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/usb/image/microtek.h | 55 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 drivers/usb/image/microtek.h (limited to 'drivers/usb/image/microtek.h') diff --git a/drivers/usb/image/microtek.h b/drivers/usb/image/microtek.h new file mode 100644 index 000000000..7bd5f4639 --- /dev/null +++ b/drivers/usb/image/microtek.h @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + /* + * Driver for Microtek Scanmaker X6 USB scanner and possibly others. + * + * (C) Copyright 2000 John Fremlin + * (C) Copyright 2000 Oliver Neukum + * + * See microtek.c for history + * + */ + +typedef void (*mts_scsi_cmnd_callback)(struct scsi_cmnd *); + + +struct mts_transfer_context +{ + struct mts_desc *instance; + mts_scsi_cmnd_callback final_callback; + struct scsi_cmnd *srb; + + void *data; + unsigned data_length; + int data_pipe; + struct scatterlist *curr_sg; + + u8 *scsi_status; /* status returned from ep_response after command completion */ +}; + + +struct mts_desc { + struct mts_desc *next; + struct mts_desc *prev; + + struct usb_device *usb_dev; + struct usb_interface *usb_intf; + + /* Endpoint addresses */ + u8 ep_out; + u8 ep_response; + u8 ep_image; + + struct Scsi_Host *host; + + struct urb *urb; + struct mts_transfer_context context; +}; + + +#define MTS_EP_OUT 0x1 +#define MTS_EP_RESPONSE 0x2 +#define MTS_EP_IMAGE 0x3 +#define MTS_EP_TOTAL 0x3 + +#define MTS_SCSI_ERR_MASK ~0x3fu + -- cgit v1.3.1