[PATCH V4] Save command pool address of Scsi_Host

From: jgross
Date: Mon Aug 04 2014 - 07:24:28 EST


From: Juergen Gross <jgross@xxxxxxxx>

If a scsi host driver specifies .cmd_len in it's scsi_host_template, a driver's
private command pool is needed. scsi_find_host_cmd_pool() will locate it, but
scsi_alloc_host_cmd_pool() isn't saving the pool address in the host template.

This will result in an access error when the host is removed.

Avoid the problem by saving the address of a new allocated command pool where
it is expected.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
drivers/scsi/scsi.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 88d46fe..f654ac1 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -380,6 +380,10 @@ scsi_alloc_host_cmd_pool(struct Scsi_Host *shost)
pool->slab_flags |= SLAB_CACHE_DMA;
pool->gfp_mask = __GFP_DMA;
}
+
+ if (hostt->cmd_size)
+ hostt->cmd_pool = pool;
+
return pool;
}

@@ -424,8 +428,10 @@ out:
out_free_slab:
kmem_cache_destroy(pool->cmd_slab);
out_free_pool:
- if (hostt->cmd_size)
- scsi_free_host_cmd_pool(pool);
+ if (hostt->cmd_size) {
+ scsi_free_host_cmd_pool(hostt->cmd_pool);
+ hostt->cmd_pool = NULL;
+ }
goto out;
}

@@ -447,8 +453,10 @@ static void scsi_put_host_cmd_pool(struct Scsi_Host *shost)
if (!--pool->users) {
kmem_cache_destroy(pool->cmd_slab);
kmem_cache_destroy(pool->sense_slab);
- if (hostt->cmd_size)
- scsi_free_host_cmd_pool(pool);
+ if (hostt->cmd_size) {
+ scsi_free_host_cmd_pool(hostt->cmd_pool);
+ hostt->cmd_pool = NULL;
+ }
}
mutex_unlock(&host_cmd_pool_mutex);
}
--
1.8.4.5

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