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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2024-10-08 15:45:29 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2024-10-10 10:28:01 -0300 |
| commit | 5ffc903216901914dc2ad9715088d3fe9d1ef205 (patch) | |
| tree | ef919d5898dec5e09c3c9e2f93de73a772a19c85 | |
| parent | fc650bfd71081d26c1015d299827fb58a23a6b02 (diff) | |
| download | glibc-5ffc903216901914dc2ad9715088d3fe9d1ef205.tar.gz glibc-5ffc903216901914dc2ad9715088d3fe9d1ef205.tar.xz glibc-5ffc903216901914dc2ad9715088d3fe9d1ef205.zip | |
misc: Add support for Linux uio.h RWF_ATOMIC flag
Linux 6.11 adds the new flag for pwritev2 (commit c34fc6f26ab86d03a2d47446f42b6cd492dfdc56). Checked on x86_64-linux-gnu on 6.11 kernel. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
| -rw-r--r-- | manual/llio.texi | 13 | ||||
| -rw-r--r-- | misc/tst-preadvwritev2-common.c | 5 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/bits/uio-ext.h | 2 |
3 files changed, 19 insertions, 1 deletions
diff --git a/manual/llio.texi b/manual/llio.texi index 05ab44c6e7..0eb336f70b 100644 --- a/manual/llio.texi +++ b/manual/llio.texi @@ -1381,6 +1381,19 @@ Per-IO synchronization as if the file was opened with @code{O_APPEND} flag. @item RWF_NOAPPEND This flag allows an offset to be honored, even if the file was opened with @code{O_APPEND} flag. + +@item RWF_ATOMIC +Indicate that the write is to be issued with torn-write prevention. The +input buffer should follow some contraints: the total length should be +power-of-2 in size and also sizes between @code{atomic_write_unit_min} +and @code{atomic_write_unit_max}, the @code{struct iovec} count should be +up to @code{atomic_write_segments_max}, and the offset should be +naturally-aligned with regard to total write length. + +The @code{atomic_*} values can be obtained with @code{statx} along with +@code{STATX_WRITE_ATOMIC} flag. + +This is a Linux-specific extension. @end vtable When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the diff --git a/misc/tst-preadvwritev2-common.c b/misc/tst-preadvwritev2-common.c index 8e04ff7282..4556421a43 100644 --- a/misc/tst-preadvwritev2-common.c +++ b/misc/tst-preadvwritev2-common.c @@ -37,8 +37,11 @@ #ifndef RWF_NOAPPEND # define RWF_NOAPPEND 0 #endif +#ifndef RWF_ATOMIC +# define RWF_ATOMIC 0 +#endif #define RWF_SUPPORTED (RWF_HIPRI | RWF_DSYNC | RWF_SYNC | RWF_NOWAIT \ - | RWF_APPEND | RWF_NOAPPEND) + | RWF_APPEND | RWF_NOAPPEND | RWF_ATOMIC) /* Generic uio_lim.h does not define IOV_MAX. */ #ifndef IOV_MAX diff --git a/sysdeps/unix/sysv/linux/bits/uio-ext.h b/sysdeps/unix/sysv/linux/bits/uio-ext.h index ead7a09156..85ed21bac5 100644 --- a/sysdeps/unix/sysv/linux/bits/uio-ext.h +++ b/sysdeps/unix/sysv/linux/bits/uio-ext.h @@ -48,6 +48,8 @@ extern ssize_t process_vm_writev (pid_t __pid, const struct iovec *__lvec, #define RWF_NOWAIT 0x00000008 /* per-IO nonblocking mode. */ #define RWF_APPEND 0x00000010 /* per-IO O_APPEND. */ #define RWF_NOAPPEND 0x00000020 /* per-IO negation of O_APPEND */ +#define RWF_ATOMIC 0x00000040 /* Write is to be issued with torn-write + prevention. */ __END_DECLS |