feat: add 'allocated' flag to inode data block

Author: AdamStepan

src/inode.c

@@ -56,15 +56,20 @@ ex_status ex_inode_allocate_blocks(struct ex_inode *inode) {
 
     for (size_t i = 0; i < EX_DIRECT_BLOCKS; i++) {
 
-        inode->blocks[i] = ex_super_allocate_block();
+        size_t address = ex_super_allocate_block();
 
         // we are unable to allocate next block, we should deallocate all
         // already allocated blocks
-        if (inode->blocks[i] == EX_BLOCK_INVALID_ADDRESS) {
+        if (address == EX_BLOCK_INVALID_ADDRESS) {
             warning("failing to allocate nth (%lu) block", i);
             ex_inode_deallocate_blocks(inode);
             return INODE_BLOCK_ALLOCATION_FAILED;
         }
+
+        struct ex_data_block *block = &inode->blocks[i];
+
+        block->address = address;
+        block->allocated = 1;
     }
 
     return OK;
@@ -74,11 +79,11 @@ void ex_inode_deallocate_blocks(struct ex_inode *inode) {
 
     for (size_t i = 0; i < EX_DIRECT_BLOCKS; i++) {
 
-        if (inode->blocks[i] == EX_BLOCK_INVALID_ADDRESS) {
+        if (inode->blocks[i].address == EX_BLOCK_INVALID_ADDRESS) {
             break;
         }
 
-        ex_super_deallocate_block(inode->blocks[i]);
+        ex_super_deallocate_block(inode->blocks[i].address);
     }
 
     ex_super_deallocate_inode_block(inode->number);
@@ -564,7 +569,12 @@ ssize_t ex_inode_write(struct ex_inode *ino, size_t off, const char *data,
         ino->size += (off + amount) - ino->size;
     }
 
-    block_address addr = ino->blocks[start_block_idx];
+    block_address addr = ino->blocks[start_block_idx].address;
+    char allocated = ino->blocks[start_block_idx].allocated;
+
+    if (!allocated) {
+        // XXX: do allocation
+    }
 
     ex_device_write(ino->address, (void *)ino, sizeof(struct ex_inode));
     ex_device_write(addr + start_block_off, data, amount);
@@ -582,9 +592,9 @@ ssize_t ex_inode_read(struct ex_inode *ino, size_t off, char *buffer,
         return 0;
     }
 
-    size_t offset = ino->blocks[start_block_idx] + start_block_off;
+    size_t offset = ino->blocks[start_block_idx].address + start_block_off;
     ssize_t readed = 0;
-
+    // XXX: check if block is allocated
     // XXX: ignore status for now
     (void)ex_device_read_to_buffer(&readed, buffer, offset, amount);
 
@@ -650,7 +660,7 @@ struct ex_inode_block ex_inode_block_iterate(struct ex_inode *inode,
         goto done;
     }
 
-    block.address = inode->blocks[it->block_number];
+    block.address = inode->blocks[it->block_number].address;
     block.data = it->buffer;
 
     // XXX: add buffer into ex_block_iterator and use ex_device_read_to_buffer
@@ -713,3 +723,4 @@ int ex_inode_has_perm(struct ex_inode *ino, ex_permission perm, gid_t gid, uid_t
 
     return 0;
 }
+

src/inode.h

@@ -13,12 +13,18 @@
 #include <time.h>
 #include <unistd.h>
 
-#define EX_DIRECT_BLOCKS 256
+#define EX_DIRECT_BLOCKS 64
+#define EX_INDIRECT_BLOCKS 8
 
 extern const uint16_t EX_INODE_MAGIC1;
 extern const uint8_t EX_DIR_MAGIC1;
 extern const uint8_t EX_ENTRY_MAGIC1;
 
+struct ex_data_block {
+    uint64_t address: 63;
+    uint64_t allocated: 1;
+};
+
 struct ex_inode {
     // number of inode, it corresponds with allocated block number
     // e.g. number==0 means that inode has allocated first inode
@@ -50,7 +56,7 @@ struct ex_inode {
 
     // if an inode is file content is saved here directly in these blocks
     // if an inode is directory ex_dir_entries are saved in these blocks
-    block_address blocks[EX_DIRECT_BLOCKS];
+    struct ex_data_block blocks[EX_DIRECT_BLOCKS + EX_INDIRECT_BLOCKS];
 };
 
 struct ex_dir_entry {

src/super.h

@@ -23,6 +23,7 @@
 typedef size_t inode_address;
 typedef size_t block_address;
 
+// XXX: rename this, it's used only by block iterator
 struct ex_inode_block {
     // position in super block inodes block bitmap
     size_t id;