dissect: drop partition removal code

This reverts a major chunk of 75d7e04eb4

Now that the loopback device code already destroys the partitions we
don't have to do this here anymore.

I am sure the right place to delete the partitions is in the loopback
code, since we really only should do that for loopback devices, see
bug #24431, and not on "real" block devices.

I am also not convinced dropping partitions the dissection logic doesn't
care about is a good idea, after all. The dissection stuff should
probably not consider itself the "owner" of the block devices it
analyzes, but take a more passive role: figure out what is what, but not
modify it.

Fixes: #24431

src/core/namespace.c

@@ -2432,7 +2432,6 @@ int setup_namespace(
                         }
                 }
 
-                dissected_image_relinquish(dissected_image);
                 loop_device_relinquish(loop_device);
 
         } else if (root_directory) {

src/dissect/dissect.c

@@ -685,7 +685,6 @@ static int action_mount(DissectedImage *m, LoopDevice *d) {
                         return log_error_errno(r, "Failed to relinquish DM devices: %m");
         }
 
-        dissected_image_relinquish(m);
         loop_device_relinquish(d);
         return 0;
 }
@@ -738,7 +737,6 @@ static int action_copy(DissectedImage *m, LoopDevice *d) {
                         return log_error_errno(r, "Failed to relinquish DM devices: %m");
         }
 
-        dissected_image_relinquish(m);
         loop_device_relinquish(d);
 
         if (arg_action == ACTION_COPY_FROM) {

src/gpt-auto-generator/gpt-auto-generator.c

@@ -772,8 +772,6 @@ static int enumerate_partitions(dev_t devnum) {
                         r = k;
         }
 
-        dissected_image_relinquish(m);
-
         return r;
 }
 

src/shared/dissect-image.c

@@ -150,20 +150,9 @@ static void check_partition_flags(
 }
 #endif
 
-static void dissected_partition_done(int fd, DissectedPartition *p) {
-        assert(fd >= 0);
+static void dissected_partition_done(DissectedPartition *p) {
         assert(p);
 
-#if HAVE_BLKID
-        if (p->node && p->partno > 0 && !p->relinquished) {
-                int r;
-
-                r = block_device_remove_partition(fd, p->node, p->partno);
-                if (r < 0)
-                        log_debug_errno(r, "BLKPG_DEL_PARTITION failed, ignoring: %m");
-        }
-#endif
-
         free(p->fstype);
         free(p->node);
         free(p->label);
@@ -312,14 +301,9 @@ int dissect_image(
                 return -ENOMEM;
 
         *m = (DissectedImage) {
-                .fd = -1,
                 .has_init_system = -1,
         };
 
-        m->fd = fcntl(fd, F_DUPFD_CLOEXEC, 3);
-        if (m->fd < 0)
-                return -errno;
-
         r = sd_device_get_sysname(d, &sysname);
         if (r < 0)
                 return log_debug_errno(r, "Failed to get device sysname: %m");
@@ -775,14 +759,10 @@ int dissect_image(
                                          * scheme in OS images. */
 
                                         if (!PARTITION_DESIGNATOR_VERSIONED(designator) ||
-                                            strverscmp_improved(m->partitions[designator].label, label) >= 0) {
-                                                r = block_device_remove_partition(fd, node, nr);
-                                                if (r < 0)
-                                                        log_debug_errno(r, "BLKPG_DEL_PARTITION failed, ignoring: %m");
+                                            strverscmp_improved(m->partitions[designator].label, label) >= 0)
                                                 continue;
-                                        }
 
-                                        dissected_partition_done(fd, m->partitions + designator);
+                                        dissected_partition_done(m->partitions + designator);
                                 }
 
                                 if (fstype) {
@@ -852,12 +832,8 @@ int dissect_image(
                                 const char *sid, *options = NULL;
 
                                 /* First one wins */
-                                if (m->partitions[PARTITION_XBOOTLDR].found) {
-                                        r = block_device_remove_partition(fd, node, nr);
-                                        if (r < 0)
-                                                log_debug_errno(r, "BLKPG_DEL_PARTITION failed, ignoring: %m");
+                                if (m->partitions[PARTITION_XBOOTLDR].found)
                                         continue;
-                                }
 
                                 sid = blkid_partition_get_uuid(pp);
                                 if (sid)
@@ -1171,9 +1147,8 @@ DissectedImage* dissected_image_unref(DissectedImage *m) {
                 return NULL;
 
         for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++)
-                dissected_partition_done(m->fd, m->partitions + i);
+                dissected_partition_done(m->partitions + i);
 
-        safe_close(m->fd);
         free(m->image_name);
         free(m->hostname);
         strv_free(m->machine_info);
@@ -1183,16 +1158,6 @@ DissectedImage* dissected_image_unref(DissectedImage *m) {
         return mfree(m);
 }
 
-void dissected_image_relinquish(DissectedImage *m) {
-        assert(m);
-
-        /* Partitions are automatically removed when the underlying loop device is closed. We just need to
-         * make sure we don't try to remove the partitions early. */
-
-        for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++)
-                m->partitions[i].relinquished = true;
-}
-
 static int is_loop_device(const char *path) {
         char s[SYS_BLOCK_PATH_MAX("/../loop/")];
         struct stat st;
@@ -3046,7 +3011,6 @@ int mount_image_privately_interactively(
                         return log_error_errno(r, "Failed to relinquish DM devices: %m");
         }
 
-        dissected_image_relinquish(dissected_image);
         loop_device_relinquish(d);
 
         *ret_directory = TAKE_PTR(created_dir);
@@ -3209,7 +3173,6 @@ int verity_dissect_and_mount(
                         return log_debug_errno(r, "Failed to relinquish decrypted image: %m");
         }
 
-        dissected_image_relinquish(dissected_image);
         loop_device_relinquish(loop_device);
 
         return 0;

src/shared/dissect-image.h

@@ -31,7 +31,6 @@ struct DissectedPartition {
         char *mount_options;
         uint64_t size;
         uint64_t offset;
-        bool relinquished;
 };
 
 typedef enum PartitionDesignator {
@@ -204,8 +203,6 @@ typedef enum DissectImageFlags {
 } DissectImageFlags;
 
 struct DissectedImage {
-        int fd;                    /* Backing fd */
-
         bool encrypted:1;
         bool has_verity:1;         /* verity available in image, but not necessarily used */
         bool has_verity_sig:1;     /* pkcs#7 signature embedded in image */
@@ -261,7 +258,6 @@ int dissect_image_and_warn(int fd, const char *name, const VeritySettings *verit
 
 DissectedImage* dissected_image_unref(DissectedImage *m);
 DEFINE_TRIVIAL_CLEANUP_FUNC(DissectedImage*, dissected_image_unref);
-void dissected_image_relinquish(DissectedImage *m);
 
 int dissected_image_decrypt(DissectedImage *m, const char *passphrase, const VeritySettings *verity, DissectImageFlags flags, DecryptedImage **ret);
 int dissected_image_decrypt_interactively(DissectedImage *m, const char *passphrase, const VeritySettings *verity, DissectImageFlags flags, DecryptedImage **ret);

src/sysext/sysext.c

@@ -585,7 +585,6 @@ static int merge_subprocess(Hashmap *images, const char *workspace) {
                                         return log_error_errno(r, "Failed to relinquish DM devices: %m");
                         }
 
-                        dissected_image_relinquish(m);
                         loop_device_relinquish(d);
                         break;
                 }