src/app/app.partcmd.pas

@@ -288,7 +288,9 @@ begin
     if bootrecord <> nil then begin
         if bootrecord^.boot_sector <> $AA55 then begin
             println('No valid mbr found, initialising disk...');
-            driver.storage.vol.mgr.init_disk(device);
+            if driver.storage.vol.mgr.init_disk(device) <> eNone then begin
+                println('Error: disk initialization failed.'); exit;
+            end;
         end;
         kfree(puint32(bootrecord));
     end;
@@ -335,7 +337,9 @@ begin
 
     driver.storage.vol.mbr.setup_partition(@part, lba, sectors);
     part.system_id := 0;
-    driver.storage.vol.mgr.add_partition(device, slot, part);
+    if driver.storage.vol.mgr.add_partition(device, slot, part) <> eNone then begin
+        println('Error: partition creation failed.'); exit;
+    end;
 
     print('Partition added in slot ');
     printint(slot);
@@ -407,7 +411,9 @@ begin
         exit;
     end;
 
-    driver.storage.vol.mgr.remove_partition(device, slot);
+    if driver.storage.vol.mgr.remove_partition(device, slot) <> eNone then begin
+        println('Error: partition removal failed.'); exit;
+    end;
 
     print('Partition slot ');
     printint(slot);
@@ -523,11 +529,14 @@ begin
         exit;
     end;
 
-    vol^.filesystem := fs;
-    fs^.createCallback(vol, vol^.sectorCount, vol^.sectorStart, nil);
-
-    { Re-probe filesystem so identify picks up the new signature }
-    driver.storage.fs.mgr.probe_volume(vol);
+    i := 0;
+    while i < driver.storage.vol.mgr.get_volume_count() do begin
+        if driver.storage.vol.mgr.get_volume(i) = vol then break;
+        Inc(i);
+    end;
+    if not driver.storage.vol.mgr.format_volume(device, i, fsName, nil) then begin
+        println('Error: format failed; the volume was not reported ready.'); exit;
+    end;
 
     print('Partition ');
     printint(slot);

src/arch/x86/system.pas

@@ -271,6 +271,7 @@ procedure fpc_shortstr_assign(len: longint; sstr, dstr: Pointer); compilerproc;
   any int64/uint64 arithmetic occurs (e.g. sint32 * uint32 promotion).
   Must live in the system unit so the compiler can resolve it. }
 function fpc_mul_int64(f1, f2: int64): int64; compilerproc;
+function fpc_mul_dword_to_qword(f1, f2: uint32): qword; compilerproc;
 function fpc_div_int64(d, n: int64): int64; compilerproc;
 function fpc_mod_int64(d, n: int64): int64; compilerproc;
 function fpc_mod_qword(d, n: qword): qword; compilerproc;
@@ -523,6 +524,18 @@ begin
     fpc_mul_int64 := res;
 end;
 
+function fpc_mul_dword_to_qword(f1, f2: uint32): qword; [public, alias: 'FPC_MUL_DWORD_TO_QWORD']; compilerproc;
+var res: qword;
+begin
+    asm
+        MOV EAX, f1
+        MUL f2
+        MOV DWORD [res], EAX
+        MOV DWORD [res+4], EDX
+    end;
+    fpc_mul_dword_to_qword := res;
+end;
+
 { ---------- 64-bit division / modulo ---------- }
 
 { Helper: unsigned 64÷64→64 using shift-subtract (binary long division).

src/driver/storage/driver.storage.types.pas

@@ -154,7 +154,8 @@ type
         sleVolumeInvalidated,
         sleVolumeRemoved,
         sleDeviceAdded,
-        sleDeviceRemoved
+        sleDeviceRemoved,
+        sleVolumeLabelChanged
     );
 
     TStorageLifecycleCallback = procedure(event : TStorageLifecycleEvent;
@@ -163,6 +164,8 @@ type
                                           error : TError;
                                           userdata : pointer);
 
+    TVolumeLabel = array[0..32] of char; { cached, NUL-terminated display name }
+
     TFSFormatParams = record
         Version     : uint16;
         Flags       : uint16;
@@ -186,13 +189,15 @@ type
     TIOCallback = procedure(error : TError; userdata : pointer);
 
     { Filesystem callback core.types }
-    PPCreateHook    = procedure(volume : PStorage_volume; start : uint32; size : uint32; config : PFSFormatParams);
+    PPCreateHook    = function(volume : PStorage_volume; sectors : uint32; start : uint32; config : PFSFormatParams) : TError;
     PPCreateAsyncHook = procedure(volume : PStorage_volume; start : uint32; size : uint32; config : PFSFormatParams; callback : TIOCallback; callbackData : pointer);
     PPDetectHook    = procedure(disk : PStorage_Device);
     PPCreateDirHook  = procedure(volume : PStorage_volume; directory : pchar; dirname : pchar; attributes : uint32; status : puint32);
     PPReadDirHook    = function(volume : PStorage_volume; directory : pchar; status : puint32) : PLinkedListBase;
     PPDeleteFileHook = procedure(volume : PStorage_Volume; filePath : pchar; status : puint32);
     PPDeleteDirHook  = procedure(volume : PStorage_Volume; path : pchar; status : puint32);
+    PPValidateLabelHook = function(text : pchar; var normalized : TVolumeLabel) : TError;
+    PPSetLabelHook = function(volume : PStorage_Volume; text : pchar) : TError;
     PPIdentifyHook   = function(volume : PStorage_Volume) : boolean;
     PPRenameFileHook = procedure(volume : PStorage_Volume; filePath : pchar; newName : pchar; status : puint32);
     { Offset-based read: reads byteCount bytes starting at byte offset into the file.
@@ -271,6 +276,8 @@ type
         maxSectorCount   : uint32;
         sectorSize       : uint32; //in bytes
         start            : uint32; //start of device in sectors
+        metadataBusy     : boolean; { volume/partition operation owns device }
+        mbrWriteBusy     : boolean; { serializes staged sector-zero writes }
         cachedMBR        : pointer;           { cached mbr data, nil if not yet read }
         isBootDevice     : boolean;           { true if this is the device GRUB booted from }
     end;
@@ -280,6 +287,7 @@ type
         sName              : pchar;
         system_id          : uint8;
         createCallback     : PPCreateHook;
+        validateFormat     : PPCreateHook; { pure preflight, before invalidation }
         detectCallback     : PPDetectHook;
         createDirCallback  : PPCreateDirHook;
         readDirCallback    : PPReadDirHook;
@@ -304,6 +312,8 @@ type
         openFileCallback        : PPOpenFileHook;
         closeFileCallback       : PPCloseFileHook;
         formatParamFlags        : uint32;
+        validateLabelCallback   : PPValidateLabelHook;
+        setLabelCallback        : PPSetLabelHook;
     end;
 
     { Generic storage volume }
@@ -317,6 +327,7 @@ type
         filesystem   : PFilesystem;
         isBootDrive  : boolean;
         lifecycleFlags : uint32;
+        labelText    : TVolumeLabel;
         fsPrivate    : pointer;      { FS-driver private data (e.g. PFATCache for FAT32) }
     end;
 

src/driver/storage/driver.storage.vfs.pas

@@ -134,6 +134,7 @@ procedure UnwatchDirectory(WatchID : uint32);
 { Volume invalidation — must be called before freeing a volume.
   Closes all open FDs referencing the volume across all processes,
   evicts directory cache entries, and removes VFS mount points. }
+function VolumeHasOpenHandles(vol : PStorage_Volume) : boolean;
 function InvalidateVolume(vol : PStorage_Volume) : boolean;
 
 { VFS Functions }
@@ -509,7 +510,7 @@ end;
 function GetObjectFromPath(path : pchar) : PVFSObject; forward;
 function GetObjectFromPathEx(path : pchar; var volRelPath : pchar) : PVFSObject; forward;
 
-function volumeHasAsyncHandles(vol : PStorage_Volume) : boolean;
+function volumeHasHandles(vol : PStorage_Volume; asyncOnly : boolean) : boolean;
 var
     pCount  : uint32;
     pi      : uint32;
@@ -517,7 +518,7 @@ var
     pCtx    : proc.types.PProcessContext;
     tbl     : PFDTable;
 begin
-    volumeHasAsyncHandles := false;
+    volumeHasHandles := false;
     if vol = nil then exit;
 
     pCount := proc.mgr.processCount();
@@ -530,14 +531,17 @@ begin
         if tbl = nil then continue;
         for fi := 0 to MAX_FDS - 1 do begin
             if tbl^.Entries[fi].InUse and (tbl^.Entries[fi].Volume = vol)
-               and (tbl^.Entries[fi].AsyncRefs > 0) then begin
-                volumeHasAsyncHandles := true;
+               and ((not asyncOnly) or (tbl^.Entries[fi].AsyncRefs > 0)) then begin
+                volumeHasHandles := true;
                 exit;
             end;
         end;
     end;
 end;
 
+function VolumeHasOpenHandles(vol : PStorage_Volume) : boolean;
+begin VolumeHasOpenHandles := volumeHasHandles(vol,false); end;
+
 function InvalidateVolume(vol : PStorage_Volume) : boolean;
 var
     pCount  : uint32;
@@ -554,7 +558,7 @@ begin
     debug.tracer.push_trace('driver.storage.vfs.InvalidateVolume.enter');
     InvalidateVolume := false;
     if vol = nil then exit;
-    if volumeHasAsyncHandles(vol) then begin
+    if volumeHasHandles(vol,true) then begin
         debug.tracer.push_trace('driver.storage.vfs.InvalidateVolume.busy');
         exit;
     end;
@@ -986,6 +990,7 @@ begin
     volumeGetDirectories := nil;
 
     if vol = nil then exit;
+    if (vol^.device = nil) or vol^.device^.metadataBusy or driver.storage.vol.mgr.volume_is_busy(vol) then exit;
     if vol^.filesystem = nil then exit;
     if vol^.filesystem^.readDirCallback = nil then exit;
 
@@ -1153,6 +1158,15 @@ begin
         exit;
     end;
 
+    mountObj := PVFSObject(core.ds.hashmap.get(ht, mountName));
+    if mountObj <> nil then begin
+        if (mountObj^.ObjectType = otDRIVE) and (mountObj^.Reference = void(volume)) then begin
+            mountVolume := pvRegistered;
+            driver.storage.vol.mgr.volume_set_mounted(volume, true);
+        end;
+        kfree(void(parentPath)); STRLL_Free(splitPath); exit;
+    end;
+
     { Create the mount object storing the volume pointer }
     mountObj := PVFSObject(kalloc(sizeof(TVFSObject)));
 
@@ -1219,6 +1233,12 @@ begin
     end;
 
     volOut^ := PStorage_Volume(Obj^.Reference);
+    if (volOut^ = nil) or (volOut^^.device = nil) then begin
+        if volRel <> nil then kfree(void(volRel)); exit;
+    end;
+    if volOut^^.device^.metadataBusy or driver.storage.vol.mgr.volume_is_busy(volOut^) then begin
+        if volRel <> nil then kfree(void(volRel)); volOut^ := nil; exit;
+    end;
 
     { volRel is the path within the volume, e.g. '/mydir/myfile.txt' }
     if (volRel = nil) or StringEquals(volRel, '/') then begin

src/driver/storage/fs/driver.storage.fs.iso9660.pas

@@ -392,6 +392,15 @@ end;
 
 { ==================== Filesystem callbacks ==================== }
 
+procedure cacheVolumeLabel(volume : PStorage_Volume; pvd : PPVD);
+var n, i : uint32;
+begin
+    memset(uint32(@volume^.labelText[0]),0,sizeof(volume^.labelText));
+    n := 32;
+    while (n > 0) and ((pvd^.volumeId[n-1] = ' ') or (pvd^.volumeId[n-1] = #0)) do Dec(n);
+    i := 0; while i < n do begin volume^.labelText[i] := pvd^.volumeId[i]; Inc(i); end;
+end;
+
 { Identify: check for 'CD001' at sector 16 }
 function identify_volume(volume : PStorage_Volume) : boolean;
 var
@@ -405,6 +414,7 @@ begin
     buf := readSectors(volume^.device, volume^.sectorStart + PVD_SECTOR, 1);
     if buf = nil then exit;
     identify_volume := isPVD(buf);
+    if identify_volume then cacheVolumeLabel(volume,PPVD(buf));
     kfree(buf);
 end;
 
@@ -437,6 +447,7 @@ begin
     volume^.filesystem  := @filesystem;
     volume^.isBootDrive := disk^.isBootDevice;
 
+    cacheVolumeLabel(volume,pvd);
     driver.storage.vol.mgr.register_volume(disk, volume);
 
     kfree(buf);

src/driver/storage/fs/fat32/driver.storage.fs.fat32.core.pas

@@ -94,10 +94,7 @@ end;
 
 function fatMaxClusterCount(bootRecord : PBootRecord) : uint32;
 begin
-    if (bootRecord = nil) or (bootRecord^.sectorSize = 0) then
-        fatMaxClusterCount := 0
-    else
-        fatMaxClusterCount := (bootRecord^.FATSize * bootRecord^.sectorSize) div 4;
+    fatMaxClusterCount := FAT32ClusterLimit(bootRecord);
 end;
 
 function fatClustersForBytes(byteCount : uint32; bytesPerCluster : uint32) : uint32;
@@ -391,7 +388,9 @@ begin
     sectorBuf := puint32(kalloc(bufSize));
     if sectorBuf = nil then exit;
     memset(uint32(sectorBuf), 0, bufSize);
-    driver.storage.mgr.storage_read(volume^.device, volume^.sectorStart, 1, sectorBuf);
+    if driver.storage.mgr.storage_read(volume^.device, volume^.sectorStart, 1, sectorBuf) <> eNone then begin
+        kfree(sectorBuf); exit;
+    end;
     bootRecord := PBootRecord(sectorBuf)^;
     kfree(sectorBuf);
     readBootRecordRaw := true;
@@ -699,9 +698,13 @@ begin
 
     { Keep runtime addressing compatible with the legacy formatter and metadata paths. }
     ctx^.Info.DataStart := volume^.sectorStart + ctx^.Info.BootRecord.rsvSectors +
-        ctx^.Info.BootRecord.FATSize;
+        uint32(ctx^.Info.BootRecord.numFats) * ctx^.Info.BootRecord.FATSize;
     ctx^.Info.BytesPerCluster := uint32(ctx^.Info.BootRecord.spc) * uint32(ctx^.Info.BootRecord.sectorSize);
     ctx^.Info.MaxCluster := fatMaxClusterCount(@ctx^.Info.BootRecord);
+    if (ctx^.Info.MaxCluster <= 2) or
+       (ctx^.Info.BootRecord.manySectors > volume^.sectorCount) then begin
+        fatCtxFree(ctx); exit;
+    end;
     ctx^.InfoValid := true;
 
     ctx^.Cache.Data := puint32(kalloc(FAT_CACHE_LINES * 512));
@@ -1135,6 +1138,7 @@ begin
         end;
         if dir^.fileName[0] = char($E5) then
             continue;
+        if (dir^.attributes and $08) <> 0 then continue; { volume labels and LFN entries are not files }
         if compareByteArray8(dir^.fileName, cleanName) and matchExtension(dir^.fileExtension, ext) then begin
             findEntryInSector := integer(idx);
             exit;
@@ -2048,7 +2052,7 @@ begin
                 end;
                 if dir^.fileName[0] = char($E5) then
                     continue;
-                if dir^.attributes = $0F then
+                if (dir^.attributes and $08) <> 0 then
                     continue;
                 if fatIsDotEntry(dir) then
                     continue;

src/driver/storage/fs/fat32/driver.storage.fs.fat32.pas

@@ -16,6 +16,7 @@ uses
     io.syslog,
     core.util,
     driver.storage.fs.fat32.vol,
+    driver.storage.fs.fat32.labels,
     driver.storage.fs.fat32.core,
     driver.storage.fs.fat32.transfer;
 
@@ -36,7 +37,8 @@ begin
     filesystem.readDirCallback := @FAT32ReadDirectory;
     filesystem.createDirCallback := @FAT32CreateDirectory;
     filesystem.createCallback := @create_volume;
-    filesystem.createAsyncCallback := @create_volume_async;
+    filesystem.validateFormat := @validate_format;
+    filesystem.createAsyncCallback := nil; { volume manager runs checked formatter in a worker }
     filesystem.detectCallback := @detect_volumes;
     filesystem.readOffsetCallback := @FAT32ReadFileAtOffset;
     filesystem.writeOffsetCallback := @FAT32WriteFileAtOffset;
@@ -51,7 +53,9 @@ begin
     filesystem.closeFileCallback := @FAT32CloseFile;
     filesystem.createDirAsyncCallback := nil;
     filesystem.readDirAsyncCallback := nil;
-    filesystem.formatParamFlags := FS_FORMAT_PARAM_CLUSTER_SIZE;
+    filesystem.formatParamFlags := FS_FORMAT_PARAM_CLUSTER_SIZE or FS_FORMAT_PARAM_LABEL;
+    filesystem.validateLabelCallback := @normalize_label;
+    filesystem.setLabelCallback := @write_label;
 
     FAT32VolInit(@filesystem);
     driver.storage.fs.mgr.register_filesystem(@filesystem);

src/driver/storage/fs/fat32/driver.storage.fs.fat32.types.pas

@@ -224,6 +224,28 @@ type
         WriteRefs         : array[0..FAT_OPEN_HANDLE_SLOTS - 1] of TFATWriteRef;
     end;
 
+{ Exclusive cluster bound, constrained by both data area and FAT capacity. }
+function FAT32ClusterLimit(br : PBootRecord) : uint32;
+
 implementation
 
+function FAT32ClusterLimit(br : PBootRecord) : uint32;
+var overhead, total, capacity, limit : uint64;
+begin
+    FAT32ClusterLimit := 0;
+    if br = nil then exit;
+    if (br^.sectorSize <> 512) or (br^.spc = 0) or (br^.spc > 128) or
+       ((br^.spc and (br^.spc - 1)) <> 0) or (br^.rsvSectors = 0) or
+       (br^.numFats = 0) or (br^.FATSize = 0) then exit;
+    total := br^.manySectors;
+    if total = 0 then total := br^.numSectors;
+    overhead := uint64(br^.rsvSectors) + uint64(br^.numFats) * br^.FATSize;
+    if overhead >= total then exit;
+    limit := (total - overhead) div br^.spc + 2;
+    capacity := uint64(br^.FATSize) * (br^.sectorSize div 4);
+    if (limit > capacity) or (limit > $0FFFFFF0) then exit;
+    FAT32ClusterLimit := uint32(limit);
+end;
+
+
 end.

src/driver/storage/vol/driver.storage.vol.mbr.pas

@@ -86,7 +86,7 @@ procedure set_bootable(partition_table : PPartition_table);
 begin
     push_trace('driver.storage.vol.mbr.set_bootable');
     //set the bootble bit in attributes
-    partition_table^.attributes := (partition_table^.attributes and $80);
+    partition_table^.attributes := (partition_table^.attributes or $80);
 end;
 
 { Check a partitions bootable bit }
@@ -105,7 +105,7 @@ begin
     partition_table^.LBA_start := address;
     partition_table^.sector_count := sectorSize;
     partition_table^.CHS_start := LBA_2_CHS(address);
-    partition_table^.CHS_start := LBA_2_CHS(address + sectorSize);  
+    partition_table^.CHS_end := LBA_2_CHS(address + sectorSize - 1);
     push_trace('driver.storage.vol.mbr.setup_partition.end');
 end;
 

src/test/test.pas

@@ -12,6 +12,7 @@ implementation
 
 uses
     core.strings,
+    app.diskutil,
     driver.bus.usb.types,
     driver.bus.usb.core,
     driver.bus.usb.uhci,
@@ -32,6 +33,7 @@ uses
     core.ds.prio,
     driver.storage.vfs,
     driver.storage.test,
+    driver.storage.metatest,
     core.enc.fnv1a,
     core.enc.djb2,
     core.ds.bloom,
@@ -46,6 +48,7 @@ procedure runAllTests();
 begin
     { Run unit tests }
     core.strings.UnitTest;
+    app.diskutil.UnitTest;
     driver.bus.usb.types.UnitTest;
     driver.bus.usb.core.UnitTest;
     driver.bus.usb.uhci.UnitTest;
@@ -66,6 +69,7 @@ begin
     core.ds.prio.UnitTest;
     driver.storage.vfs.UnitTest;
     driver.storage.test.UnitTest;
+    driver.storage.metatest.UnitTest;
     core.enc.fnv1a.UnitTest;
     core.enc.djb2.UnitTest;
     core.ds.bloom.UnitTest;