[v2] utils/mount/nfs.man: add noalignwrite

Commit Message

Dan Aloni March 10, 2025, 12:52 p.m. UTC

Signed-off-by: Dan Aloni <[e-mail]>
---
 utils/mount/nfs.man | 11 +++++++++++
 1 file changed, 11 insertions(+)

Patch

diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man
index eab4692a87de..b5c5913bf315 100644
--- a/utils/mount/nfs.man
+++ b/utils/mount/nfs.man
@@ -618,6 +618,17 @@  option is not specified,
 the default behavior depends on the kernel version,
 but is usually equivalent to
 .BR "xprtsec=none" .
+.TP 1.5i
+.BI noalignwrite
+This option disables the default behavior of extending buffered write operations
+to full page boundaries.
+.IP
+Normally, the NFS client rounds non-aligned buffered writes up to the system
+page size, which can lead to "lost writes" when multiple clients write
+concurrently to distinct non-overlapping regions. Use this option when your
+applications perform non-aligned buffered writes and you can guarantee that file
+regions do not overlap, thus avoiding the need for file locking.
+.IP
 .SS "Options for NFS versions 2 and 3 only"
 Use these options, along with the options in the above subsection,
 for NFS versions 2 and 3 only.