struct address_space *mapping, gfp_t mask)
{
tree->state = RB_ROOT;
- tree->buffer = RB_ROOT;
+ INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
tree->ops = NULL;
tree->dirty_bytes = 0;
spin_lock_init(&tree->lock);
return ret;
}
-static struct extent_buffer *buffer_tree_insert(struct extent_io_tree *tree,
- u64 offset, struct rb_node *node)
-{
- struct rb_root *root = &tree->buffer;
- struct rb_node **p = &root->rb_node;
- struct rb_node *parent = NULL;
- struct extent_buffer *eb;
-
- while (*p) {
- parent = *p;
- eb = rb_entry(parent, struct extent_buffer, rb_node);
-
- if (offset < eb->start)
- p = &(*p)->rb_left;
- else if (offset > eb->start)
- p = &(*p)->rb_right;
- else
- return eb;
- }
-
- rb_link_node(node, parent, p);
- rb_insert_color(node, root);
- return NULL;
-}
-
-static struct extent_buffer *buffer_search(struct extent_io_tree *tree,
- u64 offset)
-{
- struct rb_root *root = &tree->buffer;
- struct rb_node *n = root->rb_node;
- struct extent_buffer *eb;
-
- while (n) {
- eb = rb_entry(n, struct extent_buffer, rb_node);
- if (offset < eb->start)
- n = n->rb_left;
- else if (offset > eb->start)
- n = n->rb_right;
- else
- return eb;
- }
- return NULL;
-}
-
static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
struct extent_state *other)
{
bio_put(bio);
}
-static struct bio *
-extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
- gfp_t gfp_flags)
+struct bio *
+btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
+ gfp_t gfp_flags)
{
struct bio *bio;
struct page *page = bvec->bv_page;
struct extent_io_tree *tree = bio->bi_private;
u64 start;
- u64 end;
start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
- end = start + bvec->bv_len - 1;
bio->bi_private = NULL;
bio_get(bio);
if (tree->ops && tree->ops->submit_bio_hook)
- tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
+ ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
mirror_num, bio_flags, start);
else
submit_bio(rw, bio);
else
nr = bio_get_nr_vecs(bdev);
- bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
+ bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
+ if (!bio)
+ return -ENOMEM;
bio_add_page(bio, page, page_size, offset);
bio->bi_end_io = end_io_func;
static void set_page_extent_head(struct page *page, unsigned long len)
{
+ WARN_ON(!PagePrivate(page));
set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2);
}
BUG_ON(extent_map_end(em) <= cur);
BUG_ON(end < cur);
- if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
+ if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
this_bio_flag = EXTENT_BIO_COMPRESSED;
+ extent_set_compress_type(&this_bio_flag,
+ em->compress_type);
+ }
iosize = min(extent_map_end(em) - cur, end - cur + 1);
cur_end = min(extent_map_end(em) - 1, end);
ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
&bio_flags);
if (bio)
- submit_one_bio(READ, bio, 0, bio_flags);
+ ret = submit_one_bio(READ, bio, 0, bio_flags);
return ret;
}
u64 last_byte = i_size_read(inode);
u64 block_start;
u64 iosize;
- u64 unlock_start;
sector_t sector;
struct extent_state *cached_state = NULL;
struct extent_map *em;
if (tree->ops && tree->ops->writepage_end_io_hook)
tree->ops->writepage_end_io_hook(page, start,
page_end, NULL, 1);
- unlock_start = page_end + 1;
goto done;
}
if (tree->ops && tree->ops->writepage_end_io_hook)
tree->ops->writepage_end_io_hook(page, cur,
page_end, NULL, 1);
- unlock_start = page_end + 1;
break;
}
em = epd->get_extent(inode, page, pg_offset, cur,
cur += iosize;
pg_offset += iosize;
- unlock_start = cur;
continue;
}
/* leave this out until we have a page_mkwrite call */
pgoff_t index;
pgoff_t end; /* Inclusive */
int scanned = 0;
- int range_whole = 0;
pagevec_init(&pvec, 0);
if (wbc->range_cyclic) {
} 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:
NULL, 1,
end_bio_extent_preparewrite, 0,
0, 0);
+ if (ret && !err)
+ err = ret;
iocount++;
block_start = block_start + iosize;
} else {
* at this point we can safely clear everything except the
* locked bit and the nodatasum bit
*/
- clear_extent_bit(tree, start, end,
+ ret = clear_extent_bit(tree, start, end,
~(EXTENT_LOCKED | EXTENT_NODATASUM),
0, 0, NULL, mask);
+
+ /* if clear_extent_bit failed for enomem reasons,
+ * we can't allow the release to continue.
+ */
+ if (ret < 0)
+ ret = 0;
+ else
+ ret = 1;
}
return ret;
}
int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len, get_extent_t *get_extent)
{
- int ret;
+ int ret = 0;
u64 off = start;
u64 max = start + len;
u32 flags = 0;
+ u32 found_type;
+ u64 last;
u64 disko = 0;
+ struct btrfs_key found_key;
struct extent_map *em = NULL;
struct extent_state *cached_state = NULL;
+ struct btrfs_path *path;
+ struct btrfs_file_extent_item *item;
int end = 0;
u64 em_start = 0, em_len = 0;
unsigned long emflags;
- ret = 0;
+ int hole = 0;
if (len == 0)
return -EINVAL;
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ path->leave_spinning = 1;
+
+ ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
+ path, inode->i_ino, -1, 0);
+ if (ret < 0) {
+ btrfs_free_path(path);
+ return ret;
+ }
+ WARN_ON(!ret);
+ path->slots[0]--;
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
+ found_type = btrfs_key_type(&found_key);
+
+ /* No extents, just return */
+ if (found_key.objectid != inode->i_ino ||
+ found_type != BTRFS_EXTENT_DATA_KEY) {
+ btrfs_free_path(path);
+ return 0;
+ }
+ last = found_key.offset;
+ btrfs_free_path(path);
+
lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
&cached_state, GFP_NOFS);
em = get_extent(inode, NULL, 0, off, max - off, 0);
ret = PTR_ERR(em);
goto out;
}
+
while (!end) {
+ hole = 0;
off = em->start + em->len;
if (off >= max)
end = 1;
+ if (em->block_start == EXTENT_MAP_HOLE) {
+ hole = 1;
+ goto next;
+ }
+
em_start = em->start;
em_len = em->len;
if (em->block_start == EXTENT_MAP_LAST_BYTE) {
end = 1;
flags |= FIEMAP_EXTENT_LAST;
- } else if (em->block_start == EXTENT_MAP_HOLE) {
- flags |= FIEMAP_EXTENT_UNWRITTEN;
} else if (em->block_start == EXTENT_MAP_INLINE) {
flags |= (FIEMAP_EXTENT_DATA_INLINE |
FIEMAP_EXTENT_NOT_ALIGNED);
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
flags |= FIEMAP_EXTENT_ENCODED;
+next:
emflags = em->flags;
free_extent_map(em);
em = NULL;
-
if (!end) {
em = get_extent(inode, NULL, 0, off, max - off, 0);
if (!em)
}
emflags = em->flags;
}
+
if (test_bit(EXTENT_FLAG_VACANCY, &emflags)) {
flags |= FIEMAP_EXTENT_LAST;
end = 1;
}
- ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
- em_len, flags);
- if (ret)
- goto out_free;
+ if (em_start == last) {
+ flags |= FIEMAP_EXTENT_LAST;
+ end = 1;
+ }
+
+ if (!hole) {
+ ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
+ em_len, flags);
+ if (ret)
+ goto out_free;
+ }
}
out_free:
free_extent_map(em);
#endif
eb = kmem_cache_zalloc(extent_buffer_cache, mask);
+ if (eb == NULL)
+ return NULL;
eb->start = start;
eb->len = len;
spin_lock_init(&eb->lock);
init_waitqueue_head(&eb->lock_wq);
+ INIT_RCU_HEAD(&eb->rcu_head);
#if LEAK_DEBUG
spin_lock_irqsave(&leak_lock, flags);
kmem_cache_free(extent_buffer_cache, eb);
}
+/*
+ * Helper for releasing extent buffer page.
+ */
+static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
+ unsigned long start_idx)
+{
+ unsigned long index;
+ struct page *page;
+
+ if (!eb->first_page)
+ return;
+
+ index = num_extent_pages(eb->start, eb->len);
+ if (start_idx >= index)
+ return;
+
+ do {
+ index--;
+ page = extent_buffer_page(eb, index);
+ if (page)
+ page_cache_release(page);
+ } while (index != start_idx);
+}
+
+/*
+ * Helper for releasing the extent buffer.
+ */
+static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
+{
+ btrfs_release_extent_buffer_page(eb, 0);
+ __free_extent_buffer(eb);
+}
+
struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
u64 start, unsigned long len,
struct page *page0,
struct page *p;
struct address_space *mapping = tree->mapping;
int uptodate = 1;
+ int ret;
- spin_lock(&tree->buffer_lock);
- eb = buffer_search(tree, start);
- if (eb) {
- atomic_inc(&eb->refs);
- spin_unlock(&tree->buffer_lock);
+ rcu_read_lock();
+ eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
+ if (eb && atomic_inc_not_zero(&eb->refs)) {
+ rcu_read_unlock();
mark_page_accessed(eb->first_page);
return eb;
}
- spin_unlock(&tree->buffer_lock);
+ rcu_read_unlock();
eb = __alloc_extent_buffer(tree, start, len, mask);
if (!eb)
}
if (!PageUptodate(p))
uptodate = 0;
- unlock_page(p);
+
+ /*
+ * see below about how we avoid a nasty race with release page
+ * and why we unlock later
+ */
+ if (i != 0)
+ unlock_page(p);
}
if (uptodate)
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
+ ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
+ if (ret)
+ goto free_eb;
+
spin_lock(&tree->buffer_lock);
- exists = buffer_tree_insert(tree, start, &eb->rb_node);
- if (exists) {
+ ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
+ if (ret == -EEXIST) {
+ exists = radix_tree_lookup(&tree->buffer,
+ start >> PAGE_CACHE_SHIFT);
/* add one reference for the caller */
atomic_inc(&exists->refs);
spin_unlock(&tree->buffer_lock);
+ radix_tree_preload_end();
goto free_eb;
}
/* add one reference for the tree */
atomic_inc(&eb->refs);
spin_unlock(&tree->buffer_lock);
+ radix_tree_preload_end();
+
+ /*
+ * there is a race where release page may have
+ * tried to find this extent buffer in the radix
+ * but failed. It will tell the VM it is safe to
+ * reclaim the, and it will clear the page private bit.
+ * We must make sure to set the page private bit properly
+ * after the extent buffer is in the radix tree so
+ * it doesn't get lost
+ */
+ set_page_extent_mapped(eb->first_page);
+ set_page_extent_head(eb->first_page, eb->len);
+ if (!page0)
+ unlock_page(eb->first_page);
return eb;
free_eb:
+ if (eb->first_page && !page0)
+ unlock_page(eb->first_page);
+
if (!atomic_dec_and_test(&eb->refs))
return exists;
- for (index = 1; index < i; index++)
- page_cache_release(extent_buffer_page(eb, index));
- page_cache_release(extent_buffer_page(eb, 0));
- __free_extent_buffer(eb);
+ btrfs_release_extent_buffer(eb);
return exists;
}
{
struct extent_buffer *eb;
- spin_lock(&tree->buffer_lock);
- eb = buffer_search(tree, start);
- if (eb)
- atomic_inc(&eb->refs);
- spin_unlock(&tree->buffer_lock);
-
- if (eb)
+ rcu_read_lock();
+ eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
+ if (eb && atomic_inc_not_zero(&eb->refs)) {
+ rcu_read_unlock();
mark_page_accessed(eb->first_page);
+ return eb;
+ }
+ rcu_read_unlock();
- return eb;
+ return NULL;
}
void free_extent_buffer(struct extent_buffer *eb)
continue;
lock_page(page);
+ WARN_ON(!PagePrivate(page));
+
+ set_page_extent_mapped(page);
if (i == 0)
set_page_extent_head(page, eb->len);
- else
- set_page_private(page, EXTENT_PAGE_PRIVATE);
clear_page_dirty_for_io(page);
spin_lock_irq(&page->mapping->tree_lock);
for (i = start_i; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
+
+ WARN_ON(!PagePrivate(page));
+
+ set_page_extent_mapped(page);
+ if (i == 0)
+ set_page_extent_head(page, eb->len);
+
if (inc_all_pages)
page_cache_get(page);
if (!PageUptodate(page)) {
}
}
+static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
+{
+ struct extent_buffer *eb =
+ container_of(head, struct extent_buffer, rcu_head);
+
+ btrfs_release_extent_buffer(eb);
+}
+
int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
{
u64 start = page_offset(page);
struct extent_buffer *eb;
int ret = 1;
- unsigned long i;
- unsigned long num_pages;
spin_lock(&tree->buffer_lock);
- eb = buffer_search(tree, start);
- if (!eb)
- goto out;
+ eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
+ if (!eb) {
+ spin_unlock(&tree->buffer_lock);
+ return ret;
+ }
- if (atomic_read(&eb->refs) > 1) {
+ if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
ret = 0;
goto out;
}
- if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
+
+ /*
+ * set @eb->refs to 0 if it is already 1, and then release the @eb.
+ * Or go back.
+ */
+ if (atomic_cmpxchg(&eb->refs, 1, 0) != 1) {
ret = 0;
goto out;
}
- /* at this point we can safely release the extent buffer */
- num_pages = num_extent_pages(eb->start, eb->len);
- for (i = 0; i < num_pages; i++)
- page_cache_release(extent_buffer_page(eb, i));
- rb_erase(&eb->rb_node, &tree->buffer);
- __free_extent_buffer(eb);
+
+ radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT);
out:
spin_unlock(&tree->buffer_lock);
+
+ /* at this point we can safely release the extent buffer */
+ if (atomic_read(&eb->refs) == 0)
+ call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
return ret;
}
git.openpandora.org / pandora-kernel.git / blobdiff