#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/bio.h>
#include <linux/mm.h>
#include <linux/gfp.h>
#include <linux/pagemap.h>
#include <linux/page-flags.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h>
#include <linux/swap.h>
#include <linux/version.h>
#include <linux/writeback.h>
#include <linux/pagevec.h>
#include "extent_io.h"
#include "extent_map.h"
/* temporary define until extent_map moves out of btrfs */
struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
unsigned long extra_flags,
void (*ctor)(void *, struct kmem_cache *,
unsigned long));
static struct kmem_cache *extent_state_cache;
static struct kmem_cache *extent_buffer_cache;
static LIST_HEAD(buffers);
static LIST_HEAD(states);
static spinlock_t leak_lock = SPIN_LOCK_UNLOCKED;
#define BUFFER_LRU_MAX 64
struct tree_entry {
u64 start;
u64 end;
struct rb_node rb_node;
};
struct extent_page_data {
struct bio *bio;
struct extent_io_tree *tree;
get_extent_t *get_extent;
};
int __init extent_io_init(void)
{
extent_state_cache = btrfs_cache_create("extent_state",
sizeof(struct extent_state), 0,
NULL);
if (!extent_state_cache)
return -ENOMEM;
extent_buffer_cache = btrfs_cache_create("extent_buffers",
sizeof(struct extent_buffer), 0,
NULL);
if (!extent_buffer_cache)
goto free_state_cache;
return 0;
free_state_cache:
kmem_cache_destroy(extent_state_cache);
return -ENOMEM;
}
void extent_io_exit(void)
{
struct extent_state *state;
struct extent_buffer *eb;
while (!list_empty(&states)) {
state = list_entry(states.next, struct extent_state, leak_list);
printk("state leak: start %Lu end %Lu state %lu in tree %p refs %d\n", state->start, state->end, state->state, state->tree, atomic_read(&state->refs));
list_del(&state->leak_list);
kmem_cache_free(extent_state_cache, state);
}
while (!list_empty(&buffers)) {
eb = list_entry(buffers.next, struct extent_buffer, leak_list);
printk("buffer leak start %Lu len %lu refs %d\n", eb->start, eb->len, atomic_read(&eb->refs));
list_del(&eb->leak_list);
kmem_cache_free(extent_buffer_cache, eb);
}
if (extent_state_cache)
kmem_cache_destroy(extent_state_cache);
if (extent_buffer_cache)
kmem_cache_destroy(extent_buffer_cache);
}
void extent_io_tree_init(struct extent_io_tree *tree,
struct address_space *mapping, gfp_t mask)
{
tree->state.rb_node = NULL;
tree->ops = NULL;
tree->dirty_bytes = 0;
spin_lock_init(&tree->lock);
spin_lock_init(&tree->lru_lock);
tree->mapping = mapping;
INIT_LIST_HEAD(&tree->buffer_lru);
tree->lru_size = 0;
tree->last = NULL;
}
EXPORT_SYMBOL(extent_io_tree_init);
void extent_io_tree_empty_lru(struct extent_io_tree *tree)
{
struct extent_buffer *eb;
while(!list_empty(&tree->buffer_lru)) {
eb = list_entry(tree->buffer_lru.next, struct extent_buffer,
lru);
list_del_init(&eb->lru);
free_extent_buffer(eb);
}
}
EXPORT_SYMBOL(extent_io_tree_empty_lru);
struct extent_state *alloc_extent_state(gfp_t mask)
{
struct extent_state *state;
unsigned long flags;
state = kmem_cache_alloc(extent_state_cache, mask);
if (!state)
return state;
state->state = 0;
state->private = 0;
state->tree = NULL;
spin_lock_irqsave(&leak_lock, flags);
list_add(&state->leak_list, &states);
spin_unlock_irqrestore(&leak_lock, flags);
atomic_set(&state->refs, 1);
init_waitqueue_head(&state->wq);
return state;
}
EXPORT_SYMBOL(alloc_extent_state);
void free_extent_state(struct extent_state *state)
{
if (!state)
return;
if (atomic_dec_and_test(&state->refs)) {
unsigned long flags;
WARN_ON(state->tree);
spin_lock_irqsave(&leak_lock, flags);
list_del(&state->leak_list);
spin_unlock_irqrestore(&leak_lock, flags);
kmem_cache_free(extent_state_cache, state);
}
}
EXPORT_SYMBOL(free_extent_state);
static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
struct rb_node *node)
{
struct rb_node ** p = &root->rb_node;
struct rb_node * parent = NULL;
struct tree_entry *entry;
while(*p) {
parent = *p;
entry = rb_entry(parent, struct tree_entry, rb_node);
if (offset < entry->start)
p = &(*p)->rb_left;
else if (offset > entry->end)
p = &(*p)->rb_right;
else
return parent;
}
entry = rb_entry(node, struct tree_entry, rb_node);
rb_link_node(node, parent, p);
rb_insert_color(node, root);
return NULL;
}
static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
struct rb_node **prev_ret,
struct rb_node **next_ret)
{
struct rb_root *root = &tree->state;
struct rb_node * n = root->rb_node;
struct rb_node *prev = NULL;
struct rb_node *orig_prev = NULL;
struct tree_entry *entry;
struct tree_entry *prev_entry = NULL;
if (tree->last) {
struct extent_state *state;
state = tree->last;
if (state->start <= offset && offset <= state->end)
return &tree->last->rb_node;
}
while(n) {
entry = rb_entry(n, struct tree_entry, rb_node);
prev = n;
prev_entry = entry;
if (offset < entry->start)
n = n->rb_left;
else if (offset > entry->end)
n = n->rb_right;
else {
tree->last = rb_entry(n, struct extent_state, rb_node);
return n;
}
}
if (prev_ret) {
orig_prev = prev;
while(prev && offset > prev_entry->end) {
prev = rb_next(prev);
prev_entry = rb_entry(prev, struct tree_entry, rb_node);
}
*prev_ret = prev;
prev = orig_prev;
}
if (next_ret) {
prev_entry = rb_entry(prev, struct tree_entry, rb_node);
while(prev && offset < prev_entry->start) {
prev = rb_prev(prev);
prev_entry = rb_entry(prev, struct tree_entry, rb_node);
}
*next_ret = prev;
}
return NULL;
}
static inline struct rb_node *tree_search(struct extent_io_tree *tree,
u64 offset)
{
struct rb_node *prev = NULL;
struct rb_node *ret;
ret = __etree_search(tree, offset, &prev, NULL);
if (!ret) {
if (prev) {
tree->last = rb_entry(prev, struct extent_state,
rb_node);
}
return prev;
}
return ret;
}
/*
* utility function to look for merge candidates inside a given range.
* Any extents with matching state are merged together into a single
* extent in the tree. Extents with EXTENT_IO in their state field
* are not merged because the end_io handlers need to be able to do
* operations on them without sleeping (or doing allocations/splits).
*
* This should be called with the tree lock held.
*/
static int merge_state(struct extent_io_tree *tree,
struct extent_state *state)
{
struct extent_state *other;
struct rb_node *other_node;
if (state->state & EXTENT_IOBITS)
return 0;
other_node = rb_prev(&state->rb_node);
if (other_node) {
other = rb_entry(other_node, struct extent_state, rb_node);
if (other->end == state->start - 1 &&
other->state == state->state) {
state->start = other->start;
other->tree = NULL;
if (tree->last == other)
tree->last = state;
rb_erase(&other->rb_node, &tree->state);
free_extent_state(other);
}
}
other_node = rb_next(&state->rb_node);
if (other_node) {
other = rb_entry(other_node, struct extent_state, rb_node);
if (other->start == state->end + 1 &&
other->state == state->state) {
other->start = state->start;
state->tree = NULL;
if (tree->last == state)
tree->last = other;
rb_erase(&state->rb_node, &tree->state);
free_extent_state(state);
}
}
return 0;
}
static void set_state_cb(struct extent_io_tree *tree,
struct extent_state *state,
unsigned long bits)
{
if (tree->ops && tree->ops->set_bit_hook) {
tree->ops->set_bit_hook(tree->mapping->host, state->start,
state->end, state->state, bits);
}
}
static void clear_state_cb(struct extent_io_tree *tree,
struct extent_state *state,
unsigned long bits)
{
if (tree->ops && tree->ops->set_bit_hook) {
tree->ops->clear_bit_hook(tree->mapping->host, state->start,
state->end, state->state, bits);
}
}
/*
* insert an extent_state struct into the tree. 'bits' are set on the
* struct before it is inserted.
*
* This may return -EEXIST if the extent is already there, in which case the
* state struct is freed.
*
* The tree lock is not taken internally. This is a utility function and
* probably isn't what you want to call (see set/clear_extent_bit).
*/
static int insert_state(struct extent_io_tree *tree,
struct extent_state *state, u64 start, u64 end,
int bits)
{
struct rb_node *node;
if (end < start) {
printk("end < start %Lu %Lu\n", end, start);
WARN_ON(1);
}
if (bits & EXTENT_DIRTY)
tree->dirty_bytes += end - start + 1;
set_state_cb(tree, state, bits);
state->state |= bits;
state->start = start;
state->end = end;
node = tree_insert(&tree->state, end, &state->rb_node);
if (node) {
struct extent_state *found;
found = rb_entry(node, struct extent_state, rb_node);
printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, start, end);
free_extent_state(state);
return -EEXIST;
}
state->tree = tree;
tree->last = state;
merge_state(tree, state);
return 0;
}
/*
* split a given extent state struct in two, inserting the preallocated
* struct 'prealloc' as the newly created second half. 'split' indicates an
* offset inside 'orig' where it should be split.
*
* Before calling,
* the tree has 'orig' at [orig->start, orig->end]. After calling, there
* are two extent state structs in the tree:
* prealloc: [orig->start, split - 1]
* orig: [ split, orig->end ]
*
* The tree locks are not taken by this function. They need to be held
* by the caller.
*/
static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
struct extent_state *prealloc, u64 split)
{
struct rb_node *node;
prealloc->start = orig->start;
prealloc->end = split - 1;
prealloc->state = orig->state;
orig->start = split;
node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
if (node) {
struct extent_state *found;
found = rb_entry(node, struct extent_state, rb_node);
printk("found node %Lu %Lu on insert of %Lu %Lu\n", found->start, found->end, prealloc->start, prealloc->end);
free_extent_state(prealloc);
return -EEXIST;
}
prealloc->tree = tree;
return 0;
}
/*
* utility function to clear some bits in an extent state struct.
* it will optionally wake up any one waiting on this state (wake == 1), or
* forcibly remove the state from the tree (delete == 1).
*
* If no bits are set on the state struct after clearing things, the
* struct is freed and removed from the tree
*/
static int clear_state_bit(struct extent_io_tree *tree,
struct extent_state *state, int bits, int wake,
int delete)
{
int ret = state->state & bits;
if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
u64 range = state->end - state->start + 1;
WARN_ON(range > tree->dirty_bytes);
tree->dirty_bytes -= range;
}
clear_state_cb(tree, state, bits);
state->state &= ~bits;
if (wake)
wake_up(&state->wq);
if (delete || state->state == 0) {
if (state->tree) {
clear_state_cb(tree, state, state->state);
if (tree->last == state) {
tree->last = extent_state_next(state);
}
rb_erase(&state->rb_node, &tree->state);
state->tree = NULL;
free_extent_state(state);
} else {
WARN_ON(1);
}
} else {
merge_state(tree, state);
}
return ret;
}
/*
* clear some bits on a range in the tree. This may require splitting
* or inserting elements in the tree, so the gfp mask is used to
* indicate which allocations or sleeping are allowed.
*
* pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove
* the given range from the tree regardless of state (ie for truncate).
*
* the range [start, end] is inclusive.
*
* This takes the tree lock, and returns < 0 on error, > 0 if any of the
* bits were already set, or zero if none of the bits were already set.
*/
int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
int bits, int wake, int delete, gfp_t mask)
{
struct extent_state *state;
struct extent_state *prealloc = NULL;
struct rb_node *node;
unsigned long flags;
int err;
int set = 0;
again:
if (!prealloc && (mask & __GFP_WAIT)) {
prealloc = alloc_extent_state(mask);
if (!prealloc)
return -ENOMEM;
}
spin_lock_irqsave(&tree->lock, flags);
/*
* this search will find the extents that end after
* our range starts
*/
node = tree_search(tree, start);
if (!node)
goto out;
state = rb_entry(node, struct extent_state, rb_node);
if (state->start > end)
goto out;
WARN_ON(state->end < start);
/*
* | ---- desired range ---- |
* | state | or
* | ------------- state -------------- |
*
* We need to split the extent we found, and may flip
* bits on second half.
*
* If the extent we found extends past our range, we
* just split and search again. It'll get split again
* the next time though.
*
* If the extent we found is inside our range, we clear
* the desired bit on it.
*/
if (state->start < start) {
if (!prealloc)
prealloc = alloc_extent_state(GFP_ATOMIC);
err = split_state(tree, state, prealloc, start);
BUG_ON(err == -EEXIST);
prealloc = NULL;
if (err)
goto out;
if (state->end <= end) {
start = state->end + 1;
set |= clear_state_bit(tree, state, bits,
wake, delete);
} else {
start = state->start;
}
goto search_again;
}
/*
* | ---- desired range ---- |
* | state |
* We need to split the extent, and clear the bit
* on the first half
*/
if (state->start <= end && state->end > end) {
if (!prealloc)
prealloc = alloc_extent_state(GFP_ATOMIC);
err = split_state(tree, state, prealloc, end + 1);
BUG_ON(err == -EEXIST);
if (wake)
wake_up(&state->wq);
set |= clear_state_bit(tree, prealloc, bits,
wake, delete);
prealloc = NULL;
goto out;
}
start = state->end + 1;
set |= clear_state_bit(tree, state, bits, wake, delete);
goto search_again;
out:
spin_unlock_irqrestore(&tree->lock, flags);
if (prealloc)
free_extent_state(prealloc);
return set;
search_again:
if (start > end)
goto out;
spin_unlock_irqrestore(&tree->lock, flags);
if (mask & __GFP_WAIT)
cond_resched();
goto again;
}
EXPORT_SYMBOL(clear_extent_bit);
static int wait_on_state(struct extent_io_tree *tree,
struct extent_state *state)
{
DEFINE_WAIT(wait);
prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
spin_unlock_irq(&tree->lock);
schedule();
spin_lock_irq(&tree->lock);
finish_wait(&state->wq, &wait);
return 0;
}
/*
* waits for one or more bits to clear on a range in the state tree.
* The range [start, end] is inclusive.
* The tree lock is taken by this function
*/
int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
{
struct extent_state *state;
struct rb_node *node;
spin_lock_irq(&tree->lock);
again:
while (1) {
/*
* this search will find all the extents that end after
* our range starts
*/
node = tree_search(tree, start);
if (!node)
break;
state = rb_entry(node, struct extent_state, rb_node);
if (state->start > end)
goto out;
if (state->state & bits) {
start = state->start;
atomic_inc(&state->refs);
wait_on_state(tree, state);
free_extent_state(state);
goto again;
}
start = state->end + 1;
if (start > end)
break;
if (need_resched()) {
spin_unlock_irq(&tree->lock);
cond_resched();
spin_lock_irq(&tree->lock);
}
}
out:
spin_unlock_irq(&tree->lock);
return 0;
}
EXPORT_SYMBOL(wait_extent_bit);
static void set_state_bits(struct extent_io_tree *tree,
struct extent_state *state,
int bits)
{
if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
u64 range = state->end - state->start + 1;
tree->dirty_bytes += range;
}
set_state_cb(tree, state, bits);
state->state |= bits;
}
/*
* set some bits on a range in the tree. This may require allocations
* or sleeping, so the gfp mask is used to indicate what is allowed.
*
* If 'exclusive' == 1, this will fail with -EEXIST if some part of the
* range already has the desired bits set. The start of the existing
* range is returned in failed_start in this case.
*
* [start, end] is inclusive
* This takes the tree lock.
*/
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits,
int exclusive, u64 *failed_start, gfp_t mask)
{
struct extent_state *state;
struct extent_state *prealloc = NULL;
struct rb_node *node;
unsigned long flags;
int err = 0;
int set;
u64 last_start;
u64 last_end;
again:
if (!prealloc && (mask & __GFP_WAIT)) {
prealloc = alloc_extent_state(mask);
if (!prealloc)
return -ENOMEM;
}
spin_lock_irqsave(&tree->lock, flags);
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(tree, start);
if (!node) {
err = insert_state(tree, prealloc, start, end, bits);
prealloc = NULL;
BUG_ON(err == -EEXIST);
goto out;
}
state = rb_entry(node, struct extent_state, rb_node);
last_start = state->start;
last_end = state->end;
/*
* | ---- desired range ---- |
* | state |
*
* Just lock what we found and keep going
*/
if (state->start == start && state->end <= end) {
set = state->state & bits;
if (set && exclusive) {
*failed_start = state->start;
err = -EEXIST;
goto out;
}
set_state_bits(tree, state, bits);
start = state->end + 1;
merge_state(tree, state);
goto search_again;
}
/*
* | ---- desired range ---- |
* | state |
* or
* | ------------- state -------------- |
*
* We need to split the extent we found, and may flip bits on
* second half.
*
* If the extent we found extends past our
* range, we just split and search again. It'll get split
* again the next time though.
*
* If the extent we found is inside our range, we set the
* desired bit on it.
*/
if (state->start < start) {
set = state->state & bits;
if (exclusive && set) {
*failed_start = start;
err = -EEXIST;
goto out;
}
err = split_state(tree, state, prealloc, start);
BUG_ON(err == -EEXIST);
prealloc = NULL;
if (err)
goto out;
if (state->end <= end) {
set_state_bits(tree, state, bits);
start = state->end + 1;
merge_state(tree, state);
} else {
start = state->start;
}
goto search_again;
}
/*
* | ---- desired range ---- |
* | state | or | state |
*
* There's a hole, we need to insert something in it and
* ignore the extent we found.
*/
if (state->start > start) {
u64 this_end;
if (end < last_start)
this_end = end;
else
this_end = last_start -1;
err = insert_state(tree, prealloc, start, this_end,
bits);
prealloc = NULL;
BUG_ON(err == -EEXIST);
if (err)
goto out;
start = this_end + 1;
goto search_again;
}
/*
* | ---- desired range ---- |
* | state |
* We need to split the extent, and set the bit
* on the first half
*/
if (state->start <= end && state->end > end) {
set = state->state & bits;
if (exclusive && set) {
*failed_start = start;
err = -EEXIST;
goto out;
}
err = split_state(tree, state, prealloc, end + 1);
BUG_ON(err == -EEXIST);
set_state_bits(tree, prealloc, bits);
merge_state(tree, prealloc);
prealloc = NULL;
goto out;
}
goto search_again;
out:
spin_unlock_irqrestore(&tree->lock, flags);
if (prealloc)
free_extent_state(prealloc);
return err;
search_again:
if (start > end)
goto out;
spin_unlock_irqrestore(&tree->lock, flags);
if (mask & __GFP_WAIT)
cond_resched();
goto again;
}
EXPORT_SYMBOL(set_extent_bit);
/* wrappers around set/clear extent bit */
int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
mask);
}
EXPORT_SYMBOL(set_extent_dirty);
int set_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return set_extent_bit(tree, start, end, EXTENT_ORDERED, 0, NULL, mask);
}
EXPORT_SYMBOL(set_extent_ordered);
int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
int bits, gfp_t mask)
{
return set_extent_bit(tree, start, end, bits, 0, NULL,
mask);
}
EXPORT_SYMBOL(set_extent_bits);
int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
int bits, gfp_t mask)
{
return clear_extent_bit(tree, start, end, bits, 0, 0, mask);
}
EXPORT_SYMBOL(clear_extent_bits);
int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return set_extent_bit(tree, start, end,
EXTENT_DELALLOC | EXTENT_DIRTY,
0, NULL, mask);
}
EXPORT_SYMBOL(set_extent_delalloc);
int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return clear_extent_bit(tree, start, end,
EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, mask);
}
EXPORT_SYMBOL(clear_extent_dirty);
int clear_extent_ordered(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return clear_extent_bit(tree, start, end, EXTENT_ORDERED, 1, 0, mask);
}
EXPORT_SYMBOL(clear_extent_ordered);
int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
mask);
}
EXPORT_SYMBOL(set_extent_new);
int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return clear_extent_bit(tree, start, end, EXTENT_NEW, 0, 0, mask);
}
EXPORT_SYMBOL(clear_extent_new);
int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
mask);
}
EXPORT_SYMBOL(set_extent_uptodate);
int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0, mask);
}
EXPORT_SYMBOL(clear_extent_uptodate);
int set_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return set_extent_bit(tree, start, end, EXTENT_WRITEBACK,
0, NULL, mask);
}
EXPORT_SYMBOL(set_extent_writeback);
int clear_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return clear_extent_bit(tree, start, end, EXTENT_WRITEBACK, 1, 0, mask);
}
EXPORT_SYMBOL(clear_extent_writeback);
int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
{
return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
}
EXPORT_SYMBOL(wait_on_extent_writeback);
int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
{
int err;
u64 failed_start;
while (1) {
err = set_extent_bit(tree, start, end, EXTENT_LOCKED, 1,
&failed_start, mask);
if (err == -EEXIST && (mask & __GFP_WAIT)) {
wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
start = failed_start;
} else {
break;
}
WARN_ON(start > end);
}
return err;
}
EXPORT_SYMBOL(lock_extent);
int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, mask);
}
EXPORT_SYMBOL(unlock_extent);
/*
* helper function to set pages and extents in the tree dirty
*/
int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end)
{
unsigned long index = start >> PAGE_CACHE_SHIFT;
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
struct page *page;
while (index <= end_index) {
page = find_get_page(tree->mapping, index);
BUG_ON(!page);
__set_page_dirty_nobuffers(page);
page_cache_release(page);
index++;
}
set_extent_dirty(tree, start, end, GFP_NOFS);
return 0;
}
EXPORT_SYMBOL(set_range_dirty);
/*
* helper function to set both pages and extents in the tree writeback
*/
int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
{
unsigned long index = start >> PAGE_CACHE_SHIFT;
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
struct page *page;
while (index <= end_index) {
page = find_get_page(tree->mapping, index);
BUG_ON(!page);
set_page_writeback(page);
page_cache_release(page);
index++;
}
set_extent_writeback(tree, start, end, GFP_NOFS);
return 0;
}
EXPORT_SYMBOL(set_range_writeback);
int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
u64 *start_ret, u64 *end_ret, int bits)
{
struct rb_node *node;
struct extent_state *state;
int ret = 1;
spin_lock_irq(&tree->lock);
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(tree, start);
if (!node) {
goto out;
}
while(1) {
state = rb_entry(node, struct extent_state, rb_node);
if (state->end >= start && (state->state & bits)) {
*start_ret = state->start;
*end_ret = state->end;
ret = 0;
break;
}
node = rb_next(node);
if (!node)
break;
}
out:
spin_unlock_irq(&tree->lock);
return ret;
}
EXPORT_SYMBOL(find_first_extent_bit);
struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
u64 start, int bits)
{
struct rb_node *node;
struct extent_state *state;
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(tree, start);
if (!node) {
goto out;
}
while(1) {
state = rb_entry(node, struct extent_state, rb_node);
if (state->end >= start && (state->state & bits)) {
return state;
}
node = rb_next(node);
if (!node)
break;
}
out:
return NULL;
}
EXPORT_SYMBOL(find_first_extent_bit_state);
u64 find_lock_delalloc_range(struct extent_io_tree *tree,
u64 *start, u64 *end, u64 max_bytes)
{
struct rb_node *node;
struct extent_state *state;
u64 cur_start = *start;
u64 found = 0;
u64 total_bytes = 0;
spin_lock_irq(&tree->lock);
/*
* this search will find all the extents that end after
* our range starts.
*/
search_again:
node = tree_search(tree, cur_start);
if (!node) {
if (!found)
*end = (u64)-1;
goto out;
}
while(1) {
state = rb_entry(node, struct extent_state, rb_node);
if (found && state->start != cur_start) {
goto out;
}
if (!(state->state & EXTENT_DELALLOC)) {
if (!found)
*end = state->end;
goto out;
}
if (!found) {
struct extent_state *prev_state;
struct rb_node *prev_node = node;
while(1) {
prev_node = rb_prev(prev_node);
if (!prev_node)
break;
prev_state = rb_entry(prev_node,
struct extent_state,
rb_node);
if (!(prev_state->state & EXTENT_DELALLOC))
break;
state = prev_state;
node = prev_node;
}
}
if (state->state & EXTENT_LOCKED) {
DEFINE_WAIT(wait);
atomic_inc(&state->refs);
prepare_to_wait(&state->wq, &wait,
TASK_UNINTERRUPTIBLE);
spin_unlock_irq(&tree->lock);
schedule();
spin_lock_irq(&tree->lock);
finish_wait(&state->wq, &wait);
free_extent_state(state);
goto search_again;
}
set_state_cb(tree, state, EXTENT_LOCKED);
state->state |= EXTENT_LOCKED;
if (!found)
*start = state->start;
found++;
*end = state->end;
cur_start = state->end + 1;
node = rb_next(node);
if (!node)
break;
total_bytes += state->end - state->start + 1;
if (total_bytes >= max_bytes)
break;
}
out:
spin_unlock_irq(&tree->lock);
return found;
}
u64 count_range_bits(struct extent_io_tree *tree,
u64 *start, u64 search_end, u64 max_bytes,
unsigned long bits)
{
struct rb_node *node;
struct extent_state *state;
u64 cur_start = *start;
u64 total_bytes = 0;
int found = 0;
if (search_end <= cur_start) {
printk("search_end %Lu start %Lu\n", search_end, cur_start);
WARN_ON(1);
return 0;
}
spin_lock_irq(&tree->lock);
if (cur_start == 0 && bits == EXTENT_DIRTY) {
total_bytes = tree->dirty_bytes;
goto out;
}
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(tree, cur_start);
if (!node) {
goto out;
}
while(1) {
state = rb_entry(node, struct extent_state, rb_node);
if (state->start > search_end)
break;
if (state->end >= cur_start && (state->state & bits)) {
total_bytes += min(search_end, state->end) + 1 -
max(cur_start, state->start);
if (total_bytes >= max_bytes)
break;
if (!found) {
*start = state->start;
found = 1;
}
}
node = rb_next(node);
if (!node)
break;
}
out:
spin_unlock_irq(&tree->lock);
return total_bytes;
}
/*
* helper function to lock both pages and extents in the tree.
* pages must be locked first.
*/
int lock_range(struct extent_io_tree *tree, u64 start, u64 end)
{
unsigned long index = start >> PAGE_CACHE_SHIFT;
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
struct page *page;
int err;
while (index <= end_index) {
page = grab_cache_page(tree->mapping, index);
if (!page) {
err = -ENOMEM;
goto failed;
}
if (IS_ERR(page)) {
err = PTR_ERR(page);
goto failed;
}
index++;
}
lock_extent(tree, start, end, GFP_NOFS);
return 0;
failed:
/*
* we failed above in getting the page at 'index', so we undo here
* up to but not including the page at 'index'
*/
end_index = index;
index = start >> PAGE_CACHE_SHIFT;
while (index < end_index) {
page = find_get_page(tree->mapping, index);
unlock_page(page);
page_cache_release(page);
index++;
}
return err;
}
EXPORT_SYMBOL(lock_range);
/*
* helper function to unlock both pages and extents in the tree.
*/
int unlock_range(struct extent_io_tree *tree, u64 start, u64 end)
{
unsigned long index = start >> PAGE_CACHE_SHIFT;
unsigned long end_index = end >> PAGE_CACHE_SHIFT;
struct page *page;
while (index <= end_index) {
page = find_get_page(tree->mapping, index);
unlock_page(page);
page_cache_release(page);
index++;
}
unlock_extent(tree, start, end, GFP_NOFS);
return 0;
}
EXPORT_SYMBOL(unlock_range);
int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
{
struct rb_node *node;
struct extent_state *state;
int ret = 0;
spin_lock_irq(&tree->lock);
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(tree, start);
if (!node) {
ret = -ENOENT;
goto out;
}
state = rb_entry(node, struct extent_state, rb_node);
if (state->start != start) {
ret = -ENOENT;
goto out;
}
state->private = private;
out:
spin_unlock_irq(&tree->lock);
return ret;
}
int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
{
struct rb_node *node;
struct extent_state *state;
int ret = 0;
spin_lock_irq(&tree->lock);
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(tree, start);
if (!node) {
ret = -ENOENT;
goto out;
}
state = rb_entry(node, struct extent_state, rb_node);
if (state->start != start) {
ret = -ENOENT;
goto out;
}
*private = state->private;
out:
spin_unlock_irq(&tree->lock);
return ret;
}
/*
* searches a range in the state tree for a given mask.
* If 'filled' == 1, this returns 1 only if every extent in the tree
* has the bits set. Otherwise, 1 is returned if any bit in the
* range is found set.
*/
int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
int bits, int filled)
{
struct extent_state *state = NULL;
struct rb_node *node;
int bitset = 0;
unsigned long flags;
spin_lock_irqsave(&tree->lock, flags);
node = tree_search(tree, start);
while (node && start <= end) {
state = rb_entry(node, struct extent_state, rb_node);
if (filled && state->start > start) {
bitset = 0;
break;
}
if (state->start > end)
break;
if (state->state & bits) {
bitset = 1;
if (!filled)
break;
} else if (filled) {
bitset = 0;
break;
}
start = state->end + 1;
if (start > end)
break;
node = rb_next(node);
if (!node) {
if (filled)
bitset = 0;
break;
}
}
spin_unlock_irqrestore(&tree->lock, flags);
return bitset;
}
EXPORT_SYMBOL(test_range_bit);
/*
* helper function to set a given page up to date if all the
* extents in the tree for that page are up to date
*/
static int check_page_uptodate(struct extent_io_tree *tree,
struct page *page)
{
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 end = start + PAGE_CACHE_SIZE - 1;
if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
SetPageUptodate(page);
return 0;
}
/*
* helper function to unlock a page if all the extents in the tree
* for that page are unlocked
*/
static int check_page_locked(struct extent_io_tree *tree,
struct page *page)
{
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 end = start + PAGE_CACHE_SIZE - 1;
if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
unlock_page(page);
return 0;
}
/*
* helper function to end page writeback if all the extents
* in the tree for that page are done with writeback
*/
static int check_page_writeback(struct extent_io_tree *tree,
struct page *page)
{
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 end = start + PAGE_CACHE_SIZE - 1;
if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0))
end_page_writeback(page);
return 0;
}
/* lots and lots of room for performance fixes in the end_bio funcs */
/*
* after a writepage IO is done, we need to:
* clear the uptodate bits on error
* clear the writeback bits in the extent tree for this IO
* end_page_writeback if the page has no more pending IO
*
* Scheduling is not allowed, so the extent state tree is expected
* to have one and only one object corresponding to this IO.
*/
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
static void end_bio_extent_writepage(struct bio *bio, int err)
#else
static int end_bio_extent_writepage(struct bio *bio,
unsigned int bytes_done, int err)
#endif
{
int uptodate = err == 0;
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
struct extent_state *state = bio->bi_private;
struct extent_io_tree *tree = state->tree;
struct rb_node *node;
u64 start;
u64 end;
u64 cur;
int whole_page;
int ret;
unsigned long flags;
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
if (bio->bi_size)
return 1;
#endif
do {
struct page *page = bvec->bv_page;
start = ((u64)page->index << PAGE_CACHE_SHIFT) +
bvec->bv_offset;
end = start + bvec->bv_len - 1;
if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
whole_page = 1;
else
whole_page = 0;
if (--bvec >= bio->bi_io_vec)
prefetchw(&bvec->bv_page->flags);
if (tree->ops && tree->ops->writepage_end_io_hook) {
ret = tree->ops->writepage_end_io_hook(page, start,
end, state, uptodate);
if (ret)
uptodate = 0;
}
if (!uptodate && tree->ops &&
tree->ops->writepage_io_failed_hook) {
ret = tree->ops->writepage_io_failed_hook(bio, page,
start, end, state);
if (ret == 0) {
state = NULL;
uptodate = (err == 0);
continue;
}
}
if (!uptodate) {
clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
ClearPageUptodate(page);
SetPageError(page);
}
/*
* bios can get merged in funny ways, and so we need to
* be careful with the state variable. We know the
* state won't be merged with others because it has
* WRITEBACK set, but we can't be sure each biovec is
* sequential in the file. So, if our cached state
* doesn't match the expected end, search the tree
* for the correct one.
*/
spin_lock_irqsave(&tree->lock, flags);
if (!state || state->end != end) {
state = NULL;
node = __etree_search(tree, start, NULL, NULL);
if (node) {
state = rb_entry(node, struct extent_state,
rb_node);
if (state->end != end ||
!(state->state & EXTENT_WRITEBACK))
state = NULL;
}
if (!state) {
spin_unlock_irqrestore(&tree->lock, flags);
clear_extent_writeback(tree, start,
end, GFP_ATOMIC);
goto next_io;
}
}
cur = end;
while(1) {
struct extent_state *clear = state;
cur = state->start;
node = rb_prev(&state->rb_node);
if (node) {
state = rb_entry(node,
struct extent_state,
rb_node);
} else {
state = NULL;
}
clear_state_bit(tree, clear, EXTENT_WRITEBACK,
1, 0);
if (cur == start)
break;
if (cur < start) {
WARN_ON(1);
break;
}
if (!node)
break;
}
/* before releasing the lock, make sure the next state
* variable has the expected bits set and corresponds
* to the correct offsets in the file
*/
if (state && (state->end + 1 != start ||
!(state->state & EXTENT_WRITEBACK))) {
state = NULL;
}
spin_unlock_irqrestore(&tree->lock, flags);
next_io:
if (whole_page)
end_page_writeback(page);
else
check_page_writeback(tree, page);
} while (bvec >= bio->bi_io_vec);
bio_put(bio);
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
return 0;
#endif
}
/*
* after a readpage IO is done, we need to:
* clear the uptodate bits on error
* set the uptodate bits if things worked
* set the page up to date if all extents in the tree are uptodate
* clear the lock bit in the extent tree
* unlock the page if there are no other extents locked for it
*
* Scheduling is not allowed, so the extent state tree is expected
* to have one and only one object corresponding to this IO.
*/
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
static void end_bio_extent_readpage(struct bio *bio, int err)
#else
static int end_bio_extent_readpage(struct bio *bio,
unsigned int bytes_done, int err)
#endif
{
int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
struct extent_state *state = bio->bi_private;
struct extent_io_tree *tree = state->tree;
struct rb_node *node;
u64 start;
u64 end;
u64 cur;
unsigned long flags;
int whole_page;
int ret;
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
if (bio->bi_size)
return 1;
#endif
do {
struct page *page = bvec->bv_page;
start = ((u64)page->index << PAGE_CACHE_SHIFT) +
bvec->bv_offset;
end = start + bvec->bv_len - 1;
if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
whole_page = 1;
else
whole_page = 0;
if (--bvec >= bio->bi_io_vec)
prefetchw(&bvec->bv_page->flags);
if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
ret = tree->ops->readpage_end_io_hook(page, start, end,
state);
if (ret)
uptodate = 0;
}
if (!uptodate && tree->ops &&
tree->ops->readpage_io_failed_hook) {
ret = tree->ops->readpage_io_failed_hook(bio, page,
start, end, state);
if (ret == 0) {
state = NULL;
uptodate =
test_bit(BIO_UPTODATE, &bio->bi_flags);
continue;
}
}
spin_lock_irqsave(&tree->lock, flags);
if (!state || state->end != end) {
state = NULL;
node = __etree_search(tree, start, NULL, NULL);
if (node) {
state = rb_entry(node, struct extent_state,
rb_node);
if (state->end != end ||
!(state->state & EXTENT_LOCKED))
state = NULL;
}
if (!state) {
spin_unlock_irqrestore(&tree->lock, flags);
if (uptodate)
set_extent_uptodate(tree, start, end,
GFP_ATOMIC);
unlock_extent(tree, start, end, GFP_ATOMIC);
goto next_io;
}
}
cur = end;
while(1) {
struct extent_state *clear = state;
cur = state->start;
node = rb_prev(&state->rb_node);
if (node) {
state = rb_entry(node,
struct extent_state,
rb_node);
} else {
state = NULL;
}
if (uptodate) {
set_state_cb(tree, clear, EXTENT_UPTODATE);
clear->state |= EXTENT_UPTODATE;
}
clear_state_bit(tree, clear, EXTENT_LOCKED,
1, 0);
if (cur == start)
break;
if (cur < start) {
WARN_ON(1);
break;
}
if (!node)
break;
}
/* before releasing the lock, make sure the next state
* variable has the expected bits set and corresponds
* to the correct offsets in the file
*/
if (state && (state->end + 1 != start ||
!(state->state & EXTENT_LOCKED))) {
state = NULL;
}
spin_unlock_irqrestore(&tree->lock, flags);
next_io:
if (whole_page) {
if (uptodate) {
SetPageUptodate(page);
} else {
ClearPageUptodate(page);
SetPageError(page);
}
unlock_page(page);
} else {
if (uptodate) {
check_page_uptodate(tree, page);
} else {
ClearPageUptodate(page);
SetPageError(page);
}
check_page_locked(tree, page);
}
} while (bvec >= bio->bi_io_vec);
bio_put(bio);
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
return 0;
#endif
}
/*
* IO done from prepare_write is pretty simple, we just unlock
* the structs in the extent tree when done, and set the uptodate bits
* as appropriate.
*/
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
static void end_bio_extent_preparewrite(struct bio *bio, int err)
#else
static int end_bio_extent_preparewrite(struct bio *bio,
unsigned int bytes_done, int err)
#endif
{
const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
struct extent_state *state = bio->bi_private;
struct extent_io_tree *tree = state->tree;
u64 start;
u64 end;
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
if (bio->bi_size)
return 1;
#endif
do {
struct page *page = bvec->bv_page;
start = ((u64)page->index << PAGE_CACHE_SHIFT) +
bvec->bv_offset;
end = start + bvec->bv_len - 1;
if (--bvec >= bio->bi_io_vec)
prefetchw(&bvec->bv_page->flags);
if (uptodate) {
set_extent_uptodate(tree, start, end, GFP_ATOMIC);
} else {
ClearPageUptodate(page);
SetPageError(page);
}
unlock_extent(tree, start, end, GFP_ATOMIC);
} while (bvec >= bio->bi_io_vec);
bio_put(bio);
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
return 0;
#endif
}
static struct bio *
extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
gfp_t gfp_flags)
{
struct bio *bio;
bio = bio_alloc(gfp_flags, nr_vecs);
if (bio == NULL && (current->flags & PF_MEMALLOC)) {
while (!bio && (nr_vecs /= 2))
bio = bio_alloc(gfp_flags, nr_vecs);
}
if (bio) {
bio->bi_size = 0;
bio->bi_bdev = bdev;
bio->bi_sector = first_sector;
}
return bio;
}
static int submit_one_bio(int rw, struct bio *bio, int mirror_num)
{
int ret = 0;
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
struct page *page = bvec->bv_page;
struct extent_io_tree *tree = bio->bi_private;
struct rb_node *node;
struct extent_state *state;
u64 start;
u64 end;
start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
end = start + bvec->bv_len - 1;
spin_lock_irq(&tree->lock);
node = __etree_search(tree, start, NULL, NULL);
BUG_ON(!node);
state = rb_entry(node, struct extent_state, rb_node);
while(state->end < end) {
node = rb_next(node);
state = rb_entry(node, struct extent_state, rb_node);
}
BUG_ON(state->end != end);
spin_unlock_irq(&tree->lock);
bio->bi_private = state;
bio_get(bio);
if (tree->ops && tree->ops->submit_bio_hook)
tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
mirror_num);
else
submit_bio(rw, bio);
if (bio_flagged(bio, BIO_EOPNOTSUPP))
ret = -EOPNOTSUPP;
bio_put(bio);
return ret;
}
static int submit_extent_page(int rw, struct extent_io_tree *tree,
struct page *page, sector_t sector,
size_t size, unsigned long offset,
struct block_device *bdev,
struct bio **bio_ret,
unsigned long max_pages,
bio_end_io_t end_io_func,
int mirror_num)
{
int ret = 0;
struct bio *bio;
int nr;
if (bio_ret && *bio_ret) {
bio = *bio_ret;
if (bio->bi_sector + (bio->bi_size >> 9) != sector ||
(tree->ops && tree->ops->merge_bio_hook &&
tree->ops->merge_bio_hook(page, offset, size, bio)) ||
bio_add_page(bio, page, size, offset) < size) {
ret = submit_one_bio(rw, bio, mirror_num);
bio = NULL;
} else {
return 0;
}
}
nr = bio_get_nr_vecs(bdev);
bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
if (!bio) {
printk("failed to allocate bio nr %d\n", nr);
}
bio_add_page(bio, page, size, offset);
bio->bi_end_io = end_io_func;
bio->bi_private = tree;
if (bio_ret) {
*bio_ret = bio;
} else {
ret = submit_one_bio(rw, bio, mirror_num);
}
return ret;
}
void set_page_extent_mapped(struct page *page)
{
if (!PagePrivate(page)) {
SetPagePrivate(page);
WARN_ON(!page->mapping->a_ops->invalidatepage);
set_page_private(page, EXTENT_PAGE_PRIVATE);
page_cache_get(page);
}
}
void set_page_extent_head(struct page *page, unsigned long len)
{
set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
}
/*
* basic readpage implementation. Locked extent state structs are inserted
* into the tree that are removed when the IO is done (by the end_io
* handlers)
*/
static int __extent_read_full_page(struct extent_io_tree *tree,
struct page *page,
get_extent_t *get_extent,
struct bio **bio, int mirror_num)
{
struct inode *inode = page->mapping->host;
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 page_end = start + PAGE_CACHE_SIZE - 1;
u64 end;
u64 cur = start;
u64 extent_offset;
u64 last_byte = i_size_read(inode);
u64 block_start;
u64 cur_end;
sector_t sector;
struct extent_map *em;
struct block_device *bdev;
int ret;
int nr = 0;
size_t page_offset = 0;
size_t iosize;
size_t blocksize = inode->i_sb->s_blocksize;
set_page_extent_mapped(page);
end = page_end;
lock_extent(tree, start, end, GFP_NOFS);
while (cur <= end) {
if (cur >= last_byte) {
char *userpage;
iosize = PAGE_CACHE_SIZE - page_offset;
userpage = kmap_atomic(page, KM_USER0);
memset(userpage + page_offset, 0, iosize);
flush_dcache_page(page);
kunmap_atomic(userpage, KM_USER0);
set_extent_uptodate(tree, cur, cur + iosize - 1,
GFP_NOFS);
unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
break;
}
em = get_extent(inode, page, page_offset, cur,
end - cur + 1, 0);
if (IS_ERR(em) || !em) {
SetPageError(page);
unlock_extent(tree, cur, end, GFP_NOFS);
break;
}
extent_offset = cur - em->start;
if (extent_map_end(em) <= cur) {
printk("bad mapping em [%Lu %Lu] cur %Lu\n", em->start, extent_map_end(em), cur);
}
BUG_ON(extent_map_end(em) <= cur);
if (end < cur) {
printk("2bad mapping end %Lu cur %Lu\n", end, cur);
}
BUG_ON(end < cur);
iosize = min(extent_map_end(em) - cur, end - cur + 1);
cur_end = min(extent_map_end(em) - 1, end);
iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
sector = (em->block_start + extent_offset) >> 9;
bdev = em->bdev;
block_start = em->block_start;
free_extent_map(em);
em = NULL;
/* we've found a hole, just zero and go on */
if (block_start == EXTENT_MAP_HOLE) {
char *userpage;
userpage = kmap_atomic(page, KM_USER0);
memset(userpage + page_offset, 0, iosize);
flush_dcache_page(page);
kunmap_atomic(userpage, KM_USER0);
set_extent_uptodate(tree, cur, cur + iosize - 1,
GFP_NOFS);
unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
cur = cur + iosize;
page_offset += iosize;
continue;
}
/* the get_extent function already copied into the page */
if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
cur = cur + iosize;
page_offset += iosize;
continue;
}
/* we have an inline extent but it didn't get marked up
* to date. Error out
*/
if (block_start == EXTENT_MAP_INLINE) {
SetPageError(page);
unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
cur = cur + iosize;
page_offset += iosize;
continue;
}
ret = 0;
if (tree->ops && tree->ops->readpage_io_hook) {
ret = tree->ops->readpage_io_hook(page, cur,
cur + iosize - 1);
}
if (!ret) {
unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
nr -= page->index;
ret = submit_extent_page(READ, tree, page,
sector, iosize, page_offset,
bdev, bio, nr,
end_bio_extent_readpage, mirror_num);
}
if (ret)
SetPageError(page);
cur = cur + iosize;
page_offset += iosize;
nr++;
}
if (!nr) {
if (!PageError(page))
SetPageUptodate(page);
unlock_page(page);
}
return 0;
}
int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
get_extent_t *get_extent)
{
struct bio *bio = NULL;
int ret;
ret = __extent_read_full_page(tree, page, get_extent, &bio, 0);
if (bio)
submit_one_bio(READ, bio, 0);
return ret;
}
EXPORT_SYMBOL(extent_read_full_page);
/*
* the writepage semantics are similar to regular writepage. extent
* records are inserted to lock ranges in the tree, and as dirty areas
* are found, they are marked writeback. Then the lock bits are removed
* and the end_io handler clears the writeback ranges
*/
static int __extent_writepage(struct page *page, struct writeback_control *wbc,
void *data)
{
struct inode *inode = page->mapping->host;
struct extent_page_data *epd = data;
struct extent_io_tree *tree = epd->tree;
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 delalloc_start;
u64 page_end = start + PAGE_CACHE_SIZE - 1;
u64 end;
u64 cur = start;
u64 extent_offset;
u64 last_byte = i_size_read(inode);
u64 block_start;
u64 iosize;
u64 unlock_start;
sector_t sector;
struct extent_map *em;
struct block_device *bdev;
int ret;
int nr = 0;
size_t pg_offset = 0;
size_t blocksize;
loff_t i_size = i_size_read(inode);
unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
u64 nr_delalloc;
u64 delalloc_end;
WARN_ON(!PageLocked(page));
pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
if (page->index > end_index ||
(page->index == end_index && !pg_offset)) {
page->mapping->a_ops->invalidatepage(page, 0);
unlock_page(page);
return 0;
}
if (page->index == end_index) {
char *userpage;
userpage = kmap_atomic(page, KM_USER0);
memset(userpage + pg_offset, 0,
PAGE_CACHE_SIZE - pg_offset);
kunmap_atomic(userpage, KM_USER0);
flush_dcache_page(page);
}
pg_offset = 0;
set_page_extent_mapped(page);
delalloc_start = start;
delalloc_end = 0;
while(delalloc_end < page_end) {
nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start,
&delalloc_end,
128 * 1024 * 1024);
if (nr_delalloc == 0) {
delalloc_start = delalloc_end + 1;
continue;
}
tree->ops->fill_delalloc(inode, delalloc_start,
delalloc_end);
clear_extent_bit(tree, delalloc_start,
delalloc_end,
EXTENT_LOCKED | EXTENT_DELALLOC,
1, 0, GFP_NOFS);
delalloc_start = delalloc_end + 1;
}
lock_extent(tree, start, page_end, GFP_NOFS);
unlock_start = start;
if (tree->ops && tree->ops->writepage_start_hook) {
ret = tree->ops->writepage_start_hook(page, start, page_end);
if (ret == -EAGAIN) {
unlock_extent(tree, start, page_end, GFP_NOFS);
redirty_page_for_writepage(wbc, page);
unlock_page(page);
return 0;
}
}
end = page_end;
if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
printk("found delalloc bits after lock_extent\n");
}
if (last_byte <= start) {
clear_extent_dirty(tree, start, page_end, GFP_NOFS);
unlock_extent(tree, start, page_end, GFP_NOFS);
if (tree->ops && tree->ops->writepage_end_io_hook)
tree->ops->writepage_end_io_hook(page, start,
page_end, NULL, 1);
unlock_start = page_end + 1;
goto done;
}
set_extent_uptodate(tree, start, page_end, GFP_NOFS);
blocksize = inode->i_sb->s_blocksize;
while (cur <= end) {
if (cur >= last_byte) {
clear_extent_dirty(tree, cur, page_end, GFP_NOFS);
unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
if (tree->ops && tree->ops->writepage_end_io_hook)
tree->ops->writepage_end_io_hook(page, cur,
page_end, NULL, 1);
unlock_start = page_end + 1;
break;
}
em = epd->get_extent(inode, page, pg_offset, cur,
end - cur + 1, 1);
if (IS_ERR(em) || !em) {
SetPageError(page);
break;
}
extent_offset = cur - em->start;
BUG_ON(extent_map_end(em) <= cur);
BUG_ON(end < cur);
iosize = min(extent_map_end(em) - cur, end - cur + 1);
iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
sector = (em->block_start + extent_offset) >> 9;
bdev = em->bdev;
block_start = em->block_start;
free_extent_map(em);
em = NULL;
if (block_start == EXTENT_MAP_HOLE ||
block_start == EXTENT_MAP_INLINE) {
clear_extent_dirty(tree, cur,
cur + iosize - 1, GFP_NOFS);
unlock_extent(tree, unlock_start, cur + iosize -1,
GFP_NOFS);
if (tree->ops && tree->ops->writepage_end_io_hook)
tree->ops->writepage_end_io_hook(page, cur,
cur + iosize - 1,
NULL, 1);
cur = cur + iosize;
pg_offset += iosize;
unlock_start = cur;
continue;
}
/* leave this out until we have a page_mkwrite call */
if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
EXTENT_DIRTY, 0)) {
cur = cur + iosize;
pg_offset += iosize;
continue;
}
clear_extent_dirty(tree, cur, cur + iosize - 1, GFP_NOFS);
if (tree->ops && tree->ops->writepage_io_hook) {
ret = tree->ops->writepage_io_hook(page, cur,
cur + iosize - 1);
} else {
ret = 0;
}
if (ret) {
SetPageError(page);
} else {
unsigned long max_nr = end_index + 1;
set_range_writeback(tree, cur, cur + iosize - 1);
if (!PageWriteback(page)) {
printk("warning page %lu not writeback, "
"cur %llu end %llu\n", page->index,
(unsigned long long)cur,
(unsigned long long)end);
}
ret = submit_extent_page(WRITE, tree, page, sector,
iosize, pg_offset, bdev,
&epd->bio, max_nr,
end_bio_extent_writepage, 0);
if (ret)
SetPageError(page);
}
cur = cur + iosize;
pg_offset += iosize;
nr++;
}
done:
if (nr == 0) {
/* make sure the mapping tag for page dirty gets cleared */
set_page_writeback(page);
end_page_writeback(page);
}
if (unlock_start <= page_end)
unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
unlock_page(page);
return 0;
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
/* Taken directly from 2.6.23 for 2.6.18 back port */
typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
void *data);
/**
* write_cache_pages - walk the list of dirty pages of the given address space
* and write all of them.
* @mapping: address space structure to write
* @wbc: subtract the number of written pages from *@wbc->nr_to_write
* @writepage: function called for each page
* @data: data passed to writepage function
*
* If a page is already under I/O, write_cache_pages() skips it, even
* if it's dirty. This is desirable behaviour for memory-cleaning writeback,
* but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
* and msync() need to guarantee that all the data which was dirty at the time
* the call was made get new I/O started against them. If wbc->sync_mode is
* WB_SYNC_ALL then we were called for data integrity and we must wait for
* existing IO to complete.
*/
static int write_cache_pages(struct address_space *mapping,
struct writeback_control *wbc, writepage_t writepage,
void *data)
{
struct backing_dev_info *bdi = mapping->backing_dev_info;
int ret = 0;
int done = 0;
struct pagevec pvec;
int nr_pages;
pgoff_t index;
pgoff_t end; /* Inclusive */
int scanned = 0;
int range_whole = 0;
if (wbc->nonblocking && bdi_write_congested(bdi)) {
wbc->encountered_congestion = 1;
return 0;
}
pagevec_init(&pvec, 0);
if (wbc->range_cyclic) {
index = mapping->writeback_index; /* Start from prev offset */
end = -1;
} else {
index = wbc->range_start >> PAGE_CACHE_SHIFT;
end = wbc->range_end >> PAGE_CACHE_SHIFT;
if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
range_whole = 1;
scanned = 1;
}
retry:
while (!done && (index <= end) &&
(nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
PAGECACHE_TAG_DIRTY,
min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
unsigned i;
scanned = 1;
for (i = 0; i < nr_pages; i++) {
struct page *page = pvec.pages[i];
/*
* At this point we hold neither mapping->tree_lock nor
* lock on the page itself: the page may be truncated or
* invalidated (changing page->mapping to NULL), or even
* swizzled back from swapper_space to tmpfs file
* mapping
*/
lock_page(page);
if (unlikely(page->mapping != mapping)) {
unlock_page(page);
continue;
}
if (!wbc->range_cyclic && page->index > end) {
done = 1;
unlock_page(page);
continue;
}
if (wbc->sync_mode != WB_SYNC_NONE)
wait_on_page_writeback(page);
if (PageWriteback(page) ||
!clear_page_dirty_for_io(page)) {
unlock_page(page);
continue;
}
ret = (*writepage)(page, wbc, data);
if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
unlock_page(page);
ret = 0;
}
if (ret || (--(wbc->nr_to_write) <= 0))
done = 1;
if (wbc->nonblocking && bdi_write_congested(bdi)) {
wbc->encountered_congestion = 1;
done = 1;
}
}
pagevec_release(&pvec);
cond_resched();
}
if (!scanned && !done) {
/*
* We hit the last page and there is more work to be done: wrap
* back to the start of the file
*/
scanned = 1;
index = 0;
goto retry;
}
if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
mapping->writeback_index = index;
return ret;
}
#endif
int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
get_extent_t *get_extent,
struct writeback_control *wbc)
{
int ret;
struct address_space *mapping = page->mapping;
struct extent_page_data epd = {
.bio = NULL,
.tree = tree,
.get_extent = get_extent,
};
struct writeback_control wbc_writepages = {
.bdi = wbc->bdi,
.sync_mode = WB_SYNC_NONE,
.older_than_this = NULL,
.nr_to_write = 64,
.range_start = page_offset(page) + PAGE_CACHE_SIZE,
.range_end = (loff_t)-1,
};
ret = __extent_writepage(page, wbc, &epd);
write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd);
if (epd.bio) {
submit_one_bio(WRITE, epd.bio, 0);
}
return ret;
}
EXPORT_SYMBOL(extent_write_full_page);
int extent_writepages(struct extent_io_tree *tree,
struct address_space *mapping,
get_extent_t *get_extent,
struct writeback_control *wbc)
{
int ret = 0;
struct extent_page_data epd = {
.bio = NULL,
.tree = tree,
.get_extent = get_extent,
};
ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd);
if (epd.bio) {
submit_one_bio(WRITE, epd.bio, 0);
}
return ret;
}
EXPORT_SYMBOL(extent_writepages);
int extent_readpages(struct extent_io_tree *tree,
struct address_space *mapping,
struct list_head *pages, unsigned nr_pages,
get_extent_t get_extent)
{
struct bio *bio = NULL;
unsigned page_idx;
struct pagevec pvec;
pagevec_init(&pvec, 0);
for (page_idx = 0; page_idx < nr_pages; page_idx++) {
struct page *page = list_entry(pages->prev, struct page, lru);
prefetchw(&page->flags);
list_del(&page->lru);
/*
* what we want to do here is call add_to_page_cache_lru,
* but that isn't exported, so we reproduce it here
*/
if (!add_to_page_cache(page, mapping,
page->index, GFP_KERNEL)) {
/* open coding of lru_cache_add, also not exported */
page_cache_get(page);
if (!pagevec_add(&pvec, page))
__pagevec_lru_add(&pvec);
__extent_read_full_page(tree, page, get_extent,
&bio, 0);
}
page_cache_release(page);
}
if (pagevec_count(&pvec))
__pagevec_lru_add(&pvec);
BUG_ON(!list_empty(pages));
if (bio)
submit_one_bio(READ, bio, 0);
return 0;
}
EXPORT_SYMBOL(extent_readpages);
/*
* basic invalidatepage code, this waits on any locked or writeback
* ranges corresponding to the page, and then deletes any extent state
* records from the tree
*/
int extent_invalidatepage(struct extent_io_tree *tree,
struct page *page, unsigned long offset)
{
u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
u64 end = start + PAGE_CACHE_SIZE - 1;
size_t blocksize = page->mapping->host->i_sb->s_blocksize;
start += (offset + blocksize -1) & ~(blocksize - 1);
if (start > end)
return 0;
lock_extent(tree, start, end, GFP_NOFS);
wait_on_extent_writeback(tree, start, end);
clear_extent_bit(tree, start, end,
EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
1, 1, GFP_NOFS);
return 0;
}
EXPORT_SYMBOL(extent_invalidatepage);
/*
* simple commit_write call, set_range_dirty is used to mark both
* the pages and the extent records as dirty
*/
int extent_commit_write(struct extent_io_tree *tree,
struct inode *inode, struct page *page,
unsigned from, unsigned to)
{
loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
set_page_extent_mapped(page);
set_page_dirty(page);
if (pos > inode->i_size) {
i_size_write(inode, pos);
mark_inode_dirty(inode);
}
return 0;
}
EXPORT_SYMBOL(extent_commit_write);
int extent_prepare_write(struct extent_io_tree *tree,
struct inode *inode, struct page *page,
unsigned from, unsigned to, get_extent_t *get_extent)
{
u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
u64 block_start;
u64 orig_block_start;
u64 block_end;
u64 cur_end;
struct extent_map *em;
unsigned blocksize = 1 << inode->i_blkbits;
size_t page_offset = 0;
size_t block_off_start;
size_t block_off_end;
int err = 0;
int iocount = 0;
int ret = 0;
int isnew;
set_page_extent_mapped(page);
block_start = (page_start + from) & ~((u64)blocksize - 1);
block_end = (page_start + to - 1) | (blocksize - 1);
orig_block_start = block_start;
lock_extent(tree, page_start, page_end, GFP_NOFS);
while(block_start <= block_end) {
em = get_extent(inode, page, page_offset, block_start,
block_end - block_start + 1, 1);
if (IS_ERR(em) || !em) {
goto err;
}
cur_end = min(block_end, extent_map_end(em) - 1);
block_off_start = block_start & (PAGE_CACHE_SIZE - 1);
block_off_end = block_off_start + blocksize;
isnew = clear_extent_new(tree, block_start, cur_end, GFP_NOFS);
if (!PageUptodate(page) && isnew &&
(block_off_end > to || block_off_start < from)) {
void *kaddr;
kaddr = kmap_atomic(page, KM_USER0);
if (block_off_end > to)
memset(kaddr + to, 0, block_off_end - to);
if (block_off_start < from)
memset(kaddr + block_off_start, 0,
from - block_off_start);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
}
if ((em->block_start != EXTENT_MAP_HOLE &&
em->block_start != EXTENT_MAP_INLINE) &&
!isnew && !PageUptodate(page) &&
(block_off_end > to || block_off_start < from) &&
!test_range_bit(tree, block_start, cur_end,
EXTENT_UPTODATE, 1)) {
u64 sector;
u64 extent_offset = block_start - em->start;
size_t iosize;
sector = (em->block_start + extent_offset) >> 9;
iosize = (cur_end - block_start + blocksize) &
~((u64)blocksize - 1);
/*
* we've already got the extent locked, but we
* need to split the state such that our end_bio
* handler can clear the lock.
*/
set_extent_bit(tree, block_start,
block_start + iosize - 1,
EXTENT_LOCKED, 0, NULL, GFP_NOFS);
ret = submit_extent_page(READ, tree, page,
sector, iosize, page_offset, em->bdev,
NULL, 1,
end_bio_extent_preparewrite, 0);
iocount++;
block_start = block_start + iosize;
} else {
set_extent_uptodate(tree, block_start, cur_end,
GFP_NOFS);
unlock_extent(tree, block_start, cur_end, GFP_NOFS);
block_start = cur_end + 1;
}
page_offset = block_start & (PAGE_CACHE_SIZE - 1);
free_extent_map(em);
}
if (iocount) {
wait_extent_bit(tree, orig_block_start,
block_end, EXTENT_LOCKED);
}
check_page_uptodate(tree, page);
err:
/* FIXME, zero out newly allocated blocks on error */
return err;
}
EXPORT_SYMBOL(extent_prepare_write);
/*
* a helper for releasepage, this tests for areas of the page that
* are locked or under IO and drops the related state bits if it is safe
* to drop the page.
*/
int try_release_extent_state(struct extent_map_tree *map,
struct extent_io_tree *tree, struct page *page,
gfp_t mask)
{
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 end = start + PAGE_CACHE_SIZE - 1;
int ret = 1;
if (test_range_bit(tree, start, end,
EXTENT_IOBITS | EXTENT_ORDERED, 0))
ret = 0;
else {
if ((mask & GFP_NOFS) == GFP_NOFS)
mask = GFP_NOFS;
clear_extent_bit(tree, start, end, EXTENT_UPTODATE,
1, 1, mask);
}
return ret;
}
EXPORT_SYMBOL(try_release_extent_state);
/*
* a helper for releasepage. As long as there are no locked extents
* in the range corresponding to the page, both state records and extent
* map records are removed
*/
int try_release_extent_mapping(struct extent_map_tree *map,
struct extent_io_tree *tree, struct page *page,
gfp_t mask)
{
struct extent_map *em;
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 end = start + PAGE_CACHE_SIZE - 1;
if ((mask & __GFP_WAIT) &&
page->mapping->host->i_size > 16 * 1024 * 1024) {
u64 len;
while (start <= end) {
len = end - start + 1;
spin_lock(&map->lock);
em = lookup_extent_mapping(map, start, len);
if (!em || IS_ERR(em)) {
spin_unlock(&map->lock);
break;
}
if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
em->start != start) {
spin_unlock(&map->lock);
free_extent_map(em);
break;
}
if (!test_range_bit(tree, em->start,
extent_map_end(em) - 1,
EXTENT_LOCKED, 0)) {
remove_extent_mapping(map, em);
/* once for the rb tree */
free_extent_map(em);
}
start = extent_map_end(em);
spin_unlock(&map->lock);
/* once for us */
free_extent_map(em);
}
}
return try_release_extent_state(map, tree, page, mask);
}
EXPORT_SYMBOL(try_release_extent_mapping);
sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
get_extent_t *get_extent)
{
struct inode *inode = mapping->host;
u64 start = iblock << inode->i_blkbits;
sector_t sector = 0;
struct extent_map *em;
em = get_extent(inode, NULL, 0, start, (1 << inode->i_blkbits), 0);
if (!em || IS_ERR(em))
return 0;
if (em->block_start == EXTENT_MAP_INLINE ||
em->block_start == EXTENT_MAP_HOLE)
goto out;
sector = (em->block_start + start - em->start) >> inode->i_blkbits;
out:
free_extent_map(em);
return sector;
}
static int add_lru(struct extent_io_tree *tree, struct extent_buffer *eb)
{
if (list_empty(&eb->lru)) {
extent_buffer_get(eb);
list_add(&eb->lru, &tree->buffer_lru);
tree->lru_size++;
if (tree->lru_size >= BUFFER_LRU_MAX) {
struct extent_buffer *rm;
rm = list_entry(tree->buffer_lru.prev,
struct extent_buffer, lru);
tree->lru_size--;
list_del_init(&rm->lru);
free_extent_buffer(rm);
}
} else
list_move(&eb->lru, &tree->buffer_lru);
return 0;
}
static struct extent_buffer *find_lru(struct extent_io_tree *tree,
u64 start, unsigned long len)
{
struct list_head *lru = &tree->buffer_lru;
struct list_head *cur = lru->next;
struct extent_buffer *eb;
if (list_empty(lru))
return NULL;
do {
eb = list_entry(cur, struct extent_buffer, lru);
if (eb->start == start && eb->len == len) {
extent_buffer_get(eb);
return eb;
}
cur = cur->next;
} while (cur != lru);
return NULL;
}
static inline unsigned long num_extent_pages(u64 start, u64 len)
{
return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
(start >> PAGE_CACHE_SHIFT);
}
static inline struct page *extent_buffer_page(struct extent_buffer *eb,
unsigned long i)
{
struct page *p;
struct address_space *mapping;
if (i == 0)
return eb->first_page;
i += eb->start >> PAGE_CACHE_SHIFT;
mapping = eb->first_page->mapping;
read_lock_irq(&mapping->tree_lock);
p = radix_tree_lookup(&mapping->page_tree, i);
read_unlock_irq(&mapping->tree_lock);
return p;
}
int release_extent_buffer_tail_pages(struct extent_buffer *eb)
{
unsigned long num_pages = num_extent_pages(eb->start, eb->len);
struct page *page;
unsigned long i;
if (num_pages == 1)
return 0;
for (i = 1; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
page_cache_release(page);
}
return 0;
}
int invalidate_extent_lru(struct extent_io_tree *tree, u64 start,
unsigned long len)
{
struct list_head *lru = &tree->buffer_lru;
struct list_head *cur = lru->next;
struct extent_buffer *eb;
int found = 0;
spin_lock(&tree->lru_lock);
if (list_empty(lru))
goto out;
do {
eb = list_entry(cur, struct extent_buffer, lru);
if (eb->start <= start && eb->start + eb->len > start) {
eb->flags &= ~EXTENT_UPTODATE;
}
cur = cur->next;
} while (cur != lru);
out:
spin_unlock(&tree->lru_lock);
return found;
}
static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
u64 start,
unsigned long len,
gfp_t mask)
{
struct extent_buffer *eb = NULL;
unsigned long flags;
spin_lock(&tree->lru_lock);
eb = find_lru(tree, start, len);
spin_unlock(&tree->lru_lock);
if (eb) {
return eb;
}
eb = kmem_cache_zalloc(extent_buffer_cache, mask);
INIT_LIST_HEAD(&eb->lru);
eb->start = start;
eb->len = len;
spin_lock_irqsave(&leak_lock, flags);
list_add(&eb->leak_list, &buffers);
spin_unlock_irqrestore(&leak_lock, flags);
atomic_set(&eb->refs, 1);
return eb;
}
static void __free_extent_buffer(struct extent_buffer *eb)
{
unsigned long flags;
spin_lock_irqsave(&leak_lock, flags);
list_del(&eb->leak_list);
spin_unlock_irqrestore(&leak_lock, flags);
kmem_cache_free(extent_buffer_cache, eb);
}
struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
u64 start, unsigned long len,
struct page *page0,
gfp_t mask)
{
unsigned long num_pages = num_extent_pages(start, len);
unsigned long i;
unsigned long index = start >> PAGE_CACHE_SHIFT;
struct extent_buffer *eb;
struct page *p;
struct address_space *mapping = tree->mapping;
int uptodate = 1;
eb = __alloc_extent_buffer(tree, start, len, mask);
if (!eb)
return NULL;
if (eb->flags & EXTENT_BUFFER_FILLED)
goto lru_add;
if (page0) {
eb->first_page = page0;
i = 1;
index++;
page_cache_get(page0);
mark_page_accessed(page0);
set_page_extent_mapped(page0);
set_page_extent_head(page0, len);
uptodate = PageUptodate(page0);
} else {
i = 0;
}
for (; i < num_pages; i++, index++) {
p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
if (!p) {
WARN_ON(1);
goto fail;
}
set_page_extent_mapped(p);
mark_page_accessed(p);
if (i == 0) {
eb->first_page = p;
set_page_extent_head(p, len);
} else {
set_page_private(p, EXTENT_PAGE_PRIVATE);
}
if (!PageUptodate(p))
uptodate = 0;
unlock_page(p);
}
if (uptodate)
eb->flags |= EXTENT_UPTODATE;
eb->flags |= EXTENT_BUFFER_FILLED;
lru_add:
spin_lock(&tree->lru_lock);
add_lru(tree, eb);
spin_unlock(&tree->lru_lock);
return eb;
fail:
spin_lock(&tree->lru_lock);
list_del_init(&eb->lru);
spin_unlock(&tree->lru_lock);
if (!atomic_dec_and_test(&eb->refs))
return NULL;
for (index = 1; index < i; index++) {
page_cache_release(extent_buffer_page(eb, index));
}
if (i > 0)
page_cache_release(extent_buffer_page(eb, 0));
__free_extent_buffer(eb);
return NULL;
}
EXPORT_SYMBOL(alloc_extent_buffer);
struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
u64 start, unsigned long len,
gfp_t mask)
{
unsigned long num_pages = num_extent_pages(start, len);
unsigned long i;
unsigned long index = start >> PAGE_CACHE_SHIFT;
struct extent_buffer *eb;
struct page *p;
struct address_space *mapping = tree->mapping;
int uptodate = 1;
eb = __alloc_extent_buffer(tree, start, len, mask);
if (!eb)
return NULL;
if (eb->flags & EXTENT_BUFFER_FILLED)
goto lru_add;
for (i = 0; i < num_pages; i++, index++) {
p = find_get_page(mapping, index);
if (!p) {
goto fail;
}
if (TestSetPageLocked(p)) {
page_cache_release(p);
goto fail;
}
set_page_extent_mapped(p);
mark_page_accessed(p);
if (i == 0) {
eb->first_page = p;
set_page_extent_head(p, len);
} else {
set_page_private(p, EXTENT_PAGE_PRIVATE);
}
if (!PageUptodate(p))
uptodate = 0;
unlock_page(p);
}
if (uptodate)
eb->flags |= EXTENT_UPTODATE;
eb->flags |= EXTENT_BUFFER_FILLED;
lru_add:
spin_lock(&tree->lru_lock);
add_lru(tree, eb);
spin_unlock(&tree->lru_lock);
return eb;
fail:
spin_lock(&tree->lru_lock);
list_del_init(&eb->lru);
spin_unlock(&tree->lru_lock);
if (!atomic_dec_and_test(&eb->refs))
return NULL;
for (index = 1; index < i; index++) {
page_cache_release(extent_buffer_page(eb, index));
}
if (i > 0)
page_cache_release(extent_buffer_page(eb, 0));
__free_extent_buffer(eb);
return NULL;
}
EXPORT_SYMBOL(find_extent_buffer);
void free_extent_buffer(struct extent_buffer *eb)
{
unsigned long i;
unsigned long num_pages;
if (!eb)
return;
if (!atomic_dec_and_test(&eb->refs))
return;
WARN_ON(!list_empty(&eb->lru));
num_pages = num_extent_pages(eb->start, eb->len);
for (i = 1; i < num_pages; i++) {
page_cache_release(extent_buffer_page(eb, i));
}
page_cache_release(extent_buffer_page(eb, 0));
__free_extent_buffer(eb);
}
EXPORT_SYMBOL(free_extent_buffer);
int clear_extent_buffer_dirty(struct extent_io_tree *tree,
struct extent_buffer *eb)
{
int set;
unsigned long i;
unsigned long num_pages;
struct page *page;
u64 start = eb->start;
u64 end = start + eb->len - 1;
set = clear_extent_dirty(tree, start, end, GFP_NOFS);
num_pages = num_extent_pages(eb->start, eb->len);
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if (i == 0)
set_page_extent_head(page, eb->len);
else
set_page_private(page, EXTENT_PAGE_PRIVATE);
/*
* if we're on the last page or the first page and the
* block isn't aligned on a page boundary, do extra checks
* to make sure we don't clean page that is partially dirty
*/
if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
((i == num_pages - 1) &&
((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
start = (u64)page->index << PAGE_CACHE_SHIFT;
end = start + PAGE_CACHE_SIZE - 1;
if (test_range_bit(tree, start, end,
EXTENT_DIRTY, 0)) {
continue;
}
}
clear_page_dirty_for_io(page);
read_lock_irq(&page->mapping->tree_lock);
if (!PageDirty(page)) {
radix_tree_tag_clear(&page->mapping->page_tree,
page_index(page),
PAGECACHE_TAG_DIRTY);
}
read_unlock_irq(&page->mapping->tree_lock);
}
return 0;
}
EXPORT_SYMBOL(clear_extent_buffer_dirty);
int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
struct extent_buffer *eb)
{
return wait_on_extent_writeback(tree, eb->start,
eb->start + eb->len - 1);
}
EXPORT_SYMBOL(wait_on_extent_buffer_writeback);
int set_extent_buffer_dirty(struct extent_io_tree *tree,
struct extent_buffer *eb)
{
unsigned long i;
unsigned long num_pages;
num_pages = num_extent_pages(eb->start, eb->len);
for (i = 0; i < num_pages; i++) {
struct page *page = extent_buffer_page(eb, i);
/* writepage may need to do something special for the
* first page, we have to make sure page->private is
* properly set. releasepage may drop page->private
* on us if the page isn't already dirty.
*/
if (i == 0) {
set_page_extent_head(page, eb->len);
} else if (PagePrivate(page) &&
page->private != EXTENT_PAGE_PRIVATE) {
set_page_extent_mapped(page);
}
__set_page_dirty_nobuffers(extent_buffer_page(eb, i));
}
return set_extent_dirty(tree, eb->start,
eb->start + eb->len - 1, GFP_NOFS);
}
EXPORT_SYMBOL(set_extent_buffer_dirty);
int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
struct extent_buffer *eb)
{
unsigned long i;
struct page *page;
unsigned long num_pages;
num_pages = num_extent_pages(eb->start, eb->len);
eb->flags &= ~EXTENT_UPTODATE;
clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
GFP_NOFS);
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
ClearPageUptodate(page);
}
return 0;
}
int set_extent_buffer_uptodate(struct extent_io_tree *tree,
struct extent_buffer *eb)
{
unsigned long i;
struct page *page;
unsigned long num_pages;
num_pages = num_extent_pages(eb->start, eb->len);
set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
GFP_NOFS);
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
((i == num_pages - 1) &&
((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
check_page_uptodate(tree, page);
continue;
}
SetPageUptodate(page);
}
return 0;
}
EXPORT_SYMBOL(set_extent_buffer_uptodate);
int extent_range_uptodate(struct extent_io_tree *tree,
u64 start, u64 end)
{
struct page *page;
int ret;
int pg_uptodate = 1;
int uptodate;
unsigned long index;
ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1);
if (ret)
return 1;
while(start <= end) {
index = start >> PAGE_CACHE_SHIFT;
page = find_get_page(tree->mapping, index);
uptodate = PageUptodate(page);
page_cache_release(page);
if (!uptodate) {
pg_uptodate = 0;
break;
}
start += PAGE_CACHE_SIZE;
}
return pg_uptodate;
}
int extent_buffer_uptodate(struct extent_io_tree *tree,
struct extent_buffer *eb)
{
int ret = 0;
unsigned long num_pages;
unsigned long i;
struct page *page;
int pg_uptodate = 1;
if (eb->flags & EXTENT_UPTODATE)
return 1;
ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
EXTENT_UPTODATE, 1);
if (ret)
return ret;
num_pages = num_extent_pages(eb->start, eb->len);
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if (!PageUptodate(page)) {
pg_uptodate = 0;
break;
}
}
return pg_uptodate;
}
EXPORT_SYMBOL(extent_buffer_uptodate);
int read_extent_buffer_pages(struct extent_io_tree *tree,
struct extent_buffer *eb,
u64 start, int wait,
get_extent_t *get_extent, int mirror_num)
{
unsigned long i;
unsigned long start_i;
struct page *page;
int err;
int ret = 0;
int locked_pages = 0;
int all_uptodate = 1;
int inc_all_pages = 0;
unsigned long num_pages;
struct bio *bio = NULL;
if (eb->flags & EXTENT_UPTODATE)
return 0;
if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
EXTENT_UPTODATE, 1)) {
return 0;
}
if (start) {
WARN_ON(start < eb->start);
start_i = (start >> PAGE_CACHE_SHIFT) -
(eb->start >> PAGE_CACHE_SHIFT);
} else {
start_i = 0;
}
num_pages = num_extent_pages(eb->start, eb->len);
for (i = start_i; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if (!wait) {
if (TestSetPageLocked(page))
goto unlock_exit;
} else {
lock_page(page);
}
locked_pages++;
if (!PageUptodate(page)) {
all_uptodate = 0;
}
}
if (all_uptodate) {
if (start_i == 0)
eb->flags |= EXTENT_UPTODATE;
goto unlock_exit;
}
for (i = start_i; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if (inc_all_pages)
page_cache_get(page);
if (!PageUptodate(page)) {
if (start_i == 0)
inc_all_pages = 1;
ClearPageError(page);
err = __extent_read_full_page(tree, page,
get_extent, &bio,
mirror_num);
if (err) {
ret = err;
}
} else {
unlock_page(page);
}
}
if (bio)
submit_one_bio(READ, bio, mirror_num);
if (ret || !wait) {
return ret;
}
for (i = start_i; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
wait_on_page_locked(page);
if (!PageUptodate(page)) {
ret = -EIO;
}
}
if (!ret)
eb->flags |= EXTENT_UPTODATE;
return ret;
unlock_exit:
i = start_i;
while(locked_pages > 0) {
page = extent_buffer_page(eb, i);
i++;
unlock_page(page);
locked_pages--;
}
return ret;
}
EXPORT_SYMBOL(read_extent_buffer_pages);
void read_extent_buffer(struct extent_buffer *eb, void *dstv,
unsigned long start,
unsigned long len)
{
size_t cur;
size_t offset;
struct page *page;
char *kaddr;
char *dst = (char *)dstv;
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
WARN_ON(start > eb->len);
WARN_ON(start + len > eb->start + eb->len);
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
while(len > 0) {
page = extent_buffer_page(eb, i);
cur = min(len, (PAGE_CACHE_SIZE - offset));
kaddr = kmap_atomic(page, KM_USER1);
memcpy(dst, kaddr + offset, cur);
kunmap_atomic(kaddr, KM_USER1);
dst += cur;
len -= cur;
offset = 0;
i++;
}
}
EXPORT_SYMBOL(read_extent_buffer);
int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
unsigned long min_len, char **token, char **map,
unsigned long *map_start,
unsigned long *map_len, int km)
{
size_t offset = start & (PAGE_CACHE_SIZE - 1);
char *kaddr;
struct page *p;
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
unsigned long end_i = (start_offset + start + min_len - 1) >>
PAGE_CACHE_SHIFT;
if (i != end_i)
return -EINVAL;
if (i == 0) {
offset = start_offset;
*map_start = 0;
} else {
offset = 0;
*map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
}
if (start + min_len > eb->len) {
printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len);
WARN_ON(1);
}
p = extent_buffer_page(eb, i);
kaddr = kmap_atomic(p, km);
*token = kaddr;
*map = kaddr + offset;
*map_len = PAGE_CACHE_SIZE - offset;
return 0;
}
EXPORT_SYMBOL(map_private_extent_buffer);
int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
unsigned long min_len,
char **token, char **map,
unsigned long *map_start,
unsigned long *map_len, int km)
{
int err;
int save = 0;
if (eb->map_token) {
unmap_extent_buffer(eb, eb->map_token, km);
eb->map_token = NULL;
save = 1;
}
err = map_private_extent_buffer(eb, start, min_len, token, map,
map_start, map_len, km);
if (!err && save) {
eb->map_token = *token;
eb->kaddr = *map;
eb->map_start = *map_start;
eb->map_len = *map_len;
}
return err;
}
EXPORT_SYMBOL(map_extent_buffer);
void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
{
kunmap_atomic(token, km);
}
EXPORT_SYMBOL(unmap_extent_buffer);
int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
unsigned long start,
unsigned long len)
{
size_t cur;
size_t offset;
struct page *page;
char *kaddr;
char *ptr = (char *)ptrv;
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
int ret = 0;
WARN_ON(start > eb->len);
WARN_ON(start + len > eb->start + eb->len);
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
while(len > 0) {
page = extent_buffer_page(eb, i);
cur = min(len, (PAGE_CACHE_SIZE - offset));
kaddr = kmap_atomic(page, KM_USER0);
ret = memcmp(ptr, kaddr + offset, cur);
kunmap_atomic(kaddr, KM_USER0);
if (ret)
break;
ptr += cur;
len -= cur;
offset = 0;
i++;
}
return ret;
}
EXPORT_SYMBOL(memcmp_extent_buffer);
void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
unsigned long start, unsigned long len)
{
size_t cur;
size_t offset;
struct page *page;
char *kaddr;
char *src = (char *)srcv;
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
WARN_ON(start > eb->len);
WARN_ON(start + len > eb->start + eb->len);
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
while(len > 0) {
page = extent_buffer_page(eb, i);
WARN_ON(!PageUptodate(page));
cur = min(len, PAGE_CACHE_SIZE - offset);
kaddr = kmap_atomic(page, KM_USER1);
memcpy(kaddr + offset, src, cur);
kunmap_atomic(kaddr, KM_USER1);
src += cur;
len -= cur;
offset = 0;
i++;
}
}
EXPORT_SYMBOL(write_extent_buffer);
void memset_extent_buffer(struct extent_buffer *eb, char c,
unsigned long start, unsigned long len)
{
size_t cur;
size_t offset;
struct page *page;
char *kaddr;
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
WARN_ON(start > eb->len);
WARN_ON(start + len > eb->start + eb->len);
offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
while(len > 0) {
page = extent_buffer_page(eb, i);
WARN_ON(!PageUptodate(page));
cur = min(len, PAGE_CACHE_SIZE - offset);
kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr + offset, c, cur);
kunmap_atomic(kaddr, KM_USER0);
len -= cur;
offset = 0;
i++;
}
}
EXPORT_SYMBOL(memset_extent_buffer);
void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
unsigned long dst_offset, unsigned long src_offset,
unsigned long len)
{
u64 dst_len = dst->len;
size_t cur;
size_t offset;
struct page *page;
char *kaddr;
size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
WARN_ON(src->len != dst_len);
offset = (start_offset + dst_offset) &
((unsigned long)PAGE_CACHE_SIZE - 1);
while(len > 0) {
page = extent_buffer_page(dst, i);
WARN_ON(!PageUptodate(page));
cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
kaddr = kmap_atomic(page, KM_USER0);
read_extent_buffer(src, kaddr + offset, src_offset, cur);
kunmap_atomic(kaddr, KM_USER0);
src_offset += cur;
len -= cur;
offset = 0;
i++;
}
}
EXPORT_SYMBOL(copy_extent_buffer);
static void move_pages(struct page *dst_page, struct page *src_page,
unsigned long dst_off, unsigned long src_off,
unsigned long len)
{
char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
if (dst_page == src_page) {
memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
} else {
char *src_kaddr = kmap_atomic(src_page, KM_USER1);
char *p = dst_kaddr + dst_off + len;
char *s = src_kaddr + src_off + len;
while (len--)
*--p = *--s;
kunmap_atomic(src_kaddr, KM_USER1);
}
kunmap_atomic(dst_kaddr, KM_USER0);
}
static void copy_pages(struct page *dst_page, struct page *src_page,
unsigned long dst_off, unsigned long src_off,
unsigned long len)
{
char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
char *src_kaddr;
if (dst_page != src_page)
src_kaddr = kmap_atomic(src_page, KM_USER1);
else
src_kaddr = dst_kaddr;
memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
kunmap_atomic(dst_kaddr, KM_USER0);
if (dst_page != src_page)
kunmap_atomic(src_kaddr, KM_USER1);
}
void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
unsigned long src_offset, unsigned long len)
{
size_t cur;
size_t dst_off_in_page;
size_t src_off_in_page;
size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
unsigned long dst_i;
unsigned long src_i;
if (src_offset + len > dst->len) {
printk("memmove bogus src_offset %lu move len %lu len %lu\n",
src_offset, len, dst->len);
BUG_ON(1);
}
if (dst_offset + len > dst->len) {
printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
dst_offset, len, dst->len);
BUG_ON(1);
}
while(len > 0) {
dst_off_in_page = (start_offset + dst_offset) &
((unsigned long)PAGE_CACHE_SIZE - 1);
src_off_in_page = (start_offset + src_offset) &
((unsigned long)PAGE_CACHE_SIZE - 1);
dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
src_off_in_page));
cur = min_t(unsigned long, cur,
(unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
copy_pages(extent_buffer_page(dst, dst_i),
extent_buffer_page(dst, src_i),
dst_off_in_page, src_off_in_page, cur);
src_offset += cur;
dst_offset += cur;
len -= cur;
}
}
EXPORT_SYMBOL(memcpy_extent_buffer);
void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
unsigned long src_offset, unsigned long len)
{
size_t cur;
size_t dst_off_in_page;
size_t src_off_in_page;
unsigned long dst_end = dst_offset + len - 1;
unsigned long src_end = src_offset + len - 1;
size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
unsigned long dst_i;
unsigned long src_i;
if (src_offset + len > dst->len) {
printk("memmove bogus src_offset %lu move len %lu len %lu\n",
src_offset, len, dst->len);
BUG_ON(1);
}
if (dst_offset + len > dst->len) {
printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
dst_offset, len, dst->len);
BUG_ON(1);
}
if (dst_offset < src_offset) {
memcpy_extent_buffer(dst, dst_offset, src_offset, len);
return;
}
while(len > 0) {
dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
dst_off_in_page = (start_offset + dst_end) &
((unsigned long)PAGE_CACHE_SIZE - 1);
src_off_in_page = (start_offset + src_end) &
((unsigned long)PAGE_CACHE_SIZE - 1);
cur = min_t(unsigned long, len, src_off_in_page + 1);
cur = min(cur, dst_off_in_page + 1);
move_pages(extent_buffer_page(dst, dst_i),
extent_buffer_page(dst, src_i),
dst_off_in_page - cur + 1,
src_off_in_page - cur + 1, cur);
dst_end -= cur;
src_end -= cur;
len -= cur;
}
}
EXPORT_SYMBOL(memmove_extent_buffer);
