r"); - } else if (!strcmp(type, "ignore")) return; - else if (!strcmp(type, "swap")) - toys.exitval |= xpclose(xpopen((char *[]){"swapon", "--", dev, 0}, 0), 0); - - for (;;) { - char *buf = 0; - - // If type wasn't specified, try all of them in order. - if (fp) { - size_t i; - - if (getline(&buf, &i, fp)<0) break; - type = buf; - // skip nodev devices - if (!isspace(*type)) { - free(buf); - continue; - } - // trim whitespace - while (isspace(*type)) type++; - i = strlen(type); - if (i) type[i-1] = 0; - } - if (toys.optflags & FLAG_v) - printf("try '%s' type '%s' on '%s'\n", dev, type, dir); - for (;;) { - rc = mount(dev, dir, type, flags, opts); - if ((rc != EACCES && rc != EROFS) || (flags & MS_RDONLY)) break; - fprintf(stderr, "'%s' is read-only", dev); - flags |= MS_RDONLY; - } - free(buf); - - if (!rc) break; - - // Trying to autodetect loop mounts like bind mounts above (file on dir) - // isn't good enough because "mount -t ext2 fs.img dir" is valid, but if - // you _do_ accept loop mounts with -t how do you tell "-t cifs" isn't - // looking for a block device if it's not in /proc/filesystems yet - // because the module that won't be loaded until you try the mount, and - // if you can't then DEVICE existing as a file would cause a false - // positive loopback mount (so "touch servername" becomes a potential - // denial of service attack...) - // - // Solution: try the mount, let the kernel tell us it wanted a block - // device, then do the loopback setup and retry the mount. - - if (fp && errno == EINVAL) continue; - - if (errno == ENOTBLK) { - char *losetup[] = {"losetup", "-fs", dev, 0}; - int pipes[2], len; - pid_t pid; - - if (flags & MS_RDONLY) losetup[1] = "-fsr"; - pid = xpopen(losetup, pipes); - len = readall(pipes[1], toybuf, sizeof(toybuf)-1); - rc = xpclose(pid, pipes); - if (!rc && len > 1) { - if (toybuf[len-1] == '\n') --len; - toybuf[len] = 0; - dev = toybuf; - - continue; - } else error_msg("losetup failed %d", rc); - } else perror_msg("'%s'->'%s'", dev, dir); - - break; - } - if (fp) fclose(fp); -} - -void mount_main(void) -{ - char *opts = 0, *dev = 0, *dir = 0, **ss; - long flags = MS_SILENT; - struct arg_list *o; - struct mtab_list *mtl, *mm, *remount = 0; - -// remount -// - overmounts -// shared subtree -// -o parsed after fstab options -// test if mountpoint already exists (-o noremount?) - - // First pass; just accumulate string, don't parse flags yet. (This is so - // we can modify fstab entries with -a, or mtab with remount.) - for (o = TT.optlist; o; o = o->next) comma_collate(&opts, o->arg); - if (toys.optflags & FLAG_r) comma_collate(&opts, "ro"); - if (toys.optflags & FLAG_w) comma_collate(&opts, "rw"); - - // Treat each --option as -o option - for (ss = toys.optargs; *ss; ss++) { - char *sss = *ss; - - // If you realy, really want to mount a file named "--", we support it. - if (sss[0]=='-' && sss[1]=='-' && sss[2]) comma_collate(&opts, sss+2); - else if (!dev) dev = sss; - else if (!dir) dir = sss; - // same message as lib/args.c ">2" which we can't use because --opts count - else error_exit("Max 2 arguments\n"); - } - - if ((toys.optflags & FLAG_a) && dir) error_exit("-a with >1 arg"); - - // For remount we need _last_ match (in case of overmounts), so traverse - // in reverse order. - if (comma_scan(opts, "remount", 1)) - remount = dlist_terminate(mtl = xgetmountlist("/proc/mounts")); - - // Do we need to do an /etc/fstab trawl? - // This covers -a, -o remount, one argument, all user mounts - if ((toys.optflags & FLAG_a) || (dev && (!dir || getuid() || remount))) { - if (!remount) mtl = xgetmountlist("/etc/fstab"); - - for (mm = remount ? remount : mtl; mm; mm = (remount ? mm->prev : mm->next)) - { - int aflags, noauto, len; - char *aopts = 0; - - // Check for noauto and get it out of the option list. (Unknown options - // that make it to the kernel give filesystem drivers indigestion.) - noauto = comma_scan(mm->opts, "noauto", 1); - if (toys.optflags & FLAG_a) { - // "mount -a /path" to mount all entries under /path - if (dev) { - len = strlen(dev); - if (strncmp(dev, mm->dir, len) - || (mm->dir[len] && mm->dir[len] != '/')) continue; - } else if (noauto) continue; // never present in the remount case - if (!mountlist_istype(mm,TT.type) || !comma_scanall(mm->opts,TT.bigO)) - continue; - } else { - if (dir && strcmp(dir, mm->dir)) continue; - if (dev && strcmp(dev, mm->device) && (dir || strcmp(dev, mm->dir))) - continue; - } - - // user only counts from fstab, not opts. - TT.okuser = comma_scan(mm->opts, "user", 1); - aflags = flag_opts(mm->opts, flags, &aopts); - aflags = flag_opts(opts, aflags, &aopts); - - mount_filesystem(mm->device, mm->dir, mm->type, aflags, aopts); - free(aopts); - - if (!(toys.optflags & FLAG_a)) break; - } - if (CFG_TOYBOX_FREE) llist_traverse(mtl, free); - - // show mounts from /proc/mounts - } else if (!dev) { - for (mtl = xgetmountlist(0); mtl && (mm = dlist_pop(&mtl)); free(mm)) { - char *s = 0; - - if (TT.type && strcmp(TT.type, mm->type)) continue; - if (*mm->device == '/') s = xabspath(mm->device, 0); - xprintf("%s on %s type %s (%s)\n", - s ? s : mm->device, mm->dir, mm->type, mm->opts); - free(s); - } - - // two arguments - } else { - char *more = 0; - - mount_filesystem(dev, dir, TT.type, flag_opts(opts, flags, &more), more); - if (CFG_TOYBOX_FREE) free(more); - } -}