Use dmpart for partition tables instead of a private parser

CMakeLists.txt

@@ -79,7 +79,6 @@ set(DMOD_MAL_IMPLS         dmdrvi)
 dmod_add_library(${DMOD_MODULE_NAME} ${DMOD_MODULE_VERSION}
     # List of source files - can include C and C++ files
     src/dmdevfs.c
-    src/partitions.c
 )
 
 # Link to other DMOD modules (will be downloaded on build time)
@@ -92,6 +91,7 @@ dmod_link_modules(${DMOD_MODULE_NAME}
     dmini
     dmlist
     dmosi
+    dmpart
     libsystemd
 )
 

README.md

@@ -250,9 +250,14 @@ partition table and creates one node per partition next to it:
 
 | Table | Detected by | Numbers |
 |-------|-------------|---------|
-| MBR | `0x55AA` signature, valid status bytes, entries inside the medium; a FAT boot sector (superfloppy) is *not* taken for an MBR | primaries `1`-`4` by slot (empty slots leave gaps), logical partitions of an extended partition (`0x05`, `0x0F`, `0x85`) from `5` in chain order |
+| MBR | `0x55AA` signature, valid status bytes, entries inside the medium; a FAT or exFAT boot sector (superfloppy) is *not* taken for an MBR | primaries `1`-`4` by slot (empty slots leave gaps), logical partitions of an extended partition (`0x05`, `0x0F`, `0x85`) from `5` in chain order |
 | GPT | protective MBR (`0xEE`), then the `EFI PART` header at LBA 1 with valid header and entry array CRC32; if the primary header is damaged, the backup at the last LBA | entry index + 1 |
 
+The table is parsed by [dmpart](https://github.com/choco-technologies/dmblkid/tree/main/libs/dmpart)
+(released with dmblkid) - the same parser dmblkid uses, so a medium that
+gets partition nodes here is always reported by dmblkid as a partition
+table, never as a filesystem to mount whole.
+
 A medium without a valid table (blank, superfloppy, damaged GPT with both
 headers corrupted) gets no partition nodes - the whole-medium node is the
 only one, as before. Block sizes of 512 to 4096 bytes are supported.
@@ -581,8 +586,7 @@ dmdevfs/
 ├── include/
 │   └── dmdevfs.h            # Public header
 ├── src/
-│   ├── dmdevfs.c            # Main DMDEVFS implementation
-│   └── partitions.c/.h      # MBR/GPT partition table parser
+│   └── dmdevfs.c            # Main DMDEVFS implementation
 ├── services/
 │   └── dmdevmon/            # generic monitor service (rules + unit in configs/)
 ├── tests/

src/dmdevfs.c

@@ -17,7 +17,7 @@
 #include "dmdrvi.h"
 #include "dmosi.h"
 #include "libsystemd.h"
-#include "partitions.h"
+#include "dmpart.h"
 #include <errno.h>
 #include <string.h>
 
@@ -3125,7 +3125,7 @@ typedef struct
 } partition_scan_t;
 
 /**
- * @brief dmdevfs_part_read_t through the parent's driver
+ * @brief dmpart_read_t through the parent's driver
  */
 static int partition_read( void* ctx, uint64_t offset, void* buffer, size_t size )
 {
@@ -3164,7 +3164,7 @@ static driver_node_t* create_partition_node( const driver_node_t* parent, uint32
 }
 
 /**
- * @brief dmdevfs_part_found_t collecting partition nodes
+ * @brief dmpart_found_t collecting partition nodes
  */
 static bool on_partition_found( void* ctx, uint32_t number, uint64_t first_lba, uint64_t lba_count )
 {
@@ -3208,8 +3208,12 @@ static dmlist_context_t* find_partitions( driver_node_t* node )
         (found = dmlist_create()) != NULL)
     {
         partition_scan_t scan = { node, dmdrvi_read, handle, info.logical_block_size, found };
-        dmdevfs_partitions_scan(partition_read, &scan, info.logical_block_size, info.block_count,
-                                on_partition_found, &scan);
+        dmpart_medium_t medium = { partition_read, &scan, info.logical_block_size, info.block_count };
+        dmpart_info_t table;
+        if (dmpart_scan(&medium, on_partition_found, &scan, &table) == -ENOMEM)
+        {
+            DMOD_LOG_ERROR("Out of memory reading the partition table of %s\n", node->path);
+        }
     }
     dmdrvi_close(node->driver_context, handle);
     return found;