Btrfs: reduce stack in cow_file_range
The fs/btrfs/inode.c code to run delayed allocation during writout
needed some stack usage optimization. This is the first pass, it does
the check for compression earlier on, which allows us to do the common
(no compression) case higher up in the call chain.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 13a1747..c427011 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -204,7 +204,7 @@
* does the checks required to make sure the data is small enough
* to fit as an inline extent.
*/
-static int cow_file_range_inline(struct btrfs_trans_handle *trans,
+static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode, u64 start, u64 end,
size_t compressed_size,
@@ -854,11 +854,6 @@
u64 cur_end;
int limit = 10 * 1024 * 1042;
- if (!btrfs_test_opt(root, COMPRESS)) {
- return cow_file_range(inode, locked_page, start, end,
- page_started, nr_written, 1);
- }
-
clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED |
EXTENT_DELALLOC, 1, 0, GFP_NOFS);
while (start < end) {
@@ -935,7 +930,8 @@
* If no cow copies or snapshots exist, we write directly to the existing
* blocks on disk
*/
-static int run_delalloc_nocow(struct inode *inode, struct page *locked_page,
+static noinline int run_delalloc_nocow(struct inode *inode,
+ struct page *locked_page,
u64 start, u64 end, int *page_started, int force,
unsigned long *nr_written)
{
@@ -1133,6 +1129,7 @@
unsigned long *nr_written)
{
int ret;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
if (btrfs_test_flag(inode, NODATACOW))
ret = run_delalloc_nocow(inode, locked_page, start, end,
@@ -1140,10 +1137,12 @@
else if (btrfs_test_flag(inode, PREALLOC))
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 0, nr_written);
+ else if (!btrfs_test_opt(root, COMPRESS))
+ ret = cow_file_range(inode, locked_page, start, end,
+ page_started, nr_written, 1);
else
ret = cow_file_range_async(inode, locked_page, start, end,
page_started, nr_written);
-
return ret;
}