1819 lines
45 KiB
C
1819 lines
45 KiB
C
#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;
|
|
|
|
struct tree_entry {
|
|
u64 start;
|
|
u64 end;
|
|
int in_tree;
|
|
struct rb_node rb_node;
|
|
};
|
|
|
|
/* bits for the extent state */
|
|
#define EXTENT_DIRTY 1
|
|
#define EXTENT_WRITEBACK (1 << 1)
|
|
#define EXTENT_UPTODATE (1 << 2)
|
|
#define EXTENT_LOCKED (1 << 3)
|
|
#define EXTENT_NEW (1 << 4)
|
|
#define EXTENT_DELALLOC (1 << 5)
|
|
|
|
#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
|
|
|
|
void __init extent_map_init(void)
|
|
{
|
|
extent_map_cache = btrfs_cache_create("extent_map",
|
|
sizeof(struct extent_map),
|
|
SLAB_DESTROY_BY_RCU,
|
|
NULL);
|
|
extent_state_cache = btrfs_cache_create("extent_state",
|
|
sizeof(struct extent_state),
|
|
SLAB_DESTROY_BY_RCU,
|
|
NULL);
|
|
}
|
|
|
|
void __exit extent_map_exit(void)
|
|
{
|
|
if (extent_map_cache)
|
|
kmem_cache_destroy(extent_map_cache);
|
|
if (extent_state_cache)
|
|
kmem_cache_destroy(extent_state_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;
|
|
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;
|
|
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)) {
|
|
WARN_ON(state->in_tree);
|
|
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 == 0 && prev->block_start == 0) ||
|
|
(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;
|
|
if ((end & 4095) == 0) {
|
|
printk("insert state %Lu %Lu strange end\n", start, end);
|
|
WARN_ON(1);
|
|
}
|
|
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;
|
|
if ((prealloc->end & 4095) == 0) {
|
|
printk("insert state %Lu %Lu strange end\n", prealloc->start,
|
|
prealloc->end);
|
|
WARN_ON(1);
|
|
}
|
|
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_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);
|
|
|
|
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.
|
|
*/
|
|
static 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;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
} 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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
if (!PagePrivate(page)) {
|
|
SetPagePrivate(page);
|
|
WARN_ON(!page->mapping->a_ops->invalidatepage);
|
|
set_page_private(page, 1);
|
|
page_cache_get(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 == 0) {
|
|
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);
|
|
}
|
|
|
|
if (!PagePrivate(page)) {
|
|
SetPagePrivate(page);
|
|
set_page_private(page, 1);
|
|
WARN_ON(!page->mapping->a_ops->invalidatepage);
|
|
page_cache_get(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 == 0 || 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);
|
|
ret = tree->ops->writepage_io_hook(page, cur, cur + iosize - 1);
|
|
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:
|
|
WARN_ON(test_range_bit(tree, start, page_end, EXTENT_DIRTY, 0));
|
|
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;
|
|
|
|
if (!PagePrivate(page)) {
|
|
SetPagePrivate(page);
|
|
set_page_private(page, 1);
|
|
WARN_ON(!page->mapping->a_ops->invalidatepage);
|
|
page_cache_get(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;
|
|
|
|
if (!PagePrivate(page)) {
|
|
SetPagePrivate(page);
|
|
set_page_private(page, 1);
|
|
WARN_ON(!page->mapping->a_ops->invalidatepage);
|
|
page_cache_get(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);
|
|
|