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-rw-r--r--fs/orangefs/orangefs-bufmap.c539
1 files changed, 539 insertions, 0 deletions
diff --git a/fs/orangefs/orangefs-bufmap.c b/fs/orangefs/orangefs-bufmap.c
new file mode 100644
index 000000000..6d20b1b3a
--- /dev/null
+++ b/fs/orangefs/orangefs-bufmap.c
@@ -0,0 +1,539 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+
+struct slot_map {
+ int c;
+ wait_queue_head_t q;
+ int count;
+ unsigned long *map;
+};
+
+static struct slot_map rw_map = {
+ .c = -1,
+ .q = __WAIT_QUEUE_HEAD_INITIALIZER(rw_map.q)
+};
+static struct slot_map readdir_map = {
+ .c = -1,
+ .q = __WAIT_QUEUE_HEAD_INITIALIZER(readdir_map.q)
+};
+
+
+static void install(struct slot_map *m, int count, unsigned long *map)
+{
+ spin_lock(&m->q.lock);
+ m->c = m->count = count;
+ m->map = map;
+ wake_up_all_locked(&m->q);
+ spin_unlock(&m->q.lock);
+}
+
+static void mark_killed(struct slot_map *m)
+{
+ spin_lock(&m->q.lock);
+ m->c -= m->count + 1;
+ spin_unlock(&m->q.lock);
+}
+
+static void run_down(struct slot_map *m)
+{
+ DEFINE_WAIT(wait);
+ spin_lock(&m->q.lock);
+ if (m->c != -1) {
+ for (;;) {
+ if (likely(list_empty(&wait.entry)))
+ __add_wait_queue_entry_tail(&m->q, &wait);
+ set_current_state(TASK_UNINTERRUPTIBLE);
+
+ if (m->c == -1)
+ break;
+
+ spin_unlock(&m->q.lock);
+ schedule();
+ spin_lock(&m->q.lock);
+ }
+ __remove_wait_queue(&m->q, &wait);
+ __set_current_state(TASK_RUNNING);
+ }
+ m->map = NULL;
+ spin_unlock(&m->q.lock);
+}
+
+static void put(struct slot_map *m, int slot)
+{
+ int v;
+ spin_lock(&m->q.lock);
+ __clear_bit(slot, m->map);
+ v = ++m->c;
+ if (v > 0)
+ wake_up_locked(&m->q);
+ if (unlikely(v == -1)) /* finished dying */
+ wake_up_all_locked(&m->q);
+ spin_unlock(&m->q.lock);
+}
+
+static int wait_for_free(struct slot_map *m)
+{
+ long left = slot_timeout_secs * HZ;
+ DEFINE_WAIT(wait);
+
+ do {
+ long n = left, t;
+ if (likely(list_empty(&wait.entry)))
+ __add_wait_queue_entry_tail_exclusive(&m->q, &wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (m->c > 0)
+ break;
+
+ if (m->c < 0) {
+ /* we are waiting for map to be installed */
+ /* it would better be there soon, or we go away */
+ if (n > ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS * HZ)
+ n = ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS * HZ;
+ }
+ spin_unlock(&m->q.lock);
+ t = schedule_timeout(n);
+ spin_lock(&m->q.lock);
+ if (unlikely(!t) && n != left && m->c < 0)
+ left = t;
+ else
+ left = t + (left - n);
+ if (unlikely(signal_pending(current)))
+ left = -EINTR;
+ } while (left > 0);
+
+ if (!list_empty(&wait.entry))
+ list_del(&wait.entry);
+ else if (left <= 0 && waitqueue_active(&m->q))
+ __wake_up_locked_key(&m->q, TASK_INTERRUPTIBLE, NULL);
+ __set_current_state(TASK_RUNNING);
+
+ if (likely(left > 0))
+ return 0;
+
+ return left < 0 ? -EINTR : -ETIMEDOUT;
+}
+
+static int get(struct slot_map *m)
+{
+ int res = 0;
+ spin_lock(&m->q.lock);
+ if (unlikely(m->c <= 0))
+ res = wait_for_free(m);
+ if (likely(!res)) {
+ m->c--;
+ res = find_first_zero_bit(m->map, m->count);
+ __set_bit(res, m->map);
+ }
+ spin_unlock(&m->q.lock);
+ return res;
+}
+
+/* used to describe mapped buffers */
+struct orangefs_bufmap_desc {
+ void __user *uaddr; /* user space address pointer */
+ struct page **page_array; /* array of mapped pages */
+ int array_count; /* size of above arrays */
+ struct list_head list_link;
+};
+
+static struct orangefs_bufmap {
+ int desc_size;
+ int desc_shift;
+ int desc_count;
+ int total_size;
+ int page_count;
+
+ struct page **page_array;
+ struct orangefs_bufmap_desc *desc_array;
+
+ /* array to track usage of buffer descriptors */
+ unsigned long *buffer_index_array;
+
+ /* array to track usage of buffer descriptors for readdir */
+#define N DIV_ROUND_UP(ORANGEFS_READDIR_DEFAULT_DESC_COUNT, BITS_PER_LONG)
+ unsigned long readdir_index_array[N];
+#undef N
+} *__orangefs_bufmap;
+
+static DEFINE_SPINLOCK(orangefs_bufmap_lock);
+
+static void
+orangefs_bufmap_unmap(struct orangefs_bufmap *bufmap)
+{
+ int i;
+
+ for (i = 0; i < bufmap->page_count; i++)
+ put_page(bufmap->page_array[i]);
+}
+
+static void
+orangefs_bufmap_free(struct orangefs_bufmap *bufmap)
+{
+ kfree(bufmap->page_array);
+ kfree(bufmap->desc_array);
+ bitmap_free(bufmap->buffer_index_array);
+ kfree(bufmap);
+}
+
+/*
+ * XXX: Can the size and shift change while the caller gives up the
+ * XXX: lock between calling this and doing something useful?
+ */
+
+int orangefs_bufmap_size_query(void)
+{
+ struct orangefs_bufmap *bufmap;
+ int size = 0;
+ spin_lock(&orangefs_bufmap_lock);
+ bufmap = __orangefs_bufmap;
+ if (bufmap)
+ size = bufmap->desc_size;
+ spin_unlock(&orangefs_bufmap_lock);
+ return size;
+}
+
+int orangefs_bufmap_shift_query(void)
+{
+ struct orangefs_bufmap *bufmap;
+ int shift = 0;
+ spin_lock(&orangefs_bufmap_lock);
+ bufmap = __orangefs_bufmap;
+ if (bufmap)
+ shift = bufmap->desc_shift;
+ spin_unlock(&orangefs_bufmap_lock);
+ return shift;
+}
+
+static DECLARE_WAIT_QUEUE_HEAD(bufmap_waitq);
+static DECLARE_WAIT_QUEUE_HEAD(readdir_waitq);
+
+static struct orangefs_bufmap *
+orangefs_bufmap_alloc(struct ORANGEFS_dev_map_desc *user_desc)
+{
+ struct orangefs_bufmap *bufmap;
+
+ bufmap = kzalloc(sizeof(*bufmap), GFP_KERNEL);
+ if (!bufmap)
+ goto out;
+
+ bufmap->total_size = user_desc->total_size;
+ bufmap->desc_count = user_desc->count;
+ bufmap->desc_size = user_desc->size;
+ bufmap->desc_shift = ilog2(bufmap->desc_size);
+
+ bufmap->buffer_index_array = bitmap_zalloc(bufmap->desc_count, GFP_KERNEL);
+ if (!bufmap->buffer_index_array)
+ goto out_free_bufmap;
+
+ bufmap->desc_array =
+ kcalloc(bufmap->desc_count, sizeof(struct orangefs_bufmap_desc),
+ GFP_KERNEL);
+ if (!bufmap->desc_array)
+ goto out_free_index_array;
+
+ bufmap->page_count = bufmap->total_size / PAGE_SIZE;
+
+ /* allocate storage to track our page mappings */
+ bufmap->page_array =
+ kcalloc(bufmap->page_count, sizeof(struct page *), GFP_KERNEL);
+ if (!bufmap->page_array)
+ goto out_free_desc_array;
+
+ return bufmap;
+
+out_free_desc_array:
+ kfree(bufmap->desc_array);
+out_free_index_array:
+ bitmap_free(bufmap->buffer_index_array);
+out_free_bufmap:
+ kfree(bufmap);
+out:
+ return NULL;
+}
+
+static int
+orangefs_bufmap_map(struct orangefs_bufmap *bufmap,
+ struct ORANGEFS_dev_map_desc *user_desc)
+{
+ int pages_per_desc = bufmap->desc_size / PAGE_SIZE;
+ int offset = 0, ret, i;
+
+ /* map the pages */
+ ret = get_user_pages_fast((unsigned long)user_desc->ptr,
+ bufmap->page_count, 1, bufmap->page_array);
+
+ if (ret < 0)
+ return ret;
+
+ if (ret != bufmap->page_count) {
+ gossip_err("orangefs error: asked for %d pages, only got %d.\n",
+ bufmap->page_count, ret);
+
+ for (i = 0; i < ret; i++) {
+ SetPageError(bufmap->page_array[i]);
+ put_page(bufmap->page_array[i]);
+ }
+ return -ENOMEM;
+ }
+
+ /*
+ * ideally we want to get kernel space pointers for each page, but
+ * we can't kmap that many pages at once if highmem is being used.
+ * so instead, we just kmap/kunmap the page address each time the
+ * kaddr is needed.
+ */
+ for (i = 0; i < bufmap->page_count; i++)
+ flush_dcache_page(bufmap->page_array[i]);
+
+ /* build a list of available descriptors */
+ for (offset = 0, i = 0; i < bufmap->desc_count; i++) {
+ bufmap->desc_array[i].page_array = &bufmap->page_array[offset];
+ bufmap->desc_array[i].array_count = pages_per_desc;
+ bufmap->desc_array[i].uaddr =
+ (user_desc->ptr + (i * pages_per_desc * PAGE_SIZE));
+ offset += pages_per_desc;
+ }
+
+ return 0;
+}
+
+/*
+ * orangefs_bufmap_initialize()
+ *
+ * initializes the mapped buffer interface
+ *
+ * returns 0 on success, -errno on failure
+ */
+int orangefs_bufmap_initialize(struct ORANGEFS_dev_map_desc *user_desc)
+{
+ struct orangefs_bufmap *bufmap;
+ int ret = -EINVAL;
+
+ gossip_debug(GOSSIP_BUFMAP_DEBUG,
+ "orangefs_bufmap_initialize: called (ptr ("
+ "%p) sz (%d) cnt(%d).\n",
+ user_desc->ptr,
+ user_desc->size,
+ user_desc->count);
+
+ if (user_desc->total_size < 0 ||
+ user_desc->size < 0 ||
+ user_desc->count < 0)
+ goto out;
+
+ /*
+ * sanity check alignment and size of buffer that caller wants to
+ * work with
+ */
+ if (PAGE_ALIGN((unsigned long)user_desc->ptr) !=
+ (unsigned long)user_desc->ptr) {
+ gossip_err("orangefs error: memory alignment (front). %p\n",
+ user_desc->ptr);
+ goto out;
+ }
+
+ if (PAGE_ALIGN(((unsigned long)user_desc->ptr + user_desc->total_size))
+ != (unsigned long)(user_desc->ptr + user_desc->total_size)) {
+ gossip_err("orangefs error: memory alignment (back).(%p + %d)\n",
+ user_desc->ptr,
+ user_desc->total_size);
+ goto out;
+ }
+
+ if (user_desc->total_size != (user_desc->size * user_desc->count)) {
+ gossip_err("orangefs error: user provided an oddly sized buffer: (%d, %d, %d)\n",
+ user_desc->total_size,
+ user_desc->size,
+ user_desc->count);
+ goto out;
+ }
+
+ if ((user_desc->size % PAGE_SIZE) != 0) {
+ gossip_err("orangefs error: bufmap size not page size divisible (%d).\n",
+ user_desc->size);
+ goto out;
+ }
+
+ ret = -ENOMEM;
+ bufmap = orangefs_bufmap_alloc(user_desc);
+ if (!bufmap)
+ goto out;
+
+ ret = orangefs_bufmap_map(bufmap, user_desc);
+ if (ret)
+ goto out_free_bufmap;
+
+
+ spin_lock(&orangefs_bufmap_lock);
+ if (__orangefs_bufmap) {
+ spin_unlock(&orangefs_bufmap_lock);
+ gossip_err("orangefs: error: bufmap already initialized.\n");
+ ret = -EINVAL;
+ goto out_unmap_bufmap;
+ }
+ __orangefs_bufmap = bufmap;
+ install(&rw_map,
+ bufmap->desc_count,
+ bufmap->buffer_index_array);
+ install(&readdir_map,
+ ORANGEFS_READDIR_DEFAULT_DESC_COUNT,
+ bufmap->readdir_index_array);
+ spin_unlock(&orangefs_bufmap_lock);
+
+ gossip_debug(GOSSIP_BUFMAP_DEBUG,
+ "orangefs_bufmap_initialize: exiting normally\n");
+ return 0;
+
+out_unmap_bufmap:
+ orangefs_bufmap_unmap(bufmap);
+out_free_bufmap:
+ orangefs_bufmap_free(bufmap);
+out:
+ return ret;
+}
+
+/*
+ * orangefs_bufmap_finalize()
+ *
+ * shuts down the mapped buffer interface and releases any resources
+ * associated with it
+ *
+ * no return value
+ */
+void orangefs_bufmap_finalize(void)
+{
+ struct orangefs_bufmap *bufmap = __orangefs_bufmap;
+ if (!bufmap)
+ return;
+ gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs_bufmap_finalize: called\n");
+ mark_killed(&rw_map);
+ mark_killed(&readdir_map);
+ gossip_debug(GOSSIP_BUFMAP_DEBUG,
+ "orangefs_bufmap_finalize: exiting normally\n");
+}
+
+void orangefs_bufmap_run_down(void)
+{
+ struct orangefs_bufmap *bufmap = __orangefs_bufmap;
+ if (!bufmap)
+ return;
+ run_down(&rw_map);
+ run_down(&readdir_map);
+ spin_lock(&orangefs_bufmap_lock);
+ __orangefs_bufmap = NULL;
+ spin_unlock(&orangefs_bufmap_lock);
+ orangefs_bufmap_unmap(bufmap);
+ orangefs_bufmap_free(bufmap);
+}
+
+/*
+ * orangefs_bufmap_get()
+ *
+ * gets a free mapped buffer descriptor, will sleep until one becomes
+ * available if necessary
+ *
+ * returns slot on success, -errno on failure
+ */
+int orangefs_bufmap_get(void)
+{
+ return get(&rw_map);
+}
+
+/*
+ * orangefs_bufmap_put()
+ *
+ * returns a mapped buffer descriptor to the collection
+ *
+ * no return value
+ */
+void orangefs_bufmap_put(int buffer_index)
+{
+ put(&rw_map, buffer_index);
+}
+
+/*
+ * orangefs_readdir_index_get()
+ *
+ * gets a free descriptor, will sleep until one becomes
+ * available if necessary.
+ * Although the readdir buffers are not mapped into kernel space
+ * we could do that at a later point of time. Regardless, these
+ * indices are used by the client-core.
+ *
+ * returns slot on success, -errno on failure
+ */
+int orangefs_readdir_index_get(void)
+{
+ return get(&readdir_map);
+}
+
+void orangefs_readdir_index_put(int buffer_index)
+{
+ put(&readdir_map, buffer_index);
+}
+
+/*
+ * we've been handed an iovec, we need to copy it to
+ * the shared memory descriptor at "buffer_index".
+ */
+int orangefs_bufmap_copy_from_iovec(struct iov_iter *iter,
+ int buffer_index,
+ size_t size)
+{
+ struct orangefs_bufmap_desc *to;
+ int i;
+
+ gossip_debug(GOSSIP_BUFMAP_DEBUG,
+ "%s: buffer_index:%d: size:%zu:\n",
+ __func__, buffer_index, size);
+
+ to = &__orangefs_bufmap->desc_array[buffer_index];
+ for (i = 0; size; i++) {
+ struct page *page = to->page_array[i];
+ size_t n = size;
+ if (n > PAGE_SIZE)
+ n = PAGE_SIZE;
+ if (copy_page_from_iter(page, 0, n, iter) != n)
+ return -EFAULT;
+ size -= n;
+ }
+ return 0;
+}
+
+/*
+ * we've been handed an iovec, we need to fill it from
+ * the shared memory descriptor at "buffer_index".
+ */
+int orangefs_bufmap_copy_to_iovec(struct iov_iter *iter,
+ int buffer_index,
+ size_t size)
+{
+ struct orangefs_bufmap_desc *from;
+ int i;
+
+ from = &__orangefs_bufmap->desc_array[buffer_index];
+ gossip_debug(GOSSIP_BUFMAP_DEBUG,
+ "%s: buffer_index:%d: size:%zu:\n",
+ __func__, buffer_index, size);
+
+
+ for (i = 0; size; i++) {
+ struct page *page = from->page_array[i];
+ size_t n = size;
+ if (n > PAGE_SIZE)
+ n = PAGE_SIZE;
+ n = copy_page_to_iter(page, 0, n, iter);
+ if (!n)
+ return -EFAULT;
+ size -= n;
+ }
+ return 0;
+}