On 2022/11/18 20:36, Walter Harms wrote:
A little tweak make it more readable (i hope)
putting if (rc) direkt behind
rc = ioctl(lfd, BB_LOOP_SET_STATUS, &loopinfo);
if (rc == 0)
return lfd;
// no need to check rc again
if ( (loopinfo.lo_flags & BB_LO_FLAGS_AUTOCLEAR)) {
// try again without BB_LO_FLAGS_AUTOCLEAR
// does it realy work that way ? no ~ ?
loopinfo.lo_flags -= BB_LO_FLAGS_AUTOCLEAR;
rc = ioctl(lfd, BB_LOOP_SET_STATUS, &loopinfo);
}
if (rc == 0)
return lfd;
+ rc = ioctl(lfd, BB_LOOP_SET_STATUS, &loopinfo);
+ if (rc != 0 && (loopinfo.lo_flags & BB_LO_FLAGS_AUTOCLEAR)) {
+ /* Old kernel, does not support LO_FLAGS_AUTOCLEAR? */
+ /* (this code path is not tested) */
+ loopinfo.lo_flags -= BB_LO_FLAGS_AUTOCLEAR;
+ rc = ioctl(lfd, BB_LOOP_SET_STATUS, &loopinfo);
+ }
+ if (rc == 0) {
+ return lfd;
+ }
In this case, duplicate "if(rc==0)" occurs.
Is that worse?
Thanks
Xiaoming Ni
________________________________________
Von: busybox <busybox-boun...@busybox.net> im Auftrag von Xiaoming Ni
<nixiaom...@huawei.com>
Gesendet: Freitag, 18. November 2022 13:14:44
An: busybox@busybox.net; vda.li...@googlemail.com; c...@gmx.com;
explore...@gmail.com
Cc: wang...@huawei.com
Betreff: [PATCH v2 5/9] loop:refactor: extract subfunction set_loop_configure()
Step 5 of micro-refactoring the set_loop():
Extract subfunction set_loop_configure()
function old new delta
set_loop 700 708 +8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 8/0) Total: 8 bytes
Signed-off-by: Xiaoming Ni <nixiaom...@huawei.com>
---
libbb/loop.c | 63 ++++++++++++++++++++++++++++++----------------------
1 file changed, 36 insertions(+), 27 deletions(-)
diff --git a/libbb/loop.c b/libbb/loop.c
index 89adc4f94..914af57b2 100644
--- a/libbb/loop.c
+++ b/libbb/loop.c
@@ -126,6 +126,41 @@ static int open_file(const char *file, unsigned flags, int
*mode)
return ffd;
}
+static int set_loop_configure(int ffd, int lfd, const char *file,
+ unsigned long long offset, unsigned long long sizelimit,
unsigned flags)
+{
+ int rc;
+ bb_loop_info loopinfo;
+ /* Associate free loop device with file */
+ if (ioctl(lfd, LOOP_SET_FD, ffd)) {
+ return -1;
+ }
+ memset(&loopinfo, 0, sizeof(loopinfo));
+ safe_strncpy((char *)loopinfo.lo_file_name, file, LO_NAME_SIZE);
+ loopinfo.lo_offset = offset;
+ loopinfo.lo_sizelimit = sizelimit;
+ /*
+ * Used by mount to set LO_FLAGS_AUTOCLEAR.
+ * LO_FLAGS_READ_ONLY is not set because RO is controlled by open type
of the file.
+ * Note that closing LO_FLAGS_AUTOCLEARed lfd before mount
+ * is wrong (would free the loop device!)
+ */
+ loopinfo.lo_flags = (flags & ~BB_LO_FLAGS_READ_ONLY);
+ rc = ioctl(lfd, BB_LOOP_SET_STATUS, &loopinfo);
+ if (rc != 0 && (loopinfo.lo_flags & BB_LO_FLAGS_AUTOCLEAR)) {
+ /* Old kernel, does not support LO_FLAGS_AUTOCLEAR? */
+ /* (this code path is not tested) */
+ loopinfo.lo_flags -= BB_LO_FLAGS_AUTOCLEAR;
+ rc = ioctl(lfd, BB_LOOP_SET_STATUS, &loopinfo);
+ }
+ if (rc == 0) {
+ return lfd;
+ }
+ /* failure, undo LOOP_SET_FD */
+ ioctl(lfd, LOOP_CLR_FD, 0); // actually, 0 param is unnecessary
+ return -1;
+}
+
static int set_loop_info(int ffd, int lfd, const char *file,
unsigned long long offset, unsigned long long sizelimit,
unsigned flags)
{
@@ -136,33 +171,7 @@ static int set_loop_info(int ffd, int lfd, const char
*file,
/* If device is free, try to claim it */
if (rc && errno == ENXIO) {
- /* Associate free loop device with file */
- if (ioctl(lfd, LOOP_SET_FD, ffd)) {
- return -1;
- }
- memset(&loopinfo, 0, sizeof(loopinfo));
- safe_strncpy((char *)loopinfo.lo_file_name, file, LO_NAME_SIZE);
- loopinfo.lo_offset = offset;
- loopinfo.lo_sizelimit = sizelimit;
- /*
- * Used by mount to set LO_FLAGS_AUTOCLEAR.
- * LO_FLAGS_READ_ONLY is not set because RO is controlled by
open type of the file.
- * Note that closing LO_FLAGS_AUTOCLEARed lfd before mount
- * is wrong (would free the loop device!)
- */
- loopinfo.lo_flags = (flags & ~BB_LO_FLAGS_READ_ONLY);
- rc = ioctl(lfd, BB_LOOP_SET_STATUS, &loopinfo);
- if (rc != 0 && (loopinfo.lo_flags & BB_LO_FLAGS_AUTOCLEAR)) {
- /* Old kernel, does not support LO_FLAGS_AUTOCLEAR? */
- /* (this code path is not tested) */
- loopinfo.lo_flags -= BB_LO_FLAGS_AUTOCLEAR;
- rc = ioctl(lfd, BB_LOOP_SET_STATUS, &loopinfo);
- }
- if (rc == 0) {
- return lfd;
- }
- /* failure, undo LOOP_SET_FD */
- ioctl(lfd, LOOP_CLR_FD, 0); // actually, 0 param is unnecessary
+ return set_loop_configure(ffd, lfd, file, offset, sizelimit,
flags);
}
return -1;
}
--
2.27.0
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