From: Chris Horn <chris.horn@xxxxxxx>
If libcfs_debug_mb parameter is specified to insmod (i.e. set before
module is initialized) then it does not get initialized correctly.
libcfs_param_debug_mb_set() expects cfs_trace_get_debug_mb() to return
zero if the module has not been initialized yet, but
cfs_trace_get_debug_mb() will return 1 in this case. Modify
cfs_trace_get_debug_mb() to return zero as expected. A related issue
is that in this case we need to call cfs_trace_get_debug_mb() after
cfs_tracefile_init() so that libcfs_debug_mb gets the same value it
would get if we had set it after module init.
When libcfs_debug_mb is specified to insmod, libcfs_debug_init()
divides its value by num_possible_cpus(), but this is already done in
libcfs_param_debug_mb_set().
Fixes: 205b154f3b ("lustre: always range-check libcfs_debug_mb setting.")
HPE-bug-id: LUS-10839
WC-bug-id: https://jira.whamcloud.com/browse/LU-15689
Lustre-commit: d38ef181d8250b083 ("LU-15689 libcfs: libcfs_debug_mb set incorrectly on init")
Signed-off-by: Chris Horn <chris.horn@xxxxxxx>
Reviewed-on: https://review.whamcloud.com/46925
Reviewed-by: Neil Brown <neilb@xxxxxxx>
Reviewed-by: James Simmons <jsimmons@xxxxxxxxxxxxx>
Reviewed-by: Oleg Drokin <green@xxxxxxxxxxxxx>
Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx>
---
net/lnet/libcfs/debug.c | 9 +++------
net/lnet/libcfs/tracefile.c | 5 ++++-
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/net/lnet/libcfs/debug.c b/net/lnet/libcfs/debug.c
index f8ff5f7..c00e6da 100644
--- a/net/lnet/libcfs/debug.c
+++ b/net/lnet/libcfs/debug.c
@@ -544,12 +544,10 @@ int libcfs_debug_init(unsigned long bufsize)
/* If libcfs_debug_mb is uninitialized then just make the
* total buffers smp_num_cpus * TCD_MAX_PAGES
*/
- if (max < num_possible_cpus()) {
+ if (max < num_possible_cpus())
max = TCD_MAX_PAGES;
- } else {
- max = max / num_possible_cpus();
+ else
max <<= (20 - PAGE_SHIFT);
- }
rc = cfs_tracefile_init(max);
if (rc)
@@ -557,8 +555,7 @@ int libcfs_debug_init(unsigned long bufsize)
libcfs_register_panic_notifier();
kernel_param_lock(THIS_MODULE);
- if (libcfs_debug_mb == 0)
- libcfs_debug_mb = cfs_trace_get_debug_mb();
+ libcfs_debug_mb = cfs_trace_get_debug_mb();
kernel_param_unlock(THIS_MODULE);
return rc;
}
diff --git a/net/lnet/libcfs/tracefile.c b/net/lnet/libcfs/tracefile.c
index 948eaaa..f0b7a2e 100644
--- a/net/lnet/libcfs/tracefile.c
+++ b/net/lnet/libcfs/tracefile.c
@@ -1000,7 +1000,10 @@ int cfs_trace_get_debug_mb(void)
up_read(&cfs_tracefile_sem);
- return (total_pages >> (20 - PAGE_SHIFT)) + 1;
+ if (total_pages)
+ return (total_pages >> (20 - PAGE_SHIFT)) + 1;
+ else
+ return 0;
}
static int tracefiled(void *arg)
--
1.8.3.1
|