From busybox Fri Nov 18 12:36:08 2022 From: Walter Harms Date: Fri, 18 Nov 2022 12:36:08 +0000 To: busybox Subject: AW: [PATCH v2 5/9] loop:refactor: extract subfunction set_loop_configure() Message-Id: X-MARC-Message: https://marc.info/?l=busybox&m=166877458113524 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; + } ________________________________________ Von: busybox im Auftrag von Xiaoming Ni Gesendet: Freitag, 18. November 2022 13:14:44 An: busybox@busybox.net; vda.linux@googlemail.com; cand@gmx.com; explorer09@gmail.com Cc: wangle6@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 --- 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 _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox