| 45,14 → 45,104 |
|---|
| #include <libadt/list.h> |
| #include "vfs.h" |
| |
| #define min(a, b) ((a) < (b) ? (a) : (b)) |
| |
| atomic_t plb_futex = FUTEX_INITIALIZER; |
| link_t plb_head; |
| link_t plb_head; /**< PLB entry ring buffer. */ |
| uint8_t *plb = NULL; |
| |
| void vfs_lookup(ipc_callid_t rid, ipc_call_t *request) |
| int vfs_lookup_internal(char *path, size_t len, vfs_node_t *result) |
| { |
| if (!len) |
| return EINVAL; |
| |
| if (!rootfs) |
| ipc_answer_fast(rid, ENOENT, 0, 0); |
| return ENOENT; |
| |
| futex_down(&plb_futex); |
| |
| plb_entry_t entry; |
| link_initialize(&entry.plb_link); |
| entry.len = len; |
| |
| off_t first; /* the first free index */ |
| off_t last; /* the last free index */ |
| |
| if (list_empty(&plb_head)) { |
| first = 0; |
| last = PLB_SIZE - 1; |
| } else { |
| plb_entry_t *oldest = list_get_instance(plb_head.next, |
| plb_entry_t, plb_link); |
| plb_entry_t *newest = list_get_instance(plb_head.prev, |
| plb_entry_t, plb_link); |
| |
| first = (newest->index + newest->len) % PLB_SIZE; |
| last = (oldest->index - 1) % PLB_SIZE; |
| } |
| |
| if (first <= last) { |
| if ((last - first) + 1 < len) { |
| /* |
| * The buffer cannot absorb the path. |
| */ |
| futex_up(&plb_futex); |
| return ELIMIT; |
| } |
| } else { |
| if (PLB_SIZE - ((first - last) + 1) < len) { |
| /* |
| * The buffer cannot absorb the path. |
| */ |
| futex_up(&plb_futex); |
| return ELIMIT; |
| } |
| } |
| |
| /* |
| * We know the first free index in PLB and we also know that there is |
| * enough space in the buffer to hold our path. |
| */ |
| |
| entry.index = first; |
| entry.len = len; |
| |
| /* |
| * Claim PLB space by inserting the entry into the PLB entry ring |
| * buffer. |
| */ |
| list_append(&entry.plb_link, &plb_head); |
| |
| futex_up(&plb_futex); |
| |
| /* |
| * Copy the path into PLB. |
| */ |
| size_t cnt1 = min(len, (PLB_SIZE - first) + 1); |
| size_t cnt2 = len - cnt1; |
| |
| memcpy(&plb[first], path, cnt1); |
| memcpy(plb, &path[cnt1], cnt2); |
| |
| ipc_call_t answer; |
| int phone = 0; /* TODO */ |
| aid_t req = async_send_2(phone, VFS_LOOKUP, (ipcarg_t) first, |
| (ipcarg_t) last, &answer); |
| |
| ipcarg_t rc; |
| async_wait_for(req, &rc); |
| |
| futex_down(&plb_futex); |
| list_remove(&entry.plb_link); |
| futex_up(&plb_futex); |
| |
| if (rc == EOK) { |
| result->fs_handle = (int) IPC_GET_ARG1(answer); |
| result->dev_handle = (int) IPC_GET_ARG2(answer); |
| result->index = (int) IPC_GET_ARG3(answer); |
| } |
| |
| return rc; |
| } |
| |
| /** |