diff options
Diffstat (limited to 'Documentation/sysfs-rules.txt')
| -rw-r--r-- | Documentation/sysfs-rules.txt | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/Documentation/sysfs-rules.txt b/Documentation/sysfs-rules.txt index 80ef562160b..a5f985ee182 100644 --- a/Documentation/sysfs-rules.txt +++ b/Documentation/sysfs-rules.txt @@ -3,9 +3,8 @@ Rules on how to access information in the Linux kernel sysfs The kernel-exported sysfs exports internal kernel implementation details and depends on internal kernel structures and layout. It is agreed upon by the kernel developers that the Linux kernel does not provide a stable -internal API. As sysfs is a direct export of kernel internal -structures, the sysfs interface cannot provide a stable interface either; -it may always change along with internal kernel changes. +internal API. Therefore, there are aspects of the sysfs interface that +may not be stable across kernel releases. To minimize the risk of breaking users of sysfs, which are in most cases low-level userspace applications, with a new kernel release, the users @@ -48,7 +47,7 @@ versions of the sysfs interface. at device creation and removal - the unique key to the device at that point in time - the kernel's path to the device directory without the leading - /sys, and always starting with with a slash + /sys, and always starting with a slash - all elements of a devpath must be real directories. Symlinks pointing to /sys/devices must always be resolved to their real target and the target path must be used to access the device. @@ -114,7 +113,7 @@ versions of the sysfs interface. "devices" directory at /sys/subsystem/<name>/devices. If /sys/subsystem exists, /sys/bus, /sys/class and /sys/block can be - ignored. If it does not exist, you have always to scan all three + ignored. If it does not exist, you always have to scan all three places, as the kernel is free to move a subsystem from one place to the other, as long as the devices are still reachable by the same subsystem name. @@ -126,7 +125,7 @@ versions of the sysfs interface. - Block The converted block subsystem at /sys/class/block or /sys/subsystem/block will contain the links for disks and partitions - at the same level, never in a hierarchy. Assuming the block subsytem to + at the same level, never in a hierarchy. Assuming the block subsystem to contain only disks and not partition devices in the same flat list is a bug in the application. |