netfs: zero the tail of a short DIO/unbuffered readgrafted

The buffered read collector zero-fills the tail of a short read that
stops below the inode's i_size (netfs_clear_unread()), so a read that
races an extending write still returns the expected number of bytes.
The non-buffered collector path does no such thing: it just records
how much was transferred.

Add the same zero-fill for the non-buffered case, gated on
NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short
result from it is known to be safe to treat as a hole, as opposed to
NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of
the file and should be reported short as-is. Only CLEAR_TAIL should
zero-fill here; a real EOF must stay a real short read.

No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest,
so this is inert on its own -- a following change teaches cifs to set
it in the one case that needs it.

Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item")
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Shyam Prasad N <sprasad@microsoft.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Bharath SM <bharathsm@microsoft.com>
Cc: stable@vger.kernel.org

1 files changed, 144 insertions, 0 deletions

diff --git a/include/sound/sof/info.h b/include/sound/sof/info.h
new file mode 100644
index 000000000..08400fbe5
--- /dev/null
+++ b/include/sound/sof/info.h
@@ -0,0 +1,144 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Copyright(c) 2018 Intel Corporation
+ */
+
+#ifndef __INCLUDE_SOUND_SOF_INFO_H__
+#define __INCLUDE_SOUND_SOF_INFO_H__
+
+#include <sound/sof/header.h>
+#include <sound/sof/stream.h>
+
+/*
+ * Firmware boot and version
+ */
+
+#define SOF_IPC_MAX_ELEMS	16
+
+/*
+ * Firmware boot info flag bits (64-bit)
+ */
+#define SOF_IPC_INFO_BUILD		BIT(0)
+#define SOF_IPC_INFO_LOCKS		BIT(1)
+#define SOF_IPC_INFO_LOCKSV		BIT(2)
+#define SOF_IPC_INFO_GDB		BIT(3)
+#define SOF_IPC_INFO_D3_PERSISTENT	BIT(4)
+
+/* extended data types that can be appended onto end of sof_ipc_fw_ready */
+enum sof_ipc_ext_data {
+	SOF_IPC_EXT_UNUSED		= 0,
+	SOF_IPC_EXT_WINDOW		= 1,
+	SOF_IPC_EXT_CC_INFO		= 2,
+	SOF_IPC_EXT_PROBE_INFO		= 3,
+	SOF_IPC_EXT_USER_ABI_INFO	= 4,
+};
+
+/* Build u32 number in format MMmmmppp */
+#define SOF_FW_VER(MAJOR, MINOR, PATCH) ((uint32_t)( \
+	((MAJOR) << 24) | ((MINOR) << 12) | (PATCH)))
+
+/* FW version - SOF_IPC_GLB_VERSION */
+struct sof_ipc_fw_version {
+	struct sof_ipc_hdr hdr;
+	uint16_t major;
+	uint16_t minor;
+	uint16_t micro;
+	uint16_t build;
+	uint8_t date[12];
+	uint8_t time[10];
+	uint8_t tag[6];
+	uint32_t abi_version;
+	/* used to check FW and ldc file compatibility, reproducible value */
+	uint32_t src_hash;
+
+	/* reserved for future use */
+	uint32_t reserved[3];
+} __packed;
+
+/* FW ready Message - sent by firmware when boot has completed */
+struct sof_ipc_fw_ready {
+	struct sof_ipc_cmd_hdr hdr;
+	uint32_t dspbox_offset;	 /* dsp initiated IPC mailbox */
+	uint32_t hostbox_offset; /* host initiated IPC mailbox */
+	uint32_t dspbox_size;
+	uint32_t hostbox_size;
+	struct sof_ipc_fw_version version;
+
+	/* Miscellaneous flags */
+	uint64_t flags;
+
+	/* reserved for future use */
+	uint32_t reserved[4];
+} __packed;
+
+/*
+ * Extended Firmware data. All optional, depends on platform/arch.
+ */
+enum sof_ipc_region {
+	SOF_IPC_REGION_DOWNBOX	= 0,
+	SOF_IPC_REGION_UPBOX,
+	SOF_IPC_REGION_TRACE,
+	SOF_IPC_REGION_DEBUG,
+	SOF_IPC_REGION_STREAM,
+	SOF_IPC_REGION_REGS,
+	SOF_IPC_REGION_EXCEPTION,
+};
+
+struct sof_ipc_ext_data_hdr {
+	struct sof_ipc_cmd_hdr hdr;
+	uint32_t type;		/**< SOF_IPC_EXT_ */
+} __packed;
+
+struct sof_ipc_window_elem {
+	struct sof_ipc_hdr hdr;
+	uint32_t type;		/**< SOF_IPC_REGION_ */
+	uint32_t id;		/**< platform specific - used to map to host memory */
+	uint32_t flags;		/**< R, W, RW, etc - to define */
+	uint32_t size;		/**< size of region in bytes */
+	/* offset in window region as windows can be partitioned */
+	uint32_t offset;
+} __packed;
+
+/* extended data memory windows for IPC, trace and debug */
+struct sof_ipc_window {
+	struct sof_ipc_ext_data_hdr ext_hdr;
+	uint32_t num_windows;
+	struct sof_ipc_window_elem window[SOF_IPC_MAX_ELEMS];
+}  __packed;
+
+struct sof_ipc_cc_version {
+	struct sof_ipc_ext_data_hdr ext_hdr;
+	uint32_t major;
+	uint32_t minor;
+	uint32_t micro;
+
+	/* reserved for future use */
+	uint32_t reserved[4];
+
+	uint8_t name[16]; /* null terminated compiler name */
+	uint8_t optim[4]; /* null terminated compiler -O flag value */
+	uint8_t desc[32]; /* null terminated compiler description */
+} __packed;
+
+/* extended data: Probe setup */
+struct sof_ipc_probe_support {
+	struct sof_ipc_ext_data_hdr ext_hdr;
+
+	uint32_t probe_points_max;
+	uint32_t injection_dmas_max;
+
+	/* reserved for future use */
+	uint32_t reserved[2];
+} __packed;
+
+/* extended data: user abi version(s) */
+struct sof_ipc_user_abi_version {
+	struct sof_ipc_ext_data_hdr ext_hdr;
+
+	uint32_t abi_dbg_version;
+}  __packed;
+
+#endif