On Tue, Nov 12, 2019 at 06:44:16PM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > Dave Chinner reports[1] that an appending AIO DIO write to the second > block of a zero-length file and an fallocate request to the first block > of the same file can race to set isize, with the user-visible end result > that the file size is set incorrectly to one block long. Write a small > test to reproduce the results. > > [1] https://lore.kernel.org/linux-xfs/20191029100342.GA41131@bfoster/T/ > > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > --- > .../aio-dio-append-write-fallocate-race.c | 212 ++++++++++++++++++++ I added an entry in .gitignore for it. > tests/generic/722 | 43 ++++ > tests/generic/722.out | 2 > tests/generic/group | 1 > 4 files changed, 258 insertions(+) > create mode 100644 src/aio-dio-regress/aio-dio-append-write-fallocate-race.c > create mode 100755 tests/generic/722 > create mode 100644 tests/generic/722.out > > diff --git a/src/aio-dio-regress/aio-dio-append-write-fallocate-race.c b/src/aio-dio-regress/aio-dio-append-write-fallocate-race.c > new file mode 100644 > index 00000000..091b047d > --- /dev/null > +++ b/src/aio-dio-regress/aio-dio-append-write-fallocate-race.c > @@ -0,0 +1,212 @@ > +// SPDX-License-Identifier: GPL-2.0-or-newer > +/* > + * Copyright (c) 2019 Oracle. > + * All Rights Reserved. > + * > + * Race appending aio dio and fallocate to make sure we get the correct file > + * size afterwards. > + */ > +#include <stdio.h> > +#include <pthread.h> > +#include <sys/types.h> > +#include <sys/stat.h> > +#include <fcntl.h> > +#include <unistd.h> > +#include <string.h> > +#include <errno.h> > +#include <libaio.h> > +#include <stdlib.h> > +#include <stdbool.h> > +#include <limits.h> > + > +static int fd; > +static int blocksize; > + > +static void * > +falloc_thread( > + void *p) > +{ > + int ret; > + > + ret = fallocate(fd, 0, 0, blocksize); > + if (ret) > + perror("falloc"); > + > + return NULL; > +} > + > +static int > +test( > + const char *fname, > + unsigned int iteration, > + unsigned int *passed) > +{ > + struct stat sbuf; > + pthread_t thread; > + io_context_t ioctx = 0; > + struct iocb iocb; > + struct iocb *iocbp = &iocb; > + struct io_event event; > + char *buf; > + bool wait_thread = false; > + int ret; > + > + /* Truncate file, allocate resources for doing IO. */ > + fd = open(fname, O_DIRECT | O_RDWR | O_TRUNC | O_CREAT, 0644); > + if (fd < 0) { > + perror(fname); > + return -1; > + } > + > + ret = fstat(fd, &sbuf); > + if (ret) { > + perror(fname); > + goto out; > + } > + blocksize = sbuf.st_blksize; > + > + ret = posix_memalign((void **)&buf, blocksize, blocksize); > + if (ret) { > + errno = ret; > + perror("buffer"); > + goto out; > + } > + memset(buf, 'X', blocksize); > + memset(&event, 0, sizeof(event)); > + > + ret = io_queue_init(1, &ioctx); > + if (ret) { > + errno = -ret; > + perror("io_queue_init"); > + goto out_buf; > + } > + > + /* > + * Set ourselves up to race fallocate(0..blocksize) with aio dio > + * pwrite(blocksize..blocksize * 2). This /should/ give us a file > + * with length (2 * blocksize). > + */ > + io_prep_pwrite(&iocb, fd, buf, blocksize, blocksize); > + > + ret = pthread_create(&thread, NULL, falloc_thread, NULL); > + if (ret) { > + errno = ret; > + perror("pthread"); > + goto out_io; > + } > + wait_thread = true; > + > + ret = io_submit(ioctx, 1, &iocbp); > + if (ret != 1) { > + errno = -ret; > + perror("io_submit"); > + goto out_join; > + } > + > + ret = io_getevents(ioctx, 1, 1, &event, NULL); > + if (ret != 1) { > + errno = -ret; > + perror("io_getevents"); > + goto out_join; > + } > + > + if (event.res < 0) { > + errno = -event.res; > + perror("io_event.res"); > + goto out_join; > + } > + > + if (event.res2 < 0) { > + errno = -event.res2; > + perror("io_event.res2"); > + goto out_join; > + } > + > + wait_thread = false; > + ret = pthread_join(thread, NULL); > + if (ret) { > + errno = ret; > + perror("join"); > + goto out_io; > + } > + > + /* Make sure we actually got a file of size (2 * blocksize). */ > + ret = fstat(fd, &sbuf); > + if (ret) { > + perror(fname); > + goto out_buf; > + } > + > + if (sbuf.st_size != 2 * blocksize) { > + fprintf(stderr, "[%u]: sbuf.st_size=%llu, expected %llu.\n", > + iteration, > + (unsigned long long)sbuf.st_size, > + (unsigned long long)2 * blocksize); > + } else { > + printf("[%u]: passed.\n", iteration); > + (*passed)++; > + } > + > +out_join: > + if (wait_thread) { > + ret = pthread_join(thread, NULL); > + if (ret) { > + errno = ret; > + perror("join"); > + goto out_io; > + } > + } > +out_io: > + ret = io_queue_release(ioctx); > + if (ret) { > + errno = -ret; > + perror("io_queue_release"); > + } > + > +out_buf: > + free(buf); > +out: > + ret = close(fd); > + fd = -1; > + if (ret) { > + perror("close"); > + return -1; > + } > + > + return 0; > +} > + > +int main(int argc, char *argv[]) > +{ > + int ret; > + long l; > + unsigned int i; > + unsigned int passed = 0; > + > + if (argc != 3) { > + printf("Usage: %s filename iterations\n", argv[0]); > + return 1; > + } > + > + errno = 0; > + l = strtol(argv[2], NULL, 0); > + if (errno) { > + perror(argv[2]); > + return 1; > + } > + if (l < 1 || l > UINT_MAX) { > + fprintf(stderr, "%ld: must be between 1 and %u.\n", > + l, UINT_MAX); > + return 1; > + } > + > + for (i = 0; i < l; i++) { > + ret = test(argv[1], i, &passed); > + if (ret) > + return 1; > + } > + > + printf("pass rate: %u/%u (%.2f%%)\n", passed, i, 100.0 * passed / i); > + > + return 0; > +} > diff --git a/tests/generic/722 b/tests/generic/722 > new file mode 100755 > index 00000000..937abf36 > --- /dev/null > +++ b/tests/generic/722 > @@ -0,0 +1,43 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0-or-later > +# Copyright (c) 2019, Oracle and/or its affiliates. All Rights Reserved. > +# > +# FS QA Test No. 722 > +# > +# Race an appending aio dio write to the second block of a file while > +# simultaneously fallocating to the first block. Make sure that we end up > +# with a two-block file. > + > +seq=`basename $0` > +seqres=$RESULT_DIR/$seq > +echo "QA output created by $seq" > + > +here=`pwd` > +tmp=/tmp/$$ > +status=1 # failure is the default! > +trap "_cleanup; exit \$status" 0 1 2 3 15 > + > +_cleanup() > +{ > + cd / > + rm -f $tmp.* $testfile > +} > + > +# get standard environment, filters and checks > +. ./common/rc > + > +# real QA test starts here > +_supported_os Linux > +_supported_fs generic > +_require_aiodio "aio-dio-append-write-fallocate-race" > +_require_test Also added _require_xfs_io_command "falloc" Thanks, Eryu > + > +rm -f $seqres.full > + > +testfile=$TEST_DIR/test-$seq > +$AIO_TEST $testfile 100 >> $seqres.full > + > +echo Silence is golden. > +# success, all done > +status=0 > +exit > diff --git a/tests/generic/722.out b/tests/generic/722.out > new file mode 100644 > index 00000000..8621a87d > --- /dev/null > +++ b/tests/generic/722.out > @@ -0,0 +1,2 @@ > +QA output created by 722 > +Silence is golden. > diff --git a/tests/generic/group b/tests/generic/group > index e5d0c1da..308f86f2 100644 > --- a/tests/generic/group > +++ b/tests/generic/group > @@ -588,3 +588,4 @@ > 583 auto quick encrypt > 584 auto quick encrypt > 585 auto rename > +722 auto quick rw falloc
