Merge tag 'kvm-x86-fixes-6.11-rcN' of https://github.com/kvm-x86/linux into kvm-master

KVM x86 fixes for 6.11

 - Fixup missed comments from the REMOVED_SPTE=>FROZEN_SPTE rename.

 - Ensure a root is successfully loaded when pre-faulting SPTEs.

 - Grab kvm->srcu when handling KVM_SET_VCPU_EVENTS to guard against accessing
   memslots if toggling SMM happens to force a VM-Exit.

 - Emulate MSR_{FS,GS}_BASE on SVM even though interception is always disabled,
   so that KVM does the right thing if KVM's emulator encounters {RD,WR}MSR.

 - Explicitly clear BUS_LOCK_DETECT from KVM's caps on AMD, as KVM doesn't yet
   virtualize BUS_LOCK_DETECT on AMD.

 - Cleanup the help message for CONFIG_KVM_AMD_SEV, and call out that KVM now
   supports SEV-SNP too.

1 files changed, 40 insertions, 14 deletions

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 4ca711a773ef..619fa0b8b3f6 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -347,7 +347,7 @@ struct name_cache_entry {
 	int ret;
 	int need_later_update;
 	int name_len;
-	char name[];
+	char name[] __counted_by(name_len);
 };
 
 /* See the comment at lru_cache.h about struct btrfs_lru_cache_entry. */
@@ -6157,25 +6157,51 @@ static int send_write_or_clone(struct send_ctx *sctx,
 	u64 offset = key->offset;
 	u64 end;
 	u64 bs = sctx->send_root->fs_info->sectorsize;
+	struct btrfs_file_extent_item *ei;
+	u64 disk_byte;
+	u64 data_offset;
+	u64 num_bytes;
+	struct btrfs_inode_info info = { 0 };
 
 	end = min_t(u64, btrfs_file_extent_end(path), sctx->cur_inode_size);
 	if (offset >= end)
 		return 0;
 
-	if (clone_root && IS_ALIGNED(end, bs)) {
-		struct btrfs_file_extent_item *ei;
-		u64 disk_byte;
-		u64 data_offset;
+	num_bytes = end - offset;
 
-		ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
-				    struct btrfs_file_extent_item);
-		disk_byte = btrfs_file_extent_disk_bytenr(path->nodes[0], ei);
-		data_offset = btrfs_file_extent_offset(path->nodes[0], ei);
-		ret = clone_range(sctx, path, clone_root, disk_byte,
-				  data_offset, offset, end - offset);
-	} else {
-		ret = send_extent_data(sctx, path, offset, end - offset);
-	}
+	if (!clone_root)
+		goto write_data;
+
+	if (IS_ALIGNED(end, bs))
+		goto clone_data;
+
+	/*
+	 * If the extent end is not aligned, we can clone if the extent ends at
+	 * the i_size of the inode and the clone range ends at the i_size of the
+	 * source inode, otherwise the clone operation fails with -EINVAL.
+	 */
+	if (end != sctx->cur_inode_size)
+		goto write_data;
+
+	ret = get_inode_info(clone_root->root, clone_root->ino, &info);
+	if (ret < 0)
+		return ret;
+
+	if (clone_root->offset + num_bytes == info.size)
+		goto clone_data;
+
+write_data:
+	ret = send_extent_data(sctx, path, offset, num_bytes);
+	sctx->cur_inode_next_write_offset = end;
+	return ret;
+
+clone_data:
+	ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
+			    struct btrfs_file_extent_item);
+	disk_byte = btrfs_file_extent_disk_bytenr(path->nodes[0], ei);
+	data_offset = btrfs_file_extent_offset(path->nodes[0], ei);
+	ret = clone_range(sctx, path, clone_root, disk_byte, data_offset, offset,
+			  num_bytes);
 	sctx->cur_inode_next_write_offset = end;
 	return ret;
 }