void invalidate_buffer(struct bufpool *pool, vfs_blkno_t blkno)
{
struct buf *buf;
// If buffer is not in cache we are finished
buf = lookup_buffer(pool, blkno);
if (!buf) return;
// Mark buffer as invalid and release it
mark_buffer_invalid(buf);
release_buffer(pool, buf);
}
int delete_dir_entry(struct inode *dir, char *name, int len)
{
unsigned int block;
vfs_blkno_t blk;
vfs_blkno_t lastblk;
struct buf *buf;
char *p;
struct dentry *de;
struct dentry *prevde;
struct dentry *nextde;
if (len <= 0 || len >= MAXPATH) return -1;
if (!VFS_S_ISDIR(dir->desc->mode)) return -1;
for (block = 0; block < dir->desc->blocks; block++)
{
blk = get_inode_block(dir, block);
buf = get_buffer(dir->fs->cache, blk);
if (!buf) return -1;
p = buf->data;
prevde = NULL;
while (p < buf->data + dir->fs->blocksize)
{
de = (struct dentry *) p;
if (fnmatch(name, len, de->name, de->namelen))
{
if (prevde)
{
// Merge entry with previous entry
prevde->reclen += de->reclen;
memset(de, 0, sizeof(struct dentry) + NAME_ALIGN_LEN(de->namelen));
mark_buffer_updated(buf);
}
else if (de->reclen == dir->fs->blocksize)
{
// Block is empty, swap this block with last block and truncate
if (block != dir->desc->blocks - 1)
{
lastblk = get_inode_block(dir, dir->desc->blocks - 1);
set_inode_block(dir, block, lastblk);
set_inode_block(dir, dir->desc->blocks - 1, buf->blkno);
}
truncate_inode(dir, dir->desc->blocks - 1);
dir->desc->size -= dir->fs->blocksize;
mark_buffer_invalid(buf);
}
else
{
// Merge with next entry
nextde = (struct dentry *) (p + de->reclen);
de->ino = nextde->ino;
de->reclen += nextde->reclen;
de->namelen = nextde->namelen;
memcpy(de->name, nextde->name, nextde->namelen); // TODO: should be memmove?
mark_buffer_updated(buf);
}
release_buffer(dir->fs->cache, buf);
dir->desc->mtime = time(NULL);
mark_inode_dirty(dir);
return 0;
}
prevde = de;
p += de->reclen;
}
release_buffer(dir->fs->cache, buf);
}
return -1;
}
