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, 129 insertions, 0 deletions

diff --git a/drivers/net/phy/bcm-phy-lib.h b/drivers/net/phy/bcm-phy-lib.h
new file mode 100644
index 000000000..bba94ce96
--- /dev/null
+++ b/drivers/net/phy/bcm-phy-lib.h
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2015 Broadcom Corporation
+ */
+
+#ifndef _LINUX_BCM_PHY_LIB_H
+#define _LINUX_BCM_PHY_LIB_H
+
+#include <linux/brcmphy.h>
+#include <linux/phy.h>
+#include <linux/interrupt.h>
+
+struct ethtool_wolinfo;
+
+/* 28nm only register definitions */
+#define MISC_ADDR(base, channel)	base, channel
+
+#define DSP_TAP10			MISC_ADDR(0x0a, 0)
+#define PLL_PLLCTRL_1			MISC_ADDR(0x32, 1)
+#define PLL_PLLCTRL_2			MISC_ADDR(0x32, 2)
+#define PLL_PLLCTRL_4			MISC_ADDR(0x33, 0)
+
+#define AFE_RXCONFIG_0			MISC_ADDR(0x38, 0)
+#define AFE_RXCONFIG_1			MISC_ADDR(0x38, 1)
+#define AFE_RXCONFIG_2			MISC_ADDR(0x38, 2)
+#define AFE_RX_LP_COUNTER		MISC_ADDR(0x38, 3)
+#define AFE_TX_CONFIG			MISC_ADDR(0x39, 0)
+#define AFE_VDCA_ICTRL_0		MISC_ADDR(0x39, 1)
+#define AFE_VDAC_OTHERS_0		MISC_ADDR(0x39, 3)
+#define AFE_HPF_TRIM_OTHERS		MISC_ADDR(0x3a, 0)
+
+
+int __bcm_phy_write_exp(struct phy_device *phydev, u16 reg, u16 val);
+int __bcm_phy_read_exp(struct phy_device *phydev, u16 reg);
+int __bcm_phy_modify_exp(struct phy_device *phydev, u16 reg, u16 mask, u16 set);
+int bcm_phy_write_exp(struct phy_device *phydev, u16 reg, u16 val);
+int bcm_phy_read_exp(struct phy_device *phydev, u16 reg);
+int bcm_phy_modify_exp(struct phy_device *phydev, u16 reg, u16 mask, u16 set);
+
+static inline int bcm_phy_write_exp_sel(struct phy_device *phydev,
+					u16 reg, u16 val)
+{
+	return bcm_phy_write_exp(phydev, reg | MII_BCM54XX_EXP_SEL_ER, val);
+}
+
+static inline int bcm_phy_read_exp_sel(struct phy_device *phydev, u16 reg)
+{
+	return bcm_phy_read_exp(phydev, reg | MII_BCM54XX_EXP_SEL_ER);
+}
+
+int bcm54xx_auxctl_write(struct phy_device *phydev, u16 regnum, u16 val);
+int bcm54xx_auxctl_read(struct phy_device *phydev, u16 regnum);
+
+int bcm_phy_write_misc(struct phy_device *phydev,
+		       u16 reg, u16 chl, u16 value);
+int bcm_phy_read_misc(struct phy_device *phydev,
+		      u16 reg, u16 chl);
+
+int bcm_phy_write_shadow(struct phy_device *phydev, u16 shadow,
+			 u16 val);
+int bcm_phy_read_shadow(struct phy_device *phydev, u16 shadow);
+
+int __bcm_phy_write_rdb(struct phy_device *phydev, u16 rdb, u16 val);
+int bcm_phy_write_rdb(struct phy_device *phydev, u16 rdb, u16 val);
+int __bcm_phy_read_rdb(struct phy_device *phydev, u16 rdb);
+int bcm_phy_read_rdb(struct phy_device *phydev, u16 rdb);
+int __bcm_phy_modify_rdb(struct phy_device *phydev, u16 rdb, u16 mask,
+			 u16 set);
+int bcm_phy_modify_rdb(struct phy_device *phydev, u16 rdb, u16 mask,
+		       u16 set);
+
+int bcm_phy_ack_intr(struct phy_device *phydev);
+int bcm_phy_config_intr(struct phy_device *phydev);
+irqreturn_t bcm_phy_handle_interrupt(struct phy_device *phydev);
+
+int bcm_phy_enable_apd(struct phy_device *phydev, bool dll_pwr_down);
+
+int bcm_phy_set_eee(struct phy_device *phydev, bool enable);
+
+int bcm_phy_downshift_get(struct phy_device *phydev, u8 *count);
+
+int bcm_phy_downshift_set(struct phy_device *phydev, u8 count);
+
+int bcm_phy_get_sset_count(struct phy_device *phydev);
+void bcm_phy_get_strings(struct phy_device *phydev, u8 *data);
+void bcm_phy_get_stats(struct phy_device *phydev, u64 *shadow,
+		       struct ethtool_stats *stats, u64 *data);
+void bcm_phy_update_stats_shadow(struct phy_device *phydev, u64 *shadow);
+void bcm_phy_r_rc_cal_reset(struct phy_device *phydev);
+int bcm_phy_28nm_a0b0_afe_config_init(struct phy_device *phydev);
+int bcm_phy_enable_jumbo(struct phy_device *phydev);
+
+int bcm_phy_cable_test_get_status_rdb(struct phy_device *phydev,
+				      bool *finished);
+int bcm_phy_cable_test_start_rdb(struct phy_device *phydev);
+int bcm_phy_cable_test_start(struct phy_device *phydev);
+int bcm_phy_cable_test_get_status(struct phy_device *phydev, bool *finished);
+
+#if IS_ENABLED(CONFIG_BCM_NET_PHYPTP)
+struct bcm_ptp_private *bcm_ptp_probe(struct phy_device *phydev);
+void bcm_ptp_config_init(struct phy_device *phydev);
+void bcm_ptp_stop(struct bcm_ptp_private *priv);
+#else
+static inline struct bcm_ptp_private *bcm_ptp_probe(struct phy_device *phydev)
+{
+	return NULL;
+}
+
+static inline void bcm_ptp_config_init(struct phy_device *phydev)
+{
+}
+
+static inline void bcm_ptp_stop(struct bcm_ptp_private *priv)
+{
+}
+#endif
+
+int bcm_phy_set_wol(struct phy_device *phydev, struct ethtool_wolinfo *wol);
+void bcm_phy_get_wol(struct phy_device *phydev, struct ethtool_wolinfo *wol);
+irqreturn_t bcm_phy_wol_isr(int irq, void *dev_id);
+
+int bcm_phy_led_brightness_set(struct phy_device *phydev,
+			       u8 index, enum led_brightness value);
+
+int bcm_setup_lre_master_slave(struct phy_device *phydev);
+int bcm_config_lre_aneg(struct phy_device *phydev, bool changed);
+int bcm_config_lre_advert(struct phy_device *phydev);
+
+#endif /* _LINUX_BCM_PHY_LIB_H */