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/testing/shared/shared.mk | 79 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 tools/testing/shared/shared.mk (limited to 'tools/testing/shared/shared.mk') diff --git a/tools/testing/shared/shared.mk b/tools/testing/shared/shared.mk new file mode 100644 index 000000000..5bcdf26c8 --- /dev/null +++ b/tools/testing/shared/shared.mk @@ -0,0 +1,79 @@ +# SPDX-License-Identifier: GPL-2.0 +include ../../scripts/Makefile.arch + +CFLAGS += -I../shared -I. -I../../include -I../../arch/$(SRCARCH)/include \ + -I../../../lib -g -Og -Wall \ + -D_LGPL_SOURCE -fsanitize=address -fsanitize=undefined +CFLAGS += $(EXTRA_CFLAGS) +LDFLAGS += -fsanitize=address -fsanitize=undefined +LDLIBS += -lpthread -lurcu +LIBS := slab.o find_bit.o bitmap.o hweight.o vsprintf.o +SHARED_OFILES = xarray-shared.o radix-tree.o idr.o linux.o $(LIBS) + +SHARED_DEPS = Makefile ../shared/shared.mk ../shared/*.h generated/map-shift.h \ + generated/bit-length.h generated/autoconf.h \ + ../../include/linux/*.h \ + ../../include/asm/*.h \ + ../../arch/$(SRCARCH)/include/asm/*.h \ + ../../../include/linux/xarray.h \ + ../../../include/linux/maple_tree.h \ + ../../../include/linux/radix-tree.h \ + ../../../lib/radix-tree.h \ + ../../../include/linux/idr.h \ + ../../../lib/maple_tree.c \ + ../../../lib/test_maple_tree.c + +ifndef SHIFT + SHIFT=3 +endif + +ifeq ($(BUILD), 32) + CFLAGS += -m32 + LDFLAGS += -m32 +LONG_BIT := 32 +endif + +ifndef LONG_BIT +LONG_BIT := $(shell getconf LONG_BIT) +endif + +%.o: ../shared/%.c + $(CC) -c $(CFLAGS) $< -o $@ + +vpath %.c ../../lib + +$(SHARED_OFILES): $(SHARED_DEPS) + +radix-tree.c: ../../../lib/radix-tree.c + sed -e 's/^static //' -e 's/__always_inline //' -e 's/inline //' < $< > $@ + +idr.c: ../../../lib/idr.c + sed -e 's/^static //' -e 's/__always_inline //' -e 's/inline //' < $< > $@ + +xarray-shared.o: ../shared/xarray-shared.c ../../../lib/xarray.c \ + ../../../lib/test_xarray.c + +maple-shared.o: ../shared/maple-shared.c ../../../lib/maple_tree.c \ + ../../../lib/test_maple_tree.c + +generated/autoconf.h: + @mkdir -p generated + cp ../shared/autoconf.h generated/autoconf.h + +generated/map-shift.h: + @mkdir -p generated + @if ! grep -qws $(SHIFT) generated/map-shift.h; then \ + echo "Generating $@"; \ + echo "#define XA_CHUNK_SHIFT $(SHIFT)" > \ + generated/map-shift.h; \ + fi + +generated/bit-length.h: FORCE + @mkdir -p generated + @if ! grep -qws CONFIG_$(LONG_BIT)BIT generated/bit-length.h; then \ + echo "Generating $@"; \ + echo "#define CONFIG_$(LONG_BIT)BIT 1" > $@; \ + echo "#define CONFIG_PHYS_ADDR_T_$(LONG_BIT)BIT 1" >> $@; \ + fi + +FORCE: ; -- cgit v1.3.1