From: Omar Sandoval <osan...@fb.com>
The truncate loop in btrfs_evict_inode() does two things at once:
- It refills the temporary block reserve, potentially stealing from the
global reserve or committing
- It calls btrfs_truncate_inode_items()
The tangle of continues hides the fact that these two steps are actually
separate. Split the first step out into a separate function both for
clarity and so that we can reuse it in a later patch.
Reviewed-by: Nikolay Borisov <nbori...@suse.com>
Signed-off-by: Omar Sandoval <osan...@fb.com>
---
fs/btrfs/inode.c | 113 ++++++++++++++++++-----------------------------
1 file changed, 42 insertions(+), 71 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index ad4b7fb62f46..0a753f3a3321 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5189,13 +5189,52 @@ static void evict_inode_truncate_pages(struct inode
*inode)
spin_unlock(&io_tree->lock);
}
+static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root
*root,
+ struct btrfs_block_rsv
*rsv,
+ u64 min_size)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+ int failures = 0;
+
+ for (;;) {
+ struct btrfs_trans_handle *trans;
+ int ret;
+
+ ret = btrfs_block_rsv_refill(root, rsv, min_size,
+ BTRFS_RESERVE_FLUSH_LIMIT);
+
+ if (ret && ++failures > 2) {
+ btrfs_warn(fs_info,
+ "could not allocate space for a delete; will
truncate on mount");
+ return ERR_PTR(-ENOSPC);
+ }
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans) || !ret)
+ return trans;
+
+ /*
+ * Try to steal from the global reserve if there is space for
+ * it.
+ */
+ if (!btrfs_check_space_for_delayed_refs(trans, fs_info) &&
+ !btrfs_block_rsv_migrate(global_rsv, rsv, min_size, 0))
+ return trans;
+
+ /* If not, commit and try again. */
+ ret = btrfs_commit_transaction(trans);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+}
+
void btrfs_evict_inode(struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
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;
+ struct btrfs_block_rsv *rsv;
u64 min_size;
int ret;
@@ -5248,85 +5287,17 @@ void btrfs_evict_inode(struct inode *inode)
}
rsv->size = min_size;
rsv->failfast = 1;
- global_rsv = &fs_info->global_block_rsv;
btrfs_i_size_write(BTRFS_I(inode), 0);
- /*
- * This is a bit simpler than btrfs_truncate since we've already
- * reserved our space for our orphan item in the unlink, so we just
- * need to reserve some slack space in case we add bytes and update
- * inode item when doing the truncate.
- */
while (1) {
- ret = btrfs_block_rsv_refill(root, rsv, min_size,
- BTRFS_RESERVE_FLUSH_LIMIT);
-
- /*
- * Try and steal from the global reserve since we will
- * likely not use this space anyway, we want to try as
- * hard as possible to get this to work.
- */
- if (ret)
- steal_from_global++;
- else
- steal_from_global = 0;
- ret = 0;
-
- /*
- * 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(fs_info,
- "Could not get space for a delete, will
truncate on mount %d",
- ret);
- btrfs_orphan_del(NULL, BTRFS_I(inode));
- btrfs_free_block_rsv(fs_info, rsv);
- goto no_delete;
- }
-
- trans = btrfs_join_transaction(root);
+ trans = evict_refill_and_join(root, rsv, min_size);
if (IS_ERR(trans)) {
btrfs_orphan_del(NULL, BTRFS_I(inode));
btrfs_free_block_rsv(fs_info, rsv);
goto no_delete;
}
- /*
- * We can't just steal from the global reserve, we need to make
- * 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, fs_info))
- ret = btrfs_block_rsv_migrate(global_rsv, rsv,
- min_size, 0);
- 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);
- if (ret) {
- btrfs_orphan_del(NULL, BTRFS_I(inode));
- btrfs_free_block_rsv(fs_info, rsv);
- goto no_delete;
- }
- continue;
- } else {
- steal_from_global = 0;
- }
-
trans->block_rsv = rsv;
ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
--
2.17.0
--
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