mirror of
https://github.com/torvalds/linux.git
synced 2024-11-06 03:51:48 +00:00
fb0af3f2b1
Using /dev/pstore as a mount point for the pstore filesystem is slightly awkward. We don't normally mount filesystems in /dev/ and the /dev/pstore file isn't created automatically by anything. While this method will still work, we can create a persistent mount point in sysfs. This will put pstore on par with things like cgroups and efivarfs. Signed-off-by: Josh Boyer <jwboyer@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
48 lines
1.7 KiB
Plaintext
48 lines
1.7 KiB
Plaintext
Where: /sys/fs/pstore/... (or /dev/pstore/...)
|
|
Date: March 2011
|
|
Kernel Version: 2.6.39
|
|
Contact: tony.luck@intel.com
|
|
Description: Generic interface to platform dependent persistent storage.
|
|
|
|
Platforms that provide a mechanism to preserve some data
|
|
across system reboots can register with this driver to
|
|
provide a generic interface to show records captured in
|
|
the dying moments. In the case of a panic the last part
|
|
of the console log is captured, but other interesting
|
|
data can also be saved.
|
|
|
|
# mount -t pstore -o kmsg_bytes=8000 - /sys/fs/pstore
|
|
|
|
$ ls -l /sys/fs/pstore/
|
|
total 0
|
|
-r--r--r-- 1 root root 7896 Nov 30 15:38 dmesg-erst-1
|
|
|
|
Different users of this interface will result in different
|
|
filename prefixes. Currently two are defined:
|
|
|
|
"dmesg" - saved console log
|
|
"mce" - architecture dependent data from fatal h/w error
|
|
|
|
Once the information in a file has been read, removing
|
|
the file will signal to the underlying persistent storage
|
|
device that it can reclaim the space for later re-use.
|
|
|
|
$ rm /sys/fs/pstore/dmesg-erst-1
|
|
|
|
The expectation is that all files in /sys/fs/pstore/
|
|
will be saved elsewhere and erased from persistent store
|
|
soon after boot to free up space ready for the next
|
|
catastrophe.
|
|
|
|
The 'kmsg_bytes' mount option changes the target amount of
|
|
data saved on each oops/panic. Pstore saves (possibly
|
|
multiple) files based on the record size of the underlying
|
|
persistent storage until at least this amount is reached.
|
|
Default is 10 Kbytes.
|
|
|
|
Pstore only supports one backend at a time. If multiple
|
|
backends are available, the preferred backend may be
|
|
set by passing the pstore.backend= argument to the kernel at
|
|
boot time.
|
|
|