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/net/esp.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 include/net/esp.h (limited to 'include/net/esp.h') diff --git a/include/net/esp.h b/include/net/esp.h new file mode 100644 index 000000000..322950727 --- /dev/null +++ b/include/net/esp.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NET_ESP_H +#define _NET_ESP_H + +#include + +struct ip_esp_hdr; +struct xfrm_state; + +static inline struct ip_esp_hdr *ip_esp_hdr(const struct sk_buff *skb) +{ + return (struct ip_esp_hdr *)skb_transport_header(skb); +} + +static inline void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) +{ + /* Fill padding... */ + if (tfclen) { + memset(tail, 0, tfclen); + tail += tfclen; + } + do { + int i; + for (i = 0; i < plen - 2; i++) + tail[i] = i + 1; + } while (0); + tail[plen - 2] = plen - 2; + tail[plen - 1] = proto; +} + +struct esp_info { + struct ip_esp_hdr *esph; + __be64 seqno; + int tfclen; + int tailen; + int plen; + int clen; + int len; + int nfrags; + __u8 proto; + bool inplace; +}; + +int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp); +int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp); +int esp_input_done2(struct sk_buff *skb, int err); +int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp); +int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp); +int esp6_input_done2(struct sk_buff *skb, int err); +#endif -- cgit v1.3.1