btrfs-progs: qgroups usability [corrected]

From: Jeff Mahoney <[email protected]>

This patch adds a new -W option to wait for a rescan without starting a new operation. This is useful for things like xfstests where we want do to do a "btrfs quota enable" and not continue until the subsequent rescan has finished.

In addition to documenting the new option in the man page, I've cleaned up the rescan entry to document the -w option a bit better.

Signed-off-by Jeff Mahoney <[email protected]>

---
 Documentation/btrfs-quota.asciidoc | 10 +++++++---
 cmds-quota.c                       | 21 +++++++++++++++------
 2 files changed, 22 insertions(+), 9 deletions(-)

Documentation/btrfs-quota.asciidoc +7 -3

index 85ebf729..0b64a69b 100644
@@ -238,15 +238,19 @@ Disable subvolume quota support for a filesystem.
 *enable* <path>::
 Enable subvolume quota support for a filesystem.
 
-*rescan* [-s] <path>::
+*rescan* [-s|-w|-W] <path>::
 Trash all qgroup numbers and scan the metadata again with the current config.
 +
 `Options`
 +
 -s::::
-show status of a running rescan operation.
+Show status of a running rescan operation.
+
 -w::::
-wait for rescan operation to finish(can be already in progress).
+Start rescan operation and wait until it has finished before exiting.  If a rescan is already running, wait until it finishes and then exit without starting a new one.
+
+-W::::
+Wait for rescan operation to finish and then exit.  If a rescan is not already running, exit silently.
 
 EXIT STATUS
 -----------

cmds-quota.c +7 -1

index 745889d1..fe6376ac 100644
@@ -120,14 +120,20 @@ static int cmd_quota_rescan(int argc, char **argv)
 	int wait_for_completion = 0;
 
 	while (1) {
-		int c = getopt(argc, argv, "sw");
+		int c = getopt(argc, argv, "swW");
 		if (c < 0)
 			break;
 		switch (c) {
 		case 's':
 			ioctlnum = BTRFS_IOC_QUOTA_RESCAN_STATUS;
 			break;
+		case 'W':
+			ioctlnum = 0;
+			wait_for_completion = 1;
+			break;
 		case 'w':
+			/* Reset it in case the user did both -W and -w */
+			ioctlnum = BTRFS_IOC_QUOTA_RESCAN;
 			wait_for_completion = 1;
 			break;
 		default:

cmds-quota.c +5 -3

 		return 1;
 	}
 

@@ -150,8 +157,10 @@ static int cmd_quota_rescan(int argc, char **argv)
 	if (fd < 0)
 		return 1;
 
-	ret = ioctl(fd, ioctlnum, &args);
-	e = errno;
+	if (ioctlnum) {
+		ret = ioctl(fd, ioctlnum, &args);
+		e = errno;
+	}
 
 	if (ioctlnum == BTRFS_IOC_QUOTA_RESCAN_STATUS) {
 		close_file_or_dir(fd, dirstream);

@@ -167,7 +176,7 @@ static int cmd_quota_rescan(int argc, char **argv)
 		return 0;
 	}
 
-	if (ret == 0) {
+	if (ioctlnum == BTRFS_IOC_QUOTA_RESCAN && ret == 0) {
 		printf("quota rescan started\n");
 		fflush(stdout);
 	} else if (ret < 0 && (!wait_for_completion || e != EINPROGRESS)) {

Quoted 5 lines · On 2.03.2018 20:46, [email protected] wrote:

From: Jeff Mahoney <[email protected]>

(quoted diff) +0 -0

@@ -135,8 +141,9 @@ static int cmd_quota_rescan(int argc, char **argv)
 		}
 	}
 

cmds-quota.c static int cmd_quota_rescan(int argc, char **argv) · line 146

Quoted 5 lines

cmds-quota.c +3 -2

-	if (ioctlnum != BTRFS_IOC_QUOTA_RESCAN && wait_for_completion) {
-		error("switch -w cannot be used with -s");
+	if (ioctlnum == BTRFS_IOC_QUOTA_RESCAN_STATUS && wait_for_completion) {
+		error("switch -%c cannot be used with -s",
+		      ioctlnum ? 'w' : 'W');

You can't really distinguish between w/W in this context, since ioctlnum will be RESCAN_STATUS. So just harcode the w/W in the text message itself?

From: Jeff Mahoney <[email protected]>

In print_single_qgroup_table we check the loop index against BTRFS_QGROUP_CHILD, but what we really mean is "last column." Since we have an enum value to indicate the last value, use that instead of assuming that BTRFS_QGROUP_CHILD is always last.

Signed-off-by Jeff Mahoney <[email protected]>

---
 qgroup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

qgroup.c +1 -1

index 11659e83..67bc0738 100644
@@ -267,7 +267,7 @@ static void print_single_qgroup_table(struct btrfs_qgroup *qgroup)
 			continue;
 		print_qgroup_column(qgroup, i);
 
-		if (i != BTRFS_QGROUP_CHILD)
+		if (i != BTRFS_QGROUP_ALL - 1)
 			printf(" ");
 	}
 	printf("\n");

From: Jeff Mahoney <[email protected]>

It's unlikely we're going to modify a pathname argument, so codify that and use const.

Signed-off-by Jeff Mahoney <[email protected]>

---
 chunk-recover.c | 4 ++--
 cmds-device.c   | 2 +-
 cmds-fi-usage.c | 6 +++---
 cmds-rescue.c   | 4 ++--
 send-utils.c    | 4 ++--
 5 files changed, 10 insertions(+), 10 deletions(-)

chunk-recover.c +2 -2

index 705bcf52..1d30db51 100644
@@ -1492,7 +1492,7 @@ out:
 	return ERR_PTR(ret);
 }
 
-static int recover_prepare(struct recover_control *rc, char *path)
+static int recover_prepare(struct recover_control *rc, const char *path)
 {
 	int ret;
 	int fd;

@@ -2296,7 +2296,7 @@ static void validate_rebuild_chunks(struct recover_control *rc)
 /*
  * Return 0 when successful, < 0 on error and > 0 if aborted by user
  */
-int btrfs_recover_chunk_tree(char *path, int verbose, int yes)
+int btrfs_recover_chunk_tree(const char *path, int verbose, int yes)
 {
 	int ret = 0;
 	struct btrfs_root *root = NULL;

cmds-device.c +0 -0

index 86459d1b..a49c9d9d 100644

cmds-device.c +0 -0

 {
 	int i;
 	int ret = 0;> diff --git a/cmds-fi-usage.c b/cmds-fi-usage.c

index de7ad668..9a1c76ab 100644

cmds-fi-usage.c +3 -3

@@ -227,7 +227,7 @@ static int cmp_btrfs_ioctl_space_info(const void *a, const void *b)
 /*
  * This function load all the information about the space usage
  */
-static struct btrfs_ioctl_space_args *load_space_info(int fd, char *path)
+static struct btrfs_ioctl_space_args *load_space_info(int fd, const char *path)
 {
 	struct btrfs_ioctl_space_args *sargs = NULL, *sargs_orig = NULL;
 	int ret, count;

@@ -305,7 +305,7 @@ static void get_raid56_used(struct chunk_info *chunks, int chunkcount,
 #define	MIN_UNALOCATED_THRESH	SZ_16M
 static int print_filesystem_usage_overall(int fd, struct chunk_info *chunkinfo,
 		int chunkcount, struct device_info *devinfo, int devcount,
-		char *path, unsigned unit_mode)
+		const char *path, unsigned unit_mode)
 {
 	struct btrfs_ioctl_space_args *sargs = NULL;
 	int i;

@@ -931,7 +931,7 @@ static void _cmd_filesystem_usage_linear(unsigned unit_mode,
 static int print_filesystem_usage_by_chunk(int fd,
 		struct chunk_info *chunkinfo, int chunkcount,
 		struct device_info *devinfo, int devcount,
-		char *path, unsigned unit_mode, int tabular)
+		const char *path, unsigned unit_mode, int tabular)
 {
 	struct btrfs_ioctl_space_args *sargs;
 	int ret = 0;

cmds-rescue.c +0 -0

index c40088ad..c61145bc 100644

cmds-rescue.c +1 -0

+int btrfs_recover_superblocks(const char *path, int verbose, int yes);
 
 static const char * const cmd_rescue_chunk_recover_usage[] = {
 	"btrfs rescue chunk-recover [options] <device>",

send-utils.c +0 -0

index b5289e76..8ce94de1 100644

send-utils.c +0 -0

 static int btrfs_get_root_id_by_sub_path(int mnt_fd, const char *sub_path,
 					 u64 *root_id)
 

Quoted 44 lines · On 2.03.2018 20:46, [email protected] wrote:

From: Jeff Mahoney <[email protected]>

It's unlikely we're going to modify a pathname argument, so codify that and use const.

Signed-off-by Jeff Mahoney <[email protected]>

---
 chunk-recover.c | 4 ++--
 cmds-device.c   | 2 +-
 cmds-fi-usage.c | 6 +++---
 cmds-rescue.c   | 4 ++--
 send-utils.c    | 4 ++--
 5 files changed, 10 insertions(+), 10 deletions(-)

chunk-recover.c +2 -2

index 705bcf52..1d30db51 100644
@@ -1492,7 +1492,7 @@ out:
 	return ERR_PTR(ret);
 }
 
-static int recover_prepare(struct recover_control *rc, char *path)
+static int recover_prepare(struct recover_control *rc, const char *path)
 {
 	int ret;
 	int fd;

@@ -2296,7 +2296,7 @@ static void validate_rebuild_chunks(struct recover_control *rc)
 /*
  * Return 0 when successful, < 0 on error and > 0 if aborted by user
  */
-int btrfs_recover_chunk_tree(char *path, int verbose, int yes)
+int btrfs_recover_chunk_tree(const char *path, int verbose, int yes)
 {
 	int ret = 0;
 	struct btrfs_root *root = NULL;

cmds-device.c +0 -0

index 86459d1b..a49c9d9d 100644
@@ -526,7 +526,7 @@ static const char * const cmd_device_usage_usage[] = {
 	NULL
 };
 

cmds-device.c static const char * const cmd_device_usage_usage[] = { · line 529

Quoted 2 lines

cmds-device.c +1 -1

-static int _cmd_device_usage(int fd, char *path, unsigned unit_mode)
+static int _cmd_device_usage(int fd, const char *path, unsigned unit_mode)

Actually the path parameter is not used in this function at all, I'd say just remove it.

Quoted 41 lines

cmds-device.c +0 -0

 {
 	int i;
 	int ret = 0;> diff --git a/cmds-fi-usage.c b/cmds-fi-usage.c

index de7ad668..9a1c76ab 100644

cmds-fi-usage.c +3 -3

@@ -227,7 +227,7 @@ static int cmp_btrfs_ioctl_space_info(const void *a, const void *b)
 /*
  * This function load all the information about the space usage
  */
-static struct btrfs_ioctl_space_args *load_space_info(int fd, char *path)
+static struct btrfs_ioctl_space_args *load_space_info(int fd, const char *path)
 {
 	struct btrfs_ioctl_space_args *sargs = NULL, *sargs_orig = NULL;
 	int ret, count;

@@ -305,7 +305,7 @@ static void get_raid56_used(struct chunk_info *chunks, int chunkcount,
 #define	MIN_UNALOCATED_THRESH	SZ_16M
 static int print_filesystem_usage_overall(int fd, struct chunk_info *chunkinfo,
 		int chunkcount, struct device_info *devinfo, int devcount,
-		char *path, unsigned unit_mode)
+		const char *path, unsigned unit_mode)
 {
 	struct btrfs_ioctl_space_args *sargs = NULL;
 	int i;

@@ -931,7 +931,7 @@ static void _cmd_filesystem_usage_linear(unsigned unit_mode,
 static int print_filesystem_usage_by_chunk(int fd,
 		struct chunk_info *chunkinfo, int chunkcount,
 		struct device_info *devinfo, int devcount,
-		char *path, unsigned unit_mode, int tabular)
+		const char *path, unsigned unit_mode, int tabular)
 {
 	struct btrfs_ioctl_space_args *sargs;
 	int ret = 0;

cmds-rescue.c +0 -0

index c40088ad..c61145bc 100644
@@ -32,8 +32,8 @@ static const char * const rescue_cmd_group_usage[] = {
 	NULL
 };
 

cmds-rescue.c static const char * const rescue_cmd_group_usage[] = { · line 35

Quoted 3 lines

cmds-rescue.c +1 -2

-int btrfs_recover_chunk_tree(char *path, int verbose, int yes);
-int btrfs_recover_superblocks(char *path, int verbose, int yes);
+int btrfs_recover_chunk_tree(const char *path, int verbose, int yes);

That path argument is being passed to recover_prepare which can alo use a const to its path parameter

Quoted 12 lines

cmds-rescue.c +1 -0

+int btrfs_recover_superblocks(const char *path, int verbose, int yes);
 
 static const char * const cmd_rescue_chunk_recover_usage[] = {
 	"btrfs rescue chunk-recover [options] <device>",

send-utils.c +0 -0

index b5289e76..8ce94de1 100644
@@ -28,8 +28,8 @@
 #include "ioctl.h"
 #include "btrfs-list.h"
 

send-utils.c line 32

Quoted 4 lines

send-utils.c +2 -2

-static int btrfs_subvolid_resolve_sub(int fd, char *path, size_t *path_len,
-				      u64 subvol_id);
+static int btrfs_subvolid_resolve_sub(int fd, char *path,
+				      size_t *path_len, u64 subvol_id);

This seems like an unrelated change. As a matter of fact btrfs_subvolid_resolve_sub is used only by btrfs_subvolid_resolve. So if you move the latter after the former then you can drop the declaration at the beginning of the file altogether.

From: Jeff Mahoney <[email protected]>

The btrfs qgroup show command currently only exports qgroup IDs, forcing the user to resolve which subvolume each corresponds to.

This patch adds pathname resolution to qgroup show so that when the -P option is used, the last column contains the pathname of the root of the subvolume it describes. In the case of nested qgroups, it will show the number of member qgroups or the paths of the members if the -v option is used.

Pathname can also be used as a sort parameter.

Signed-off-by Jeff Mahoney <[email protected]>

---
 Documentation/btrfs-qgroup.asciidoc |   4 +
 cmds-qgroup.c                       |  17 ++++-
 kerncompat.h                        |   1 +
 qgroup.c                            | 142 ++++++++++++++++++++++++++++++++----
 qgroup.h                            |   4 +-
 utils.c                             |  22 ++++--
 utils.h                             |   2 +
 7 files changed, 166 insertions(+), 26 deletions(-)

Documentation/btrfs-qgroup.asciidoc +4 -0

index 3108457c..360b3269 100644
@@ -97,10 +97,14 @@ print child qgroup id.
 print limit of referenced size of qgroup.
 -e::::
 print limit of exclusive size of qgroup.
+-P::::
+print pathname to the root of the subvolume managed by qgroup.  For nested qgroups, the number of members will be printed unless -v is specified.
 -F::::
 list all qgroups which impact the given path(include ancestral qgroups)
 -f::::
 list all qgroups which impact the given path(exclude ancestral qgroups)
+-v::::
+Be more verbose.  Print pathnames of member qgroups when nested.
 --raw::::
 raw numbers in bytes, without the 'B' suffix.
 --human-readable::::

cmds-qgroup.c +0 -0

index 48686436..94cd0fd3 100644

cmds-qgroup.c +12 -3

 	HELPINFO_UNITS_LONG,
-	"--sort=qgroupid,rfer,excl,max_rfer,max_excl",
+	"--sort=qgroupid,rfer,excl,max_rfer,max_excl,pathname",
 	"               list qgroups sorted by specified items",
 	"               you can use '+' or '-' in front of each item.",
 	"               (+:ascending, -:descending, ascending default)",

@@ -299,6 +301,7 @@ static int cmd_qgroup_show(int argc, char **argv)
 	int filter_flag = 0;
 	unsigned unit_mode;
 	int sync = 0;
+	bool verbose = false;
 
 	struct btrfs_qgroup_comparer_set *comparer_set;
 	struct btrfs_qgroup_filter_set *filter_set;

@@ -316,10 +319,11 @@ static int cmd_qgroup_show(int argc, char **argv)
 		static const struct option long_options[] = {
 			{"sort", required_argument, NULL, GETOPT_VAL_SORT},
 			{"sync", no_argument, NULL, GETOPT_VAL_SYNC},
+			{"verbose", no_argument, NULL, 'v'},
 			{ NULL, 0, NULL, 0 }
 		};
 
-		c = getopt_long(argc, argv, "pcreFf", long_options, NULL);
+		c = getopt_long(argc, argv, "pPcreFfv", long_options, NULL);
 		if (c < 0)
 			break;
 		switch (c) {

@@ -327,6 +331,10 @@ static int cmd_qgroup_show(int argc, char **argv)
 			btrfs_qgroup_setup_print_column(
 				BTRFS_QGROUP_PARENT);
 			break;
+		case 'P':
+			btrfs_qgroup_setup_print_column(
+				BTRFS_QGROUP_PATHNAME);
+			break;
 		case 'c':
 			btrfs_qgroup_setup_print_column(
 				BTRFS_QGROUP_CHILD);

@@ -354,6 +362,9 @@ static int cmd_qgroup_show(int argc, char **argv)
 		case GETOPT_VAL_SYNC:
 			sync = 1;
 			break;
+		case 'v':
+			verbose = true;
+			break;
 		default:
 			usage(cmd_qgroup_show_usage);
 		}

@@ -394,7 +405,7 @@ static int cmd_qgroup_show(int argc, char **argv)
 					BTRFS_QGROUP_FILTER_PARENT,
 					qgroupid);
 	}
-	ret = btrfs_show_qgroups(fd, filter_set, comparer_set);
+	ret = btrfs_show_qgroups(fd, filter_set, comparer_set, verbose);
 	close_file_or_dir(fd, dirstream);
 	free(filter_set);
 	free(comparer_set);

kerncompat.h +1 -0

index fa96715f..f97495ee 100644
@@ -29,6 +29,7 @@
 #include <stddef.h>
 #include <linux/types.h>
 #include <stdint.h>
+#include <stdbool.h>
 
 #include <features.h>
 

qgroup.c +10 -0

index 67bc0738..83918134 100644
@@ -40,6 +40,9 @@ struct btrfs_qgroup {
 	struct rb_node all_parent_node;
 	u64 qgroupid;
 
+	/* NULL for qgroups with level > 0 */
+	const char *pathname;
+
 	/*
 	 * info_item
 	 */

@@ -133,6 +136,13 @@ static struct {
 		.unit_mode	= 0,
 		.max_len	= 5,
 	},
+	{
+		.name		= "pathname",
+		.column_name	= "pathname",
+		.need_print	= 0,
+		.unit_mode	= 0,
+		.max_len	= 10,
+	},
 	{
 		.name		= NULL,
 		.column_name	= NULL,

qgroup.c +86 -4

+				else
+					printf("%llu/%llu", level, sid);
+			}
+			count++;
+		}
+		if (!count)
+			fputs("<empty>", stdout);
+		else if (!verbose)
+			printf("<%u member qgroup%c>", count,
+			       count != 1 ? 's' : '\0');
+	} else if (qgroup->pathname)
+		fputs(qgroup->pathname, stdout);
+	else
+		fputs("<missing>", stdout);
+}
+
 static void print_qgroup_column(struct btrfs_qgroup *qgroup,
-				enum btrfs_qgroup_column_enum column)
+				enum btrfs_qgroup_column_enum column,
+				bool verbose)
 {
 	int len;
 	int unit_mode = btrfs_qgroup_columns[column].unit_mode;

@@ -253,19 +297,22 @@ static void print_qgroup_column(struct btrfs_qgroup *qgroup,
 		len = print_child_column(qgroup);
 		print_qgroup_column_add_blank(BTRFS_QGROUP_CHILD, len);
 		break;
+	case BTRFS_QGROUP_PATHNAME:
+		print_pathname_column(qgroup, verbose);
+		break;
 	default:
 		break;
 	}
 }
 
-static void print_single_qgroup_table(struct btrfs_qgroup *qgroup)
+static void print_single_qgroup_table(struct btrfs_qgroup *qgroup, bool verbose)
 {
 	int i;
 
 	for (i = 0; i < BTRFS_QGROUP_ALL; i++) {
 		if (!btrfs_qgroup_columns[i].need_print)
 			continue;
-		print_qgroup_column(qgroup, i);
+		print_qgroup_column(qgroup, i, verbose);
 
 		if (i != BTRFS_QGROUP_ALL - 1)
 			printf(" ");

@@ -338,6 +385,47 @@ static int comp_entry_with_qgroupid(struct btrfs_qgroup *entry1,
 	return is_descending ? -ret : ret;
 }
 
+/* Sorts first-level qgroups by pathname and nested qgroups by qgroupid */
+static int comp_entry_with_pathname(struct btrfs_qgroup *entry1,
+				    struct btrfs_qgroup *entry2,
+				    int is_descending)
+{
+	int ret = 0;
+	const char *p1 = entry1->pathname;
+	const char *p2 = entry2->pathname;
+
+	u64 level1 = btrfs_qgroup_level(entry1->qgroupid);
+	u64 level2 = btrfs_qgroup_level(entry2->qgroupid);
+
+	if (level1 != level2) {
+		if (entry1->qgroupid > entry2->qgroupid)
+			ret = 1;
+		else if (entry1->qgroupid < entry2->qgroupid)
+			ret = -1;
+	}
+
+	if (ret)
+		goto out;
+
+	while (*p1 && *p2) {
+		if (*p1 != *p2)
+			break;
+		p1++;
+		p2++;
+	}
+
+	if (*p1 == '/')
+		ret = 1;
+	else if (*p2 == '/')
+	      ret = -1;
+	else if (*p1 > *p2)
+	      ret = 1;
+	else if (*p1 < *p2)
+		ret = -1;
+out:
+	return is_descending ? -ret : ret;
+}
+
 static int comp_entry_with_rfer(struct btrfs_qgroup *entry1,
 				struct btrfs_qgroup *entry2,
 				int is_descending)

@@ -404,6 +492,7 @@ static int comp_entry_with_max_excl(struct btrfs_qgroup *entry1,
 
 static btrfs_qgroup_comp_func all_comp_funcs[] = {
 	[BTRFS_QGROUP_COMP_QGROUPID]	= comp_entry_with_qgroupid,
+	[BTRFS_QGROUP_COMP_PATHNAME]	= comp_entry_with_pathname,
 	[BTRFS_QGROUP_COMP_RFER]	= comp_entry_with_rfer,
 	[BTRFS_QGROUP_COMP_EXCL]	= comp_entry_with_excl,
 	[BTRFS_QGROUP_COMP_MAX_RFER]	= comp_entry_with_max_rfer,

@@ -412,6 +501,7 @@ static btrfs_qgroup_comp_func all_comp_funcs[] = {
 
 static char *all_sort_items[] = {
 	[BTRFS_QGROUP_COMP_QGROUPID]	= "qgroupid",
+	[BTRFS_QGROUP_COMP_PATHNAME]	= "pathname",
 	[BTRFS_QGROUP_COMP_RFER]	= "rfer",
 	[BTRFS_QGROUP_COMP_EXCL]	= "excl",
 	[BTRFS_QGROUP_COMP_MAX_RFER]	= "max_rfer",

@@ -578,6 +668,25 @@ static struct btrfs_qgroup *qgroup_tree_search(struct qgroup_lookup *root_tree,
 	return NULL;
 }
 
+static const char *qgroup_pathname(int fd, u64 qgroupid)
+{
+	struct root_info root_info;
+	int ret;
+	char *pathname;
+
+	ret = get_subvol_info_by_rootid_fd(fd, &root_info, qgroupid);
+	if (ret)
+		return NULL;
+
+	ret = asprintf(&pathname, "%s%s",
+		       root_info.full_path[0] == '/' ? "" : "/",
+		       root_info.full_path);
+	if (ret < 0)
+		return NULL;
+
+	return pathname;
+}
+
 /*
  * Lookup or insert btrfs_qgroup into qgroup_lookup.
  *

@@ -588,7 +697,7 @@ static struct btrfs_qgroup *qgroup_tree_search(struct qgroup_lookup *root_tree,
  * Return the pointer to the btrfs_qgroup if found or if inserted successfully.
  * Return ERR_PTR if any error occurred.
  */
-static struct btrfs_qgroup *get_or_add_qgroup(
+static struct btrfs_qgroup *get_or_add_qgroup(int fd,
 		struct qgroup_lookup *qgroup_lookup, u64 qgroupid)
 {
 	struct btrfs_qgroup *bq;

qgroup.c +12 -11

 	ret = qgroup_tree_insert(qgroup_lookup, bq);
 	if (ret) {
 		error("failed to insert %llu into tree: %s",

@@ -619,12 +730,12 @@ static struct btrfs_qgroup *get_or_add_qgroup(
 	return bq;
 }
 
-static int update_qgroup_info(struct qgroup_lookup *qgroup_lookup, u64 qgroupid,
-			      struct btrfs_qgroup_info_item *info)
+static int update_qgroup_info(int fd, struct qgroup_lookup *qgroup_lookup,
+			      u64 qgroupid, struct btrfs_qgroup_info_item *info)
 {
 	struct btrfs_qgroup *bq;
 
-	bq = get_or_add_qgroup(qgroup_lookup, qgroupid);
+	bq = get_or_add_qgroup(fd, qgroup_lookup, qgroupid);
 	if (IS_ERR_OR_NULL(bq))
 		return PTR_ERR(bq);
 

@@ -637,13 +748,13 @@ static int update_qgroup_info(struct qgroup_lookup *qgroup_lookup, u64 qgroupid,
 	return 0;
 }
 
-static int update_qgroup_limit(struct qgroup_lookup *qgroup_lookup,
+static int update_qgroup_limit(int fd, struct qgroup_lookup *qgroup_lookup,
 			       u64 qgroupid,
 			       struct btrfs_qgroup_limit_item *limit)
 {
 	struct btrfs_qgroup *bq;
 
-	bq = get_or_add_qgroup(qgroup_lookup, qgroupid);
+	bq = get_or_add_qgroup(fd, qgroup_lookup, qgroupid);
 	if (IS_ERR_OR_NULL(bq))
 		return PTR_ERR(bq);
 

@@ -1107,7 +1218,7 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 				info = (struct btrfs_qgroup_info_item *)
 				       (args.buf + off);
 
-				ret = update_qgroup_info(qgroup_lookup,
+				ret = update_qgroup_info(fd, qgroup_lookup,
 							 qgroupid, info);
 				break;
 			case BTRFS_QGROUP_LIMIT_KEY:

@@ -1115,7 +1226,7 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 				limit = (struct btrfs_qgroup_limit_item *)
 					(args.buf + off);
 
-				ret = update_qgroup_limit(qgroup_lookup,
+				ret = update_qgroup_limit(fd, qgroup_lookup,
 							  qgroupid, limit);
 				break;
 			case BTRFS_QGROUP_RELATION_KEY:

@@ -1159,7 +1270,7 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 	return ret;
 }
 
-static void print_all_qgroups(struct qgroup_lookup *qgroup_lookup)
+static void print_all_qgroups(struct qgroup_lookup *qgroup_lookup, bool verbose)
 {
 
 	struct rb_node *n;

@@ -1170,14 +1281,15 @@ static void print_all_qgroups(struct qgroup_lookup *qgroup_lookup)
 	n = rb_first(&qgroup_lookup->root);
 	while (n) {
 		entry = rb_entry(n, struct btrfs_qgroup, sort_node);
-		print_single_qgroup_table(entry);
+		print_single_qgroup_table(entry, verbose);
 		n = rb_next(n);
 	}
 }
 
 int btrfs_show_qgroups(int fd,
 		       struct btrfs_qgroup_filter_set *filter_set,
-		       struct btrfs_qgroup_comparer_set *comp_set)
+		       struct btrfs_qgroup_comparer_set *comp_set,
+		       bool verbose)
 {
 
 	struct qgroup_lookup qgroup_lookup;

@@ -1189,7 +1301,7 @@ int btrfs_show_qgroups(int fd,
 		return ret;
 	__filter_and_sort_qgroups(&qgroup_lookup, &sort_tree,
 				  filter_set, comp_set);
-	print_all_qgroups(&sort_tree);
+	print_all_qgroups(&sort_tree, verbose);
 
 	__free_all_qgroups(&qgroup_lookup);
 	return ret;

qgroup.h +3 -1

index 875fbdf3..f7ab7de5 100644
@@ -59,11 +59,13 @@ enum btrfs_qgroup_column_enum {
 	BTRFS_QGROUP_MAX_EXCL,
 	BTRFS_QGROUP_PARENT,
 	BTRFS_QGROUP_CHILD,
+	BTRFS_QGROUP_PATHNAME,
 	BTRFS_QGROUP_ALL,
 };
 
 enum btrfs_qgroup_comp_enum {
 	BTRFS_QGROUP_COMP_QGROUPID,
+	BTRFS_QGROUP_COMP_PATHNAME,
 	BTRFS_QGROUP_COMP_RFER,
 	BTRFS_QGROUP_COMP_EXCL,
 	BTRFS_QGROUP_COMP_MAX_RFER,

@@ -80,7 +82,7 @@ enum btrfs_qgroup_filter_enum {
 int btrfs_qgroup_parse_sort_string(const char *opt_arg,
 				struct btrfs_qgroup_comparer_set **comps);
 int btrfs_show_qgroups(int fd, struct btrfs_qgroup_filter_set *,
-		       struct btrfs_qgroup_comparer_set *);
+		       struct btrfs_qgroup_comparer_set *, bool verbose);
 void btrfs_qgroup_setup_print_column(enum btrfs_qgroup_column_enum column);
 void btrfs_qgroup_setup_units(unsigned unit_mode);
 struct btrfs_qgroup_filter_set *btrfs_qgroup_alloc_filter_set(void);

utils.c +15 -7

index e9cb3a82..68202142 100644
@@ -2556,15 +2556,9 @@ out:
 	return ret;
 }
 
-int get_subvol_info_by_rootid(const char *mnt, struct root_info *get_ri, u64 r_id)
+int get_subvol_info_by_rootid_fd(int fd, struct root_info *get_ri, u64 r_id)
 {
-	int fd;
 	int ret;
-	DIR *dirstream = NULL;
-
-	fd = btrfs_open_dir(mnt, &dirstream, 1);
-	if (fd < 0)
-		return -EINVAL;
 
 	memset(get_ri, 0, sizeof(*get_ri));
 	get_ri->root_id = r_id;

@@ -2574,6 +2568,20 @@ int get_subvol_info_by_rootid(const char *mnt, struct root_info *get_ri, u64 r_i
 	else
 		ret = btrfs_get_subvol(fd, get_ri);
 
+	return ret;
+}
+
+int get_subvol_info_by_rootid(const char *mnt, struct root_info *get_ri, u64 r_id)
+{
+	int fd;
+	int ret;
+	DIR *dirstream = NULL;
+
+	fd = btrfs_open_dir(mnt, &dirstream, 1);
+	if (fd < 0)
+		return -EINVAL;
+
+	ret = get_subvol_info_by_rootid_fd(fd, get_ri, r_id);
 	if (ret)
 		error("can't find rootid '%llu' on '%s': %d", r_id, mnt, ret);
 

utils.h +2 -0

index b871c9ff..722d3c48 100644
@@ -154,6 +154,8 @@ int test_isdir(const char *path);
 
 const char *subvol_strip_mountpoint(const char *mnt, const char *full_path);
 int get_subvol_info(const char *fullpath, struct root_info *get_ri);
+int get_subvol_info_by_rootid_fd(int fd, struct root_info *get_ri,
+				 u64 rootid_arg);
 int get_subvol_info_by_rootid(const char *mnt, struct root_info *get_ri,
 							u64 rootid_arg);
 int get_subvol_info_by_uuid(const char *mnt, struct root_info *get_ri,

cmds-qgroup.c static const char * const cmd_qgroup_show_usage[] = { · line 284

Quoted 10 lines · On 2018年03月03日 02:47, [email protected] wrote:

cmds-qgroup.c +2 -0

index 48686436..94cd0fd3 100644
@@ -280,8 +280,10 @@ static const char * const cmd_qgroup_show_usage[] = {
 	"               (including ancestral qgroups)",
 	"-f             list all qgroups which impact the given path",
 	"               (excluding ancestral qgroups)",
+	"-P             print first-level qgroups using pathname",
+	"-v             verbose, prints all nested subvolumes",

Did you mean the subvolume paths of all children qgroups?

Quoted 15 lines

cmds-qgroup.c +1 -1

 	HELPINFO_UNITS_LONG,
-	"--sort=qgroupid,rfer,excl,max_rfer,max_excl",
+	"--sort=qgroupid,rfer,excl,max_rfer,max_excl,pathname",
 	"               list qgroups sorted by specified items",
 	"               you can use '+' or '-' in front of each item.",
 	"               (+:ascending, -:descending, ascending default)",

qgroup.c +0 -0

index 67bc0738..83918134 100644
@@ -210,8 +220,42 @@ static void print_qgroup_column_add_blank(enum btrfs_qgroup_column_enum column,
 		printf(" ");
 }
 

qgroup.c static void print_qgroup_column_add_blank(enum btrfs_qgroup_column_enum column, · line 229

Quoted 7 lines

qgroup.c +7 -0

+void print_pathname_column(struct btrfs_qgroup *qgroup, bool verbose)
+{
+	struct btrfs_qgroup_list *list = NULL;
+
+	fputs("  ", stdout);
+	if (btrfs_qgroup_level(qgroup->qgroupid) > 0) {
+		int count = 0;

Newline after declaration please.

And declaration in if() {} block doesn't pass checkpath IIRC.

qgroup.c static void print_qgroup_column_add_blank(enum btrfs_qgroup_column_enum column, · line 233

Quoted 4 lines

qgroup.c +4 -0

+		list_for_each_entry(list, &qgroup->qgroups,
+				    next_qgroup) {
+			if (verbose) {
+				struct btrfs_qgroup *member = list->qgroup;

Same coding style problem here.

qgroup.c static void print_qgroup_column_add_blank(enum btrfs_qgroup_column_enum column, · line 239

Quoted 6 lines

qgroup.c +6 -0

+				u64 level = btrfs_qgroup_level(member->qgroupid);
+				u64 sid = btrfs_qgroup_subvid(member->qgroupid);
+				if (count)
+					fputs(" ", stdout);
+				if (btrfs_qgroup_level(member->qgroupid) == 0)
+					fputs(member->pathname, stdout);

What about checking member->pathname before outputting? As it could be missing.

qgroup.c static struct btrfs_qgroup *qgroup_tree_search(struct qgroup_lookup *root_tree, · line 677

Quoted 7 lines

qgroup.c +7 -0

+static const char *qgroup_pathname(int fd, u64 qgroupid)
+{
+	struct root_info root_info;
+	int ret;
+	char *pathname;
+
+	ret = get_subvol_info_by_rootid_fd(fd, &root_info, qgroupid);

Quoted 28 lines

qgroup.c +13 -1

+	if (ret)
+		return NULL;
+
+	ret = asprintf(&pathname, "%s%s",
+		       root_info.full_path[0] == '/' ? "" : "/",
+		       root_info.full_path);
+	if (ret < 0)
+		return NULL;
+
+	return pathname;
+}
+
 /*
  * Lookup or insert btrfs_qgroup into qgroup_lookup.
  *

@@ -588,7 +697,7 @@ static struct btrfs_qgroup *qgroup_tree_search(struct qgroup_lookup *root_tree,
  * Return the pointer to the btrfs_qgroup if found or if inserted successfully.
  * Return ERR_PTR if any error occurred.
  */
-static struct btrfs_qgroup *get_or_add_qgroup(
+static struct btrfs_qgroup *get_or_add_qgroup(int fd,
 		struct qgroup_lookup *qgroup_lookup, u64 qgroupid)
 {
 	struct btrfs_qgroup *bq;

@@ -608,6 +717,8 @@ static struct btrfs_qgroup *get_or_add_qgroup(
 	INIT_LIST_HEAD(&bq->qgroups);
 	INIT_LIST_HEAD(&bq->members);
 

qgroup.c static struct btrfs_qgroup *get_or_add_qgroup( · line 721

Quoted 2 lines

qgroup.c +2 -0

+	bq->pathname = qgroup_pathname(fd, qgroupid);
+

Here qgroup_pathname() will allocate memory, but no one is freeing this memory.

The cleaner should be in __free_btrfs_qgroup() but there is no modification to that function.

From: Jeff Mahoney <[email protected]>

We use structures to pass the info and limit from the kernel as items but store the individual values separately in btrfs_qgroup. We already have a btrfs_qgroup_limit structure that's used for setting the limit.

This patch introduces a btrfs_qgroup_info structure and uses that and btrfs_qgroup_limit in btrfs_qgroup.

Signed-off-by Jeff Mahoney <[email protected]>

From: Jeff Mahoney <[email protected]>

The only mechanism we have in the progs for searching qgroups is to load all of them and filter the results. This works for qgroup show but to add quota information to 'btrfs subvoluem show' it's pretty wasteful.

This patch splits out setting up the search and performing the search so we can search for a single qgroupid more easily.

Signed-off-by Jeff Mahoney <[email protected]>

---
 qgroup.c | 98 +++++++++++++++++++++++++++++++++++++++++++++-------------------
 qgroup.h |  7 +++++
 2 files changed, 77 insertions(+), 28 deletions(-)

qgroup.c +33 -27

index b1be3311..2d0a6947 100644
@@ -1146,11 +1146,11 @@ static inline void print_status_flag_warning(u64 flags)
 		warning("qgroup data inconsistent, rescan recommended");
 }
 
-static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
+static int __qgroups_search(int fd, struct btrfs_ioctl_search_args *args,
+			    struct qgroup_lookup *qgroup_lookup)
 {
 	int ret;
-	struct btrfs_ioctl_search_args args;
-	struct btrfs_ioctl_search_key *sk = &args.key;
+	struct btrfs_ioctl_search_key *sk = &args->key;
 	struct btrfs_ioctl_search_header *sh;
 	unsigned long off = 0;
 	unsigned int i;

@@ -1161,30 +1161,12 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 	u64 qgroupid;
 	u64 qgroupid1;
 
-	memset(&args, 0, sizeof(args));
-
-	sk->tree_id = BTRFS_QUOTA_TREE_OBJECTID;
-	sk->max_type = BTRFS_QGROUP_RELATION_KEY;
-	sk->min_type = BTRFS_QGROUP_STATUS_KEY;
-	sk->max_objectid = (u64)-1;
-	sk->max_offset = (u64)-1;
-	sk->max_transid = (u64)-1;
-	sk->nr_items = 4096;
-
 	qgroup_lookup_init(qgroup_lookup);
 
 	while (1) {
-		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, args);
 		if (ret < 0) {
-			if (errno == ENOENT) {
-				error("can't list qgroups: quotas not enabled");
-				ret = -ENOTTY;
-			} else {
-				error("can't list qgroups: %s",
-				       strerror(errno));
-				ret = -errno;
-			}
-
+			ret = -errno;
 			break;
 		}
 

@@ -1198,14 +1180,14 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 		 * read the root_ref item it contains
 		 */
 		for (i = 0; i < sk->nr_items; i++) {
-			sh = (struct btrfs_ioctl_search_header *)(args.buf +
+			sh = (struct btrfs_ioctl_search_header *)(args->buf +
 								  off);
 			off += sizeof(*sh);
 
 			switch (btrfs_search_header_type(sh)) {
 			case BTRFS_QGROUP_STATUS_KEY:
 				si = (struct btrfs_qgroup_status_item *)
-				     (args.buf + off);
+				     (args->buf + off);
 				flags = btrfs_stack_qgroup_status_flags(si);
 
 				print_status_flag_warning(flags);

@@ -1213,7 +1195,7 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 			case BTRFS_QGROUP_INFO_KEY:
 				qgroupid = btrfs_search_header_offset(sh);
 				info = (struct btrfs_qgroup_info_item *)
-				       (args.buf + off);
+				       (args->buf + off);
 
 				ret = update_qgroup_info(fd, qgroup_lookup,
 							 qgroupid, info);

@@ -1221,7 +1203,7 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 			case BTRFS_QGROUP_LIMIT_KEY:
 				qgroupid = btrfs_search_header_offset(sh);
 				limit = (struct btrfs_qgroup_limit_item *)
-					(args.buf + off);
+					(args->buf + off);
 
 				ret = update_qgroup_limit(fd, qgroup_lookup,
 							  qgroupid, limit);

@@ -1267,6 +1249,66 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 	return ret;
 }
 
+static int qgroups_search_all(int fd, struct qgroup_lookup *qgroup_lookup)
+{
+	struct btrfs_ioctl_search_args args = {
+		.key = {
+			.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
+			.max_type = BTRFS_QGROUP_RELATION_KEY,
+			.min_type = BTRFS_QGROUP_STATUS_KEY,
+			.max_objectid = (u64)-1,
+			.max_offset = (u64)-1,
+			.max_transid = (u64)-1,
+			.nr_items = 4096,
+		},
+	};
+	int ret;
+
+	ret = __qgroups_search(fd, &args, qgroup_lookup);
+	if (ret == -ENOTTY)
+		error("can't list qgroups: quotas not enabled");
+	else if (ret < 0)
+		error("can't list qgroups: %s", strerror(-ret));
+	return ret;
+}
+
+int btrfs_qgroup_query(int fd, u64 qgroupid, struct btrfs_qgroup_stats *stats)

qgroup.c +27 -1

+		},
+	};
+	struct qgroup_lookup qgroup_lookup;
+	struct btrfs_qgroup *qgroup;
+	struct rb_node *n;
+	int ret;
+
+	ret = __qgroups_search(fd, &args, &qgroup_lookup);
+	if (ret < 0)
+		return ret;
+
+	ret = -ENODATA;
+	n = rb_first(&qgroup_lookup.root);
+	if (n) {
+		qgroup = rb_entry(n, struct btrfs_qgroup, rb_node);
+		stats->qgroupid = qgroup->qgroupid;
+		stats->info = qgroup->info;
+		stats->limit = qgroup->limit;
+
+		ret = 0;
+	}
+
+	__free_all_qgroups(&qgroup_lookup);
+	return ret;
+}
+
 static void print_all_qgroups(struct qgroup_lookup *qgroup_lookup, bool verbose)
 {
 

@@ -1293,7 +1335,7 @@ int btrfs_show_qgroups(int fd,
 	struct qgroup_lookup sort_tree;
 	int ret;
 
-	ret = __qgroups_search(fd, &qgroup_lookup);
+	ret = qgroups_search_all(fd, &qgroup_lookup);
 	if (ret)
 		return ret;
 	__filter_and_sort_qgroups(&qgroup_lookup, &sort_tree,

qgroup.h +7 -0

index 5e71349c..688f92b2 100644
@@ -87,6 +87,12 @@ struct btrfs_qgroup_info {
 	u64 exclusive_compressed;
 };
 
+struct btrfs_qgroup_stats {
+	u64 qgroupid;
+	struct btrfs_qgroup_info info;
+	struct btrfs_qgroup_limit limit;
+};
+
 int btrfs_qgroup_parse_sort_string(const char *opt_arg,
 				struct btrfs_qgroup_comparer_set **comps);
 int btrfs_show_qgroups(int fd, struct btrfs_qgroup_filter_set *,

@@ -105,4 +111,5 @@ int qgroup_inherit_add_group(struct btrfs_qgroup_inherit **inherit, char *arg);
 int qgroup_inherit_add_copy(struct btrfs_qgroup_inherit **inherit, char *arg,
 			    int type);
 
+int btrfs_qgroup_query(int fd, u64 qgroupid, struct btrfs_qgroup_stats *stats);
 #endif

Quoted 32 lines · On 2018年03月03日 02:47, [email protected] wrote:

qgroup.c +24 -0

index b1be3311..2d0a6947 100644
@@ -1267,6 +1249,66 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 	return ret;
 }
 
+static int qgroups_search_all(int fd, struct qgroup_lookup *qgroup_lookup)
+{
+	struct btrfs_ioctl_search_args args = {
+		.key = {
+			.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
+			.max_type = BTRFS_QGROUP_RELATION_KEY,
+			.min_type = BTRFS_QGROUP_STATUS_KEY,
+			.max_objectid = (u64)-1,
+			.max_offset = (u64)-1,
+			.max_transid = (u64)-1,
+			.nr_items = 4096,
+		},
+	};
+	int ret;
+
+	ret = __qgroups_search(fd, &args, qgroup_lookup);
+	if (ret == -ENOTTY)
+		error("can't list qgroups: quotas not enabled");
+	else if (ret < 0)
+		error("can't list qgroups: %s", strerror(-ret));
+	return ret;
+}
+
+int btrfs_qgroup_query(int fd, u64 qgroupid, struct btrfs_qgroup_stats *stats)

qgroup.c static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup) · line 1285

Quoted 10 lines

qgroup.c +10 -0

+{
+	struct btrfs_ioctl_search_args args = {
+		.key = {
+			.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
+			.min_type = BTRFS_QGROUP_INFO_KEY,
+			.max_type = BTRFS_QGROUP_LIMIT_KEY,
+			.max_objectid = 0,
+			.max_offset = qgroupid,
+			.max_transid = (u64)-1,
+			.nr_items = 4096, /* should be 2, i think */

2 is not correct in fact.

As QGROUP_INFO is smaller than QGROUP_LIMIT, to get a slice of all what we need, we need to include all other unrelated items.

One example will be:

	item 1 key (0 QGROUP_INFO 0/5) itemoff 16211 itemsize 40
	item 2 key (0 QGROUP_INFO 0/257) itemoff 16171 itemsize 40
	item 3 key (0 QGROUP_INFO 1/1) itemoff 16131 itemsize 40
	item 4 key (0 QGROUP_LIMIT 0/5) itemoff 16091 itemsize 40
	item 5 key (0 QGROUP_LIMIT 0/257) itemoff 16051 itemsize 40
	item 6 key (0 QGROUP_LIMIT 1/1) itemoff 16011 itemsize 40

To query qgroup info about 0/257, above setup will get the following slice:

	item 1 key (0 QGROUP_INFO 0/5) itemoff 16211 itemsize 40
	item 2 key (0 QGROUP_INFO 0/257) itemoff 16171 itemsize 40
	item 3 key (0 QGROUP_INFO 1/1) itemoff 16131 itemsize 40
	item 4 key (0 QGROUP_LIMIT 0/5) itemoff 16091 itemsize 40
	item 5 key (0 QGROUP_LIMIT 0/257) itemoff 16051 itemsize 40

So we still need that large @nr_items.

Despite this comment it looks good.

From: Jeff Mahoney <[email protected]>

The only mechanism we have in the progs for searching qgroups is to load all of them and filter the results. This works for qgroup show but to add quota information to 'btrfs subvoluem show' it's pretty wasteful.

This patch splits out setting up the search and performing the search so we can search for a single qgroupid more easily.

Signed-off-by Jeff Mahoney <[email protected]>

---
 qgroup.c | 98 +++++++++++++++++++++++++++++++++++++++++++++-------------------
 qgroup.h |  7 +++++
 2 files changed, 77 insertions(+), 28 deletions(-)

qgroup.c +51 -27

index b1be3311..2d0a6947 100644
@@ -1146,11 +1146,11 @@ static inline void print_status_flag_warning(u64 flags)
 		warning("qgroup data inconsistent, rescan recommended");
 }
 
-static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
+static int __qgroups_search(int fd, struct btrfs_ioctl_search_args *args,
+			    struct qgroup_lookup *qgroup_lookup)
 {
 	int ret;
-	struct btrfs_ioctl_search_args args;
-	struct btrfs_ioctl_search_key *sk = &args.key;
+	struct btrfs_ioctl_search_key *sk = &args->key;
 	struct btrfs_ioctl_search_header *sh;
 	unsigned long off = 0;
 	unsigned int i;

@@ -1161,30 +1161,12 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 	u64 qgroupid;
 	u64 qgroupid1;
 
-	memset(&args, 0, sizeof(args));
-
-	sk->tree_id = BTRFS_QUOTA_TREE_OBJECTID;
-	sk->max_type = BTRFS_QGROUP_RELATION_KEY;
-	sk->min_type = BTRFS_QGROUP_STATUS_KEY;
-	sk->max_objectid = (u64)-1;
-	sk->max_offset = (u64)-1;
-	sk->max_transid = (u64)-1;
-	sk->nr_items = 4096;
-
 	qgroup_lookup_init(qgroup_lookup);
 
 	while (1) {
-		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, args);
 		if (ret < 0) {
-			if (errno == ENOENT) {
-				error("can't list qgroups: quotas not enabled");
-				ret = -ENOTTY;
-			} else {
-				error("can't list qgroups: %s",
-				       strerror(errno));
-				ret = -errno;
-			}
-
+			ret = -errno;
 			break;
 		}
 

@@ -1198,14 +1180,14 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 		 * read the root_ref item it contains
 		 */
 		for (i = 0; i < sk->nr_items; i++) {
-			sh = (struct btrfs_ioctl_search_header *)(args.buf +
+			sh = (struct btrfs_ioctl_search_header *)(args->buf +
 								  off);
 			off += sizeof(*sh);
 
 			switch (btrfs_search_header_type(sh)) {
 			case BTRFS_QGROUP_STATUS_KEY:
 				si = (struct btrfs_qgroup_status_item *)
-				     (args.buf + off);
+				     (args->buf + off);
 				flags = btrfs_stack_qgroup_status_flags(si);
 
 				print_status_flag_warning(flags);

@@ -1213,7 +1195,7 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 			case BTRFS_QGROUP_INFO_KEY:
 				qgroupid = btrfs_search_header_offset(sh);
 				info = (struct btrfs_qgroup_info_item *)
-				       (args.buf + off);
+				       (args->buf + off);
 
 				ret = update_qgroup_info(fd, qgroup_lookup,
 							 qgroupid, info);

@@ -1221,7 +1203,7 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 			case BTRFS_QGROUP_LIMIT_KEY:
 				qgroupid = btrfs_search_header_offset(sh);
 				limit = (struct btrfs_qgroup_limit_item *)
-					(args.buf + off);
+					(args->buf + off);
 
 				ret = update_qgroup_limit(fd, qgroup_lookup,
 							  qgroupid, limit);

@@ -1267,6 +1249,66 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 	return ret;
 }
 
+static int qgroups_search_all(int fd, struct qgroup_lookup *qgroup_lookup)
+{
+	struct btrfs_ioctl_search_args args = {
+		.key = {
+			.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
+			.max_type = BTRFS_QGROUP_RELATION_KEY,
+			.min_type = BTRFS_QGROUP_STATUS_KEY,
+			.max_objectid = (u64)-1,
+			.max_offset = (u64)-1,
+			.max_transid = (u64)-1,
+			.nr_items = 4096,
+		},
+	};
+	int ret;
+
+	ret = __qgroups_search(fd, &args, qgroup_lookup);
+	if (ret == -ENOTTY)
+		error("can't list qgroups: quotas not enabled");
+	else if (ret < 0)
+		error("can't list qgroups: %s", strerror(-ret));
+	return ret;
+}
+
+int btrfs_qgroup_query(int fd, u64 qgroupid, struct btrfs_qgroup_stats *stats)
+{
+	struct btrfs_ioctl_search_args args = {
+		.key = {
+			.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
+			.min_type = BTRFS_QGROUP_INFO_KEY,
+			.max_type = BTRFS_QGROUP_LIMIT_KEY,
+			.max_objectid = 0,
+			.max_offset = qgroupid,
+			.max_transid = (u64)-1,
+			.nr_items = 4096, /* should be 2, i think */
+		},
+	};
+	struct qgroup_lookup qgroup_lookup;
+	struct btrfs_qgroup *qgroup;
+	struct rb_node *n;
+	int ret;
+
+	ret = __qgroups_search(fd, &args, &qgroup_lookup);

qgroup.c +9 -1

+
+		ret = 0;
+	}
+
+	__free_all_qgroups(&qgroup_lookup);
+	return ret;
+}
+
 static void print_all_qgroups(struct qgroup_lookup *qgroup_lookup, bool verbose)
 {
 

@@ -1293,7 +1335,7 @@ int btrfs_show_qgroups(int fd,
 	struct qgroup_lookup sort_tree;
 	int ret;
 
-	ret = __qgroups_search(fd, &qgroup_lookup);
+	ret = qgroups_search_all(fd, &qgroup_lookup);
 	if (ret)
 		return ret;
 	__filter_and_sort_qgroups(&qgroup_lookup, &sort_tree,

qgroup.h +7 -0

index 5e71349c..688f92b2 100644
@@ -87,6 +87,12 @@ struct btrfs_qgroup_info {
 	u64 exclusive_compressed;
 };
 
+struct btrfs_qgroup_stats {
+	u64 qgroupid;
+	struct btrfs_qgroup_info info;
+	struct btrfs_qgroup_limit limit;
+};
+
 int btrfs_qgroup_parse_sort_string(const char *opt_arg,
 				struct btrfs_qgroup_comparer_set **comps);
 int btrfs_show_qgroups(int fd, struct btrfs_qgroup_filter_set *,

@@ -105,4 +111,5 @@ int qgroup_inherit_add_group(struct btrfs_qgroup_inherit **inherit, char *arg);
 int qgroup_inherit_add_copy(struct btrfs_qgroup_inherit **inherit, char *arg,
 			    int type);
 
+int btrfs_qgroup_query(int fd, u64 qgroupid, struct btrfs_qgroup_stats *stats);
 #endif

From: Jeff Mahoney <[email protected]>

The only mechanism we have in the progs for searching qgroups is to load all of them and filter the results. This works for qgroup show but to add quota information to 'btrfs subvoluem show' it's pretty wasteful.

This patch splits out setting up the search and performing the search so we can search for a single qgroupid more easily.

Signed-off-by Jeff Mahoney <[email protected]>

---
 qgroup.c | 98 +++++++++++++++++++++++++++++++++++++++++++++-------------------
 qgroup.h |  7 +++++
 2 files changed, 77 insertions(+), 28 deletions(-)

qgroup.c +4 -14

index b1be3311..2d0a6947 100644
@@ -1146,11 +1146,11 @@ static inline void print_status_flag_warning(u64 flags)
 		warning("qgroup data inconsistent, rescan recommended");
 }
 
-static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
+static int __qgroups_search(int fd, struct btrfs_ioctl_search_args *args,
+			    struct qgroup_lookup *qgroup_lookup)
 {
 	int ret;
-	struct btrfs_ioctl_search_args args;
-	struct btrfs_ioctl_search_key *sk = &args.key;
+	struct btrfs_ioctl_search_key *sk = &args->key;
 	struct btrfs_ioctl_search_header *sh;
 	unsigned long off = 0;
 	unsigned int i;

@@ -1161,30 +1161,12 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 	u64 qgroupid;
 	u64 qgroupid1;
 
-	memset(&args, 0, sizeof(args));
-
-	sk->tree_id = BTRFS_QUOTA_TREE_OBJECTID;
-	sk->max_type = BTRFS_QGROUP_RELATION_KEY;
-	sk->min_type = BTRFS_QGROUP_STATUS_KEY;
-	sk->max_objectid = (u64)-1;
-	sk->max_offset = (u64)-1;
-	sk->max_transid = (u64)-1;
-	sk->nr_items = 4096;
-
 	qgroup_lookup_init(qgroup_lookup);
 
 	while (1) {
-		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, args);
 		if (ret < 0) {

qgroup.c +65 -5

 			break;
 		}
 

@@ -1198,14 +1180,14 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 		 * read the root_ref item it contains
 		 */
 		for (i = 0; i < sk->nr_items; i++) {
-			sh = (struct btrfs_ioctl_search_header *)(args.buf +
+			sh = (struct btrfs_ioctl_search_header *)(args->buf +
 								  off);
 			off += sizeof(*sh);
 
 			switch (btrfs_search_header_type(sh)) {
 			case BTRFS_QGROUP_STATUS_KEY:
 				si = (struct btrfs_qgroup_status_item *)
-				     (args.buf + off);
+				     (args->buf + off);
 				flags = btrfs_stack_qgroup_status_flags(si);
 
 				print_status_flag_warning(flags);

@@ -1213,7 +1195,7 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 			case BTRFS_QGROUP_INFO_KEY:
 				qgroupid = btrfs_search_header_offset(sh);
 				info = (struct btrfs_qgroup_info_item *)
-				       (args.buf + off);
+				       (args->buf + off);
 
 				ret = update_qgroup_info(fd, qgroup_lookup,
 							 qgroupid, info);

@@ -1221,7 +1203,7 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 			case BTRFS_QGROUP_LIMIT_KEY:
 				qgroupid = btrfs_search_header_offset(sh);
 				limit = (struct btrfs_qgroup_limit_item *)
-					(args.buf + off);
+					(args->buf + off);
 
 				ret = update_qgroup_limit(fd, qgroup_lookup,
 							  qgroupid, limit);

@@ -1267,6 +1249,66 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 	return ret;
 }
 
+static int qgroups_search_all(int fd, struct qgroup_lookup *qgroup_lookup)
+{
+	struct btrfs_ioctl_search_args args = {
+		.key = {
+			.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
+			.max_type = BTRFS_QGROUP_RELATION_KEY,
+			.min_type = BTRFS_QGROUP_STATUS_KEY,
+			.max_objectid = (u64)-1,
+			.max_offset = (u64)-1,
+			.max_transid = (u64)-1,
+			.nr_items = 4096,
+		},
+	};
+	int ret;
+
+	ret = __qgroups_search(fd, &args, qgroup_lookup);
+	if (ret == -ENOTTY)
+		error("can't list qgroups: quotas not enabled");
+	else if (ret < 0)
+		error("can't list qgroups: %s", strerror(-ret));
+	return ret;
+}
+
+int btrfs_qgroup_query(int fd, u64 qgroupid, struct btrfs_qgroup_stats *stats)
+{
+	struct btrfs_ioctl_search_args args = {
+		.key = {
+			.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
+			.min_type = BTRFS_QGROUP_INFO_KEY,
+			.max_type = BTRFS_QGROUP_LIMIT_KEY,
+			.max_objectid = 0,
+			.max_offset = qgroupid,
+			.max_transid = (u64)-1,
+			.nr_items = 4096, /* should be 2, i think */
+		},
+	};
+	struct qgroup_lookup qgroup_lookup;
+	struct btrfs_qgroup *qgroup;
+	struct rb_node *n;
+	int ret;
+
+	ret = __qgroups_search(fd, &args, &qgroup_lookup);
+	if (ret < 0)
+		return ret;
+
+	ret = -ENODATA;
+	n = rb_first(&qgroup_lookup.root);
+	if (n) {
+		qgroup = rb_entry(n, struct btrfs_qgroup, rb_node);
+		stats->qgroupid = qgroup->qgroupid;
+		stats->info = qgroup->info;
+		stats->limit = qgroup->limit;
+
+		ret = 0;
+	}
+
+	__free_all_qgroups(&qgroup_lookup);
+	return ret;
+}
+
 static void print_all_qgroups(struct qgroup_lookup *qgroup_lookup, bool verbose)
 {
 

@@ -1293,7 +1335,7 @@ int btrfs_show_qgroups(int fd,
 	struct qgroup_lookup sort_tree;
 	int ret;
 
-	ret = __qgroups_search(fd, &qgroup_lookup);
+	ret = qgroups_search_all(fd, &qgroup_lookup);
 	if (ret)
 		return ret;
 	__filter_and_sort_qgroups(&qgroup_lookup, &sort_tree,

qgroup.h +7 -0

index 5e71349c..688f92b2 100644
@@ -87,6 +87,12 @@ struct btrfs_qgroup_info {
 	u64 exclusive_compressed;
 };
 
+struct btrfs_qgroup_stats {
+	u64 qgroupid;
+	struct btrfs_qgroup_info info;
+	struct btrfs_qgroup_limit limit;
+};
+
 int btrfs_qgroup_parse_sort_string(const char *opt_arg,
 				struct btrfs_qgroup_comparer_set **comps);
 int btrfs_show_qgroups(int fd, struct btrfs_qgroup_filter_set *,

@@ -105,4 +111,5 @@ int qgroup_inherit_add_group(struct btrfs_qgroup_inherit **inherit, char *arg);
 int qgroup_inherit_add_copy(struct btrfs_qgroup_inherit **inherit, char *arg,
 			    int type);
 
+int btrfs_qgroup_query(int fd, u64 qgroupid, struct btrfs_qgroup_stats *stats);
 #endif

Quoted 60 lines · On 2018/03/03 3:47, [email protected] wrote:

From: Jeff Mahoney <[email protected]>

The only mechanism we have in the progs for searching qgroups is to load all of them and filter the results. This works for qgroup show but to add quota information to 'btrfs subvoluem show' it's pretty wasteful.

This patch splits out setting up the search and performing the search so we can search for a single qgroupid more easily.

Signed-off-by Jeff Mahoney <[email protected]>

---
 qgroup.c | 98 +++++++++++++++++++++++++++++++++++++++++++++-------------------
 qgroup.h |  7 +++++
 2 files changed, 77 insertions(+), 28 deletions(-)

qgroup.c +4 -20

index b1be3311..2d0a6947 100644
@@ -1146,11 +1146,11 @@ static inline void print_status_flag_warning(u64 flags)
 		warning("qgroup data inconsistent, rescan recommended");
 }
 
-static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
+static int __qgroups_search(int fd, struct btrfs_ioctl_search_args *args,
+			    struct qgroup_lookup *qgroup_lookup)
 {
 	int ret;
-	struct btrfs_ioctl_search_args args;
-	struct btrfs_ioctl_search_key *sk = &args.key;
+	struct btrfs_ioctl_search_key *sk = &args->key;
 	struct btrfs_ioctl_search_header *sh;
 	unsigned long off = 0;
 	unsigned int i;

@@ -1161,30 +1161,12 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 	u64 qgroupid;
 	u64 qgroupid1;
 
-	memset(&args, 0, sizeof(args));
-
-	sk->tree_id = BTRFS_QUOTA_TREE_OBJECTID;
-	sk->max_type = BTRFS_QGROUP_RELATION_KEY;
-	sk->min_type = BTRFS_QGROUP_STATUS_KEY;
-	sk->max_objectid = (u64)-1;
-	sk->max_offset = (u64)-1;
-	sk->max_transid = (u64)-1;
-	sk->nr_items = 4096;
-
 	qgroup_lookup_init(qgroup_lookup);
 
 	while (1) {
-		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, args);
 		if (ret < 0) {
-			if (errno == ENOENT) {
-				error("can't list qgroups: quotas not enabled");
-				ret = -ENOTTY;
-			} else {
-				error("can't list qgroups: %s",
-				       strerror(errno));

qgroup.c static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup) · line 1169

Quoted 4 lines

qgroup.c +1 -3

-				ret = -errno;
-			}
-
+			ret = -errno;

Originally, -ENOTTY would be returned when qgroup is disabled but this changes to return -ENOENT. so, it seems that error check in 7th patch would not work correctly when qgroup is disabled.

From: Jeff Mahoney <[email protected]>

This patch reports on the first-level qgroup, if any, associated with a particular subvolume. It displays the usage and limit, subject to the usual unit parameters.

Signed-off-by Jeff Mahoney <[email protected]>

---
 cmds-subvolume.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

cmds-subvolume.c +8 -0

index 8a473f7a..29d0e0e5 100644
@@ -972,6 +972,7 @@ static const char * const cmd_subvol_show_usage[] = {
 	"Show more information about the subvolume",
 	"-r|--rootid   rootid of the subvolume",
 	"-u|--uuid     uuid of the subvolume",
+	HELPINFO_UNITS_SHORT_LONG,
 	"",
 	"If no option is specified, <subvol-path> will be shown, otherwise",
 	"the rootid or uuid are resolved relative to the <mnt> path.",

@@ -993,6 +994,13 @@ static int cmd_subvol_show(int argc, char **argv)
 	int by_uuid = 0;
 	u64 rootid_arg;
 	u8 uuid_arg[BTRFS_UUID_SIZE];
+	struct btrfs_qgroup_stats stats;
+	unsigned int unit_mode;
+	const char *referenced_size;
+	const char *referenced_limit_size = "-";
+	unsigned field_width = 0;
+
+	unit_mode = get_unit_mode_from_arg(&argc, argv, 1);
 
 	while (1) {
 		int c;

cmds-subvolume.c +34 -0

+		else if (ret != -ENOTTY)
+			fprintf(stderr,
+				"\nERROR: BTRFS_IOC_QUOTA_QUERY failed: %s\n",
+				strerror(errno));
+		goto out;
+	}
+
+	printf("\tQuota Usage:\t\t");
+	fflush(stdout);
+
+	referenced_size = pretty_size_mode(stats.info.referenced, unit_mode);
+	if (stats.limit.max_referenced)
+	       referenced_limit_size = pretty_size_mode(
+						stats.limit.max_referenced,
+						unit_mode);
+	field_width = max(strlen(referenced_size),
+			  strlen(referenced_limit_size));
+
+	printf("%-*s referenced, %s exclusive\n ", field_width,
+	       referenced_size,
+	       pretty_size_mode(stats.info.exclusive, unit_mode));
+
+	printf("\tQuota Limits:\t\t");
+	if (stats.limit.max_referenced || stats.limit.max_exclusive) {
+		const char *excl = "-";
+
+		if (stats.limit.max_exclusive)
+		       excl = pretty_size_mode(stats.limit.max_exclusive,
+					       unit_mode);
+		printf("%-*s referenced, %s exclusive\n", field_width,
+		       referenced_limit_size, excl);
+	} else
+		printf("None\n");
+
 out:
 	/* clean up */
 	free(get_ri.path);

Quoted 38 lines · On 2018年03月03日 02:47, [email protected] wrote:

From: Jeff Mahoney <[email protected]>

This patch reports on the first-level qgroup, if any, associated with a particular subvolume. It displays the usage and limit, subject to the usual unit parameters.

Signed-off-by Jeff Mahoney <[email protected]>

---
 cmds-subvolume.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

cmds-subvolume.c +8 -0

index 8a473f7a..29d0e0e5 100644
@@ -972,6 +972,7 @@ static const char * const cmd_subvol_show_usage[] = {
 	"Show more information about the subvolume",
 	"-r|--rootid   rootid of the subvolume",
 	"-u|--uuid     uuid of the subvolume",
+	HELPINFO_UNITS_SHORT_LONG,
 	"",
 	"If no option is specified, <subvol-path> will be shown, otherwise",
 	"the rootid or uuid are resolved relative to the <mnt> path.",

@@ -993,6 +994,13 @@ static int cmd_subvol_show(int argc, char **argv)
 	int by_uuid = 0;
 	u64 rootid_arg;
 	u8 uuid_arg[BTRFS_UUID_SIZE];
+	struct btrfs_qgroup_stats stats;
+	unsigned int unit_mode;
+	const char *referenced_size;
+	const char *referenced_limit_size = "-";
+	unsigned field_width = 0;
+
+	unit_mode = get_unit_mode_from_arg(&argc, argv, 1);
 
 	while (1) {
 		int c;

cmds-subvolume.c static int cmd_subvol_show(int argc, char **argv) · line 1126

Quoted 7 lines

cmds-subvolume.c +4 -0

@@ -1112,6 +1120,44 @@ static int cmd_subvol_show(int argc, char **argv)
 	btrfs_list_subvols_print(fd, filter_set, NULL, BTRFS_LIST_LAYOUT_RAW,
 			1, raw_prefix);
 
+	ret = btrfs_qgroup_query(fd, get_ri.root_id, &stats);
+	if (ret < 0) {
+		if (ret == -ENODATA)
+			printf("Quotas must be enabled for per-subvolume usage\n");

This seems a little confusing.
If quota is disabled, we get ENOTTY not ENODATA.

For ENODATA we know quota is enabled but just no info for this qgroup.

Thanks,
Qu

Quoted 38 lines

cmds-subvolume.c +34 -0

+		else if (ret != -ENOTTY)
+			fprintf(stderr,
+				"\nERROR: BTRFS_IOC_QUOTA_QUERY failed: %s\n",
+				strerror(errno));
+		goto out;
+	}
+
+	printf("\tQuota Usage:\t\t");
+	fflush(stdout);
+
+	referenced_size = pretty_size_mode(stats.info.referenced, unit_mode);
+	if (stats.limit.max_referenced)
+	       referenced_limit_size = pretty_size_mode(
+						stats.limit.max_referenced,
+						unit_mode);
+	field_width = max(strlen(referenced_size),
+			  strlen(referenced_limit_size));
+
+	printf("%-*s referenced, %s exclusive\n ", field_width,
+	       referenced_size,
+	       pretty_size_mode(stats.info.exclusive, unit_mode));
+
+	printf("\tQuota Limits:\t\t");
+	if (stats.limit.max_referenced || stats.limit.max_exclusive) {
+		const char *excl = "-";
+
+		if (stats.limit.max_exclusive)
+		       excl = pretty_size_mode(stats.limit.max_exclusive,
+					       unit_mode);
+		printf("%-*s referenced, %s exclusive\n", field_width,
+		       referenced_limit_size, excl);
+	} else
+		printf("None\n");
+
 out:
 	/* clean up */
 	free(get_ri.path);

From: Jeff Mahoney <[email protected]>

One of the common requests I receive is for 'df' like facilities for subvolume usage. Really, the request is for monitoring tools to be able to understand when subvolumes may be approaching quota in the same manner traditional file systems approach ENOSPC.

This patch allows us to export the qgroups data in a machine-readable format so that monitoring tools can parse it easily.

There are two modes since JSON can technically handle 64-bit numbers but JavaScript proper cannot. show -j enables JSON mode using 64-bit integers directly. --json-compat presents 64-bit numbers as an array of two 32-bit numbers (high followed by low).

Signed-off-by Jeff Mahoney <[email protected]>

---
 Documentation/btrfs-qgroup.asciidoc |   4 +
 Makefile.inc.in                     |   4 +-
 cmds-qgroup.c                       |  36 +++++-
 configure.ac                        |   6 +
 qgroup.c                            | 211 ++++++++++++++++++++++++++++++++++++
 qgroup.h                            |   3 +
 6 files changed, 258 insertions(+), 6 deletions(-)

Documentation/btrfs-qgroup.asciidoc +4 -0

index 360b3269..22a9c2a7 100644
@@ -105,6 +105,10 @@ list all qgroups which impact the given path(include ancestral qgroups)
 list all qgroups which impact the given path(exclude ancestral qgroups)
 -v::::
 Be more verbose.  Print pathnames of member qgroups when nested.
+-j::::
+If enabled, export qgroup usage information in JSON format.  This implies --raw.
+--json-compat::::
+By default, JSON output contains full 64-bit integers, which may be incompatible with some JSON parsers.  This option exports those values as an array of 32-bit numbers in [high, low] format.
 --raw::::
 raw numbers in bytes, without the 'B' suffix.
 --human-readable::::

Makefile.inc.in +2 -2

index 56271903..68bddbed 100644
@@ -18,9 +18,9 @@ BTRFSRESTORE_ZSTD = @BTRFSRESTORE_ZSTD@
 SUBST_CFLAGS = @CFLAGS@
 SUBST_LDFLAGS = @LDFLAGS@
 
-LIBS_BASE = @UUID_LIBS@ @BLKID_LIBS@ -L. -pthread
+LIBS_BASE = @UUID_LIBS@ @BLKID_LIBS@ @JSON_LIBS@ -L. -pthread
 LIBS_COMP = @ZLIB_LIBS@ @LZO2_LIBS@ @ZSTD_LIBS@
-STATIC_LIBS_BASE = @UUID_LIBS_STATIC@ @BLKID_LIBS_STATIC@ -L. -pthread
+STATIC_LIBS_BASE = @UUID_LIBS_STATIC@ @BLKID_LIBS_STATIC@ @JSON_LIBS_STATIC@ -L. -pthread
 STATIC_LIBS_COMP = @ZLIB_LIBS_STATIC@ @LZO2_LIBS_STATIC@ @ZSTD_LIBS_STATIC@
 
 prefix ?= @prefix@

cmds-qgroup.c +32 -4

index 94cd0fd3..eee15ef1 100644
@@ -282,6 +282,10 @@ static const char * const cmd_qgroup_show_usage[] = {
 	"               (excluding ancestral qgroups)",
 	"-P             print first-level qgroups using pathname",
 	"-v             verbose, prints all nested subvolumes",
+#ifdef HAVE_JSON
+	"-j             export in JSON format",
+	"--json-compat  export in JSON compatibility mode",
+#endif
 	HELPINFO_UNITS_LONG,
 	"--sort=qgroupid,rfer,excl,max_rfer,max_excl,pathname",
 	"               list qgroups sorted by specified items",

@@ -302,6 +306,8 @@ static int cmd_qgroup_show(int argc, char **argv)
 	unsigned unit_mode;
 	int sync = 0;
 	bool verbose = false;
+	bool export_json = false;
+	bool compat_json = false;
 
 	struct btrfs_qgroup_comparer_set *comparer_set;
 	struct btrfs_qgroup_filter_set *filter_set;

@@ -314,16 +320,26 @@ static int cmd_qgroup_show(int argc, char **argv)
 		int c;
 		enum {
 			GETOPT_VAL_SORT = 256,
-			GETOPT_VAL_SYNC
+			GETOPT_VAL_SYNC,
+			GETOPT_VAL_JSCOMPAT,
 		};
 		static const struct option long_options[] = {
 			{"sort", required_argument, NULL, GETOPT_VAL_SORT},
 			{"sync", no_argument, NULL, GETOPT_VAL_SYNC},
 			{"verbose", no_argument, NULL, 'v'},
+#ifdef HAVE_JSON
+			{"json-compat", no_argument, NULL, GETOPT_VAL_JSCOMPAT},
+#endif
 			{ NULL, 0, NULL, 0 }
 		};
-
-		c = getopt_long(argc, argv, "pPcreFfv", long_options, NULL);
+		const char getopt_chars[] = {
+			'p', 'P', 'c', 'r', 'e', 'F', 'f', 'v',
+#ifdef HAVE_JSON
+			'j',
+#endif
+			'\0' };
+
+		c = getopt_long(argc, argv, getopt_chars, long_options, NULL);
 		if (c < 0)
 			break;
 		switch (c) {

@@ -353,6 +369,14 @@ static int cmd_qgroup_show(int argc, char **argv)
 		case 'f':
 			filter_flag |= 0x2;
 			break;
+#ifdef HAVE_JSON
+		case GETOPT_VAL_JSCOMPAT:
+			compat_json = true;
+		case 'j':
+			unit_mode = UNITS_RAW;
+			export_json = true;
+			break;
+#endif
 		case GETOPT_VAL_SORT:
 			ret = btrfs_qgroup_parse_sort_string(optarg,
 							     &comparer_set);

@@ -405,7 +429,11 @@ static int cmd_qgroup_show(int argc, char **argv)
 					BTRFS_QGROUP_FILTER_PARENT,
 					qgroupid);
 	}
-	ret = btrfs_show_qgroups(fd, filter_set, comparer_set, verbose);
+	if (export_json)
+		ret = btrfs_export_qgroups_json(fd, filter_set, comparer_set,
+						compat_json);
+	else
+		ret = btrfs_show_qgroups(fd, filter_set, comparer_set, verbose);
 	close_file_or_dir(fd, dirstream);
 	free(filter_set);
 	free(comparer_set);

configure.ac +0 -0

index 56d17c3a..6aec672a 100644

configure.ac +5 -0

+	AC_DEFINE(HAVE_JSON, [1], [Have JSON]),
+	PKG_STATIC(JSON_LIBS_STATIC, [json-c], [
+		AC_DEFINE(HAVE_JSON_STATIC, [1], [Have JSON static])], [true])
+	], [true])
+
 AC_ARG_ENABLE([zstd],
 	AS_HELP_STRING([--disable-zstd], [build without zstd support]),
 	[], [enable_zstd=yes]

qgroup.c +4 -0

index 2d0a6947..f632a45c 100644
@@ -16,12 +16,16 @@
  * Boston, MA 021110-1307, USA.
  */
 
+#include "version.h"
 #include "qgroup.h"
 #include <sys/ioctl.h>
 #include "ctree.h"
 #include "ioctl.h"
 #include "utils.h"
 #include <errno.h>
+#ifdef HAVE_JSON
+#include <json-c/json.h>
+#endif
 
 #define BTRFS_QGROUP_NFILTERS_INCREASE (2 * BTRFS_QGROUP_FILTER_MAX)
 #define BTRFS_QGROUP_NCOMPS_INCREASE (2 * BTRFS_QGROUP_COMP_MAX)

@@ -1346,6 +1350,213 @@ int btrfs_show_qgroups(int fd,
 	return ret;
 }

qgroup.c +25 -0

+}
+
+static json_object *export_one_u64(u64 value, bool compat)
+{
+	json_object *array, *tmp;
+
+	if (!compat)
+		return json_object_new_int64(value);
+
+	array = json_object_new_array();
+	if (!array)
+		return NULL;
+
+	tmp = json_object_new_int(value >> 32);
+	if (!tmp)
+		goto failure;
+	json_object_array_add(array, tmp);
+
+	tmp = json_object_new_int(value & 0xffffffff);
+	if (!tmp)
+		goto failure;
+	json_object_array_add(array, tmp);
+
+	return array;
+failure:

qgroup.c +162 -0

+
+	format_qgroupid(buf, sizeof(buf), qgroup->qgroupid);
+	tmp = json_object_new_string(buf);
+	if (!tmp)
+		return false;
+	json_object_object_add(obj, "qgroupid", tmp);
+
+	tmp = export_one_u64(qgroup->qgroupid, compat);
+	if (!tmp)
+		goto failure;
+	json_object_object_add(obj, "qgroupid_raw", tmp);> +
+	tmp = export_one_u64(qgroup->info.generation, compat);
+	if (!tmp)
+		goto failure;
+	json_object_object_add(obj, "generation", tmp);
+
+	tmp = export_one_u64(qgroup->info.referenced, compat);
+	if (!tmp)
+		goto failure;
+	json_object_object_add(obj, "referenced_bytes", tmp);
+
+	tmp = export_one_u64(qgroup->info.exclusive, compat);
+	if (!tmp)
+		goto failure;
+	json_object_object_add(obj, "exclusive_bytes", tmp);
+
+	tmp = export_one_u64(qgroup->limit.max_referenced, compat);
+	if (!tmp)
+		goto failure;
+	json_object_object_add(obj, "referenced_limit_bytes", tmp);
+
+	tmp = export_one_u64(qgroup->limit.max_exclusive, compat);
+	if (!tmp)
+		goto failure;
+	json_object_object_add(obj, "exclusive_limit_bytes", tmp);
+
+	if (btrfs_qgroup_level(qgroup->qgroupid) == 0) {
+		tmp = json_object_new_string(qgroup->pathname);
+		if (!tmp)
+			goto failure;
+		json_object_object_add(obj, "pathname", tmp);
+	} else {
+		json_object *array = json_object_new_array();
+		struct btrfs_qgroup_list *list = NULL;
+		if (!array)
+			goto failure;
+		json_object_object_add(obj, "members", array);
+
+		list_for_each_entry(list, &qgroup->qgroups, next_qgroup) {
+			struct btrfs_qgroup *member = list->qgroup;
+			char buf2[42];
+
+			format_qgroupid(buf2, sizeof(buf2), member->qgroupid);
+			tmp = json_object_new_string(buf2);
+			if (!tmp)
+				goto failure;
+
+			json_object_array_add(array, tmp);
+		}
+	}
+
+	json_object_object_add(container, buf, obj);
+	return true;
+failure:
+	json_object_put(obj);
+	return false;
+}
+
+#define BTRFS_JSON_WARNING \
+"This data contains 64-bit values that are incompatible with Javascript. Export in compatibility mode using --json-compat."
+
+static void export_all_qgroups(const struct qgroup_lookup *qgroup_lookup,
+			       bool compat)
+{
+
+	struct rb_node *n;
+	const char *json;
+	json_object *container, *dict, *obj;
+	struct btrfs_qgroup *entry;
+
+	container = json_object_new_object();
+	if (!container)
+		goto failure_msg;
+
+	obj = json_object_new_string(BTRFS_BUILD_VERSION);
+	if (!obj)
+		goto failure;
+	json_object_object_add(container, "exporter", obj);
+
+	if (!compat) {
+		obj = json_object_new_string(BTRFS_JSON_WARNING);
+		if (!obj)
+			goto failure;
+		json_object_object_add(container, "compatibility-warning", obj);
+
+		obj = json_object_new_string("64-bit");
+		if (!obj)
+			goto failure;
+		json_object_object_add(container, "u64-format", obj);
+	} else {
+		obj = json_object_new_string("array");
+		if (!obj)
+			goto failure;
+		json_object_object_add(container, "u64-format", obj);
+	}
+
+	dict = json_object_new_object();
+	if (!dict)
+		goto failure;
+	json_object_object_add(container, "qgroup_data", dict);
+
+	n = rb_first(&qgroup_lookup->root);
+	while (n) {
+		entry = rb_entry(n, struct btrfs_qgroup, sort_node);
+		if (!export_one_qgroup(dict, entry, compat))
+			goto failure;
+		n = rb_next(n);
+	}
+
+	json = json_object_to_json_string(container);
+	if (!json)
+		goto failure;
+
+	puts(json);
+
+	/* clean up container */
+	json_object_put(container);
+	return;
+
+failure:
+	json_object_put(container);
+failure_msg:
+	error("Failed to create JSON object.");
+}
+#endif
+
+int btrfs_export_qgroups_json(int fd,
+			      struct btrfs_qgroup_filter_set *filter_set,
+			      struct btrfs_qgroup_comparer_set *comp_set,
+			      bool compat)
+{
+
+#ifdef HAVE_JSON
+	struct qgroup_lookup qgroup_lookup;
+	struct qgroup_lookup sort_tree;
+	int ret = 0;
+
+	ret = qgroups_search_all(fd, &qgroup_lookup);
+	if (ret)
+		return ret;
+	__filter_and_sort_qgroups(&qgroup_lookup, &sort_tree,
+				  filter_set, comp_set);
+	export_all_qgroups(&sort_tree, compat);
+
+	__free_all_qgroups(&qgroup_lookup);
+
+	return ret;
+#else
+	return 0;
+#endif
+}
+
 int btrfs_qgroup_parse_sort_string(const char *opt_arg,
 				   struct btrfs_qgroup_comparer_set **comps)
 {

qgroup.h +3 -0

index 688f92b2..2883727b 100644
@@ -97,6 +97,9 @@ int btrfs_qgroup_parse_sort_string(const char *opt_arg,
 				struct btrfs_qgroup_comparer_set **comps);
 int btrfs_show_qgroups(int fd, struct btrfs_qgroup_filter_set *,
 		       struct btrfs_qgroup_comparer_set *, bool verbose);
+int btrfs_export_qgroups_json(int fd, struct btrfs_qgroup_filter_set *,
+			      struct btrfs_qgroup_comparer_set *,
+			      bool compat);
 void btrfs_qgroup_setup_print_column(enum btrfs_qgroup_column_enum column);
 void btrfs_qgroup_setup_units(unsigned unit_mode);
 struct btrfs_qgroup_filter_set *btrfs_qgroup_alloc_filter_set(void);