Currently, kernel and FUSE mounts are supported for local images.
Support for remote images will be added later.
Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
v2:
- fix missing <fcntl.h>
Makefile.am | 2 +-
configure.ac | 2 +
include/erofs/err.h | 10 ++
include/erofs/internal.h | 11 --
mount/Makefile.am | 11 ++
mount/main.c | 289 +++++++++++++++++++++++++++++++++++++++
6 files changed, 313 insertions(+), 12 deletions(-)
create mode 100644 mount/Makefile.am
create mode 100644 mount/main.c
diff --git a/Makefile.am b/Makefile.am
index f8a967f..7cb93a6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -6,4 +6,4 @@ SUBDIRS = man lib mkfs dump fsck
if ENABLE_FUSE
SUBDIRS += fuse
endif
-SUBDIRS += contrib
+SUBDIRS += mount contrib
diff --git a/configure.ac b/configure.ac
index 1efb57a..c0174ce 100644
--- a/configure.ac
+++ b/configure.ac
@@ -217,6 +217,7 @@ AC_CHECK_HEADERS(m4_flatten([
linux/aufs_type.h
linux/falloc.h
linux/fs.h
+ linux/loop.h
linux/types.h
linux/xattr.h
limits.h
@@ -799,5 +800,6 @@ AC_CONFIG_FILES([Makefile
dump/Makefile
fuse/Makefile
fsck/Makefile
+ mount/Makefile
contrib/Makefile])
AC_OUTPUT
diff --git a/include/erofs/err.h b/include/erofs/err.h
index 2ae9e21..ff488dd 100644
--- a/include/erofs/err.h
+++ b/include/erofs/err.h
@@ -13,6 +13,16 @@ extern "C"
#endif
#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+static inline const char *erofs_strerror(int err)
+{
+ static char msg[256];
+
+ sprintf(msg, "[Error %d] %s", -err, strerror(-err));
+ return msg;
+}
#define MAX_ERRNO (4095)
#define IS_ERR_VALUE(x)
\
diff --git a/include/erofs/internal.h b/include/erofs/internal.h
index ea58584..9a82e06 100644
--- a/include/erofs/internal.h
+++ b/include/erofs/internal.h
@@ -362,17 +362,6 @@ static inline bool is_dot_dotdot(const char *name)
return name[1] == '\0' || (name[1] == '.' && name[2] == '\0');
}
-#include <stdio.h>
-#include <string.h>
-
-static inline const char *erofs_strerror(int err)
-{
- static char msg[256];
-
- sprintf(msg, "[Error %d] %s", -err, strerror(-err));
- return msg;
-}
-
enum {
BH_Meta,
BH_Mapped,
diff --git a/mount/Makefile.am b/mount/Makefile.am
new file mode 100644
index 0000000..d901c20
--- /dev/null
+++ b/mount/Makefile.am
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Makefile.am
+
+AUTOMAKE_OPTIONS = foreign
+sbin_PROGRAMS = mount.erofs
+AM_CPPFLAGS = ${libuuid_CFLAGS}
+mount_erofs_SOURCES = main.c
+mount_erofs_CFLAGS = -Wall -I$(top_srcdir)/include
+mount_erofs_LDADD = $(top_builddir)/lib/liberofs.la ${libselinux_LIBS} \
+ ${liblz4_LIBS} ${liblzma_LIBS} ${zlib_LIBS} ${libdeflate_LIBS} \
+ ${libzstd_LIBS} ${libqpl_LIBS} ${libxxhash_LIBS}
diff --git a/mount/main.c b/mount/main.c
new file mode 100644
index 0000000..0f7538a
--- /dev/null
+++ b/mount/main.c
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: GPL-2.0+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <unistd.h>
+#include "erofs/config.h"
+#include "erofs/print.h"
+#include "erofs/err.h"
+#ifdef HAVE_LINUX_LOOP_H
+#include <linux/loop.h>
+#else
+#define LOOP_CTL_GET_FREE 0x4C82
+#define LOOP_SET_FD 0x4C00
+#define LOOP_SET_STATUS 0x4C02
+enum {
+ LO_FLAGS_AUTOCLEAR = 4,
+};
+struct loop_info {
+ char pad[44];
+ int lo_flags;
+ char pad1[120];
+};
+#endif
+
+enum erofs_backend_drv {
+ EROFSAUTO,
+ EROFSLOCAL,
+ EROFSFUSE,
+};
+
+static struct erofsmount_cfg {
+ char *device;
+ char *mountpoint;
+ char *options;
+ char *full_options; /* used for erofsfuse */
+ char *fstype;
+ long flags;
+ enum erofs_backend_drv backend;
+} mountcfg = {
+ .full_options = "ro",
+ .flags = MS_RDONLY, /* default mountflags */
+ .fstype = "erofs",
+};
+
+static long erofsmount_parse_flagopts(char *s, long flags, char **more)
+{
+ static const struct {
+ char *name;
+ long flags;
+ } opts[] = {
+ {"defaults", 0}, {"quiet", 0}, // NOPs
+ {"user", 0}, {"nouser", 0}, // checked in fstab, ignored in -o
+ {"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},
+ {"norelatime", ~MS_RELATIME}, {"relatime", MS_RELATIME},
+ {"nodiratime", MS_NODIRATIME}, {"diratime", ~MS_NODIRATIME},
+ {"loud", ~MS_SILENT},
+ {"remount", MS_REMOUNT}, {"move", MS_MOVE},
+ // mand dirsync rec iversion strictatime
+ };
+
+ for (;;) {
+ char *comma;
+ int i;
+
+ comma = strchr(s, ',');
+ if (comma)
+ *comma = '\0';
+ for (i = 0; i < ARRAY_SIZE(opts); ++i) {
+ if (!strcasecmp(s, opts[i].name)) {
+ if (opts[i].flags < 0)
+ flags &= opts[i].flags;
+ else
+ flags |= opts[i].flags;
+ break;
+ }
+ }
+
+ if (more && i >= ARRAY_SIZE(opts)) {
+ int sl = strlen(s);
+ char *new = *more;
+
+ i = new ? strlen(new) : 0;
+ new = realloc(new, i + strlen(s) + 2);
+ if (!new)
+ return -ENOMEM;
+ if (i)
+ new[i++] = ',';
+ memcpy(new + i, s, sl);
+ new[i + sl] = '\0';
+ *more = new;
+ }
+
+ if (!comma)
+ break;
+ *comma = ',';
+ s = comma + 1;
+ }
+ return flags;
+}
+
+static int erofsmount_parse_options(int argc, char **argv)
+{
+ static const struct option long_options[] = {
+ {"help", no_argument, 0, 'h'},
+ {0, 0, 0, 0},
+ };
+ char *dot;
+ int opt;
+
+ while ((opt = getopt_long(argc, argv, "Nfno:st:v",
+ long_options, NULL)) != -1) {
+ switch (opt) {
+ case 'o':
+ mountcfg.full_options = optarg;
+ mountcfg.flags =
+ erofsmount_parse_flagopts(optarg,
mountcfg.flags,
+ &mountcfg.options);
+ break;
+ case 't':
+ dot = strchr(optarg, '.');
+ if (dot) {
+ if (!strcmp(dot + 1, "fuse")) {
+ mountcfg.backend = EROFSFUSE;
+ } else if (!strcmp(dot + 1, "local")) {
+ mountcfg.backend = EROFSLOCAL;
+ } else {
+ erofs_err("invalid filesystem subtype
`%s`", dot + 1);
+ return -EINVAL;
+ }
+ *dot = '\0';
+ }
+ mountcfg.fstype = optarg;
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+
+ if (optind >= argc) {
+ erofs_err("missing argument: DEVICE");
+ return -EINVAL;
+ }
+
+ mountcfg.device = strdup(argv[optind++]);
+ if (!mountcfg.device)
+ return -ENOMEM;
+
+ if (optind >= argc) {
+ erofs_err("missing argument: MOUNTPOINT");
+ return -EINVAL;
+ }
+
+ mountcfg.mountpoint = strdup(argv[optind++]);
+ if (!mountcfg.mountpoint)
+ return -ENOMEM;
+
+ if (optind < argc) {
+ erofs_err("unexpected argument: %s\n", argv[optind]);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int erofsmount_fuse(const char *source, const char *mountpoint,
+ const char *fstype, const char *options)
+{
+ char *command;
+ int err;
+
+ if (strcmp(fstype, "erofs")) {
+ fprintf(stderr, "unsupported filesystem type `%s`\n",
+ mountcfg.fstype);
+ return -ENODEV;
+ }
+
+ err = asprintf(&command, "erofsfuse -o%s %s %s", options,
+ source, mountpoint);
+ if (err < 0)
+ return -ENOMEM;
+
+ /* execvp() doesn't work for external mount helpers here */
+ err = execl("/bin/sh", "/bin/sh", "-c", command, NULL);
+ if (err < 0) {
+ perror("failed to execute /bin/sh");
+ return -errno;
+ }
+ return 0;
+}
+
+#define EROFSMOUNT_LOOPDEV_RETRIES 3
+
+int erofsmount_loopmount(const char *source, const char *mountpoint,
+ const char *fstype, int flags,
+ const char *options)
+{
+ int fd, dfd, num;
+ struct loop_info li = {};
+ bool ro = flags & MS_RDONLY;
+ char device[32];
+
+ fd = open("/dev/loop-control", O_RDWR | O_CLOEXEC);
+ if (fd < 0)
+ return -errno;
+
+ num = ioctl(fd, LOOP_CTL_GET_FREE);
+ if (num < 0)
+ return -errno;
+ close(fd);
+
+ snprintf(device, sizeof(device), "/dev/loop%d", num);
+ for (num = 0; num < EROFSMOUNT_LOOPDEV_RETRIES; ++num) {
+ fd = open(device, (ro ? O_RDONLY : O_RDWR) | O_CLOEXEC);
+ if (fd >= 0)
+ break;
+ usleep(50000);
+ }
+ if (fd < 0)
+ return -errno;
+
+ dfd = open(source, (ro ? O_RDONLY : O_RDWR));
+ if (dfd < 0)
+ goto out_err;
+
+ num = ioctl(fd, LOOP_SET_FD, dfd);
+ if (num < 0) {
+ close(dfd);
+ goto out_err;
+ }
+ close(dfd);
+
+ li.lo_flags = LO_FLAGS_AUTOCLEAR;
+ num = ioctl(fd, LOOP_SET_STATUS, &li);
+ if (num < 0)
+ goto out_err;
+ num = mount(device, mountpoint, fstype, flags, options);
+ if (num < 0)
+ goto out_err;
+ close(fd);
+ return 0;
+out_err:
+ close(fd);
+ return -errno;
+}
+
+int main(int argc, char *argv[])
+{
+ int err;
+
+ erofs_init_configure();
+ err = erofsmount_parse_options(argc, argv);
+ if (err) {
+ if (err == -EINVAL)
+ fprintf(stderr, "Try '%s --help' for more
information.\n", argv[0]);
+ return EXIT_FAILURE;
+ }
+
+ if (mountcfg.backend == EROFSFUSE) {
+ err = erofsmount_fuse(mountcfg.device, mountcfg.mountpoint,
+ mountcfg.fstype, mountcfg.full_options);
+ goto exit;
+ }
+
+ err = mount(mountcfg.device, mountcfg.mountpoint, mountcfg.fstype,
+ mountcfg.flags, mountcfg.options);
+ if (err < 0)
+ err = -errno;
+
+ if ((err == -ENODEV || err == -EPERM) && mountcfg.backend == EROFSAUTO)
+ err = erofsmount_fuse(mountcfg.device, mountcfg.mountpoint,
+ mountcfg.fstype, mountcfg.full_options);
+ else if (err == -ENOTBLK)
+ err = erofsmount_loopmount(mountcfg.device, mountcfg.mountpoint,
+ mountcfg.fstype, mountcfg.flags,
+ mountcfg.options);
+exit:
+ if (err < 0)
+ fprintf(stderr, "Failed to mount %s: %s\n",
+ mountcfg.fstype, erofs_strerror(err));
+ return err ? EXIT_FAILURE : EXIT_SUCCESS;
+}
--
2.43.5
