Btrfs: make defragment work with nodatacow option
Btrfs defragment will utilize COW feature, which means this
did not work for nodatacow option, this problem was detected
by xfstests generic/018 with nodatacow mount option.
Fix this problem by forcing cow for a extent with state
@EXTETN_DEFRAG setting.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e326ffd..2370d72 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1445,6 +1445,26 @@
return ret;
}
+static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
+{
+
+ if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
+ !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
+ return 0;
+
+ /*
+ * @defrag_bytes is a hint value, no spinlock held here,
+ * if is not zero, it means the file is defragging.
+ * Force cow if given extent needs to be defragged.
+ */
+ if (BTRFS_I(inode)->defrag_bytes &&
+ test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
+ EXTENT_DEFRAG, 0, NULL))
+ return 1;
+
+ return 0;
+}
+
/*
* extent_io.c call back to do delayed allocation processing
*/
@@ -1454,11 +1474,12 @@
{
int ret;
struct btrfs_root *root = BTRFS_I(inode)->root;
+ int force_cow = need_force_cow(inode, start, end);
- if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
+ if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 1, nr_written);
- } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
+ } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 0, nr_written);
} else if (!btrfs_test_opt(root, COMPRESS) &&
@@ -1555,6 +1576,8 @@
struct extent_state *state, unsigned long *bits)
{
+ if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
+ WARN_ON(1);
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
@@ -1577,6 +1600,8 @@
root->fs_info->delalloc_batch);
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->delalloc_bytes += len;
+ if (*bits & EXTENT_DEFRAG)
+ BTRFS_I(inode)->defrag_bytes += len;
if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags))
btrfs_add_delalloc_inodes(root, inode);
@@ -1591,6 +1616,13 @@
struct extent_state *state,
unsigned long *bits)
{
+ u64 len = state->end + 1 - state->start;
+
+ spin_lock(&BTRFS_I(inode)->lock);
+ if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
+ BTRFS_I(inode)->defrag_bytes -= len;
+ spin_unlock(&BTRFS_I(inode)->lock);
+
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
@@ -1598,7 +1630,6 @@
*/
if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
- u64 len = state->end + 1 - state->start;
bool do_list = !btrfs_is_free_space_inode(inode);
if (*bits & EXTENT_FIRST_DELALLOC) {
@@ -8173,6 +8204,7 @@
ei->last_sub_trans = 0;
ei->logged_trans = 0;
ei->delalloc_bytes = 0;
+ ei->defrag_bytes = 0;
ei->disk_i_size = 0;
ei->flags = 0;
ei->csum_bytes = 0;
@@ -8231,6 +8263,7 @@
WARN_ON(BTRFS_I(inode)->reserved_extents);
WARN_ON(BTRFS_I(inode)->delalloc_bytes);
WARN_ON(BTRFS_I(inode)->csum_bytes);
+ WARN_ON(BTRFS_I(inode)->defrag_bytes);
/*
* This can happen where we create an inode, but somebody else also