- don't free user-supplied string (via -e)

[oweals/busybox.git] / libbb / loop.c

diff --git a/libbb/loop.c b/libbb/loop.c
index da41d1e765a10f58ff05c0cad222bec1f5b47781..7d2b420be13123c113b155c1962f2a0c68fd81cf 100644 (file)
--- a/libbb/loop.c
+++ b/libbb/loop.c
@@ -44,15 +44,16 @@ typedef struct {
 } bb_loop_info;
 #endif
 
-char *query_loop(const char *device)
+char* FAST_FUNC query_loop(const char *device)
 {
        int fd;
        bb_loop_info loopinfo;
-       char *dev=0;
+       char *dev = 0;
 
-       if ((fd = open(device, O_RDONLY)) < 0) return 0;
+       fd = open(device, O_RDONLY);
+       if (fd < 0) return 0;
        if (!ioctl(fd, BB_LOOP_GET_STATUS, &loopinfo))
-               dev=xasprintf("%ld %s", (long) loopinfo.lo_offset,
+               dev = xasprintf("%ld %s", (long) loopinfo.lo_offset,
                                (char *)loopinfo.lo_file_name);
        close(fd);
 
@@ -60,12 +61,13 @@ char *query_loop(const char *device)
 }
 
 
-int del_loop(const char *device)
+int FAST_FUNC del_loop(const char *device)
 {
        int fd, rc;
 
-       if ((fd = open(device, O_RDONLY)) < 0) return 1;
-       rc=ioctl(fd, LOOP_CLR_FD, 0);
+       fd = open(device, O_RDONLY);
+       if (fd < 0) return 1;
+       rc = ioctl(fd, LOOP_CLR_FD, 0);
        close(fd);
 
        return rc;
@@ -77,43 +79,56 @@ int del_loop(const char *device)
    search will re-use an existing loop device already bound to that
    file/offset if it finds one.
  */
-int set_loop(char **device, const char *file, int offset)
+int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offset)
 {
-       char dev[20], *try;
+       char dev[LOOP_NAMESIZE];
+       char *try;
        bb_loop_info loopinfo;
        struct stat statbuf;
-       int i, dfd, ffd, mode, rc=-1;
-       
+       int i, dfd, ffd, mode, rc = -1;
+
        /* Open the file.  Barf if this doesn't work.  */
-       if((ffd = open(file, mode=O_RDWR))<0 && (ffd = open(file,mode=O_RDONLY))<0)
-               return -errno;
+       mode = O_RDWR;
+       ffd = open(file, mode);
+       if (ffd < 0) {
+               mode = O_RDONLY;
+               ffd = open(file, mode);
+               if (ffd < 0)
+                       return -errno;
+       }
 
        /* Find a loop device.  */
-       try=*device ? : dev;
-       for(i=0;rc;i++) {
+       try = *device ? : dev;
+       for (i = 0; rc; i++) {
                sprintf(dev, LOOP_FORMAT, i);
 
                /* Ran out of block devices, return failure.  */
-               if(stat(try, &statbuf) || !S_ISBLK(statbuf.st_mode)) {
-                       rc=-ENOENT;
+               if (stat(try, &statbuf) || !S_ISBLK(statbuf.st_mode)) {
+                       rc = -ENOENT;
                        break;
                }
                /* Open the sucker and check its loopiness.  */
-               if((dfd=open(try, mode))<0 && errno==EROFS)
-                       dfd=open(try, mode = O_RDONLY);
-               if(dfd<0) goto try_again;
+               dfd = open(try, mode);
+               if (dfd < 0 && errno == EROFS) {
+                       mode = O_RDONLY;
+                       dfd = open(try, mode);
+               }
+               if (dfd < 0)
+                       goto try_again;
 
-               rc=ioctl(dfd, BB_LOOP_GET_STATUS, &loopinfo);
+               rc = ioctl(dfd, BB_LOOP_GET_STATUS, &loopinfo);
 
-               /* If device free, claim it.  */
-               if(rc && errno==ENXIO) {
+               /* If device is free, claim it.  */
+               if (rc && errno == ENXIO) {
                        memset(&loopinfo, 0, sizeof(loopinfo));
                        safe_strncpy((char *)loopinfo.lo_file_name, file, LO_NAME_SIZE);
                        loopinfo.lo_offset = offset;
                        /* Associate free loop device with file.  */
-                       if(!ioctl(dfd, LOOP_SET_FD, ffd)) {
-                               if (!ioctl(dfd, BB_LOOP_SET_STATUS, &loopinfo)) rc=0;
-                               else ioctl(dfd, LOOP_CLR_FD, 0);
+                       if (!ioctl(dfd, LOOP_SET_FD, ffd)) {
+                               if (!ioctl(dfd, BB_LOOP_SET_STATUS, &loopinfo))
+                                       rc = 0;
+                               else
+                                       ioctl(dfd, LOOP_CLR_FD, 0);
                        }
 
                /* If this block device already set up right, re-use it.
@@ -121,15 +136,19 @@ int set_loop(char **device, const char *file, int offset)
                   file isn't pretty either.  In general, mounting the same file twice
                   without using losetup manually is problematic.)
                 */
-               } else if(strcmp(file,(char *)loopinfo.lo_file_name)
-                                       || offset!=loopinfo.lo_offset) rc=-1;
+               } else if (strcmp(file, (char *)loopinfo.lo_file_name) != 0
+               || offset != loopinfo.lo_offset) {
+                       rc = -1;
+               }
                close(dfd);
-try_again:
-               if(*device) break;
+ try_again:
+               if (*device) break;
        }
        close(ffd);
-       if(!rc) {
-               if(!*device) *device=strdup(dev);
-               return mode==O_RDONLY ? 1 : 0;
-       } else return rc;
+       if (!rc) {
+               if (!*device)
+                       *device = xstrdup(dev);
+               return (mode == O_RDONLY); /* 1:ro, 0:rw */
+       }
+       return rc;
 }