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/geneve.h | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 include/net/geneve.h (limited to 'include/net/geneve.h') diff --git a/include/net/geneve.h b/include/net/geneve.h new file mode 100644 index 000000000..ba2c14d61 --- /dev/null +++ b/include/net/geneve.h @@ -0,0 +1,71 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_GENEVE_H +#define __NET_GENEVE_H 1 + +#include + +#define GENEVE_UDP_PORT 6081 + +/* Geneve Header: + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |Ver| Opt Len |O|C| Rsvd. | Protocol Type | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Virtual Network Identifier (VNI) | Reserved | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Variable Length Options | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * Option Header: + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Option Class | Type |R|R|R| Length | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Variable Option Data | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + +struct geneve_opt { + __be16 opt_class; + u8 type; +#ifdef __LITTLE_ENDIAN_BITFIELD + u8 length:5; + u8 r3:1; + u8 r2:1; + u8 r1:1; +#else + u8 r1:1; + u8 r2:1; + u8 r3:1; + u8 length:5; +#endif + u8 opt_data[]; +}; + +#define GENEVE_CRIT_OPT_TYPE (1 << 7) + +struct genevehdr { +#ifdef __LITTLE_ENDIAN_BITFIELD + u8 opt_len:6; + u8 ver:2; + u8 rsvd1:6; + u8 critical:1; + u8 oam:1; +#else + u8 ver:2; + u8 opt_len:6; + u8 oam:1; + u8 critical:1; + u8 rsvd1:6; +#endif + __be16 proto_type; + u8 vni[3]; + u8 rsvd2; + u8 options[]; +}; + +static inline bool netif_is_geneve(const struct net_device *dev) +{ + return dev->rtnl_link_ops && + !strcmp(dev->rtnl_link_ops->kind, "geneve"); +} + +#endif /*ifdef__NET_GENEVE_H */ -- cgit v1.3.1