[PATCH v2] ext4: the _require checks for bigalloc need a larger fs size

[PATCH v2] ext4: the _require checks for bigalloc need a larger fs size

[Vishal Verma]

_require_ext4_bigalloc and _require_ext4_mkfs_bigalloc create a
200k fs. DAX (as XIP before it) relies on a fs block size ==
system page size; ie 4k for us.  With a 200k fs size limit,
mkfs refuses to create a filesystem with a 4k block size, so
the check fails, but for a bogus reason.
Increasing the fs size to 512m allows mkfs to create a filesystem
with 4k block size, so the test passes.

Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---

v1->v2 Update commit log with feedback from Matthew.

 common/rc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/common/rc b/common/rc
index d5e3aff..615a446 100644
--- a/common/rc
+++ b/common/rc
@@ -1314,7 +1314,7 @@ _require_xfs_crc()
 #
 _require_ext4_mkfs_bigalloc()
 {
-	$MKFS_EXT4_PROG -F -O bigalloc -n $SCRATCH_DEV 200k >/dev/null 2>&1 \
+	$MKFS_EXT4_PROG -F -O bigalloc -n $SCRATCH_DEV 512m >/dev/null 2>&1 \
 	   || _notrun "mkfs.ext4 doesn't have bigalloc feature"
 }
 
@@ -1322,7 +1322,7 @@ _require_ext4_mkfs_bigalloc()
 #
 _require_ext4_bigalloc()
 {
-	$MKFS_EXT4_PROG -F -O bigalloc $SCRATCH_DEV 200k >/dev/null 2>&1
+	$MKFS_EXT4_PROG -F -O bigalloc $SCRATCH_DEV 512m >/dev/null 2>&1
 	_scratch_mount >/dev/null 2>&1 \
 	   || _notrun "Ext4 kernel doesn't support bigalloc feature"
 	umount $SCRATCH_MNT
-- 
2.1.0

Re: [PATCH v2] ext4: the _require checks for bigalloc need a larger fs size

[Theodore Ts'o]

On Thu, Dec 11, 2014 at 03:11:20PM -0700, Vishal Verma wrote:
> _require_ext4_bigalloc and _require_ext4_mkfs_bigalloc create a
> 200k fs. DAX (as XIP before it) relies on a fs block size ==
> system page size; ie 4k for us.  With a 200k fs size limit,
> mkfs refuses to create a filesystem with a 4k block size, so
> the check fails, but for a bogus reason.
> Increasing the fs size to 512m allows mkfs to create a filesystem
> with 4k block size, so the test passes.
> 
> Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com>
> Signed-off-by: Matthew Wilcox <willy@linux.intel.com>

LGTM

Reviewed-by: Theodore Ts'o <tytso@mit.edu>

						- Ted