From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22296C7EE2F for ; Fri, 9 Jun 2023 06:54:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238128AbjFIGyI (ORCPT ); Fri, 9 Jun 2023 02:54:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230097AbjFIGyH (ORCPT ); Fri, 9 Jun 2023 02:54:07 -0400 Received: from aer-iport-7.cisco.com (aer-iport-7.cisco.com [173.38.203.69]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A863626AD for ; Thu, 8 Jun 2023 23:54:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=2817; q=dns/txt; s=iport; t=1686293645; x=1687503245; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=UU0E2+JcdWBDuifFC8J0oRKTGuH0HZrRR0fIeys5Q4I=; b=VpB3a6TTOIb9liL48mp2eYNrbflpY0+fIf1i/8p3mQqnntmy6+YS3TNK 0UMydNtl/FSI/5oNm4eVdXGZep9sCHZKJkLySgbdE4SaAh87MYCgEOQNg 49r3rLcyx0eIiq456Rb/5SeVlUyOBd5JBBd68hYooymcxGdSrecQvU5ru c=; X-IronPort-AV: E=Sophos;i="6.00,228,1681171200"; d="scan'208";a="8508933" Received: from aer-iport-nat.cisco.com (HELO aer-core-5.cisco.com) ([173.38.203.22]) by aer-iport-7.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 09 Jun 2023 06:31:54 +0000 Received: from archlinux-cisco.cisco.com ([10.61.198.236]) (authenticated bits=0) by aer-core-5.cisco.com (8.15.2/8.15.2) with ESMTPSA id 3596VIDo055061 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 9 Jun 2023 06:31:54 GMT From: Ariel Miculas To: rust-for-linux@vger.kernel.org Cc: Ariel Miculas Subject: [PATCH 56/80] rust: file: add methods read_to_end, get_file_size and update_pos to RegularFile Date: Fri, 9 Jun 2023 09:30:54 +0300 Message-Id: <20230609063118.24852-57-amiculas@cisco.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230609063118.24852-1-amiculas@cisco.com> References: <20230609063118.24852-1-amiculas@cisco.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Authenticated-User: amiculas X-Outbound-SMTP-Client: 10.61.198.236, [10.61.198.236] X-Outbound-Node: aer-core-5.cisco.com Precedence: bulk List-ID: X-Mailing-List: rust-for-linux@vger.kernel.org Signed-off-by: Ariel Miculas --- rust/kernel/file.rs | 52 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/rust/kernel/file.rs b/rust/kernel/file.rs index 5b119d6c4f72..894ee573d147 100644 --- a/rust/kernel/file.rs +++ b/rust/kernel/file.rs @@ -22,6 +22,7 @@ types::Opaque, user_ptr::{UserSlicePtr, UserSlicePtrReader, UserSlicePtrWriter}, }; +use alloc::vec::Vec; use core::convert::{TryFrom, TryInto}; use core::{marker, mem, ptr}; use macros::vtable; @@ -288,10 +289,61 @@ pub fn read_with_offset(&self, buf: &mut [u8], offset: u64) -> Result { }) } + /// Allocate and return a vector containing the contents of the entire file + pub fn read_to_end(&self) -> Result> { + let file_size = self.get_file_size()?; + let mut buffer = Vec::try_with_capacity(file_size)?; + buffer.try_resize(file_size, 0)?; + self.read_with_offset(&mut buffer, 0)?; + Ok(buffer) + } + /// Get the current file position pub fn get_pos(&self) -> u64 { self.0.pos() } + + fn get_file_size(&self) -> Result { + let mut buf = Vec::new(); + unsafe { + // kernel_read_file expects a pointer to a "void *" buffer + let mut ptr_to_buf = buf.as_mut_ptr() as *mut core::ffi::c_void; + let mut file_size = 0; + + // SAFETY: all the pointers to kernel_read_file are valid + let result = bindings::kernel_read_file( + self.0 .0.get(), + 0, + &mut ptr_to_buf, + buf.len(), + &mut file_size, + bindings::kernel_read_file_id_READING_UNKNOWN, + ); + + // kernel_read_file returns the number of bytes read on success or negative on error. + if result < 0 { + return Err(Error::from_errno(result.try_into()?)); + } + Ok(file_size) + } + } + + fn update_pos(&self, where_to: SeekFrom) -> Result { + let (offset, whence): (i64, _) = match where_to { + SeekFrom::Start(off) => (off.try_into()?, bindings::SEEK_SET), + SeekFrom::Current(off) => (off, bindings::SEEK_CUR), + SeekFrom::End(off) => (off, bindings::SEEK_END), + }; + + let offset = + unsafe { bindings::generic_file_llseek(self.0 .0.get(), offset, whence.try_into()?) }; + if offset < 0 { + return Err(Error::from_errno(offset.try_into()?)); + } + + // we just checked that offset is non negative + Ok(offset as u64) + } } /// A file descriptor reservation. -- 2.40.1