70 lines
1.5 KiB
C
70 lines
1.5 KiB
C
#include <kernel/fs/gladfs.h>
|
|
#include <kernel/util/atomic.h>
|
|
#include <lib/string.h>
|
|
|
|
// Internal helper
|
|
extern struct gladfs_fragment_data_s **gladfs_file_pos(off_t *offset, struct gladfs_inode_s *inode, off_t pos);
|
|
|
|
/* gladfs_read() - GladFS inode read primitive (sync) */
|
|
ssize_t gladfs_read(void *inode, void *buf, size_t count, off_t pos)
|
|
{
|
|
struct gladfs_fragment_data_s **fragdata;
|
|
uint8_t get_next_block;
|
|
size_t current_size;
|
|
size_t write_size;
|
|
off_t offset;
|
|
|
|
// Start atomic operations
|
|
atomic_start();
|
|
|
|
// Get appropriate data fragment
|
|
fragdata = gladfs_file_pos(&offset, inode, pos);
|
|
if (fragdata == NULL || *fragdata == NULL)
|
|
{
|
|
atomic_stop();
|
|
return (-1);
|
|
}
|
|
|
|
// Walk into fragemented data
|
|
current_size = 0;
|
|
count = count - offset;
|
|
while (current_size < count)
|
|
{
|
|
// Generate writable zone
|
|
if ((*fragdata)->data_size - offset >= count - current_size)
|
|
{
|
|
write_size = count - current_size;
|
|
get_next_block = 0;
|
|
} else {
|
|
write_size = (*fragdata)->data_size - offset;
|
|
get_next_block = 1;
|
|
}
|
|
|
|
// Write data.
|
|
memcpy(
|
|
(void *)((uint32_t)buf + current_size),
|
|
(void *)((uint32_t)(&(*fragdata)->data_entry) + offset),
|
|
write_size
|
|
);
|
|
|
|
// Update current size and wipe offset
|
|
current_size = current_size + write_size;
|
|
offset = 0;
|
|
|
|
// Get next block if needed
|
|
if (get_next_block == 1)
|
|
{
|
|
// Get next block
|
|
fragdata = (void *)&(*fragdata)->next;
|
|
if (*fragdata == NULL)
|
|
break;
|
|
}
|
|
}
|
|
|
|
// End atomic operations
|
|
atomic_stop();
|
|
|
|
// Return read bytes
|
|
return (current_size);
|
|
}
|