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/firmware/imx/rm.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 drivers/firmware/imx/rm.c (limited to 'drivers/firmware/imx/rm.c') diff --git a/drivers/firmware/imx/rm.c b/drivers/firmware/imx/rm.c new file mode 100644 index 000000000..d492b99e1 --- /dev/null +++ b/drivers/firmware/imx/rm.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2020 NXP + * + * File containing client-side RPC functions for the RM service. These + * function are ported to clients that communicate to the SC. + */ + +#include + +struct imx_sc_msg_rm_rsrc_owned { + struct imx_sc_rpc_msg hdr; + u16 resource; +} __packed __aligned(4); + +/* + * This function check @resource is owned by current partition or not + * + * @param[in] ipc IPC handle + * @param[in] resource resource the control is associated with + * + * @return Returns 0 for not owned and 1 for owned. + */ +bool imx_sc_rm_is_resource_owned(struct imx_sc_ipc *ipc, u16 resource) +{ + struct imx_sc_msg_rm_rsrc_owned msg; + struct imx_sc_rpc_msg *hdr = &msg.hdr; + + hdr->ver = IMX_SC_RPC_VERSION; + hdr->svc = IMX_SC_RPC_SVC_RM; + hdr->func = IMX_SC_RM_FUNC_IS_RESOURCE_OWNED; + hdr->size = 2; + + msg.resource = resource; + + /* + * SCU firmware only returns value 0 or 1 + * for resource owned check which means not owned or owned. + * So it is always successful. + */ + imx_scu_call_rpc(ipc, &msg, true); + + return hdr->func; +} +EXPORT_SYMBOL(imx_sc_rm_is_resource_owned); + +struct imx_sc_msg_rm_get_resource_owner { + struct imx_sc_rpc_msg hdr; + union { + struct { + u16 resource; + } req; + struct { + u8 val; + } resp; + } data; +} __packed __aligned(4); + +/* + * This function get @resource partition number + * + * @param[in] ipc IPC handle + * @param[in] resource resource the control is associated with + * @param[out] pt pointer to return the partition number + * + * @return Returns 0 for success and < 0 for errors. + */ +int imx_sc_rm_get_resource_owner(struct imx_sc_ipc *ipc, u16 resource, u8 *pt) +{ + struct imx_sc_msg_rm_get_resource_owner msg; + struct imx_sc_rpc_msg *hdr = &msg.hdr; + int ret; + + hdr->ver = IMX_SC_RPC_VERSION; + hdr->svc = IMX_SC_RPC_SVC_RM; + hdr->func = IMX_SC_RM_FUNC_GET_RESOURCE_OWNER; + hdr->size = 2; + + msg.data.req.resource = resource; + + ret = imx_scu_call_rpc(ipc, &msg, true); + if (ret) + return ret; + + if (pt) + *pt = msg.data.resp.val; + + return 0; +} +EXPORT_SYMBOL(imx_sc_rm_get_resource_owner); -- cgit v1.3.1