---
drivers/md/persistent-data/dm-block-manager.h | 2
drivers/md/persistent-data/dm-bufio.c | 1498 --------------------------
drivers/md/persistent-data/dm-bufio.h | 110 -
3 files changed, 1 insertion(+), 1609 deletions(-)
Index: linux-3.1-rc9/drivers/md/persistent-data/dm-block-manager.h
===================================================================
--- linux-3.1-rc9.orig/drivers/md/persistent-data/dm-block-manager.h
+++ linux-3.1-rc9/drivers/md/persistent-data/dm-block-manager.h
@@ -7,7 +7,7 @@
#ifndef _LINUX_DM_BLOCK_MANAGER_H
#define _LINUX_DM_BLOCK_MANAGER_H
-#include "dm-bufio.h"
+#include "../dm-bufio.h"
/*----------------------------------------------------------------*/
Index: linux-3.1-rc9/drivers/md/persistent-data/dm-bufio.c
===================================================================
--- linux-3.1-rc9.orig/drivers/md/persistent-data/dm-bufio.c
+++ /dev/null
@@ -1,1498 +0,0 @@
-/*
- * Copyright (C) 2009-2011 2011 Red Hat, Inc.
- *
- * This file is released under the GPL.
- */
-
-#include "dm-bufio.h"
-
-#include <linux/device-mapper.h>
-#include <linux/dm-io.h>
-#include <linux/slab.h>
-#include <linux/vmalloc.h>
-#include <linux/version.h>
-#include <linux/shrinker.h>
-
-/*
- * Memory management policy:
- * Limit the number of buffers to DM_BUFIO_MEMORY_RATIO of main memory or
- * DM_BUFIO_VMALLOC_RATIO of vmalloc memory (whichever is lower).
- * Always allocate at least DM_BUFIO_MIN_BUFFERS buffers.
- * When there are DM_BUFIO_WRITEBACK_RATIO dirty buffers, start background
- * writeback.
- */
-#define DM_BUFIO_MIN_BUFFERS 8
-#define DM_BUFIO_MEMORY_RATIO 2 / 100
-#define DM_BUFIO_VMALLOC_RATIO 1 / 4
-#define DM_BUFIO_WRITEBACK_RATIO 3 / 4
-
-/* Check buffer ages in this interval (seconds) */
-#define DM_BUFIO_WORK_TIMER 10
-
-/* Free buffers when they are older than this (seconds) */
-#define DM_BUFIO_DEFAULT_AGE 60
-
-/*
- * The number of bvec entries that are embedded directly in the buffer.
- * If the chunk size is larger, dm-io is used to do the io.
- */
-#define DM_BUFIO_INLINE_VECS 16
-
-/*
- * Buffer hash
- */
-#define DM_BUFIO_HASH_BITS 20
-#define DM_BUFIO_HASH(block) ((((block) >> DM_BUFIO_HASH_BITS) ^ (block)) & ((1 << DM_BUFIO_HASH_BITS) - 1))
-
-/*
- * Don't try to use kmem_cache_alloc for blocks larger than this.
- * For explanation, see dm_bufio_alloc_buffer_data below.
- */
-#define DM_BUFIO_BLOCK_SIZE_SLAB_LIMIT (PAGE_SIZE >> 1)
-#define DM_BUFIO_BLOCK_SIZE_GFP_LIMIT (PAGE_SIZE << (MAX_ORDER - 1))
-
-/*
- * dm_buffer->list_mode
- */
-#define LIST_CLEAN 0
-#define LIST_DIRTY 1
-#define LIST_N 2
-
-struct dm_bufio_client {
- /*
- * Linking of buffers:
- * all buffers are linked to cache_hash with their hash_list field.
- * clean buffers that are not being written (B_WRITING not set)
- * are linked to lru[LIST_CLEAN] with their lru_list field.
- * dirty and clean buffers that are being written are linked
- * to lru[LIST_DIRTY] with their lru_list field. When the
- * write finishes, the buffer cannot be immediately
- * relinked (because we are in an interrupt context and
- * relinking requires process context), so some
- * clean-not-writing buffers can be held on dirty_lru too.
- * They are later added to lru in the process context.
- */
- struct mutex lock;
-
- struct list_head lru[LIST_N];
- unsigned long n_buffers[LIST_N];
-
- struct block_device *bdev;
- unsigned block_size;
- unsigned char sectors_per_block_bits;
- unsigned char pages_per_block_bits;
- unsigned char blocks_per_page_bits;
- unsigned aux_size;
- void (*alloc_callback)(struct dm_buffer *);
- void (*write_callback)(struct dm_buffer *);
-
- struct dm_io_client *dm_io;
-
- struct list_head reserved_buffers;
- unsigned need_reserved_buffers;
-
- struct hlist_head *cache_hash;
- wait_queue_head_t free_buffer_wait;
-
- int async_write_error;
-
- struct list_head client_list;
- struct shrinker shrinker;
-};
-
-/*
- * Buffer state bits.
- */
-#define B_READING 0
-#define B_WRITING 1
-#define B_DIRTY 2
-
-/*
- * Describes how the block was allocated:
- * kmem_cache_alloc(), __get_free_pages() or vmalloc().
- * See the comment at dm_bufio_alloc_buffer_data.
- */
-enum data_mode {
- DATA_MODE_SLAB = 0,
- DATA_MODE_GET_FREE_PAGES = 1,
- DATA_MODE_VMALLOC = 2,
- DATA_MODE_LIMIT = 3
-};
-
-struct dm_buffer {
- struct hlist_node hash_list;
- struct list_head lru_list;
- sector_t block;
- void *data;
- enum data_mode data_mode;
- unsigned char list_mode; /* LIST_* */
- unsigned hold_count;
- int read_error;
- int write_error;
- unsigned long state;
- unsigned long last_accessed;
- struct dm_bufio_client *c;
- struct bio bio;
- struct bio_vec bio_vec[DM_BUFIO_INLINE_VECS];
-};
-
-/*----------------------------------------------------------------*/
-
-static struct kmem_cache *dm_bufio_caches[PAGE_SHIFT - SECTOR_SHIFT];
-static char *dm_bufio_cache_names[PAGE_SHIFT - SECTOR_SHIFT];
-static inline int dm_bufio_cache_index(struct dm_bufio_client *c)
-{
- unsigned ret = c->blocks_per_page_bits - 1;
- BUG_ON(ret >= ARRAY_SIZE(dm_bufio_caches));
- return ret;
-}
-#define DM_BUFIO_CACHE(c) (dm_bufio_caches[dm_bufio_cache_index(c)])
-#define DM_BUFIO_CACHE_NAME(c) (dm_bufio_cache_names[dm_bufio_cache_index(c)])
-
-/*----------------------------------------------------------------*/
-
-/* Default cache size --- available memory divided by the ratio */
-static unsigned long dm_bufio_default_cache_size;
-
-/* Total cache size set by the user */
-static unsigned long dm_bufio_cache_size;
-
-/*
- * A copy of dm_bufio_cache_size because dm_bufio_cache_size can change
- * anytime. If it disagrees, the user has changed cache size
- */
-static unsigned long dm_bufio_cache_size_latch;
-
-static DEFINE_SPINLOCK(param_spinlock);
-
-/* Buffers are freed after this timeout */
-static unsigned dm_bufio_max_age = DM_BUFIO_DEFAULT_AGE;
-static unsigned long dm_bufio_peak_allocated;
-static unsigned long dm_bufio_allocated_kmem_cache;
-static unsigned long dm_bufio_allocated_get_free_pages;
-static unsigned long dm_bufio_allocated_vmalloc;
-static unsigned long dm_bufio_current_allocated;
-
-/*----------------------------------------------------------------*/
-
-/* Per-client cache: dm_bufio_cache_size / dm_bufio_client_count */
-static unsigned long dm_bufio_cache_size_per_client;
-
-/* The current number of clients */
-static int dm_bufio_client_count;
-
-/* The list of all clients */
-static LIST_HEAD(dm_bufio_all_clients);
-
-/* This mutex protects dm_bufio_cache_size_latch,
- dm_bufio_cache_size_per_client, dm_bufio_client_count */
-static DEFINE_MUTEX(dm_bufio_clients_lock);
-
-/*----------------------------------------------------------------*/
-
-static void adjust_total_allocated(enum data_mode data_mode, long diff)
-{
- static unsigned long * const class_ptr[DATA_MODE_LIMIT] = {
- &dm_bufio_allocated_kmem_cache,
- &dm_bufio_allocated_get_free_pages,
- &dm_bufio_allocated_vmalloc,
- };
-
- spin_lock(¶m_spinlock);
-
- *class_ptr[data_mode] += diff;
- dm_bufio_current_allocated += diff;
- if (dm_bufio_current_allocated > dm_bufio_peak_allocated)
- dm_bufio_peak_allocated = dm_bufio_current_allocated;
-
- spin_unlock(¶m_spinlock);
-}
-
-/*
- * Change the number of clients and recalculate per-client limit.
- */
-static void __cache_size_refresh(void)
-{
- BUG_ON(!mutex_is_locked(&dm_bufio_clients_lock));
- BUG_ON(dm_bufio_client_count < 0);
- dm_bufio_cache_size_latch = dm_bufio_cache_size;
-
- /*
- * Prevent the compiler from using dm_bufio_cache_size anymore because
- * it can change.
- */
- barrier();
-
- if (!dm_bufio_cache_size_latch) {
- /*
- * If the user uses "0", it means default.
- * Modify dm_bufio_cache_size to report the real used cache
- * size to the user.
- */
- (void)cmpxchg(&dm_bufio_cache_size, 0,
- dm_bufio_default_cache_size);
- dm_bufio_cache_size_latch = dm_bufio_default_cache_size;
- }
- dm_bufio_cache_size_per_client = dm_bufio_cache_size_latch /
- (dm_bufio_client_count ? dm_bufio_client_count : 1);
-}
-
-/*
- * Allocating buffer data.
- *
- * Small buffers are allocated with kmem_cache, to use space optimally.
- *
- * Large buffers:
- * We use get_free_pages or vmalloc, both have their advantages and
- * disadvantages.
- * __get_free_pages can randomly fail, if the memory is fragmented.
- * __vmalloc won't randomly fail, but vmalloc space is limited (it may be
- * as low as 128M) --- so using it for caching is not appropriate.
- * If the allocation may fail we use __get_free_pages. Memory fragmentation
- * won't have fatal effect here, it just causes flushes of some other
- * buffers and more I/O will be performed. Don't use __get_free_pages if
- * it always fails (i.e. order >= MAX_ORDER).
- * If the allocation shouldn't fail we use __vmalloc. This is only for
- * the initial reserve allocation, so there's no risk of wasting
- * all vmalloc space.
- */
-static void *alloc_buffer_data(struct dm_bufio_client *c,
- gfp_t gfp_mask, enum data_mode *data_mode)
-{
- if (c->block_size <= DM_BUFIO_BLOCK_SIZE_SLAB_LIMIT) {
- *data_mode = DATA_MODE_SLAB;
- return kmem_cache_alloc(DM_BUFIO_CACHE(c), gfp_mask);
-
- } else if (c->block_size <= DM_BUFIO_BLOCK_SIZE_GFP_LIMIT &&
- gfp_mask & __GFP_NORETRY) {
- *data_mode = DATA_MODE_GET_FREE_PAGES;
- return (void *)__get_free_pages(gfp_mask,
- c->pages_per_block_bits);
- } else {
- *data_mode = DATA_MODE_VMALLOC;
- return __vmalloc(c->block_size, gfp_mask, PAGE_KERNEL);
- }
-}
-
-/*
- * Free buffer's data.
- */
-static void free_buffer_data(struct dm_bufio_client *c,
- void *data, enum data_mode data_mode)
-{
- switch (data_mode) {
- case DATA_MODE_SLAB:
- kmem_cache_free(DM_BUFIO_CACHE(c), data);
- break;
-
- case DATA_MODE_GET_FREE_PAGES:
- free_pages((unsigned long)data, c->pages_per_block_bits);
- break;
-
- case DATA_MODE_VMALLOC:
- vfree(data);
- break;
-
- default:
- printk(KERN_CRIT "dm_bufio_free_buffer_data: bad data mode: %d",
- data_mode);
- BUG();
- }
-}
-
-/*
- * Allocate buffer and its data.
- */
-static struct dm_buffer *alloc_buffer(struct dm_bufio_client *c, gfp_t gfp_mask)
-{
- struct dm_buffer *b;
- b = kmalloc(sizeof(struct dm_buffer) + c->aux_size, gfp_mask);
- if (!b)
- return NULL;
- b->c = c;
- b->data = alloc_buffer_data(c, gfp_mask, &b->data_mode);
- if (!b->data) {
- kfree(b);
- return NULL;
- }
- adjust_total_allocated(b->data_mode, (long)c->block_size);
- return b;
-}
-
-/*
- * Free buffer and its data.
- */
-static void free_buffer(struct dm_buffer *b)
-{
- struct dm_bufio_client *c = b->c;
- adjust_total_allocated(b->data_mode, -(long)c->block_size);
- free_buffer_data(c, b->data, b->data_mode);
- kfree(b);
-}
-
-/*
- * Link buffer to the hash list and clean or dirty queue.
- */
-static void __link_buffer(struct dm_buffer *b, sector_t block, int dirty)
-{
- struct dm_bufio_client *c = b->c;
- c->n_buffers[dirty]++;
- b->block = block;
- b->list_mode = dirty;
- list_add(&b->lru_list, &c->lru[dirty]);
- hlist_add_head(&b->hash_list, &c->cache_hash[DM_BUFIO_HASH(block)]);
- b->last_accessed = jiffies;
-}
-
-/*
- * Unlink buffer from the hash list and dirty or clean queue.
- */
-static void __unlink_buffer(struct dm_buffer *b)
-{
- struct dm_bufio_client *c = b->c;
- BUG_ON(!c->n_buffers[b->list_mode]);
- c->n_buffers[b->list_mode]--;
- hlist_del(&b->hash_list);
- list_del(&b->lru_list);
-}
-
-/*
- * Place the buffer to the head of dirty or clean LRU queue.
- */
-static void __relink_lru(struct dm_buffer *b, int dirty)
-{
- struct dm_bufio_client *c = b->c;
- BUG_ON(!c->n_buffers[b->list_mode]);
- c->n_buffers[b->list_mode]--;
- c->n_buffers[dirty]++;
- b->list_mode = dirty;
- list_del(&b->lru_list);
- list_add(&b->lru_list, &c->lru[dirty]);
-}
-
-/*----------------------------------------------------------------
- * Submit I/O on the buffer.
- *
- * Bio interface is faster but it has some problems:
- * - the vector list is limited (increasing this limit increases
- * memory-consumption per buffer, so it is not viable)
- * - the memory must be direct-mapped, not vmallocated
- * - the I/O driver can spuriously reject requests if it thinks that
- * the requests are too big for the device or if they cross a
- * controller-defined memory boundary
- *
- * If the buffer is small enough (up to DM_BUFIO_INLINE_VECS pages) and
- * it is not vmalloc()ated, try using the bio interface.
- *
- * If the buffer is big, if it is vmalloc()ated or if the underlying device
- * rejects the bio because it is too large, use dm-io layer to do the I/O.
- * dmio layer splits the I/O to multiple requests, solving the above
- * shortcomings.
- *--------------------------------------------------------------*/
-
-/*
- * dm-io completion routine. It just calls b->bio.bi_end_io, pretending
- * that the request was handled directly with bio interface.
- */
-static void dmio_complete(unsigned long error, void *context)
-{
- struct dm_buffer *b = context;
- int err = 0;
- if (error)
- err = -EIO;
- b->bio.bi_end_io(&b->bio, err);
-}
-
-static void use_dmio(struct dm_buffer *b, int rw, sector_t block, bio_end_io_t *end_io)
-{
- int r;
- struct dm_io_request io_req = {
- .bi_rw = rw,
- .notify.fn = dmio_complete,
- .notify.context = b,
- .client = b->c->dm_io,
- };
- struct dm_io_region region = {
- .bdev = b->c->bdev,
- .sector = block << b->c->sectors_per_block_bits,
- .count = b->c->block_size >> SECTOR_SHIFT,
- };
-
- if (b->data_mode != DATA_MODE_VMALLOC) {
- io_req.mem.type = DM_IO_KMEM;
- io_req.mem.ptr.addr = b->data;
- } else {
- io_req.mem.type = DM_IO_VMA;
- io_req.mem.ptr.vma = b->data;
- }
-
- b->bio.bi_end_io = end_io;
- r = dm_io(&io_req, 1, ®ion, NULL);
- if (r)
- end_io(&b->bio, r);
-}
-
-static void use_inline_bio(struct dm_buffer *b, int rw, sector_t block,
- bio_end_io_t *end_io)
-{
- char *ptr;
- int len;
-
- bio_init(&b->bio);
- b->bio.bi_io_vec = b->bio_vec;
- b->bio.bi_max_vecs = DM_BUFIO_INLINE_VECS;
- b->bio.bi_sector = block << b->c->sectors_per_block_bits;
- b->bio.bi_bdev = b->c->bdev;
- b->bio.bi_end_io = end_io;
-
- /*
- * we assume that if len >= PAGE_SIZE, ptr is page-aligned,
- * if len < PAGE_SIZE, the buffer doesn't cross page boundary.
- */
- ptr = b->data;
- len = b->c->block_size;
-
- if (len >= PAGE_SIZE)
- BUG_ON((unsigned long)ptr & (PAGE_SIZE - 1));
- else
- BUG_ON((unsigned long)ptr & (len - 1));
-
- do {
- if (!bio_add_page(&b->bio, virt_to_page(ptr),
- len < PAGE_SIZE ? len : PAGE_SIZE,
- virt_to_phys(ptr) & (PAGE_SIZE - 1))) {
- BUG_ON(b->c->block_size <= PAGE_SIZE);
- use_dmio(b, rw, block, end_io);
- }
-
- len -= PAGE_SIZE;
- ptr += PAGE_SIZE;
- } while (len > 0);
-
- submit_bio(rw, &b->bio);
-}
-
-static void submit_io(struct dm_buffer *b, int rw, sector_t block,
- bio_end_io_t *end_io)
-{
- if (b->c->block_size <= DM_BUFIO_INLINE_VECS * PAGE_SIZE &&
- b->data_mode != DATA_MODE_VMALLOC)
- use_inline_bio(b, rw, block, end_io);
- else
- use_dmio(b, rw, block, end_io);
-}
-
-/*----------------------------------------------------------------
- * Writing dirty buffers
- *--------------------------------------------------------------*/
-
-/*
- * The endio routine for write.
- *
- * Set the error, clear B_WRITING bit and wake anyone who was waiting on
- * it.
- */
-static void write_endio(struct bio *bio, int error)
-{
- struct dm_buffer *b = container_of(bio, struct dm_buffer, bio);
- b->write_error = error;
- if (error) {
- struct dm_bufio_client *c = b->c;
- (void)cmpxchg(&c->async_write_error, 0, error);
- }
- BUG_ON(!test_bit(B_WRITING, &b->state));
- smp_mb__before_clear_bit();
- clear_bit(B_WRITING, &b->state);
- smp_mb__after_clear_bit();
- wake_up_bit(&b->state, B_WRITING);
-}
-
-/*
- * This function is called when wait_on_bit is actually waiting.
- */
-static int do_io_schedule(void *word)
-{
- io_schedule();
- return 0;
-}
-
-/*
- * Initiate a write on a dirty buffer, but don't wait for it.
- *
- * - If the buffer is not dirty, exit.
- * - If there some previous write going on, wait for it to finish (we can't
- * have two writes on the same buffer simultaneously).
- * - Submit our write and don't wait on it. We set B_WRITING indicating
- * that there is a write in progress.
- */
-static void __write_dirty_buffer(struct dm_buffer *b)
-{
- if (!test_bit(B_DIRTY, &b->state))
- return;
- clear_bit(B_DIRTY, &b->state);
- wait_on_bit_lock(&b->state, B_WRITING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
- if (b->c->write_callback)
- b->c->write_callback(b);
- submit_io(b, WRITE, b->block, write_endio);
-}
-
-/*
- * Wait until any activity on the buffer finishes. Possibly write the
- * buffer if it is dirty. When this function finishes, there is no I/O
- * running on the buffer and the buffer is not dirty.
- */
-static void __make_buffer_clean(struct dm_buffer *b)
-{
- BUG_ON(b->hold_count);
- if (!b->state) /* fast case */
- return;
- wait_on_bit(&b->state, B_READING, do_io_schedule, TASK_UNINTERRUPTIBLE);
- __write_dirty_buffer(b);
- wait_on_bit(&b->state, B_WRITING, do_io_schedule, TASK_UNINTERRUPTIBLE);
-}
-
-/*
- * Find some buffer that is not held by anybody, clean it, unlink it and
- * return it. If "wait" is zero, try less hard and don't block.
- */
-static struct dm_buffer *__get_unclaimed_buffer(struct dm_bufio_client *c)
-{
- struct dm_buffer *b;
- list_for_each_entry_reverse(b, &c->lru[LIST_CLEAN], lru_list) {
- BUG_ON(test_bit(B_WRITING, &b->state));
- BUG_ON(test_bit(B_DIRTY, &b->state));
- if (!b->hold_count) {
- __make_buffer_clean(b);
- __unlink_buffer(b);
- return b;
- }
- }
-
- list_for_each_entry_reverse(b, &c->lru[LIST_DIRTY], lru_list) {
- BUG_ON(test_bit(B_READING, &b->state));
- if (!b->hold_count) {
- __make_buffer_clean(b);
- __unlink_buffer(b);
- return b;
- }
- }
- return NULL;
-}
-
-/*
- * Wait until some other threads free some buffer or release hold count on
- * some buffer.
- *
- * This function is entered with c->lock held, drops it and regains it
- * before exiting.
- */
-static void __wait_for_free_buffer(struct dm_bufio_client *c)
-{
- DECLARE_WAITQUEUE(wait, current);
-
- add_wait_queue(&c->free_buffer_wait, &wait);
- set_task_state(current, TASK_UNINTERRUPTIBLE);
- mutex_unlock(&c->lock);
-
- io_schedule();
-
- set_task_state(current, TASK_RUNNING);
- remove_wait_queue(&c->free_buffer_wait, &wait);
-
- mutex_lock(&c->lock);
-}
-
-/*
- * Allocate a new buffer. If the allocation is not possible, wait until
- * some other thread frees a buffer.
- *
- * May drop the lock and regain it.
- */
-static struct dm_buffer *__alloc_buffer_wait_no_callback(struct dm_bufio_client *c)
-{
- struct dm_buffer *b;
-
- while (1) {
- /*
- * This is useful for debugging. When we set cache size to 1,
- * no new buffers are allocated at all.
- */
- if (dm_bufio_cache_size_latch != 1) {
- /*
- * dm-bufio is resistant to allocation failures (it just keeps
- * one buffer reserved in cases all the allocations fail).
- * So set flags to not try too hard:
- * GFP_NOIO: don't recurse into the I/O layer
- * __GFP_NORETRY: don't retry and rather return failure
- * __GFP_NOMEMALLOC: don't use emergency reserves
- * __GFP_NOWARN: don't print a warning in case of failure
- */
- b = alloc_buffer(c, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
- if (b)
- return b;
- }
-
- if (!list_empty(&c->reserved_buffers)) {
- b = list_entry(c->reserved_buffers.next, struct dm_buffer,
- lru_list);
- list_del(&b->lru_list);
- c->need_reserved_buffers++;
- return b;
- }
-
- b = __get_unclaimed_buffer(c);
- if (b)
- return b;
-
- __wait_for_free_buffer(c);
- }
-}
-
-static struct dm_buffer *__alloc_buffer_wait(struct dm_bufio_client *c)
-{
- struct dm_buffer *b = __alloc_buffer_wait_no_callback(c);
- if (b && c->alloc_callback)
- c->alloc_callback(b);
- return b;
-}
-
-/*
- * Free a buffer and wake other threads waiting for free buffers.
- */
-static void __free_buffer_wake(struct dm_buffer *b)
-{
- struct dm_bufio_client *c = b->c;
-
- if (c->need_reserved_buffers) {
- list_add(&b->lru_list, &c->reserved_buffers);
- c->need_reserved_buffers--;
- } else
- free_buffer(b);
-
- wake_up(&c->free_buffer_wait);
-}
-
-static void __write_dirty_buffers_async(struct dm_bufio_client *c, int no_wait)
-{
- struct dm_buffer *b, *tmp;
- list_for_each_entry_safe_reverse(b, tmp, &c->lru[LIST_DIRTY], lru_list) {
- BUG_ON(test_bit(B_READING, &b->state));
- if (!test_bit(B_DIRTY, &b->state) &&
- !test_bit(B_WRITING, &b->state)) {
- __relink_lru(b, LIST_CLEAN);
- continue;
- }
- if (no_wait && test_bit(B_WRITING, &b->state))
- return;
- __write_dirty_buffer(b);
- }
-}
-
-/*
- * Get writeback threshold and buffer limit for a given client.
- */
-static void __get_memory_limit(struct dm_bufio_client *c,
- unsigned long *threshold_buffers,
- unsigned long *limit_buffers)
-{
- unsigned long buffers;
-
- if (dm_bufio_cache_size != dm_bufio_cache_size_latch) {
- mutex_lock(&dm_bufio_clients_lock);
- __cache_size_refresh();
- mutex_unlock(&dm_bufio_clients_lock);
- }
-
- buffers = dm_bufio_cache_size_per_client >>
- (c->sectors_per_block_bits + SECTOR_SHIFT);
- if (buffers < DM_BUFIO_MIN_BUFFERS)
- buffers = DM_BUFIO_MIN_BUFFERS;
- *limit_buffers = buffers;
- *threshold_buffers = buffers * DM_BUFIO_WRITEBACK_RATIO;
-}
-
-/*
- * Check if we're over watermark.
- * If we are over threshold_buffers, start freeing buffers.
- * If we're over "limit_buffers", block until we get under the limit.
- */
-static void __check_watermark(struct dm_bufio_client *c)
-{
- unsigned long threshold_buffers, limit_buffers;
- __get_memory_limit(c, &threshold_buffers, &limit_buffers);
-
- while (c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY] >
- limit_buffers) {
- struct dm_buffer *b;
- b = __get_unclaimed_buffer(c);
- if (!b)
- return;
- __free_buffer_wake(b);
- }
- if (c->n_buffers[LIST_DIRTY] > threshold_buffers)
- __write_dirty_buffers_async(c, 1);
-}
-
-/* Find a buffer in the hash. */
-static struct dm_buffer *__find(struct dm_bufio_client *c, sector_t block)
-{
- struct dm_buffer *b;
- struct hlist_node *hn;
- hlist_for_each_entry(b, hn, &c->cache_hash[DM_BUFIO_HASH(block)], hash_list) {
- if (b->block == block)
- return b;
- }
-
- return NULL;
-}
-
-/*----------------------------------------------------------------
- * Getting a buffer
- *--------------------------------------------------------------*/
-
-enum new_flag {
- NF_FRESH = 0,
- NF_READ = 1,
- NF_GET = 2
-};
-
-static struct dm_buffer *__bufio_new(struct dm_bufio_client *c, sector_t block, enum new_flag nf,
- struct dm_buffer **bp, int *need_submit)
-{
- struct dm_buffer *b, *new_b = NULL;
-
- *need_submit = 0;
- b = __find(c, block);
- if (b) {
- b->hold_count++;
- __relink_lru(b, test_bit(B_DIRTY, &b->state) ||
- test_bit(B_WRITING, &b->state));
- return b;
- }
-
- if (nf == NF_GET)
- return NULL;
-
- new_b = __alloc_buffer_wait(c);
-
- /*
- * We've had a period where the mutex was unlocked, so need to
- * recheck the hash table.
- */
- b = __find(c, block);
- if (b) {
- __free_buffer_wake(new_b);
- b->hold_count++;
- __relink_lru(b, test_bit(B_DIRTY, &b->state) ||
- test_bit(B_WRITING, &b->state));
- return b;
- }
-
- __check_watermark(c);
-
- b = new_b;
- b->hold_count = 1;
- b->read_error = 0;
- b->write_error = 0;
- __link_buffer(b, block, LIST_CLEAN);
-
- if (nf == NF_FRESH) {
- b->state = 0;
- return b;
- }
-
- b->state = 1 << B_READING;
- *need_submit = 1;
- return b;
-}
-
-/*
- * The endio routine for reading: set the error, clear the bit and wake up
- * anyone waiting on the buffer.
- */
-static void read_endio(struct bio *bio, int error)
-{
- struct dm_buffer *b = container_of(bio, struct dm_buffer, bio);
- b->read_error = error;
- BUG_ON(!test_bit(B_READING, &b->state));
- smp_mb__before_clear_bit();
- clear_bit(B_READING, &b->state);
- smp_mb__after_clear_bit();
- wake_up_bit(&b->state, B_READING);
-}
-
-/*
- * A common routine for dm_bufio_new and dm_bufio_read. Operation of these
- * function is very similar, except that dm_bufio_new doesn't read the
- * buffer from the disk (assuming that the caller overwrites all the data
- * and uses dm_bufio_mark_buffer_dirty to write new data back).
- */
-static void *new_read(struct dm_bufio_client *c, sector_t block, enum new_flag nf,
- struct dm_buffer **bp)
-{
- int need_submit;
- struct dm_buffer *b;
-
- mutex_lock(&c->lock);
- b = __bufio_new(c, block, nf, bp, &need_submit);
- mutex_unlock(&c->lock);
-
- if (!b || IS_ERR(b))
- return b;
- else {
- if (need_submit)
- submit_io(b, READ, b->block, read_endio);
-
- wait_on_bit(&b->state, B_READING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
- if (b->read_error != 0) {
- int error = b->read_error;
- dm_bufio_release(b);
- return ERR_PTR(error);
- }
- *bp = b;
- return b->data;
- }
-}
-
-void *dm_bufio_get(struct dm_bufio_client *c, sector_t block,
- struct dm_buffer **bp)
-{
- return new_read(c, block, NF_GET, bp);
-}
-
-void *dm_bufio_read(struct dm_bufio_client *c, sector_t block,
- struct dm_buffer **bp)
-{
- return new_read(c, block, NF_READ, bp);
-}
-
-void *dm_bufio_new(struct dm_bufio_client *c, sector_t block,
- struct dm_buffer **bp)
-{
- return new_read(c, block, NF_FRESH, bp);
-}
-
-void dm_bufio_release(struct dm_buffer *b)
-{
- struct dm_bufio_client *c = b->c;
- mutex_lock(&c->lock);
- BUG_ON(test_bit(B_READING, &b->state));
- BUG_ON(!b->hold_count);
- b->hold_count--;
- if (!b->hold_count) {
- wake_up(&c->free_buffer_wait);
-
- /*
- * If there were errors on the buffer, and the buffer is not
- * to be written, free the buffer. There is no point in caching
- * invalid buffer.
- */
- if ((b->read_error || b->write_error) &&
- !test_bit(B_WRITING, &b->state) &&
- !test_bit(B_DIRTY, &b->state)) {
- __unlink_buffer(b);
- __free_buffer_wake(b);
- }
- }
- mutex_unlock(&c->lock);
-}
-
-void dm_bufio_mark_buffer_dirty(struct dm_buffer *b)
-{
- struct dm_bufio_client *c = b->c;
-
- mutex_lock(&c->lock);
-
- if (!test_and_set_bit(B_DIRTY, &b->state))
- __relink_lru(b, LIST_DIRTY);
-
- mutex_unlock(&c->lock);
-}
-
-void dm_bufio_write_dirty_buffers_async(struct dm_bufio_client *c)
-{
- mutex_lock(&c->lock);
- __write_dirty_buffers_async(c, 0);
- mutex_unlock(&c->lock);
-}
-
-/*
- * For performance, it is essential that the buffers are written asynchronously
- * and simultaneously (so that the block layer can merge the writes) and then
- * waited upon.
- *
- * Finally, we flush hardware disk cache.
- */
-int dm_bufio_write_dirty_buffers(struct dm_bufio_client *c)
-{
- int a, f;
- unsigned long buffers_processed = 0;
- struct dm_buffer *b, *tmp;
-
- mutex_lock(&c->lock);
- __write_dirty_buffers_async(c, 0);
-
-again:
- list_for_each_entry_safe_reverse(b, tmp, &c->lru[LIST_DIRTY], lru_list) {
- int dropped_lock = 0;
- if (buffers_processed < c->n_buffers[LIST_DIRTY])
- buffers_processed++;
-
- BUG_ON(test_bit(B_READING, &b->state));
- if (test_bit(B_WRITING, &b->state)) {
- if (buffers_processed < c->n_buffers[LIST_DIRTY]) {
- dropped_lock = 1;
- b->hold_count++;
- mutex_unlock(&c->lock);
- wait_on_bit(&b->state, B_WRITING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
- mutex_lock(&c->lock);
- b->hold_count--;
- } else
- wait_on_bit(&b->state, B_WRITING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
- }
- if (!test_bit(B_DIRTY, &b->state) &&
- !test_bit(B_WRITING, &b->state))
- __relink_lru(b, LIST_CLEAN);
-
- /*
- * If we dropped the lock, the list is no longer consistent,
- * so we must restart the search.
- *
- * In the most common case, the buffer just processed is
- * relinked to the clean list, so we won't loop scanning the
- * same buffer again and again.
- *
- * This may livelock if there is another thread simultaneously
- * dirtying buffers, so we count the number of buffers walked
- * and if it exceeds the total number of buffers, it means that
- * someone is doing some writes simultaneously with us --- in
- * this case, stop dropping the lock.
- */
- if (dropped_lock)
- goto again;
- }
- wake_up(&c->free_buffer_wait);
- mutex_unlock(&c->lock);
-
- a = xchg(&c->async_write_error, 0);
- f = dm_bufio_issue_flush(c);
- if (a)
- return a;
- return f;
-}
-
-/*
- * Use dm-io to send and empty barrier flush the device.
- */
-int dm_bufio_issue_flush(struct dm_bufio_client *c)
-{
- struct dm_io_request io_req = {
- .bi_rw = REQ_FLUSH,
- .mem.type = DM_IO_KMEM,
- .mem.ptr.addr = NULL,
- .client = c->dm_io,
- };
- struct dm_io_region io_reg = {
- .bdev = c->bdev,
- .sector = 0,
- .count = 0,
- };
- return dm_io(&io_req, 1, &io_reg, NULL);
-}
-
-/*
- * We first delete any other buffer that may be at that new location.
- *
- * Then, we write the buffer to the original location if it was dirty.
- *
- * Then, if we are the only one who is holding the buffer, relink the buffer
- * in the hash queue for the new location.
- *
- * If there was someone else holding the buffer, we write it to the new
- * location but not relink it, because that other user needs to have the buffer
- * at the same place.
- */
-void dm_bufio_release_move(struct dm_buffer *b, sector_t new_block)
-{
- struct dm_bufio_client *c = b->c;
- struct dm_buffer *new;
-
- mutex_lock(&c->lock);
-
-retry:
- new = __find(c, new_block);
- if (new) {
- if (new->hold_count) {
- __wait_for_free_buffer(c);
- goto retry;
- }
-
- __make_buffer_clean(new); /* FIXME: is there any point waiting for a write that's going to be overwritten in a bit? */
- __unlink_buffer(new);
- __free_buffer_wake(new);
- }
-
- BUG_ON(!b->hold_count);
- BUG_ON(test_bit(B_READING, &b->state));
- __write_dirty_buffer(b);
- if (b->hold_count == 1) {
- wait_on_bit(&b->state, B_WRITING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
- set_bit(B_DIRTY, &b->state);
- __unlink_buffer(b);
- __link_buffer(b, new_block, LIST_DIRTY);
- } else {
- wait_on_bit_lock(&b->state, B_WRITING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
- submit_io(b, WRITE, new_block, write_endio);
- wait_on_bit(&b->state, B_WRITING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
- }
- mutex_unlock(&c->lock);
- dm_bufio_release(b);
-}
-
-unsigned dm_bufio_get_block_size(struct dm_bufio_client *c)
-{
- return c->block_size;
-}
-
-sector_t dm_bufio_get_device_size(struct dm_bufio_client *c)
-{
- return i_size_read(c->bdev->bd_inode) >>
- (SECTOR_SHIFT + c->sectors_per_block_bits);
-}
-
-sector_t dm_bufio_get_block_number(struct dm_buffer *b)
-{
- return b->block;
-}
-
-void *dm_bufio_get_block_data(struct dm_buffer *b)
-{
- return b->data;
-}
-
-void *dm_bufio_get_aux_data(struct dm_buffer *b)
-{
- return b + 1;
-}
-
-struct dm_bufio_client *dm_bufio_get_client(struct dm_buffer *b)
-{
- return b->c;
-}
-
-static void drop_buffers(struct dm_bufio_client *c)
-{
- struct dm_buffer *b;
- int i;
-
- /* an optimization ... so that the buffers are not written one-by-one */
- dm_bufio_write_dirty_buffers_async(c);
-
- mutex_lock(&c->lock);
- while ((b = __get_unclaimed_buffer(c)))
- __free_buffer_wake(b);
-
- for (i = 0; i < LIST_N; i++) {
- list_for_each_entry(b, &c->lru[i], lru_list) {
- printk(KERN_ERR "dm-bufio: leaked buffer %llx, hold count %u, list %d",
- (unsigned long long)b->block, b->hold_count, i);
- }
- }
- for (i = 0; i < LIST_N; i++)
- BUG_ON(!list_empty(&c->lru[i]));
-
- mutex_unlock(&c->lock);
-}
-
-/*
- * Test if the buffer is unused and too old, and commit it.
- * At if noio is set, we must not do any I/O because we hold
- * dm_bufio_clients_lock and we would risk deadlock if the I/O gets rerouted to
- * different bufio client.
- */
-static int __cleanup_old_buffer(struct dm_buffer *b, gfp_t gfp,
- unsigned long max_age)
-{
- if (jiffies - b->last_accessed < max_age)
- return 1;
-
- if (!(gfp & __GFP_IO)) {
- if (test_bit(B_READING, &b->state) ||
- test_bit(B_WRITING, &b->state) ||
- test_bit(B_DIRTY, &b->state))
- return 1;
- }
-
- if (b->hold_count != 0)
- return 1;
-
- __make_buffer_clean(b);
- __unlink_buffer(b);
- __free_buffer_wake(b);
-
- return 0;
-}
-
-static void __scan(struct dm_bufio_client *c, unsigned long nr_to_scan,
- struct shrink_control *sc)
-{
- int l;
- struct dm_buffer *b, *tmp;
-
- for (l = 0; l < LIST_N; l++) {
- list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list) {
- if (!__cleanup_old_buffer(b, sc->gfp_mask, 0)) {
- if (!--nr_to_scan)
- return;
- }
- }
- }
-}
-
-static int shrink(struct shrinker *shrinker, struct shrink_control *sc)
-{
- struct dm_bufio_client *c =
- container_of(shrinker, struct dm_bufio_client, shrinker);
- unsigned long r;
- unsigned long nr_to_scan = sc->nr_to_scan;
-
- if (sc->gfp_mask & __GFP_IO) {
- mutex_lock(&c->lock);
- } else {
- if (!mutex_trylock(&c->lock))
- return !nr_to_scan ? 0 : -1;
- }
-
- if (nr_to_scan)
- __scan(c, nr_to_scan, sc);
-
- r = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];
- if (r > INT_MAX)
- r = INT_MAX;
-
- mutex_unlock(&c->lock);
-
- return r;
-}
-
-/* Create the buffering interface */
-struct dm_bufio_client *
-dm_bufio_client_create(struct block_device *bdev, unsigned block_size,
- unsigned reserved_buffers, unsigned aux_size,
- void (*alloc_callback)(struct dm_buffer *),
- void (*write_callback)(struct dm_buffer *))
-{
- int r;
- struct dm_bufio_client *c;
- unsigned i;
-
- BUG_ON(block_size < 1 << SECTOR_SHIFT ||
- (block_size & (block_size - 1)));
-
- c = kmalloc(sizeof(*c), GFP_KERNEL);
- if (!c) {
- r = -ENOMEM;
- goto bad_client;
- }
- c->cache_hash = vmalloc(sizeof(struct hlist_head) << DM_BUFIO_HASH_BITS);
- if (!c->cache_hash) {
- r = -ENOMEM;
- goto bad_hash;
- }
-
- c->bdev = bdev;
- c->block_size = block_size;
- c->sectors_per_block_bits = ffs(block_size) - 1 - SECTOR_SHIFT;
- c->pages_per_block_bits = (ffs(block_size) - 1 >= PAGE_SHIFT) ?
- ffs(block_size) - 1 - PAGE_SHIFT : 0;
- c->blocks_per_page_bits = (ffs(block_size) - 1 < PAGE_SHIFT ?
- PAGE_SHIFT - (ffs(block_size) - 1) : 0);
-
- c->aux_size = aux_size;
- c->alloc_callback = alloc_callback;
- c->write_callback = write_callback;
- for (i = 0; i < LIST_N; i++) {
- INIT_LIST_HEAD(&c->lru[i]);
- c->n_buffers[i] = 0;
- }
- for (i = 0; i < 1 << DM_BUFIO_HASH_BITS; i++)
- INIT_HLIST_HEAD(&c->cache_hash[i]);
- mutex_init(&c->lock);
- INIT_LIST_HEAD(&c->reserved_buffers);
- c->need_reserved_buffers = reserved_buffers;
-
- init_waitqueue_head(&c->free_buffer_wait);
- c->async_write_error = 0;
-
- c->dm_io = dm_io_client_create();
- if (IS_ERR(c->dm_io)) {
- r = PTR_ERR(c->dm_io);
- goto bad_dm_io;
- }
-
- mutex_lock(&dm_bufio_clients_lock);
- if (c->blocks_per_page_bits) {
- if (!DM_BUFIO_CACHE_NAME(c)) {
- DM_BUFIO_CACHE_NAME(c) = kasprintf(GFP_KERNEL,
- "dm_bufio_cache-%u", c->block_size);
- if (!DM_BUFIO_CACHE_NAME(c)) {
- r = -ENOMEM;
- mutex_unlock(&dm_bufio_clients_lock);
- goto bad_cache;
- }
- }
- if (!DM_BUFIO_CACHE(c)) {
- DM_BUFIO_CACHE(c) = kmem_cache_create(
- DM_BUFIO_CACHE_NAME(c),
- c->block_size,
- c->block_size, 0, NULL);
- if (!DM_BUFIO_CACHE(c)) {
- r = -ENOMEM;
- mutex_unlock(&dm_bufio_clients_lock);
- goto bad_cache;
- }
- }
- }
- mutex_unlock(&dm_bufio_clients_lock);
-
- while (c->need_reserved_buffers) {
- struct dm_buffer *b = alloc_buffer(c, GFP_KERNEL);
- if (!b) {
- r = -ENOMEM;
- goto bad_buffer;
- }
- __free_buffer_wake(b);
- }
-
- mutex_lock(&dm_bufio_clients_lock);
- dm_bufio_client_count++;
- list_add(&c->client_list, &dm_bufio_all_clients);
- __cache_size_refresh();
- mutex_unlock(&dm_bufio_clients_lock);
-
- c->shrinker.shrink = shrink;
- c->shrinker.seeks = 1;
- c->shrinker.batch = 0;
- register_shrinker(&c->shrinker);
-
- return c;
-
-bad_buffer:
-bad_cache:
- while (!list_empty(&c->reserved_buffers)) {
- struct dm_buffer *b = list_entry(c->reserved_buffers.next,
- struct dm_buffer, lru_list);
- list_del(&b->lru_list);
- free_buffer(b);
- }
- dm_io_client_destroy(c->dm_io);
-bad_dm_io:
- vfree(c->cache_hash);
-bad_hash:
- kfree(c);
-bad_client:
- return ERR_PTR(r);
-}
-
-/*
- * Free the buffering interface.
- * It is required that there are no references on any buffers.
- */
-void dm_bufio_client_destroy(struct dm_bufio_client *c)
-{
- unsigned i;
- drop_buffers(c);
-
- unregister_shrinker(&c->shrinker);
- mutex_lock(&dm_bufio_clients_lock);
- list_del(&c->client_list);
- dm_bufio_client_count--;
- __cache_size_refresh();
- mutex_unlock(&dm_bufio_clients_lock);
-
- for (i = 0; i < 1 << DM_BUFIO_HASH_BITS; i++)
- BUG_ON(!hlist_empty(&c->cache_hash[i]));
- BUG_ON(c->need_reserved_buffers);
- while (!list_empty(&c->reserved_buffers)) {
- struct dm_buffer *b = list_entry(c->reserved_buffers.next,
- struct dm_buffer, lru_list);
- list_del(&b->lru_list);
- free_buffer(b);
- }
-
- for (i = 0; i < LIST_N; i++) {
- if (c->n_buffers[i] != 0) {
- printk(KERN_ERR "dm-bufio: leaked buffer count %d: %ld",
- i, c->n_buffers[i]);
- }
- }
- for (i = 0; i < LIST_N; i++)
- BUG_ON(c->n_buffers[i] != 0);
-
- dm_io_client_destroy(c->dm_io);
- vfree(c->cache_hash);
- kfree(c);
-}
-
-static void cleanup_old_buffers(void)
-{
- unsigned long long max_age;
- struct dm_bufio_client *c;
-
- max_age = dm_bufio_max_age;
- barrier(); /* prevent reusing of dm_bufio_max_age */
- max_age *= HZ;
- if (max_age > ULONG_MAX)
- max_age = ULONG_MAX;
-
- mutex_lock(&dm_bufio_clients_lock);
- list_for_each_entry(c, &dm_bufio_all_clients, client_list) {
- if (!mutex_trylock(&c->lock))
- continue;
-
- while (!list_empty(&c->lru[LIST_CLEAN])) {
- struct dm_buffer *b;
- b = list_entry(c->lru[LIST_CLEAN].prev,
- struct dm_buffer, lru_list);
- if (__cleanup_old_buffer(b, 0, max_age))
- break;
- }
-
- mutex_unlock(&c->lock);
- }
- mutex_unlock(&dm_bufio_clients_lock);
-}
-
-
-static struct workqueue_struct *dm_bufio_wq;
-static struct delayed_work dm_bufio_work;
-
-static void work_fn(struct work_struct *w)
-{
- cleanup_old_buffers();
- queue_delayed_work(dm_bufio_wq, &dm_bufio_work, DM_BUFIO_WORK_TIMER * HZ);
-}
-
-/*----------------------------------------------------------------
- * Module setup
- *--------------------------------------------------------------*/
-
-/*
- * This is called only once for the whole dm_bufio module.
- * It initializes memory limit.
- */
-static int __init dm_bufio_init(void)
-{
- __u64 mem;
-
- memset(&dm_bufio_caches, 0, sizeof dm_bufio_caches);
- memset(&dm_bufio_cache_names, 0, sizeof dm_bufio_cache_names);
-
- mem = (__u64)((totalram_pages - totalhigh_pages) * DM_BUFIO_MEMORY_RATIO)
- << PAGE_SHIFT;
- if (mem > ULONG_MAX)
- mem = ULONG_MAX;
-#ifdef CONFIG_MMU
- /*
- * Get the size of vmalloc space,
- * the same way as VMALLOC_TOTAL in fs/proc/internal.h
- */
- if (mem > (VMALLOC_END - VMALLOC_START) * DM_BUFIO_VMALLOC_RATIO)
- mem = (VMALLOC_END - VMALLOC_START) * DM_BUFIO_VMALLOC_RATIO;
-#endif
- dm_bufio_default_cache_size = mem;
- mutex_lock(&dm_bufio_clients_lock);
- __cache_size_refresh();
- mutex_unlock(&dm_bufio_clients_lock);
-
- dm_bufio_wq = create_singlethread_workqueue("dm_bufio_cache");
- if (!dm_bufio_wq)
- return -ENOMEM;
- INIT_DELAYED_WORK(&dm_bufio_work, work_fn);
- queue_delayed_work(dm_bufio_wq, &dm_bufio_work, DM_BUFIO_WORK_TIMER * HZ);
-
- return 0;
-}
-
-/*
- * This is called once when unloading the dm_bufio module.
- */
-static void __exit dm_bufio_exit(void)
-{
- int bug = 0;
- int i;
-
- cancel_delayed_work_sync(&dm_bufio_work);
- destroy_workqueue(dm_bufio_wq);
-
- for (i = 0; i < ARRAY_SIZE(dm_bufio_caches); i++) {
- struct kmem_cache *kc = dm_bufio_caches[i];
- if (kc)
- kmem_cache_destroy(kc);
- }
-
- for (i = 0; i < ARRAY_SIZE(dm_bufio_cache_names); i++)
- kfree(dm_bufio_cache_names[i]);
-
- if (dm_bufio_client_count != 0) {
- printk(KERN_CRIT "%s: dm_bufio_client_count leaked: %d",
- __func__, dm_bufio_client_count);
- bug = 1;
- }
-
- if (dm_bufio_current_allocated != 0) {
- printk(KERN_CRIT "%s: dm_bufio_current_allocated leaked: %lu",
- __func__, dm_bufio_current_allocated);
- bug = 1;
- }
-
- if (dm_bufio_allocated_get_free_pages != 0) {
- printk(KERN_CRIT "%s: dm_bufio_allocated_get_free_pages leaked: %lu",
- __func__, dm_bufio_allocated_get_free_pages);
- bug = 1;
- }
-
- if (dm_bufio_allocated_vmalloc != 0) {
- printk(KERN_CRIT "%s: dm_bufio_vmalloc leaked: %lu",
- __func__, dm_bufio_allocated_vmalloc);
- bug = 1;
- }
-
- if (bug)
- BUG();
-}
-
-module_init(dm_bufio_init)
-module_exit(dm_bufio_exit)
-
-module_param_named(max_cache_size_bytes, dm_bufio_cache_size, ulong, 0644);
-MODULE_PARM_DESC(max_cache_size_bytes, "Size of metadata cache");
-
-module_param_named(max_age_seconds, dm_bufio_max_age, uint, 0644);
-MODULE_PARM_DESC(max_age_seconds, "Max age of a buffer in seconds");
-
-module_param_named(peak_allocated_bytes, dm_bufio_peak_allocated, ulong, 0644);
-MODULE_PARM_DESC(peak_allocated_bytes, "Tracks the maximum allocated memory");
-
-module_param_named(allocated_kmem_cache_bytes, dm_bufio_allocated_kmem_cache, ulong, 0444);
-MODULE_PARM_DESC(allocated_kmem_cache_bytes, "Memory allocated with kmem_cache_alloc");
-
-module_param_named(allocated_get_free_pages_bytes, dm_bufio_allocated_get_free_pages, ulong, 0444);
-MODULE_PARM_DESC(allocated_get_free_pages_bytes, "Memory allocated with get_free_pages");
-
-module_param_named(allocated_vmalloc_bytes, dm_bufio_allocated_vmalloc, ulong, 0444);
-MODULE_PARM_DESC(allocated_vmalloc_bytes, "Memory allocated with vmalloc");
-
-module_param_named(current_allocated_bytes, dm_bufio_current_allocated, ulong, 0444);
-MODULE_PARM_DESC(current_allocated_bytes, "Memory currently used by the cache");
-
-MODULE_AUTHOR("Mikulas Patocka <dm-devel@redhat.com>");
-MODULE_DESCRIPTION(DM_NAME " buffered I/O library");
-MODULE_LICENSE("GPL");
Index: linux-3.1-rc9/drivers/md/persistent-data/dm-bufio.h
===================================================================
--- linux-3.1-rc9.orig/drivers/md/persistent-data/dm-bufio.h
+++ /dev/null
@@ -1,110 +0,0 @@
-/*
- * Copyright (C) 2009-2011 2011 Red Hat, Inc.
- *
- * This file is released under the GPL.
- */
-
-#ifndef DM_BUFIO_H
-#define DM_BUFIO_H
-
-#include <linux/blkdev.h>
-#include <linux/types.h>
-
-/*----------------------------------------------------------------*/
-
-struct dm_bufio_client;
-struct dm_buffer;
-
-/*
- * Create a buffered IO cache on a given device
- */
-struct dm_bufio_client *
-dm_bufio_client_create(struct block_device *bdev, unsigned block_size,
- unsigned reserved_buffers, unsigned aux_size,
- void (*alloc_callback)(struct dm_buffer *),
- void (*write_callback)(struct dm_buffer *));
-
-/*
- * Release a buffered IO cache.
- */
-void dm_bufio_client_destroy(struct dm_bufio_client *c);
-
-/*
- * WARNING: to avoid deadlocks, these conditions are observed:
- *
- * - At most one thread can hold at most "reserved_buffers" simultaneously.
- * - Each other threads can hold at most one buffer.
- * - Threads which call only dm_bufio_get can hold unlimited number of
- * buffers.
- */
-
-/*
- * Read a given block from disk. Returns pointer to data. Returns a
- * pointer to dm_buffer that can be used to release the buffer or to make
- * it dirty.
- */
-void *dm_bufio_read(struct dm_bufio_client *c, sector_t block,
- struct dm_buffer **bp);
-
-/*
- * Like dm_bufio_read, but return buffer from cache, don't read
- * it. If the buffer is not in the cache, return NULL.
- */
-void *dm_bufio_get(struct dm_bufio_client *c, sector_t block,
- struct dm_buffer **bp);
-
-/*
- * Like dm_bufio_read, but don't read anything from the disk. It is
- * expected that the caller initializes the buffer and marks it dirty.
- */
-void *dm_bufio_new(struct dm_bufio_client *c, sector_t block,
- struct dm_buffer **bp);
-
-/*
- * Release a reference obtained with dm_bufio_{read,get,new}. The data
- * pointer and dm_buffer pointer is no longer valid after this call.
- */
-void dm_bufio_release(struct dm_buffer *b);
-
-/*
- * Mark a buffer dirty. It should be called after the buffer is modified.
- *
- * In case of memory pressure, the buffer may be written after
- * dm_bufio_mark_buffer_dirty, but before dm_bufio_write_dirty_buffers. So
- * dm_bufio_write_dirty_buffers guarantees that the buffer is on-disk but
- * the actual writing may occur earlier.
- */
-void dm_bufio_mark_buffer_dirty(struct dm_buffer *b);
-
-/*
- * Initiate writing of dirty buffers, without waiting for completion.
- */
-void dm_bufio_write_dirty_buffers_async(struct dm_bufio_client *c);
-
-/*
- * Write all dirty buffers. Guarantees that all dirty buffers created prior
- * to this call are on disk when this call exits.
- */
-int dm_bufio_write_dirty_buffers(struct dm_bufio_client *c);
-
-/*
- * Send an empty write barrier to the device to flush hardware disk cache.
- */
-int dm_bufio_issue_flush(struct dm_bufio_client *c);
-
-/*
- * Like dm_bufio_release but also move the buffer to the new
- * block. dm_bufio_write_dirty_buffers is needed to commit the new block.
- */
-void dm_bufio_release_move(struct dm_buffer *b, sector_t new_block);
-
-unsigned dm_bufio_get_block_size(struct dm_bufio_client *c);
-sector_t dm_bufio_get_device_size(struct dm_bufio_client *c);
-sector_t dm_bufio_get_block_number(struct dm_buffer *b);
-void *dm_bufio_get_block_data(struct dm_buffer *b);
-void *dm_bufio_get_aux_data(struct dm_buffer *b);
-struct dm_bufio_client *dm_bufio_get_client(struct dm_buffer *b);
-
-/*----------------------------------------------------------------*/
-
-#endif