Btrfs: don't steal from the global reserve if we don't have the space
btrfs_evict_inode() needs to be more careful about stealing from the
global_rsv. We dont' want to end up aborting commit with ENOSPC just
because the evict_inode code was too greedy.
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 88537c5..141df0c 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5010,6 +5010,7 @@
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv, *global_rsv;
+ int steal_from_global = 0;
u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
int ret;
@@ -5077,9 +5078,20 @@
* hard as possible to get this to work.
*/
if (ret)
- ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
+ steal_from_global++;
+ else
+ steal_from_global = 0;
+ ret = 0;
- if (ret) {
+ /*
+ * steal_from_global == 0: we reserved stuff, hooray!
+ * steal_from_global == 1: we didn't reserve stuff, boo!
+ * steal_from_global == 2: we've committed, still not a lot of
+ * room but maybe we'll have room in the global reserve this
+ * time.
+ * steal_from_global == 3: abandon all hope!
+ */
+ if (steal_from_global > 2) {
btrfs_warn(root->fs_info,
"Could not get space for a delete, will truncate on mount %d",
ret);
@@ -5095,6 +5107,36 @@
goto no_delete;
}
+ /*
+ * We can't just steal from the global reserve, we need tomake
+ * sure there is room to do it, if not we need to commit and try
+ * again.
+ */
+ if (steal_from_global) {
+ if (!btrfs_check_space_for_delayed_refs(trans, root))
+ ret = btrfs_block_rsv_migrate(global_rsv, rsv,
+ min_size);
+ else
+ ret = -ENOSPC;
+ }
+
+ /*
+ * Couldn't steal from the global reserve, we have too much
+ * pending stuff built up, commit the transaction and try it
+ * again.
+ */
+ if (ret) {
+ ret = btrfs_commit_transaction(trans, root);
+ if (ret) {
+ btrfs_orphan_del(NULL, inode);
+ btrfs_free_block_rsv(root, rsv);
+ goto no_delete;
+ }
+ continue;
+ } else {
+ steal_from_global = 0;
+ }
+
trans->block_rsv = rsv;
ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);