8:10 a.m.
this is in preparation for a minor refactoring of the copy
function itself out of runIO().
Signed-off-by: Claudio Fontana <cfontana(a)suse.de>
Reviewed-by: Daniel P. Berrangé <berrange(a)redhat.com>
---
src/util/iohelper.c | 95 +++++++++++++++++++++++++--------------------
1 file changed, 53 insertions(+), 42 deletions(-)
diff --git a/src/util/iohelper.c b/src/util/iohelper.c
index 2c91bf4f93..c13746a547 100644
--- a/src/util/iohelper.c
+++ b/src/util/iohelper.c
@@ -45,6 +45,16 @@
# define O_DIRECT 0
#endif
+struct runIOParams {
+ bool isBlockDev;
+ bool isDirect;
+ bool isWrite;
+ int fdin;
+ const char *fdinname;
+ int fdout;
+ const char *fdoutname;
+};
+
static int
runIO(const char *path, int fd, int oflags)
{
@@ -53,13 +63,9 @@ runIO(const char *path, int fd, int oflags)
size_t buflen = 1024*1024;
intptr_t alignMask = 64*1024 - 1;
int ret = -1;
- int fdin, fdout;
- const char *fdinname, *fdoutname;
- unsigned long long total = 0;
- bool direct = O_DIRECT && ((oflags & O_DIRECT) != 0);
- off_t end = 0;
+ off_t total = 0;
struct stat sb;
- bool isBlockDev = false;
+ struct runIOParams p;
#if WITH_POSIX_MEMALIGN
if (posix_memalign(&base, alignMask + 1, buflen))
@@ -77,34 +83,23 @@ runIO(const char *path, int fd, int oflags)
fd, path);
goto cleanup;
}
- isBlockDev = S_ISBLK(sb.st_mode);
+ p.isBlockDev = S_ISBLK(sb.st_mode);
+ p.isDirect = O_DIRECT && (oflags & O_DIRECT);
switch (oflags & O_ACCMODE) {
case O_RDONLY:
- fdin = fd;
- fdinname = path;
- fdout = STDOUT_FILENO;
- fdoutname = "stdout";
- /* To make the implementation simpler, we give up on any
- * attempt to use O_DIRECT in a non-trivial manner. */
- if (!isBlockDev && direct && ((end = lseek(fd, 0, SEEK_CUR)) !=
0)) {
- virReportSystemError(end < 0 ? errno : EINVAL, "%s",
- _("O_DIRECT read needs entire seekable
file"));
- goto cleanup;
- }
+ p.isWrite = false;
+ p.fdin = fd;
+ p.fdinname = path;
+ p.fdout = STDOUT_FILENO;
+ p.fdoutname = "stdout";
break;
case O_WRONLY:
- fdin = STDIN_FILENO;
- fdinname = "stdin";
- fdout = fd;
- fdoutname = path;
- /* To make the implementation simpler, we give up on any
- * attempt to use O_DIRECT in a non-trivial manner. */
- if (!isBlockDev && direct && (end = lseek(fd, 0, SEEK_END)) != 0)
{
- virReportSystemError(end < 0 ? errno : EINVAL, "%s",
- _("O_DIRECT write needs empty seekable
file"));
- goto cleanup;
- }
+ p.isWrite = true;
+ p.fdin = STDIN_FILENO;
+ p.fdinname = "stdin";
+ p.fdout = fd;
+ p.fdoutname = path;
break;
case O_RDWR:
@@ -114,6 +109,22 @@ runIO(const char *path, int fd, int oflags)
(oflags & O_ACCMODE));
goto cleanup;
}
+ /* To make the implementation simpler, we give up on any
+ * attempt to use O_DIRECT in a non-trivial manner. */
+ if (!p.isBlockDev && p.isDirect) {
+ off_t off;
+ if (p.isWrite) {
+ if ((off = lseek(fd, 0, SEEK_END)) != 0) {
+ virReportSystemError(off < 0 ? errno : EINVAL, "%s",
+ _("O_DIRECT write needs empty seekable
file"));
+ goto cleanup;
+ }
+ } else if ((off = lseek(fd, 0, SEEK_CUR)) != 0) {
+ virReportSystemError(off < 0 ? errno : EINVAL, "%s",
+ _("O_DIRECT read needs entire seekable
file"));
+ goto cleanup;
+ }
+ }
while (1) {
ssize_t got;
@@ -124,16 +135,16 @@ runIO(const char *path, int fd, int oflags)
* writes will be aligned.
* In other cases using saferead reduces number of syscalls.
*/
- if (fdin == fd && direct) {
- if ((got = read(fdin, buf, buflen)) < 0 &&
+ if (!p.isWrite && p.isDirect) {
+ if ((got = read(p.fdin, buf, buflen)) < 0 &&
errno == EINTR)
continue;
} else {
- got = saferead(fdin, buf, buflen);
+ got = saferead(p.fdin, buf, buflen);
}
if (got < 0) {
- virReportSystemError(errno, _("Unable to read %s"), fdinname);
+ virReportSystemError(errno, _("Unable to read %s"), p.fdinname);
goto cleanup;
}
if (got == 0)
@@ -142,35 +153,35 @@ runIO(const char *path, int fd, int oflags)
total += got;
/* handle last write size align in direct case */
- if (got < buflen && direct && fdout == fd) {
+ if (got < buflen && p.isDirect && p.isWrite) {
ssize_t aligned_got = (got + alignMask) & ~alignMask;
memset(buf + got, 0, aligned_got - got);
- if (safewrite(fdout, buf, aligned_got) < 0) {
- virReportSystemError(errno, _("Unable to write %s"),
fdoutname);
+ if (safewrite(p.fdout, buf, aligned_got) < 0) {
+ virReportSystemError(errno, _("Unable to write %s"),
p.fdoutname);
goto cleanup;
}
- if (!isBlockDev && ftruncate(fd, total) < 0) {
- virReportSystemError(errno, _("Unable to truncate %s"),
fdoutname);
+ if (!p.isBlockDev && ftruncate(p.fdout, total) < 0) {
+ virReportSystemError(errno, _("Unable to truncate %s"),
p.fdoutname);
goto cleanup;
}
break;
}
- if (safewrite(fdout, buf, got) < 0) {
- virReportSystemError(errno, _("Unable to write %s"), fdoutname);
+ if (safewrite(p.fdout, buf, got) < 0) {
+ virReportSystemError(errno, _("Unable to write %s"), p.fdoutname);
goto cleanup;
}
}
/* Ensure all data is written */
- if (virFileDataSync(fdout) < 0) {
+ if (virFileDataSync(p.fdout) < 0) {
if (errno != EINVAL && errno != EROFS) {
/* fdatasync() may fail on some special FDs, e.g. pipes */
- virReportSystemError(errno, _("unable to fsync %s"), fdoutname);
+ virReportSystemError(errno, _("unable to fsync %s"), p.fdoutname);
goto cleanup;
}
}
--
2.35.3