From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read 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 Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- drivers/cdx/cdx.h | 94 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 drivers/cdx/cdx.h (limited to 'drivers/cdx/cdx.h') diff --git a/drivers/cdx/cdx.h b/drivers/cdx/cdx.h new file mode 100644 index 000000000..9c60c04dc --- /dev/null +++ b/drivers/cdx/cdx.h @@ -0,0 +1,94 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * Header file for the CDX Bus + * + * Copyright (C) 2022-2023, Advanced Micro Devices, Inc. + */ + +#ifndef _CDX_H_ +#define _CDX_H_ + +#include + +/** + * struct cdx_dev_params - CDX device parameters + * @cdx: CDX controller associated with the device + * @parent: Associated CDX Bus device + * @vendor: Vendor ID for CDX device + * @device: Device ID for CDX device + * @subsys_vendor: Sub vendor ID for CDX device + * @subsys_device: Sub device ID for CDX device + * @bus_num: Bus number for this CDX device + * @dev_num: Device number for this device + * @res: array of MMIO region entries + * @res_count: number of valid MMIO regions + * @req_id: Requestor ID associated with CDX device + * @class: Class of the CDX Device + * @revision: Revision of the CDX device + * @msi_dev_id: MSI device ID associated with CDX device + * @num_msi: Number of MSI's supported by the device + */ +struct cdx_dev_params { + struct cdx_controller *cdx; + struct device *parent; + u16 vendor; + u16 device; + u16 subsys_vendor; + u16 subsys_device; + u8 bus_num; + u8 dev_num; + struct resource res[MAX_CDX_DEV_RESOURCES]; + u8 res_count; + u32 req_id; + u32 class; + u8 revision; + u32 msi_dev_id; + u32 num_msi; +}; + +/** + * cdx_register_controller - Register a CDX controller and its ports + * on the CDX bus. + * @cdx: The CDX controller to register + * + * Return: -errno on failure, 0 on success. + */ +int cdx_register_controller(struct cdx_controller *cdx); + +/** + * cdx_unregister_controller - Unregister a CDX controller + * @cdx: The CDX controller to unregister + */ +void cdx_unregister_controller(struct cdx_controller *cdx); + +/** + * cdx_device_add - Add a CDX device. This function adds a CDX device + * on the CDX bus as per the device parameters provided + * by caller. It also creates and registers an associated + * Linux generic device. + * @dev_params: device parameters associated with the device to be created. + * + * Return: -errno on failure, 0 on success. + */ +int cdx_device_add(struct cdx_dev_params *dev_params); + +/** + * cdx_bus_add - Add a CDX bus. This function adds a bus on the CDX bus + * subsystem. It creates a CDX device for the corresponding bus and + * also registers an associated Linux generic device. + * @cdx: Associated CDX controller + * @us_num: Bus number + * + * Return: associated Linux generic device pointer on success or NULL on failure. + */ +struct device *cdx_bus_add(struct cdx_controller *cdx, u8 bus_num); + +/** + * cdx_msi_domain_init - Init the CDX bus MSI domain. + * @dev: Device of the CDX bus controller + * + * Return: CDX MSI domain, NULL on failure + */ +struct irq_domain *cdx_msi_domain_init(struct device *dev); + +#endif /* _CDX_H_ */ -- cgit v1.3.1