[PATCH 3/4] xfs_fsr: refactor mountpoint finding to use libfrog paths functions

["Darrick J. Wong" <darrick.wong@oracle.com>]

From: Darrick J. Wong <darrick.wong@oracle.com>

Refactor the mount-point finding code in fsr to use the libfrog helpers
instead of open-coding yet another routine.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fsr/Makefile    |    4 ++-
 fsr/xfs_fsr.c   |   71 +++++--------------------------------------------------
 include/path.h  |    1 +
 libfrog/paths.c |   47 ++++++++++++++++++++++++++++--------
 4 files changed, 47 insertions(+), 76 deletions(-)


diff --git a/fsr/Makefile b/fsr/Makefile
index d3521b2..fc1c33b 100644
--- a/fsr/Makefile
+++ b/fsr/Makefile
@@ -7,7 +7,9 @@ include $(TOPDIR)/include/builddefs
 
 LTCOMMAND = xfs_fsr
 CFILES = xfs_fsr.c
-LLDLIBS = $(LIBHANDLE)
+LLDLIBS = $(LIBHANDLE) $(LIBFROG)
+LTDEPENDENCIES = $(LIBFROG)
+LLDFLAGS = -static-libtool-libs
 
 ifeq ($(HAVE_GETMNTENT),yes)
 LCFLAGS += -DHAVE_GETMNTENT
diff --git a/fsr/xfs_fsr.c b/fsr/xfs_fsr.c
index 2a18ce0..ef6a68f 100644
--- a/fsr/xfs_fsr.c
+++ b/fsr/xfs_fsr.c
@@ -22,6 +22,7 @@
 #include "jdm.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_attr_sf.h"
+#include "path.h"
 
 #include <fcntl.h>
 #include <errno.h>
@@ -167,73 +168,13 @@ aborter(int unused)
 	exit(1);
 }
 
-/*
- * Check if the argument is either the device name or mountpoint of an XFS
- * filesystem.  Note that we do not care about bind mounted regular files
- * here - the code that handles defragmentation of invidual files takes care
- * of that.
- */
-static char *
-find_mountpoint_check(struct stat *sb, struct mntent *t)
-{
-	struct stat ms;
-
-	if (S_ISDIR(sb->st_mode)) {		/* mount point */
-		if (stat(t->mnt_dir, &ms) < 0)
-			return NULL;
-		if (sb->st_ino != ms.st_ino)
-			return NULL;
-		if (sb->st_dev != ms.st_dev)
-			return NULL;
-		if (strcmp(t->mnt_type, MNTTYPE_XFS) != 0)
-			return NULL;
-	} else {				/* device */
-		if (stat(t->mnt_fsname, &ms) < 0)
-			return NULL;
-		if (sb->st_rdev != ms.st_rdev)
-			return NULL;
-		if (strcmp(t->mnt_type, MNTTYPE_XFS) != 0)
-			return NULL;
-		/*
-		 * Make sure the mountpoint given by mtab is accessible
-		 * before using it.
-		 */
-		if (stat(t->mnt_dir, &ms) < 0)
-			return NULL;
-	}
-
-	return t->mnt_dir;
-}
-
-static char *
-find_mountpoint(char *mtab, char *argname, struct stat *sb)
-{
-	struct mntent_cursor cursor;
-	struct mntent *t = NULL;
-	char *mntp = NULL;
-
-	if (platform_mntent_open(&cursor, mtab) != 0){
-		fprintf(stderr, "Error: can't get mntent entries.\n");
-		exit(1);
-	}
-
-	while ((t = platform_mntent_next(&cursor)) != NULL) {
-		mntp = find_mountpoint_check(sb, t);
-		if (mntp == NULL)
-			continue;
-		break;
-	}
-	platform_mntent_close(&cursor);
-	return mntp;
-}
-
 int
 main(int argc, char **argv)
 {
 	struct stat sb;
 	char *argname;
 	int c;
-	char *mntp;
+	struct fs_path	*fsp;
 	char *mtab = NULL;
 
 	setlinebuf(stdout);
@@ -343,9 +284,11 @@ main(int argc, char **argv)
 				sb = sb2;
 			}
 
-			mntp = find_mountpoint(mtab, argname, &sb);
-			if (mntp != NULL) {
-				fsrfs(mntp, 0, 100);
+			fsp = fs_table_lookup_mount(argname);
+			if (!fsp)
+				fsp = fs_table_lookup_blkdev(argname);
+			if (fsp != NULL) {
+				fsrfs(fsp->fs_dir, 0, 100);
 			} else if (S_ISCHR(sb.st_mode)) {
 				fprintf(stderr, _(
 					"%s: char special not supported: %s\n"),
diff --git a/include/path.h b/include/path.h
index 1d3a902..88dc44b 100644
--- a/include/path.h
+++ b/include/path.h
@@ -57,6 +57,7 @@ extern void fs_table_insert_project_path(char *__dir, uint __projid);
 
 extern fs_path_t *fs_table_lookup(const char *__dir, uint __flags);
 extern fs_path_t *fs_table_lookup_mount(const char *__dir);
+extern fs_path_t *fs_table_lookup_blkdev(const char *bdev);
 
 typedef struct fs_cursor {
 	uint		count;		/* total count of mount entries	*/
diff --git a/libfrog/paths.c b/libfrog/paths.c
index 19ee1ea..a80a30b 100644
--- a/libfrog/paths.c
+++ b/libfrog/paths.c
@@ -89,15 +89,10 @@ fs_table_lookup(
 	return NULL;
 }
 
-/*
- * Find the FS table entry describing an actual mount for the given path.
- * Unlike fs_table_lookup(), fs_table_lookup_mount() compares the "dir"
- * argument to actual mount point entries in the table. Accordingly, it
- * will find matches only if the "dir" argument is indeed mounted.
- */
-struct fs_path *
-fs_table_lookup_mount(
-	const char	*dir)
+static struct fs_path *
+__fs_table_lookup_mount(
+	const char	*dir,
+	const char	*blkdev)
 {
 	uint		i;
 	dev_t		dev = 0;
@@ -106,13 +101,17 @@ fs_table_lookup_mount(
 
 	if (fs_device_number(dir, &dev))
 		return NULL;
-	if (!realpath(dir, dpath))
+	if (dir && !realpath(dir, dpath))
+		return NULL;
+	if (blkdev && !realpath(blkdev, dpath))
 		return NULL;
 
 	for (i = 0; i < fs_count; i++) {
 		if (fs_table[i].fs_flags != FS_MOUNT_POINT)
 			continue;
-		if (!realpath(fs_table[i].fs_dir, rpath))
+		if (dir && !realpath(fs_table[i].fs_dir, rpath))
+			continue;
+		if (blkdev && !realpath(fs_table[i].fs_name, rpath))
 			continue;
 		if (strcmp(rpath, dpath) == 0)
 			return &fs_table[i];
@@ -120,6 +119,32 @@ fs_table_lookup_mount(
 	return NULL;
 }
 
+/*
+ * Find the FS table entry describing an actual mount for the given path.
+ * Unlike fs_table_lookup(), fs_table_lookup_mount() compares the "dir"
+ * argument to actual mount point entries in the table. Accordingly, it
+ * will find matches only if the "dir" argument is indeed mounted.
+ */
+struct fs_path *
+fs_table_lookup_mount(
+	const char	*dir)
+{
+	return __fs_table_lookup_mount(dir, NULL);
+}
+
+/*
+ * Find the FS table entry describing an actual mount for the block device.
+ * Unlike fs_table_lookup(), fs_table_lookup_blkdev() compares the "bdev"
+ * argument to actual mount point names in the table. Accordingly, it
+ * will find matches only if the "bdev" argument is indeed mounted.
+ */
+struct fs_path *
+fs_table_lookup_blkdev(
+	const char	*bdev)
+{
+	return __fs_table_lookup_mount(NULL, bdev);
+}
+
 static int
 fs_table_insert(
 	char		*dir,