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