File util-linux-libmount-mount-a-nfs-bind-mount.patch of Package util-linux

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File util-linux-libmount-mount-a-nfs-bind-mount.patch of Package util-linux (Revision b97649f48dcd26939d10337984e01509)

Currently displaying revision b97649f48dcd26939d10337984e01509 , Show latest

From 7966cbba53890e1010861b75bd9923e793bbc975 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.com>
Date: Wed, 18 Apr 2018 13:31:38 +1000
Subject: [PATCH] libmount: fix mnt_table_is_fs_mounted() for NFS bind mounts.

When you bind-mount a subdirectory of a local filesystem, the
path to that subdirectory appears as the fourth field in mountinfo.

For nfs mounts, the fourth field is always "/", and the subdirectory
part is appended to the "special" (aka "device") field.  This is
consistent with historical NFS usage which always includes a path in
the fs_spec field.

libmount needs to know about this when "mount -a" checks to see if
a filesystem is already mounted.

Without this fix, fstab lines like:

server::/path /dir nfs defaults 0 0
 /dir/subdir /mnt/test none bind 0 0

result in a new mount at /mnt/test every time "mount -a" is run.

[kzak@redhat.com: - use strappend() rather than asprintf()]

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
---
 libmount/src/tab.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/libmount/src/tab.c b/libmount/src/tab.c
index 968057e42..eb61dd33e 100644
--- a/libmount/src/tab.c
+++ b/libmount/src/tab.c
@@ -1542,6 +1542,7 @@ int mnt_table_is_fs_mounted(struct libmnt_table *tb, struct libmnt_fs *fstab_fs)
 	struct libmnt_fs *fs;
 
 	char *root = NULL;
+	char *src2 = NULL;
 	const char *src = NULL, *tgt = NULL;
 	char *xtgt = NULL;
 	int rc = 0;
@@ -1566,8 +1567,17 @@ int mnt_table_is_fs_mounted(struct libmnt_table *tb, struct libmnt_fs *fstab_fs)
 			flags = MS_BIND;
 
 		rootfs = mnt_table_get_fs_root(tb, fstab_fs, flags, &root);
-		if (rootfs)
+		if (rootfs) {
+			const char *fstype = mnt_fs_get_fstype(rootfs);
+
 			src = mnt_fs_get_srcpath(rootfs);
+			if (fstype && strncmp(fstype, "nfs", 3) == 0 && root) {
+				/* NFS stores the root at the end of the source */
+				src = src2 = strappend(src, root);
+				free(root);
+				root = NULL;
+			}
+		}
 	}
 
 	if (!src)
@@ -1667,6 +1677,7 @@ done:
 	free(root);
 
 	DBG(TAB, ul_debugobj(tb, "mnt_table_is_fs_mounted: %s [rc=%d]", src, rc));
+	free(src2);
 	return rc;
 }
 
-- 
2.16.3

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File util-linux-libmount-mount-a-nfs-bind-mount.patch of Package util-linux (Revision b97649f48dcd26939d10337984e01509)

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