From f7f29b564073831c9d1a8cdf9deaf039c0bcb1b6 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Thu, 28 Jun 2012 15:40:16 +0200
Subject: [PATCH] libmount: save task ID for mountinfo tiles

Add new function mnt_fs_get_tid() to get task ID for the given filesystem.

Signed-off-by: Karel Zak <kzak@redhat.com>
---
 libmount/src/fs.c          | 18 +++++++++++++++++-
 libmount/src/libmount.h.in |  1 +
 libmount/src/libmount.sym  |  5 +++--
 libmount/src/mountP.h      |  1 +
 libmount/src/tab_parse.c   | 35 +++++++++++++++++++++++++++++++++++
 5 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/libmount/src/fs.c b/libmount/src/fs.c
index 543ffb1537..ff930806fc 100644
--- a/libmount/src/fs.c
+++ b/libmount/src/fs.c
@@ -139,6 +139,7 @@ struct libmnt_fs *mnt_copy_fs(struct libmnt_fs *dest,
 	dest->id         = src->id;
 	dest->parent     = src->parent;
 	dest->devno      = src->devno;
+	dest->tid        = src->tid;
 
 	if (cpy_str_at_offset(dest, src, offsetof(struct libmnt_fs, source)))
 		goto err;
@@ -1157,6 +1158,18 @@ dev_t mnt_fs_get_devno(struct libmnt_fs *fs)
 	return fs ? fs->devno : 0;
 }
 
+/**
+ * mnt_fs_get_tid:
+ * @fs: /proc/<tid>/mountinfo entry
+ *
+ * Returns: TID (task ID) for filesystems read from mountinfo file
+ */
+pid_t mnt_fs_get_tid(struct libmnt_fs *fs)
+{
+	assert(fs);
+	return fs ? fs->tid : 0;
+}
+
 /**
  * mnt_fs_get_option:
  * @fs: fstab/mtab/mountinfo entry pointer
@@ -1406,7 +1419,10 @@ int mnt_fs_print_debug(struct libmnt_fs *fs, FILE *file)
 		fprintf(file, "parent: %d\n", mnt_fs_get_parent_id(fs));
 	if (mnt_fs_get_devno(fs))
 		fprintf(file, "devno:  %d:%d\n", major(mnt_fs_get_devno(fs)),
-						 minor(mnt_fs_get_devno(fs)));
+						minor(mnt_fs_get_devno(fs)));
+	if (mnt_fs_get_tid(fs))
+		fprintf(file, "tid:    %d\n", mnt_fs_get_tid(fs));
+
 	return 0;
 }
 
diff --git a/libmount/src/libmount.h.in b/libmount/src/libmount.h.in
index e122439620..6b87f984c3 100644
--- a/libmount/src/libmount.h.in
+++ b/libmount/src/libmount.h.in
@@ -274,6 +274,7 @@ extern int mnt_fs_set_bindsrc(struct libmnt_fs *fs, const char *src);
 extern int mnt_fs_get_id(struct libmnt_fs *fs);
 extern int mnt_fs_get_parent_id(struct libmnt_fs *fs);
 extern dev_t mnt_fs_get_devno(struct libmnt_fs *fs);
+extern pid_t mnt_fs_get_tid(struct libmnt_fs *fs);
 
 extern const char *mnt_fs_get_swaptype(struct libmnt_fs *fs);
 extern off_t mnt_fs_get_size(struct libmnt_fs *fs);
diff --git a/libmount/src/libmount.sym b/libmount/src/libmount.sym
index d4d5b84bf4..d07b570f14 100644
--- a/libmount/src/libmount.sym
+++ b/libmount/src/libmount.sym
@@ -239,8 +239,9 @@ global:
 	mnt_table_parse_swaps;
 	mnt_get_mountpoint;
 	mnt_get_swaps_path;
-	mnt_fs_get_swaptype;
+	mnt_fs_get_priority;
 	mnt_fs_get_size;
+	mnt_fs_get_swaptype;
+	mnt_fs_get_tid;
 	mnt_fs_get_usedsize;
-	mnt_fs_get_priority;
 } MOUNT_2.21;
diff --git a/libmount/src/mountP.h b/libmount/src/mountP.h
index f7cd7d53dd..a2922c2b3e 100644
--- a/libmount/src/mountP.h
+++ b/libmount/src/mountP.h
@@ -218,6 +218,7 @@ struct libmnt_fs {
 	int		priority;	/* swaps[5]: swap priority */
 
 	int		flags;		/* MNT_FS_* flags */
+	pid_t		tid;		/* /proc/<tid>/mountinfo otherwise zero */
 
 	void		*userdata;	/* library independent data */
 };
diff --git a/libmount/src/tab_parse.c b/libmount/src/tab_parse.c
index 73a7f83c8b..ab5d51acd4 100644
--- a/libmount/src/tab_parse.c
+++ b/libmount/src/tab_parse.c
@@ -423,6 +423,35 @@ err:
 	return tb->errcb ? tb->errcb(tb, filename, *nlines) : 1;
 }
 
+static pid_t path_to_tid(const char *filename)
+{
+	char *path = mnt_resolve_path(filename, NULL);
+	char *p, *end = NULL;
+	pid_t tid = 0;
+
+	if (!path)
+		goto done;
+	p = strrchr(path, '/');
+	if (!p)
+		goto done;
+	*p = '\0';
+	p = strrchr(path, '/');
+	if (!p)
+		goto done;
+	p++;
+
+	errno = 0;
+	tid = strtol(p, &end, 10);
+	if (errno || p == end || (end && *end)) {
+		tid = 0;
+		goto done;
+	}
+	DBG(TAB, mnt_debug("TID for %s is %d", filename, tid));
+done:
+	free(path);
+	return tid;
+}
+
 /**
  * mnt_table_parse_stream:
  * @tb: tab pointer
@@ -436,6 +465,7 @@ int mnt_table_parse_stream(struct libmnt_table *tb, FILE *f, const char *filenam
 	int nlines = 0;
 	int rc = -1;
 	int flags = 0;
+	pid_t tid = -1;
 
 	assert(tb);
 	assert(f);
@@ -460,6 +490,11 @@ int mnt_table_parse_stream(struct libmnt_table *tb, FILE *f, const char *filenam
 		if (!rc) {
 			rc = mnt_table_add_fs(tb, fs);
 			fs->flags |= flags;
+			if (tb->fmt == MNT_FMT_MOUNTINFO && filename) {
+				if (tid == -1)
+					tid = path_to_tid(filename);
+				fs->tid = tid;
+			}
 		}
 		if (rc) {
 			mnt_free_fs(fs);
-- 
2.47.3