Message ID | 20180713121033.7626643994575@oldenburg.str.redhat.com |
---|---|
State | New |
Headers | show |
Series | io: Avoid running some tests if the file system does not support holes | expand |
On 13/07/2018 09:10, Florian Weimer wrote: > Otherwise, these tests fills up the entire disk (or just run very slowly > and eventually time out). > > 2018-07-13 Florian Weimer <fweimer@redhat.com> > > * support/support_descriptor_supports_holes.c: New file. > * support/Makefile (libsupport-routines): Add > support_descriptor_supports_holes. > * support/support.h (support_descriptor_supports_holes): Declare. > * io/tst-copy_file_range.c: Call support_descriptor_supports_holes > and stop testing if holes are not supported. > * io/test-lfs.c (do_prepare): Likewise. > * sysdeps/unix/sysv/linux/tst-fallocate-common.c (do_prepare): > Likewise. LGTM with just a clarification below. > > diff --git a/io/test-lfs.c b/io/test-lfs.c > index f7721a5995..52120e9bca 100644 > --- a/io/test-lfs.c > +++ b/io/test-lfs.c > @@ -25,6 +25,7 @@ > #include <error.h> > #include <errno.h> > #include <sys/resource.h> > +#include <support/check.h> > > /* Prototype for our test function. */ > extern void do_prepare (int argc, char *argv[]); > @@ -70,6 +71,8 @@ do_prepare (int argc, char *argv[]) > else > error (EXIT_FAILURE, errno, "cannot create temporary file"); > } > + if (!support_descriptor_supports_holes (fd)) > + FAIL_UNSUPPORTED ("File %s does not support holes", name); > add_temp_file (name); > > if (getrlimit64 (RLIMIT_FSIZE, &rlim) != 0) > diff --git a/io/tst-copy_file_range.c b/io/tst-copy_file_range.c > index 3d531a1937..e5b46f91db 100644 > --- a/io/tst-copy_file_range.c > +++ b/io/tst-copy_file_range.c > @@ -739,7 +739,12 @@ do_test (void) > *p = rand () >> 24; > > infd = create_temp_file ("tst-copy_file_range-in-", &infile); > - xclose (create_temp_file ("tst-copy_file_range-out-", &outfile)); > + { > + int outfd = create_temp_file ("tst-copy_file_range-out-", &outfile); > + if (!support_descriptor_supports_holes (outfd)) > + FAIL_UNSUPPORTED ("File %s does not support holes", outfile); > + xclose (outfd); > + } > > /* Try to find a different directory from the default input/output > file. */ > diff --git a/support/Makefile b/support/Makefile > index 652d2cdf69..9063046c23 100644 > --- a/support/Makefile > +++ b/support/Makefile > @@ -43,6 +43,7 @@ libsupport-routines = \ > support_capture_subprocess \ > support_capture_subprocess_check \ > support_chroot \ > + support_descriptor_supports_holes \ > support_enter_mount_namespace \ > support_enter_network_namespace \ > support_format_address_family \ > diff --git a/support/support.h b/support/support.h > index b61fe0735c..34ae6e10cd 100644 > --- a/support/support.h > +++ b/support/support.h > @@ -65,6 +65,12 @@ void support_write_file_string (const char *path, const char *contents); > the result). */ > char *support_quote_blob (const void *blob, size_t length); > > +/* Returns non-zero if the file descriptor is a regular file on a file > + system which supports holes (that is, seeking and writing does not > + allocate storage for the range of zeros). FD must refer to a > + regular file open for writing, and initially empty. */ > +int support_descriptor_supports_holes (int fd); > + > /* Error-checking wrapper functions which terminate the process on > error. */ > > diff --git a/support/support_descriptor_supports_holes.c b/support/support_descriptor_supports_holes.c > new file mode 100644 > index 0000000000..b04498664e > --- /dev/null > +++ b/support/support_descriptor_supports_holes.c > @@ -0,0 +1,80 @@ > +/* Test for file system hole support. > + Copyright (C) 2018 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <http://www.gnu.org/licenses/>. */ > + > +#include <stdbool.h> > +#include <support.h> > +#include <support/check.h> > +#include <sys/stat.h> > +#include <xunistd.h> > + > +int > +support_descriptor_supports_holes (int fd) > +{ > + enum > + { > + /* Write offset for the enlarged file. This value is arbitrary > + and hopefully large enough to trigger the creation of holes. > + We cannot use the file system block size as a reference here > + because it is incorrect for network file systems. */ > + write_offset = 16 * 1024 * 1024, > + > + /* Our write may add this number of additional blocks. */ > + block_headroom = 8, Is this number based on 512 physical block size with a 4kb page size? If so, shouldn't we try to determine this at runtime? > + }; > + > + struct stat64 st; > + xfstat (fd, &st); > + if (!S_ISREG (st.st_mode)) > + FAIL_EXIT1 ("descriptor %d does not refer to a regular file", fd); > + if (st.st_size != 0) > + FAIL_EXIT1 ("descriptor %d does not refer to an empty file", fd); > + if (st.st_blocks > block_headroom) > + FAIL_EXIT1 ("descriptor %d refers to a pre-allocated file (%lld blocks)", > + fd, (long long int) st.st_blocks); > + > + /* Write a single byte at the start of the file to compute the block > + usage for a single byte. */ > + xlseek (fd, 0, SEEK_SET); > + char b = '@'; > + xwrite (fd, &b, 1); > + /* Attempt to bypass delayed allocation. */ > + TEST_COMPARE (fsync (fd), 0); > + xfstat (fd, &st); > + unsigned long long int block_limit = 2 * st.st_blocks + block_headroom; > + > + /* Write a single byte at 16 megabytes. */ > + xlseek (fd, write_offset, SEEK_SET); > + xwrite (fd, &b, 1); > + /* Attempt to bypass delayed allocation. */ > + TEST_COMPARE (fsync (fd), 0); > + xfstat (fd, &st); > + bool supports_holes = st.st_blocks <= block_limit; > + > + /* Also check that extending the file does not fill up holes. */ > + xftruncate (fd, 2 * write_offset); > + /* Attempt to bypass delayed allocation. */ > + TEST_COMPARE (fsync (fd), 0); > + xfstat (fd, &st); > + supports_holes = supports_holes && st.st_blocks <= block_limit; > + > + /* Return to a zero-length file. */ > + xftruncate (fd, 0); > + xlseek (fd, 0, SEEK_SET); > + > + return supports_holes; > +} > diff --git a/sysdeps/unix/sysv/linux/tst-fallocate-common.c b/sysdeps/unix/sysv/linux/tst-fallocate-common.c > index a6ba403c62..bc54cf5134 100644 > --- a/sysdeps/unix/sysv/linux/tst-fallocate-common.c > +++ b/sysdeps/unix/sysv/linux/tst-fallocate-common.c > @@ -41,6 +41,8 @@ do_prepare (int argc, char **argv) > temp_fd = create_temp_file ("tst-fallocate.", &temp_filename); > if (temp_fd == -1) > FAIL_EXIT1 ("cannot create temporary file: %m"); > + if (!support_descriptor_supports_holes (temp_fd)) > + FAIL_UNSUPPORTED ("File %s does not support holes", temp_filename); > } > #define PREPARE do_prepare > >
* Adhemerval Zanella: >> + /* Our write may add this number of additional blocks. */ >> + block_headroom = 8, > > Is this number based on 512 physical block size with a 4kb page size? > If so, shouldn't we try to determine this at runtime? It's just an arbitrary number in case the file system needs blocks to store large holes or something like that. I can make the number 11 to make this more obvious, and expand the comment. timezone/tst-tzset.c needs a similar check, so I have to send a new patch anyway.
diff --git a/io/test-lfs.c b/io/test-lfs.c index f7721a5995..52120e9bca 100644 --- a/io/test-lfs.c +++ b/io/test-lfs.c @@ -25,6 +25,7 @@ #include <error.h> #include <errno.h> #include <sys/resource.h> +#include <support/check.h> /* Prototype for our test function. */ extern void do_prepare (int argc, char *argv[]); @@ -70,6 +71,8 @@ do_prepare (int argc, char *argv[]) else error (EXIT_FAILURE, errno, "cannot create temporary file"); } + if (!support_descriptor_supports_holes (fd)) + FAIL_UNSUPPORTED ("File %s does not support holes", name); add_temp_file (name); if (getrlimit64 (RLIMIT_FSIZE, &rlim) != 0) diff --git a/io/tst-copy_file_range.c b/io/tst-copy_file_range.c index 3d531a1937..e5b46f91db 100644 --- a/io/tst-copy_file_range.c +++ b/io/tst-copy_file_range.c @@ -739,7 +739,12 @@ do_test (void) *p = rand () >> 24; infd = create_temp_file ("tst-copy_file_range-in-", &infile); - xclose (create_temp_file ("tst-copy_file_range-out-", &outfile)); + { + int outfd = create_temp_file ("tst-copy_file_range-out-", &outfile); + if (!support_descriptor_supports_holes (outfd)) + FAIL_UNSUPPORTED ("File %s does not support holes", outfile); + xclose (outfd); + } /* Try to find a different directory from the default input/output file. */ diff --git a/support/Makefile b/support/Makefile index 652d2cdf69..9063046c23 100644 --- a/support/Makefile +++ b/support/Makefile @@ -43,6 +43,7 @@ libsupport-routines = \ support_capture_subprocess \ support_capture_subprocess_check \ support_chroot \ + support_descriptor_supports_holes \ support_enter_mount_namespace \ support_enter_network_namespace \ support_format_address_family \ diff --git a/support/support.h b/support/support.h index b61fe0735c..34ae6e10cd 100644 --- a/support/support.h +++ b/support/support.h @@ -65,6 +65,12 @@ void support_write_file_string (const char *path, const char *contents); the result). */ char *support_quote_blob (const void *blob, size_t length); +/* Returns non-zero if the file descriptor is a regular file on a file + system which supports holes (that is, seeking and writing does not + allocate storage for the range of zeros). FD must refer to a + regular file open for writing, and initially empty. */ +int support_descriptor_supports_holes (int fd); + /* Error-checking wrapper functions which terminate the process on error. */ diff --git a/support/support_descriptor_supports_holes.c b/support/support_descriptor_supports_holes.c new file mode 100644 index 0000000000..b04498664e --- /dev/null +++ b/support/support_descriptor_supports_holes.c @@ -0,0 +1,80 @@ +/* Test for file system hole support. + Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <stdbool.h> +#include <support.h> +#include <support/check.h> +#include <sys/stat.h> +#include <xunistd.h> + +int +support_descriptor_supports_holes (int fd) +{ + enum + { + /* Write offset for the enlarged file. This value is arbitrary + and hopefully large enough to trigger the creation of holes. + We cannot use the file system block size as a reference here + because it is incorrect for network file systems. */ + write_offset = 16 * 1024 * 1024, + + /* Our write may add this number of additional blocks. */ + block_headroom = 8, + }; + + struct stat64 st; + xfstat (fd, &st); + if (!S_ISREG (st.st_mode)) + FAIL_EXIT1 ("descriptor %d does not refer to a regular file", fd); + if (st.st_size != 0) + FAIL_EXIT1 ("descriptor %d does not refer to an empty file", fd); + if (st.st_blocks > block_headroom) + FAIL_EXIT1 ("descriptor %d refers to a pre-allocated file (%lld blocks)", + fd, (long long int) st.st_blocks); + + /* Write a single byte at the start of the file to compute the block + usage for a single byte. */ + xlseek (fd, 0, SEEK_SET); + char b = '@'; + xwrite (fd, &b, 1); + /* Attempt to bypass delayed allocation. */ + TEST_COMPARE (fsync (fd), 0); + xfstat (fd, &st); + unsigned long long int block_limit = 2 * st.st_blocks + block_headroom; + + /* Write a single byte at 16 megabytes. */ + xlseek (fd, write_offset, SEEK_SET); + xwrite (fd, &b, 1); + /* Attempt to bypass delayed allocation. */ + TEST_COMPARE (fsync (fd), 0); + xfstat (fd, &st); + bool supports_holes = st.st_blocks <= block_limit; + + /* Also check that extending the file does not fill up holes. */ + xftruncate (fd, 2 * write_offset); + /* Attempt to bypass delayed allocation. */ + TEST_COMPARE (fsync (fd), 0); + xfstat (fd, &st); + supports_holes = supports_holes && st.st_blocks <= block_limit; + + /* Return to a zero-length file. */ + xftruncate (fd, 0); + xlseek (fd, 0, SEEK_SET); + + return supports_holes; +} diff --git a/sysdeps/unix/sysv/linux/tst-fallocate-common.c b/sysdeps/unix/sysv/linux/tst-fallocate-common.c index a6ba403c62..bc54cf5134 100644 --- a/sysdeps/unix/sysv/linux/tst-fallocate-common.c +++ b/sysdeps/unix/sysv/linux/tst-fallocate-common.c @@ -41,6 +41,8 @@ do_prepare (int argc, char **argv) temp_fd = create_temp_file ("tst-fallocate.", &temp_filename); if (temp_fd == -1) FAIL_EXIT1 ("cannot create temporary file: %m"); + if (!support_descriptor_supports_holes (temp_fd)) + FAIL_UNSUPPORTED ("File %s does not support holes", temp_filename); } #define PREPARE do_prepare