From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 24 Nov 2021 17:31:51 +0000 (+0100)
Subject: homework: don't try to shift uidmap for already activated home areas
X-Git-Tag: v250-rc1~165^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6f2c813667018cc54f127a15a578a74071b0fa24;p=thirdparty%2Fsystemd.git

homework: don't try to shift uidmap for already activated home areas

When we want to operate on an already activated home area we so far
tried to reapply the uidmapping logic. We shouldn't do that, it's
already applied after all.

We only want to apply this for newly activated home areas. Hence check
for the right HomeSetupFlags flag for it HOME_SETUP_ALREADY_ACTIVATED.

The patch is actually in theory a two-liner. Except that so far we don#t
pass the HomeSetupFlags flags down all necessary functions where the
uidmap stuff will eventually run. Hence this larger than intended
commit.
---

diff --git a/src/home/homework-cifs.c b/src/home/homework-cifs.c
index b49b7b3dcdb..ed06d1f221d 100644
--- a/src/home/homework-cifs.c
+++ b/src/home/homework-cifs.c
@@ -145,6 +145,7 @@ int home_setup_cifs(
 
 int home_activate_cifs(
                 UserRecord *h,
+                HomeSetupFlags flags,
                 HomeSetup *setup,
                 PasswordCache *cache,
                 UserRecord **ret_home) {
@@ -165,7 +166,7 @@ int home_activate_cifs(
         if (r < 0)
                 return r;
 
-        r = home_refresh(h, setup, header_home, cache, NULL, &new_home);
+        r = home_refresh(h, flags, setup, header_home, cache, NULL, &new_home);
         if (r < 0)
                 return r;
 
diff --git a/src/home/homework-cifs.h b/src/home/homework-cifs.h
index dda1e0b876d..af8c466629a 100644
--- a/src/home/homework-cifs.h
+++ b/src/home/homework-cifs.h
@@ -6,6 +6,6 @@
 
 int home_setup_cifs(UserRecord *h, HomeSetupFlags flags, HomeSetup *setup);
 
-int home_activate_cifs(UserRecord *h, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_home);
+int home_activate_cifs(UserRecord *h, HomeSetupFlags flags, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_home);
 
 int home_create_cifs(UserRecord *h, HomeSetup *setup, UserRecord **ret_home);
diff --git a/src/home/homework-directory.c b/src/home/homework-directory.c
index af13fa026a9..c2b383b7cd5 100644
--- a/src/home/homework-directory.c
+++ b/src/home/homework-directory.c
@@ -58,6 +58,7 @@ int home_setup_directory(UserRecord *h, HomeSetup *setup) {
 
 int home_activate_directory(
                 UserRecord *h,
+                HomeSetupFlags flags,
                 HomeSetup *setup,
                 PasswordCache *cache,
                 UserRecord **ret_home) {
@@ -74,11 +75,11 @@ int home_activate_directory(
         assert_se(hdo = user_record_home_directory(h));
         hd = strdupa_safe(hdo);
 
-        r = home_setup(h, 0, setup, cache, &header_home);
+        r = home_setup(h, flags, setup, cache, &header_home);
         if (r < 0)
                 return r;
 
-        r = home_refresh(h, setup, header_home, cache, NULL, &new_home);
+        r = home_refresh(h, flags, setup, header_home, cache, NULL, &new_home);
         if (r < 0)
                 return r;
 
@@ -279,7 +280,7 @@ int home_resize_directory(
         if (r < 0)
                 return r;
 
-        r = home_maybe_shift_uid(h, setup);
+        r = home_maybe_shift_uid(h, flags, setup);
         if (r < 0)
                 return r;
 
diff --git a/src/home/homework-directory.h b/src/home/homework-directory.h
index ecbb2f143cb..fe03e5deb19 100644
--- a/src/home/homework-directory.h
+++ b/src/home/homework-directory.h
@@ -5,6 +5,6 @@
 #include "user-record.h"
 
 int home_setup_directory(UserRecord *h, HomeSetup *setup);
-int home_activate_directory(UserRecord *h, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_home);
+int home_activate_directory(UserRecord *h, HomeSetupFlags flags, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_home);
 int home_create_directory_or_subvolume(UserRecord *h, HomeSetup *setup, UserRecord **ret_home);
 int home_resize_directory(UserRecord *h, HomeSetupFlags flags, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_home);
diff --git a/src/home/homework-luks.c b/src/home/homework-luks.c
index 529796ad9c7..2e1c4c61701 100644
--- a/src/home/homework-luks.c
+++ b/src/home/homework-luks.c
@@ -1511,6 +1511,7 @@ static int home_auto_grow_luks(
 
 int home_activate_luks(
                 UserRecord *h,
+                HomeSetupFlags flags,
                 HomeSetup *setup,
                 PasswordCache *cache,
                 UserRecord **ret_home) {
@@ -1563,6 +1564,7 @@ int home_activate_luks(
 
         r = home_refresh(
                         h,
+                        flags,
                         setup,
                         luks_home_record,
                         cache,
diff --git a/src/home/homework-luks.h b/src/home/homework-luks.h
index f0f29b78f7d..0218de8ccdb 100644
--- a/src/home/homework-luks.h
+++ b/src/home/homework-luks.h
@@ -7,7 +7,7 @@
 
 int home_setup_luks(UserRecord *h, HomeSetupFlags flags, const char *force_image_path, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_luks_home);
 
-int home_activate_luks(UserRecord *h, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_home);
+int home_activate_luks(UserRecord *h, HomeSetupFlags flags, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_home);
 int home_deactivate_luks(UserRecord *h, HomeSetup *setup);
 int home_trim_luks(UserRecord *h, HomeSetup *setup);
 
diff --git a/src/home/homework.c b/src/home/homework.c
index ac52a011eda..864171faedc 100644
--- a/src/home/homework.c
+++ b/src/home/homework.c
@@ -788,6 +788,7 @@ static int chown_recursive_directory(int root_fd, uid_t uid) {
 
 int home_maybe_shift_uid(
                 UserRecord *h,
+                HomeSetupFlags flags,
                 HomeSetup *setup) {
 
         _cleanup_close_ int mount_fd = -1;
@@ -797,6 +798,10 @@ int home_maybe_shift_uid(
         assert(setup);
         assert(setup->root_fd >= 0);
 
+        /* If the home dir is already activated, then the UID shift is already applied. */
+        if (FLAGS_SET(flags, HOME_SETUP_ALREADY_ACTIVATED))
+                return 0;
+
         if (fstat(setup->root_fd, &st) < 0)
                 return log_error_errno(errno, "Failed to stat() home directory: %m");
 
@@ -820,6 +825,7 @@ int home_maybe_shift_uid(
 
 int home_refresh(
                 UserRecord *h,
+                HomeSetupFlags flags,
                 HomeSetup *setup,
                 UserRecord *header_home,
                 PasswordCache *cache,
@@ -840,7 +846,7 @@ int home_refresh(
         if (r < 0)
                 return r;
 
-        r = home_maybe_shift_uid(h, setup);
+        r = home_maybe_shift_uid(h, flags, setup);
         if (r < 0)
                 return r;
 
@@ -868,6 +874,7 @@ static int home_activate(UserRecord *h, UserRecord **ret_home) {
         _cleanup_(home_setup_done) HomeSetup setup = HOME_SETUP_INIT;
         _cleanup_(user_record_unrefp) UserRecord *new_home = NULL;
         _cleanup_(password_cache_free) PasswordCache cache = {};
+        HomeSetupFlags flags = 0;
         int r;
 
         assert(h);
@@ -898,7 +905,7 @@ static int home_activate(UserRecord *h, UserRecord **ret_home) {
         switch (user_record_storage(h)) {
 
         case USER_LUKS:
-                r = home_activate_luks(h, &setup, &cache, &new_home);
+                r = home_activate_luks(h, flags, &setup, &cache, &new_home);
                 if (r < 0)
                         return r;
 
@@ -907,14 +914,14 @@ static int home_activate(UserRecord *h, UserRecord **ret_home) {
         case USER_SUBVOLUME:
         case USER_DIRECTORY:
         case USER_FSCRYPT:
-                r = home_activate_directory(h, &setup, &cache, &new_home);
+                r = home_activate_directory(h, flags, &setup, &cache, &new_home);
                 if (r < 0)
                         return r;
 
                 break;
 
         case USER_CIFS:
-                r = home_activate_cifs(h, &setup, &cache, &new_home);
+                r = home_activate_cifs(h, flags, &setup, &cache, &new_home);
                 if (r < 0)
                         return r;
 
diff --git a/src/home/homework.h b/src/home/homework.h
index 750ad331c8e..882a3f500b3 100644
--- a/src/home/homework.h
+++ b/src/home/homework.h
@@ -80,9 +80,9 @@ int keyring_unlink(key_serial_t k);
 
 int home_setup(UserRecord *h, HomeSetupFlags flags, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_header_home);
 
-int home_refresh(UserRecord *h, HomeSetup *setup, UserRecord *header_home, PasswordCache *cache, struct statfs *ret_statfs, UserRecord **ret_new_home);
+int home_refresh(UserRecord *h, HomeSetupFlags flags, HomeSetup *setup, UserRecord *header_home, PasswordCache *cache, struct statfs *ret_statfs, UserRecord **ret_new_home);
 
-int home_maybe_shift_uid(UserRecord *h, HomeSetup *setup);
+int home_maybe_shift_uid(UserRecord *h, HomeSetupFlags flags, HomeSetup *setup);
 int home_populate(UserRecord *h, int dir_fd);
 
 int home_load_embedded_identity(UserRecord *h, int root_fd, UserRecord *header_home, UserReconcileMode mode, PasswordCache *cache, UserRecord **ret_embedded_home, UserRecord **ret_new_home);