From: Masatake YAMATO <yamato@redhat.com>
Date: Fri, 9 Sep 2022 17:03:45 +0000 (+0900)
Subject: lsfd: show pid, comm, and nspid of pidfd in PIDFD.{PID,COMM,NSPID} columns
X-Git-Tag: v2.39-rc1~527^2~2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=553a68178e6d2048fe7807a01a1876e3385ab261;p=thirdparty%2Futil-linux.git

lsfd: show pid, comm, and nspid of pidfd in PIDFD.{PID,COMM,NSPID} columns

The values shown in the new columns are already shown in NAME column.
Showing these values together in the NAME column helps users
understand the pidfds opened quickly. However, the showing them
together is not suitable for machine processing. The newly introduced
columns are for machine processing.

Below an example output:

    $ ./lsfd -o COMMAND,TYPE,PIDFD.COMM,PIDFD.PID -Q '(TYPE == "pidfd")'
    COMMAND          TYPE PIDFD.COMM  PIDFD.PID
    dbus-broker-lau pidfd dbus-broker      4661
    dbus-broker-lau pidfd dbus-broker      4924

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---

diff --git a/misc-utils/lsfd-unkn.c b/misc-utils/lsfd-unkn.c
index 470ca58ac9..e1fd259410 100644
--- a/misc-utils/lsfd-unkn.c
+++ b/misc-utils/lsfd-unkn.c
@@ -34,6 +34,13 @@ struct unkn {
 struct anon_ops {
 	const char *class;
 	char * (*get_name)(struct unkn *);
+	/* Return true is handled the column. */
+	bool (*fill_column)(struct proc *,
+			    struct unkn *,
+			    struct libscols_line *,
+			    int,
+			    size_t,
+			    char **str);
 	void (*init)(struct unkn *);
 	void (*free)(struct unkn *);
 	int (*handle_fdinfo)(struct unkn *, const char *, const char *);
@@ -61,7 +68,7 @@ static char * anon_get_class(struct unkn *unkn)
 	return strdup(name);
 }
 
-static bool unkn_fill_column(struct proc *proc __attribute__((__unused__)),
+static bool unkn_fill_column(struct proc *proc,
 			     struct file *file,
 			     struct libscols_line *ln,
 			     int column_id,
@@ -95,6 +102,11 @@ static bool unkn_fill_column(struct proc *proc __attribute__((__unused__)),
 		}
 		return false;
 	default:
+		if (unkn->anon_ops && unkn->anon_ops->fill_column) {
+			if (unkn->anon_ops->fill_column(proc, unkn, ln,
+							column_id, column_index, &str))
+				break;
+		}
 		return false;
 	}
 
@@ -204,9 +216,45 @@ static int anon_pidfd_handle_fdinfo(struct unkn *unkn, const char *key, const ch
 	return 0;
 }
 
+static bool anon_pidfd_fill_column(struct proc *proc  __attribute__((__unused__)),
+				   struct unkn *unkn,
+				   struct libscols_line *ln __attribute__((__unused__)),
+				   int column_id,
+				   size_t column_index __attribute__((__unused__)),
+				   char **str)
+{
+	struct anon_pidfd_data *data = (struct anon_pidfd_data *)unkn->anon_data;
+
+	switch(column_id) {
+	case COL_PIDFD_COMM: {
+		struct proc *pidfd_proc = get_proc(data->pid);
+		char *pidfd_comm = NULL;
+		if (pidfd_proc)
+			pidfd_comm = pidfd_proc->command;
+		if (pidfd_comm) {
+			*str = strdup(pidfd_comm);
+			return true;
+		}
+		break;
+	}
+	case COL_PIDFD_NSPID:
+		if (data->nspid) {
+			*str = strdup(data->nspid);
+			return true;
+		}
+		break;
+	case COL_PIDFD_PID:
+		xasprintf(str, "%d", (int)data->pid);
+		return true;
+	}
+
+	return false;
+}
+
 static struct anon_ops anon_pidfd_ops = {
 	.class = "pidfd",
 	.get_name = anon_pidfd_get_name,
+	.fill_column = anon_pidfd_fill_column,
 	.init = anon_pidfd_init,
 	.free = anon_pidfd_free,
 	.handle_fdinfo = anon_pidfd_handle_fdinfo,
@@ -218,6 +266,7 @@ static struct anon_ops anon_pidfd_ops = {
 static struct anon_ops anon_generic_ops = {
 	.class = NULL,
 	.get_name = NULL,
+	.fill_column = NULL,
 	.init = NULL,
 	.free = NULL,
 	.handle_fdinfo = NULL,
diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index f3b008d7a2..9981b6a363 100644
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -171,6 +171,12 @@ static struct colinfo infos[] = {
 		N_("PID of the process opening the file") },
 	[COL_PARTITION]={ "PARTITION",0, SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
 		N_("block device name resolved by /proc/partition") },
+	[COL_PIDFD_COMM]={"PIDFD.COMM",0.2,SCOLS_FL_TRUNC,SCOLS_JSON_STRING,
+		N_("command of the process targeted by the pidfd") },
+	[COL_PIDFD_NSPID]={"PIDFD.NSPID",0.2,SCOLS_FL_TRUNC,SCOLS_JSON_STRING,
+		N_("NSpid field in fdinfo of the pidfd") },
+	[COL_PIDFD_PID]={ "PIDFD.PID",5, SCOLS_FL_RIGHT, SCOLS_JSON_NUMBER,
+		N_("PID of the process targeted by the pidfd") },
 	[COL_POS]     = { "POS",      5, SCOLS_FL_RIGHT, SCOLS_JSON_NUMBER,
 		N_("file position") },
 	[COL_PROTONAME]={ "PROTONAME",0, SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
diff --git a/misc-utils/lsfd.h b/misc-utils/lsfd.h
index 794e2cc2a6..41f574ff4a 100644
--- a/misc-utils/lsfd.h
+++ b/misc-utils/lsfd.h
@@ -59,6 +59,9 @@ enum {
 	COL_NLINK,
 	COL_PARTITION,
 	COL_PID,
+	COL_PIDFD_COMM,
+	COL_PIDFD_NSPID,
+	COL_PIDFD_PID,
 	COL_POS,
 	COL_PROTONAME,
 	COL_RDEV,
diff --git a/tests/expected/lsfd/mkfds-pidfd b/tests/expected/lsfd/mkfds-pidfd
index 8fc4b55d70..3f7edbb41f 100644
--- a/tests/expected/lsfd/mkfds-pidfd
+++ b/tests/expected/lsfd/mkfds-pidfd
@@ -1,2 +1,2 @@
-    3   UNKN anon_inodefs pid=1 comm=systemd nspid=1
-ASSOC,STTYPE,SOURCE,NAME: 0
+    3   UNKN anon_inodefs pid=1 comm=systemd nspid=1 systemd            1
+ASSOC,STTYPE,SOURCE,NAME,PIDFD.COMM,PIDFD.PID: 0
diff --git a/tests/ts/lsfd/mkfds-pidfd b/tests/ts/lsfd/mkfds-pidfd
index c707cd1970..fc31bd6b28 100755
--- a/tests/ts/lsfd/mkfds-pidfd
+++ b/tests/ts/lsfd/mkfds-pidfd
@@ -31,13 +31,13 @@ ts_cd "$TS_OUTDIR"
 PID=
 FD=3
 TARGET=1
-EXPR="(PID != ${TARGET}) and (FD == 3)"
+EXPR="(PID != ${TARGET}) and (FD == 3) and (PIDFD.PID == ${TARGET})"
 
 {
     coproc MKFDS { "$TS_HELPER_MKFDS" pidfd $FD target-pid=${TARGET} ; }
     if read -u ${MKFDS[0]} PID; then
-	${TS_CMD_LSFD} -n -o ASSOC,STTYPE,SOURCE,NAME -p "${PID}" -p ${TARGET} -Q "${EXPR}"
-	echo 'ASSOC,STTYPE,SOURCE,NAME': $?
+	${TS_CMD_LSFD} -n -o ASSOC,STTYPE,SOURCE,NAME,PIDFD.COMM,PIDFD.PID -p "${PID}" -p ${TARGET} -Q "${EXPR}"
+	echo 'ASSOC,STTYPE,SOURCE,NAME,PIDFD.COMM,PIDFD.PID': $?
 
 	kill -CONT ${PID}
 	wait ${MKFDS_PID}