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, 43 insertions, 0 deletions

diff --git a/include/sound/cs35l36.h b/include/sound/cs35l36.h
new file mode 100644
index 000000000..8f8049d39
--- /dev/null
+++ b/include/sound/cs35l36.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/sound/cs35l36.h -- Platform data for CS35L36
+ *
+ * Copyright 2018 Cirrus Logic, Inc.
+ *
+ * Author: James Schulman <james.schulman@cirrus.com>
+ *
+ */
+
+#ifndef __CS35L36_H
+#define __CS35L36_H
+
+struct cs35l36_vpbr_cfg {
+	bool is_present;
+	bool vpbr_en;
+	int vpbr_thld;
+	int vpbr_atk_rate;
+	int vpbr_atk_vol;
+	int vpbr_max_attn;
+	int vpbr_wait;
+	int vpbr_rel_rate;
+	int vpbr_mute_en;
+};
+
+struct cs35l36_platform_data {
+	bool multi_amp_mode;
+	bool dcm_mode;
+	bool amp_pcm_inv;
+	bool imon_pol_inv;
+	bool vmon_pol_inv;
+	int boost_ind;
+	int bst_vctl;
+	int bst_vctl_sel;
+	int bst_ipk;
+	bool extern_boost;
+	int temp_warn_thld;
+	int irq_drv_sel;
+	int irq_gpio_sel;
+	struct cs35l36_vpbr_cfg vpbr_config;
+};
+
+#endif /* __CS35L36_H */