copy_file_range: fix fallback when source create on same txg

In 019dea0 we removed the conversion from EAGAIN->EXDEV inside
zfs_clone_range(), but forgot to add a test for EAGAIN to the
copy_file_range() entry points to trigger fallback to a content copy.

This commit fixes that.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Kay Pedersen <mail@mkwg.de>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes #15170
Closes #15172

module/os/freebsd/zfs/zfs_vnops_os.c

@@ -6288,7 +6288,8 @@ zfs_freebsd_copy_file_range(struct vop_copy_file_range_args *ap)
 
 	error = zfs_clone_range(VTOZ(invp), ap->a_inoffp, VTOZ(outvp),
 	    ap->a_outoffp, &len, ap->a_outcred);
-	if (error == EXDEV || error == EINVAL || error == EOPNOTSUPP)
+	if (error == EXDEV || error == EAGAIN || error == EINVAL ||
+	    error == EOPNOTSUPP)
 		goto bad_locked_fallback;
 	*ap->a_lenp = (size_t)len;
 out_locked:

module/os/linux/zfs/zpl_file_range.c

@@ -103,15 +103,16 @@ zpl_copy_file_range(struct file *src_file, loff_t src_off,
 	 * Since Linux 5.3 the filesystem driver is responsible for executing
 	 * an appropriate fallback, and a generic fallback function is provided.
 	 */
-	if (ret == -EOPNOTSUPP || ret == -EINVAL || ret == -EXDEV)
+	if (ret == -EOPNOTSUPP || ret == -EINVAL || ret == -EXDEV ||
+	    ret == -EAGAIN)
 		ret = generic_copy_file_range(src_file, src_off, dst_file,
 		    dst_off, len, flags);
 #else
 	/*
 	 * Before Linux 5.3 the filesystem has to return -EOPNOTSUPP to signal
 	 * to the kernel that it should fallback to a content copy.
 	 */
-	if (ret == -EINVAL || ret == -EXDEV)
+	if (ret == -EINVAL || ret == -EXDEV || ret == -EAGAIN)
 		ret = -EOPNOTSUPP;
 #endif /* HAVE_VFS_GENERIC_COPY_FILE_RANGE */
 

module/zfs/zfs_vnops.c

@@ -1246,9 +1246,10 @@ zfs_clone_range(znode_t *inzp, uint64_t *inoffp, znode_t *outzp,
 		    &nbps);
 		if (error != 0) {
 			/*
-			 * If we are tyring to clone a block that was created
-			 * in the current transaction group. Return an error,
-			 * so the caller can fallback to just copying the data.
+			 * If we are trying to clone a block that was created
+			 * in the current transaction group, error will be
+			 * EAGAIN here, which we can just return to the caller
+			 * so it can fallback if it likes.
 			 */
 			break;
 		}

tests/runfiles/linux.run

@@ -41,7 +41,8 @@ tests = ['block_cloning_copyfilerange', 'block_cloning_copyfilerange_partial',
     'block_cloning_ficlonerange_partial',
     'block_cloning_disabled_copyfilerange', 'block_cloning_disabled_ficlone',
     'block_cloning_disabled_ficlonerange',
-    'block_cloning_copyfilerange_cross_dataset']
+    'block_cloning_copyfilerange_cross_dataset',
+    'block_cloning_copyfilerange_fallback_same_txg']
 tags = ['functional', 'block_cloning']
 
 [tests/functional/chattr:Linux]

tests/test-runner/bin/zts-report.py.in

@@ -304,6 +304,8 @@ elif sys.platform.startswith('linux'):
             ['SKIP', cfr_reason],
         'block_cloning/block_cloning_copyfilerange_cross_dataset':
             ['SKIP', cfr_cross_reason],
+        'block_cloning/block_cloning_copyfilerange_fallback_same_txg':
+            ['SKIP', cfr_cross_reason],
     })
 
 

tests/zfs-tests/tests/Makefile.am

@@ -441,9 +441,10 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/block_cloning/cleanup.ksh \
 	functional/block_cloning/setup.ksh \
 	functional/block_cloning/block_cloning_copyfilerange_cross_dataset.ksh \
+	functional/block_cloning/block_cloning_copyfilerange_fallback.ksh \
+	functional/block_cloning/block_cloning_copyfilerange_fallback_same_txg.ksh \
 	functional/block_cloning/block_cloning_copyfilerange.ksh \
 	functional/block_cloning/block_cloning_copyfilerange_partial.ksh \
-	functional/block_cloning/block_cloning_copyfilerange_fallback.ksh \
 	functional/block_cloning/block_cloning_disabled_copyfilerange.ksh \
 	functional/block_cloning/block_cloning_disabled_ficlone.ksh \
 	functional/block_cloning/block_cloning_disabled_ficlonerange.ksh \

tests/zfs-tests/tests/functional/block_cloning/block_cloning_copyfilerange_fallback_same_txg.ksh

@@ -0,0 +1,66 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or https://opensource.org/licenses/CDDL-1.0.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2023, Klara Inc.
+# Copyright (c) 2023, Rob Norris <robn@despairlabs.com>
+#
+
+. $STF_SUITE/include/libtest.shlib
+. $STF_SUITE/tests/functional/block_cloning/block_cloning.kshlib
+
+verify_runnable "global"
+
+if [[ $(linux_version) -lt $(linux_version "4.5") ]]; then
+  log_unsupported "copy_file_range not available before Linux 4.5"
+fi
+
+claim="copy_file_range will fall back to copy when cloning on same txg"
+
+log_assert $claim
+
+typeset timeout=$(get_tunable TXG_TIMEOUT)
+
+function cleanup
+{
+	datasetexists $TESTPOOL && destroy_pool $TESTPOOL
+	set_tunable64 TXG_TIMEOUT $timeout
+}
+
+log_onexit cleanup
+
+log_must zpool create -o feature@block_cloning=enabled $TESTPOOL $DISKS
+
+log_must set_tunable64 TXG_TIMEOUT 5000
+
+log_must dd if=/dev/urandom of=/$TESTPOOL/file bs=128K count=4
+log_must clonefile -f /$TESTPOOL/file /$TESTPOOL/clone 0 0 524288
+
+log_must sync_pool $TESTPOOL
+
+log_must have_same_content /$TESTPOOL/file /$TESTPOOL/clone
+
+typeset blocks=$(unique_blocks $TESTPOOL file $TESTPOOL clone)
+log_must [ "$blocks" = "" ]
+
+log_pass $claim
+