From: Marcos Paulo de Souza <marcos@mpdesouza.com>
To: dsterba@suse.com, linux-btrfs@vger.kernel.org
Cc: Marcos Paulo de Souza <mpdesouza@suse.com>
Subject: [RFC PATCH 6/8] btrfs: super: Introduce btrfs_mount_root_fc
Date: Wed, 12 Aug 2020 13:36:52 -0300 [thread overview]
Message-ID: <20200812163654.17080-7-marcos@mpdesouza.com> (raw)
In-Reply-To: <20200812163654.17080-1-marcos@mpdesouza.com>
From: Marcos Paulo de Souza <mpdesouza@suse.com>
This function will be used by the following patches to mount the root fs
before mounting a subvolume.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
---
fs/btrfs/super.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 6b70fb73a1ea..5bbf4b947125 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2419,6 +2419,47 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
return ERR_PTR(error);
}
+/*
+ * Duplicate the current fc and prepare for mounting the root.
+ * btrfs_get_tree will be called recursively, but then will check for the
+ * ctx->root being set and call btrfs_root_get_tree.
+ */
+static int btrfs_mount_root_fc(struct fs_context *fc, unsigned int rdonly)
+{
+ struct btrfs_fs_context *ctx, *root_ctx;
+ struct fs_context *root_fc;
+ struct vfsmount *root_mnt;
+ int ret;
+
+ root_fc = vfs_dup_fs_context(fc);
+ if (IS_ERR(root_fc))
+ return PTR_ERR(root_fc);
+
+ root_fc->sb_flags &= ~SB_RDONLY;
+ root_fc->sb_flags |= rdonly | SB_NOSEC;
+ root_ctx = root_fc->fs_private;
+ root_ctx->root_mnt = NULL;
+ root_ctx->root = true;
+
+ /*
+ * fc_mount will call btrfs_get_tree again, and by checking ctx->root
+ * being true it'll call btrfs_root_get_tree to avoid infinite recursion.
+ */
+ root_mnt = fc_mount(root_fc);
+ if (IS_ERR(root_mnt)) {
+ ret = PTR_ERR(root_mnt);
+ goto error_fc;
+ }
+
+ ctx = fc->fs_private;
+ ctx->root_mnt = root_mnt;
+ ret = 0;
+
+error_fc:
+ put_fs_context(root_fc);
+ return ret;
+}
+
/*
* Mount function which is called by VFS layer.
*
--
2.28.0
next prev parent reply other threads:[~2020-08-12 17:02 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-12 16:36 [RFC PATCH 0/8] btrfs: convert to fscontext Marcos Paulo de Souza
2020-08-12 16:36 ` [RFC PATCH 1/8] btrfs: fs_context: Add initial fscontext parameters Marcos Paulo de Souza
2020-08-12 16:36 ` [RFC PATCH 2/8] btrfs: super: Introduce fs_context ops, init and free functions Marcos Paulo de Souza
2020-08-17 12:50 ` David Sterba
2020-08-12 16:36 ` [RFC PATCH 3/8] btrfs: super: Introduce btrfs_fc_parse_param and btrfs_apply_configuration Marcos Paulo de Souza
2020-08-17 13:09 ` David Sterba
2020-08-12 16:36 ` [RFC PATCH 4/8] btrfs: super: Introduce btrfs_fc_validate Marcos Paulo de Souza
2020-08-12 16:36 ` [RFC PATCH 5/8] btrfs: super: Introduce btrfs_dup_fc Marcos Paulo de Souza
2020-08-12 16:36 ` Marcos Paulo de Souza [this message]
2020-08-17 13:14 ` [RFC PATCH 6/8] btrfs: super: Introduce btrfs_mount_root_fc David Sterba
2020-08-12 16:36 ` [RFC PATCH 7/8] btrfs: Convert to fs_context Marcos Paulo de Souza
2020-08-17 13:26 ` David Sterba
2020-08-12 16:36 ` [RFC PATCH 8/8] btrfs: Remove leftover code from fscontext conversion Marcos Paulo de Souza
2020-08-17 12:44 ` [RFC PATCH 0/8] btrfs: convert to fscontext David Sterba
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