Add flag to forcibly disable fallocate

Summary:
see https://github.com/facebook/rocksdb/issues/977; there are issues
with fallocate() on certain filesystems/kernel versions that can lead it to pre-
allocating blocks but never freeing them, even if they're unused.

Test Plan:
verified build commands omit DROCKSDB_FALLOCATE_PRESENT when this env
variable is set.

without disabling it:

  $ ROCKSDB_NO_FBCODE=1 make -n env_test | grep -q DROCKSDB_FALLOCATE_PRESENT ; echo $?
  0

with disabling it:

  $ ROCKSDB_NO_FBCODE=1 DISABLE_FALLOCATE=1 make -n env_test | grep -q DROCKSDB_FALLOCATE_PRESENT ; echo $?
  1

Reviewers: kradhakrishnan, yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D54069
This commit is contained in:
Andrew Kryczka 2016-02-11 17:00:01 -08:00
parent 92a9ccf1a6
commit 6a2b4fcb80

View File

@ -189,17 +189,19 @@ if [ "$CROSS_COMPILE" = "true" -o "$FBCODE_BUILD" = "true" ]; then
# Also don't need any compilation tests if compiling on fbcode
true
else
# Test whether fallocate is available
$CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null <<EOF
#include <fcntl.h>
#include <linux/falloc.h>
int main() {
int fd = open("/dev/null", 0);
fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, 0, 1024);
}
if ! test $ROCKSDB_DISABLE_FALLOCATE; then
# Test whether fallocate is available
$CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null <<EOF
#include <fcntl.h>
#include <linux/falloc.h>
int main() {
int fd = open("/dev/null", 0);
fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, 0, 1024);
}
EOF
if [ "$?" = 0 ]; then
COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_FALLOCATE_PRESENT"
if [ "$?" = 0 ]; then
COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_FALLOCATE_PRESENT"
fi
fi
# Test whether Snappy library is installed