Btrfs: check if we can nocow if we don't have data space
We always just try and reserve data space when we write, but if we are out of
space but have prealloc'ed extents we should still successfully write. This
patch will try and see if we can write to prealloc'ed space and if we can go
ahead and allow the write to continue. With this patch we now pass xfstests
generic/274. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b528a55..e795bf1 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3552,6 +3552,10 @@
struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
size_t pg_offset, u64 start, u64 len,
int create);
+noinline int can_nocow_extent(struct btrfs_trans_handle *trans,
+ struct inode *inode, u64 offset, u64 *len,
+ u64 *orig_start, u64 *orig_block_len,
+ u64 *ram_bytes);
/* RHEL and EL kernels have a patch that renames PG_checked to FsMisc */
#if defined(ClearPageFsMisc) && !defined(ClearPageChecked)