1 files changed, 136 insertions, 7 deletions

diff --git a/fs/super.c b/fs/super.c
index 5960578a4076..8020974b2a68 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -32,6 +32,7 @@
 #include <linux/backing-dev.h>
 #include <linux/rculist_bl.h>
 #include <linux/cleancache.h>
+#include <linux/fscrypt.h>
 #include <linux/fsnotify.h>
 #include <linux/lockdep.h>
 #include <linux/user_namespace.h>
@@ -257,6 +258,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags,
 	s->s_maxbytes = MAX_NON_LFS;
 	s->s_op = &default_op;
 	s->s_time_gran = 1000000000;
+	s->s_time_min = TIME64_MIN;
+	s->s_time_max = TIME64_MAX;
 	s->cleancache_poolid = CLEANCACHE_NO_POOL;
 
 	s->s_shrink.seeks = DEFAULT_SEEKS;
@@ -290,6 +293,7 @@ static void __put_super(struct super_block *s)
 		WARN_ON(s->s_inode_lru.node);
 		WARN_ON(!list_empty(&s->s_mounts));
 		security_sb_free(s);
+		fscrypt_sb_free(s);
 		put_user_ns(s->s_user_ns);
 		kfree(s->s_subtype);
 		call_rcu(&s->rcu, destroy_super_rcu);
@@ -1160,9 +1164,11 @@ int vfs_get_super(struct fs_context *fc,
 {
 	int (*test)(struct super_block *, struct fs_context *);
 	struct super_block *sb;
+	int err;
 
 	switch (keying) {
 	case vfs_get_single_super:
+	case vfs_get_single_reconf_super:
 		test = test_single_super;
 		break;
 	case vfs_get_keyed_super:
@@ -1180,18 +1186,29 @@ int vfs_get_super(struct fs_context *fc,
 		return PTR_ERR(sb);
 
 	if (!sb->s_root) {
-		int err = fill_super(sb, fc);
-		if (err) {
-			deactivate_locked_super(sb);
-			return err;
-		}
+		err = fill_super(sb, fc);
+		if (err)
+			goto error;
 
 		sb->s_flags |= SB_ACTIVE;
+		fc->root = dget(sb->s_root);
+	} else {
+		fc->root = dget(sb->s_root);
+		if (keying == vfs_get_single_reconf_super) {
+			err = reconfigure_super(fc);
+			if (err < 0) {
+				dput(fc->root);
+				fc->root = NULL;
+				goto error;
+			}
+		}
 	}
 
-	BUG_ON(fc->root);
-	fc->root = dget(sb->s_root);
 	return 0;
+
+error:
+	deactivate_locked_super(sb);
+	return err;
 }
 EXPORT_SYMBOL(vfs_get_super);
 
@@ -1211,7 +1228,26 @@ int get_tree_single(struct fs_context *fc,
 }
 EXPORT_SYMBOL(get_tree_single);
 
+int get_tree_single_reconf(struct fs_context *fc,
+		  int (*fill_super)(struct super_block *sb,
+				    struct fs_context *fc))
+{
+	return vfs_get_super(fc, vfs_get_single_reconf_super, fill_super);
+}
+EXPORT_SYMBOL(get_tree_single_reconf);
+
+int get_tree_keyed(struct fs_context *fc,
+		  int (*fill_super)(struct super_block *sb,
+				    struct fs_context *fc),
+		void *key)
+{
+	fc->s_fs_info = key;
+	return vfs_get_super(fc, vfs_get_keyed_super, fill_super);
+}
+EXPORT_SYMBOL(get_tree_keyed);
+
 #ifdef CONFIG_BLOCK
+
 static int set_bdev_super(struct super_block *s, void *data)
 {
 	s->s_bdev = data;
@@ -1221,6 +1257,99 @@ static int set_bdev_super(struct super_block *s, void *data)
 	return 0;
 }
 
+static int set_bdev_super_fc(struct super_block *s, struct fs_context *fc)
+{
+	return set_bdev_super(s, fc->sget_key);
+}
+
+static int test_bdev_super_fc(struct super_block *s, struct fs_context *fc)
+{
+	return s->s_bdev == fc->sget_key;
+}
+
+/**
+ * get_tree_bdev - Get a superblock based on a single block device
+ * @fc: The filesystem context holding the parameters
+ * @fill_super: Helper to initialise a new superblock
+ */
+int get_tree_bdev(struct fs_context *fc,
+		int (*fill_super)(struct super_block *,
+				  struct fs_context *))
+{
+	struct block_device *bdev;
+	struct super_block *s;
+	fmode_t mode = FMODE_READ | FMODE_EXCL;
+	int error = 0;
+
+	if (!(fc->sb_flags & SB_RDONLY))
+		mode |= FMODE_WRITE;
+
+	if (!fc->source)
+		return invalf(fc, "No source specified");
+
+	bdev = blkdev_get_by_path(fc->source, mode, fc->fs_type);
+	if (IS_ERR(bdev)) {
+		errorf(fc, "%s: Can't open blockdev", fc->source);
+		return PTR_ERR(bdev);
+	}
+
+	/* Once the superblock is inserted into the list by sget_fc(), s_umount
+	 * will protect the lockfs code from trying to start a snapshot while
+	 * we are mounting
+	 */
+	mutex_lock(&bdev->bd_fsfreeze_mutex);
+	if (bdev->bd_fsfreeze_count > 0) {
+		mutex_unlock(&bdev->bd_fsfreeze_mutex);
+		warnf(fc, "%pg: Can't mount, blockdev is frozen", bdev);
+		return -EBUSY;
+	}
+
+	fc->sb_flags |= SB_NOSEC;
+	fc->sget_key = bdev;
+	s = sget_fc(fc, test_bdev_super_fc, set_bdev_super_fc);
+	mutex_unlock(&bdev->bd_fsfreeze_mutex);
+	if (IS_ERR(s))
+		return PTR_ERR(s);
+
+	if (s->s_root) {
+		/* Don't summarily change the RO/RW state. */
+		if ((fc->sb_flags ^ s->s_flags) & SB_RDONLY) {
+			warnf(fc, "%pg: Can't mount, would change RO state", bdev);
+			deactivate_locked_super(s);
+			blkdev_put(bdev, mode);
+			return -EBUSY;
+		}
+
+		/*
+		 * s_umount nests inside bd_mutex during
+		 * __invalidate_device().  blkdev_put() acquires
+		 * bd_mutex and can't be called under s_umount.  Drop
+		 * s_umount temporarily.  This is safe as we're
+		 * holding an active reference.
+		 */
+		up_write(&s->s_umount);
+		blkdev_put(bdev, mode);
+		down_write(&s->s_umount);
+	} else {
+		s->s_mode = mode;
+		snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
+		sb_set_blocksize(s, block_size(bdev));
+		error = fill_super(s, fc);
+		if (error) {
+			deactivate_locked_super(s);
+			return error;
+		}
+
+		s->s_flags |= SB_ACTIVE;
+		bdev->bd_super = s;
+	}
+
+	BUG_ON(fc->root);
+	fc->root = dget(s->s_root);
+	return 0;
+}
+EXPORT_SYMBOL(get_tree_bdev);
+
 static int test_bdev_super(struct super_block *s, void *data)
 {
 	return (void *)s->s_bdev == data;