Btrfs: break up __btrfs_write_out_cache to cut down stack usage
__btrfs_write_out_cache was one of our stack pigs. This breaks it
up into helper functions and slims it down to 194 bytes.
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index a6bd654..372b05f 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -851,90 +851,44 @@
return ret;
}
-/**
- * __btrfs_write_out_cache - write out cached info to an inode
- * @root - the root the inode belongs to
- * @ctl - the free space cache we are going to write out
- * @block_group - the block_group for this cache if it belongs to a block_group
- * @trans - the trans handle
- * @path - the path to use
- * @offset - the offset for the key we'll insert
- *
- * This function writes out a free space cache struct to disk for quick recovery
- * on mount. This will return 0 if it was successfull in writing the cache out,
- * and -1 if it was not.
- */
-static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
- struct btrfs_free_space_ctl *ctl,
- struct btrfs_block_group_cache *block_group,
- struct btrfs_trans_handle *trans,
- struct btrfs_path *path, u64 offset)
+static noinline_for_stack
+int write_cache_extent_entries(struct io_ctl *io_ctl,
+ struct btrfs_free_space_ctl *ctl,
+ struct btrfs_block_group_cache *block_group,
+ int *entries, int *bitmaps,
+ struct list_head *bitmap_list)
{
- struct btrfs_free_space_header *header;
- struct extent_buffer *leaf;
- struct rb_node *node;
- struct list_head *pos, *n;
- struct extent_state *cached_state = NULL;
- struct btrfs_free_cluster *cluster = NULL;
- struct extent_io_tree *unpin = NULL;
- struct io_ctl io_ctl;
- struct list_head bitmap_list;
- struct btrfs_key key;
- u64 start, extent_start, extent_end, len;
- int entries = 0;
- int bitmaps = 0;
int ret;
- int err = -1;
-
- INIT_LIST_HEAD(&bitmap_list);
-
- if (!i_size_read(inode))
- return -1;
-
- ret = io_ctl_init(&io_ctl, inode, root);
- if (ret)
- return -1;
+ struct btrfs_free_cluster *cluster = NULL;
+ struct rb_node *node = rb_first(&ctl->free_space_offset);
/* Get the cluster for this block_group if it exists */
- if (block_group && !list_empty(&block_group->cluster_list))
+ if (block_group && !list_empty(&block_group->cluster_list)) {
cluster = list_entry(block_group->cluster_list.next,
struct btrfs_free_cluster,
block_group_list);
+ }
- /* Lock all pages first so we can lock the extent safely. */
- io_ctl_prepare_pages(&io_ctl, inode, 0);
-
- lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
- 0, &cached_state);
-
- node = rb_first(&ctl->free_space_offset);
if (!node && cluster) {
node = rb_first(&cluster->root);
cluster = NULL;
}
- /* Make sure we can fit our crcs into the first page */
- if (io_ctl.check_crcs &&
- (io_ctl.num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE)
- goto out_nospc;
-
- io_ctl_set_generation(&io_ctl, trans->transid);
-
/* Write out the extent entries */
while (node) {
struct btrfs_free_space *e;
e = rb_entry(node, struct btrfs_free_space, offset_index);
- entries++;
+ *entries += 1;
- ret = io_ctl_add_entry(&io_ctl, e->offset, e->bytes,
+ ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
e->bitmap);
if (ret)
- goto out_nospc;
+ goto fail;
if (e->bitmap) {
- list_add_tail(&e->list, &bitmap_list);
- bitmaps++;
+ list_add_tail(&e->list, bitmap_list);
+ *bitmaps += 1;
}
node = rb_next(node);
if (!node && cluster) {
@@ -942,13 +896,84 @@
cluster = NULL;
}
}
+ return 0;
+fail:
+ return -ENOSPC;
+}
+
+static noinline_for_stack int
+update_cache_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode,
+ struct btrfs_path *path, u64 offset,
+ int entries, int bitmaps)
+{
+ struct btrfs_key key;
+ struct btrfs_free_space_header *header;
+ struct extent_buffer *leaf;
+ int ret;
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = offset;
+ key.type = 0;
+
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0) {
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
+ EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
+ GFP_NOFS);
+ goto fail;
+ }
+ leaf = path->nodes[0];
+ if (ret > 0) {
+ struct btrfs_key found_key;
+ ASSERT(path->slots[0]);
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
+ found_key.offset != offset) {
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
+ inode->i_size - 1,
+ EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
+ NULL, GFP_NOFS);
+ btrfs_release_path(path);
+ goto fail;
+ }
+ }
+
+ BTRFS_I(inode)->generation = trans->transid;
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ btrfs_set_free_space_entries(leaf, header, entries);
+ btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
+ btrfs_set_free_space_generation(leaf, header, trans->transid);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(path);
+
+ return 0;
+
+fail:
+ return -1;
+}
+
+static noinline_for_stack int
+add_ioctl_entries(struct btrfs_root *root,
+ struct inode *inode,
+ struct btrfs_block_group_cache *block_group,
+ struct io_ctl *io_ctl,
+ struct extent_state **cached_state,
+ struct list_head *bitmap_list,
+ int *entries)
+{
+ u64 start, extent_start, extent_end, len;
+ struct list_head *pos, *n;
+ struct extent_io_tree *unpin = NULL;
+ int ret;
/*
* We want to add any pinned extents to our free space cache
* so we don't leak the space
- */
-
- /*
+ *
* We shouldn't have switched the pinned extents yet so this is the
* right one
*/
@@ -977,8 +1002,8 @@
block_group->key.offset, extent_end + 1);
len = extent_end - extent_start;
- entries++;
- ret = io_ctl_add_entry(&io_ctl, extent_start, len, NULL);
+ *entries += 1;
+ ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
if (ret)
goto out_nospc;
@@ -986,74 +1011,129 @@
}
/* Write out the bitmaps */
- list_for_each_safe(pos, n, &bitmap_list) {
+ list_for_each_safe(pos, n, bitmap_list) {
struct btrfs_free_space *entry =
list_entry(pos, struct btrfs_free_space, list);
- ret = io_ctl_add_bitmap(&io_ctl, entry->bitmap);
+ ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
if (ret)
goto out_nospc;
list_del_init(&entry->list);
}
/* Zero out the rest of the pages just to make sure */
- io_ctl_zero_remaining_pages(&io_ctl);
+ io_ctl_zero_remaining_pages(io_ctl);
- ret = btrfs_dirty_pages(root, inode, io_ctl.pages, io_ctl.num_pages,
- 0, i_size_read(inode), &cached_state);
- io_ctl_drop_pages(&io_ctl);
+ ret = btrfs_dirty_pages(root, inode, io_ctl->pages, io_ctl->num_pages,
+ 0, i_size_read(inode), cached_state);
+ io_ctl_drop_pages(io_ctl);
unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
- i_size_read(inode) - 1, &cached_state, GFP_NOFS);
+ i_size_read(inode) - 1, cached_state, GFP_NOFS);
if (ret)
- goto out;
+ goto fail;
ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
if (ret) {
clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
GFP_NOFS);
+ goto fail;
+ }
+ return 0;
+
+fail:
+ return -1;
+
+out_nospc:
+ return -ENOSPC;
+}
+
+static void noinline_for_stack
+cleanup_write_cache_enospc(struct inode *inode,
+ struct io_ctl *io_ctl,
+ struct extent_state **cached_state,
+ struct list_head *bitmap_list)
+{
+ struct list_head *pos, *n;
+ list_for_each_safe(pos, n, bitmap_list) {
+ struct btrfs_free_space *entry =
+ list_entry(pos, struct btrfs_free_space, list);
+ list_del_init(&entry->list);
+ }
+ io_ctl_drop_pages(io_ctl);
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
+ i_size_read(inode) - 1, cached_state,
+ GFP_NOFS);
+}
+
+/**
+ * __btrfs_write_out_cache - write out cached info to an inode
+ * @root - the root the inode belongs to
+ * @ctl - the free space cache we are going to write out
+ * @block_group - the block_group for this cache if it belongs to a block_group
+ * @trans - the trans handle
+ * @path - the path to use
+ * @offset - the offset for the key we'll insert
+ *
+ * This function writes out a free space cache struct to disk for quick recovery
+ * on mount. This will return 0 if it was successfull in writing the cache out,
+ * and -1 if it was not.
+ */
+static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
+ struct btrfs_free_space_ctl *ctl,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path, u64 offset)
+{
+ struct extent_state *cached_state = NULL;
+ struct io_ctl io_ctl;
+ struct list_head bitmap_list;
+ int entries = 0;
+ int bitmaps = 0;
+ int ret;
+ int err = -1;
+
+ INIT_LIST_HEAD(&bitmap_list);
+
+ if (!i_size_read(inode))
+ return -1;
+
+ ret = io_ctl_init(&io_ctl, inode, root);
+ if (ret)
+ return -1;
+
+ /* Lock all pages first so we can lock the extent safely. */
+ io_ctl_prepare_pages(&io_ctl, inode, 0);
+
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
+ 0, &cached_state);
+
+
+ /* Make sure we can fit our crcs into the first page */
+ if (io_ctl.check_crcs &&
+ (io_ctl.num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE)
+ goto out_nospc;
+
+ io_ctl_set_generation(&io_ctl, trans->transid);
+
+ ret = write_cache_extent_entries(&io_ctl, ctl,
+ block_group, &entries, &bitmaps,
+ &bitmap_list);
+ if (ret)
+ goto out_nospc;
+
+ ret = add_ioctl_entries(root, inode, block_group, &io_ctl,
+ &cached_state, &bitmap_list, &entries);
+
+ if (ret == -ENOSPC)
+ goto out_nospc;
+ else if (ret)
goto out;
- }
- key.objectid = BTRFS_FREE_SPACE_OBJECTID;
- key.offset = offset;
- key.type = 0;
+ err = update_cache_item(trans, root, inode, path, offset,
+ entries, bitmaps);
- ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
- if (ret < 0) {
- clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
- EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
- GFP_NOFS);
- goto out;
- }
- leaf = path->nodes[0];
- if (ret > 0) {
- struct btrfs_key found_key;
- ASSERT(path->slots[0]);
- path->slots[0]--;
- btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
- if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
- found_key.offset != offset) {
- clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
- inode->i_size - 1,
- EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
- NULL, GFP_NOFS);
- btrfs_release_path(path);
- goto out;
- }
- }
-
- BTRFS_I(inode)->generation = trans->transid;
- header = btrfs_item_ptr(leaf, path->slots[0],
- struct btrfs_free_space_header);
- btrfs_set_free_space_entries(leaf, header, entries);
- btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
- btrfs_set_free_space_generation(leaf, header, trans->transid);
- btrfs_mark_buffer_dirty(leaf);
- btrfs_release_path(path);
-
- err = 0;
out:
io_ctl_free(&io_ctl);
if (err) {
@@ -1064,14 +1144,8 @@
return err;
out_nospc:
- list_for_each_safe(pos, n, &bitmap_list) {
- struct btrfs_free_space *entry =
- list_entry(pos, struct btrfs_free_space, list);
- list_del_init(&entry->list);
- }
- io_ctl_drop_pages(&io_ctl);
- unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
- i_size_read(inode) - 1, &cached_state, GFP_NOFS);
+
+ cleanup_write_cache_enospc(inode, &io_ctl, &cached_state, &bitmap_list);
goto out;
}