Add nocow info in 'qemu-img info' output to show whether the file
currently has NOCOW flag set or not.
Signed-off-by: Chunyan Liu <cy...@suse.com>
---
Changes:
- add documentation of "nocow" in qapi/block-core.json.
block/qapi.c | 25 +++++++++++++++++++++++++
qapi/block-core.json | 5 ++++-
2 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/block/qapi.c b/block/qapi.c
index f44f6b4..16ccf2f 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -28,6 +28,13 @@
#include "qapi-visit.h"
#include "qapi/qmp-output-visitor.h"
#include "qapi/qmp/types.h"
+#ifdef __linux__
+#include <linux/fs.h>
+#include <sys/ioctl.h>
+#ifndef FS_NOCOW_FL
+#define FS_NOCOW_FL 0x00800000 /* Do not cow file */
+#endif
+#endif
BlockDeviceInfo *bdrv_block_device_info(BlockDriverState *bs)
{
@@ -173,6 +180,20 @@ void bdrv_query_image_info(BlockDriverState *bs,
Error *err = NULL;
ImageInfo *info = g_new0(ImageInfo, 1);
+#ifdef __linux__
+ int fd, attr;
+
+ /* get NOCOW info */
+ fd = qemu_open(bs->filename, O_RDONLY | O_NONBLOCK);
+ if (fd >= 0) {
+ if (ioctl(fd, FS_IOC_GETFLAGS, &attr) == 0 && (attr & FS_NOCOW_FL)) {
+ info->has_nocow = true;
+ info->nocow = true;
+ }
+ qemu_close(fd);
+ }
+#endif
+
bdrv_get_geometry(bs, &total_sectors);
info->filename = g_strdup(bs->filename);
@@ -625,4 +646,8 @@ void bdrv_image_info_dump(fprintf_function func_fprintf,
void *f,
func_fprintf(f, "Format specific information:\n");
bdrv_image_info_specific_dump(func_fprintf, f, info->format_specific);
}
+
+ if (info->has_nocow && info->nocow) {
+ func_fprintf(f, "Set NOCOW flag: yes\n");
+ }
}
diff --git a/qapi/block-core.json b/qapi/block-core.json
index e378653..deb785b 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -115,6 +115,8 @@
# @format-specific: #optional structure supplying additional format-specific
# information (since 1.7)
#
+# @nocow: #optional info of whether NOCOW flag is set or not. (since 2.1)
+#
# Since: 1.3
#
##
@@ -126,7 +128,8 @@
'*backing-filename': 'str', '*full-backing-filename': 'str',
'*backing-filename-format': 'str', '*snapshots': ['SnapshotInfo'],
'*backing-image': 'ImageInfo',
- '*format-specific': 'ImageInfoSpecific' } }
+ '*format-specific': 'ImageInfoSpecific',
+ '*nocow': 'bool' } }
##
# @ImageCheck:
--
1.8.4.5
