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authorDenys Vlasenko2017-03-16 16:49:37 +0100
committerDenys Vlasenko2017-03-16 16:55:47 +0100
commitab518eea9c41235a3fcde80f3ea99669eaade621 (patch)
tree4bd1783e343316fa11c2ade135dbe0b0561689a9 /include
parent018804204f41e6e60cec536843275f8fdd4d3620 (diff)
downloadbusybox-ab518eea9c41235a3fcde80f3ea99669eaade621.zip
busybox-ab518eea9c41235a3fcde80f3ea99669eaade621.tar.gz
mount: create loop devices with LO_FLAGS_AUTOCLEAR flag
The "autolooped" mount (mount [-oloop] IMAGE /DIR/DIR) always creates AUTOCLEARed loopdevs, so that umounting drops them (and this does not require any code in the umount userspace). This happens since circa linux-2.6.25: commit 96c5865559cee0f9cbc5173f3c949f6ce3525581 Date: Wed Feb 6 01:36:27 2008 -0800 Subject: Allow auto-destruction of loop devices IOW: in this case, umount does not have to use -d to drop the loopdev. The explicit loop mount (mount /dev/loopN /DIR/DIR) does not do this. In this case, umount without -d should not drop loopdev. Unfortunately, bbox umount currently always implies -d, this probably needs fixing. function old new delta set_loop 537 597 +60 singlemount 1101 1138 +37 losetup_main 419 432 +13 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 3/0 up/down: 110/0) Total: 110 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'include')
-rw-r--r--include/libbb.h11
1 files changed, 8 insertions, 3 deletions
diff --git a/include/libbb.h b/include/libbb.h
index b054e05..e97efcb 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1329,10 +1329,15 @@ extern int get_linux_version_code(void) FAST_FUNC;
extern char *query_loop(const char *device) FAST_FUNC;
extern int del_loop(const char *device) FAST_FUNC;
-/* If *devname is not NULL, use that name, otherwise try to find free one,
+/*
+ * If *devname is not NULL, use that name, otherwise try to find free one,
* malloc and return it in *devname.
- * return value: 1: read-only loopdev was setup, 0: rw, < 0: error */
-extern int set_loop(char **devname, const char *file, unsigned long long offset, int ro) FAST_FUNC;
+ * return value is the opened fd to the loop device, or < on error
+ */
+extern int set_loop(char **devname, const char *file, unsigned long long offset, unsigned flags) FAST_FUNC;
+/* These constants match linux/loop.h (without BB_ prefix): */
+#define BB_LO_FLAGS_READ_ONLY 1
+#define BB_LO_FLAGS_AUTOCLEAR 4
/* Like bb_ask below, but asks on stdin with no timeout. */
char *bb_ask_stdin(const char * prompt) FAST_FUNC;