diff --git a/0014-tests-Add-more-generic-tests-of-file-cache-none.patch b/0014-tests-Add-more-generic-tests-of-file-cache-none.patch
new file mode 100644
index 0000000..0f2038e
--- /dev/null
+++ b/0014-tests-Add-more-generic-tests-of-file-cache-none.patch
@@ -0,0 +1,238 @@
+From bdab63138758e287b292140e17f2d0e3b4c40bbe Mon Sep 17 00:00:00 2001
+From: "Richard W.M. Jones" <rjones@redhat.com>
+Date: Tue, 1 Apr 2025 12:45:43 +0100
+Subject: [PATCH] tests: Add more generic tests of file cache=none
+
+The tests added in commit 6017ba21ae require cachestats which means
+they are almost always skipped in reality.  Also we're interested in
+whether the windowed eviction could ever corrupt data.  Write a
+simpler pair of tests for data integrity.
+
+Updates: commit 6017ba21aeeb3d7ad85925e78dba85a005194dee
+(cherry picked from commit 7b45f73c0668e56a9188249eeefc2f67aeb50af3)
+---
+ tests/Makefile.am                             | 12 +++--
+ tests/test-file-cache-none-read-consistent.sh | 53 ++++++++++++++++++
+ ...=> test-file-cache-none-read-effective.sh} |  9 ++--
+ .../test-file-cache-none-write-consistent.sh  | 54 +++++++++++++++++++
+ ...> test-file-cache-none-write-effective.sh} | 11 ++--
+ 5 files changed, 126 insertions(+), 13 deletions(-)
+ create mode 100755 tests/test-file-cache-none-read-consistent.sh
+ rename tests/{test-file-cache-none-read.sh => test-file-cache-none-read-effective.sh} (93%)
+ create mode 100755 tests/test-file-cache-none-write-consistent.sh
+ rename tests/{test-file-cache-none-write.sh => test-file-cache-none-write-effective.sh} (92%)
+
+diff --git a/tests/Makefile.am b/tests/Makefile.am
+index 4340cc38..eed96d28 100644
+--- a/tests/Makefile.am
++++ b/tests/Makefile.am
+@@ -846,8 +846,10 @@ TESTS += \
+ 	test-file-extents.sh \
+ 	test-file-dir.sh \
+ 	test-file-dirfd.sh \
+-	test-file-cache-none-read.sh \
+-	test-file-cache-none-write.sh \
++	test-file-cache-none-read-consistent.sh \
++	test-file-cache-none-read-effective.sh \
++	test-file-cache-none-write-consistent.sh \
++	test-file-cache-none-write-effective.sh \
+ 	$(NULL)
+ EXTRA_DIST += \
+ 	test-file.sh \
+@@ -857,8 +859,10 @@ EXTRA_DIST += \
+ 	test-file-extents.sh \
+ 	test-file-dir.sh \
+ 	test-file-dirfd.sh \
+-	test-file-cache-none-read.sh \
+-	test-file-cache-none-write.sh \
++	test-file-cache-none-read-consistent.sh \
++	test-file-cache-none-read-effective.sh \
++	test-file-cache-none-write-consistent.sh \
++	test-file-cache-none-write-effective.sh \
+ 	$(NULL)
+ LIBGUESTFS_TESTS += test-file-block
+ 
+diff --git a/tests/test-file-cache-none-read-consistent.sh b/tests/test-file-cache-none-read-consistent.sh
+new file mode 100755
+index 00000000..5f5794ee
+--- /dev/null
++++ b/tests/test-file-cache-none-read-consistent.sh
+@@ -0,0 +1,53 @@
++#!/usr/bin/env bash
++# nbdkit
++# Copyright Red Hat
++#
++# Redistribution and use in source and binary forms, with or without
++# modification, are permitted provided that the following conditions are
++# met:
++#
++# * Redistributions of source code must retain the above copyright
++# notice, this list of conditions and the following disclaimer.
++#
++# * Redistributions in binary form must reproduce the above copyright
++# notice, this list of conditions and the following disclaimer in the
++# documentation and/or other materials provided with the distribution.
++#
++# * Neither the name of Red Hat nor the names of its contributors may be
++# used to endorse or promote products derived from this software without
++# specific prior written permission.
++#
++# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
++# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
++# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
++# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
++# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
++# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
++# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
++# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
++# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
++# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
++# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
++# SUCH DAMAGE.
++
++# Test the file plugin, reading with cache=none.
++#
++# Unlike test-file-cache-none-read-effective.sh, this test doesn't
++# require cachestats.  It's more about testing integrity of reading.
++
++source ./functions.sh
++set -e
++set -x
++
++requires_plugin file
++requires_run
++requires_nbdcopy
++requires test -f disk
++requires md5sum --version
++
++out=file-cache-none-read-consistent.out
++cleanup_fn rm -f $out
++
++export out
++nbdkit file disk cache=none --run 'nbdcopy "$uri" "$out"'
++test "$(md5sum < disk)" = "$(md5sum < $out)"
+diff --git a/tests/test-file-cache-none-read.sh b/tests/test-file-cache-none-read-effective.sh
+similarity index 93%
+rename from tests/test-file-cache-none-read.sh
+rename to tests/test-file-cache-none-read-effective.sh
+index c9831b43..efead224 100755
+--- a/tests/test-file-cache-none-read.sh
++++ b/tests/test-file-cache-none-read-effective.sh
+@@ -30,7 +30,8 @@
+ # OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ # SUCH DAMAGE.
+ 
+-# Test the file plugin, reading with cache=none.
++# Test the file plugin, reading with cache=none, is effective at
++# reducing page cache usage.
+ 
+ source ./functions.sh
+ set -e
+@@ -52,9 +53,9 @@ requires $SED --version
+ requires type cachestats
+ requires type cachedel
+ 
+-inp=file-cache-none-read.in
+-stats1=file-cache-none-read.s1
+-stats2=file-cache-none-read.s2
++inp=file-cache-none-read-effective.in
++stats1=file-cache-none-read-effective.s1
++stats2=file-cache-none-read-effective.s2
+ rm -f $inp $stats1 $stats2
+ cleanup_fn rm -f $inp $stats1 $stats2
+ 
+diff --git a/tests/test-file-cache-none-write-consistent.sh b/tests/test-file-cache-none-write-consistent.sh
+new file mode 100755
+index 00000000..749805f1
+--- /dev/null
++++ b/tests/test-file-cache-none-write-consistent.sh
+@@ -0,0 +1,54 @@
++#!/usr/bin/env bash
++# nbdkit
++# Copyright Red Hat
++#
++# Redistribution and use in source and binary forms, with or without
++# modification, are permitted provided that the following conditions are
++# met:
++#
++# * Redistributions of source code must retain the above copyright
++# notice, this list of conditions and the following disclaimer.
++#
++# * Redistributions in binary form must reproduce the above copyright
++# notice, this list of conditions and the following disclaimer in the
++# documentation and/or other materials provided with the distribution.
++#
++# * Neither the name of Red Hat nor the names of its contributors may be
++# used to endorse or promote products derived from this software without
++# specific prior written permission.
++#
++# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
++# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
++# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
++# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
++# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
++# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
++# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
++# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
++# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
++# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
++# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
++# SUCH DAMAGE.
++
++# Test the file plugin, writing with cache=none.
++#
++# Unlike test-file-cache-none-write-effective.sh, this test doesn't
++# require cachestats.  It's more about testing integrity of writing.
++
++source ./functions.sh
++set -e
++set -x
++
++requires_plugin file
++requires_run
++requires_nbdcopy
++requires test -f disk
++requires md5sum --version
++requires $TRUNCATE --version
++
++out=file-cache-none-write-consistent.out
++cleanup_fn rm -f $out
++
++rm -f $out; $TRUNCATE -r disk $out
++nbdkit file $out cache=none --run 'nbdcopy disk "$uri"'
++test "$(md5sum < disk)" = "$(md5sum < $out)"
+diff --git a/tests/test-file-cache-none-write.sh b/tests/test-file-cache-none-write-effective.sh
+similarity index 92%
+rename from tests/test-file-cache-none-write.sh
+rename to tests/test-file-cache-none-write-effective.sh
+index 2041a5cd..e0159242 100755
+--- a/tests/test-file-cache-none-write.sh
++++ b/tests/test-file-cache-none-write-effective.sh
+@@ -30,7 +30,8 @@
+ # OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ # SUCH DAMAGE.
+ 
+-# Test the file plugin, writing with cache=none.
++# Test the file plugin, writing with cache=none, is effective at
++# reducing page cache usage.
+ 
+ source ./functions.sh
+ set -e
+@@ -51,10 +52,10 @@ requires $SED --version
+ # It doesn't support --version or --help, so use 'type' instead.
+ requires type cachestats
+ 
+-inp=file-cache-none-write.in
+-out=file-cache-none-write.out
+-stats1=file-cache-none-write.s1
+-stats2=file-cache-none-write.s2
++inp=file-cache-none-write-effective.in
++out=file-cache-none-write-effective.out
++stats1=file-cache-none-write-effective.s1
++stats2=file-cache-none-write-effective.s2
+ rm -f $inp $out $stats1 $stats2
+ cleanup_fn rm -f $inp $out $stats1 $stats2
+ 
+-- 
+2.47.1
+
diff --git a/0015-file-Hard-error-if-sync_file_range-fails.patch b/0015-file-Hard-error-if-sync_file_range-fails.patch
new file mode 100644
index 0000000..7b993a5
--- /dev/null
+++ b/0015-file-Hard-error-if-sync_file_range-fails.patch
@@ -0,0 +1,101 @@
+From 2772bc3e81cb0c396bde186a2581d010b8d19e5d Mon Sep 17 00:00:00 2001
+From: "Richard W.M. Jones" <rjones@redhat.com>
+Date: Tue, 1 Apr 2025 11:07:51 +0100
+Subject: [PATCH] file: Hard error if sync_file_range fails
+
+After discussion with Dave Chinner, it appears that I/O errors can be
+returned by sync_file_range, ie. it is not merely a hint to start the
+eviction.  Therefore return a hard error if any of the sync_file_range
+calls fails.
+
+Thanks: Dave Chinner
+Updates: commit d35f0636373e6a58c8f3fcfcf505af248e27c574
+(cherry picked from commit d2ed6a839c3ed50b417f45dc13e5b811ecdc4e74)
+---
+ plugins/file/file.c | 53 ++++++++++++++++++++++++---------------------
+ 1 file changed, 28 insertions(+), 25 deletions(-)
+
+diff --git a/plugins/file/file.c b/plugins/file/file.c
+index 638c960d..f195bcf3 100644
+--- a/plugins/file/file.c
++++ b/plugins/file/file.c
+@@ -116,7 +116,7 @@ struct write_window {
+ static pthread_mutex_t window_lock = PTHREAD_MUTEX_INITIALIZER;
+ static struct write_window window[NR_WINDOWS];
+ 
+-static void
++static int
+ evict_writes (int fd, uint64_t offset, size_t len)
+ {
+   ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&window_lock);
+@@ -125,31 +125,32 @@ evict_writes (int fd, uint64_t offset, size_t len)
+    * (asynchronously).
+    */
+   if (sync_file_range (fd, offset, len, SYNC_FILE_RANGE_WRITE) == -1) {
+-    /* sync_file_range to start the write failed */
+-    nbdkit_debug ("sync_file_range: write: (ignored): %m");
++    nbdkit_error ("sync_file_range: cache=none: starting eviction: %m");
++    return -1;
+   }
+-  else {
+-    /* sync_file_range to start the write succeeded, so
+-     * evict the oldest window from the page cache.
+-     */
+-    if (window[0].len > 0) {
+-      if (sync_file_range (window[0].fd, window[0].offset, window[0].len,
+-                           SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|
+-                           SYNC_FILE_RANGE_WAIT_AFTER) == -1)
+-        nbdkit_debug ("sync_file_range: wait: (ignored): %m");
+-      if (posix_fadvise (window[0].fd, window[0].offset, window[0].len,
+-                         POSIX_FADV_DONTNEED) == -1)
+-        nbdkit_debug ("posix_fadvise: POSIX_FADV_DONTNEED: (ignored): %m");
++
++  /* Evict the oldest window from the page cache. */
++  if (window[0].len > 0) {
++    if (sync_file_range (window[0].fd, window[0].offset, window[0].len,
++                         SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|
++                         SYNC_FILE_RANGE_WAIT_AFTER) == -1) {
++      nbdkit_error ("sync_file_range: cache=none: evicting oldest window: %m");
++      return -1;
+     }
+-
+-    /* Move the Nth window to N-1. */
+-    memmove (&window[0], &window[1], sizeof window[0] * (NR_WINDOWS-1));
+-
+-    /* Add the range to the newest end of the list of windows. */
+-    window[NR_WINDOWS-1].fd = fd;
+-    window[NR_WINDOWS-1].offset = offset;
+-    window[NR_WINDOWS-1].len = len;
++    if (posix_fadvise (window[0].fd, window[0].offset, window[0].len,
++                       POSIX_FADV_DONTNEED) == -1)
++      nbdkit_debug ("posix_fadvise: POSIX_FADV_DONTNEED: (ignored): %m");
+   }
++
++  /* Move the Nth window to N-1. */
++  memmove (&window[0], &window[1], sizeof window[0] * (NR_WINDOWS-1));
++
++  /* Add the range to the newest end of the list of windows. */
++  window[NR_WINDOWS-1].fd = fd;
++  window[NR_WINDOWS-1].offset = offset;
++  window[NR_WINDOWS-1].len = len;
++
++  return 0;
+ }
+ 
+ /* When we close the handle we must remove any windows which are still
+@@ -855,8 +856,10 @@ file_pwrite (void *handle, const void *buf, uint32_t count, uint64_t offset,
+     return -1;
+ 
+ #if EVICT_WRITES
+-  if (cache_mode == cache_none)
+-    evict_writes (h->fd, orig_offset, orig_count);
++  if (cache_mode == cache_none) {
++    if (evict_writes (h->fd, orig_offset, orig_count) == -1)
++      return -1;
++  }
+ #endif
+ 
+   return 0;
+-- 
+2.47.1
+
diff --git a/0016-file-Reduce-the-size-of-the-lock-around-write-evicti.patch b/0016-file-Reduce-the-size-of-the-lock-around-write-evicti.patch
new file mode 100644
index 0000000..09abced
--- /dev/null
+++ b/0016-file-Reduce-the-size-of-the-lock-around-write-evicti.patch
@@ -0,0 +1,90 @@
+From 056a975578b42e8cbfd783b8b919c4ef02e40019 Mon Sep 17 00:00:00 2001
+From: "Richard W.M. Jones" <rjones@redhat.com>
+Date: Tue, 1 Apr 2025 11:56:22 +0100
+Subject: [PATCH] file: Reduce the size of the lock around write eviction
+
+Previously we held window_lock during the synchronous eviction of the
+oldest window.  This potentially serializes all writes in the slow
+write case.  We don't need to hold the lock here.
+
+(cherry picked from commit d3d2bc45bb59a30669a3d926435cf57e99feb3a2)
+---
+ plugins/file/file.c | 52 +++++++++++++++++++++++++++------------------
+ 1 file changed, 31 insertions(+), 21 deletions(-)
+
+diff --git a/plugins/file/file.c b/plugins/file/file.c
+index f195bcf3..e68c24ee 100644
+--- a/plugins/file/file.c
++++ b/plugins/file/file.c
+@@ -119,37 +119,47 @@ static struct write_window window[NR_WINDOWS];
+ static int
+ evict_writes (int fd, uint64_t offset, size_t len)
+ {
+-  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&window_lock);
+-
+-  /* Tell Linux to start writing the current range out to disk
+-   * (asynchronously).
+-   */
+-  if (sync_file_range (fd, offset, len, SYNC_FILE_RANGE_WRITE) == -1) {
+-    nbdkit_error ("sync_file_range: cache=none: starting eviction: %m");
+-    return -1;
++  struct write_window oldest = { 0 };
++
++  {
++    ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&window_lock);
++
++    /* Save oldest window[0] for eviction below, and move all windows
++     * down one.  Set the newest slot to empty.
++     */
++    oldest = window[0];
++    memmove (&window[0], &window[1], sizeof window[0] * (NR_WINDOWS-1));
++    window[NR_WINDOWS-1].len = 0;
++
++    /* Tell Linux to start writing the current range out to disk
++     * (asynchronously).
++     */
++    if (sync_file_range (fd, offset, len, SYNC_FILE_RANGE_WRITE) == -1) {
++      nbdkit_error ("sync_file_range: cache=none: starting eviction: %m");
++      return -1;
++    }
++
++    /* Add the range to the newest end of the list of windows. */
++    window[NR_WINDOWS-1].fd = fd;
++    window[NR_WINDOWS-1].offset = offset;
++    window[NR_WINDOWS-1].len = len;
+   }
++  /* Release lock here. */
+ 
+-  /* Evict the oldest window from the page cache. */
+-  if (window[0].len > 0) {
+-    if (sync_file_range (window[0].fd, window[0].offset, window[0].len,
+-                         SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|
++  /* Evict the oldest window from the page cache (synchronously). */
++  if (oldest.len > 0) {
++    if (sync_file_range (oldest.fd, oldest.offset, oldest.len,
++                         SYNC_FILE_RANGE_WAIT_BEFORE |
++                         SYNC_FILE_RANGE_WRITE |
+                          SYNC_FILE_RANGE_WAIT_AFTER) == -1) {
+       nbdkit_error ("sync_file_range: cache=none: evicting oldest window: %m");
+       return -1;
+     }
+-    if (posix_fadvise (window[0].fd, window[0].offset, window[0].len,
++    if (posix_fadvise (oldest.fd, oldest.offset, oldest.len,
+                        POSIX_FADV_DONTNEED) == -1)
+       nbdkit_debug ("posix_fadvise: POSIX_FADV_DONTNEED: (ignored): %m");
+   }
+ 
+-  /* Move the Nth window to N-1. */
+-  memmove (&window[0], &window[1], sizeof window[0] * (NR_WINDOWS-1));
+-
+-  /* Add the range to the newest end of the list of windows. */
+-  window[NR_WINDOWS-1].fd = fd;
+-  window[NR_WINDOWS-1].offset = offset;
+-  window[NR_WINDOWS-1].len = len;
+-
+   return 0;
+ }
+ 
+-- 
+2.47.1
+
diff --git a/0017-file-Document-implicit-assumption-about-eviction-win.patch b/0017-file-Document-implicit-assumption-about-eviction-win.patch
new file mode 100644
index 0000000..fcb1bff
--- /dev/null
+++ b/0017-file-Document-implicit-assumption-about-eviction-win.patch
@@ -0,0 +1,29 @@
+From 5f5f74fa0afae78365eb431a589a6fa4938b9287 Mon Sep 17 00:00:00 2001
+From: "Richard W.M. Jones" <rjones@redhat.com>
+Date: Tue, 1 Apr 2025 16:51:24 +0100
+Subject: [PATCH] file: Document implicit assumption about eviction windows
+
+Add a comment that slots in the window list are only valid when len > 0.
+This was true before but only implicit.
+
+(cherry picked from commit 2022ac667f3c1de81b692f0128dd83a7c4999e38)
+---
+ plugins/file/file.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/plugins/file/file.c b/plugins/file/file.c
+index e68c24ee..6bcc5537 100644
+--- a/plugins/file/file.c
++++ b/plugins/file/file.c
+@@ -110,7 +110,7 @@ static enum { cache_default, cache_none } cache_mode = cache_default;
+ struct write_window {
+   int fd;
+   uint64_t offset;
+-  size_t len;
++  size_t len;           /* window slot only valid if len > 0 */
+ };
+ 
+ static pthread_mutex_t window_lock = PTHREAD_MUTEX_INITIALIZER;
+-- 
+2.47.1
+
diff --git a/nbdkit.spec b/nbdkit.spec
index e28b86f..f040b28 100644
--- a/nbdkit.spec
+++ b/nbdkit.spec
@@ -56,7 +56,7 @@
 
 Name:           nbdkit
 Version:        1.38.5
-Release:        3%{?dist}
+Release:        4%{?dist}
 Summary:        NBD server
 
 License:        BSD-3-Clause
@@ -94,6 +94,10 @@ Patch0010:     0010-vddk-do_extents-Avoid-reading-partial-chunk-beyond-t.patch
 Patch0011:     0011-file-Add-debugging-if-sync_file_range-posix_fadvise-.patch
 Patch0012:     0012-file-If-sync_file_range-fails-to-start-don-t-add-win.patch
 Patch0013:     0013-tests-Add-tests-of-file-plugin-cache-none.patch
+Patch0014:     0014-tests-Add-more-generic-tests-of-file-cache-none.patch
+Patch0015:     0015-file-Hard-error-if-sync_file_range-fails.patch
+Patch0016:     0016-file-Reduce-the-size-of-the-lock-around-write-evicti.patch
+Patch0017:     0017-file-Document-implicit-assumption-about-eviction-win.patch
 
 # For automatic RPM Provides generation.
 # See: https://rpm-software-management.github.io/rpm/manual/dependency_generators.html
@@ -1512,7 +1516,7 @@ fi
 
 
 %changelog
-* Mon Mar 31 2025 Richard W.M. Jones <rjones@redhat.com> - 1.38.5-3
+* Tue Apr 01 2025 Richard W.M. Jones <rjones@redhat.com> - 1.38.5-4
 - Add extra system call checking and debugging to nbdkit-file-plugin
   resolves: RHEL-85510