From 31d6d5ce53400d6dc58e29ddd8dc184b3ba89d66 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 25 Mar 2019 16:38:23 +0000 Subject: vfs: Provide a mount_pseudo-replacement for the new mount API Provide a function, init_pseudo(), that provides a common infrastructure for converting pseudo-filesystems that can never be mountable. [AV: once all users of mount_pseudo_xattr() get converted, it will be folded into pseudo_fs_get_tree()] Signed-off-by: David Howells cc: linux-fsdevel@vger.kernel.org --- fs/libfs.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'fs/libfs.c') diff --git a/fs/libfs.c b/fs/libfs.c index 030e545f586e..edef70d35438 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -16,6 +16,8 @@ #include #include #include /* sync_mapping_buffers */ +#include +#include #include @@ -235,6 +237,50 @@ static const struct super_operations simple_super_operations = { .statfs = simple_statfs, }; +static int pseudo_fs_get_tree(struct fs_context *fc) +{ + struct pseudo_fs_context *ctx = fc->fs_private; + struct dentry *root; + + root = mount_pseudo_xattr(fc->fs_type, + ctx->ops, ctx->xattr, + ctx->dops, ctx->magic); + if (IS_ERR(root)) + return PTR_ERR(root); + + fc->root = root; + return 0; +} + +static void pseudo_fs_free(struct fs_context *fc) +{ + kfree(fc->fs_private); +} + +static const struct fs_context_operations pseudo_fs_context_ops = { + .free = pseudo_fs_free, + .get_tree = pseudo_fs_get_tree, +}; + +/* + * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that + * will never be mountable) + */ +struct pseudo_fs_context *init_pseudo(struct fs_context *fc, + unsigned long magic) +{ + struct pseudo_fs_context *ctx; + + ctx = kzalloc(sizeof(struct pseudo_fs_context), GFP_KERNEL); + if (likely(ctx)) { + ctx->magic = magic; + fc->fs_private = ctx; + fc->ops = &pseudo_fs_context_ops; + } + return ctx; +} +EXPORT_SYMBOL(init_pseudo); + /* * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that * will never be mountable) -- cgit