ext4: allow readdir()'s of large empty directories to be interrupted

If a directory has a large number of empty blocks, iterating over all
of them can take a long time, leading to scheduler warnings and users
getting irritated when they can't kill a process in the middle of one
of these long-running readdir operations.  Fix this by adding checks to
ext4_readdir() and ext4_htree_fill_tree().

This was reverted earlier due to a typo in the original commit where I
experimented with using signal_pending() instead of
fatal_signal_pending().  The test was in the wrong place if we were
going to return signal_pending() since we would end up returning
duplicant entries.  See 9f2394c9be47 for a more detailed explanation.

Added fix as suggested by Linus to check for signal_pending() in
in the filldir() functions.

Reported-by: Benjamin LaHaise <bcrl@kvack.org>
Google-Bug-Id: 27880676
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

path: root/bpfc/Makefile

bpfc-libs =

bpfc-objs =	xmalloc.o \
		str.o \
		bpf.o \
		bpf_lexer.yy.o \
		bpf_parser.tab.o \
		bpfc.o

bpfc-lex =	bpf_lexer.yy.o

bpfc-yaac =	bpf_parser.tab.o

bpfc-eflags =	-I..

bpfc-confs =

bpfc_clean_custom:
	$(Q)$(call RM,$(BUILD_DIR)/*.h $(BUILD_DIR)/*.c)