@@ -127,6 +127,12 @@ struct btrfs_inode {
u64 delalloc_bytes;
/*
+ * total number of bytes pending defrag, used by stat to check whether
+ * it needs COW.
+ */
+ u64 defrag_bytes;
+
+ /*
* the size of the file stored in the metadata on disk. data=ordered
* means the in-memory i_size might be larger than the size on disk
* because not all the blocks are written yet.
@@ -1425,6 +1425,26 @@ error:
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
*/
@@ -1434,11 +1454,12 @@ static int run_delalloc_range(struct inode *inode, struct page *locked_page,
{
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) &&
@@ -1535,6 +1556,8 @@ static void btrfs_set_bit_hook(struct inode *inode,
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
@@ -1557,6 +1580,8 @@ static void btrfs_set_bit_hook(struct inode *inode,
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);
@@ -1571,6 +1596,13 @@ static void btrfs_clear_bit_hook(struct inode *inode,
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
@@ -1578,7 +1610,6 @@ static void btrfs_clear_bit_hook(struct inode *inode,
*/
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) {
@@ -8078,6 +8109,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
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;
@@ -8137,6 +8169,7 @@ void btrfs_destroy_inode(struct inode *inode)
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
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> --- fs/btrfs/btrfs_inode.h | 6 ++++++ fs/btrfs/inode.c | 39 ++++++++++++++++++++++++++++++++++++--- 2 files changed, 42 insertions(+), 3 deletions(-)