#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 "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_map_cache;
static struct kmem_cache *extent_state_cache;
static struct kmem_cache *extent_buffer_cache;
static LIST_HEAD(extent_buffers);
static LIST_HEAD(buffers);
static LIST_HEAD(states);
static spinlock_t extent_buffers_lock;
static spinlock_t state_lock = SPIN_LOCK_UNLOCKED;
static int nr_extent_buffers;
#define MAX_EXTENT_BUFFER_CACHE 128
struct tree_entry {
u64 start;
u64 end;
int in_tree;
struct rb_node rb_node;
};
void __init extent_map_init(void)
{
extent_map_cache = btrfs_cache_create("extent_map",
sizeof(struct extent_map), 0,
NULL);
extent_state_cache = btrfs_cache_create("extent_state",
sizeof(struct extent_state), 0,
NULL);
extent_buffer_cache = btrfs_cache_create("extent_buffers",
sizeof(struct extent_buffer), 0,
NULL);
spin_lock_init(&extent_buffers_lock);
}
void __exit extent_map_exit(void)
{
struct extent_buffer *eb;
struct extent_state *state;
while (!list_empty(&extent_buffers)) {
eb = list_entry(extent_buffers.next,
struct extent_buffer, list);
list_del(&eb->list);
kmem_cache_free(extent_buffer_cache, eb);
}
while (!list_empty(&states)) {
state = list_entry(states.next, struct extent_state, list);
printk("state leak: start %Lu end %Lu state %lu in tree %d refs %d\n", state->start, state->end, state->state, state->in_tree, atomic_read(&state->refs));
list_del(&state->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 return %lX\n", eb->start, eb->len, eb->alloc_addr);
list_del(&eb->leak_list);
kmem_cache_free(extent_buffer_cache, eb);
}
if (extent_map_cache)
kmem_cache_destroy(extent_map_cache);
if (extent_state_cache)
kmem_cache_destroy(extent_state_cache);
if (extent_buffer_cache)
kmem_cache_destroy(extent_buffer_cache);
}
void extent_map_tree_init(struct extent_map_tree *tree,
struct address_space *mapping, gfp_t mask)
{
tree->map.rb_node = NULL;
tree->state.rb_node = NULL;
tree->ops = NULL;
rwlock_init(&tree->lock);
tree->mapping = mapping;
}
EXPORT_SYMBOL(extent_map_tree_init);
struct extent_map *alloc_extent_map(gfp_t mask)
{
struct extent_map *em;
em = kmem_cache_alloc(extent_map_cache, mask);
if (!em || IS_ERR(em))
return em;
em->in_tree = 0;
atomic_set(&em->refs, 1);
return em;
}
EXPORT_SYMBOL(alloc_extent_map);
void free_extent_map(struct extent_map *em)
{
if (!em)
return;
if (atomic_dec_and_test(&em->refs)) {
WARN_ON(em->in_tree);
kmem_cache_free(extent_map_cache, em);
}
}
EXPORT_SYMBOL(free_extent_map);
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 || IS_ERR(state))
return state;
state->state = 0;
state->in_tree = 0;
state->private = 0;
spin_lock_irqsave(&state_lock, flags);
list_add(&state->list, &states);
spin_unlock_irqrestore(&state_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)
{
unsigned long flags;
if (!state)
return;
if (atomic_dec_and_test(&state->refs)) {
WARN_ON(state->in_tree);
spin_lock_irqsave(&state_lock, flags);
list_del(&state->list);
spin_unlock_irqrestore(&state_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);
entry->in_tree = 1;
rb_link_node(node, parent, p);
rb_insert_color(node, root);
return NULL;
}
static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
struct rb_node **prev_ret)
{
struct rb_node * n = root->rb_node;
struct rb_node *prev = NULL;
struct tree_entry *entry;
struct tree_entry *prev_entry = NULL;
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
return n;
}
if (!prev_ret)
return NULL;
while(prev && offset > prev_entry->end) {
prev = rb_next(prev);
prev_entry = rb_entry(prev, struct tree_entry, rb_node);
}
*prev_ret = prev;
return NULL;
}
static inline struct rb_node *tree_search(struct rb_root *root, u64 offset)
{
struct rb_node *prev;
struct rb_node *ret;
ret = __tree_search(root, offset, &prev);
if (!ret)
return prev;
return ret;
}
static int tree_delete(struct rb_root *root, u64 offset)
{
struct rb_node *node;
struct tree_entry *entry;
node = __tree_search(root, offset, NULL);
if (!node)
return -ENOENT;
entry = rb_entry(node, struct tree_entry, rb_node);
entry->in_tree = 0;
rb_erase(node, root);
return 0;
}
/*
* add_extent_mapping tries a simple backward merge with existing
* mappings. The extent_map struct passed in will be inserted into
* the tree directly (no copies made, just a reference taken).
*/
int add_extent_mapping(struct extent_map_tree *tree,
struct extent_map *em)
{
int ret = 0;
struct extent_map *prev = NULL;
struct rb_node *rb;
write_lock_irq(&tree->lock);
rb = tree_insert(&tree->map, em->end, &em->rb_node);
if (rb) {
prev = rb_entry(rb, struct extent_map, rb_node);
printk("found extent map %Lu %Lu on insert of %Lu %Lu\n", prev->start, prev->end, em->start, em->end);
ret = -EEXIST;
goto out;
}
atomic_inc(&em->refs);
if (em->start != 0) {
rb = rb_prev(&em->rb_node);
if (rb)
prev = rb_entry(rb, struct extent_map, rb_node);
if (prev && prev->end + 1 == em->start &&
((em->block_start == EXTENT_MAP_HOLE &&
prev->block_start == EXTENT_MAP_HOLE) ||
(em->block_start == prev->block_end + 1))) {
em->start = prev->start;
em->block_start = prev->block_start;
rb_erase(&prev->rb_node, &tree->map);
prev->in_tree = 0;
free_extent_map(prev);
}
}
out:
write_unlock_irq(&tree->lock);
return ret;
}
EXPORT_SYMBOL(add_extent_mapping);
/*
* lookup_extent_mapping returns the first extent_map struct in the
* tree that intersects the [start, end] (inclusive) range. There may
* be additional objects in the tree that intersect, so check the object
* returned carefully to make sure you don't need additional lookups.
*/
struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
u64 start, u64 end)
{
struct extent_map *em;
struct rb_node *rb_node;
read_lock_irq(&tree->lock);
rb_node = tree_search(&tree->map, start);
if (!rb_node) {
em = NULL;
goto out;
}
if (IS_ERR(rb_node)) {
em = ERR_PTR(PTR_ERR(rb_node));
goto out;
}
em = rb_entry(rb_node, struct extent_map, rb_node);
if (em->end < start || em->start > end) {
em = NULL;
goto out;
}
atomic_inc(&em->refs);
out:
read_unlock_irq(&tree->lock);
return em;
}
EXPORT_SYMBOL(lookup_extent_mapping);
/*
* removes an extent_map struct from the tree. No reference counts are
* dropped, and no checks are done to see if the range is in use
*/
int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
{
int ret;
write_lock_irq(&tree->lock);
ret = tree_delete(&tree->map, em->end);
write_unlock_irq(&tree->lock);
return ret;
}
EXPORT_SYMBOL(remove_extent_mapping);
/*
* 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_map_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->in_tree = 0;
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->in_tree = 0;
rb_erase(&state->rb_node, &tree->state);
free_extent_state(state);
}
}
return 0;
}
/*
* 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_map_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);
}
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;
}
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_map_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;
}
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_map_tree *tree,
struct extent_state *state, int bits, int wake,
int delete)
{
int ret = state->state & bits;
state->state &= ~bits;
if (wake)
wake_up(&state->wq);
if (delete || state->state == 0) {
if (state->in_tree) {
rb_erase(&state->rb_node, &tree->state);
state->in_tree = 0;
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_map_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;
}
write_lock_irqsave(&tree->lock, flags);
/*
* this search will find the extents that end after
* our range starts
*/
node = tree_search(&tree->state, 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) {
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) {
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:
write_unlock_irqrestore(&tree->lock, flags);
if (prealloc)
free_extent_state(prealloc);
return set;
search_again:
if (start > end)
goto out;
write_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_map_tree *tree,
struct extent_state *state)
{
DEFINE_WAIT(wait);
prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
read_unlock_irq(&tree->lock);
schedule();
read_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_map_tree *tree, u64 start, u64 end, int bits)
{
struct extent_state *state;
struct rb_node *node;
read_lock_irq(&tree->lock);
again:
while (1) {
/*
* this search will find all the extents that end after
* our range starts
*/
node = tree_search(&tree->state, 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()) {
read_unlock_irq(&tree->lock);
cond_resched();
read_lock_irq(&tree->lock);
}
}
out:
read_unlock_irq(&tree->lock);
return 0;
}
EXPORT_SYMBOL(wait_extent_bit);
/*
* 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_map_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;
}
write_lock_irqsave(&tree->lock, flags);
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(&tree->state, 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;
}
state->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) {
state->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);
prealloc->state |= bits;
merge_state(tree, prealloc);
prealloc = NULL;
goto out;
}
goto search_again;
out:
write_unlock_irqrestore(&tree->lock, flags);
if (prealloc)
free_extent_state(prealloc);
return err;
search_again:
if (start > end)
goto out;
write_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_map_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_bits(struct extent_map_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_map_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_map_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_map_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 set_extent_new(struct extent_map_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_map_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_map_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_map_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_map_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_map_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_map_tree *tree, u64 start, u64 end)
{
return wait_extent_bit(tree, start, end, EXTENT_WRITEBACK);
}
EXPORT_SYMBOL(wait_on_extent_writeback);
/*
* locks a range in ascending order, waiting for any locked regions
* it hits on the way. [start,end] are inclusive, and this will sleep.
*/
int lock_extent(struct extent_map_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_map_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_map_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_map_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_map_tree *tree, u64 start,
u64 *start_ret, u64 *end_ret, int bits)
{
struct rb_node *node;
struct extent_state *state;
int ret = 1;
write_lock_irq(&tree->lock);
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(&tree->state, start);
if (!node || IS_ERR(node)) {
goto out;
}
while(1) {
state = rb_entry(node, struct extent_state, rb_node);
if (state->state & bits) {
*start_ret = state->start;
*end_ret = state->end;
ret = 0;
break;
}
node = rb_next(node);
if (!node)
break;
}
out:
write_unlock_irq(&tree->lock);
return ret;
}
EXPORT_SYMBOL(find_first_extent_bit);
u64 find_lock_delalloc_range(struct extent_map_tree *tree,
u64 start, u64 lock_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;
write_lock_irq(&tree->lock);
/*
* this search will find all the extents that end after
* our range starts.
*/
search_again:
node = tree_search(&tree->state, cur_start);
if (!node || IS_ERR(node)) {
goto out;
}
while(1) {
state = rb_entry(node, struct extent_state, rb_node);
if (state->start != cur_start) {
goto out;
}
if (!(state->state & EXTENT_DELALLOC)) {
goto out;
}
if (state->start >= lock_start) {
if (state->state & EXTENT_LOCKED) {
DEFINE_WAIT(wait);
atomic_inc(&state->refs);
write_unlock_irq(&tree->lock);
schedule();
write_lock_irq(&tree->lock);
finish_wait(&state->wq, &wait);
free_extent_state(state);
goto search_again;
}
state->state |= EXTENT_LOCKED;
}
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:
write_unlock_irq(&tree->lock);
return found;
}
/*
* helper function to lock both pages and extents in the tree.
* pages must be locked first.
*/
int lock_range(struct extent_map_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_map_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_map_tree *tree, u64 start, u64 private)
{
struct rb_node *node;
struct extent_state *state;
int ret = 0;
write_lock_irq(&tree->lock);
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(&tree->state, start);
if (!node || IS_ERR(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:
write_unlock_irq(&tree->lock);
return ret;
}
int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private)
{
struct rb_node *node;
struct extent_state *state;
int ret = 0;
read_lock_irq(&tree->lock);
/*
* this search will find all the extents that end after
* our range starts.
*/
node = tree_search(&tree->state, start);
if (!node || IS_ERR(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:
read_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 ever 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_map_tree *tree, u64 start, u64 end,
int bits, int filled)
{
struct extent_state *state = NULL;
struct rb_node *node;
int bitset = 0;
read_lock_irq(&tree->lock);
node = tree_search(&tree->state, start);
while (node && start <= end) {
state = rb_entry(node, struct extent_state, rb_node);
if (state->start > end)
break;
if (filled && state->start > start) {
bitset = 0;
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);
}
read_unlock_irq(&tree->lock);
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_map_tree *tree,
struct page *page)
{
u64 start = 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_map_tree *tree,
struct page *page)
{
u64 start = 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_map_tree *tree,
struct page *page)
{
u64 start = 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.
*/
static int end_bio_extent_writepage(struct bio *bio,
unsigned int bytes_done, int err)
{
const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
struct extent_map_tree *tree = bio->bi_private;
u64 start;
u64 end;
int whole_page;
if (bio->bi_size)
return 1;
do {
struct page *page = bvec->bv_page;
start = (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) {
clear_extent_uptodate(tree, start, end, GFP_ATOMIC);
ClearPageUptodate(page);
SetPageError(page);
}
clear_extent_writeback(tree, start, end, GFP_ATOMIC);
if (whole_page)
end_page_writeback(page);
else
check_page_writeback(tree, page);
if (tree->ops && tree->ops->writepage_end_io_hook)
tree->ops->writepage_end_io_hook(page, start, end);
} while (bvec >= bio->bi_io_vec);
bio_put(bio);
return 0;
}
/*
* 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.
*/
static int end_bio_extent_readpage(struct bio *bio,
unsigned int bytes_done, int err)
{
int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
struct extent_map_tree *tree = bio->bi_private;
u64 start;
u64 end;
int whole_page;
int ret;
if (bio->bi_size)
return 1;
do {
struct page *page = bvec->bv_page;
start = (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);
if (ret)
uptodate = 0;
}
if (uptodate) {
set_extent_uptodate(tree, start, end, GFP_ATOMIC);
if (whole_page)
SetPageUptodate(page);
else
check_page_uptodate(tree, page);
} else {
ClearPageUptodate(page);
SetPageError(page);
}
unlock_extent(tree, start, end, GFP_ATOMIC);
if (whole_page)
unlock_page(page);
else
check_page_locked(tree, page);
} while (bvec >= bio->bi_io_vec);
bio_put(bio);
return 0;
}
/*
* 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.
*/
static int end_bio_extent_preparewrite(struct bio *bio,
unsigned int bytes_done, int err)
{
const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
struct extent_map_tree *tree = bio->bi_private;
u64 start;
u64 end;
if (bio->bi_size)
return 1;
do {
struct page *page = bvec->bv_page;
start = (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);
return 0;
}
static int submit_extent_page(int rw, struct extent_map_tree *tree,
struct page *page, sector_t sector,
size_t size, unsigned long offset,
struct block_device *bdev,
bio_end_io_t end_io_func)
{
struct bio *bio;
int ret = 0;
bio = bio_alloc(GFP_NOIO, 1);
bio->bi_sector = sector;
bio->bi_bdev = bdev;
bio->bi_io_vec[0].bv_page = page;
bio->bi_io_vec[0].bv_len = size;
bio->bi_io_vec[0].bv_offset = offset;
bio->bi_vcnt = 1;
bio->bi_idx = 0;
bio->bi_size = size;
bio->bi_end_io = end_io_func;
bio->bi_private = tree;
bio_get(bio);
submit_bio(rw, bio);
if (bio_flagged(bio, BIO_EOPNOTSUPP))
ret = -EOPNOTSUPP;
bio_put(bio);
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, 1);
page_cache_get(page);
}
}
/*
* 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)
*/
int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
get_extent_t *get_extent)
{
struct inode *inode = page->mapping->host;
u64 start = 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) {
iosize = PAGE_CACHE_SIZE - page_offset;
zero_user_page(page, page_offset, iosize, 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, 0);
if (IS_ERR(em) || !em) {
SetPageError(page);
unlock_extent(tree, cur, end, GFP_NOFS);
break;
}
extent_offset = cur - em->start;
BUG_ON(em->end < cur);
BUG_ON(end < cur);
iosize = min(em->end - cur, end - cur) + 1;
cur_end = min(em->end, 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) {
zero_user_page(page, page_offset, iosize, 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;
}
ret = 0;
if (tree->ops && tree->ops->readpage_io_hook) {
ret = tree->ops->readpage_io_hook(page, cur,
cur + iosize - 1);
}
if (!ret) {
ret = submit_extent_page(READ, tree, page,
sector, iosize, page_offset,
bdev, end_bio_extent_readpage);
}
if (ret)
SetPageError(page);
cur = cur + iosize;
page_offset += iosize;
nr++;
}
if (!nr) {
if (!PageError(page))
SetPageUptodate(page);
unlock_page(page);
}
return 0;
}
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
*/
int extent_write_full_page(struct extent_map_tree *tree, struct page *page,
get_extent_t *get_extent,
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
u64 start = 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;
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;
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));
if (page->index > end_index) {
clear_extent_dirty(tree, start, page_end, GFP_NOFS);
unlock_page(page);
return 0;
}
if (page->index == end_index) {
size_t offset = i_size & (PAGE_CACHE_SIZE - 1);
zero_user_page(page, offset,
PAGE_CACHE_SIZE - offset, KM_USER0);
}
set_page_extent_mapped(page);
lock_extent(tree, start, page_end, GFP_NOFS);
nr_delalloc = find_lock_delalloc_range(tree, start, page_end + 1,
&delalloc_end,
128 * 1024 * 1024);
if (nr_delalloc) {
tree->ops->fill_delalloc(inode, start, delalloc_end);
if (delalloc_end >= page_end + 1) {
clear_extent_bit(tree, page_end + 1, delalloc_end,
EXTENT_LOCKED | EXTENT_DELALLOC,
1, 0, GFP_NOFS);
}
clear_extent_bit(tree, start, page_end, EXTENT_DELALLOC,
0, 0, GFP_NOFS);
if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
printk("found delalloc bits after clear extent_bit\n");
}
} else if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
printk("found delalloc bits after find_delalloc_range returns 0\n");
}
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);
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);
break;
}
em = get_extent(inode, page, page_offset, cur, end, 0);
if (IS_ERR(em) || !em) {
SetPageError(page);
break;
}
extent_offset = cur - em->start;
BUG_ON(em->end < cur);
BUG_ON(end < cur);
iosize = min(em->end - 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);
cur = cur + iosize;
page_offset += iosize;
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;
page_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 {
set_range_writeback(tree, cur, cur + iosize - 1);
ret = submit_extent_page(WRITE, tree, page, sector,
iosize, page_offset, bdev,
end_bio_extent_writepage);
if (ret)
SetPageError(page);
}
cur = cur + iosize;
page_offset += iosize;
nr++;
}
done:
unlock_extent(tree, start, page_end, GFP_NOFS);
unlock_page(page);
return 0;
}
EXPORT_SYMBOL(extent_write_full_page);
/*
* 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_map_tree *tree,
struct page *page, unsigned long offset)
{
u64 start = (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_map_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_map_tree *tree,
struct inode *inode, struct page *page,
unsigned from, unsigned to, get_extent_t *get_extent)
{
u64 page_start = 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, 1);
if (IS_ERR(em) || !em) {
goto err;
}
cur_end = min(block_end, em->end);
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 (!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 - 1) &
~((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,
end_bio_extent_preparewrite);
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. 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 *tree, struct page *page)
{
struct extent_map *em;
u64 start = page->index << PAGE_CACHE_SHIFT;
u64 end = start + PAGE_CACHE_SIZE - 1;
u64 orig_start = start;
int ret = 1;
while (start <= end) {
em = lookup_extent_mapping(tree, start, end);
if (!em || IS_ERR(em))
break;
if (!test_range_bit(tree, em->start, em->end,
EXTENT_LOCKED, 0)) {
remove_extent_mapping(tree, em);
/* once for the rb tree */
free_extent_map(em);
}
start = em->end + 1;
/* once for us */
free_extent_map(em);
}
if (test_range_bit(tree, orig_start, end, EXTENT_LOCKED, 0))
ret = 0;
else
clear_extent_bit(tree, orig_start, end, EXTENT_UPTODATE,
1, 1, GFP_NOFS);
return ret;
}
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;
u64 end = start + (1 << inode->i_blkbits) - 1;
struct extent_map *em;
em = get_extent(inode, NULL, 0, start, end, 0);
if (!em || IS_ERR(em))
return 0;
if (em->block_start == EXTENT_MAP_INLINE ||
em->block_start == EXTENT_MAP_HOLE)
return 0;
return (em->block_start + start - em->start) >> inode->i_blkbits;
}
static struct extent_buffer *__alloc_extent_buffer(gfp_t mask)
{
struct extent_buffer *eb = NULL;
spin_lock(&extent_buffers_lock);
if (!list_empty(&extent_buffers)) {
eb = list_entry(extent_buffers.next, struct extent_buffer,
list);
list_del(&eb->list);
WARN_ON(nr_extent_buffers == 0);
nr_extent_buffers--;
}
spin_unlock(&extent_buffers_lock);
if (eb) {
memset(eb, 0, sizeof(*eb));
} else {
eb = kmem_cache_zalloc(extent_buffer_cache, mask);
}
spin_lock(&extent_buffers_lock);
list_add(&eb->leak_list, &buffers);
spin_unlock(&extent_buffers_lock);
return eb;
}
static void __free_extent_buffer(struct extent_buffer *eb)
{
spin_lock(&extent_buffers_lock);
list_del_init(&eb->leak_list);
spin_unlock(&extent_buffers_lock);
if (nr_extent_buffers >= MAX_EXTENT_BUFFER_CACHE) {
kmem_cache_free(extent_buffer_cache, eb);
} else {
spin_lock(&extent_buffers_lock);
list_add(&eb->list, &extent_buffers);
nr_extent_buffers++;
spin_unlock(&extent_buffers_lock);
}
}
static inline struct page *extent_buffer_page(struct extent_buffer *eb, int i)
{
struct page *p;
if (i == 0)
return eb->first_page;
i += eb->start >> PAGE_CACHE_SHIFT;
p = find_get_page(eb->first_page->mapping, i);
page_cache_release(p);
return p;
}
struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
u64 start, unsigned long len,
gfp_t mask)
{
unsigned long num_pages = ((start + len - 1) >> PAGE_CACHE_SHIFT) -
(start >> PAGE_CACHE_SHIFT) + 1;
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 = 0;
eb = __alloc_extent_buffer(mask);
if (!eb || IS_ERR(eb))
return NULL;
eb->alloc_addr = __builtin_return_address(0);
eb->start = start;
eb->len = len;
atomic_set(&eb->refs, 1);
for (i = 0; i < num_pages; i++, index++) {
p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
if (!p) {
/* make sure the free only frees the pages we've
* grabbed a reference on
*/
eb->len = i << PAGE_CACHE_SHIFT;
eb->start &= ~((u64)PAGE_CACHE_SIZE - 1);
goto fail;
}
set_page_extent_mapped(p);
if (i == 0)
eb->first_page = p;
if (!PageUptodate(p))
uptodate = 0;
unlock_page(p);
}
if (uptodate)
eb->flags |= EXTENT_UPTODATE;
return eb;
fail:
free_extent_buffer(eb);
return NULL;
}
EXPORT_SYMBOL(alloc_extent_buffer);
struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
u64 start, unsigned long len,
gfp_t mask)
{
unsigned long num_pages = ((start + len - 1) >> PAGE_CACHE_SHIFT) -
(start >> PAGE_CACHE_SHIFT) + 1;
unsigned long i;
unsigned long index = start >> PAGE_CACHE_SHIFT;
struct extent_buffer *eb;
struct page *p;
struct address_space *mapping = tree->mapping;
eb = __alloc_extent_buffer(mask);
if (!eb || IS_ERR(eb))
return NULL;
eb->alloc_addr = __builtin_return_address(0);
eb->start = start;
eb->len = len;
atomic_set(&eb->refs, 1);
for (i = 0; i < num_pages; i++, index++) {
p = find_get_page(mapping, index);
if (!p) {
/* make sure the free only frees the pages we've
* grabbed a reference on
*/
eb->len = i << PAGE_CACHE_SHIFT;
eb->start &= ~((u64)PAGE_CACHE_SIZE - 1);
goto fail;
}
set_page_extent_mapped(p);
if (i == 0)
eb->first_page = p;
}
return eb;
fail:
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;
num_pages = ((eb->start + eb->len - 1) >> PAGE_CACHE_SHIFT) -
(eb->start >> PAGE_CACHE_SHIFT) + 1;
if (eb->first_page)
page_cache_release(eb->first_page);
for (i = 1; i < num_pages; i++) {
page_cache_release(extent_buffer_page(eb, i));
}
__free_extent_buffer(eb);
}
EXPORT_SYMBOL(free_extent_buffer);
int clear_extent_buffer_dirty(struct extent_map_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 = ((eb->start + eb->len - 1) >> PAGE_CACHE_SHIFT) -
(eb->start >> PAGE_CACHE_SHIFT) + 1;
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
lock_page(page);
/*
* 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 - 1) & (PAGE_CACHE_SIZE - 1)))) {
start = page->index << PAGE_CACHE_SHIFT;
end = start + PAGE_CACHE_SIZE - 1;
if (test_range_bit(tree, start, end,
EXTENT_DIRTY, 0)) {
unlock_page(page);
continue;
}
}
clear_page_dirty_for_io(page);
unlock_page(page);
}
return 0;
}
EXPORT_SYMBOL(clear_extent_buffer_dirty);
int wait_on_extent_buffer_writeback(struct extent_map_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_map_tree *tree,
struct extent_buffer *eb)
{
return set_range_dirty(tree, eb->start, eb->start + eb->len - 1);
}
EXPORT_SYMBOL(set_extent_buffer_dirty);
int set_extent_buffer_uptodate(struct extent_map_tree *tree,
struct extent_buffer *eb)
{
unsigned long i;
struct page *page;
unsigned long num_pages;
num_pages = ((eb->start + eb->len - 1) >> PAGE_CACHE_SHIFT) -
(eb->start >> PAGE_CACHE_SHIFT) + 1;
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 - 1) & (PAGE_CACHE_SIZE - 1)))) {
check_page_uptodate(tree, page);
continue;
}
SetPageUptodate(page);
}
return 0;
}
EXPORT_SYMBOL(set_extent_buffer_uptodate);
int extent_buffer_uptodate(struct extent_map_tree *tree,
struct extent_buffer *eb)
{
if (eb->flags & EXTENT_UPTODATE)
return 1;
return test_range_bit(tree, eb->start, eb->start + eb->len - 1,
EXTENT_UPTODATE, 1);
}
EXPORT_SYMBOL(extent_buffer_uptodate);
int read_extent_buffer_pages(struct extent_map_tree *tree,
struct extent_buffer *eb, int wait)
{
unsigned long i;
struct page *page;
int err;
int ret = 0;
unsigned long num_pages;
if (eb->flags & EXTENT_UPTODATE)
return 0;
if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
EXTENT_UPTODATE, 1)) {
return 0;
}
num_pages = ((eb->start + eb->len - 1) >> PAGE_CACHE_SHIFT) -
(eb->start >> PAGE_CACHE_SHIFT) + 1;
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if (PageUptodate(page)) {
continue;
}
if (!wait) {
if (TestSetPageLocked(page)) {
continue;
}
} else {
lock_page(page);
}
if (!PageUptodate(page)) {
err = page->mapping->a_ops->readpage(NULL, page);
if (err) {
ret = err;
}
} else {
unlock_page(page);
}
}
if (ret || !wait) {
return ret;
}
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
wait_on_page_locked(page);
if (!PageUptodate(page)) {
ret = -EIO;
}
}
eb->flags |= EXTENT_UPTODATE;
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 & ((unsigned long)PAGE_CACHE_SIZE - 1);
if (i == 0)
offset += start_offset;
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);
memcpy(dst, kaddr + offset, cur);
kunmap_atomic(kaddr, KM_USER0);
dst += cur;
len -= cur;
offset = 0;
i++;
}
}
EXPORT_SYMBOL(read_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)
{
size_t offset = start & (PAGE_CACHE_SIZE - 1);
char *kaddr;
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) >>
PAGE_CACHE_SHIFT;
if (i != end_i)
return -EINVAL;
WARN_ON(start > eb->len);
if (i == 0) {
offset = start_offset;
*map_start = 0;
} else {
*map_start = (i << PAGE_CACHE_SHIFT) - start_offset;
}
kaddr = kmap_atomic(extent_buffer_page(eb, i), km);
*token = kaddr;
*map = kaddr + offset;
*map_len = PAGE_CACHE_SIZE - offset;
return 0;
}
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 & ((unsigned long)PAGE_CACHE_SIZE - 1);
if (i == 0)
offset += start_offset;
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);
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 & ((unsigned long)PAGE_CACHE_SIZE - 1);
if (i == 0)
offset += start_offset;
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);
memcpy(kaddr + offset, src, cur);
kunmap_atomic(kaddr, KM_USER0);
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 & ((unsigned long)PAGE_CACHE_SIZE - 1);
if (i == 0)
offset += start_offset;
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 = dst_offset & ((unsigned long)PAGE_CACHE_SIZE - 1);
if (i == 0)
offset += start_offset;
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_USER1);
read_extent_buffer(src, kaddr + offset, src_offset, cur);
kunmap_atomic(kaddr, KM_USER1);
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 = dst_offset &
((unsigned long)PAGE_CACHE_SIZE - 1);
src_off_in_page = 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;
if (src_i == 0)
src_off_in_page += start_offset;
if (dst_i == 0)
dst_off_in_page += start_offset;
cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
src_off_in_page));
cur = min(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 = dst_end &
((unsigned long)PAGE_CACHE_SIZE - 1);
src_off_in_page = src_end &
((unsigned long)PAGE_CACHE_SIZE - 1);
if (src_i == 0)
src_off_in_page += start_offset;
if (dst_i == 0)
dst_off_in_page += start_offset;
cur = min(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 - 1;
src_end -= cur - 1;
len -= cur;
}
}
EXPORT_SYMBOL(memmove_extent_buffer);
