gluster: add fallocate fop support

Implement support for the fallocate file operation. fallocate
allocates blocks for a particular inode such that future writes
to the associated region of the file are guaranteed not to fail
with ENOSPC.

This patch adds fallocate support to the following areas:

	- libglusterfs
	- mount/fuse
	- io-stats
	- performance/md-cache,open-behind
	- quota
	- cluster/afr,dht,stripe
	- rpc/xdr
	- protocol/client,server
	- io-threads
	- marker
	- storage/posix
	- libgfapi

BUG: 949242
Change-Id: Ice8e61351f9d6115c5df68768bc844abbf0ce8bd
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-on: http://review.gluster.org/4969
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

2 files changed, 73 insertions, 0 deletions

diff --git a/tests/bugs/bug-949242.t b/tests/bugs/bug-949242.t
new file mode 100644
index 00000000000..71708467350
--- /dev/null
+++ b/tests/bugs/bug-949242.t
@@ -0,0 +1,54 @@
+#!/bin/bash
+#
+# Bug 949242 - Test basic fallocate functionality.
+#
+# Run several commands to verify basic fallocate functionality. We verify that
+# fallocate creates and allocates blocks to a file. We also verify that the keep
+# size option does not modify the file size.
+###
+
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../fallocate.rc
+
+cleanup;
+
+TEST glusterd
+
+TEST $CLI volume create $V0 replica 2 $H0:$B0/${V0}{1,2,3,4}
+TEST $CLI volume start $V0
+
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 $M0 --attribute-timeout=0 --entry-timeout=0
+
+# check for fallocate support before continuing the test
+require_fallocate -l 1m -n $M0/file && rm -f $M0/file
+
+# fallocate a file and verify blocks are allocated
+TEST fallocate -l 1m $M0/file
+blksz=`stat --printf=%b $M0/file`
+nblks=`stat --printf=%B $M0/file`
+TEST [ $(($blksz * $nblks)) -eq 1048576 ]
+
+TEST unlink $M0/file
+
+# truncate a file to a fixed size, fallocate and verify that the size does not
+# change
+TEST truncate --size=1m $M0/file
+TEST fallocate -l 2m -n $M0/file
+blksz=`stat --printf=%b $M0/file`
+nblks=`stat --printf=%B $M0/file`
+sz=`stat --printf=%s $M0/file`
+TEST [ $sz -eq 1048576 ]
+# Note that gluster currently incorporates a hack to limit the number of blocks
+# reported as allocated to the file by the file size. We have allocated beyond the
+# file size here. Just check for non-zero allocation to avoid setting a land mine
+# for if/when that behavior might change.
+TEST [ ! $(($blksz * $nblks)) -eq 0 ]
+
+TEST unlink $M0/file
+
+TEST umount $M0
+
+TEST $CLI volume stop $V0
+TEST $CLI volume delete $V0
+
+cleanup;
diff --git a/tests/fallocate.rc b/tests/fallocate.rc
new file mode 100644
index 00000000000..3756bb949bd
--- /dev/null
+++ b/tests/fallocate.rc
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+# Helper to verify a given fallocate command is supported and skip a test
+# otherwise. Older versions of the fallocate utility might not support all modes
+# (i.e., discard) and older versions of fuse might not support the associated
+# fallocate requests.
+
+function require_fallocate()
+{
+	output=`fallocate $* 2>&1`
+	ret=$?
+	if [ ! $ret -eq 0 ] && ([[ $output == *unsupported* ]] ||
+				[[ $output == *invalid* ]] ||
+				[[ $output == *"not supported"* ]])
+	then
+		SKIP_TESTS
+		exit
+	fi
+}