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-rw-r--r--libbb/loop.c90
1 files changed, 51 insertions, 39 deletions
diff --git a/libbb/loop.c b/libbb/loop.c
index 256b7ac..424c392 100644
--- a/libbb/loop.c
+++ b/libbb/loop.c
@@ -110,6 +110,51 @@ static int get_next_free_loop(char *dev, int id)
return loopdevno;
}
+static int set_loopdev_params(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 */
+ rc = ioctl(lfd, LOOP_SET_FD, ffd);
+ if (rc != 0) {
+ /* Ouch... race: the device already has a fd */
+ 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 rc; /* SUCCESS! */
+ /* 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.
@@ -119,7 +164,6 @@ 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;
@@ -183,45 +227,13 @@ 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 */
- rc = ioctl(lfd, LOOP_SET_FD, ffd);
- if (rc != 0) {
- /* Ouch... race: the device already has a fd */
- goto close_and_try_next_loopN;
- }
- 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_loopdev_params(ffd, lfd, file, offset, sizelimit, flags);
+ if (rc == 0) {
+ /* SUCCESS! */
+ if (!*device)
+ *device = xstrdup(dev);
+ break;
}
- close_and_try_next_loopN:
close(lfd);
try_next_loopN:
rc = -1;