From 3503895788d402d6a3814085ed582c364ec3e903 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Tue, 31 Oct 2023 12:02:06 -0400 Subject: virtio_pci: move structure to a header These are guest/host interfaces, so they belong in the header where e.g. qemu will know to find them. Note: we added a new structure as opposed to extending existing one because someone might be relying on the size of the existing structure staying unchanged. Add a warning to avoid using sizeof. Signed-off-by: Michael S. Tsirkin Reviewed-by: Xuan Zhuo --- include/uapi/linux/virtio_pci.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h index f703afc7ad31..44f4dd2add18 100644 --- a/include/uapi/linux/virtio_pci.h +++ b/include/uapi/linux/virtio_pci.h @@ -166,6 +166,17 @@ struct virtio_pci_common_cfg { __le32 queue_used_hi; /* read-write */ }; +/* + * Warning: do not use sizeof on this: use offsetofend for + * specific fields you need. + */ +struct virtio_pci_modern_common_cfg { + struct virtio_pci_common_cfg cfg; + + __le16 queue_notify_data; /* read-write */ + __le16 queue_reset; /* read-write */ +}; + /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */ struct virtio_pci_cfg_cap { struct virtio_pci_cap cap; -- cgit From d3933152442b7f94419e9ea71835d71b620baf0e Mon Sep 17 00:00:00 2001 From: Boris Burkov Date: Fri, 3 Nov 2023 11:38:04 -0700 Subject: btrfs: make OWNER_REF_KEY type value smallest among inline refs BTRFS_EXTENT_OWNER_REF_KEY is the type of simple quotas extent owner refs. This special inline ref goes in front of all other inline refs. In general, inline refs have a required sorted order s.t. type never decreases (among other requirements). This was recently reified into a tree-checker and fsck rule, which broke simple quotas. To be fair, though, in a sense, the new owner ref item had also violated that not yet fully enforced requirement. This fix brings the owner ref item into compliance with the requirement that inline ref type never decrease. btrfs/301 exercises this behavior and should pass again with this fix. Fixes: d9a620f77e33 ("btrfs: new inline ref storing owning subvol of data extents") Signed-off-by: Boris Burkov Reviewed-by: David Sterba Signed-off-by: David Sterba --- include/uapi/linux/btrfs_tree.h | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h index c25fc9614594..d24e8e121507 100644 --- a/include/uapi/linux/btrfs_tree.h +++ b/include/uapi/linux/btrfs_tree.h @@ -219,6 +219,22 @@ */ #define BTRFS_METADATA_ITEM_KEY 169 +/* + * Special inline ref key which stores the id of the subvolume which originally + * created the extent. This subvolume owns the extent permanently from the + * perspective of simple quotas. Needed to know which subvolume to free quota + * usage from when the extent is deleted. + * + * Stored as an inline ref rather to avoid wasting space on a separate item on + * top of the existing extent item. However, unlike the other inline refs, + * there is one one owner ref per extent rather than one per extent. + * + * Because of this, it goes at the front of the list of inline refs, and thus + * must have a lower type value than any other inline ref type (to satisfy the + * disk format rule that inline refs have non-decreasing type). + */ +#define BTRFS_EXTENT_OWNER_REF_KEY 172 + #define BTRFS_TREE_BLOCK_REF_KEY 176 #define BTRFS_EXTENT_DATA_REF_KEY 178 @@ -233,14 +249,6 @@ #define BTRFS_SHARED_DATA_REF_KEY 184 -/* - * Special inline ref key which stores the id of the subvolume which originally - * created the extent. This subvolume owns the extent permanently from the - * perspective of simple quotas. Needed to know which subvolume to free quota - * usage from when the extent is deleted. - */ -#define BTRFS_EXTENT_OWNER_REF_KEY 188 - /* * block groups give us hints into the extent allocation trees. Which * blocks are free etc etc -- cgit