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author | Amir Shehata <amir.shehata@intel.com> | 2016-02-22 17:29:18 -0500 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-22 18:05:49 -0800 |
commit | 341bc96085f4dfbc2427d746753faf9edf789f90 (patch) | |
tree | f6292ba8717405a9be8971c2794d4d8e2084fede /drivers/staging/lustre/lnet/lnet/module.c | |
parent | 94bfb3cff238514d4049f719bfe99116f51d1c8c (diff) | |
download | op-kernel-dev-341bc96085f4dfbc2427d746753faf9edf789f90.zip op-kernel-dev-341bc96085f4dfbc2427d746753faf9edf789f90.tar.gz |
staging: lustre: prevent assert on LNet module unload
There is a use case where lnet can be unloaded while there are
no NIs configured. Removing lnet in this case will cause
LNetFini() to be called without a prior call to LNetNIFini().
This will cause the LASSERT(the_lnet.ln_refcount == 0) to be
triggered.
To deal with this use case when LNet is configured a reference
count on the module is taken using try_module_get(). This way
LNet must be unconfigured before it could be removed; therefore
avoiding the above case. When LNet is unconfigured module_put()
is called to return the reference count.
Signed-off-by: Amir Shehata <amir.shehata@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6010
Reviewed-on: http://review.whamcloud.com/13110
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/lustre/lnet/lnet/module.c')
-rw-r--r-- | drivers/staging/lustre/lnet/lnet/module.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lnet/lnet/module.c b/drivers/staging/lustre/lnet/lnet/module.c index 8f053d7..e12fe37 100644 --- a/drivers/staging/lustre/lnet/lnet/module.c +++ b/drivers/staging/lustre/lnet/lnet/module.c @@ -53,13 +53,21 @@ lnet_configure(void *arg) mutex_lock(&lnet_config_mutex); if (!the_lnet.ln_niinit_self) { + rc = try_module_get(THIS_MODULE); + + if (rc != 1) + goto out; + rc = LNetNIInit(LNET_PID_LUSTRE); if (rc >= 0) { the_lnet.ln_niinit_self = 1; rc = 0; + } else { + module_put(THIS_MODULE); } } +out: mutex_unlock(&lnet_config_mutex); return rc; } @@ -74,6 +82,7 @@ lnet_unconfigure(void) if (the_lnet.ln_niinit_self) { the_lnet.ln_niinit_self = 0; LNetNIFini(); + module_put(THIS_MODULE); } mutex_lock(&the_lnet.ln_api_mutex); |