KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/fs/autofs/Kconfig b/fs/autofs/Kconfig
new file mode 100644
index 000000000..54c12d948
--- /dev/null
+++ b/fs/autofs/Kconfig
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config AUTOFS_FS
+	tristate "Kernel automounter support (supports v3, v4 and v5)"
+	help
+	   The automounter is a tool to automatically mount remote file systems
+	   on demand. This implementation is partially kernel-based to reduce
+	   overhead in the already-mounted case; this is unlike the BSD
+	   automounter (amd), which is a pure user space daemon.
+
+	   To use the automounter you need the user-space tools from
+	   <https://www.kernel.org/pub/linux/daemons/autofs/>; you also want
+	   to answer Y to "NFS file system support", below.
+
+	   To compile this support as a module, choose M here: the module will be
+	   called autofs.
+
+	   If you are not a part of a fairly large, distributed network or
+	   don't have a laptop which needs to dynamically reconfigure to the
+	   local network, you probably do not need an automounter, and can say
+	   N here.