Btrfs: Split the extent_map code into two parts
There is now extent_map for mapping offsets in the file to disk and
extent_io for state tracking, IO submission and extent_bufers.
The new extent_map code shifts from [start,end] pairs to [start,len], and
pushes the locking out into the caller. This allows a few performance
optimizations and is easier to use.
A number of extent_map usage bugs were fixed, mostly with failing
to remove extent_map entries when changing the file.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 010a287..268ad8f 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -1,17 +1,10 @@
-#include <linux/bitops.h>
-#include <linux/slab.h>
-#include <linux/bio.h>
-#include <linux/mm.h>
+#include <linux/err.h>
#include <linux/gfp.h>
-#include <linux/pagemap.h>
-#include <linux/page-flags.h>
+#include <linux/slab.h>
#include <linux/module.h>
#include <linux/spinlock.h>
-#include <linux/blkdev.h>
-#include <linux/swap.h>
#include <linux/version.h>
-#include <linux/writeback.h>
-#include <linux/pagevec.h>
+#include <linux/hardirq.h>
#include "extent_map.h"
/* temporary define until extent_map moves out of btrfs */
@@ -21,27 +14,6 @@
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(buffers);
-static LIST_HEAD(states);
-
-static spinlock_t state_lock = SPIN_LOCK_UNLOCKED;
-#define BUFFER_LRU_MAX 64
-
-struct tree_entry {
- u64 start;
- u64 end;
- int in_tree;
- struct rb_node rb_node;
-};
-
-struct extent_page_data {
- struct bio *bio;
- struct extent_map_tree *tree;
- get_extent_t *get_extent;
-};
int __init extent_map_init(void)
{
@@ -50,72 +22,23 @@
NULL);
if (!extent_map_cache)
return -ENOMEM;
- extent_state_cache = btrfs_cache_create("extent_state",
- sizeof(struct extent_state), 0,
- NULL);
- if (!extent_state_cache)
- goto free_map_cache;
- extent_buffer_cache = btrfs_cache_create("extent_buffers",
- sizeof(struct extent_buffer), 0,
- NULL);
- if (!extent_buffer_cache)
- goto free_state_cache;
return 0;
-
-free_state_cache:
- kmem_cache_destroy(extent_state_cache);
-free_map_cache:
- kmem_cache_destroy(extent_map_cache);
- return -ENOMEM;
}
void extent_map_exit(void)
{
- struct extent_state *state;
-
- 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);
-
- }
-
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)
+void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask)
{
tree->map.rb_node = NULL;
- tree->state.rb_node = NULL;
- tree->ops = NULL;
- tree->dirty_bytes = 0;
- rwlock_init(&tree->lock);
- spin_lock_init(&tree->lru_lock);
- tree->mapping = mapping;
- INIT_LIST_HEAD(&tree->buffer_lru);
- tree->lru_size = 0;
+ tree->last = NULL;
+ spin_lock_init(&tree->lock);
}
EXPORT_SYMBOL(extent_map_tree_init);
-void extent_map_tree_empty_lru(struct extent_map_tree *tree)
-{
- struct extent_buffer *eb;
- while(!list_empty(&tree->buffer_lru)) {
- eb = list_entry(tree->buffer_lru.next, struct extent_buffer,
- lru);
- list_del_init(&eb->lru);
- free_extent_buffer(eb);
- }
-}
-EXPORT_SYMBOL(extent_map_tree_empty_lru);
-
struct extent_map *alloc_extent_map(gfp_t mask)
{
struct extent_map *em;
@@ -123,6 +46,7 @@
if (!em || IS_ERR(em))
return em;
em->in_tree = 0;
+ em->flags = 0;
atomic_set(&em->refs, 1);
return em;
}
@@ -132,6 +56,7 @@
{
if (!em)
return;
+ WARN_ON(atomic_read(&em->refs) == 0);
if (atomic_dec_and_test(&em->refs)) {
WARN_ON(em->in_tree);
kmem_cache_free(extent_map_cache, em);
@@ -139,64 +64,28 @@
}
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;
+ struct extent_map *entry;
while(*p) {
parent = *p;
- entry = rb_entry(parent, struct tree_entry, rb_node);
+ entry = rb_entry(parent, struct extent_map, rb_node);
+
+ WARN_ON(!entry->in_tree);
if (offset < entry->start)
p = &(*p)->rb_left;
- else if (offset > entry->end)
+ else if (offset >= extent_map_end(entry))
p = &(*p)->rb_right;
else
return parent;
}
- entry = rb_entry(node, struct tree_entry, rb_node);
+ entry = rb_entry(node, struct extent_map, rb_node);
entry->in_tree = 1;
rb_link_node(node, parent, p);
rb_insert_color(node, root);
@@ -210,17 +99,19 @@
struct rb_node * n = root->rb_node;
struct rb_node *prev = NULL;
struct rb_node *orig_prev = NULL;
- struct tree_entry *entry;
- struct tree_entry *prev_entry = NULL;
+ struct extent_map *entry;
+ struct extent_map *prev_entry = NULL;
while(n) {
- entry = rb_entry(n, struct tree_entry, rb_node);
+ entry = rb_entry(n, struct extent_map, rb_node);
prev = n;
prev_entry = entry;
+ WARN_ON(!entry->in_tree);
+
if (offset < entry->start)
n = n->rb_left;
- else if (offset > entry->end)
+ else if (offset >= extent_map_end(entry))
n = n->rb_right;
else
return n;
@@ -228,19 +119,19 @@
if (prev_ret) {
orig_prev = prev;
- while(prev && offset > prev_entry->end) {
+ while(prev && offset >= extent_map_end(prev_entry)) {
prev = rb_next(prev);
- prev_entry = rb_entry(prev, struct tree_entry, rb_node);
+ prev_entry = rb_entry(prev, struct extent_map, rb_node);
}
*prev_ret = prev;
prev = orig_prev;
}
if (next_ret) {
- prev_entry = rb_entry(prev, struct tree_entry, rb_node);
+ prev_entry = rb_entry(prev, struct extent_map, rb_node);
while(prev && offset < prev_entry->start) {
prev = rb_prev(prev);
- prev_entry = rb_entry(prev, struct tree_entry, rb_node);
+ prev_entry = rb_entry(prev, struct extent_map, rb_node);
}
*next_ret = prev;
}
@@ -257,22 +148,26 @@
return ret;
}
-static int tree_delete(struct rb_root *root, u64 offset)
+static int mergable_maps(struct extent_map *prev, struct extent_map *next)
{
- struct rb_node *node;
- struct tree_entry *entry;
-
- node = __tree_search(root, offset, NULL, NULL);
- if (!node)
- return -ENOENT;
- entry = rb_entry(node, struct tree_entry, rb_node);
- entry->in_tree = 0;
- rb_erase(node, root);
+ if (extent_map_end(prev) == next->start &&
+ prev->flags == next->flags &&
+ prev->bdev == next->bdev &&
+ ((next->block_start == EXTENT_MAP_HOLE &&
+ prev->block_start == EXTENT_MAP_HOLE) ||
+ (next->block_start == EXTENT_MAP_INLINE &&
+ prev->block_start == EXTENT_MAP_INLINE) ||
+ (next->block_start == EXTENT_MAP_DELALLOC &&
+ prev->block_start == EXTENT_MAP_DELALLOC) ||
+ (next->block_start < EXTENT_MAP_LAST_BYTE - 1 &&
+ next->block_start == extent_map_block_end(prev)))) {
+ return 1;
+ }
return 0;
}
/*
- * add_extent_mapping tries a simple backward merge with existing
+ * add_extent_mapping tries a simple forward/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).
*/
@@ -280,13 +175,12 @@
struct extent_map *em)
{
int ret = 0;
- struct extent_map *prev = NULL;
+ struct extent_map *merge = NULL;
struct rb_node *rb;
- write_lock_irq(&tree->lock);
- rb = tree_insert(&tree->map, em->end, &em->rb_node);
+ rb = tree_insert(&tree->map, em->start, &em->rb_node);
if (rb) {
- prev = rb_entry(rb, struct extent_map, rb_node);
+ merge = rb_entry(rb, struct extent_map, rb_node);
ret = -EEXIST;
goto out;
}
@@ -294,53 +188,60 @@
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 == EXTENT_MAP_INLINE &&
- prev->block_start == EXTENT_MAP_INLINE) ||
- (em->block_start == EXTENT_MAP_DELALLOC &&
- prev->block_start == EXTENT_MAP_DELALLOC) ||
- (em->block_start < EXTENT_MAP_DELALLOC - 1 &&
- 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);
+ merge = rb_entry(rb, struct extent_map, rb_node);
+ if (rb && mergable_maps(merge, em)) {
+ em->start = merge->start;
+ em->len += merge->len;
+ em->block_start = merge->block_start;
+ merge->in_tree = 0;
+ rb_erase(&merge->rb_node, &tree->map);
+ free_extent_map(merge);
}
}
+ rb = rb_next(&em->rb_node);
+ if (rb)
+ merge = rb_entry(rb, struct extent_map, rb_node);
+ if (rb && mergable_maps(em, merge)) {
+ em->len += merge->len;
+ rb_erase(&merge->rb_node, &tree->map);
+ merge->in_tree = 0;
+ free_extent_map(merge);
+ }
+ tree->last = em;
out:
- write_unlock_irq(&tree->lock);
return ret;
}
EXPORT_SYMBOL(add_extent_mapping);
+static u64 range_end(u64 start, u64 len)
+{
+ if (start + len < start)
+ return (u64)-1;
+ return start + len;
+}
+
/*
* lookup_extent_mapping returns the first extent_map struct in the
- * tree that intersects the [start, end] (inclusive) range. There may
+ * tree that intersects the [start, len] 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)
+ u64 start, u64 len)
{
struct extent_map *em;
struct rb_node *rb_node;
- struct rb_node *prev = NULL;
- struct rb_node *next = NULL;
+ struct rb_node *prev = NULL; struct rb_node *next = NULL; u64 end = range_end(start, len); em = tree->last; if (em && end > em->start && start < extent_map_end(em)) goto found;
- read_lock_irq(&tree->lock);
rb_node = __tree_search(&tree->map, start, &prev, &next);
if (!rb_node && prev) {
em = rb_entry(prev, struct extent_map, rb_node);
- if (em->start <= end && em->end >= start)
+ if (end > em->start && start < extent_map_end(em))
goto found;
}
if (!rb_node && next) {
em = rb_entry(next, struct extent_map, rb_node);
- if (em->start <= end && em->end >= start)
+ if (end > em->start && start < extent_map_end(em))
goto found;
}
if (!rb_node) {
@@ -352,14 +253,16 @@
goto out;
}
em = rb_entry(rb_node, struct extent_map, rb_node);
- if (em->end < start || em->start > end) {
- em = NULL;
- goto out;
- }
+ if (end > em->start && start < extent_map_end(em))
+ goto found;
+
+ em = NULL;
+ goto out;
+
found:
atomic_inc(&em->refs);
+ tree->last = em;
out:
- read_unlock_irq(&tree->lock);
return em;
}
EXPORT_SYMBOL(lookup_extent_mapping);
@@ -370,2866 +273,12 @@
*/
int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
{
- int ret;
+ int ret = 0;
- write_lock_irq(&tree->lock);
- ret = tree_delete(&tree->map, em->end);
- write_unlock_irq(&tree->lock);
+ rb_erase(&em->rb_node, &tree->map);
+ em->in_tree = 0;
+ if (tree->last == em)
+ tree->last = NULL;
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);
- }
- if (bits & EXTENT_DIRTY)
- tree->dirty_bytes += end - start + 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;
-
- if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
- u64 range = state->end - state->start + 1;
- WARN_ON(range > tree->dirty_bytes);
- tree->dirty_bytes -= range;
- }
- 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);
-
-static void set_state_bits(struct extent_map_tree *tree,
- struct extent_state *state,
- int bits)
-{
- if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
- u64 range = state->end - state->start + 1;
- tree->dirty_bytes += range;
- }
- state->state |= bits;
-}
-
-/*
- * set some bits on a range in the tree. This may require allocations
- * or sleeping, so the gfp mask is used to indicate what is allowed.
- *
- * If 'exclusive' == 1, this will fail with -EEXIST if some part of the
- * range already has the desired bits set. The start of the existing
- * range is returned in failed_start in this case.
- *
- * [start, end] is inclusive
- * This takes the tree lock.
- */
-int set_extent_bit(struct extent_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;
- }
- set_state_bits(tree, state, bits);
- start = state->end + 1;
- merge_state(tree, state);
- goto search_again;
- }
-
- /*
- * | ---- desired range ---- |
- * | state |
- * or
- * | ------------- state -------------- |
- *
- * We need to split the extent we found, and may flip bits on
- * second half.
- *
- * If the extent we found extends past our
- * range, we just split and search again. It'll get split
- * again the next time though.
- *
- * If the extent we found is inside our range, we set the
- * desired bit on it.
- */
- if (state->start < start) {
- set = state->state & bits;
- if (exclusive && set) {
- *failed_start = start;
- err = -EEXIST;
- goto out;
- }
- err = split_state(tree, state, prealloc, start);
- BUG_ON(err == -EEXIST);
- prealloc = NULL;
- if (err)
- goto out;
- if (state->end <= end) {
- set_state_bits(tree, state, bits);
- start = state->end + 1;
- merge_state(tree, state);
- } else {
- start = state->start;
- }
- goto search_again;
- }
- /*
- * | ---- desired range ---- |
- * | state | or | state |
- *
- * There's a hole, we need to insert something in it and
- * ignore the extent we found.
- */
- if (state->start > start) {
- u64 this_end;
- if (end < last_start)
- this_end = end;
- else
- this_end = last_start -1;
- err = insert_state(tree, prealloc, start, this_end,
- bits);
- prealloc = NULL;
- BUG_ON(err == -EEXIST);
- if (err)
- goto out;
- start = this_end + 1;
- goto search_again;
- }
- /*
- * | ---- desired range ---- |
- * | state |
- * We need to split the extent, and set the bit
- * on the first half
- */
- if (state->start <= end && state->end > end) {
- set = state->state & bits;
- if (exclusive && set) {
- *failed_start = start;
- err = -EEXIST;
- goto out;
- }
- err = split_state(tree, state, prealloc, end + 1);
- BUG_ON(err == -EEXIST);
-
- set_state_bits(tree, prealloc, bits);
- merge_state(tree, prealloc);
- prealloc = NULL;
- goto out;
- }
-
- goto search_again;
-
-out:
- 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;
-
- 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)) {
- goto out;
- }
-
- while(1) {
- state = rb_entry(node, struct extent_state, rb_node);
- if (state->end >= start && (state->state & bits)) {
- *start_ret = state->start;
- *end_ret = state->end;
- ret = 0;
- break;
- }
- node = rb_next(node);
- if (!node)
- break;
- }
-out:
- read_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 *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)) {
- *end = (u64)-1;
- goto out;
- }
-
- while(1) {
- state = rb_entry(node, struct extent_state, rb_node);
- if (found && state->start != cur_start) {
- goto out;
- }
- if (!(state->state & EXTENT_DELALLOC)) {
- if (!found)
- *end = state->end;
- goto out;
- }
- if (!found) {
- struct extent_state *prev_state;
- struct rb_node *prev_node = node;
- while(1) {
- prev_node = rb_prev(prev_node);
- if (!prev_node)
- break;
- prev_state = rb_entry(prev_node,
- struct extent_state,
- rb_node);
- if (!(prev_state->state & EXTENT_DELALLOC))
- break;
- state = prev_state;
- node = prev_node;
- }
- }
- if (state->state & EXTENT_LOCKED) {
- DEFINE_WAIT(wait);
- atomic_inc(&state->refs);
- prepare_to_wait(&state->wq, &wait,
- TASK_UNINTERRUPTIBLE);
- 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;
- if (!found)
- *start = state->start;
- found++;
- *end = state->end;
- cur_start = state->end + 1;
- node = rb_next(node);
- if (!node)
- break;
- total_bytes += state->end - state->start + 1;
- if (total_bytes >= max_bytes)
- break;
- }
-out:
- write_unlock_irq(&tree->lock);
- return found;
-}
-
-u64 count_range_bits(struct extent_map_tree *tree,
- u64 *start, u64 search_end, u64 max_bytes,
- unsigned long bits)
-{
- struct rb_node *node;
- struct extent_state *state;
- u64 cur_start = *start;
- u64 total_bytes = 0;
- int found = 0;
-
- if (search_end <= cur_start) {
- printk("search_end %Lu start %Lu\n", search_end, cur_start);
- WARN_ON(1);
- return 0;
- }
-
- write_lock_irq(&tree->lock);
- if (cur_start == 0 && bits == EXTENT_DIRTY) {
- total_bytes = tree->dirty_bytes;
- goto out;
- }
- /*
- * this search will find all the extents that end after
- * our range starts.
- */
- node = tree_search(&tree->state, cur_start);
- if (!node || IS_ERR(node)) {
- goto out;
- }
-
- while(1) {
- state = rb_entry(node, struct extent_state, rb_node);
- if (state->start > search_end)
- break;
- if (state->end >= cur_start && (state->state & bits)) {
- total_bytes += min(search_end, state->end) + 1 -
- max(cur_start, state->start);
- if (total_bytes >= max_bytes)
- break;
- if (!found) {
- *start = state->start;
- found = 1;
- }
- }
- node = rb_next(node);
- if (!node)
- break;
- }
-out:
- write_unlock_irq(&tree->lock);
- return total_bytes;
-}
-/*
- * helper function to lock both pages and extents in the tree.
- * pages must be locked first.
- */
-int lock_range(struct extent_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 (filled && state->start > start) {
- bitset = 0;
- break;
- }
-
- if (state->start > end)
- break;
-
- if (state->state & bits) {
- bitset = 1;
- if (!filled)
- break;
- } else if (filled) {
- bitset = 0;
- break;
- }
- start = state->end + 1;
- if (start > end)
- break;
- node = rb_next(node);
- if (!node) {
- if (filled)
- bitset = 0;
- break;
- }
- }
- 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 = (u64)page->index << PAGE_CACHE_SHIFT;
- u64 end = start + PAGE_CACHE_SIZE - 1;
- if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
- SetPageUptodate(page);
- return 0;
-}
-
-/*
- * helper function to unlock a page if all the extents in the tree
- * for that page are unlocked
- */
-static int check_page_locked(struct extent_map_tree *tree,
- struct page *page)
-{
- u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
- u64 end = start + PAGE_CACHE_SIZE - 1;
- if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
- unlock_page(page);
- return 0;
-}
-
-/*
- * helper function to end page writeback if all the extents
- * in the tree for that page are done with writeback
- */
-static int check_page_writeback(struct extent_map_tree *tree,
- struct page *page)
-{
- u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
- u64 end = start + PAGE_CACHE_SIZE - 1;
- if (!test_range_bit(tree, start, end, EXTENT_WRITEBACK, 0))
- end_page_writeback(page);
- return 0;
-}
-
-/* lots and lots of room for performance fixes in the end_bio funcs */
-
-/*
- * after a writepage IO is done, we need to:
- * clear the uptodate bits on error
- * clear the writeback bits in the extent tree for this IO
- * end_page_writeback if the page has no more pending IO
- *
- * Scheduling is not allowed, so the extent state tree is expected
- * to have one and only one object corresponding to this IO.
- */
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
-static void end_bio_extent_writepage(struct bio *bio, int err)
-#else
-static int end_bio_extent_writepage(struct bio *bio,
- unsigned int bytes_done, int err)
-#endif
-{
- 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 LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
- if (bio->bi_size)
- return 1;
-#endif
-
- do {
- struct page *page = bvec->bv_page;
- start = ((u64)page->index << PAGE_CACHE_SHIFT) +
- bvec->bv_offset;
- end = start + bvec->bv_len - 1;
-
- if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
- whole_page = 1;
- else
- whole_page = 0;
-
- if (--bvec >= bio->bi_io_vec)
- prefetchw(&bvec->bv_page->flags);
-
- if (!uptodate) {
- 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);
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
- return 0;
-#endif
-}
-
-/*
- * after a readpage IO is done, we need to:
- * clear the uptodate bits on error
- * set the uptodate bits if things worked
- * set the page up to date if all extents in the tree are uptodate
- * clear the lock bit in the extent tree
- * unlock the page if there are no other extents locked for it
- *
- * Scheduling is not allowed, so the extent state tree is expected
- * to have one and only one object corresponding to this IO.
- */
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
-static void end_bio_extent_readpage(struct bio *bio, int err)
-#else
-static int end_bio_extent_readpage(struct bio *bio,
- unsigned int bytes_done, int err)
-#endif
-{
- int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
- struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
- struct extent_map_tree *tree = bio->bi_private;
- u64 start;
- u64 end;
- int whole_page;
- int ret;
-
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
- if (bio->bi_size)
- return 1;
-#endif
-
- do {
- struct page *page = bvec->bv_page;
- start = ((u64)page->index << PAGE_CACHE_SHIFT) +
- bvec->bv_offset;
- end = start + bvec->bv_len - 1;
-
- if (bvec->bv_offset == 0 && bvec->bv_len == PAGE_CACHE_SIZE)
- whole_page = 1;
- else
- whole_page = 0;
-
- if (--bvec >= bio->bi_io_vec)
- prefetchw(&bvec->bv_page->flags);
-
- if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
- ret = tree->ops->readpage_end_io_hook(page, start, end);
- 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);
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
- return 0;
-#endif
-}
-
-/*
- * IO done from prepare_write is pretty simple, we just unlock
- * the structs in the extent tree when done, and set the uptodate bits
- * as appropriate.
- */
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
-static void end_bio_extent_preparewrite(struct bio *bio, int err)
-#else
-static int end_bio_extent_preparewrite(struct bio *bio,
- unsigned int bytes_done, int err)
-#endif
-{
- const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
- struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
- struct extent_map_tree *tree = bio->bi_private;
- u64 start;
- u64 end;
-
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
- if (bio->bi_size)
- return 1;
-#endif
-
- do {
- struct page *page = bvec->bv_page;
- start = ((u64)page->index << PAGE_CACHE_SHIFT) +
- bvec->bv_offset;
- end = start + bvec->bv_len - 1;
-
- if (--bvec >= bio->bi_io_vec)
- prefetchw(&bvec->bv_page->flags);
-
- if (uptodate) {
- set_extent_uptodate(tree, start, end, GFP_ATOMIC);
- } else {
- ClearPageUptodate(page);
- SetPageError(page);
- }
-
- unlock_extent(tree, start, end, GFP_ATOMIC);
-
- } while (bvec >= bio->bi_io_vec);
-
- bio_put(bio);
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
- return 0;
-#endif
-}
-
-static struct bio *
-extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
- gfp_t gfp_flags)
-{
- struct bio *bio;
-
- bio = bio_alloc(gfp_flags, nr_vecs);
-
- if (bio == NULL && (current->flags & PF_MEMALLOC)) {
- while (!bio && (nr_vecs /= 2))
- bio = bio_alloc(gfp_flags, nr_vecs);
- }
-
- if (bio) {
- bio->bi_bdev = bdev;
- bio->bi_sector = first_sector;
- }
- return bio;
-}
-
-static int submit_one_bio(int rw, struct bio *bio)
-{
- u64 maxsector;
- int ret = 0;
-
- bio_get(bio);
-
- maxsector = bio->bi_bdev->bd_inode->i_size >> 9;
- if (maxsector < bio->bi_sector) {
- printk("sector too large max %Lu got %llu\n", maxsector,
- (unsigned long long)bio->bi_sector);
- WARN_ON(1);
- }
-
- submit_bio(rw, bio);
- if (bio_flagged(bio, BIO_EOPNOTSUPP))
- ret = -EOPNOTSUPP;
- bio_put(bio);
- return ret;
-}
-
-static int submit_extent_page(int rw, struct extent_map_tree *tree,
- struct page *page, sector_t sector,
- size_t size, unsigned long offset,
- struct block_device *bdev,
- struct bio **bio_ret,
- unsigned long max_pages,
- bio_end_io_t end_io_func)
-{
- int ret = 0;
- struct bio *bio;
- int nr;
-
- if (bio_ret && *bio_ret) {
- bio = *bio_ret;
- if (bio->bi_sector + (bio->bi_size >> 9) != sector ||
- bio_add_page(bio, page, size, offset) < size) {
- ret = submit_one_bio(rw, bio);
- bio = NULL;
- } else {
- return 0;
- }
- }
- nr = min_t(int, max_pages, bio_get_nr_vecs(bdev));
- bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
- if (!bio) {
- printk("failed to allocate bio nr %d\n", nr);
- }
- bio_add_page(bio, page, size, offset);
- bio->bi_end_io = end_io_func;
- bio->bi_private = tree;
- if (bio_ret) {
- *bio_ret = bio;
- } else {
- ret = submit_one_bio(rw, bio);
- }
-
- return ret;
-}
-
-void set_page_extent_mapped(struct page *page)
-{
- if (!PagePrivate(page)) {
- SetPagePrivate(page);
- WARN_ON(!page->mapping->a_ops->invalidatepage);
- set_page_private(page, EXTENT_PAGE_PRIVATE);
- page_cache_get(page);
- }
-}
-
-void set_page_extent_head(struct page *page, unsigned long len)
-{
- set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
-}
-
-/*
- * basic readpage implementation. Locked extent state structs are inserted
- * into the tree that are removed when the IO is done (by the end_io
- * handlers)
- */
-static int __extent_read_full_page(struct extent_map_tree *tree,
- struct page *page,
- get_extent_t *get_extent,
- struct bio **bio)
-{
- struct inode *inode = page->mapping->host;
- u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
- u64 page_end = start + PAGE_CACHE_SIZE - 1;
- u64 end;
- u64 cur = start;
- u64 extent_offset;
- u64 last_byte = i_size_read(inode);
- u64 block_start;
- u64 cur_end;
- sector_t sector;
- struct extent_map *em;
- struct block_device *bdev;
- int ret;
- int nr = 0;
- size_t page_offset = 0;
- size_t iosize;
- size_t blocksize = inode->i_sb->s_blocksize;
-
- set_page_extent_mapped(page);
-
- end = page_end;
- lock_extent(tree, start, end, GFP_NOFS);
-
- while (cur <= end) {
- if (cur >= last_byte) {
- char *userpage;
- iosize = PAGE_CACHE_SIZE - page_offset;
- userpage = kmap_atomic(page, KM_USER0);
- memset(userpage + page_offset, 0, iosize);
- flush_dcache_page(page);
- kunmap_atomic(userpage, KM_USER0);
- set_extent_uptodate(tree, cur, cur + iosize - 1,
- GFP_NOFS);
- unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
- break;
- }
- em = get_extent(inode, page, page_offset, cur, end, 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) {
- char *userpage;
- userpage = kmap_atomic(page, KM_USER0);
- memset(userpage + page_offset, 0, iosize);
- flush_dcache_page(page);
- kunmap_atomic(userpage, KM_USER0);
-
- set_extent_uptodate(tree, cur, cur + iosize - 1,
- GFP_NOFS);
- unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
- cur = cur + iosize;
- page_offset += iosize;
- continue;
- }
- /* the get_extent function already copied into the page */
- if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
- unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
- cur = cur + iosize;
- page_offset += iosize;
- continue;
- }
-
- ret = 0;
- if (tree->ops && tree->ops->readpage_io_hook) {
- ret = tree->ops->readpage_io_hook(page, cur,
- cur + iosize - 1);
- }
- if (!ret) {
- unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
- nr -= page->index;
- ret = submit_extent_page(READ, tree, page,
- sector, iosize, page_offset,
- bdev, bio, nr,
- end_bio_extent_readpage);
- }
- if (ret)
- SetPageError(page);
- cur = cur + iosize;
- page_offset += iosize;
- nr++;
- }
- if (!nr) {
- if (!PageError(page))
- SetPageUptodate(page);
- unlock_page(page);
- }
- return 0;
-}
-
-int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
- get_extent_t *get_extent)
-{
- struct bio *bio = NULL;
- int ret;
-
- ret = __extent_read_full_page(tree, page, get_extent, &bio);
- if (bio)
- submit_one_bio(READ, bio);
- return ret;
-}
-EXPORT_SYMBOL(extent_read_full_page);
-
-/*
- * the writepage semantics are similar to regular writepage. extent
- * records are inserted to lock ranges in the tree, and as dirty areas
- * are found, they are marked writeback. Then the lock bits are removed
- * and the end_io handler clears the writeback ranges
- */
-static int __extent_writepage(struct page *page, struct writeback_control *wbc,
- void *data)
-{
- struct inode *inode = page->mapping->host;
- struct extent_page_data *epd = data;
- struct extent_map_tree *tree = epd->tree;
- u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
- u64 delalloc_start;
- u64 page_end = start + PAGE_CACHE_SIZE - 1;
- u64 end;
- u64 cur = start;
- u64 extent_offset;
- u64 last_byte = i_size_read(inode);
- u64 block_start;
- u64 iosize;
- sector_t sector;
- struct extent_map *em;
- struct block_device *bdev;
- int ret;
- int nr = 0;
- size_t page_offset = 0;
- size_t blocksize;
- loff_t i_size = i_size_read(inode);
- unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
- u64 nr_delalloc;
- u64 delalloc_end;
-
- WARN_ON(!PageLocked(page));
- if (page->index > end_index) {
- clear_extent_dirty(tree, start, page_end, GFP_NOFS);
- unlock_page(page);
- return 0;
- }
-
- if (page->index == end_index) {
- char *userpage;
-
- size_t offset = i_size & (PAGE_CACHE_SIZE - 1);
-
- userpage = kmap_atomic(page, KM_USER0);
- memset(userpage + offset, 0, PAGE_CACHE_SIZE - offset);
- flush_dcache_page(page);
- kunmap_atomic(userpage, KM_USER0);
- }
-
- set_page_extent_mapped(page);
-
- delalloc_start = start;
- delalloc_end = 0;
- while(delalloc_end < page_end) {
- nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start,
- &delalloc_end,
- 128 * 1024 * 1024);
- if (nr_delalloc == 0) {
- delalloc_start = delalloc_end + 1;
- continue;
- }
- tree->ops->fill_delalloc(inode, delalloc_start,
- delalloc_end);
- clear_extent_bit(tree, delalloc_start,
- delalloc_end,
- EXTENT_LOCKED | EXTENT_DELALLOC,
- 1, 0, GFP_NOFS);
- delalloc_start = delalloc_end + 1;
- }
- lock_extent(tree, start, page_end, GFP_NOFS);
-
- 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 = epd->get_extent(inode, page, page_offset, cur, end, 1);
- 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 {
- unsigned long max_nr = end_index + 1;
- set_range_writeback(tree, cur, cur + iosize - 1);
- if (!PageWriteback(page)) {
- printk("warning page %lu not writeback, "
- "cur %llu end %llu\n", page->index,
- (unsigned long long)cur,
- (unsigned long long)end);
- }
-
- ret = submit_extent_page(WRITE, tree, page, sector,
- iosize, page_offset, bdev,
- &epd->bio, max_nr,
- end_bio_extent_writepage);
- if (ret)
- SetPageError(page);
- }
- cur = cur + iosize;
- page_offset += iosize;
- nr++;
- }
-done:
- if (nr == 0) {
- /* make sure the mapping tag for page dirty gets cleared */
- set_page_writeback(page);
- end_page_writeback(page);
- }
- unlock_extent(tree, start, page_end, GFP_NOFS);
- unlock_page(page);
- return 0;
-}
-
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
-
-/* Taken directly from 2.6.23 for 2.6.18 back port */
-typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
- void *data);
-
-/**
- * write_cache_pages - walk the list of dirty pages of the given address space
- * and write all of them.
- * @mapping: address space structure to write
- * @wbc: subtract the number of written pages from *@wbc->nr_to_write
- * @writepage: function called for each page
- * @data: data passed to writepage function
- *
- * If a page is already under I/O, write_cache_pages() skips it, even
- * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
- * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
- * and msync() need to guarantee that all the data which was dirty at the time
- * the call was made get new I/O started against them. If wbc->sync_mode is
- * WB_SYNC_ALL then we were called for data integrity and we must wait for
- * existing IO to complete.
- */
-static int write_cache_pages(struct address_space *mapping,
- struct writeback_control *wbc, writepage_t writepage,
- void *data)
-{
- struct backing_dev_info *bdi = mapping->backing_dev_info;
- int ret = 0;
- int done = 0;
- struct pagevec pvec;
- int nr_pages;
- pgoff_t index;
- pgoff_t end; /* Inclusive */
- int scanned = 0;
- int range_whole = 0;
-
- if (wbc->nonblocking && bdi_write_congested(bdi)) {
- wbc->encountered_congestion = 1;
- return 0;
- }
-
- pagevec_init(&pvec, 0);
- if (wbc->range_cyclic) {
- index = mapping->writeback_index; /* Start from prev offset */
- end = -1;
- } else {
- index = wbc->range_start >> PAGE_CACHE_SHIFT;
- end = wbc->range_end >> PAGE_CACHE_SHIFT;
- if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
- range_whole = 1;
- scanned = 1;
- }
-retry:
- while (!done && (index <= end) &&
- (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
- PAGECACHE_TAG_DIRTY,
- min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
- unsigned i;
-
- scanned = 1;
- for (i = 0; i < nr_pages; i++) {
- struct page *page = pvec.pages[i];
-
- /*
- * At this point we hold neither mapping->tree_lock nor
- * lock on the page itself: the page may be truncated or
- * invalidated (changing page->mapping to NULL), or even
- * swizzled back from swapper_space to tmpfs file
- * mapping
- */
- lock_page(page);
-
- if (unlikely(page->mapping != mapping)) {
- unlock_page(page);
- continue;
- }
-
- if (!wbc->range_cyclic && page->index > end) {
- done = 1;
- unlock_page(page);
- continue;
- }
-
- if (wbc->sync_mode != WB_SYNC_NONE)
- wait_on_page_writeback(page);
-
- if (PageWriteback(page) ||
- !clear_page_dirty_for_io(page)) {
- unlock_page(page);
- continue;
- }
-
- ret = (*writepage)(page, wbc, data);
-
- if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
- unlock_page(page);
- ret = 0;
- }
- if (ret || (--(wbc->nr_to_write) <= 0))
- done = 1;
- if (wbc->nonblocking && bdi_write_congested(bdi)) {
- wbc->encountered_congestion = 1;
- done = 1;
- }
- }
- pagevec_release(&pvec);
- cond_resched();
- }
- if (!scanned && !done) {
- /*
- * We hit the last page and there is more work to be done: wrap
- * back to the start of the file
- */
- scanned = 1;
- index = 0;
- goto retry;
- }
- if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
- mapping->writeback_index = index;
- return ret;
-}
-#endif
-
-int extent_write_full_page(struct extent_map_tree *tree, struct page *page,
- get_extent_t *get_extent,
- struct writeback_control *wbc)
-{
- int ret;
- struct address_space *mapping = page->mapping;
- struct extent_page_data epd = {
- .bio = NULL,
- .tree = tree,
- .get_extent = get_extent,
- };
- struct writeback_control wbc_writepages = {
- .bdi = wbc->bdi,
- .sync_mode = WB_SYNC_NONE,
- .older_than_this = NULL,
- .nr_to_write = 64,
- .range_start = page_offset(page) + PAGE_CACHE_SIZE,
- .range_end = (loff_t)-1,
- };
-
-
- ret = __extent_writepage(page, wbc, &epd);
-
- write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd);
- if (epd.bio) {
- submit_one_bio(WRITE, epd.bio);
- }
- return ret;
-}
-EXPORT_SYMBOL(extent_write_full_page);
-
-
-int extent_writepages(struct extent_map_tree *tree,
- struct address_space *mapping,
- get_extent_t *get_extent,
- struct writeback_control *wbc)
-{
- int ret = 0;
- struct extent_page_data epd = {
- .bio = NULL,
- .tree = tree,
- .get_extent = get_extent,
- };
-
- ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd);
- if (epd.bio) {
- submit_one_bio(WRITE, epd.bio);
- }
- return ret;
-}
-EXPORT_SYMBOL(extent_writepages);
-
-int extent_readpages(struct extent_map_tree *tree,
- struct address_space *mapping,
- struct list_head *pages, unsigned nr_pages,
- get_extent_t get_extent)
-{
- struct bio *bio = NULL;
- unsigned page_idx;
- struct pagevec pvec;
-
- pagevec_init(&pvec, 0);
- for (page_idx = 0; page_idx < nr_pages; page_idx++) {
- struct page *page = list_entry(pages->prev, struct page, lru);
-
- prefetchw(&page->flags);
- list_del(&page->lru);
- /*
- * what we want to do here is call add_to_page_cache_lru,
- * but that isn't exported, so we reproduce it here
- */
- if (!add_to_page_cache(page, mapping,
- page->index, GFP_KERNEL)) {
-
- /* open coding of lru_cache_add, also not exported */
- page_cache_get(page);
- if (!pagevec_add(&pvec, page))
- __pagevec_lru_add(&pvec);
- __extent_read_full_page(tree, page, get_extent, &bio);
- }
- page_cache_release(page);
- }
- if (pagevec_count(&pvec))
- __pagevec_lru_add(&pvec);
- BUG_ON(!list_empty(pages));
- if (bio)
- submit_one_bio(READ, bio);
- return 0;
-}
-EXPORT_SYMBOL(extent_readpages);
-
-/*
- * basic invalidatepage code, this waits on any locked or writeback
- * ranges corresponding to the page, and then deletes any extent state
- * records from the tree
- */
-int extent_invalidatepage(struct extent_map_tree *tree,
- struct page *page, unsigned long offset)
-{
- u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
- u64 end = start + PAGE_CACHE_SIZE - 1;
- size_t blocksize = page->mapping->host->i_sb->s_blocksize;
-
- start += (offset + blocksize -1) & ~(blocksize - 1);
- if (start > end)
- return 0;
-
- lock_extent(tree, start, end, GFP_NOFS);
- wait_on_extent_writeback(tree, start, end);
- clear_extent_bit(tree, start, end,
- EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
- 1, 1, GFP_NOFS);
- return 0;
-}
-EXPORT_SYMBOL(extent_invalidatepage);
-
-/*
- * simple commit_write call, set_range_dirty is used to mark both
- * the pages and the extent records as dirty
- */
-int extent_commit_write(struct extent_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 = (u64)page->index << PAGE_CACHE_SHIFT;
- u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
- u64 block_start;
- u64 orig_block_start;
- u64 block_end;
- u64 cur_end;
- struct extent_map *em;
- unsigned blocksize = 1 << inode->i_blkbits;
- size_t page_offset = 0;
- size_t block_off_start;
- size_t block_off_end;
- int err = 0;
- int iocount = 0;
- int ret = 0;
- int isnew;
-
- set_page_extent_mapped(page);
-
- block_start = (page_start + from) & ~((u64)blocksize - 1);
- block_end = (page_start + to - 1) | (blocksize - 1);
- orig_block_start = block_start;
-
- lock_extent(tree, page_start, page_end, GFP_NOFS);
- while(block_start <= block_end) {
- em = get_extent(inode, page, page_offset, block_start,
- block_end, 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 ((em->block_start != EXTENT_MAP_HOLE &&
- em->block_start != EXTENT_MAP_INLINE) &&
- !isnew && !PageUptodate(page) &&
- (block_off_end > to || block_off_start < from) &&
- !test_range_bit(tree, block_start, cur_end,
- EXTENT_UPTODATE, 1)) {
- u64 sector;
- u64 extent_offset = block_start - em->start;
- size_t iosize;
- sector = (em->block_start + extent_offset) >> 9;
- iosize = (cur_end - block_start + blocksize) &
- ~((u64)blocksize - 1);
- /*
- * we've already got the extent locked, but we
- * need to split the state such that our end_bio
- * handler can clear the lock.
- */
- set_extent_bit(tree, block_start,
- block_start + iosize - 1,
- EXTENT_LOCKED, 0, NULL, GFP_NOFS);
- ret = submit_extent_page(READ, tree, page,
- sector, iosize, page_offset, em->bdev,
- NULL, 1,
- end_bio_extent_preparewrite);
- 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 = (u64)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;
- sector_t sector = 0;
- 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)
- goto out;
-
- sector = (em->block_start + start - em->start) >> inode->i_blkbits;
-out:
- free_extent_map(em);
- return sector;
-}
-
-static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb)
-{
- if (list_empty(&eb->lru)) {
- extent_buffer_get(eb);
- list_add(&eb->lru, &tree->buffer_lru);
- tree->lru_size++;
- if (tree->lru_size >= BUFFER_LRU_MAX) {
- struct extent_buffer *rm;
- rm = list_entry(tree->buffer_lru.prev,
- struct extent_buffer, lru);
- tree->lru_size--;
- list_del_init(&rm->lru);
- free_extent_buffer(rm);
- }
- } else
- list_move(&eb->lru, &tree->buffer_lru);
- return 0;
-}
-static struct extent_buffer *find_lru(struct extent_map_tree *tree,
- u64 start, unsigned long len)
-{
- struct list_head *lru = &tree->buffer_lru;
- struct list_head *cur = lru->next;
- struct extent_buffer *eb;
-
- if (list_empty(lru))
- return NULL;
-
- do {
- eb = list_entry(cur, struct extent_buffer, lru);
- if (eb->start == start && eb->len == len) {
- extent_buffer_get(eb);
- return eb;
- }
- cur = cur->next;
- } while (cur != lru);
- return NULL;
-}
-
-static inline unsigned long num_extent_pages(u64 start, u64 len)
-{
- return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
- (start >> PAGE_CACHE_SHIFT);
-}
-
-static inline struct page *extent_buffer_page(struct extent_buffer *eb,
- unsigned long i)
-{
- struct page *p;
- struct address_space *mapping;
-
- if (i == 0)
- return eb->first_page;
- i += eb->start >> PAGE_CACHE_SHIFT;
- mapping = eb->first_page->mapping;
- read_lock_irq(&mapping->tree_lock);
- p = radix_tree_lookup(&mapping->page_tree, i);
- read_unlock_irq(&mapping->tree_lock);
- return p;
-}
-
-static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree,
- u64 start,
- unsigned long len,
- gfp_t mask)
-{
- struct extent_buffer *eb = NULL;
-
- spin_lock(&tree->lru_lock);
- eb = find_lru(tree, start, len);
- spin_unlock(&tree->lru_lock);
- if (eb) {
- return eb;
- }
-
- eb = kmem_cache_zalloc(extent_buffer_cache, mask);
- INIT_LIST_HEAD(&eb->lru);
- eb->start = start;
- eb->len = len;
- atomic_set(&eb->refs, 1);
-
- return eb;
-}
-
-static void __free_extent_buffer(struct extent_buffer *eb)
-{
- kmem_cache_free(extent_buffer_cache, eb);
-}
-
-struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
- u64 start, unsigned long len,
- struct page *page0,
- gfp_t mask)
-{
- unsigned long num_pages = num_extent_pages(start, len);
- unsigned long i;
- unsigned long index = start >> PAGE_CACHE_SHIFT;
- struct extent_buffer *eb;
- struct page *p;
- struct address_space *mapping = tree->mapping;
- int uptodate = 1;
-
- eb = __alloc_extent_buffer(tree, start, len, mask);
- if (!eb || IS_ERR(eb))
- return NULL;
-
- if (eb->flags & EXTENT_BUFFER_FILLED)
- goto lru_add;
-
- if (page0) {
- eb->first_page = page0;
- i = 1;
- index++;
- page_cache_get(page0);
- mark_page_accessed(page0);
- set_page_extent_mapped(page0);
- WARN_ON(!PageUptodate(page0));
- set_page_extent_head(page0, len);
- } else {
- i = 0;
- }
- for (; i < num_pages; i++, index++) {
- p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
- if (!p) {
- WARN_ON(1);
- goto fail;
- }
- set_page_extent_mapped(p);
- mark_page_accessed(p);
- if (i == 0) {
- eb->first_page = p;
- set_page_extent_head(p, len);
- } else {
- set_page_private(p, EXTENT_PAGE_PRIVATE);
- }
- if (!PageUptodate(p))
- uptodate = 0;
- unlock_page(p);
- }
- if (uptodate)
- eb->flags |= EXTENT_UPTODATE;
- eb->flags |= EXTENT_BUFFER_FILLED;
-
-lru_add:
- spin_lock(&tree->lru_lock);
- add_lru(tree, eb);
- spin_unlock(&tree->lru_lock);
- return eb;
-
-fail:
- spin_lock(&tree->lru_lock);
- list_del_init(&eb->lru);
- spin_unlock(&tree->lru_lock);
- if (!atomic_dec_and_test(&eb->refs))
- return NULL;
- for (index = 1; index < i; index++) {
- page_cache_release(extent_buffer_page(eb, index));
- }
- if (i > 0)
- page_cache_release(extent_buffer_page(eb, 0));
- __free_extent_buffer(eb);
- return NULL;
-}
-EXPORT_SYMBOL(alloc_extent_buffer);
-
-struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
- u64 start, unsigned long len,
- gfp_t mask)
-{
- unsigned long num_pages = num_extent_pages(start, len);
- unsigned long i;
- unsigned long index = start >> PAGE_CACHE_SHIFT;
- struct extent_buffer *eb;
- struct page *p;
- struct address_space *mapping = tree->mapping;
- int uptodate = 1;
-
- eb = __alloc_extent_buffer(tree, start, len, mask);
- if (!eb || IS_ERR(eb))
- return NULL;
-
- if (eb->flags & EXTENT_BUFFER_FILLED)
- goto lru_add;
-
- for (i = 0; i < num_pages; i++, index++) {
- p = find_lock_page(mapping, index);
- if (!p) {
- goto fail;
- }
- set_page_extent_mapped(p);
- mark_page_accessed(p);
-
- if (i == 0) {
- eb->first_page = p;
- set_page_extent_head(p, len);
- } else {
- set_page_private(p, EXTENT_PAGE_PRIVATE);
- }
-
- if (!PageUptodate(p))
- uptodate = 0;
- unlock_page(p);
- }
- if (uptodate)
- eb->flags |= EXTENT_UPTODATE;
- eb->flags |= EXTENT_BUFFER_FILLED;
-
-lru_add:
- spin_lock(&tree->lru_lock);
- add_lru(tree, eb);
- spin_unlock(&tree->lru_lock);
- return eb;
-fail:
- spin_lock(&tree->lru_lock);
- list_del_init(&eb->lru);
- spin_unlock(&tree->lru_lock);
- if (!atomic_dec_and_test(&eb->refs))
- return NULL;
- for (index = 1; index < i; index++) {
- page_cache_release(extent_buffer_page(eb, index));
- }
- if (i > 0)
- page_cache_release(extent_buffer_page(eb, 0));
- __free_extent_buffer(eb);
- return NULL;
-}
-EXPORT_SYMBOL(find_extent_buffer);
-
-void free_extent_buffer(struct extent_buffer *eb)
-{
- unsigned long i;
- unsigned long num_pages;
-
- if (!eb)
- return;
-
- if (!atomic_dec_and_test(&eb->refs))
- return;
-
- WARN_ON(!list_empty(&eb->lru));
- num_pages = num_extent_pages(eb->start, eb->len);
-
- for (i = 1; i < num_pages; i++) {
- page_cache_release(extent_buffer_page(eb, i));
- }
- page_cache_release(extent_buffer_page(eb, 0));
- __free_extent_buffer(eb);
-}
-EXPORT_SYMBOL(free_extent_buffer);
-
-int clear_extent_buffer_dirty(struct extent_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 = num_extent_pages(eb->start, eb->len);
-
- for (i = 0; i < num_pages; i++) {
- page = extent_buffer_page(eb, i);
- lock_page(page);
- if (i == 0)
- set_page_extent_head(page, eb->len);
- else
- set_page_private(page, EXTENT_PAGE_PRIVATE);
-
- /*
- * if we're on the last page or the first page and the
- * block isn't aligned on a page boundary, do extra checks
- * to make sure we don't clean page that is partially dirty
- */
- if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
- ((i == num_pages - 1) &&
- ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
- start = (u64)page->index << PAGE_CACHE_SHIFT;
- end = start + PAGE_CACHE_SIZE - 1;
- if (test_range_bit(tree, start, end,
- EXTENT_DIRTY, 0)) {
- unlock_page(page);
- continue;
- }
- }
- clear_page_dirty_for_io(page);
- write_lock_irq(&page->mapping->tree_lock);
- if (!PageDirty(page)) {
- radix_tree_tag_clear(&page->mapping->page_tree,
- page_index(page),
- PAGECACHE_TAG_DIRTY);
- }
- write_unlock_irq(&page->mapping->tree_lock);
- 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)
-{
- unsigned long i;
- unsigned long num_pages;
-
- num_pages = num_extent_pages(eb->start, eb->len);
- for (i = 0; i < num_pages; i++) {
- struct page *page = extent_buffer_page(eb, i);
- /* writepage may need to do something special for the
- * first page, we have to make sure page->private is
- * properly set. releasepage may drop page->private
- * on us if the page isn't already dirty.
- */
- if (i == 0) {
- lock_page(page);
- set_page_extent_head(page, eb->len);
- } else if (PagePrivate(page) &&
- page->private != EXTENT_PAGE_PRIVATE) {
- lock_page(page);
- set_page_extent_mapped(page);
- unlock_page(page);
- }
- __set_page_dirty_nobuffers(extent_buffer_page(eb, i));
- if (i == 0)
- unlock_page(page);
- }
- return set_extent_dirty(tree, eb->start,
- eb->start + eb->len - 1, GFP_NOFS);
-}
-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 = num_extent_pages(eb->start, eb->len);
-
- set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
- GFP_NOFS);
- for (i = 0; i < num_pages; i++) {
- page = extent_buffer_page(eb, i);
- if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
- ((i == num_pages - 1) &&
- ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
- check_page_uptodate(tree, page);
- continue;
- }
- SetPageUptodate(page);
- }
- return 0;
-}
-EXPORT_SYMBOL(set_extent_buffer_uptodate);
-
-int extent_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,
- u64 start,
- int wait)
-{
- unsigned long i;
- unsigned long start_i;
- struct page *page;
- int err;
- int ret = 0;
- unsigned long num_pages;
-
- if (eb->flags & EXTENT_UPTODATE)
- return 0;
-
- if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1,
- EXTENT_UPTODATE, 1)) {
- return 0;
- }
-
- if (start) {
- WARN_ON(start < eb->start);
- start_i = (start >> PAGE_CACHE_SHIFT) -
- (eb->start >> PAGE_CACHE_SHIFT);
- } else {
- start_i = 0;
- }
-
- num_pages = num_extent_pages(eb->start, eb->len);
- for (i = start_i; i < num_pages; i++) {
- page = extent_buffer_page(eb, i);
- if (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 = start_i; i < num_pages; i++) {
- page = extent_buffer_page(eb, i);
- wait_on_page_locked(page);
- if (!PageUptodate(page)) {
- ret = -EIO;
- }
- }
- if (!ret)
- eb->flags |= EXTENT_UPTODATE;
- return ret;
-}
-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;
- unsigned long num_pages = num_extent_pages(eb->start, eb->len);
-
- WARN_ON(start > eb->len);
- WARN_ON(start + len > eb->start + eb->len);
-
- offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
-
- while(len > 0) {
- page = extent_buffer_page(eb, i);
- if (!PageUptodate(page)) {
- printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len);
- WARN_ON(1);
- }
- WARN_ON(!PageUptodate(page));
-
- cur = min(len, (PAGE_CACHE_SIZE - offset));
- kaddr = kmap_atomic(page, KM_USER1);
- memcpy(dst, kaddr + offset, cur);
- kunmap_atomic(kaddr, KM_USER1);
-
- dst += cur;
- len -= cur;
- offset = 0;
- i++;
- }
-}
-EXPORT_SYMBOL(read_extent_buffer);
-
-int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
- unsigned long min_len, char **token, char **map,
- unsigned long *map_start,
- unsigned long *map_len, int km)
-{
- size_t offset = start & (PAGE_CACHE_SIZE - 1);
- char *kaddr;
- struct page *p;
- size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
- unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
- unsigned long end_i = (start_offset + start + min_len - 1) >>
- PAGE_CACHE_SHIFT;
-
- if (i != end_i)
- return -EINVAL;
-
- if (i == 0) {
- offset = start_offset;
- *map_start = 0;
- } else {
- offset = 0;
- *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
- }
- if (start + min_len > eb->len) {
-printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len);
- WARN_ON(1);
- }
-
- p = extent_buffer_page(eb, i);
- WARN_ON(!PageUptodate(p));
- kaddr = kmap_atomic(p, km);
- *token = kaddr;
- *map = kaddr + offset;
- *map_len = PAGE_CACHE_SIZE - offset;
- return 0;
-}
-EXPORT_SYMBOL(map_private_extent_buffer);
-
-int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
- unsigned long min_len,
- char **token, char **map,
- unsigned long *map_start,
- unsigned long *map_len, int km)
-{
- int err;
- int save = 0;
- if (eb->map_token) {
- unmap_extent_buffer(eb, eb->map_token, km);
- eb->map_token = NULL;
- save = 1;
- }
- err = map_private_extent_buffer(eb, start, min_len, token, map,
- map_start, map_len, km);
- if (!err && save) {
- eb->map_token = *token;
- eb->kaddr = *map;
- eb->map_start = *map_start;
- eb->map_len = *map_len;
- }
- return err;
-}
-EXPORT_SYMBOL(map_extent_buffer);
-
-void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
-{
- kunmap_atomic(token, km);
-}
-EXPORT_SYMBOL(unmap_extent_buffer);
-
-int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
- unsigned long start,
- unsigned long len)
-{
- size_t cur;
- size_t offset;
- struct page *page;
- char *kaddr;
- char *ptr = (char *)ptrv;
- size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
- unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
- int ret = 0;
-
- WARN_ON(start > eb->len);
- WARN_ON(start + len > eb->start + eb->len);
-
- offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
-
- while(len > 0) {
- page = extent_buffer_page(eb, i);
- 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_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
-
- while(len > 0) {
- page = extent_buffer_page(eb, i);
- WARN_ON(!PageUptodate(page));
-
- cur = min(len, PAGE_CACHE_SIZE - offset);
- kaddr = kmap_atomic(page, KM_USER1);
- memcpy(kaddr + offset, src, cur);
- kunmap_atomic(kaddr, KM_USER1);
-
- src += cur;
- len -= cur;
- offset = 0;
- i++;
- }
-}
-EXPORT_SYMBOL(write_extent_buffer);
-
-void memset_extent_buffer(struct extent_buffer *eb, char c,
- unsigned long start, unsigned long len)
-{
- size_t cur;
- size_t offset;
- struct page *page;
- char *kaddr;
- size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
- unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
-
- WARN_ON(start > eb->len);
- WARN_ON(start + len > eb->start + eb->len);
-
- offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);
-
- while(len > 0) {
- page = extent_buffer_page(eb, i);
- WARN_ON(!PageUptodate(page));
-
- cur = min(len, PAGE_CACHE_SIZE - offset);
- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr + offset, c, cur);
- kunmap_atomic(kaddr, KM_USER0);
-
- len -= cur;
- offset = 0;
- i++;
- }
-}
-EXPORT_SYMBOL(memset_extent_buffer);
-
-void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
- unsigned long dst_offset, unsigned long src_offset,
- unsigned long len)
-{
- u64 dst_len = dst->len;
- size_t cur;
- size_t offset;
- struct page *page;
- char *kaddr;
- size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
- unsigned long i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
-
- WARN_ON(src->len != dst_len);
-
- offset = (start_offset + dst_offset) &
- ((unsigned long)PAGE_CACHE_SIZE - 1);
-
- while(len > 0) {
- page = extent_buffer_page(dst, i);
- WARN_ON(!PageUptodate(page));
-
- cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
-
- kaddr = kmap_atomic(page, KM_USER0);
- read_extent_buffer(src, kaddr + offset, src_offset, cur);
- kunmap_atomic(kaddr, KM_USER0);
-
- src_offset += cur;
- len -= cur;
- offset = 0;
- i++;
- }
-}
-EXPORT_SYMBOL(copy_extent_buffer);
-
-static void move_pages(struct page *dst_page, struct page *src_page,
- unsigned long dst_off, unsigned long src_off,
- unsigned long len)
-{
- char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
- if (dst_page == src_page) {
- memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);
- } else {
- char *src_kaddr = kmap_atomic(src_page, KM_USER1);
- char *p = dst_kaddr + dst_off + len;
- char *s = src_kaddr + src_off + len;
-
- while (len--)
- *--p = *--s;
-
- kunmap_atomic(src_kaddr, KM_USER1);
- }
- kunmap_atomic(dst_kaddr, KM_USER0);
-}
-
-static void copy_pages(struct page *dst_page, struct page *src_page,
- unsigned long dst_off, unsigned long src_off,
- unsigned long len)
-{
- char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
- char *src_kaddr;
-
- if (dst_page != src_page)
- src_kaddr = kmap_atomic(src_page, KM_USER1);
- else
- src_kaddr = dst_kaddr;
-
- memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
- kunmap_atomic(dst_kaddr, KM_USER0);
- if (dst_page != src_page)
- kunmap_atomic(src_kaddr, KM_USER1);
-}
-
-void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
- unsigned long src_offset, unsigned long len)
-{
- size_t cur;
- size_t dst_off_in_page;
- size_t src_off_in_page;
- size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
- unsigned long dst_i;
- unsigned long src_i;
-
- if (src_offset + len > dst->len) {
- printk("memmove bogus src_offset %lu move len %lu len %lu\n",
- src_offset, len, dst->len);
- BUG_ON(1);
- }
- if (dst_offset + len > dst->len) {
- printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
- dst_offset, len, dst->len);
- BUG_ON(1);
- }
-
- while(len > 0) {
- dst_off_in_page = (start_offset + dst_offset) &
- ((unsigned long)PAGE_CACHE_SIZE - 1);
- src_off_in_page = (start_offset + src_offset) &
- ((unsigned long)PAGE_CACHE_SIZE - 1);
-
- dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;
- src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;
-
- cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -
- src_off_in_page));
- cur = min_t(unsigned long, cur,
- (unsigned long)(PAGE_CACHE_SIZE - dst_off_in_page));
-
- copy_pages(extent_buffer_page(dst, dst_i),
- extent_buffer_page(dst, src_i),
- dst_off_in_page, src_off_in_page, cur);
-
- src_offset += cur;
- dst_offset += cur;
- len -= cur;
- }
-}
-EXPORT_SYMBOL(memcpy_extent_buffer);
-
-void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
- unsigned long src_offset, unsigned long len)
-{
- size_t cur;
- size_t dst_off_in_page;
- size_t src_off_in_page;
- unsigned long dst_end = dst_offset + len - 1;
- unsigned long src_end = src_offset + len - 1;
- size_t start_offset = dst->start & ((u64)PAGE_CACHE_SIZE - 1);
- unsigned long dst_i;
- unsigned long src_i;
-
- if (src_offset + len > dst->len) {
- printk("memmove bogus src_offset %lu move len %lu len %lu\n",
- src_offset, len, dst->len);
- BUG_ON(1);
- }
- if (dst_offset + len > dst->len) {
- printk("memmove bogus dst_offset %lu move len %lu len %lu\n",
- dst_offset, len, dst->len);
- BUG_ON(1);
- }
- if (dst_offset < src_offset) {
- memcpy_extent_buffer(dst, dst_offset, src_offset, len);
- return;
- }
- while(len > 0) {
- dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;
- src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;
-
- dst_off_in_page = (start_offset + dst_end) &
- ((unsigned long)PAGE_CACHE_SIZE - 1);
- src_off_in_page = (start_offset + src_end) &
- ((unsigned long)PAGE_CACHE_SIZE - 1);
-
- cur = min_t(unsigned long, len, src_off_in_page + 1);
- cur = min(cur, dst_off_in_page + 1);
- move_pages(extent_buffer_page(dst, dst_i),
- extent_buffer_page(dst, src_i),
- dst_off_in_page - cur + 1,
- src_off_in_page - cur + 1, cur);
-
- dst_end -= cur;
- src_end -= cur;
- len -= cur;
- }
-}
-EXPORT_SYMBOL(memmove_extent_buffer);