From: Masatake YAMATO <yamato@redhat.com>
Date: Fri, 9 Jun 2023 05:55:05 +0000 (+0900)
Subject: lsfd: fill NAME column of inotify files with the information about their monitoring... 
X-Git-Tag: v2.40-rc1~389^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c1a26ac8f13eb1a485699fa2fd910d952bbf8369;p=thirdparty%2Futil-linux.git

lsfd: fill NAME column of inotify files with the information about their monitoring targets

    # ./lsfd  -p 1  -Q '(TYPE == "inotify") and (FD > 7)'
    COMMAND PID USER ASSOC MODE    TYPE       SOURCE MNTID INODE NAME
    systemd   1 root    11  r-- inotify anon_inodefs    15  1060 inodes=116@dm-0
    systemd   1 root    13  r-- inotify anon_inodefs    15  1060 inodes=299@tmpfs
    systemd   1 root    19  r-- inotify anon_inodefs    15  1060 inodes=41@tmpfs,2@tmpfs,1@tmpfs,96@dm-0
    systemd   1 root    21  r-- inotify anon_inodefs    15  1060 inodes=41@tmpfs,2@tmpfs,1@tmpfs,96@dm-0

In addition, INOTIFY.INODES and INOTIFY.INODES.RAW column are added.

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

diff --git a/misc-utils/lsfd-unkn.c b/misc-utils/lsfd-unkn.c
index 8b8320bb18..0045a6a472 100644
--- a/misc-utils/lsfd-unkn.c
+++ b/misc-utils/lsfd-unkn.c
@@ -809,6 +809,148 @@ static const struct anon_ops anon_signalfd_ops = {
 	.handle_fdinfo = anon_signalfd_handle_fdinfo,
 };
 
+/*
+ * inotify
+ */
+struct anon_inotify_data {
+	struct list_head inodes;
+};
+
+struct anon_inotify_inode {
+	ino_t ino;
+	dev_t sdev;
+	struct list_head inodes;
+};
+
+static bool anon_inotify_probe(const char *str)
+{
+	return strncmp(str, "inotify", 7) == 0;
+}
+
+/* A device number appeared in fdinfo of an inotify file uses the kernel
+ * internal representation. It is different from what we are familiar with;
+ * major(3) and minor(3) don't work with the representation.
+ * See linux/include/linux/kdev_t.h. */
+#define ANON_INOTIFY_MINORBITS	20
+#define ANON_INOTIFY_MINORMASK	((1U << ANON_INOTIFY_MINORBITS) - 1)
+
+#define ANON_INOTIFY_MAJOR(dev)	((unsigned int) ((dev) >> ANON_INOTIFY_MINORBITS))
+#define ANON_INOTIFY_MINOR(dev)	((unsigned int) ((dev) &  ANON_INOTIFY_MINORMASK))
+
+static char *anon_inotify_make_inodes_string(const char *prefix,
+					     enum decode_source_level decode_level,
+					     struct anon_inotify_data *data)
+{
+	char *str = NULL;
+	char buf[BUFSIZ] = {'\0'};
+	bool first_element = true;
+
+	struct list_head *i;
+	list_for_each(i, &data->inodes) {
+		char source[BUFSIZ/2] = {'\0'};
+		struct anon_inotify_inode *inode = list_entry(i,
+							      struct anon_inotify_inode,
+							      inodes);
+
+		decode_source(source, sizeof(source),
+			      ANON_INOTIFY_MAJOR(inode->sdev), ANON_INOTIFY_MINOR(inode->sdev),
+			      decode_level);
+		snprintf(buf, sizeof(buf), "%s%llu@%s", first_element? prefix: ",",
+			 (unsigned long long)inode->ino, source);
+		first_element = false;
+
+		xstrappend(&str, buf);
+	}
+
+	return str;
+}
+
+static char *anon_inotify_get_name(struct unkn *unkn)
+{
+	return anon_inotify_make_inodes_string("inodes=", DECODE_SOURCE_FULL,
+					       (struct anon_inotify_data *)unkn->anon_data);
+}
+
+static void anon_inotify_init(struct unkn *unkn)
+{
+	struct anon_inotify_data *data = xcalloc(1, sizeof(struct anon_inotify_data));
+	INIT_LIST_HEAD (&data->inodes);
+	unkn->anon_data = data;
+}
+
+static void anon_inotify_free(struct unkn *unkn)
+{
+	struct anon_inotify_data *data = unkn->anon_data;
+
+	list_free(&data->inodes, struct anon_inotify_inode, inodes,
+		  free);
+	free(data);
+}
+
+static void add_inode(struct anon_inotify_data *data, ino_t ino, dev_t sdev)
+{
+	struct anon_inotify_inode *inode = xmalloc(sizeof(*inode));
+
+	INIT_LIST_HEAD (&inode->inodes);
+	inode->ino = ino;
+	inode->sdev = sdev;
+
+	list_add_tail(&inode->inodes, &data->inodes);
+}
+
+static int anon_inotify_handle_fdinfo(struct unkn *unkn, const char *key, const char *value)
+{
+	struct anon_inotify_data *data = (struct anon_inotify_data *)unkn->anon_data;
+
+	if (strcmp(key, "inotify wd") == 0) {
+		unsigned long long ino;
+		unsigned long long sdev;
+
+		if (sscanf(value, "%*d ino:%llx sdev:%llx %*s", &ino, &sdev) == 2) {
+			add_inode(data, (ino_t)ino, (dev_t)sdev);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static bool anon_inotify_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_inotify_data *data = (struct anon_inotify_data *)unkn->anon_data;
+
+	switch(column_id) {
+	case COL_INOTIFY_INODES:
+		*str = anon_inotify_make_inodes_string("", DECODE_SOURCE_FULL,
+						       data);
+		if (*str)
+			return true;
+		break;
+	case COL_INOTIFY_INODES_RAW:
+		*str = anon_inotify_make_inodes_string("", DECODE_SOURCE_MAJMIN,
+						       data);
+		if (*str)
+			return true;
+		break;
+	}
+
+	return false;
+}
+
+static const struct anon_ops anon_inotify_ops = {
+	.class = "inotify",
+	.probe = anon_inotify_probe,
+	.get_name = anon_inotify_get_name,
+	.fill_column = anon_inotify_fill_column,
+	.init = anon_inotify_init,
+	.free = anon_inotify_free,
+	.handle_fdinfo = anon_inotify_handle_fdinfo,
+};
+
 /*
  * generic (fallback implementation)
  */
@@ -827,6 +969,7 @@ static const struct anon_ops *anon_ops[] = {
 	&anon_eventpoll_ops,
 	&anon_timerfd_ops,
 	&anon_signalfd_ops,
+	&anon_inotify_ops,
 };
 
 static const struct anon_ops *anon_probe(const char *str)
diff --git a/misc-utils/lsfd.1.adoc b/misc-utils/lsfd.1.adoc
index 1317741925..c26d2a7da7 100644
--- a/misc-utils/lsfd.1.adoc
+++ b/misc-utils/lsfd.1.adoc
@@ -194,6 +194,15 @@ Remote IP6 address.
 INODE <``number``>::
 Inode number.
 
+INOTIFY.INODES <``string``>::
+Cooked version of INOTIFY.INODES.RAW.
+The format of the element is
+_inode-number_,_source-of-inode_.
+
+INOTIFY.INODES.RAW <``string``>::
+List of monitoring inodes. The format of the element
+is _inode-number_,_device-major_:_device-minor_.
+
 KNAME <``string``>::
 //
 // It seems that the manpage backend of asciidoctor has limitations
@@ -235,6 +244,9 @@ tfds=_EVENTPOLL.TFDS_
 eventfd:::
 id=_EVENTFD.ID_
 +
+inotify:::
+iodes=_INOTIFY.INODES_
++
 NETLINK:::
 protocol=_NETLINK.PROTOCOL_[ lport=_NETLINK.LPORT_[ group=_NETLINK.GROUPS_]]
 +
diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index 590787bf43..15280407c5 100644
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -177,6 +177,12 @@ static const struct colinfo infos[] = {
 	[COL_INODE]            = { "INODE",
 				   0,   SCOLS_FL_RIGHT, SCOLS_JSON_NUMBER,
 				   N_("inode number") },
+	[COL_INOTIFY_INODES]   = { "INOTIFY.INODES",
+				   0,   SCOLS_FL_WRAP,  SCOLS_JSON_STRING,
+				   N_("list of monitoring inodes (cooked)") },
+	[COL_INOTIFY_INODES_RAW]={ "INOTIFY.INODES.RAW",
+				   0,   SCOLS_FL_WRAP,  SCOLS_JSON_STRING,
+				   N_("list of monitoring inodes (raw, don't decode devices)") },
 	[COL_KNAME]            = { "KNAME",
 				   0.4, SCOLS_FL_TRUNC, SCOLS_JSON_STRING,
 				   N_("name of the file (raw)") },
diff --git a/misc-utils/lsfd.h b/misc-utils/lsfd.h
index f300c0cc22..1b86b625b3 100644
--- a/misc-utils/lsfd.h
+++ b/misc-utils/lsfd.h
@@ -56,6 +56,8 @@ enum {
 	COL_INET6_LADDR,
 	COL_INET6_RADDR,
 	COL_INODE,
+	COL_INOTIFY_INODES,
+	COL_INOTIFY_INODES_RAW,
 	COL_KNAME,
 	COL_KTHREAD,
 	COL_MAJMIN,