2 * (C) 2001 Clemson University and The University of Chicago
4 * See COPYING in top-level directory.
7 #include "orangefs-kernel.h"
8 #include "orangefs-bufmap.h"
10 DECLARE_WAIT_QUEUE_HEAD(orangefs_bufmap_init_waitq);
12 /* used to describe mapped buffers */
13 struct orangefs_bufmap_desc {
14 void *uaddr; /* user space address pointer */
15 struct page **page_array; /* array of mapped pages */
16 int array_count; /* size of above arrays */
17 struct list_head list_link;
20 static struct orangefs_bufmap {
29 struct page **page_array;
30 struct orangefs_bufmap_desc *desc_array;
32 /* array to track usage of buffer descriptors */
33 int *buffer_index_array;
34 spinlock_t buffer_index_lock;
36 /* array to track usage of buffer descriptors for readdir */
37 int readdir_index_array[ORANGEFS_READDIR_DEFAULT_DESC_COUNT];
38 spinlock_t readdir_index_lock;
41 static DEFINE_SPINLOCK(orangefs_bufmap_lock);
44 orangefs_bufmap_unmap(struct orangefs_bufmap *bufmap)
48 for (i = 0; i < bufmap->page_count; i++)
49 page_cache_release(bufmap->page_array[i]);
53 orangefs_bufmap_free(struct orangefs_bufmap *bufmap)
55 kfree(bufmap->page_array);
56 kfree(bufmap->desc_array);
57 kfree(bufmap->buffer_index_array);
61 static struct orangefs_bufmap *orangefs_bufmap_ref(void)
63 struct orangefs_bufmap *bufmap = NULL;
65 spin_lock(&orangefs_bufmap_lock);
66 if (__orangefs_bufmap) {
67 bufmap = __orangefs_bufmap;
68 atomic_inc(&bufmap->refcnt);
70 spin_unlock(&orangefs_bufmap_lock);
74 static void orangefs_bufmap_unref(struct orangefs_bufmap *bufmap)
76 if (atomic_dec_and_lock(&bufmap->refcnt, &orangefs_bufmap_lock)) {
77 __orangefs_bufmap = NULL;
78 spin_unlock(&orangefs_bufmap_lock);
80 orangefs_bufmap_unmap(bufmap);
81 orangefs_bufmap_free(bufmap);
86 * XXX: Can the size and shift change while the caller gives up the
87 * XXX: lock between calling this and doing something useful?
90 int orangefs_bufmap_size_query(void)
92 struct orangefs_bufmap *bufmap;
94 bufmap = orangefs_bufmap_ref();
96 size = bufmap->desc_size;
97 orangefs_bufmap_unref(bufmap);
102 int orangefs_bufmap_shift_query(void)
104 struct orangefs_bufmap *bufmap;
106 bufmap = orangefs_bufmap_ref();
108 shift = bufmap->desc_shift;
109 orangefs_bufmap_unref(bufmap);
114 static DECLARE_WAIT_QUEUE_HEAD(bufmap_waitq);
115 static DECLARE_WAIT_QUEUE_HEAD(readdir_waitq);
118 * orangefs_get_bufmap_init
120 * If bufmap_init is 1, then the shared memory system, including the
121 * buffer_index_array, is available. Otherwise, it is not.
123 * returns the value of bufmap_init
125 int orangefs_get_bufmap_init(void)
127 return __orangefs_bufmap ? 1 : 0;
131 static struct orangefs_bufmap *
132 orangefs_bufmap_alloc(struct ORANGEFS_dev_map_desc *user_desc)
134 struct orangefs_bufmap *bufmap;
136 bufmap = kzalloc(sizeof(*bufmap), GFP_KERNEL);
140 atomic_set(&bufmap->refcnt, 1);
141 bufmap->total_size = user_desc->total_size;
142 bufmap->desc_count = user_desc->count;
143 bufmap->desc_size = user_desc->size;
144 bufmap->desc_shift = ilog2(bufmap->desc_size);
146 spin_lock_init(&bufmap->buffer_index_lock);
147 bufmap->buffer_index_array =
148 kcalloc(bufmap->desc_count, sizeof(int), GFP_KERNEL);
149 if (!bufmap->buffer_index_array) {
150 gossip_err("orangefs: could not allocate %d buffer indices\n",
152 goto out_free_bufmap;
154 spin_lock_init(&bufmap->readdir_index_lock);
157 kcalloc(bufmap->desc_count, sizeof(struct orangefs_bufmap_desc),
159 if (!bufmap->desc_array) {
160 gossip_err("orangefs: could not allocate %d descriptors\n",
162 goto out_free_index_array;
165 bufmap->page_count = bufmap->total_size / PAGE_SIZE;
167 /* allocate storage to track our page mappings */
169 kcalloc(bufmap->page_count, sizeof(struct page *), GFP_KERNEL);
170 if (!bufmap->page_array)
171 goto out_free_desc_array;
176 kfree(bufmap->desc_array);
177 out_free_index_array:
178 kfree(bufmap->buffer_index_array);
186 orangefs_bufmap_map(struct orangefs_bufmap *bufmap,
187 struct ORANGEFS_dev_map_desc *user_desc)
189 int pages_per_desc = bufmap->desc_size / PAGE_SIZE;
190 int offset = 0, ret, i;
193 ret = get_user_pages_fast((unsigned long)user_desc->ptr,
194 bufmap->page_count, 1, bufmap->page_array);
199 if (ret != bufmap->page_count) {
200 gossip_err("orangefs error: asked for %d pages, only got %d.\n",
201 bufmap->page_count, ret);
203 for (i = 0; i < ret; i++) {
204 SetPageError(bufmap->page_array[i]);
205 page_cache_release(bufmap->page_array[i]);
211 * ideally we want to get kernel space pointers for each page, but
212 * we can't kmap that many pages at once if highmem is being used.
213 * so instead, we just kmap/kunmap the page address each time the
216 for (i = 0; i < bufmap->page_count; i++)
217 flush_dcache_page(bufmap->page_array[i]);
219 /* build a list of available descriptors */
220 for (offset = 0, i = 0; i < bufmap->desc_count; i++) {
221 bufmap->desc_array[i].page_array = &bufmap->page_array[offset];
222 bufmap->desc_array[i].array_count = pages_per_desc;
223 bufmap->desc_array[i].uaddr =
224 (user_desc->ptr + (i * pages_per_desc * PAGE_SIZE));
225 offset += pages_per_desc;
232 * orangefs_bufmap_initialize()
234 * initializes the mapped buffer interface
236 * returns 0 on success, -errno on failure
238 int orangefs_bufmap_initialize(struct ORANGEFS_dev_map_desc *user_desc)
240 struct orangefs_bufmap *bufmap;
243 gossip_debug(GOSSIP_BUFMAP_DEBUG,
244 "orangefs_bufmap_initialize: called (ptr ("
245 "%p) sz (%d) cnt(%d).\n",
251 * sanity check alignment and size of buffer that caller wants to
254 if (PAGE_ALIGN((unsigned long)user_desc->ptr) !=
255 (unsigned long)user_desc->ptr) {
256 gossip_err("orangefs error: memory alignment (front). %p\n",
261 if (PAGE_ALIGN(((unsigned long)user_desc->ptr + user_desc->total_size))
262 != (unsigned long)(user_desc->ptr + user_desc->total_size)) {
263 gossip_err("orangefs error: memory alignment (back).(%p + %d)\n",
265 user_desc->total_size);
269 if (user_desc->total_size != (user_desc->size * user_desc->count)) {
270 gossip_err("orangefs error: user provided an oddly sized buffer: (%d, %d, %d)\n",
271 user_desc->total_size,
277 if ((user_desc->size % PAGE_SIZE) != 0) {
278 gossip_err("orangefs error: bufmap size not page size divisible (%d).\n",
284 bufmap = orangefs_bufmap_alloc(user_desc);
288 ret = orangefs_bufmap_map(bufmap, user_desc);
290 goto out_free_bufmap;
293 spin_lock(&orangefs_bufmap_lock);
294 if (__orangefs_bufmap) {
295 spin_unlock(&orangefs_bufmap_lock);
296 gossip_err("orangefs: error: bufmap already initialized.\n");
298 goto out_unmap_bufmap;
300 __orangefs_bufmap = bufmap;
301 spin_unlock(&orangefs_bufmap_lock);
304 * If there are operations in orangefs_bufmap_init_waitq, wake them up.
305 * This scenario occurs when the client-core is restarted and I/O
306 * requests in the in-progress or waiting tables are restarted. I/O
307 * requests cannot be restarted until the shared memory system is
308 * completely re-initialized, so we put the I/O requests in this
309 * waitq until initialization has completed. NOTE: the I/O requests
310 * are also on a timer, so they don't wait forever just in case the
311 * client-core doesn't come back up.
313 wake_up_interruptible(&orangefs_bufmap_init_waitq);
315 gossip_debug(GOSSIP_BUFMAP_DEBUG,
316 "orangefs_bufmap_initialize: exiting normally\n");
320 orangefs_bufmap_unmap(bufmap);
322 orangefs_bufmap_free(bufmap);
328 * orangefs_bufmap_finalize()
330 * shuts down the mapped buffer interface and releases any resources
335 void orangefs_bufmap_finalize(void)
337 gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs_bufmap_finalize: called\n");
338 BUG_ON(!__orangefs_bufmap);
339 orangefs_bufmap_unref(__orangefs_bufmap);
340 gossip_debug(GOSSIP_BUFMAP_DEBUG,
341 "orangefs_bufmap_finalize: exiting normally\n");
347 spinlock_t *slot_lock;
348 wait_queue_head_t *slot_wq;
351 static int wait_for_a_slot(struct slot_args *slargs, int *buffer_index)
355 DEFINE_WAIT(wait_entry);
359 * check for available desc, slot_lock is the appropriate
362 spin_lock(slargs->slot_lock);
363 prepare_to_wait_exclusive(slargs->slot_wq,
366 for (i = 0; i < slargs->slot_count; i++)
367 if (slargs->slot_array[i] == 0) {
368 slargs->slot_array[i] = 1;
373 spin_unlock(slargs->slot_lock);
375 /* if we acquired a buffer, then break out of while */
379 if (!signal_pending(current)) {
380 gossip_debug(GOSSIP_BUFMAP_DEBUG,
381 "[BUFMAP]: waiting %d "
382 "seconds for a slot\n",
384 if (!schedule_timeout(slot_timeout_secs * HZ)) {
385 gossip_debug(GOSSIP_BUFMAP_DEBUG,
386 "*** wait_for_a_slot timed out\n");
390 gossip_debug(GOSSIP_BUFMAP_DEBUG,
391 "[BUFMAP]: woken up by a slot becoming available.\n");
395 gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs: %s interrupted.\n",
401 spin_lock(slargs->slot_lock);
402 finish_wait(slargs->slot_wq, &wait_entry);
403 spin_unlock(slargs->slot_lock);
407 static void put_back_slot(struct slot_args *slargs, int buffer_index)
409 /* slot_lock is the appropriate index_lock */
410 spin_lock(slargs->slot_lock);
411 if (buffer_index < 0 || buffer_index >= slargs->slot_count) {
412 spin_unlock(slargs->slot_lock);
416 /* put the desc back on the queue */
417 slargs->slot_array[buffer_index] = 0;
418 spin_unlock(slargs->slot_lock);
420 /* wake up anyone who may be sleeping on the queue */
421 wake_up_interruptible(slargs->slot_wq);
425 * orangefs_bufmap_get()
427 * gets a free mapped buffer descriptor, will sleep until one becomes
428 * available if necessary
430 * returns 0 on success, -errno on failure
432 int orangefs_bufmap_get(struct orangefs_bufmap **mapp, int *buffer_index)
434 struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
435 struct slot_args slargs;
439 gossip_err("orangefs: please confirm that pvfs2-client daemon is running.\n");
443 slargs.slot_count = bufmap->desc_count;
444 slargs.slot_array = bufmap->buffer_index_array;
445 slargs.slot_lock = &bufmap->buffer_index_lock;
446 slargs.slot_wq = &bufmap_waitq;
447 ret = wait_for_a_slot(&slargs, buffer_index);
449 orangefs_bufmap_unref(bufmap);
455 * orangefs_bufmap_put()
457 * returns a mapped buffer descriptor to the collection
461 void orangefs_bufmap_put(int buffer_index)
463 struct slot_args slargs;
464 struct orangefs_bufmap *bufmap = __orangefs_bufmap;
466 slargs.slot_count = bufmap->desc_count;
467 slargs.slot_array = bufmap->buffer_index_array;
468 slargs.slot_lock = &bufmap->buffer_index_lock;
469 slargs.slot_wq = &bufmap_waitq;
470 put_back_slot(&slargs, buffer_index);
471 orangefs_bufmap_unref(bufmap);
475 * orangefs_readdir_index_get()
477 * gets a free descriptor, will sleep until one becomes
478 * available if necessary.
479 * Although the readdir buffers are not mapped into kernel space
480 * we could do that at a later point of time. Regardless, these
481 * indices are used by the client-core.
483 * returns 0 on success, -errno on failure
485 int orangefs_readdir_index_get(struct orangefs_bufmap **mapp, int *buffer_index)
487 struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
488 struct slot_args slargs;
492 gossip_err("orangefs: please confirm that pvfs2-client daemon is running.\n");
496 slargs.slot_count = ORANGEFS_READDIR_DEFAULT_DESC_COUNT;
497 slargs.slot_array = bufmap->readdir_index_array;
498 slargs.slot_lock = &bufmap->readdir_index_lock;
499 slargs.slot_wq = &readdir_waitq;
500 ret = wait_for_a_slot(&slargs, buffer_index);
502 orangefs_bufmap_unref(bufmap);
507 void orangefs_readdir_index_put(struct orangefs_bufmap *bufmap, int buffer_index)
509 struct slot_args slargs;
511 slargs.slot_count = ORANGEFS_READDIR_DEFAULT_DESC_COUNT;
512 slargs.slot_array = bufmap->readdir_index_array;
513 slargs.slot_lock = &bufmap->readdir_index_lock;
514 slargs.slot_wq = &readdir_waitq;
515 put_back_slot(&slargs, buffer_index);
516 orangefs_bufmap_unref(bufmap);
520 * we've been handed an iovec, we need to copy it to
521 * the shared memory descriptor at "buffer_index".
523 int orangefs_bufmap_copy_from_iovec(struct orangefs_bufmap *bufmap,
524 struct iov_iter *iter,
528 struct orangefs_bufmap_desc *to = &bufmap->desc_array[buffer_index];
531 gossip_debug(GOSSIP_BUFMAP_DEBUG,
532 "%s: buffer_index:%d: size:%zu:\n",
533 __func__, buffer_index, size);
536 for (i = 0; size; i++) {
537 struct page *page = to->page_array[i];
541 n = copy_page_from_iter(page, 0, n, iter);
551 * we've been handed an iovec, we need to fill it from
552 * the shared memory descriptor at "buffer_index".
554 int orangefs_bufmap_copy_to_iovec(struct orangefs_bufmap *bufmap,
555 struct iov_iter *iter,
559 struct orangefs_bufmap_desc *from = &bufmap->desc_array[buffer_index];
562 gossip_debug(GOSSIP_BUFMAP_DEBUG,
563 "%s: buffer_index:%d: size:%zu:\n",
564 __func__, buffer_index, size);
567 for (i = 0; size; i++) {
568 struct page *page = from->page_array[i];
572 n = copy_page_to_iter(page, 0, n, iter);