btrfs: Support busy loop of write and delete
Reproduce:
while true; do
dd if=/dev/zero of=/mnt/btrfs/file count=[75% fs_size]
rm /mnt/btrfs/file
done
Then we can see above loop failed on NO_SPACE.
It it long-term problem since very beginning, because delayed-iput
after rm are not run.
We already have commit_transaction() in alloc_space code, but it is
not triggered in above case.
This patch trigger commit_transaction() to run delayed-iput and
reflash pinned-space to to make write success.
It is based on previous fix of delayed-iput in commit_transaction(),
need to be applied on top of:
btrfs: Fix NO_SPACE bug caused by delayed-iput
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 46cb1d41..2713dcb 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3858,14 +3858,14 @@
struct btrfs_fs_info *fs_info = root->fs_info;
u64 used;
int ret = 0;
- int committed = 0;
- int have_pinned_space = 1;
+ int need_commit = 2;
+ int have_pinned_space;
/* make sure bytes are sectorsize aligned */
bytes = ALIGN(bytes, root->sectorsize);
if (btrfs_is_free_space_inode(inode)) {
- committed = 1;
+ need_commit = 0;
ASSERT(current->journal_info);
}
@@ -3915,8 +3915,10 @@
if (ret < 0) {
if (ret != -ENOSPC)
return ret;
- else
+ else {
+ have_pinned_space = 1;
goto commit_trans;
+ }
}
if (!data_sinfo)
@@ -3930,23 +3932,23 @@
* allocation, and no removed chunk in current transaction,
* don't bother committing the transaction.
*/
- if (percpu_counter_compare(&data_sinfo->total_bytes_pinned,
- used + bytes -
- data_sinfo->total_bytes) < 0)
- have_pinned_space = 0;
+ have_pinned_space = percpu_counter_compare(
+ &data_sinfo->total_bytes_pinned,
+ used + bytes - data_sinfo->total_bytes);
spin_unlock(&data_sinfo->lock);
/* commit the current transaction and try again */
commit_trans:
- if (!committed &&
+ if (need_commit &&
!atomic_read(&root->fs_info->open_ioctl_trans)) {
- committed = 1;
+ need_commit--;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
- if (have_pinned_space ||
- trans->transaction->have_free_bgs) {
+ if (have_pinned_space >= 0 ||
+ trans->transaction->have_free_bgs ||
+ need_commit > 0) {
ret = btrfs_commit_transaction(trans, root);
if (ret)
return ret;