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/tee/tee_private.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 drivers/tee/tee_private.h (limited to 'drivers/tee/tee_private.h') diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h new file mode 100644 index 000000000..6bde688bf --- /dev/null +++ b/drivers/tee/tee_private.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2015-2016, Linaro Limited + */ +#ifndef TEE_PRIVATE_H +#define TEE_PRIVATE_H + +#include +#include +#include +#include +#include +#include +#include + +/* extra references appended to shm object for registered shared memory */ +struct tee_shm_dmabuf_ref { + struct tee_shm shm; + size_t offset; + struct dma_buf *dmabuf; + struct tee_shm *parent_shm; +}; + +int tee_shm_get_fd(struct tee_shm *shm); + +struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size); +struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx, + unsigned long addr, size_t length); + +int tee_heap_update_from_dma_buf(struct tee_device *teedev, + struct dma_buf *dmabuf, size_t *offset, + struct tee_shm *shm, + struct tee_shm **parent_shm); + +#endif /*TEE_PRIVATE_H*/ -- cgit v1.3.1