[PATCH 10/10] Btrfs-progs: add show subcommand to subvol cli

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

This adds show sub-command to the btrfs subvol cli
to display detailed inforamtion of the given subvol
or snapshot.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 btrfs-list.c     |  25 +++++++--
 btrfs-list.h     |   3 +-
 cmds-subvolume.c | 155 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
 man/btrfs.8.in   |   6 +++
 4 files changed, 182 insertions(+), 7 deletions(-)

diff --git a/btrfs-list.c b/btrfs-list.c
index 656de10..1915ece 100644
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -1335,6 +1335,22 @@ static void print_subvolume_column(struct root_info *subv,
 	}
 }
 
+static void print_single_volume_info_raw(struct root_info *subv, char *raw_prefix)
+{
+	int i;
+
+	for (i = 0; i < BTRFS_LIST_ALL; i++) {
+		if (!btrfs_list_columns[i].need_print)
+			continue;
+
+		if (raw_prefix)
+			printf("%s",raw_prefix);
+
+		print_subvolume_column(subv, i);
+	}
+	printf("\n");
+}
+
 static void print_single_volume_info_table(struct root_info *subv)
 {
 	int i;
@@ -1401,7 +1417,7 @@ static void print_all_volume_info_tab_head()
 }
 
 static void print_all_volume_info(struct root_lookup *sorted_tree,
-				  int layout)
+				  int layout, char *raw_prefix)
 {
 	struct rb_node *n;
 	struct root_info *entry;
@@ -1419,6 +1435,9 @@ static void print_all_volume_info(struct root_lookup *sorted_tree,
 		case BTRFS_LIST_LAYOUT_TABLE:
 			print_single_volume_info_table(entry);
 			break;
+		case BTRFS_LIST_LAYOUT_RAW:
+			print_single_volume_info_raw(entry, raw_prefix);
+			break;
 		}
 		n = rb_next(n);
 	}
@@ -1445,7 +1464,7 @@ int btrfs_list_subvols(int fd, struct root_lookup *root_lookup)
 
 int btrfs_list_subvols_print(int fd, struct btrfs_list_filter_set *filter_set,
 		       struct btrfs_list_comparer_set *comp_set,
-		       int layout)
+		       int layout, char *raw_prefix)
 {
 	struct root_lookup root_lookup;
 	struct root_lookup root_sort;
@@ -1457,7 +1476,7 @@ int btrfs_list_subvols_print(int fd, struct btrfs_list_filter_set *filter_set,
 	__filter_and_sort_subvol(&root_lookup, &root_sort, filter_set,
 				 comp_set, fd);
 
-	print_all_volume_info(&root_sort, layout);
+	print_all_volume_info(&root_sort, layout, raw_prefix);
 	__free_all_subvolumn(&root_lookup);
 
 	return 0;
diff --git a/btrfs-list.h b/btrfs-list.h
index 5b60068..09d35f7 100644
--- a/btrfs-list.h
+++ b/btrfs-list.h
@@ -20,6 +20,7 @@
 
 #define BTRFS_LIST_LAYOUT_DEFAULT	0
 #define BTRFS_LIST_LAYOUT_TABLE	1
+#define BTRFS_LIST_LAYOUT_RAW		2
 
 /*
  * one of these for each root we find.
@@ -150,7 +151,7 @@ int btrfs_list_setup_comparer(struct btrfs_list_comparer_set **comp_set,
 
 int btrfs_list_subvols_print(int fd, struct btrfs_list_filter_set *filter_set,
 		       struct btrfs_list_comparer_set *comp_set,
-			int is_tab_result);
+			int layout, char *raw_prefix);
 int btrfs_list_find_updated_files(int fd, u64 root_id, u64 oldest_gen);
 int btrfs_list_get_default_subvolume(int fd, u64 *default_id);
 char *btrfs_list_path_for_root(int fd, u64 root);
diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index bb9629f..6a14c4c 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -24,6 +24,7 @@
 #include <libgen.h>
 #include <limits.h>
 #include <getopt.h>
+#include <uuid/uuid.h>
 
 #include "kerncompat.h"
 #include "ioctl.h"
@@ -418,10 +419,10 @@ static int cmd_subvol_list(int argc, char **argv)
 
 	if (is_tab_result)
 		ret = btrfs_list_subvols_print(fd, filter_set, comparer_set,
-				BTRFS_LIST_LAYOUT_TABLE);
+				BTRFS_LIST_LAYOUT_TABLE, NULL);
 	else
 		ret = btrfs_list_subvols_print(fd, filter_set, comparer_set,
-				BTRFS_LIST_LAYOUT_DEFAULT);
+				BTRFS_LIST_LAYOUT_DEFAULT, NULL);
 	if (ret)
 		return 19;
 	return 0;
@@ -634,7 +635,7 @@ static int cmd_subvol_get_default(int argc, char **argv)
 	btrfs_list_setup_print_column(BTRFS_LIST_PATH);
 
 	ret = btrfs_list_subvols_print(fd, filter_set, NULL,
-		BTRFS_LIST_LAYOUT_DEFAULT);
+		BTRFS_LIST_LAYOUT_DEFAULT, NULL);
 	if (ret)
 		return 19;
 	return 0;
@@ -721,6 +722,153 @@ static int cmd_find_new(int argc, char **argv)
 	return 0;
 }
 
+static const char * const cmd_subvol_show_usage[] = {
+	"btrfs subvolume show <subvol-path>",
+	"Show more information of the subvolume",
+	NULL
+};
+
+static int cmd_subvol_show(int argc, char **argv)
+{
+	struct root_info get_ri;
+	struct btrfs_list_filter_set *filter_set;
+	char tstr[256];
+	char uuidparse[37];
+	char *fullpath = NULL, *svpath = NULL, *mnt = NULL;
+	char raw_prefix[] = "\t\t\t\t";
+	u64 sv_id, mntid;
+	int fd = -1, mntfd = -1;
+	int ret = -1;
+
+	if (check_argc_exact(argc, 2))
+		usage(cmd_subvol_show_usage);
+
+	fullpath = realpath(argv[1], 0);
+	if (!fullpath) {
+		fprintf(stderr, "ERROR: finding real path for '%s', %s\n",
+			argv[1], strerror(errno));
+		goto out;
+	}
+
+	ret = test_issubvolume(fullpath);
+	if (ret < 0) {
+		fprintf(stderr, "ERROR: error accessing '%s'\n", fullpath);
+		goto out;
+	}
+	if (!ret) {
+		fprintf(stderr, "ERROR: '%s' is not a subvolume\n", fullpath);
+		ret = -1;
+		goto out;
+	}
+
+	ret = find_mount_root(fullpath, &mnt);
+	if (ret < 0) {
+		fprintf(stderr, "ERROR: find_mount_root failed on %s: "
+				"%s\n", fullpath, strerror(-ret));
+		goto out;
+	}
+	ret = -1;
+	svpath = get_subvol_name(mnt, fullpath);
+
+	fd = open_file_or_dir(fullpath);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access '%s'\n", fullpath);
+		goto out;
+	}
+
+	sv_id = btrfs_list_get_path_rootid(fd);
+	if (sv_id < 0) {
+		fprintf(stderr, "ERROR: can't get rootid for '%s'\n",
+			fullpath);
+		goto out;
+	}
+
+	mntfd = open_file_or_dir(mnt);
+	if (mntfd < 0) {
+		fprintf(stderr, "ERROR: can't access '%s'\n", mnt);
+		goto out;
+	}
+
+	mntid = btrfs_list_get_path_rootid(mntfd);
+	if (mntid < 0) {
+		fprintf(stderr, "ERROR: can't get rootid for '%s'\n", mnt);
+		goto out;
+	}
+
+	if (sv_id == BTRFS_FS_TREE_OBJECTID) {
+		printf("%s is btrfs root\n", fullpath);
+		goto out;
+	}
+
+	memset(&get_ri, 0, sizeof(get_ri));
+	get_ri.root_id = sv_id;
+
+	if (btrfs_get_subvol(mntfd, &get_ri)) {
+		fprintf(stderr, "ERROR: can't find '%s'\n",
+			svpath);
+		goto out;
+	}
+
+	ret = 0;
+	/* print the info */
+	printf("%s\n", fullpath);
+	printf("\tName: \t\t\t%s\n", get_ri.name);
+
+	if (uuid_is_null(get_ri.uuid))
+		strcpy(uuidparse, "-");
+	else
+		uuid_unparse(get_ri.uuid, uuidparse);
+	printf("\tuuid: \t\t\t%s\n", uuidparse);
+
+	if (uuid_is_null(get_ri.puuid))
+		strcpy(uuidparse, "-");
+	else
+		uuid_unparse(get_ri.puuid, uuidparse);
+	printf("\tParent uuid: \t\t%s\n", uuidparse);
+
+	if (get_ri.otime)
+		strftime(tstr, 256, "%Y-%m-%d %X",
+			 localtime(&get_ri.otime));
+	else
+		strcpy(tstr, "-");
+	printf("\tCreation time: \t\t%s\n", tstr);
+
+	printf("\tObject ID: \t\t%llu\n", get_ri.root_id);
+	printf("\tGeneration (Gen): \t%llu\n", get_ri.gen);
+	printf("\tGen at creation: \t%llu\n", get_ri.ogen);
+	printf("\tParent: \t\t%llu\n", get_ri.ref_tree);
+	printf("\tTop Level: \t\t%llu\n", get_ri.top_id);
+
+	/* print the snapshots of the given subvol if any*/
+	printf("\tSnapshot(s):\n");
+	filter_set = btrfs_list_alloc_filter_set();
+	btrfs_list_setup_filter(&filter_set, BTRFS_LIST_FILTER_BY_PARENT,
+				get_ri.uuid);
+	btrfs_list_setup_print_column(BTRFS_LIST_PATH);
+	btrfs_list_subvols_print(fd, filter_set, NULL, BTRFS_LIST_LAYOUT_RAW,
+			raw_prefix);
+
+	/* clean up */
+	if (get_ri.path)
+		free(get_ri.path);
+	if (get_ri.name)
+		free(get_ri.name);
+	if (get_ri.full_path)
+		free(get_ri.full_path);
+
+out:
+	if (mntfd >= 0)
+		close(mntfd);
+	if (fd >= 0)
+		close(fd);
+	if (mnt)
+		free(mnt);
+	if (fullpath)
+		free(fullpath);
+
+	return ret;
+}
+
 const struct cmd_group subvolume_cmd_group = {
 	subvolume_cmd_group_usage, NULL, {
 		{ "create", cmd_subvol_create, cmd_subvol_create_usage, NULL, 0 },
@@ -732,6 +880,7 @@ const struct cmd_group subvolume_cmd_group = {
 		{ "set-default", cmd_subvol_set_default,
 			cmd_subvol_set_default_usage, NULL, 0 },
 		{ "find-new", cmd_find_new, cmd_find_new_usage, NULL, 0 },
+		{ "show", cmd_subvol_show, cmd_subvol_show_usage, NULL, 0 },
 		{ 0, 0, 0, 0, 0 }
 	}
 };
diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index d20e332..0008a06 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -17,6 +17,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBsubvolume get-default\fP\fI <path>\fP
 .PP
+\fBbtrfs\fP \fBsubvolume show\fP\fI <path>\fP
+.PP
 \fBbtrfs\fP \fBfilesystem defragment\fP -c[zlib|lzo] [-l \fIlen\fR] \
 [-s \fIstart\fR] [-t \fIsize\fR] -[vf] <\fIfile\fR>|<\fIdir\fR> \
 [<\fIfile\fR>|<\fIdir\fR>...]
@@ -158,6 +160,10 @@ Get the default subvolume of the filesystem \fI<path>\fR. The output format
 is similar to \fBsubvolume list\fR command.
 .TP
 
+\fBsubvolume show\fR\fI <path>\fR
+Show information of a given subvolume in the \fI<path>\fR.
+.TP
+
 \fBfilesystem defragment\fP -c[zlib|lzo] [-l \fIlen\fR] [-s \fIstart\fR] \
 [-t \fIsize\fR] -[vf] <\fIfile\fR>|<\fIdir\fR> [<\fIfile\fR>|<\fIdir\fR>...]
 
-- 
1.8.1.227.g44fe835