| Message ID | 046cc1b4dc00f8fb8997ec6ebedc9b3625f34c1c.1741087191.git.ritesh.list@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | xfsprogs: Add support for preadv2() and RWF_DONTCACHE | expand |
On Tue, Mar 04, 2025 at 05:25:35PM +0530, Ritesh Harjani (IBM) wrote: > preadv2() was introduced in Linux 4.6. This patch adds support for > preadv2() to xfs_io. > > Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> > --- > configure.ac | 1 + > include/builddefs.in | 1 + > io/Makefile | 4 ++++ > io/pread.c | 45 ++++++++++++++++++++++++++++--------------- > m4/package_libcdev.m4 | 18 +++++++++++++++++ > 5 files changed, 54 insertions(+), 15 deletions(-) > > diff --git a/configure.ac b/configure.ac > index 8c76f398..658117ad 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -153,6 +153,7 @@ AC_PACKAGE_NEED_URCU_H > AC_PACKAGE_NEED_RCU_INIT > > AC_HAVE_PWRITEV2 > +AC_HAVE_PREADV2 I wonder, will we ever encounter a C library that has pwritev2 and /not/ preadv2? > AC_HAVE_COPY_FILE_RANGE > AC_NEED_INTERNAL_FSXATTR > AC_NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG > diff --git a/include/builddefs.in b/include/builddefs.in > index 82840ec7..a11d201c 100644 > --- a/include/builddefs.in > +++ b/include/builddefs.in > @@ -94,6 +94,7 @@ ENABLE_SCRUB = @enable_scrub@ > HAVE_ZIPPED_MANPAGES = @have_zipped_manpages@ > > HAVE_PWRITEV2 = @have_pwritev2@ > +HAVE_PREADV2 = @have_preadv2@ > HAVE_COPY_FILE_RANGE = @have_copy_file_range@ > NEED_INTERNAL_FSXATTR = @need_internal_fsxattr@ > NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG = @need_internal_fscrypt_add_key_arg@ > diff --git a/io/Makefile b/io/Makefile > index 8f835ec7..f8b19ac5 100644 > --- a/io/Makefile > +++ b/io/Makefile > @@ -69,6 +69,10 @@ ifeq ($(HAVE_PWRITEV2),yes) > LCFLAGS += -DHAVE_PWRITEV2 > endif > > +ifeq ($(HAVE_PREADV2),yes) > +LCFLAGS += -DHAVE_PREADV2 > +endif > + > ifeq ($(HAVE_MAP_SYNC),yes) > LCFLAGS += -DHAVE_MAP_SYNC > endif > diff --git a/io/pread.c b/io/pread.c > index 62c771fb..782f2a36 100644 > --- a/io/pread.c > +++ b/io/pread.c > @@ -162,7 +162,8 @@ static ssize_t > do_preadv( > int fd, > off_t offset, > - long long count) > + long long count, > + int preadv2_flags) Nit: ^ space before tab. There's a bunch more of thense, every time a "preadv2_flags" variable or parameter are declared. > { > int vecs = 0; > ssize_t oldlen = 0; > @@ -181,8 +182,14 @@ do_preadv( > } else { > vecs = vectors; > } > +#ifdef HAVE_PREADV2 > + if (preadv2_flags) > + bytes = preadv2(fd, iov, vectors, offset, preadv2_flags); > + else > + bytes = preadv(fd, iov, vectors, offset); > +#else > bytes = preadv(fd, iov, vectors, offset); > - > +#endif Can we have the case that preadv2_flags!=0 and HAVE_PREADV2 isn't defined? If so, then there ought to be a warning about that. --D > /* restore trimmed iov */ > if (oldlen) > iov[vecs - 1].iov_len = oldlen; > @@ -195,12 +202,13 @@ do_pread( > int fd, > off_t offset, > long long count, > - size_t buffer_size) > + size_t buffer_size, > + int preadv2_flags) > { > if (!vectors) > return pread(fd, io_buffer, min(count, buffer_size), offset); > > - return do_preadv(fd, offset, count); > + return do_preadv(fd, offset, count, preadv2_flags); > } > > static int > @@ -210,7 +218,8 @@ read_random( > long long count, > long long *total, > unsigned int seed, > - int eof) > + int eof, > + int preadv2_flags) > { > off_t end, off, range; > ssize_t bytes; > @@ -234,7 +243,7 @@ read_random( > io_buffersize; > else > off = offset; > - bytes = do_pread(fd, off, io_buffersize, io_buffersize); > + bytes = do_pread(fd, off, io_buffersize, io_buffersize, preadv2_flags); > if (bytes == 0) > break; > if (bytes < 0) { > @@ -256,7 +265,8 @@ read_backward( > off_t *offset, > long long *count, > long long *total, > - int eof) > + int eof, > + int preadv2_flags) > { > off_t end, off = *offset; > ssize_t bytes = 0, bytes_requested; > @@ -276,7 +286,7 @@ read_backward( > /* Do initial unaligned read if needed */ > if ((bytes_requested = (off % io_buffersize))) { > off -= bytes_requested; > - bytes = do_pread(fd, off, bytes_requested, io_buffersize); > + bytes = do_pread(fd, off, bytes_requested, io_buffersize, preadv2_flags); > if (bytes == 0) > return ops; > if (bytes < 0) { > @@ -294,7 +304,7 @@ read_backward( > while (cnt > end) { > bytes_requested = min(cnt, io_buffersize); > off -= bytes_requested; > - bytes = do_pread(fd, off, cnt, io_buffersize); > + bytes = do_pread(fd, off, cnt, io_buffersize, preadv2_flags); > if (bytes == 0) > break; > if (bytes < 0) { > @@ -318,14 +328,15 @@ read_forward( > long long *total, > int verbose, > int onlyone, > - int eof) > + int eof, > + int preadv2_flags) > { > ssize_t bytes; > int ops = 0; > > *total = 0; > while (count > 0 || eof) { > - bytes = do_pread(fd, offset, count, io_buffersize); > + bytes = do_pread(fd, offset, count, io_buffersize, preadv2_flags); > if (bytes == 0) > break; > if (bytes < 0) { > @@ -353,7 +364,7 @@ read_buffer( > int verbose, > int onlyone) > { > - return read_forward(fd, offset, count, total, verbose, onlyone, 0); > + return read_forward(fd, offset, count, total, verbose, onlyone, 0, 0); > } > > static int > @@ -371,6 +382,7 @@ pread_f( > int Cflag, qflag, uflag, vflag; > int eof = 0, direction = IO_FORWARD; > int c; > + int preadv2_flags = 0; > > Cflag = qflag = uflag = vflag = 0; > init_cvtnum(&fsblocksize, &fssectsize); > @@ -463,15 +475,18 @@ pread_f( > case IO_RANDOM: > if (!zeed) /* srandom seed */ > zeed = time(NULL); > - c = read_random(file->fd, offset, count, &total, zeed, eof); > + c = read_random(file->fd, offset, count, &total, zeed, eof, > + preadv2_flags); > break; > case IO_FORWARD: > - c = read_forward(file->fd, offset, count, &total, vflag, 0, eof); > + c = read_forward(file->fd, offset, count, &total, vflag, 0, eof, > + preadv2_flags); > if (eof) > count = total; > break; > case IO_BACKWARD: > - c = read_backward(file->fd, &offset, &count, &total, eof); > + c = read_backward(file->fd, &offset, &count, &total, eof, > + preadv2_flags); > break; > default: > ASSERT(0); > diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4 > index 4ef7e8f6..5a1f748a 100644 > --- a/m4/package_libcdev.m4 > +++ b/m4/package_libcdev.m4 > @@ -16,6 +16,24 @@ pwritev2(0, 0, 0, 0, 0); > AC_SUBST(have_pwritev2) > ]) > > +# > +# Check if we have a preadv2 libc call (Linux) > +# > +AC_DEFUN([AC_HAVE_PREADV2], > + [ AC_MSG_CHECKING([for preadv2]) > + AC_LINK_IFELSE( > + [ AC_LANG_PROGRAM([[ > +#define _GNU_SOURCE > +#include <sys/uio.h> > + ]], [[ > +preadv2(0, 0, 0, 0, 0); > + ]]) > + ], have_preadv2=yes > + AC_MSG_RESULT(yes), > + AC_MSG_RESULT(no)) > + AC_SUBST(have_preadv2) > + ]) > + > # > # Check if we have a copy_file_range system call (Linux) > # > -- > 2.48.1 > >
"Darrick J. Wong" <djwong@kernel.org> writes: > On Tue, Mar 04, 2025 at 05:25:35PM +0530, Ritesh Harjani (IBM) wrote: >> preadv2() was introduced in Linux 4.6. This patch adds support for >> preadv2() to xfs_io. >> >> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> >> --- >> configure.ac | 1 + >> include/builddefs.in | 1 + >> io/Makefile | 4 ++++ >> io/pread.c | 45 ++++++++++++++++++++++++++++--------------- >> m4/package_libcdev.m4 | 18 +++++++++++++++++ >> 5 files changed, 54 insertions(+), 15 deletions(-) >> >> diff --git a/configure.ac b/configure.ac >> index 8c76f398..658117ad 100644 >> --- a/configure.ac >> +++ b/configure.ac >> @@ -153,6 +153,7 @@ AC_PACKAGE_NEED_URCU_H >> AC_PACKAGE_NEED_RCU_INIT >> >> AC_HAVE_PWRITEV2 >> +AC_HAVE_PREADV2 > > I wonder, will we ever encounter a C library that has pwritev2 and /not/ > preadv2? > Sure make sense. I will use Makefile to detect if we have support of HAVE_PWRITEV2 to also define HAVE_PREADV2 (instead of using autoconf). >> AC_HAVE_COPY_FILE_RANGE >> AC_NEED_INTERNAL_FSXATTR >> AC_NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG >> diff --git a/include/builddefs.in b/include/builddefs.in >> index 82840ec7..a11d201c 100644 >> --- a/include/builddefs.in >> +++ b/include/builddefs.in >> @@ -94,6 +94,7 @@ ENABLE_SCRUB = @enable_scrub@ >> HAVE_ZIPPED_MANPAGES = @have_zipped_manpages@ >> >> HAVE_PWRITEV2 = @have_pwritev2@ >> +HAVE_PREADV2 = @have_preadv2@ >> HAVE_COPY_FILE_RANGE = @have_copy_file_range@ >> NEED_INTERNAL_FSXATTR = @need_internal_fsxattr@ >> NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG = @need_internal_fscrypt_add_key_arg@ >> diff --git a/io/Makefile b/io/Makefile >> index 8f835ec7..f8b19ac5 100644 >> --- a/io/Makefile >> +++ b/io/Makefile >> @@ -69,6 +69,10 @@ ifeq ($(HAVE_PWRITEV2),yes) >> LCFLAGS += -DHAVE_PWRITEV2 >> endif >> >> +ifeq ($(HAVE_PREADV2),yes) >> +LCFLAGS += -DHAVE_PREADV2 >> +endif >> + >> ifeq ($(HAVE_MAP_SYNC),yes) >> LCFLAGS += -DHAVE_MAP_SYNC >> endif >> diff --git a/io/pread.c b/io/pread.c >> index 62c771fb..782f2a36 100644 >> --- a/io/pread.c >> +++ b/io/pread.c >> @@ -162,7 +162,8 @@ static ssize_t >> do_preadv( >> int fd, >> off_t offset, >> - long long count) >> + long long count, >> + int preadv2_flags) > > Nit: ^ space before tab. There's a bunch more of thense, every > time a "preadv2_flags" variable or parameter are declared. > Ohk, sorry about that. Let me fix these in v2. >> { >> int vecs = 0; >> ssize_t oldlen = 0; >> @@ -181,8 +182,14 @@ do_preadv( >> } else { >> vecs = vectors; >> } >> +#ifdef HAVE_PREADV2 >> + if (preadv2_flags) >> + bytes = preadv2(fd, iov, vectors, offset, preadv2_flags); >> + else >> + bytes = preadv(fd, iov, vectors, offset); >> +#else >> bytes = preadv(fd, iov, vectors, offset); >> - >> +#endif > > Can we have the case that preadv2_flags!=0 and HAVE_PREADV2 isn't > defined? If so, then there ought to be a warning about that. > That won't happen. Since case 'U' to take input flags is defined under #ifdef HAVE_PREADV2. So if someone tries to set preadv2_flags using -U when HAVE_PREADV2 is not true, it will go into default case where we will use exitcode 1 and print command_usage() > --D > Thanks for the quick review. -ritesh >> /* restore trimmed iov */ >> if (oldlen) >> iov[vecs - 1].iov_len = oldlen; >> @@ -195,12 +202,13 @@ do_pread( >> int fd, >> off_t offset, >> long long count, >> - size_t buffer_size) >> + size_t buffer_size, >> + int preadv2_flags) >> { >> if (!vectors) >> return pread(fd, io_buffer, min(count, buffer_size), offset); >> >> - return do_preadv(fd, offset, count); >> + return do_preadv(fd, offset, count, preadv2_flags); >> } >> >> static int >> @@ -210,7 +218,8 @@ read_random( >> long long count, >> long long *total, >> unsigned int seed, >> - int eof) >> + int eof, >> + int preadv2_flags) >> { >> off_t end, off, range; >> ssize_t bytes; >> @@ -234,7 +243,7 @@ read_random( >> io_buffersize; >> else >> off = offset; >> - bytes = do_pread(fd, off, io_buffersize, io_buffersize); >> + bytes = do_pread(fd, off, io_buffersize, io_buffersize, preadv2_flags); >> if (bytes == 0) >> break; >> if (bytes < 0) { >> @@ -256,7 +265,8 @@ read_backward( >> off_t *offset, >> long long *count, >> long long *total, >> - int eof) >> + int eof, >> + int preadv2_flags) >> { >> off_t end, off = *offset; >> ssize_t bytes = 0, bytes_requested; >> @@ -276,7 +286,7 @@ read_backward( >> /* Do initial unaligned read if needed */ >> if ((bytes_requested = (off % io_buffersize))) { >> off -= bytes_requested; >> - bytes = do_pread(fd, off, bytes_requested, io_buffersize); >> + bytes = do_pread(fd, off, bytes_requested, io_buffersize, preadv2_flags); >> if (bytes == 0) >> return ops; >> if (bytes < 0) { >> @@ -294,7 +304,7 @@ read_backward( >> while (cnt > end) { >> bytes_requested = min(cnt, io_buffersize); >> off -= bytes_requested; >> - bytes = do_pread(fd, off, cnt, io_buffersize); >> + bytes = do_pread(fd, off, cnt, io_buffersize, preadv2_flags); >> if (bytes == 0) >> break; >> if (bytes < 0) { >> @@ -318,14 +328,15 @@ read_forward( >> long long *total, >> int verbose, >> int onlyone, >> - int eof) >> + int eof, >> + int preadv2_flags) >> { >> ssize_t bytes; >> int ops = 0; >> >> *total = 0; >> while (count > 0 || eof) { >> - bytes = do_pread(fd, offset, count, io_buffersize); >> + bytes = do_pread(fd, offset, count, io_buffersize, preadv2_flags); >> if (bytes == 0) >> break; >> if (bytes < 0) { >> @@ -353,7 +364,7 @@ read_buffer( >> int verbose, >> int onlyone) >> { >> - return read_forward(fd, offset, count, total, verbose, onlyone, 0); >> + return read_forward(fd, offset, count, total, verbose, onlyone, 0, 0); >> } >> >> static int >> @@ -371,6 +382,7 @@ pread_f( >> int Cflag, qflag, uflag, vflag; >> int eof = 0, direction = IO_FORWARD; >> int c; >> + int preadv2_flags = 0; >> >> Cflag = qflag = uflag = vflag = 0; >> init_cvtnum(&fsblocksize, &fssectsize); >> @@ -463,15 +475,18 @@ pread_f( >> case IO_RANDOM: >> if (!zeed) /* srandom seed */ >> zeed = time(NULL); >> - c = read_random(file->fd, offset, count, &total, zeed, eof); >> + c = read_random(file->fd, offset, count, &total, zeed, eof, >> + preadv2_flags); >> break; >> case IO_FORWARD: >> - c = read_forward(file->fd, offset, count, &total, vflag, 0, eof); >> + c = read_forward(file->fd, offset, count, &total, vflag, 0, eof, >> + preadv2_flags); >> if (eof) >> count = total; >> break; >> case IO_BACKWARD: >> - c = read_backward(file->fd, &offset, &count, &total, eof); >> + c = read_backward(file->fd, &offset, &count, &total, eof, >> + preadv2_flags); >> break; >> default: >> ASSERT(0); >> diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4 >> index 4ef7e8f6..5a1f748a 100644 >> --- a/m4/package_libcdev.m4 >> +++ b/m4/package_libcdev.m4 >> @@ -16,6 +16,24 @@ pwritev2(0, 0, 0, 0, 0); >> AC_SUBST(have_pwritev2) >> ]) >> >> +# >> +# Check if we have a preadv2 libc call (Linux) >> +# >> +AC_DEFUN([AC_HAVE_PREADV2], >> + [ AC_MSG_CHECKING([for preadv2]) >> + AC_LINK_IFELSE( >> + [ AC_LANG_PROGRAM([[ >> +#define _GNU_SOURCE >> +#include <sys/uio.h> >> + ]], [[ >> +preadv2(0, 0, 0, 0, 0); >> + ]]) >> + ], have_preadv2=yes >> + AC_MSG_RESULT(yes), >> + AC_MSG_RESULT(no)) >> + AC_SUBST(have_preadv2) >> + ]) >> + >> # >> # Check if we have a copy_file_range system call (Linux) >> # >> -- >> 2.48.1 >> >>
diff --git a/configure.ac b/configure.ac index 8c76f398..658117ad 100644 --- a/configure.ac +++ b/configure.ac @@ -153,6 +153,7 @@ AC_PACKAGE_NEED_URCU_H AC_PACKAGE_NEED_RCU_INIT AC_HAVE_PWRITEV2 +AC_HAVE_PREADV2 AC_HAVE_COPY_FILE_RANGE AC_NEED_INTERNAL_FSXATTR AC_NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG diff --git a/include/builddefs.in b/include/builddefs.in index 82840ec7..a11d201c 100644 --- a/include/builddefs.in +++ b/include/builddefs.in @@ -94,6 +94,7 @@ ENABLE_SCRUB = @enable_scrub@ HAVE_ZIPPED_MANPAGES = @have_zipped_manpages@ HAVE_PWRITEV2 = @have_pwritev2@ +HAVE_PREADV2 = @have_preadv2@ HAVE_COPY_FILE_RANGE = @have_copy_file_range@ NEED_INTERNAL_FSXATTR = @need_internal_fsxattr@ NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG = @need_internal_fscrypt_add_key_arg@ diff --git a/io/Makefile b/io/Makefile index 8f835ec7..f8b19ac5 100644 --- a/io/Makefile +++ b/io/Makefile @@ -69,6 +69,10 @@ ifeq ($(HAVE_PWRITEV2),yes) LCFLAGS += -DHAVE_PWRITEV2 endif +ifeq ($(HAVE_PREADV2),yes) +LCFLAGS += -DHAVE_PREADV2 +endif + ifeq ($(HAVE_MAP_SYNC),yes) LCFLAGS += -DHAVE_MAP_SYNC endif diff --git a/io/pread.c b/io/pread.c index 62c771fb..782f2a36 100644 --- a/io/pread.c +++ b/io/pread.c @@ -162,7 +162,8 @@ static ssize_t do_preadv( int fd, off_t offset, - long long count) + long long count, + int preadv2_flags) { int vecs = 0; ssize_t oldlen = 0; @@ -181,8 +182,14 @@ do_preadv( } else { vecs = vectors; } +#ifdef HAVE_PREADV2 + if (preadv2_flags) + bytes = preadv2(fd, iov, vectors, offset, preadv2_flags); + else + bytes = preadv(fd, iov, vectors, offset); +#else bytes = preadv(fd, iov, vectors, offset); - +#endif /* restore trimmed iov */ if (oldlen) iov[vecs - 1].iov_len = oldlen; @@ -195,12 +202,13 @@ do_pread( int fd, off_t offset, long long count, - size_t buffer_size) + size_t buffer_size, + int preadv2_flags) { if (!vectors) return pread(fd, io_buffer, min(count, buffer_size), offset); - return do_preadv(fd, offset, count); + return do_preadv(fd, offset, count, preadv2_flags); } static int @@ -210,7 +218,8 @@ read_random( long long count, long long *total, unsigned int seed, - int eof) + int eof, + int preadv2_flags) { off_t end, off, range; ssize_t bytes; @@ -234,7 +243,7 @@ read_random( io_buffersize; else off = offset; - bytes = do_pread(fd, off, io_buffersize, io_buffersize); + bytes = do_pread(fd, off, io_buffersize, io_buffersize, preadv2_flags); if (bytes == 0) break; if (bytes < 0) { @@ -256,7 +265,8 @@ read_backward( off_t *offset, long long *count, long long *total, - int eof) + int eof, + int preadv2_flags) { off_t end, off = *offset; ssize_t bytes = 0, bytes_requested; @@ -276,7 +286,7 @@ read_backward( /* Do initial unaligned read if needed */ if ((bytes_requested = (off % io_buffersize))) { off -= bytes_requested; - bytes = do_pread(fd, off, bytes_requested, io_buffersize); + bytes = do_pread(fd, off, bytes_requested, io_buffersize, preadv2_flags); if (bytes == 0) return ops; if (bytes < 0) { @@ -294,7 +304,7 @@ read_backward( while (cnt > end) { bytes_requested = min(cnt, io_buffersize); off -= bytes_requested; - bytes = do_pread(fd, off, cnt, io_buffersize); + bytes = do_pread(fd, off, cnt, io_buffersize, preadv2_flags); if (bytes == 0) break; if (bytes < 0) { @@ -318,14 +328,15 @@ read_forward( long long *total, int verbose, int onlyone, - int eof) + int eof, + int preadv2_flags) { ssize_t bytes; int ops = 0; *total = 0; while (count > 0 || eof) { - bytes = do_pread(fd, offset, count, io_buffersize); + bytes = do_pread(fd, offset, count, io_buffersize, preadv2_flags); if (bytes == 0) break; if (bytes < 0) { @@ -353,7 +364,7 @@ read_buffer( int verbose, int onlyone) { - return read_forward(fd, offset, count, total, verbose, onlyone, 0); + return read_forward(fd, offset, count, total, verbose, onlyone, 0, 0); } static int @@ -371,6 +382,7 @@ pread_f( int Cflag, qflag, uflag, vflag; int eof = 0, direction = IO_FORWARD; int c; + int preadv2_flags = 0; Cflag = qflag = uflag = vflag = 0; init_cvtnum(&fsblocksize, &fssectsize); @@ -463,15 +475,18 @@ pread_f( case IO_RANDOM: if (!zeed) /* srandom seed */ zeed = time(NULL); - c = read_random(file->fd, offset, count, &total, zeed, eof); + c = read_random(file->fd, offset, count, &total, zeed, eof, + preadv2_flags); break; case IO_FORWARD: - c = read_forward(file->fd, offset, count, &total, vflag, 0, eof); + c = read_forward(file->fd, offset, count, &total, vflag, 0, eof, + preadv2_flags); if (eof) count = total; break; case IO_BACKWARD: - c = read_backward(file->fd, &offset, &count, &total, eof); + c = read_backward(file->fd, &offset, &count, &total, eof, + preadv2_flags); break; default: ASSERT(0); diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4 index 4ef7e8f6..5a1f748a 100644 --- a/m4/package_libcdev.m4 +++ b/m4/package_libcdev.m4 @@ -16,6 +16,24 @@ pwritev2(0, 0, 0, 0, 0); AC_SUBST(have_pwritev2) ]) +# +# Check if we have a preadv2 libc call (Linux) +# +AC_DEFUN([AC_HAVE_PREADV2], + [ AC_MSG_CHECKING([for preadv2]) + AC_LINK_IFELSE( + [ AC_LANG_PROGRAM([[ +#define _GNU_SOURCE +#include <sys/uio.h> + ]], [[ +preadv2(0, 0, 0, 0, 0); + ]]) + ], have_preadv2=yes + AC_MSG_RESULT(yes), + AC_MSG_RESULT(no)) + AC_SUBST(have_preadv2) + ]) + # # Check if we have a copy_file_range system call (Linux) #
preadv2() was introduced in Linux 4.6. This patch adds support for preadv2() to xfs_io. Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> --- configure.ac | 1 + include/builddefs.in | 1 + io/Makefile | 4 ++++ io/pread.c | 45 ++++++++++++++++++++++++++++--------------- m4/package_libcdev.m4 | 18 +++++++++++++++++ 5 files changed, 54 insertions(+), 15 deletions(-)