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 --- tools/include/nolibc/assert.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 tools/include/nolibc/assert.h (limited to 'tools/include/nolibc/assert.h') diff --git a/tools/include/nolibc/assert.h b/tools/include/nolibc/assert.h new file mode 100644 index 000000000..84ff8ad9a --- /dev/null +++ b/tools/include/nolibc/assert.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ +/* + * Assert for NOLIBC + * Copyright (C) 2026 Thomas Weißschuh + */ + +/* make sure to include all global symbols */ +#include "nolibc.h" + +#ifndef _NOLIBC_ASSERT_H +#define _NOLIBC_ASSERT_H + +#include "errno.h" +#include "stdio.h" +#include "stdlib.h" + +#endif /* _NOLIBC_ASSERT_H */ + +/* NDEBUG needs to be evaluated on *each* inclusion */ +#ifdef assert +#undef assert +#endif + +#ifndef NDEBUG +#define assert(expr) \ +({ \ + if (!(expr)) { \ + fprintf(stderr, "%s: %s:%d: %s: Assertion `%s' failed.\n", \ + program_invocation_short_name, __FILE__, __LINE__, __func__, \ + #expr); \ + abort(); \ + } \ +}) +#else +#define assert(expr) ((void)0) +#endif -- cgit v1.3.1