Signed-off-by: Claudio Fontana <cfont...@suse.de> Reviewed-by: Daniel P. Berrangé <berra...@redhat.com> --- src/util/iohelper.c | 131 +++++++++++++++++++++++++------------------- 1 file changed, 75 insertions(+), 56 deletions(-)
diff --git a/src/util/iohelper.c b/src/util/iohelper.c index c13746a547..1584321839 100644 --- a/src/util/iohelper.c +++ b/src/util/iohelper.c @@ -55,17 +55,23 @@ struct runIOParams { const char *fdoutname; }; -static int -runIO(const char *path, int fd, int oflags) +/** + * runIOCopy: execute the IO copy based on the passed parameters + * @p: the IO parameters + * + * Execute the copy based on the passed parameters. + * + * Returns: size transfered, or < 0 on error. + */ + +static off_t +runIOCopy(const struct runIOParams p) { g_autofree void *base = NULL; /* Location to be freed */ char *buf = NULL; /* Aligned location within base */ size_t buflen = 1024*1024; intptr_t alignMask = 64*1024 - 1; - int ret = -1; off_t total = 0; - struct stat sb; - struct runIOParams p; #if WITH_POSIX_MEMALIGN if (posix_memalign(&base, alignMask + 1, buflen)) @@ -77,6 +83,67 @@ runIO(const char *path, int fd, int oflags) buf = (char *) (((intptr_t) base + alignMask) & ~alignMask); #endif + while (1) { + ssize_t got; + + /* If we read with O_DIRECT from file we can't use saferead as + * it can lead to unaligned read after reading last bytes. + * If we write with O_DIRECT use should use saferead so that + * writes will be aligned. + * In other cases using saferead reduces number of syscalls. + */ + if (!p.isWrite && p.isDirect) { + if ((got = read(p.fdin, buf, buflen)) < 0 && + errno == EINTR) + continue; + } else { + got = saferead(p.fdin, buf, buflen); + } + + if (got < 0) { + virReportSystemError(errno, _("Unable to read %s"), p.fdinname); + return -2; + } + if (got == 0) + break; + + total += got; + + /* handle last write size align in direct case */ + if (got < buflen && p.isDirect && p.isWrite) { + ssize_t aligned_got = (got + alignMask) & ~alignMask; + + memset(buf + got, 0, aligned_got - got); + + if (safewrite(p.fdout, buf, aligned_got) < 0) { + virReportSystemError(errno, _("Unable to write %s"), p.fdoutname); + return -3; + } + + if (!p.isBlockDev && ftruncate(p.fdout, total) < 0) { + virReportSystemError(errno, _("Unable to truncate %s"), p.fdoutname); + return -4; + } + + break; + } + + if (safewrite(p.fdout, buf, got) < 0) { + virReportSystemError(errno, _("Unable to write %s"), p.fdoutname); + return -3; + } + } + return total; +} + +static int +runIO(const char *path, int fd, int oflags) +{ + int ret = -1; + off_t total = 0; + struct stat sb; + struct runIOParams p; + if (fstat(fd, &sb) < 0) { virReportSystemError(errno, _("Unable to access file descriptor %d path %s"), @@ -125,57 +192,9 @@ runIO(const char *path, int fd, int oflags) goto cleanup; } } - - while (1) { - ssize_t got; - - /* If we read with O_DIRECT from file we can't use saferead as - * it can lead to unaligned read after reading last bytes. - * If we write with O_DIRECT use should use saferead so that - * writes will be aligned. - * In other cases using saferead reduces number of syscalls. - */ - if (!p.isWrite && p.isDirect) { - if ((got = read(p.fdin, buf, buflen)) < 0 && - errno == EINTR) - continue; - } else { - got = saferead(p.fdin, buf, buflen); - } - - if (got < 0) { - virReportSystemError(errno, _("Unable to read %s"), p.fdinname); - goto cleanup; - } - if (got == 0) - break; - - total += got; - - /* handle last write size align in direct case */ - if (got < buflen && p.isDirect && p.isWrite) { - ssize_t aligned_got = (got + alignMask) & ~alignMask; - - memset(buf + got, 0, aligned_got - got); - - if (safewrite(p.fdout, buf, aligned_got) < 0) { - virReportSystemError(errno, _("Unable to write %s"), p.fdoutname); - goto cleanup; - } - - if (!p.isBlockDev && ftruncate(p.fdout, total) < 0) { - virReportSystemError(errno, _("Unable to truncate %s"), p.fdoutname); - goto cleanup; - } - - break; - } - - if (safewrite(p.fdout, buf, got) < 0) { - virReportSystemError(errno, _("Unable to write %s"), p.fdoutname); - goto cleanup; - } - } + total = runIOCopy(p); + if (total < 0) + goto cleanup; /* Ensure all data is written */ if (virFileDataSync(p.fdout) < 0) { -- 2.35.3