* [RFC PATCH v2 1/4] btrfs-progs: Makefile: create separated binaries for "btrfs" subcommands; add fscaps declarations
2018-09-12 14:46 [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands Axel Burri
@ 2018-09-12 14:46 ` Axel Burri
2018-09-12 14:46 ` [RFC PATCH v2 2/4] btrfs-progs: remove unneeded dependencies on separated build (-DBTRFS_SEPARATED_BUILD) Axel Burri
` (3 subsequent siblings)
4 siblings, 0 replies; 9+ messages in thread
From: Axel Burri @ 2018-09-12 14:46 UTC (permalink / raw)
To: linux-btrfs; +Cc: Axel Burri
Create separate binaries "btrfs-xxx-yyy.separated" for each subcommand
"btrfs xxx yyy". Also declares fscaps for (supported) subcommands.
This is useful for admins to provide specific subcommand binaries with
elevated privileges (capabilities(7), suid).
Example:
# make separated-fscaps
# make list-fscaps
# ./btrfs-subvolume-list.separated
# ./btrfs-send.separated
<...>
# make -k separated
A list of subcommands is assembled in the makefile by matching main
entry points and generic "@SEPARATED" tags in "cmds-*.c", e.g.:
// @SEPARATED btrfs-subvolume-delete fscaps: cap_sys_admin,cap_dac_override
static int cmd_subvol_delete(int argc, char **argv)
A patch in "commands.h" adds a "int main()" symbol and tweaks for
building separated binaries if BTRFS_SEPARATED_BUILD and
BTRFS_SEPARATED_ENTRY are defined. These defines are set generically
for each subcommand in the "btrfs-%.separated.o" makefile target.
Makefile targets:
- "btrfs-%.separated": builds a separated binary for a specific btrfs
subcommand (see "make list-separated").
- `make -k separated`: builds all separated (btrfs-xxx-yyy.separated)
binaries. Note: some targets fail with "ld: undefined reference"
errors (will be fixed in later commit).
- `make separated-fscaps`: build separated binaries for subcommands
declaring "@SEPARATED btrfs-xxx fscaps" (comments) within the
c-file (for sysadmins / package maintainer).
- `make list-separated`: print a list of supported subcommands.
- `make list-fscaps`: print fscaps required for setcap(8). Note that
this list only covers some basic subcommands (the ones used by
btrbk-0.26.1 "backend btrfs-progs-btrbk") and needs to be improved.
Signed-off-by: Axel Burri <axel@tty0.ch>
---
.gitignore | 1 +
Makefile | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
cmds-fi-usage.c | 1 +
cmds-qgroup.c | 1 +
cmds-receive.c | 1 +
cmds-send.c | 1 +
cmds-subvolume.c | 4 ++++
commands.h | 45 +++++++++++++++++++++++++++++++++++++++++++++
8 files changed, 107 insertions(+)
diff --git a/.gitignore b/.gitignore
index 144ebb3b..e1eb1341 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,7 @@ Documentation/*.gz
Documentation/*.html
btrfs
btrfs.static
+btrfs-*.separated
btrfs-map-logical
btrfs-fragments
btrfsck
diff --git a/Makefile b/Makefile
index fcfc815a..35666ec9 100644
--- a/Makefile
+++ b/Makefile
@@ -2,6 +2,7 @@
# Basic build targets:
# all all main tools and the shared library
# static build static bnaries, requires static version of the libraries
+# separated build separated binary for each "btrfs" subcommand
# test run the full testsuite
# install install to default location (/usr/local)
# clean clean built binaries (not the documentation)
@@ -231,6 +232,27 @@ progs_install =
progs_build =
endif
+# Parse "int cmd_xxx_yyy(int argc, char **argv)" lines in cfiles, and
+# create whitespace separated map of form: "btrfs-xxx-yyy@key:value".
+sc_cfiles := $(wildcard cmds-*.c)
+sc_map := $(foreach file,$(sc_cfiles),$(shell sed -rn 's/^(static )?int cmd_([a-z_]+)\(int argc, char.*argv.*\)$$/btrfs_\2@cfile:$(file) btrfs_\2@entry:cmd_\2 btrfs_\2@static_entry:\1/p' $(file)))
+sc_map := $(foreach val,$(sc_map),$(subst _,-,$(firstword $(subst @, ,$(val))))@$(word 2,$(subst @, ,$(val))))
+sc_map := $(subst btrfs-subvol-,btrfs-subvolume-,$(sc_map))
+
+# Parse generic "@SEPARATED btrfs-xxx-yyy key: value" in cfiles, and add to map.
+sc_map += $(shell sed -rn 's/^.*@SEPARATED\s+(btrfs-[a-z-]+)\s+([a-z_]+):\s*(.*)$$/\1@\2:\3/p' $(sc_cfiles))
+sc_get = $(word 2,$(subst :, ,$(filter $(1)@$(2):%,$(sc_map))))
+
+# Exclude first-level commands relying on "int handle_command_group()" or buggy
+sc_exclude = btrfs-balance btrfs-balance-full btrfs-device btrfs-filesystem btrfs-inspect btrfs-property btrfs-qgroup btrfs-quota btrfs-replace btrfs-rescue btrfs-scrub btrfs-subvolume
+sc_cmds_all := $(sort $(foreach val,$(sc_map),$(firstword $(subst @, ,$(val)))))
+sc_cmds := $(filter-out $(sc_exclude),$(sc_cmds_all))
+sc_cmds_fscaps := $(sort $(subst @fscaps,,$(filter %@fscaps,$(subst :, ,$(sc_map)))))
+
+# Using suffix allows strict distinction in targets below (btrfs-%.separated[.o])
+progs_separated = $(addsuffix .separated,$(sc_cmds))
+progs_separated_fscaps = $(addsuffix .separated,$(sc_cmds_fscaps))
+
# external libs required by various binaries; for btrfs-foo,
# specify btrfs_foo_libs = <list of libs>; see $($(subst...)) rules below
btrfs_convert_cflags = -DBTRFSCONVERT_EXT2=$(BTRFSCONVERT_EXT2)
@@ -312,6 +334,17 @@ endif
$(Q)$(CC) $(CFLAGS) -c $< -o $@ $($(subst -,_,$(@:%.o=%)-cflags)) \
$($(subst -,_,btrfs-$(@:%/$(notdir $@)=%)-cflags))
+# Compile target objects providing main() symbol (see commands.h:
+# BTRFS_SEPARATED_BUILD), using "cfile" from sc_map (cmd-xxx.c) as gcc infile.
+btrfs-%.separated.o: $(call sc_get,$(@:%.separated.o=%),cfile)
+ @echo " [CC] $@"
+ $(Q)$(CC) $(CFLAGS) \
+ -DBTRFS_SEPARATED_BUILD \
+ -DBTRFS_SEPARATED_ENTRY=$(call sc_get,$(@:%.separated.o=%),entry) \
+ -DBTRFS_SEPARATED_USAGE=$(call sc_get,$(@:%.separated.o=%),entry)_usage \
+ $(if $(call sc_get,$(@:%.separated.o=%),static_entry),-DBTRFS_SEPARATED_STATIC_ENTRY) \
+ -c $(call sc_get,$(@:%.separated.o=%),cfile) -o $@
+
%.static.o: %.c
@echo " [CC] $@"
$(Q)$(CC) $(STATIC_CFLAGS) -c $< -o $@ $($(subst -,_,$(@:%.static.o=%)-cflags)) \
@@ -384,6 +417,20 @@ endif
#
static: $(progs_static)
+separated: $(progs_separated)
+
+separated-fscaps: $(progs_separated_fscaps)
+
+.PHONY: separated separated-fscaps
+
+list-separated:
+ @echo "$(sc_cmds)" | tr ' ' '\n'
+
+list-fscaps:
+ @echo "$(foreach sc,$(sc_cmds_fscaps),$(sc)=$(call sc_get,$(sc),fscaps))" | tr ' ' '\n'
+
+.PHONY: list-separated list-fscaps
+
version.h: version.h.in configure.ac
@echo " [SH] $@"
$(Q)bash ./config.status --silent $@
@@ -454,6 +501,11 @@ btrfs-%.static: btrfs-%.static.o $(static_objects) $(patsubst %.o,%.static.o,$(s
$(static_libbtrfs_objects) $(STATIC_LDFLAGS) \
$($(subst -,_,$(subst .static,,$@)-libs)) $(STATIC_LIBS)
+btrfs-%.separated: btrfs-%.separated.o $(objects) $(cmds_objects) $(libs_static)
+ @echo " [LD] $@"
+ $(Q)$(CC) -o $@ $@.o $(objects) $(libs_static) \
+ $(LDFLAGS) $(LIBS)
+
btrfs-%: btrfs-%.o $(objects) $(standalone_deps) $(libs_static)
@echo " [LD] $@"
$(Q)$(CC) -o $@ $(objects) $@.o \
@@ -618,6 +670,7 @@ clean: $(CLEANDIRS)
$(check_defs) \
$(libs) $(lib_links) \
$(progs_static) \
+ $(progs_separated) \
libbtrfsutil/*.o libbtrfsutil/*.o.d
ifeq ($(PYTHON_BINDINGS),1)
$(Q)cd libbtrfsutil/python; \
diff --git a/cmds-fi-usage.c b/cmds-fi-usage.c
index dca2e8d0..f44dfe54 100644
--- a/cmds-fi-usage.c
+++ b/cmds-fi-usage.c
@@ -964,6 +964,7 @@ const char * const cmd_filesystem_usage_usage[] = {
NULL
};
+// @SEPARATED btrfs-filesystem-usage fscaps: cap_sys_admin
int cmd_filesystem_usage(int argc, char **argv)
{
int ret = 0;
diff --git a/cmds-qgroup.c b/cmds-qgroup.c
index b928edc7..554f2bf2 100644
--- a/cmds-qgroup.c
+++ b/cmds-qgroup.c
@@ -259,6 +259,7 @@ static const char * const cmd_qgroup_destroy_usage[] = {
NULL
};
+// @SEPARATED btrfs-qgroup-destroy fscaps: cap_sys_admin,cap_dac_override
static int cmd_qgroup_destroy(int argc, char **argv)
{
int ret;
diff --git a/cmds-receive.c b/cmds-receive.c
index 34d51ef3..04aaad6c 100644
--- a/cmds-receive.c
+++ b/cmds-receive.c
@@ -1248,6 +1248,7 @@ out:
return ret;
}
+// @SEPARATED btrfs-receive fscaps: cap_sys_admin,cap_fowner,cap_chown,cap_mknod,cap_setfcap,cap_dac_override,cap_dac_read_search
int cmd_receive(int argc, char **argv)
{
char *tomnt = NULL;
diff --git a/cmds-send.c b/cmds-send.c
index 16b9f8d2..259faeff 100644
--- a/cmds-send.c
+++ b/cmds-send.c
@@ -489,6 +489,7 @@ static void free_send_info(struct btrfs_send *sctx)
subvol_uuid_search_finit(&sctx->sus);
}
+// @SEPARATED btrfs-send fscaps: cap_sys_admin,cap_fowner,cap_dac_read_search
int cmd_send(int argc, char **argv)
{
char *subvol = NULL;
diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index e7a884af..a4202ec9 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -231,6 +231,7 @@ static const char * const cmd_subvol_delete_usage[] = {
NULL
};
+// @SEPARATED btrfs-subvolume-delete fscaps: cap_sys_admin,cap_dac_override
static int cmd_subvol_delete(int argc, char **argv)
{
int res, ret = 0;
@@ -451,6 +452,7 @@ static const char * const cmd_subvol_list_usage[] = {
NULL,
};
+// @SEPARATED btrfs-subvolume-list fscaps: cap_sys_admin,cap_fowner,cap_dac_read_search
static int cmd_subvol_list(int argc, char **argv)
{
struct btrfs_list_filter_set *filter_set;
@@ -623,6 +625,7 @@ static const char * const cmd_subvol_snapshot_usage[] = {
NULL
};
+// @SEPARATED btrfs-subvolume-snapshot fscaps: cap_sys_admin,cap_fowner,cap_dac_override,cap_dac_read_search
static int cmd_subvol_snapshot(int argc, char **argv)
{
char *subvol, *dst;
@@ -920,6 +923,7 @@ static const char * const cmd_subvol_show_usage[] = {
NULL
};
+// @SEPARATED btrfs-subvolume-show fscaps: cap_sys_admin,cap_fowner,cap_dac_read_search
static int cmd_subvol_show(int argc, char **argv)
{
char tstr[256];
diff --git a/commands.h b/commands.h
index 76991f2b..c9901de9 100644
--- a/commands.h
+++ b/commands.h
@@ -121,4 +121,49 @@ int cmd_dump_super(int argc, char **argv);
int cmd_debug_tree(int argc, char **argv);
int cmd_rescue(int argc, char **argv);
+
+#ifdef BTRFS_SEPARATED_BUILD
+
+#ifndef BTRFS_SEPARATED_ENTRY
+#error please define BTRFS_SEPARATED_ENTRY (see Makefile: "btrfs-%.separated.o" target)
+#endif
+
+#ifdef BTRFS_SEPARATED_USAGE
+#include "help.h"
+#endif
+
+/* Note: handle_command_group is defined in btrfs.c and cannot be
+ * linked with separated subcommands because btrfs.o also contains a
+ * "main" symbol. As a workaround, we simply return 1 (error) for
+ * calls to handle_command_group() here (which is fine as this
+ * functionality is not required for BTRFS_SEPARATED_BUILD commands).
+ */
+#define handle_command_group(cmd_group,argc,argv) 1
+
+/* forward declaration of main entry point (non-static are already declared above) */
+#ifdef BTRFS_SEPARATED_STATIC_ENTRY
+static int BTRFS_SEPARATED_ENTRY(int argc, char **argv);
+static const char * const BTRFS_SEPARATED_USAGE [];
+#endif
+
+int main(int argc, char **argv)
+{
+ int i;
+ for (i = 1; i < argc; i++) {
+#ifdef BTRFS_SEPARATED_USAGE
+ if (strcmp(argv[i], "--help") == 0) {
+ usage(BTRFS_SEPARATED_USAGE);
+ return 0;
+ }
+#endif
+ if (strcmp(argv[i], "--version") == 0) {
+ printf("%s\n", PACKAGE_STRING);
+ return 0;
+ }
+ }
+ return BTRFS_SEPARATED_ENTRY (argc, argv);
+}
+
+#endif /* BTRFS_SEPARATED_BUILD */
+
#endif
--
2.16.4
^ permalink raw reply related [flat|nested] 9+ messages in thread* [RFC PATCH v2 2/4] btrfs-progs: remove unneeded dependencies on separated build (-DBTRFS_SEPARATED_BUILD)
2018-09-12 14:46 [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands Axel Burri
2018-09-12 14:46 ` [RFC PATCH v2 1/4] btrfs-progs: Makefile: create separated binaries for "btrfs" subcommands; add fscaps declarations Axel Burri
@ 2018-09-12 14:46 ` Axel Burri
2018-09-12 14:46 ` [RFC PATCH v2 3/4] btrfs-progs: Makefile: add extra objects definitions for separated binaries Axel Burri
` (2 subsequent siblings)
4 siblings, 0 replies; 9+ messages in thread
From: Axel Burri @ 2018-09-12 14:46 UTC (permalink / raw)
To: linux-btrfs; +Cc: Axel Burri
Remove references to unneeded symbols when building separated
subcommands: "btrfs-*.separated.o".
Note that this patch still leaves unreferenced static symbols, which
in turn makes the compiler warn about "unused function/variable".
Stripping all symbols would imply adaptions in the source code
(especially by moving "int handle_command_group" functionality into a
separate compile unit).
This is not a problem, ignore these warnings when building object:
$(CC) -Wno-unused-function -Wno-unused-const-variable
Signed-off-by: Axel Burri <axel@tty0.ch>
---
Makefile | 2 +-
cmds-balance.c | 2 ++
cmds-device.c | 2 ++
cmds-filesystem.c | 2 ++
cmds-inspect.c | 2 ++
cmds-property.c | 2 ++
cmds-qgroup.c | 2 ++
cmds-quota.c | 2 ++
cmds-replace.c | 2 ++
cmds-rescue.c | 2 ++
cmds-scrub.c | 2 ++
cmds-subvolume.c | 2 ++
commands.h | 8 --------
13 files changed, 23 insertions(+), 9 deletions(-)
diff --git a/Makefile b/Makefile
index 35666ec9..95db571b 100644
--- a/Makefile
+++ b/Makefile
@@ -338,7 +338,7 @@ endif
# BTRFS_SEPARATED_BUILD), using "cfile" from sc_map (cmd-xxx.c) as gcc infile.
btrfs-%.separated.o: $(call sc_get,$(@:%.separated.o=%),cfile)
@echo " [CC] $@"
- $(Q)$(CC) $(CFLAGS) \
+ $(Q)$(CC) $(CFLAGS) -Wno-unused-function -Wno-unused-const-variable \
-DBTRFS_SEPARATED_BUILD \
-DBTRFS_SEPARATED_ENTRY=$(call sc_get,$(@:%.separated.o=%),entry) \
-DBTRFS_SEPARATED_USAGE=$(call sc_get,$(@:%.separated.o=%),entry)_usage \
diff --git a/cmds-balance.c b/cmds-balance.c
index 6cc26c35..72292bc8 100644
--- a/cmds-balance.c
+++ b/cmds-balance.c
@@ -914,6 +914,7 @@ static int cmd_balance_full(int argc, char **argv)
static const char balance_cmd_group_info[] =
"balance data across devices, or change block groups using filters";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group balance_cmd_group = {
balance_cmd_group_usage, balance_cmd_group_info, {
{ "start", cmd_balance_start, cmd_balance_start_usage, NULL, 0 },
@@ -940,3 +941,4 @@ int cmd_balance(int argc, char **argv)
return handle_command_group(&balance_cmd_group, argc, argv);
}
+#endif
diff --git a/cmds-device.c b/cmds-device.c
index 2a05f70a..719afc01 100644
--- a/cmds-device.c
+++ b/cmds-device.c
@@ -597,6 +597,7 @@ static int cmd_device_usage(int argc, char **argv)
static const char device_cmd_group_info[] =
"manage and query devices in the filesystem";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group device_cmd_group = {
device_cmd_group_usage, device_cmd_group_info, {
{ "add", cmd_device_add, cmd_device_add_usage, NULL, 0 },
@@ -616,3 +617,4 @@ int cmd_device(int argc, char **argv)
{
return handle_command_group(&device_cmd_group, argc, argv);
}
+#endif
diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index 06c8311b..be5d50f2 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -1182,6 +1182,7 @@ static int cmd_filesystem_label(int argc, char **argv)
static const char filesystem_cmd_group_info[] =
"overall filesystem tasks and information";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group filesystem_cmd_group = {
filesystem_cmd_group_usage, filesystem_cmd_group_info, {
{ "df", cmd_filesystem_df, cmd_filesystem_df_usage, NULL, 0 },
@@ -1209,3 +1210,4 @@ int cmd_filesystem(int argc, char **argv)
{
return handle_command_group(&filesystem_cmd_group, argc, argv);
}
+#endif
diff --git a/cmds-inspect.c b/cmds-inspect.c
index ac77a5ee..1ad48548 100644
--- a/cmds-inspect.c
+++ b/cmds-inspect.c
@@ -634,6 +634,7 @@ out:
static const char inspect_cmd_group_info[] =
"query various internal information";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group inspect_cmd_group = {
inspect_cmd_group_usage, inspect_cmd_group_info, {
{ "inode-resolve", cmd_inspect_inode_resolve,
@@ -660,3 +661,4 @@ int cmd_inspect(int argc, char **argv)
{
return handle_command_group(&inspect_cmd_group, argc, argv);
}
+#endif
diff --git a/cmds-property.c b/cmds-property.c
index 03bafa05..c98e8ebb 100644
--- a/cmds-property.c
+++ b/cmds-property.c
@@ -408,6 +408,7 @@ static int cmd_property_list(int argc, char **argv)
static const char property_cmd_group_info[] =
"modify properties of filesystem objects";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group property_cmd_group = {
property_cmd_group_usage, property_cmd_group_info, {
{ "get", cmd_property_get,
@@ -424,3 +425,4 @@ int cmd_property(int argc, char **argv)
{
return handle_command_group(&property_cmd_group, argc, argv);
}
+#endif
diff --git a/cmds-qgroup.c b/cmds-qgroup.c
index 554f2bf2..5f5a3563 100644
--- a/cmds-qgroup.c
+++ b/cmds-qgroup.c
@@ -503,6 +503,7 @@ static int cmd_qgroup_limit(int argc, char **argv)
static const char qgroup_cmd_group_info[] =
"manage quota groups";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group qgroup_cmd_group = {
qgroup_cmd_group_usage, qgroup_cmd_group_info, {
{ "assign", cmd_qgroup_assign, cmd_qgroup_assign_usage,
@@ -525,3 +526,4 @@ int cmd_qgroup(int argc, char **argv)
{
return handle_command_group(&qgroup_cmd_group, argc, argv);
}
+#endif
diff --git a/cmds-quota.c b/cmds-quota.c
index c9ea9c0f..8585d427 100644
--- a/cmds-quota.c
+++ b/cmds-quota.c
@@ -194,6 +194,7 @@ static int cmd_quota_rescan(int argc, char **argv)
static const char quota_cmd_group_info[] =
"manage filesystem quota settings";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group quota_cmd_group = {
quota_cmd_group_usage, quota_cmd_group_info, {
{ "enable", cmd_quota_enable, cmd_quota_enable_usage, NULL, 0 },
@@ -208,3 +209,4 @@ int cmd_quota(int argc, char **argv)
{
return handle_command_group("a_cmd_group, argc, argv);
}
+#endif
diff --git a/cmds-replace.c b/cmds-replace.c
index 1fa80284..44456c4a 100644
--- a/cmds-replace.c
+++ b/cmds-replace.c
@@ -545,6 +545,7 @@ static int cmd_replace_cancel(int argc, char **argv)
static const char replace_cmd_group_info[] =
"replace a device in the filesystem";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group replace_cmd_group = {
replace_cmd_group_usage, replace_cmd_group_info, {
{ "start", cmd_replace_start, cmd_replace_start_usage, NULL,
@@ -561,3 +562,4 @@ int cmd_replace(int argc, char **argv)
{
return handle_command_group(&replace_cmd_group, argc, argv);
}
+#endif
diff --git a/cmds-rescue.c b/cmds-rescue.c
index 38c4ab9b..bdc6dd4b 100644
--- a/cmds-rescue.c
+++ b/cmds-rescue.c
@@ -253,6 +253,7 @@ out:
static const char rescue_cmd_group_info[] =
"toolbox for specific rescue operations";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group rescue_cmd_group = {
rescue_cmd_group_usage, rescue_cmd_group_info, {
{ "chunk-recover", cmd_rescue_chunk_recover,
@@ -270,3 +271,4 @@ int cmd_rescue(int argc, char **argv)
{
return handle_command_group(&rescue_cmd_group, argc, argv);
}
+#endif
diff --git a/cmds-scrub.c b/cmds-scrub.c
index 6b909f20..e418f907 100644
--- a/cmds-scrub.c
+++ b/cmds-scrub.c
@@ -1788,6 +1788,7 @@ out:
static const char scrub_cmd_group_info[] =
"verify checksums of data and metadata";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group scrub_cmd_group = {
scrub_cmd_group_usage, scrub_cmd_group_info, {
{ "start", cmd_scrub_start, cmd_scrub_start_usage, NULL, 0 },
@@ -1802,3 +1803,4 @@ int cmd_scrub(int argc, char **argv)
{
return handle_command_group(&scrub_cmd_group, argc, argv);
}
+#endif
diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index a4202ec9..15dbdf3a 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -1226,6 +1226,7 @@ out:
static const char subvolume_cmd_group_info[] =
"manage subvolumes: create, delete, list, etc";
+#ifndef BTRFS_SEPARATED_BUILD
const struct cmd_group subvolume_cmd_group = {
subvolume_cmd_group_usage, subvolume_cmd_group_info, {
{ "create", cmd_subvol_create, cmd_subvol_create_usage, NULL, 0 },
@@ -1249,3 +1250,4 @@ int cmd_subvolume(int argc, char **argv)
{
return handle_command_group(&subvolume_cmd_group, argc, argv);
}
+#endif
diff --git a/commands.h b/commands.h
index c9901de9..35081b94 100644
--- a/commands.h
+++ b/commands.h
@@ -132,14 +132,6 @@ int cmd_rescue(int argc, char **argv);
#include "help.h"
#endif
-/* Note: handle_command_group is defined in btrfs.c and cannot be
- * linked with separated subcommands because btrfs.o also contains a
- * "main" symbol. As a workaround, we simply return 1 (error) for
- * calls to handle_command_group() here (which is fine as this
- * functionality is not required for BTRFS_SEPARATED_BUILD commands).
- */
-#define handle_command_group(cmd_group,argc,argv) 1
-
/* forward declaration of main entry point (non-static are already declared above) */
#ifdef BTRFS_SEPARATED_STATIC_ENTRY
static int BTRFS_SEPARATED_ENTRY(int argc, char **argv);
--
2.16.4
^ permalink raw reply related [flat|nested] 9+ messages in thread* [RFC PATCH v2 3/4] btrfs-progs: Makefile: add extra objects definitions for separated binaries
2018-09-12 14:46 [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands Axel Burri
2018-09-12 14:46 ` [RFC PATCH v2 1/4] btrfs-progs: Makefile: create separated binaries for "btrfs" subcommands; add fscaps declarations Axel Burri
2018-09-12 14:46 ` [RFC PATCH v2 2/4] btrfs-progs: remove unneeded dependencies on separated build (-DBTRFS_SEPARATED_BUILD) Axel Burri
@ 2018-09-12 14:46 ` Axel Burri
2018-09-12 14:46 ` [RFC PATCH v2 4/4] btrfs-progs: build: add --enable-setcap-install, --enable-setuid-install, --enable-btrfs-separated Axel Burri
2018-09-19 22:02 ` [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands Axel Burri
4 siblings, 0 replies; 9+ messages in thread
From: Axel Burri @ 2018-09-12 14:46 UTC (permalink / raw)
To: linux-btrfs; +Cc: Axel Burri
Some separated binaries have references to specific command objects
($cmds_objects). Add these dependencies in the Makefile, and use them
in the linker target (as in target "btrfs-%:").
Fixes linkage errors for these subcommands. The "make separated"
target now builds without errors.
Signed-off-by: Axel Burri <axel@tty0.ch>
---
Makefile | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/Makefile b/Makefile
index 95db571b..362550c9 100644
--- a/Makefile
+++ b/Makefile
@@ -249,6 +249,15 @@ sc_cmds_all := $(sort $(foreach val,$(sc_map),$(firstword $(subst @, ,$(val)))))
sc_cmds := $(filter-out $(sc_exclude),$(sc_cmds_all))
sc_cmds_fscaps := $(sort $(subst @fscaps,,$(filter %@fscaps,$(subst :, ,$(sc_map)))))
+# Additional cmds_objects required for separated binaries
+btrfs_device_add_objects = mkfs/common.o
+btrfs_device_usage_objects = cmds-fi-usage.o
+btrfs_filesystem_show_objects = cmds-fi-usage.o
+btrfs_replace_start_objects = mkfs/common.o
+btrfs_rescue_super_recover_objects = super-recover.o
+btrfs_rescue_chunk_recover_objects = check/mode-lowmem.o check/mode-common.o check/main.o chunk-recover.o
+btrfs_restore_objects = $(LIBS_COMP)
+
# Using suffix allows strict distinction in targets below (btrfs-%.separated[.o])
progs_separated = $(addsuffix .separated,$(sc_cmds))
progs_separated_fscaps = $(addsuffix .separated,$(sc_cmds_fscaps))
@@ -504,6 +513,7 @@ btrfs-%.static: btrfs-%.static.o $(static_objects) $(patsubst %.o,%.static.o,$(s
btrfs-%.separated: btrfs-%.separated.o $(objects) $(cmds_objects) $(libs_static)
@echo " [LD] $@"
$(Q)$(CC) -o $@ $@.o $(objects) $(libs_static) \
+ $($(subst -,_,$(@:%.separated=%)-objects)) \
$(LDFLAGS) $(LIBS)
btrfs-%: btrfs-%.o $(objects) $(standalone_deps) $(libs_static)
--
2.16.4
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [RFC PATCH v2 4/4] btrfs-progs: build: add --enable-setcap-install, --enable-setuid-install, --enable-btrfs-separated
2018-09-12 14:46 [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands Axel Burri
` (2 preceding siblings ...)
2018-09-12 14:46 ` [RFC PATCH v2 3/4] btrfs-progs: Makefile: add extra objects definitions for separated binaries Axel Burri
@ 2018-09-12 14:46 ` Axel Burri
2018-09-19 22:02 ` [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands Axel Burri
4 siblings, 0 replies; 9+ messages in thread
From: Axel Burri @ 2018-09-12 14:46 UTC (permalink / raw)
To: linux-btrfs; +Cc: Axel Burri
Adds Makefile target "install-separated": install all
"btrfs-*.separated" binaries and rename to "btrfs-*". If configured
with --enable-setcap-install, also sets linux capabilities(7) using
setcap(8). If configured with "--enable-setuid-install", sets setuid
bit while installing.
Use --enable-btrfs-separated if you want to build (but not install)
all "btrfs-*.separated" binaries.
Signed-off-by: Axel Burri <axel@tty0.ch>
---
Makefile | 36 +++++++++++++++++++++++++++++++++++-
Makefile.inc.in | 6 ++++++
configure.ac | 40 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 81 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile
index 362550c9..e0edcb75 100644
--- a/Makefile
+++ b/Makefile
@@ -232,6 +232,25 @@ progs_install =
progs_build =
endif
+ifeq ($(BUILD_BTRFS_SEPARATED),1)
+# Note: intentionally not addded to progs_install:
+# use -enable-setcap-install, --enable-setuid-install instead.
+progs_build += $(progs_separated)
+endif
+
+INSTALL_SEPARATED_OPTIONS = -m755
+ifeq ($(ENABLE_INSTALL_SETCAP),1)
+INSTALL_SEPARATED_OPTIONS = -m710
+progs_install_separated += $(progs_separated_fscaps)
+endif
+ifeq ($(ENABLE_INSTALL_SETUID),1)
+INSTALL_SEPARATED_OPTIONS = -m4710
+progs_install_separated += $(progs_separated_fscaps)
+endif
+ifdef SETCAP_GROUP
+INSTALL_SEPARATED_OPTIONS += -g$(SETCAP_GROUP)
+endif
+
# Parse "int cmd_xxx_yyy(int argc, char **argv)" lines in cfiles, and
# create whitespace separated map of form: "btrfs-xxx-yyy@key:value".
sc_cfiles := $(wildcard cmds-*.c)
@@ -704,7 +723,7 @@ $(CLEANDIRS):
@echo "Cleaning $(patsubst clean-%,%,$@)"
$(Q)$(MAKE) $(MAKEOPTS) -C $(patsubst clean-%,%,$@) clean
-install: $(libs_build) $(progs_install) $(INSTALLDIRS)
+install: $(libs_build) $(progs_install) $(progs_install_separated) $(INSTALLDIRS)
ifeq ($(BUILD_PROGRAMS),1)
$(INSTALL) -m755 -d $(DESTDIR)$(bindir)
$(INSTALL) $(progs_install) $(DESTDIR)$(bindir)
@@ -726,6 +745,9 @@ endif
$(INSTALL) -m644 $(libbtrfs_headers) $(DESTDIR)$(incdir)/btrfs
$(INSTALL) -m644 libbtrfsutil/btrfsutil.h $(DESTDIR)$(incdir)
endif
+ifeq ($(BUILD_BTRFS_SEPARATED),1)
+ $(Q)$(MAKE) $(MAKEOPTS) install-separated
+endif
ifeq ($(PYTHON_BINDINGS),1)
install_python: libbtrfsutil_python
@@ -741,6 +763,18 @@ install-static: $(progs_static) $(INSTALLDIRS)
# btrfsck is a link to btrfs in the src tree, make it so for installed file as well
$(LN_S) -f btrfs.static $(DESTDIR)$(bindir)/btrfsck.static
+# install separated btrfs binaries, set linux capabilities(7) defined
+# in "@SEPARATED" lines using setcap(8), remove ".separated" postfix
+install-btrfs-%.separated: btrfs-%.separated
+ $(INSTALL) -m755 -d $(DESTDIR)$(bindir)
+ $(INSTALL) $(INSTALL_SEPARATED_OPTIONS) $< $(DESTDIR)$(bindir)
+ifeq ($(ENABLE_INSTALL_SETCAP),1)
+ $(SETCAP) $(call sc_get,$(<:%.separated=%),fscaps)+ep $(DESTDIR)$(bindir)/$<
+endif
+ $(MV) $(DESTDIR)$(bindir)/$< $(DESTDIR)$(bindir)/$(<:%.separated=%)
+
+install-separated: $(progs_install_separated) $(patsubst %,install-%,$(progs_install_separated))
+
$(INSTALLDIRS):
@echo "Making install in $(patsubst install-%,%,$@)"
$(Q)$(MAKE) $(MAKEOPTS) -C $(patsubst install-%,%,$@) install
diff --git a/Makefile.inc.in b/Makefile.inc.in
index a86c528e..93df2edf 100644
--- a/Makefile.inc.in
+++ b/Makefile.inc.in
@@ -10,6 +10,8 @@ AR = @AR@
RM = @RM@
RMDIR = @RMDIR@
INSTALL = @INSTALL@
+MV = @MV@
+SETCAP = @SETCAP@
DISABLE_DOCUMENTATION = @DISABLE_DOCUMENTATION@
DISABLE_BTRFSCONVERT = @DISABLE_BTRFSCONVERT@
BUILD_PROGRAMS = @BUILD_PROGRAMS@
@@ -22,6 +24,10 @@ PYTHON_BINDINGS = @PYTHON_BINDINGS@
PYTHON = @PYTHON@
PYTHON_CFLAGS = @PYTHON_CFLAGS@
+BUILD_BTRFS_SEPARATED = @BUILD_BTRFS_SEPARATED@
+ENABLE_INSTALL_SETCAP = @ENABLE_INSTALL_SETCAP@
+ENABLE_INSTALL_SETUID = @ENABLE_INSTALL_SETUID@
+
SUBST_CFLAGS = @CFLAGS@
SUBST_LDFLAGS = @LDFLAGS@
diff --git a/configure.ac b/configure.ac
index df02f206..981250bc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -39,6 +39,8 @@ AC_PROG_LN_S
AC_CHECK_TOOL([AR], [ar])
AC_PATH_PROG([RM], [rm], [rm])
AC_PATH_PROG([RMDIR], [rmdir], [rmdir])
+AC_PATH_PROG([MV], [mv], [mv])
+AC_PATH_PROG([SETCAP], [setcap], [setcap])
AC_CHECK_FUNCS([openat], [],
@@ -248,6 +250,40 @@ AS_IF([test "x$enable_python" = xyes], [PYTHON_BINDINGS=1], [PYTHON_BINDINGS=0])
AC_SUBST(PYTHON_BINDINGS)
AC_SUBST(PYTHON)
+# check whether to build/install separated btrfs binaries
+AC_ARG_ENABLE([setcap-install],
+ AS_HELP_STRING([--enable-setcap-install], [install separated binaries with capabilities]),
+ [], [enable_setcap_install=no]
+)
+AS_IF([test "x$enable_setcap_install" = xyes], [ENABLE_INSTALL_SETCAP=1], [ENABLE_INSTALL_SETCAP=0])
+AC_SUBST([ENABLE_INSTALL_SETCAP])
+AM_CONDITIONAL(SETCAP_INSTALL, test x$enable_setcap_install = xyes)
+
+AC_ARG_ENABLE([setuid-install],
+ AS_HELP_STRING([--enable-setuid-install], [install separated binaries as setuid]),
+ [], [enable_setuid_install=no]
+)
+AS_IF([test "x$enable_setuid_install" = xyes], [ENABLE_INSTALL_SETUID=1], [ENABLE_INSTALL_SETUID=0])
+AC_SUBST([ENABLE_INSTALL_SETUID])
+
+if test "x$enable_setcap_install" = "xyes"; then
+ enable_btrfs_separated=yes
+ if test "x$enable_setuid_install" = "xyes"; then
+ AC_MSG_RESULT(setcap and setuid both selected)
+ AC_MSG_ERROR(You must choose either setcap-install or setuid-install)
+ fi
+fi
+if test "x$enable_setuid_install" = "xyes"; then
+ enable_btrfs_separated=yes
+fi
+
+AC_ARG_ENABLE([btrfs-separated],
+ AS_HELP_STRING([--enable-btrfs-separated], [build separated binaries for btrfs subcommands]),
+ [], [enable_btrfs_separated=no]
+)
+AS_IF([test "x$enable_btrfs_separated" = xyes], [BUILD_BTRFS_SEPARATED=1], [BUILD_BTRFS_SEPARATED=0])
+AC_SUBST([BUILD_BTRFS_SEPARATED])
+
# udev v190 introduced the btrfs builtin and a udev rule to use it.
# Our udev rule gives us the friendly dm names but isn't required (or valid)
# on earlier releases.
@@ -309,5 +345,9 @@ AC_MSG_RESULT([
Python bindings: ${enable_python}
Python interpreter: ${PYTHON}
+ separated progs: ${enable_btrfs_separated}
+ Install separated progs with capabilities: ${enable_setcap_install}
+ Install separated progs suid: ${enable_setuid_install}
+
Type 'make' to compile.
])
--
2.16.4
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands
2018-09-12 14:46 [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands Axel Burri
` (3 preceding siblings ...)
2018-09-12 14:46 ` [RFC PATCH v2 4/4] btrfs-progs: build: add --enable-setcap-install, --enable-setuid-install, --enable-btrfs-separated Axel Burri
@ 2018-09-19 22:02 ` Axel Burri
2018-09-20 8:32 ` Duncan
4 siblings, 1 reply; 9+ messages in thread
From: Axel Burri @ 2018-09-19 22:02 UTC (permalink / raw)
To: linux-btrfs, Misono Tomohiro
In Reply to:
On 30/08/2018 04.38, Misono Tomohiro wrote:
>
> Hello,
>
> Not directly related this series and just FYI,
> I'm working to allow sub show/list to non-privileged user as long
> as he can access to the subvolume:
> https://www.spinics.net/lists/linux-btrfs/msg79285.html
>
> Hopefully this will be merged to master in near future
> (any comments from user/dev is welcome).
>
> Thanks,
> Misono
>
I found some time to play around with your patchset, it worked fine on
4.18.8-gentoo kernel.
As far as I can see, only "btrfs subvolume show" and "btrfs subvolume
list" makes sense for a regular user?
With the "cmds-separated-fscaps-v2" patchset [1], you can build
separated binaries as follows:
# make btrfs-subvolume-list.separated
# make btrfs-subvolume-show.separated
Now not everybody wants to install these with fscaps or setuid, but it
might also make sense to provide "/usr/bin/btrfs-subvolume-{show,list}",
as they now work for a regular user. Having both root/user binaries
concurrently is not an issue (e.g. in gentoo the full-featured btrfs
command is in "/sbin/").
Last time I checked, debian installs it to "/bin/btrfs", which from my
perspective seems to be the preferred location as soon as Misonos patch
is merged.
[1] https://github.com/digint/btrfs-progs/tree/cmds-separated-fscaps-v2
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands
2018-09-19 22:02 ` [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands Axel Burri
@ 2018-09-20 8:32 ` Duncan
2018-09-21 9:46 ` Axel Burri
0 siblings, 1 reply; 9+ messages in thread
From: Duncan @ 2018-09-20 8:32 UTC (permalink / raw)
To: linux-btrfs
Axel Burri posted on Thu, 20 Sep 2018 00:02:22 +0200 as excerpted:
> Now not everybody wants to install these with fscaps or setuid, but it
> might also make sense to provide "/usr/bin/btrfs-subvolume-{show,list}",
> as they now work for a regular user. Having both root/user binaries
> concurrently is not an issue (e.g. in gentoo the full-featured btrfs
> command is in "/sbin/").
That's going to be a problem for distros (or users like me with advanced
layouts, on gentoo too FWIW) that have the bin/sbin merge, where one is a
symlink to the other.
FWIW I have both the /usr merge (tho reversed for me, so /usr -> .
instead of having to have /bin and /sbin symlinks to /usr/bin) and the
bin/sbin merge, along with, since I'm on amd64-nomultilib, the lib/lib64
merge. So:
$$ dir -gGd /bin /sbin /usr /lib /lib64
drwxr-xr-x 1 35688 Sep 18 22:56 /bin
lrwxrwxrwx 1 5 Aug 7 00:29 /lib -> lib64
drwxr-xr-x 1 78560 Sep 18 22:56 /lib64
lrwxrwxrwx 1 3 Mar 11 2018 /sbin -> bin
lrwxrwxrwx 1 1 Mar 11 2018 /usr -> .
Of course that last one (/usr -> .) leads to /share and /include hanging
directly off of / as well, but it works.
But in that scheme /bin, /sbin, /usr/bin and /usr/sbin, are all the same
dir, so only one executable of a particularly name can exist therein.
--
Duncan - List replies preferred. No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master." Richard Stallman
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands
2018-09-20 8:32 ` Duncan
@ 2018-09-21 9:46 ` Axel Burri
2018-09-22 5:57 ` Duncan
0 siblings, 1 reply; 9+ messages in thread
From: Axel Burri @ 2018-09-21 9:46 UTC (permalink / raw)
To: Duncan, linux-btrfs, Misono Tomohiro
On 20/09/2018 10.32, Duncan wrote:
> Axel Burri posted on Thu, 20 Sep 2018 00:02:22 +0200 as excerpted:
>
>> Now not everybody wants to install these with fscaps or setuid, but it
>> might also make sense to provide "/usr/bin/btrfs-subvolume-{show,list}",
>> as they now work for a regular user. Having both root/user binaries
>> concurrently is not an issue (e.g. in gentoo the full-featured btrfs
>> command is in "/sbin/").
>
> That's going to be a problem for distros (or users like me with advanced
> layouts, on gentoo too FWIW) that have the bin/sbin merge, where one is a
> symlink to the other.
I think you got me wrong here: There will not be binaries with the same
filename. I totally agree that this would be a bad thing, no matter if
you have bin/sbin merged or not, you'll end up in either having a
collision or (even worse) rely on the order in $PATH.
With this "separated" patchset, you can install a binary
"btrfs-subvolume-show", which has the same functionality as "btrfs
subvolume show" (note the whitespace/dash), ending up with:
/sbin/btrfs
/usr/bin/btrfs-subvolume-show
/usr/bin/btrfs-subvolume-list
thus allowing a user to run "btrfs-subvolume-show" while "btrfs" is
still only visible for root. With /usr merge it would look like this:
/bin/btrfs
/bin/btrfs-subvolume-show
/bin/btrfs-subvolume-list
What I'm thinking of is a distro package which installs the separated
binaries, either with suid/fscaps (if the admin wants to provide their
users with non-restricted versions of specific commands), or without
special flags (if the admin wants to just provide the binaries that also
work for non-root user, enabled by Misono's patchset.
See my gentoo ebuild:
https://github.com/digint/gentoo/tree/btrfs-progs-separated/sys-fs/btrfs-progs-separated
>
> FWIW I have both the /usr merge (tho reversed for me, so /usr -> .
> instead of having to have /bin and /sbin symlinks to /usr/bin) and the
> bin/sbin merge, along with, since I'm on amd64-nomultilib, the lib/lib64
> merge. So:
>
> $$ dir -gGd /bin /sbin /usr /lib /lib64
> drwxr-xr-x 1 35688 Sep 18 22:56 /bin
> lrwxrwxrwx 1 5 Aug 7 00:29 /lib -> lib64
> drwxr-xr-x 1 78560 Sep 18 22:56 /lib64
> lrwxrwxrwx 1 3 Mar 11 2018 /sbin -> bin
> lrwxrwxrwx 1 1 Mar 11 2018 /usr -> .
>
>
> Of course that last one (/usr -> .) leads to /share and /include hanging
> directly off of / as well, but it works.
>
> But in that scheme /bin, /sbin, /usr/bin and /usr/sbin, are all the same
> dir, so only one executable of a particularly name can exist therein.
>
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [RFC PATCH v2 0/4] btrfs-progs: build distinct binaries for specific btrfs subcommands
2018-09-21 9:46 ` Axel Burri
@ 2018-09-22 5:57 ` Duncan
0 siblings, 0 replies; 9+ messages in thread
From: Duncan @ 2018-09-22 5:57 UTC (permalink / raw)
To: linux-btrfs
Axel Burri posted on Fri, 21 Sep 2018 11:46:37 +0200 as excerpted:
> I think you got me wrong here: There will not be binaries with the same
> filename. I totally agree that this would be a bad thing, no matter if
> you have bin/sbin merged or not, you'll end up in either having a
> collision or (even worse) rely on the order in $PATH.
>
> With this "separated" patchset, you can install a binary
> "btrfs-subvolume-show", which has the same functionality as "btrfs
> subvolume show" (note the whitespace/dash), ending up with:
>
> /sbin/btrfs
> /usr/bin/btrfs-subvolume-show
> /usr/bin/btrfs-subvolume-list
I did get you wrong (and had even understood the separately named
binaries from an earlier post, too, but forgot).
Thanks. =:^)
--
Duncan - List replies preferred. No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master." Richard Stallman
^ permalink raw reply [flat|nested] 9+ messages in thread