[PATCH v3] btrfs-progs: add verbose option to btrfs device scan

[Anand Jain <anand.jain@oracle.com>]

To help debug device scan issues, add verbose option to btrfs device scan.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Tested-by: Graham Cobb <g.btrfs@cobb.uk.net>
---
v3: Add --verbose long option and update documentation. Thanks Graham.A
    Add Tested-by.
v2: Use bool instead of int as a btrfs_scan_device() argument.

 Documentation/btrfs-device.asciidoc | 2 ++
 cmds/device.c                       | 9 +++++++--
 cmds/filesystem.c                   | 2 +-
 common/device-scan.c                | 4 +++-
 common/device-scan.h                | 3 ++-
 common/utils.c                      | 2 +-
 disk-io.c                           | 2 +-
 7 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/Documentation/btrfs-device.asciidoc b/Documentation/btrfs-device.asciidoc
index 70ce6c5a97f8..a251be9e0fa2 100644
--- a/Documentation/btrfs-device.asciidoc
+++ b/Documentation/btrfs-device.asciidoc
@@ -120,6 +120,8 @@ available.
 -u|--forget::::
 Unregister a given device or all stale devices if no path is given, the device
 must be unmounted otherwise it's an error.
+-v|--verbose::::
+Be verbose and list the devices scanned.
 
 *stats* [options] <path>|<device>::
 Read and print the device IO error statistics for all devices of the given
diff --git a/cmds/device.c b/cmds/device.c
index 24158308a41b..655b97d83cb7 100644
--- a/cmds/device.c
+++ b/cmds/device.c
@@ -313,6 +313,7 @@ static int cmd_device_scan(const struct cmd_struct *cmd, int argc, char **argv)
 	int all = 0;
 	int ret = 0;
 	int forget = 0;
+	bool verbose = false;
 
 	optind = 0;
 	while (1) {
@@ -320,10 +321,11 @@ static int cmd_device_scan(const struct cmd_struct *cmd, int argc, char **argv)
 		static const struct option long_options[] = {
 			{ "all-devices", no_argument, NULL, 'd'},
 			{ "forget", no_argument, NULL, 'u'},
+			{ "verbose", no_argument, NULL, 'v'},
 			{ NULL, 0, NULL, 0}
 		};
 
-		c = getopt_long(argc, argv, "du", long_options, NULL);
+		c = getopt_long(argc, argv, "duv", long_options, NULL);
 		if (c < 0)
 			break;
 		switch (c) {
@@ -333,6 +335,9 @@ static int cmd_device_scan(const struct cmd_struct *cmd, int argc, char **argv)
 		case 'u':
 			forget = 1;
 			break;
+		case 'v':
+			verbose = true;
+			break;
 		default:
 			usage_unknown_option(cmd, argv);
 		}
@@ -354,7 +359,7 @@ static int cmd_device_scan(const struct cmd_struct *cmd, int argc, char **argv)
 			}
 		} else {
 			printf("Scanning for Btrfs filesystems\n");
-			ret = btrfs_scan_devices();
+			ret = btrfs_scan_devices(verbose);
 			error_on(ret, "error %d while scanning", ret);
 			ret = btrfs_register_all_devices();
 			error_on(ret,
diff --git a/cmds/filesystem.c b/cmds/filesystem.c
index 4f22089abeaa..02d47a43a792 100644
--- a/cmds/filesystem.c
+++ b/cmds/filesystem.c
@@ -746,7 +746,7 @@ devs_only:
 		else
 			ret = 1;
 	} else {
-		ret = btrfs_scan_devices();
+		ret = btrfs_scan_devices(false);
 	}
 
 	if (ret) {
diff --git a/common/device-scan.c b/common/device-scan.c
index 48dbd9e19715..a500edf0f7d7 100644
--- a/common/device-scan.c
+++ b/common/device-scan.c
@@ -360,7 +360,7 @@ void free_seen_fsid(struct seen_fsid *seen_fsid_hash[])
 	}
 }
 
-int btrfs_scan_devices(void)
+int btrfs_scan_devices(bool verbose)
 {
 	int fd = -1;
 	int ret;
@@ -389,6 +389,8 @@ int btrfs_scan_devices(void)
 			continue;
 		/* if we are here its definitely a btrfs disk*/
 		strncpy_null(path, blkid_dev_devname(dev));
+		if (verbose)
+			printf("blkid: btrfs device: %s\n", path);
 
 		fd = open(path, O_RDONLY);
 		if (fd < 0) {
diff --git a/common/device-scan.h b/common/device-scan.h
index eda2bae5c6c4..3e473c48d1af 100644
--- a/common/device-scan.h
+++ b/common/device-scan.h
@@ -1,6 +1,7 @@
 #ifndef __DEVICE_SCAN_H__
 #define __DEVICE_SCAN_H__
 
+#include <stdbool.h>
 #include "kerncompat.h"
 #include "ioctl.h"
 
@@ -29,7 +30,7 @@ struct seen_fsid {
 	int fd;
 };
 
-int btrfs_scan_devices(void);
+int btrfs_scan_devices(bool verbose);
 int btrfs_register_one_device(const char *fname);
 int btrfs_register_all_devices(void);
 int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
diff --git a/common/utils.c b/common/utils.c
index 6617b3ef38b1..9027de596f5d 100644
--- a/common/utils.c
+++ b/common/utils.c
@@ -277,7 +277,7 @@ int check_mounted_where(int fd, const char *file, char *where, int size,
 
 	/* scan other devices */
 	if (is_btrfs && total_devs > 1) {
-		ret = btrfs_scan_devices();
+		ret = btrfs_scan_devices(false);
 		if (ret)
 			return ret;
 	}
diff --git a/disk-io.c b/disk-io.c
index fa679133e171..58861ccfb4ec 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -1096,7 +1096,7 @@ int btrfs_scan_fs_devices(int fd, const char *path,
 	}
 
 	if (!skip_devices && total_devs != 1) {
-		ret = btrfs_scan_devices();
+		ret = btrfs_scan_devices(false);
 		if (ret)
 			return ret;
 	}
-- 
1.8.3.1