[PATCH 1/2] common/dmlogwrites: add _require_logwrites_size helper

Disha Goel
2026-04-14T10:21:10Z

Add a new helper function _require_logwrites_size() to check if the
LOGWRITES_DEV meets a minimum size requirement.

This is useful for tests that use dm-log-writes with additional space
requirements, such as creating LVM snapshots during log replay or tests
that generate large amounts of logged I/O operations.

The function takes a size parameter in KB and skips the test if
LOGWRITES_DEV is smaller than the required size.

Signed-off-by: Disha Goel <disgoel@linux.ibm.com>
---
common/dmlogwrites | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/common/dmlogwrites b/common/dmlogwrites
index a27e1966..1ce2b2fb 100644
--- a/common/dmlogwrites
+++ b/common/dmlogwrites
@@ -14,6 +14,15 @@ _require_log_writes()
_require_test_program "log-writes/replay-log"
}

+_require_logwrites_size()
+{
+ [ $# -eq 1 ] || _fail "_require_logwrites_size: expected size param"
+
+ local devsize=$(_get_device_size $LOGWRITES_DEV)
+ [ $devsize -lt $1 ] && \
+ _notrun "LOGWRITES_DEV too small, ${devsize}KB < $1KB"
+}
+
# Starting from v4.15-rc1, DAX support was added to dm-log-writes, but note
# that it doesn't track the data that we write via the mmap(), so we can't do
# any data integrity checking. We can only verify that the metadata writes for
--
2.45.1