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 --- include/uapi/fwctl/pds.h | 62 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 include/uapi/fwctl/pds.h (limited to 'include/uapi/fwctl/pds.h') diff --git a/include/uapi/fwctl/pds.h b/include/uapi/fwctl/pds.h new file mode 100644 index 000000000..66be32411 --- /dev/null +++ b/include/uapi/fwctl/pds.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* Copyright(c) Advanced Micro Devices, Inc */ + +/* + * fwctl interface info for pds_fwctl + */ + +#ifndef _UAPI_FWCTL_PDS_H_ +#define _UAPI_FWCTL_PDS_H_ + +#include + +/** + * struct fwctl_info_pds + * @uctx_caps: bitmap of firmware capabilities + * + * Return basic information about the FW interface available. + */ +struct fwctl_info_pds { + __u32 uctx_caps; +}; + +/** + * enum pds_fwctl_capabilities + * @PDS_FWCTL_QUERY_CAP: firmware can be queried for information + * @PDS_FWCTL_SEND_CAP: firmware can be sent commands + */ +enum pds_fwctl_capabilities { + PDS_FWCTL_QUERY_CAP = 0, + PDS_FWCTL_SEND_CAP, +}; + +/** + * struct fwctl_rpc_pds + * @in.op: requested operation code + * @in.ep: firmware endpoint to operate on + * @in.rsvd: reserved + * @in.len: length of payload data + * @in.payload: address of payload buffer + * @in: rpc in parameters + * @out.retval: operation result value + * @out.rsvd: reserved + * @out.len: length of result data buffer + * @out.payload: address of payload data buffer + * @out: rpc out parameters + */ +struct fwctl_rpc_pds { + struct { + __u32 op; + __u32 ep; + __u32 rsvd; + __u32 len; + __aligned_u64 payload; + } in; + struct { + __u32 retval; + __u32 rsvd[2]; + __u32 len; + __aligned_u64 payload; + } out; +}; +#endif /* _UAPI_FWCTL_PDS_H_ */ -- cgit v1.3.1