On 2/27/20 5:58 PM, Douglas Gilbert wrote:
Since the version 2 driver, the state of the driver can be found
with 'cat /proc/scsi/sg/debug'. As the driver becomes more
threaded and IO faster (e.g. scsi_debug with a command timer
of 5 microseconds), the existing state dump can become
misleading as the state can change during the "snapshot". The
new approach in this patch is to allocate a buffer of
SG_PROC_DEBUG_SZ bytes and use scnprintf() to populate it. Only
when the whole state is captured (or the buffer fills) is the
output to the caller's terminal performed. The previous
approach was line based: assemble a line of information and
then output it.
Locks are taken as required for short periods and should not
interfere with a disk IO intensive program. Operations
such as closing a sg file descriptor or removing a sg device
may be held up for a short while (microseconds).
Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
---
drivers/scsi/sg.c | 256 ++++++++++++++++++++++++++++++++--------------
1 file changed, 177 insertions(+), 79 deletions(-)
Personally, I'm not a big fan of using procfs to display driver status.
I would rather move this interface to debugfs and declare the existing
interface as deprecated.
We probably would need to observe the usual rules etc (compat functions,
compile-time config etc), but I really would like to deprecate using
procfs in SCSI...
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
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