X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fzpl_inode.c;h=d9b918b43d92d09bc6c60d2e57661be31672d67d;hb=ebe7e575eae1e03b1faa545a424f008faeac589d;hp=9b5533755985845b5d6cbf3f7c5204ee2965111a;hpb=49be0ccf1fdc2ce852271d4d2f8b7a9c2c4be6db;p=zfs.git

diff --git a/module/zfs/zpl_inode.c b/module/zfs/zpl_inode.c
index 9b55337..d9b918b 100644
--- a/module/zfs/zpl_inode.c
+++ b/module/zfs/zpl_inode.c
@@ -25,6 +25,7 @@
 
 #include <sys/zfs_vfsops.h>
 #include <sys/zfs_vnops.h>
+#include <sys/zfs_znode.h>
 #include <sys/vfs.h>
 #include <sys/zpl.h>
 
@@ -51,7 +52,7 @@ zpl_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 	return d_splice_alias(ip, dentry);
 }
 
-static void
+void
 zpl_vap_init(vattr_t *vap, struct inode *dir, struct dentry *dentry,
     mode_t mode, cred_t *cr)
 {
@@ -171,8 +172,20 @@ zpl_rmdir(struct inode * dir, struct dentry *dentry)
 static int
 zpl_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 {
+	boolean_t issnap = ITOZSB(dentry->d_inode)->z_issnap;
 	int error;
 
+	/*
+	 * Ensure MNT_SHRINKABLE is set on snapshots to ensure they are
+	 * unmounted automatically with the parent file system.  This
+	 * is done on the first getattr because it's not easy to get the
+	 * vfsmount structure at mount time.  This call path is explicitly
+	 * marked unlikely to avoid any performance impact.  FWIW, ext4
+	 * resorts to a similar trick for sysadmin convenience.
+	 */
+	if (unlikely(issnap && !(mnt->mnt_flags & MNT_SHRINKABLE)))
+		mnt->mnt_flags |= MNT_SHRINKABLE;
+
 	error = -zfs_getattr_fast(dentry->d_inode, stat);
 	ASSERT3S(error, <=, 0);