summaryrefslogtreecommitdiffstats
path: root/fs/btrfs/delayed-inode.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/btrfs/delayed-inode.c')
-rw-r--r--fs/btrfs/delayed-inode.c62
1 files changed, 59 insertions, 3 deletions
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 3a1b939c9ae2..9c1eccc2c503 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -617,12 +617,14 @@ static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
static int btrfs_delayed_inode_reserve_metadata(
struct btrfs_trans_handle *trans,
struct btrfs_root *root,
+ struct inode *inode,
struct btrfs_delayed_node *node)
{
struct btrfs_block_rsv *src_rsv;
struct btrfs_block_rsv *dst_rsv;
u64 num_bytes;
int ret;
+ int release = false;
src_rsv = trans->block_rsv;
dst_rsv = &root->fs_info->delayed_block_rsv;
@@ -638,8 +640,8 @@ static int btrfs_delayed_inode_reserve_metadata(
* Now if src_rsv == delalloc_block_rsv we'll let it just steal since
* we're accounted for.
*/
- if (!trans->bytes_reserved &&
- src_rsv != &root->fs_info->delalloc_block_rsv) {
+ if (!src_rsv || (!trans->bytes_reserved &&
+ src_rsv != &root->fs_info->delalloc_block_rsv)) {
ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
/*
* Since we're under a transaction reserve_metadata_bytes could
@@ -652,12 +654,65 @@ static int btrfs_delayed_inode_reserve_metadata(
if (!ret)
node->bytes_reserved = num_bytes;
return ret;
+ } else if (src_rsv == &root->fs_info->delalloc_block_rsv) {
+ spin_lock(&BTRFS_I(inode)->lock);
+ if (BTRFS_I(inode)->delalloc_meta_reserved) {
+ BTRFS_I(inode)->delalloc_meta_reserved = 0;
+ spin_unlock(&BTRFS_I(inode)->lock);
+ release = true;
+ goto migrate;
+ }
+ spin_unlock(&BTRFS_I(inode)->lock);
+
+ /* Ok we didn't have space pre-reserved. This shouldn't happen
+ * too often but it can happen if we do delalloc to an existing
+ * inode which gets dirtied because of the time update, and then
+ * isn't touched again until after the transaction commits and
+ * then we try to write out the data. First try to be nice and
+ * reserve something strictly for us. If not be a pain and try
+ * to steal from the delalloc block rsv.
+ */
+ ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
+ if (!ret)
+ goto out;
+
+ ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
+ if (!ret)
+ goto out;
+
+ /*
+ * Ok this is a problem, let's just steal from the global rsv
+ * since this really shouldn't happen that often.
+ */
+ WARN_ON(1);
+ ret = btrfs_block_rsv_migrate(&root->fs_info->global_block_rsv,
+ dst_rsv, num_bytes);
+ goto out;
}
+migrate:
ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
+
+out:
+ /*
+ * Migrate only takes a reservation, it doesn't touch the size of the
+ * block_rsv. This is to simplify people who don't normally have things
+ * migrated from their block rsv. If they go to release their
+ * reservation, that will decrease the size as well, so if migrate
+ * reduced size we'd end up with a negative size. But for the
+ * delalloc_meta_reserved stuff we will only know to drop 1 reservation,
+ * but we could in fact do this reserve/migrate dance several times
+ * between the time we did the original reservation and we'd clean it
+ * up. So to take care of this, release the space for the meta
+ * reservation here. I think it may be time for a documentation page on
+ * how block rsvs. work.
+ */
if (!ret)
node->bytes_reserved = num_bytes;
+ if (release)
+ btrfs_block_rsv_release(root, src_rsv, num_bytes);
+
return ret;
}
@@ -1708,7 +1763,8 @@ int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
goto release_node;
}
- ret = btrfs_delayed_inode_reserve_metadata(trans, root, delayed_node);
+ ret = btrfs_delayed_inode_reserve_metadata(trans, root, inode,
+ delayed_node);
if (ret)
goto release_node;