V3 [PATCH] test-container: Use xcopy_file_range for cross-device copy [BZ #23597]
H.J. Lu
hjl.tools@gmail.com
Fri Aug 31 20:07:00 GMT 2018
On Fri, Aug 31, 2018 at 12:56 PM, Carlos O'Donell <carlos@redhat.com> wrote:
> On 08/31/2018 03:30 PM, H.J. Lu wrote:
>> From 00e519806af9a7381b1f10d823bcaea5a799916b Mon Sep 17 00:00:00 2001
>> From: "H.J. Lu" <hjl.tools@gmail.com>
>> Date: Fri, 31 Aug 2018 11:26:16 -0700
>> Subject: [PATCH] test-container: Use xcopy_file_range for cross-device copy
>> [BZ #23597]
>>
>> copy_file_range can't be used to copy a file from glibc source directory
>> to glibc build directory since they may be on different filesystems.
>> This patch adds xcopy_file_range for cross-device copy.
>>
>> [BZ #23597]
>> * support/Makefile (libsupport-routines): Add
>> support_copy_file_range and xcopy_file_range.
>> * support/support.h: Include <sys/types.h>.
>> (support_copy_file_range): New prototype.
>> * support/support_copy_file_range.c: New file. Copied and
>> modified from io/copy_file_range-compat.c.
>> * support/test-container.c (copy_one_file): Call xcopy_file_rang
>> instead of copy_file_range.
>> * support/xcopy_file_range.c: New file.
>> * support/xunistd.h (xcopy_file_range): New prototype.
>
> OK if you fix the following:
>
> - xcopy_file_range should continue to return ssize_t (the number of bytes
> copied).
>
> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
>
>> ---
>> support/Makefile | 2 +
>> support/support.h | 5 ++
>> support/support_copy_file_range.c | 143 ++++++++++++++++++++++++++++++
>> support/test-container.c | 3 +-
>> support/xcopy_file_range.c | 31 +++++++
>> support/xunistd.h | 3 +
>> 6 files changed, 185 insertions(+), 2 deletions(-)
>> create mode 100644 support/support_copy_file_range.c
>> create mode 100644 support/xcopy_file_range.c
>>
>> diff --git a/support/Makefile b/support/Makefile
>> index b528f538a6..545bfa2727 100644
>> --- a/support/Makefile
>> +++ b/support/Makefile
>> @@ -43,6 +43,7 @@ libsupport-routines = \
>> support_capture_subprocess \
>> support_capture_subprocess_check \
>> support_chroot \
>> + support_copy_file_range \
>
> OK.
>
>> support_descriptor_supports_holes \
>> support_enter_mount_namespace \
>> support_enter_network_namespace \
>> @@ -74,6 +75,7 @@ libsupport-routines = \
>> xchroot \
>> xclose \
>> xconnect \
>> + xcopy_file_range \
>
> OK.
>
>> xdlfcn \
>> xdup2 \
>> xfclose \
>> diff --git a/support/support.h b/support/support.h
>> index c6ff4bafb4..d0e15bca1d 100644
>> --- a/support/support.h
>> +++ b/support/support.h
>> @@ -27,6 +27,8 @@
>> #include <sys/cdefs.h>
>> /* For mode_t. */
>> #include <sys/stat.h>
>> +/* For ssize_t and off64_t. */
>> +#include <sys/types.h>
>
> OK.
>
>>
>> __BEGIN_DECLS
>>
>> @@ -94,6 +96,9 @@ extern const char support_install_prefix[];
>> /* Corresponds to the install's lib/ or lib64/ directory. */
>> extern const char support_libdir_prefix[];
>>
>> +extern ssize_t support_copy_file_range (int, off64_t *, int, off64_t *,
>> + size_t, unsigned int);
>
> OK.
>
>> +
>> __END_DECLS
>>
>> #endif /* SUPPORT_H */
>> diff --git a/support/support_copy_file_range.c b/support/support_copy_file_range.c
>> new file mode 100644
>> index 0000000000..9a1e39773e
>> --- /dev/null
>> +++ b/support/support_copy_file_range.c
>> @@ -0,0 +1,143 @@
>> +/* Simplified copy_file_range with cross-device copy.
>> + 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 <errno.h>
>> +#include <fcntl.h>
>> +#include <inttypes.h>
>> +#include <limits.h>
>> +#include <sys/stat.h>
>> +#include <sys/types.h>
>> +#include <unistd.h>
>> +#include <support/support.h>
>> +
>> +ssize_t
>> +support_copy_file_range (int infd, __off64_t *pinoff,
>> + int outfd, __off64_t *poutoff,
>> + size_t length, unsigned int flags)
>
> OK.
>
>> +{
>> + if (flags != 0)
>> + {
>> + errno = EINVAL;
>> + return -1;
>> + }
>> +
>> + struct stat64 instat;
>> + struct stat64 outstat;
>> + if (fstat64 (infd, &instat) != 0 || fstat64 (outfd, &outstat) != 0)
>> + return -1;
>> + if (S_ISDIR (instat.st_mode) || S_ISDIR (outstat.st_mode))
>> + {
>> + errno = EISDIR;
>> + return -1;
>> + }
>> + if (!S_ISREG (instat.st_mode) || !S_ISREG (outstat.st_mode))
>> + {
>> + /* We need a regular input file so that the we can seek
>> + backwards in case of a write failure. */
>> + errno = EINVAL;
>> + return -1;
>> + }
>> +
>> + /* The output descriptor must not have O_APPEND set. */
>> + if (fcntl (outfd, F_GETFL) & O_APPEND)
>> + {
>> + errno = EBADF;
>> + return -1;
>> + }
>> +
>> + /* Avoid an overflow in the result. */
>> + if (length > SSIZE_MAX)
>> + length = SSIZE_MAX;
>> +
>> + /* Main copying loop. The buffer size is arbitrary and is a
>> + trade-off between stack size consumption, cache usage, and
>> + amortization of system call overhead. */
>> + size_t copied = 0;
>> + char buf[8192];
>> + while (length > 0)
>> + {
>> + size_t to_read = length;
>> + if (to_read > sizeof (buf))
>> + to_read = sizeof (buf);
>> +
>> + /* Fill the buffer. */
>> + ssize_t read_count;
>> + if (pinoff == NULL)
>> + read_count = read (infd, buf, to_read);
>> + else
>> + read_count = pread64 (infd, buf, to_read, *pinoff);
>> + if (read_count == 0)
>> + /* End of file reached prematurely. */
>> + return copied;
>> + if (read_count < 0)
>> + {
>> + if (copied > 0)
>> + /* Report the number of bytes copied so far. */
>> + return copied;
>> + return -1;
>> + }
>> + if (pinoff != NULL)
>> + *pinoff += read_count;
>> +
>> + /* Write the buffer part which was read to the destination. */
>> + char *end = buf + read_count;
>> + for (char *p = buf; p < end; )
>> + {
>> + ssize_t write_count;
>> + if (poutoff == NULL)
>> + write_count = write (outfd, p, end - p);
>> + else
>> + write_count = pwrite64 (outfd, p, end - p, *poutoff);
>> + if (write_count < 0)
>> + {
>> + /* Adjust the input read position to match what we have
>> + written, so that the caller can pick up after the
>> + error. */
>> + size_t written = p - buf;
>> + /* NB: This needs to be signed so that we can form the
>> + negative value below. */
>> + ssize_t overread = read_count - written;
>> + if (pinoff == NULL)
>> + {
>> + if (overread > 0)
>> + {
>> + /* We are on an error recovery path, so we
>> + cannot deal with failure here. */
>> + int save_errno = errno;
>> + (void) lseek64 (infd, -overread, SEEK_CUR);
>> + errno = save_errno;
>> + }
>> + }
>> + else /* pinoff != NULL */
>> + *pinoff -= overread;
>> +
>> + if (copied + written > 0)
>> + /* Report the number of bytes copied so far. */
>> + return copied + written;
>> + return -1;
>> + }
>> + p += write_count;
>> + if (poutoff != NULL)
>> + *poutoff += write_count;
>> + } /* Write loop. */
>> +
>> + copied += read_count;
>> + length -= read_count;
>> + }
>> + return copied;
>
> OK.
>
>> +}
>> diff --git a/support/test-container.c b/support/test-container.c
>> index 2e91bdf9ec..c56b53ed81 100644
>> --- a/support/test-container.c
>> +++ b/support/test-container.c
>> @@ -383,8 +383,7 @@ copy_one_file (const char *sname, const char *dname)
>> if (dfd < 0)
>> FAIL_EXIT1 ("unable to open %s for writing\n", dname);
>>
>> - if (copy_file_range (sfd, 0, dfd, 0, st.st_size, 0) != st.st_size)
>> - FAIL_EXIT1 ("cannot copy file %s to %s\n", sname, dname);
>> + xcopy_file_range (sfd, 0, dfd, 0, st.st_size, 0);
>
> OK. Exactly, just the bare copy which we expect to succeed.
>
>>
>> xclose (sfd);
>> xclose (dfd);
>> diff --git a/support/xcopy_file_range.c b/support/xcopy_file_range.c
>> new file mode 100644
>> index 0000000000..2df6b1cc16
>> --- /dev/null
>> +++ b/support/xcopy_file_range.c
>> @@ -0,0 +1,31 @@
>> +/* copy_file_range with error checking.
>> + 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 <support/support.h>
>> +#include <support/xunistd.h>
>> +#include <support/check.h>
>> +
>> +void
>
> No, this should return ssize_t.
>
>> +xcopy_file_range (int infd, off64_t *pinoff, int outfd, off64_t *poutoff,
>> + size_t length, unsigned int flags)
>> +{
>> +
>> + if (support_copy_file_range (infd, pinoff, outfd, poutoff, length,
>> + flags) != length)
>> + FAIL_EXIT1 ("cannot copy file: %m\n");
>
> This should check for return == -1 and FAIL_EXIT1, otherwise pass the
> result back to the caller.
>
> xcopy_file_range should have the semantics that it FAIL_EXIT1 on error,
> but otherwise works as intended.
>
>> +}
>> diff --git a/support/xunistd.h b/support/xunistd.h
>> index cdd4e8d92d..6da6525a1f 100644
>> --- a/support/xunistd.h
>> +++ b/support/xunistd.h
>> @@ -64,6 +64,9 @@ void *xmmap (void *addr, size_t length, int prot, int flags, int fd);
>> void xmprotect (void *addr, size_t length, int prot);
>> void xmunmap (void *addr, size_t length);
>>
>> +void xcopy_file_range(int fd_in, loff_t *off_in, int fd_out,
>> + loff_t *off_out, size_t len, unsigned int flags);
>
> Not OK, should result ssize_t.
>
>> +
>> __END_DECLS
>>
>> #endif /* SUPPORT_XUNISTD_H */
>> -- 2.17.1
>
This is the updated patch I am checking in.
Thanks.
--
H.J.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-test-container-Use-xcopy_file_range-for-cross-device.patch
Type: text/x-patch
Size: 9410 bytes
Desc: not available
URL: <http://sourceware.org/pipermail/libc-alpha/attachments/20180831/0dc68c59/attachment.bin>
More information about the Libc-alpha
mailing list