Commit 0158005a authored by Al Viro's avatar Al Viro
Browse files

replace do_getxattr() with saner helpers. 



similar to do_setxattr() in the previous commit...

Reviewed-by: default avatarChristian Brauner <brauner@kernel.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 66d7ac6b

fs/internal.h

+3 −5
Original line number Diff line number Diff line
@@ -280,11 +280,9 @@ struct kernel_xattr_ctx { 
	unsigned int flags;

};





ssize_t do_getxattr(struct mnt_idmap *idmap,

		    struct dentry *d,

		    struct kernel_xattr_ctx *ctx);



ssize_t file_getxattr(struct file *file, struct kernel_xattr_ctx *ctx);

ssize_t filename_getxattr(int dfd, struct filename *filename,

			  unsigned int lookup_flags, struct kernel_xattr_ctx *ctx);

int file_setxattr(struct file *file, struct kernel_xattr_ctx *ctx);

int filename_setxattr(int dfd, struct filename *filename,

		      unsigned int lookup_flags, struct kernel_xattr_ctx *ctx);

fs/xattr.c

+51 −37
Original line number Diff line number Diff line
@@ -744,27 +744,28 @@ SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, 
/*

 * Extended attribute GET operations

 */

ssize_t

static ssize_t

do_getxattr(struct mnt_idmap *idmap, struct dentry *d,

	struct kernel_xattr_ctx *ctx)

{

	ssize_t error;

	char *kname = ctx->kname->name;

	void *kvalue = NULL;



	if (ctx->size) {

		if (ctx->size > XATTR_SIZE_MAX)

			ctx->size = XATTR_SIZE_MAX;

		ctx->kvalue = kvzalloc(ctx->size, GFP_KERNEL);

		if (!ctx->kvalue)

		kvalue = kvzalloc(ctx->size, GFP_KERNEL);

		if (!kvalue)

			return -ENOMEM;

	}



	if (is_posix_acl_xattr(ctx->kname->name))

		error = do_get_acl(idmap, d, kname, ctx->kvalue, ctx->size);

	if (is_posix_acl_xattr(kname))

		error = do_get_acl(idmap, d, kname, kvalue, ctx->size);

	else

		error = vfs_getxattr(idmap, d, kname, ctx->kvalue, ctx->size);

		error = vfs_getxattr(idmap, d, kname, kvalue, ctx->size);

	if (error > 0) {

		if (ctx->size && copy_to_user(ctx->value, ctx->kvalue, error))

		if (ctx->size && copy_to_user(ctx->value, kvalue, error))

			error = -EFAULT;

	} else if (error == -ERANGE && ctx->size >= XATTR_SIZE_MAX) {

		/* The file system tried to returned a value bigger
@@ -772,52 +773,56 @@ do_getxattr(struct mnt_idmap *idmap, struct dentry *d, 
		error = -E2BIG;

	}



	kvfree(kvalue);

	return error;

}



static ssize_t

getxattr(struct mnt_idmap *idmap, struct dentry *d,

	 const char __user *name, void __user *value, size_t size)

ssize_t file_getxattr(struct file *f, struct kernel_xattr_ctx *ctx)

{

	ssize_t error;

	struct xattr_name kname;

	struct kernel_xattr_ctx ctx = {

		.value    = value,

		.kvalue   = NULL,

		.size     = size,

		.kname    = &kname,

		.flags    = 0,

	};



	error = import_xattr_name(&kname, name);

	if (error)

		return error;



	error =  do_getxattr(idmap, d, &ctx);



	kvfree(ctx.kvalue);

	return error;

	audit_file(f);

	return do_getxattr(file_mnt_idmap(f), f->f_path.dentry, ctx);

}



static ssize_t path_getxattr(const char __user *pathname,

			     const char __user *name, void __user *value,

			     size_t size, unsigned int lookup_flags)

/* unconditionally consumes filename */

ssize_t filename_getxattr(int dfd, struct filename *filename,

			  unsigned int lookup_flags, struct kernel_xattr_ctx *ctx)

{

	struct path path;

	ssize_t error;

retry:

	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);

	error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);

	if (error)

		return error;

	error = getxattr(mnt_idmap(path.mnt), path.dentry, name, value, size);

		goto out;

	error = do_getxattr(mnt_idmap(path.mnt), path.dentry, ctx);

	path_put(&path);

	if (retry_estale(error, lookup_flags)) {

		lookup_flags |= LOOKUP_REVAL;

		goto retry;

	}

out:

	putname(filename);

	return error;

}



static ssize_t path_getxattr(const char __user *pathname,

			     const char __user *name, void __user *value,

			     size_t size, unsigned int lookup_flags)

{

	ssize_t error;

	struct xattr_name kname;

	struct kernel_xattr_ctx ctx = {

		.value    = value,

		.size     = size,

		.kname    = &kname,

		.flags    = 0,

	};



	error = import_xattr_name(&kname, name);

	if (error)

		return error;

	return filename_getxattr(AT_FDCWD, getname(pathname), lookup_flags, &ctx);

}



SYSCALL_DEFINE4(getxattr, const char __user *, pathname,

		const char __user *, name, void __user *, value, size_t, size)

{
@@ -833,13 +838,22 @@ SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname, 
SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name,

		void __user *, value, size_t, size)

{

	ssize_t error;

	struct xattr_name kname;

	struct kernel_xattr_ctx ctx = {

		.value    = value,

		.size     = size,

		.kname    = &kname,

		.flags    = 0,

	};

	CLASS(fd, f)(fd);



	if (fd_empty(f))

		return -EBADF;

	audit_file(fd_file(f));

	return getxattr(file_mnt_idmap(fd_file(f)), fd_file(f)->f_path.dentry,

			 name, value, size);

	error = import_xattr_name(&kname, name);

	if (error)

		return error;

	return file_getxattr(fd_file(f), &ctx);

}



/*

io_uring/xattr.c

+7 −24
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ static int __io_getxattr_prep(struct io_kiocb *req, 
	ix->filename = NULL;

	ix->ctx.kvalue = NULL;

	name = u64_to_user_ptr(READ_ONCE(sqe->addr));

	ix->ctx.cvalue = u64_to_user_ptr(READ_ONCE(sqe->addr2));

	ix->ctx.value = u64_to_user_ptr(READ_ONCE(sqe->addr2));

	ix->ctx.size = READ_ONCE(sqe->len);

	ix->ctx.flags = READ_ONCE(sqe->xattr_flags);
@@ -94,12 +94,10 @@ int io_getxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	path = u64_to_user_ptr(READ_ONCE(sqe->addr3));



	ix->filename = getname(path);

	if (IS_ERR(ix->filename)) {

		ret = PTR_ERR(ix->filename);

		ix->filename = NULL;

	}

	if (IS_ERR(ix->filename))

		return PTR_ERR(ix->filename);



	return ret;

	return 0;

}



int io_fgetxattr(struct io_kiocb *req, unsigned int issue_flags)
@@ -109,10 +107,7 @@ int io_fgetxattr(struct io_kiocb *req, unsigned int issue_flags) 


	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



	ret = do_getxattr(file_mnt_idmap(req->file),

			req->file->f_path.dentry,

			&ix->ctx);



	ret = file_getxattr(req->file, &ix->ctx);

	io_xattr_finish(req, ret);

	return IOU_OK;

}
@@ -120,24 +115,12 @@ int io_fgetxattr(struct io_kiocb *req, unsigned int issue_flags) 
int io_getxattr(struct io_kiocb *req, unsigned int issue_flags)

{

	struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);

	unsigned int lookup_flags = LOOKUP_FOLLOW;

	struct path path;

	int ret;



	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



retry:

	ret = filename_lookup(AT_FDCWD, ix->filename, lookup_flags, &path, NULL);

	if (!ret) {

		ret = do_getxattr(mnt_idmap(path.mnt), path.dentry, &ix->ctx);



		path_put(&path);

		if (retry_estale(ret, lookup_flags)) {

			lookup_flags |= LOOKUP_REVAL;

			goto retry;

		}

	}



	ret = filename_getxattr(AT_FDCWD, ix->filename, LOOKUP_FOLLOW, &ix->ctx);

	ix->filename = NULL;

	io_xattr_finish(req, ret);

	return IOU_OK;

}