path: root/discover/udev.c
diff options
authorJeremy Kerr <>2014-03-13 10:07:12 +0800
committerJeremy Kerr <>2014-03-14 15:14:47 +0800
commit43f340b66d8323c6e797868d07fc98482052ba35 (patch)
tree5a7b93384aa112a7e9a15b6ee55c0f3f0d29e8a6 /discover/udev.c
parentbb3ddd63720501f451d3f2797f315c25efd3bd4a (diff)
discover: Use ID_FS_TYPE property for filesystem type detection
Currently, we don't hand any -t option to mount, as we expect the mount binary to do autodetection of the filesystem type for us. Turns out this isn't great with busybox mount, (which we're likely to be using in petitboot builds), which implements "autodetection" by trying the mount() syscall with every fs type in /proc/filesystems, until one succeeds. We expect a lot of the mount calls to fail, as we currently try to mount everything (and abort discovery on devices that don't mount), including non-filesystem partitions. On a test machine with 560 block devices, and 37 entries in /proc/partitions, this results in around 20,000 calls to mount(). A better way would be to pass a -t option to mount. It turns out that udev uses libblkid to probe the filesystem type, which is available in the ID_FS_TYPE property. This change only attempts to mount filesystems with this property, and passes an explicit fstype to the mount binary. Signed-off-by: Jeremy Kerr <>
Diffstat (limited to 'discover/udev.c')
1 files changed, 6 insertions, 0 deletions
diff --git a/discover/udev.c b/discover/udev.c
index 0b2ec2f..7a99eea 100644
--- a/discover/udev.c
+++ b/discover/udev.c
@@ -69,6 +69,7 @@ static int udev_handle_block_add(struct pb_udev *udev, struct udev_device *dev,
const char *path;
const char *node;
const char *prop;
+ const char *type;
bool cdrom;
typestr = udev_device_get_devtype(dev);
@@ -101,6 +102,11 @@ static int udev_handle_block_add(struct pb_udev *udev, struct udev_device *dev,
+ type = udev_device_get_property_value(dev, "ID_FS_TYPE");
+ if (!type) {
+ pb_debug("SKIP: %s: no ID_FS_TYPE property\n", name);
+ return 0;
+ }
/* We may see multipath devices; they'll have the same uuid as an
* existing device, so only parse the first. */
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