feat: add sfsMount and sfsUnmount to sfs

src/sfs.c

@@ -954,3 +954,155 @@ bool sfsFormat(void)
     memset(inodeBitmap, 0, (uint64)nsb.inodeBitmapBlocks * sfsBlockSize);
     memset(blockBitmap, 0, (uint64)nsb.blockBitmapBlocks * sfsBlockSize);
 
+    sb = nsb;
+    isMounted = true;
+
+    uint8 zeroBlk[sfsBlockSize];
+    memset(zeroBlk, 0, sizeof(zeroBlk));
+    for (uint32 i = 0; i < sb.inodeTableBlocks; i++)
+        blockWrite(sb.inodeTableStart + i, zeroBlk);
+
+    bitSet(inodeBitmap, 0);
+    bitSet(inodeBitmap, sfsRootInode);
+
+    SfsInode rootInode;
+    memset(&rootInode, 0, sizeof(rootInode));
+    rootInode.type = sfsTypeDir;
+    rootInode.linkCount = 1;
+    rootInode.mtime = rootInode.ctime = (uint32)rtcNow();
+    rootInode.mode = fsModeDefaultDir;
+    rootInode.uid = currentThreadUid();
+    rootInode.gid = currentThreadGid();
+    writeInodeRaw(sfsRootInode, &rootInode);
+
+    flushInodeBitmap();
+    flushBlockBitmap();
+    flushSuperblock();
+    return true;
+}
+
+bool sfsMount(void)
+{
+    if (!ataPresent())
+        return false;
+
+    uint8 buf[sfsBlockSize];
+    if (!ataReadSectors(sfsBaseLba, 1, buf))
+        return false;
+
+    SfsSuperblock onDisk;
+    memcpy(&onDisk, buf, sizeof(onDisk));
+    if (onDisk.magic != sfsMagic)
+        return sfsFormat();
+
+    sb = onDisk;
+
+    if (inodeBitmap) {
+        kfree(inodeBitmap);
+        inodeBitmap = nullptr;
+    }
+    if (blockBitmap) {
+        kfree(blockBitmap);
+        blockBitmap = nullptr;
+    }
+
+    inodeBitmap = (uint8*)kmalloc((uint64)sb.inodeBitmapBlocks * sfsBlockSize);
+    blockBitmap = (uint8*)kmalloc((uint64)sb.blockBitmapBlocks * sfsBlockSize);
+    if (!inodeBitmap || !blockBitmap)
+        return false;
+
+    for (uint32 i = 0; i < sb.inodeBitmapBlocks; i++)
+        if (!blockRead(sb.inodeBitmapStart + i, inodeBitmap + (uint64)i * sfsBlockSize))
+            return false;
+    for (uint32 i = 0; i < sb.blockBitmapBlocks; i++)
+        if (!blockRead(sb.blockBitmapStart + i, blockBitmap + (uint64)i * sfsBlockSize))
+            return false;
+
+    isMounted = true;
+    return true;
+}
+
+void sfsUnmount(void)
+{
+    if (!isMounted)
+        return;
+    flushInodeBitmap();
+    flushBlockBitmap();
+    flushSuperblock();
+    if (inodeBitmap) {
+        kfree(inodeBitmap);
+        inodeBitmap = nullptr;
+    }
+    if (blockBitmap) {
+        kfree(blockBitmap);
+        blockBitmap = nullptr;
+    }
+    isMounted = false;
+}
+
+bool sfsMounted(void)
+{
+    return isMounted;
+}
+
+uint64 sfsCapacityBytes(void)
+{
+    if (!isMounted)
+        return 0;
+    return (uint64)(sb.totalBlocks - sb.dataStart) * sfsBlockSize;
+}
+
+uint64 sfsFreeDataBlocks(void)
+{
+    if (!isMounted)
+        return 0;
+    uint32 dataBlockCount = sb.totalBlocks - sb.dataStart;
+    uint64 free = 0;
+    for (uint32 i = 0; i < dataBlockCount; i++)
+        if (!bitTest(blockBitmap, i))
+            free++;
+    return free;
+}
+
+int32 sfsLookup(const char* path)
+{
+    return lookupFrom(path, true, 0);
+}
+
+int32 sfsLookupNoFollow(const char* path)
+{
+    return lookupFrom(path, false, 0);
+}
+
+int32 sfsCreateFile(const char* path)
+{
+    return createNode(path, sfsTypeFile);
+}
+
+int32 sfsCreateDir(const char* path)
+{
+    return createNode(path, sfsTypeDir);
+}
+
+int32 sfsCreateFifo(const char* path)
+{
+    return createNode(path, sfsTypeFifo);
+}
+
+uint64 sfsGeneration(void)
+{
+    return formatGeneration;
+}
+
+int32 sfsCreateSymlink(const char* path, const char* target)
+{
+    if (!isMounted || !target)
+        return -1;
+    uint64 targetLen = strlen(target);
+    if (targetLen == 0 || targetLen > sfsSymlinkTargetMax)
+        return -1;
+
+    int32 newInode = createNode(path, sfsTypeSymlink);
+    if (newInode < 0)
+        return -1;
+