1 files changed, 558 insertions, 0 deletions

diff --git a/fs/orangefs/orangefs-bufmap.c b/fs/orangefs/orangefs-bufmap.c
new file mode 100644
index 0000000..c5368d8
--- /dev/null
+++ b/fs/orangefs/orangefs-bufmap.c
@@ -0,0 +1,558 @@
+/*
+ * (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"
+
+DECLARE_WAIT_QUEUE_HEAD(orangefs_bufmap_init_waitq);
+
+static struct orangefs_bufmap {
+	atomic_t refcnt;
+
+	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 */
+	int *buffer_index_array;
+	spinlock_t buffer_index_lock;
+
+	/* array to track usage of buffer descriptors for readdir */
+	int readdir_index_array[ORANGEFS_READDIR_DEFAULT_DESC_COUNT];
+	spinlock_t readdir_index_lock;
+} *__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++)
+		page_cache_release(bufmap->page_array[i]);
+}
+
+static void
+orangefs_bufmap_free(struct orangefs_bufmap *bufmap)
+{
+	kfree(bufmap->page_array);
+	kfree(bufmap->desc_array);
+	kfree(bufmap->buffer_index_array);
+	kfree(bufmap);
+}
+
+struct orangefs_bufmap *orangefs_bufmap_ref(void)
+{
+	struct orangefs_bufmap *bufmap = NULL;
+
+	spin_lock(&orangefs_bufmap_lock);
+	if (__orangefs_bufmap) {
+		bufmap = __orangefs_bufmap;
+		atomic_inc(&bufmap->refcnt);
+	}
+	spin_unlock(&orangefs_bufmap_lock);
+	return bufmap;
+}
+
+void orangefs_bufmap_unref(struct orangefs_bufmap *bufmap)
+{
+	if (atomic_dec_and_lock(&bufmap->refcnt, &orangefs_bufmap_lock)) {
+		__orangefs_bufmap = NULL;
+		spin_unlock(&orangefs_bufmap_lock);
+
+		orangefs_bufmap_unmap(bufmap);
+		orangefs_bufmap_free(bufmap);
+	}
+}
+
+inline int orangefs_bufmap_size_query(void)
+{
+	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
+	int size = bufmap ? bufmap->desc_size : 0;
+
+	orangefs_bufmap_unref(bufmap);
+	return size;
+}
+
+inline int orangefs_bufmap_shift_query(void)
+{
+	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
+	int shift = bufmap ? bufmap->desc_shift : 0;
+
+	orangefs_bufmap_unref(bufmap);
+	return shift;
+}
+
+static DECLARE_WAIT_QUEUE_HEAD(bufmap_waitq);
+static DECLARE_WAIT_QUEUE_HEAD(readdir_waitq);
+
+/*
+ * get_bufmap_init
+ *
+ * If bufmap_init is 1, then the shared memory system, including the
+ * buffer_index_array, is available.  Otherwise, it is not.
+ *
+ * returns the value of bufmap_init
+ */
+int get_bufmap_init(void)
+{
+	return __orangefs_bufmap ? 1 : 0;
+}
+
+
+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;
+
+	atomic_set(&bufmap->refcnt, 1);
+	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);
+
+	spin_lock_init(&bufmap->buffer_index_lock);
+	bufmap->buffer_index_array =
+		kcalloc(bufmap->desc_count, sizeof(int), GFP_KERNEL);
+	if (!bufmap->buffer_index_array) {
+		gossip_err("orangefs: could not allocate %d buffer indices\n",
+				bufmap->desc_count);
+		goto out_free_bufmap;
+	}
+	spin_lock_init(&bufmap->readdir_index_lock);
+
+	bufmap->desc_array =
+		kcalloc(bufmap->desc_count, sizeof(struct orangefs_bufmap_desc),
+			GFP_KERNEL);
+	if (!bufmap->desc_array) {
+		gossip_err("orangefs: could not allocate %d descriptors\n",
+				bufmap->desc_count);
+		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:
+	kfree(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]);
+			page_cache_release(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);
+
+	/*
+	 * 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 = -EALREADY;
+		goto out_unmap_bufmap;
+	}
+	__orangefs_bufmap = bufmap;
+	spin_unlock(&orangefs_bufmap_lock);
+
+	/*
+	 * If there are operations in orangefs_bufmap_init_waitq, wake them up.
+	 * This scenario occurs when the client-core is restarted and I/O
+	 * requests in the in-progress or waiting tables are restarted.  I/O
+	 * requests cannot be restarted until the shared memory system is
+	 * completely re-initialized, so we put the I/O requests in this
+	 * waitq until initialization has completed.  NOTE:  the I/O requests
+	 * are also on a timer, so they don't wait forever just in case the
+	 * client-core doesn't come back up.
+	 */
+	wake_up_interruptible(&orangefs_bufmap_init_waitq);
+
+	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)
+{
+	gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs_bufmap_finalize: called\n");
+	BUG_ON(!__orangefs_bufmap);
+	orangefs_bufmap_unref(__orangefs_bufmap);
+	gossip_debug(GOSSIP_BUFMAP_DEBUG,
+		     "orangefs_bufmap_finalize: exiting normally\n");
+}
+
+struct slot_args {
+	int slot_count;
+	int *slot_array;
+	spinlock_t *slot_lock;
+	wait_queue_head_t *slot_wq;
+};
+
+static int wait_for_a_slot(struct slot_args *slargs, int *buffer_index)
+{
+	int ret = -1;
+	int i = 0;
+	DECLARE_WAITQUEUE(my_wait, current);
+
+
+	add_wait_queue_exclusive(slargs->slot_wq, &my_wait);
+
+	while (1) {
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		/*
+		 * check for available desc, slot_lock is the appropriate
+		 * index_lock
+		 */
+		spin_lock(slargs->slot_lock);
+		for (i = 0; i < slargs->slot_count; i++)
+			if (slargs->slot_array[i] == 0) {
+				slargs->slot_array[i] = 1;
+				*buffer_index = i;
+				ret = 0;
+				break;
+			}
+		spin_unlock(slargs->slot_lock);
+
+		/* if we acquired a buffer, then break out of while */
+		if (ret == 0)
+			break;
+
+		if (!signal_pending(current)) {
+			int timeout =
+			    MSECS_TO_JIFFIES(1000 * slot_timeout_secs);
+			gossip_debug(GOSSIP_BUFMAP_DEBUG,
+				     "[BUFMAP]: waiting %d "
+				     "seconds for a slot\n",
+				     slot_timeout_secs);
+			if (!schedule_timeout(timeout)) {
+				gossip_debug(GOSSIP_BUFMAP_DEBUG,
+					     "*** wait_for_a_slot timed out\n");
+				ret = -ETIMEDOUT;
+				break;
+			}
+			gossip_debug(GOSSIP_BUFMAP_DEBUG,
+			  "[BUFMAP]: woken up by a slot becoming available.\n");
+			continue;
+		}
+
+		gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs: %s interrupted.\n",
+			     __func__);
+		ret = -EINTR;
+		break;
+	}
+
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(slargs->slot_wq, &my_wait);
+	return ret;
+}
+
+static void put_back_slot(struct slot_args *slargs, int buffer_index)
+{
+	/* slot_lock is the appropriate index_lock */
+	spin_lock(slargs->slot_lock);
+	if (buffer_index < 0 || buffer_index >= slargs->slot_count) {
+		spin_unlock(slargs->slot_lock);
+		return;
+	}
+
+	/* put the desc back on the queue */
+	slargs->slot_array[buffer_index] = 0;
+	spin_unlock(slargs->slot_lock);
+
+	/* wake up anyone who may be sleeping on the queue */
+	wake_up_interruptible(slargs->slot_wq);
+}
+
+/*
+ * orangefs_bufmap_get()
+ *
+ * gets a free mapped buffer descriptor, will sleep until one becomes
+ * available if necessary
+ *
+ * returns 0 on success, -errno on failure
+ */
+int orangefs_bufmap_get(struct orangefs_bufmap **mapp, int *buffer_index)
+{
+	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
+	struct slot_args slargs;
+	int ret;
+
+	if (!bufmap) {
+		gossip_err("orangefs: please confirm that pvfs2-client daemon is running.\n");
+		return -EIO;
+	}
+
+	slargs.slot_count = bufmap->desc_count;
+	slargs.slot_array = bufmap->buffer_index_array;
+	slargs.slot_lock = &bufmap->buffer_index_lock;
+	slargs.slot_wq = &bufmap_waitq;
+	ret = wait_for_a_slot(&slargs, buffer_index);
+	if (ret)
+		orangefs_bufmap_unref(bufmap);
+	*mapp = bufmap;
+	return ret;
+}
+
+/*
+ * orangefs_bufmap_put()
+ *
+ * returns a mapped buffer descriptor to the collection
+ *
+ * no return value
+ */
+void orangefs_bufmap_put(struct orangefs_bufmap *bufmap, int buffer_index)
+{
+	struct slot_args slargs;
+
+	slargs.slot_count = bufmap->desc_count;
+	slargs.slot_array = bufmap->buffer_index_array;
+	slargs.slot_lock = &bufmap->buffer_index_lock;
+	slargs.slot_wq = &bufmap_waitq;
+	put_back_slot(&slargs, buffer_index);
+	orangefs_bufmap_unref(bufmap);
+}
+
+/*
+ * 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 0 on success, -errno on failure
+ */
+int readdir_index_get(struct orangefs_bufmap **mapp, int *buffer_index)
+{
+	struct orangefs_bufmap *bufmap = orangefs_bufmap_ref();
+	struct slot_args slargs;
+	int ret;
+
+	if (!bufmap) {
+		gossip_err("orangefs: please confirm that pvfs2-client daemon is running.\n");
+		return -EIO;
+	}
+
+	slargs.slot_count = ORANGEFS_READDIR_DEFAULT_DESC_COUNT;
+	slargs.slot_array = bufmap->readdir_index_array;
+	slargs.slot_lock = &bufmap->readdir_index_lock;
+	slargs.slot_wq = &readdir_waitq;
+	ret = wait_for_a_slot(&slargs, buffer_index);
+	if (ret)
+		orangefs_bufmap_unref(bufmap);
+	*mapp = bufmap;
+	return ret;
+}
+
+void readdir_index_put(struct orangefs_bufmap *bufmap, int buffer_index)
+{
+	struct slot_args slargs;
+
+	slargs.slot_count = ORANGEFS_READDIR_DEFAULT_DESC_COUNT;
+	slargs.slot_array = bufmap->readdir_index_array;
+	slargs.slot_lock = &bufmap->readdir_index_lock;
+	slargs.slot_wq = &readdir_waitq;
+	put_back_slot(&slargs, buffer_index);
+	orangefs_bufmap_unref(bufmap);
+}
+
+int orangefs_bufmap_copy_from_iovec(struct orangefs_bufmap *bufmap,
+				struct iov_iter *iter,
+				int buffer_index,
+				size_t size)
+{
+	struct orangefs_bufmap_desc *to = &bufmap->desc_array[buffer_index];
+	int i;
+
+	gossip_debug(GOSSIP_BUFMAP_DEBUG,
+		     "%s: buffer_index:%d: size:%zu:\n",
+		     __func__, buffer_index, size);
+
+
+	for (i = 0; size; i++) {
+		struct page *page = to->page_array[i];
+		size_t n = size;
+		if (n > PAGE_SIZE)
+			n = PAGE_SIZE;
+		n = copy_page_from_iter(page, 0, n, iter);
+		if (!n)
+			return -EFAULT;
+		size -= n;
+	}
+	return 0;
+
+}
+
+/*
+ * Iterate through the array of pages containing the bytes from
+ * a file being read.
+ *
+ */
+int orangefs_bufmap_copy_to_iovec(struct orangefs_bufmap *bufmap,
+				    struct iov_iter *iter,
+				    int buffer_index,
+				    size_t size)
+{
+	struct orangefs_bufmap_desc *from = &bufmap->desc_array[buffer_index];
+	int i;
+
+	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;
+}