diff options
Diffstat (limited to 'lib/loopdev.c')
| -rw-r--r-- | lib/loopdev.c | 57 |
1 files changed, 43 insertions, 14 deletions
diff --git a/lib/loopdev.c b/lib/loopdev.c index 5ef439440..7ba425e7c 100644 --- a/lib/loopdev.c +++ b/lib/loopdev.c @@ -1601,6 +1601,45 @@ int loopcxt_ioctl_blocksize(struct loopdev_cxt *lc, uint64_t blocksize) return 0; } +/* + * @lc: context + * @nr: returns loop device number + * + * Extracts the loop device number from the device path. + * Supports both /dev/loop<N> and /dev/loop/<N> formats. + * + * Returns: 0 on success, <0 on error + */ +static int loopcxt_get_device_nr(struct loopdev_cxt *lc, int *nr) +{ + const char *p, *dev; + int rc = -EINVAL; + + errno = 0; + if (!lc || !nr) + goto done; + + dev = loopcxt_get_device(lc); + if (!dev) + goto done; + + p = strrchr(dev, '/'); + if (!p) + goto done; + + if (sscanf(p, "/loop%d", nr) != 1 && sscanf(p, "/%d", nr) != 1) + goto done; + + if (*nr < 0) + goto done; + rc = 0; +done: + if (rc && !errno) + errno = -rc; + DBG(CXT, ul_debugobj(lc, "get_device_nr [nr=%d]", *nr)); + return rc; +} + int loopcxt_detach_device(struct loopdev_cxt *lc) { int rc, fd = loopcxt_get_fd(lc); @@ -1624,19 +1663,14 @@ int loopcxt_remove_device(struct loopdev_cxt *lc) { int rc = -EINVAL; int ctl, nr = -1; - const char *p, *dev = loopcxt_get_device(lc); - - if (!dev) - goto done; if (!(lc->flags & LOOPDEV_FL_CONTROL)) { rc = -ENOSYS; goto done; } - p = strrchr(dev, '/'); - if (!p || (sscanf(p, "/loop%d", &nr) != 1 && sscanf(p, "/%d", &nr) != 1) - || nr < 0) + rc = loopcxt_get_device_nr(lc, &nr); + if (rc) goto done; ctl = open(_PATH_DEV_LOOPCTL, O_RDWR|O_CLOEXEC); @@ -1655,19 +1689,14 @@ int loopcxt_add_device(struct loopdev_cxt *lc) { int rc = -EINVAL; int ctl, nr = -1; - const char *p, *dev = loopcxt_get_device(lc); - - if (!dev) - goto done; if (!(lc->flags & LOOPDEV_FL_CONTROL)) { rc = -ENOSYS; goto done; } - p = strrchr(dev, '/'); - if (!p || (sscanf(p, "/loop%d", &nr) != 1 && sscanf(p, "/%d", &nr) != 1) - || nr < 0) + rc = loopcxt_get_device_nr(lc, &nr); + if (rc) goto done; ctl = open(_PATH_DEV_LOOPCTL, O_RDWR|O_CLOEXEC); |