Hi Kay, On Thu, 19 Jul 2007 02:44:54 +0200, Kay Sievers wrote: > On 7/18/07, Jean Delvare <[EMAIL PROTECTED]> wrote: > > On Tue, 17 Jul 2007 20:38:28 -0700, Greg KH wrote: > > > On Tue, Jul 17, 2007 at 11:05:30PM +0200, Jean Delvare wrote: > > > > The code looks like: > > > > > > > > if (sysfs_get_mnt_path(sensors_sysfs_mount, NAME_MAX) > > > > || stat(sensors_sysfs_mount, &statbuf) < 0 > > > > || statbuf.st_nlink <= 2) /* Empty directory */ > > > > return 0; /* Failure */ > > > > > > > > This works OK with 2.6.22.1, but the last test fails with the current > > > > git kernel even when sysfs is mounted. > > > > > > Yeah, but is checking the number of hard links in the directory a safe > > > way to always verify that it isn't empty? > > > > I think so, yes. To the best of my knowledge, it has worked on all > > Unix-like systems for decades. There are other ways, but this is by far > > the less expensive. > > Well, just check if /sys/devices/ exists, that should be cheap enough. :)
Yes, this is a possibility, and one I had considered at first. But I wasn't sure which subdirectory to check. sysfs isn't well known for its stability, and I didn't know which directories exist since the early days of sysfs, and which do not. For example, fs, kernel and module were not present in 2.6.5. I am also not sure if directories which exist today are guaranteed to exist forever. This is the reason why I decided to check the link count instead, basically checking that at least one subdirectory exists, without having to name it. -- Jean Delvare - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
