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 --- scripts/Makefile.debug | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 scripts/Makefile.debug (limited to 'scripts/Makefile.debug') diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug new file mode 100644 index 000000000..107db997c --- /dev/null +++ b/scripts/Makefile.debug @@ -0,0 +1,52 @@ +DEBUG_CFLAGS := +DEBUG_RUSTFLAGS := + +debug-flags-y := -g + +ifdef CONFIG_DEBUG_INFO_SPLIT +DEBUG_CFLAGS += -gsplit-dwarf +endif + +debug-flags-$(CONFIG_DEBUG_INFO_DWARF4) += -gdwarf-4 +debug-flags-$(CONFIG_DEBUG_INFO_DWARF5) += -gdwarf-5 +ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_AS_IS_GNU),yy) +# Clang does not pass -g or -gdwarf-* option down to GAS. +# Add -Wa, prefix to explicitly specify the flags. +KBUILD_AFLAGS += $(addprefix -Wa$(comma), $(debug-flags-y)) +endif +DEBUG_CFLAGS += $(debug-flags-y) +KBUILD_AFLAGS += $(debug-flags-y) + +ifdef CONFIG_DEBUG_INFO_DWARF4 +DEBUG_RUSTFLAGS += -Zdwarf-version=4 +else ifdef CONFIG_DEBUG_INFO_DWARF5 +DEBUG_RUSTFLAGS += -Zdwarf-version=5 +endif + +ifdef CONFIG_DEBUG_INFO_REDUCED +DEBUG_CFLAGS += -fno-var-tracking +DEBUG_RUSTFLAGS += -Cdebuginfo=1 +ifdef CONFIG_CC_IS_GCC +DEBUG_CFLAGS += -femit-struct-debug-baseonly +endif +else +DEBUG_RUSTFLAGS += -Cdebuginfo=2 +endif + +ifdef CONFIG_DEBUG_INFO_COMPRESSED_ZLIB +DEBUG_CFLAGS += -gz=zlib +DEBUG_RUSTFLAGS += -Zdebuginfo-compression=zlib +KBUILD_AFLAGS += -gz=zlib +KBUILD_LDFLAGS += --compress-debug-sections=zlib +else ifdef CONFIG_DEBUG_INFO_COMPRESSED_ZSTD +DEBUG_CFLAGS += -gz=zstd +DEBUG_RUSTFLAGS += -Zdebuginfo-compression=zstd +KBUILD_AFLAGS += -gz=zstd +KBUILD_LDFLAGS += --compress-debug-sections=zstd +endif + +KBUILD_CFLAGS += $(DEBUG_CFLAGS) +export DEBUG_CFLAGS + +KBUILD_RUSTFLAGS += $(DEBUG_RUSTFLAGS) +export DEBUG_RUSTFLAGS -- cgit v1.3.1