Step 4 of micro-refactoring the set_loop(): Extract subfunction set_loop_info() from set_loop()
function old new delta set_loop 734 700 -34 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-34) Total: -34 bytes Signed-off-by: Xiaoming Ni <nixiaom...@huawei.com> --- libbb/loop.c | 91 +++++++++++++++++++++++++++------------------------- 1 file changed, 47 insertions(+), 44 deletions(-) diff --git a/libbb/loop.c b/libbb/loop.c index 91c3a45c4..89adc4f94 100644 --- a/libbb/loop.c +++ b/libbb/loop.c @@ -126,6 +126,47 @@ static int open_file(const char *file, unsigned flags, int *mode) return ffd; } +static int set_loop_info(int ffd, int lfd, const char *file, + unsigned long long offset, unsigned long long sizelimit, unsigned flags) +{ + int rc; + bb_loop_info loopinfo; + + rc = ioctl(lfd, BB_LOOP_GET_STATUS, &loopinfo); + + /* 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 -1; +} + /* Returns opened fd to the loop device, <0 on error. * *device is loop device to use, or if *device==NULL finds a loop device to * mount it on and sets *device to a strdup of that loop device name. @@ -135,7 +176,6 @@ int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offse { char dev[LOOP_NAMESIZE]; char *try; - bb_loop_info loopinfo; struct stat statbuf; int i, lfd, ffd, mode, rc; @@ -190,49 +230,12 @@ int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offse } goto try_next_loopN; } - - rc = ioctl(lfd, BB_LOOP_GET_STATUS, &loopinfo); - - /* 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)) { - close(lfd); - /* Ouch. Are we racing with other mount? */ - if (!*device) { -//TODO: add "if (--failcount != 0) ..."? - continue; - } else { - break; - } - } - 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) { - /* SUCCESS! */ - if (!*device) /* was looping in search of free "/dev/loopN"? */ - *device = xstrdup(dev); - rc = lfd; /* return this */ - break; - } - /* failure, undo LOOP_SET_FD */ - ioctl(lfd, LOOP_CLR_FD, 0); // actually, 0 param is unnecessary + rc = set_loop_info(ffd, lfd, file, offset, sizelimit, flags); + if (rc == lfd) { + /* SUCCESS! */ + if (!*device) + *device = xstrdup(dev); + break; } close(lfd); try_next_loopN: -- 2.27.0 _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox