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fix write_fd_block

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ІО-23 Шмуляр Олег 2025-04-30 22:46:35 +03:00
parent ba8f8031f0
commit e39815a2e7
1 changed files with 24 additions and 63 deletions
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87
src/fs.c
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@ -855,6 +855,11 @@ static void read_fd_block(unsigned int fd, unsigned int block_index, unsigned ch
else
memset(buf, 0, FS_BLOCK_SIZE);
} else {
/*
* TODO: rewrite this potentially broken abomination normally
* it has not caused issues so far, but you can never be too sure
*/
int ext_no = (block_index - BLOCK_ADDRESSES_PER_INODE) / BLOCK_ADDRESSES_PER_INODE_EXTENSION;
int ext_offset = (block_index - BLOCK_ADDRESSES_PER_INODE) % BLOCK_ADDRESSES_PER_INODE_EXTENSION;
@ -928,17 +933,14 @@ static int write_fd_block(unsigned int fd, unsigned int block_index, unsigned ch
write_block(fs_file_descriptions[fd].inode, (void *) &f);
}
unsigned int target_extension_address;
unsigned int previous_extension_address = f.next_extension;
unsigned int i;
unsigned int next_ext = f.next_extension;
unsigned int curr_ext = 0;
struct fs_inode_extension ext;
// seek to target extension address
for (
target_extension_address = previous_extension_address, i = 0;
(i < ext_no);
i++
) {
if (!target_extension_address) {
for (unsigned int i = 0; i < ext_no + 1; i++) {
if (!next_ext) {
int new_block = find_free_block();
if (!new_block) {
pr_err("failed to write to fd=%d block=%d: can't allocate block for inode extension\n",
@ -947,76 +949,35 @@ static int write_fd_block(unsigned int fd, unsigned int block_index, unsigned ch
}
mark_used(new_block);
// updating previous inode extension
struct fs_inode_extension prev_ext;
read_block(previous_extension_address, (void *) &prev_ext); // read
prev_ext.next_extension = new_block; // modify
write_block(previous_extension_address, (void *) &prev_ext); // write
ext.next_extension = new_block;
write_block(curr_ext, (void *) &ext);
// writing new inode extension
struct fs_inode_extension ext;
memset(&ext, 0, sizeof(struct fs_inode_extension));
write_block(target_extension_address, (void *) &ext);
struct fs_inode_extension new_ext;
memset(&new_ext, 0, sizeof(struct fs_inode_extension));
write_block(new_block, (void *) &new_ext);
target_extension_address = new_block;
next_ext = new_block;
}
struct fs_inode_extension ext;
read_block(target_extension_address, (void *) &ext);
previous_extension_address = target_extension_address;
target_extension_address = ext.next_extension;
curr_ext = next_ext;
read_block(curr_ext, (void *) &ext);
next_ext = ext.next_extension;
}
if (!target_extension_address) {
int new_block = find_free_block();
if (!new_block) {
pr_err("failed to write to fd=%d block=%d: can't allocate block for inode extension\n",
fd, block_index);
return -1;
}
struct fs_inode_extension prev_ext;
read_block(previous_extension_address, (void *) &prev_ext); // read
prev_ext.next_extension = new_block; // modify
write_block(previous_extension_address, (void *) &prev_ext); // write
if (!ext.blocks[ext_offset]) {
int new_data_block = find_free_block();
if (!new_data_block) {
pr_err("failed to write to fd=%d block=%d: can't allocate block for data\n",
fd, block_index);
return -1;
}
mark_used(new_block);
mark_used(new_data_block);
// writing new inode extension
struct fs_inode_extension ext;
memset(&ext, 0, sizeof(struct fs_inode_extension));
ext.blocks[ext_offset] = new_data_block;
write_block(target_extension_address, (void *) &ext);
// writing new data block
write_block(new_data_block, (void *) buf);
} else {
struct fs_inode_extension ext;
read_block(target_extension_address, (void *) &ext);
if (!ext.blocks[ext_offset]) {
int new_data_block = find_free_block();
if (!new_data_block) {
pr_err("failed to write to fd=%d block=%d: can't allocate block for data\n",
fd, block_index);
return -1;
}
mark_used(new_data_block);
ext.blocks[ext_offset] = new_data_block;
write_block(target_extension_address, (void *) &ext);
}
write_block(ext.blocks[ext_offset], (void *) buf);
write_block(curr_ext, (void *) &ext);
}
write_block(ext.blocks[ext_offset], (void *) buf);
}
}