Commit de7ee9a2 authored by Bart Van Assche's avatar Bart Van Assche Committed by Nicholas Bellinger

tcm_fc: Wait for command completion before freeing a session

This patch avoids that the following kernel crash can occur with
later patches in this patch series:

general protection fault: 0000 [#1] SMP
CPU: 0 PID: 6 Comm: kworker/u8:0 Not tainted 4.3.0-rc1-debug+ #1
Workqueue: tmr-fileio target_tmr_work [target_core_mod]
Call Trace:
 [<ffffffff810a6915>] lock_acquire+0x65/0x90
 [<ffffffff815e740b>] _raw_spin_lock_irqsave+0x4b/0x60
 [<ffffffffa03bc7ca>] target_release_cmd_kref+0x2a/0xa0 [target_core_mod]
 [<ffffffffa03bd418>] target_put_sess_cmd+0x28/0x50 [target_core_mod]
 [<ffffffffa03bad50>] core_tmr_lun_reset+0x390/0x640 [target_core_mod]
 [<ffffffffa03bce50>] target_tmr_work+0x80/0xd0 [target_core_mod]
 [<ffffffff81070e6d>] process_one_work+0x19d/0x430
 [<ffffffff8107120f>] worker_thread+0x10f/0x460
 [<ffffffff810772ba>] kthread+0xea/0x100
 [<ffffffff815e7a2f>] ret_from_fork+0x3f/0x70
Signed-off-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent f0a8afec
...@@ -260,6 +260,14 @@ static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id) ...@@ -260,6 +260,14 @@ static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id)
return NULL; return NULL;
} }
static void ft_close_sess(struct ft_sess *sess)
{
transport_deregister_session_configfs(sess->se_sess);
target_sess_cmd_list_set_waiting(sess->se_sess);
target_wait_for_sess_cmds(sess->se_sess);
ft_sess_put(sess);
}
/* /*
* Delete all sessions from tport. * Delete all sessions from tport.
* Caller holds ft_lport_lock. * Caller holds ft_lport_lock.
...@@ -273,8 +281,7 @@ static void ft_sess_delete_all(struct ft_tport *tport) ...@@ -273,8 +281,7 @@ static void ft_sess_delete_all(struct ft_tport *tport)
head < &tport->hash[FT_SESS_HASH_SIZE]; head++) { head < &tport->hash[FT_SESS_HASH_SIZE]; head++) {
hlist_for_each_entry_rcu(sess, head, hash) { hlist_for_each_entry_rcu(sess, head, hash) {
ft_sess_unhash(sess); ft_sess_unhash(sess);
transport_deregister_session_configfs(sess->se_sess); ft_close_sess(sess); /* release from table */
ft_sess_put(sess); /* release from table */
} }
} }
} }
...@@ -313,8 +320,7 @@ void ft_sess_close(struct se_session *se_sess) ...@@ -313,8 +320,7 @@ void ft_sess_close(struct se_session *se_sess)
pr_debug("port_id %x\n", port_id); pr_debug("port_id %x\n", port_id);
ft_sess_unhash(sess); ft_sess_unhash(sess);
mutex_unlock(&ft_lport_lock); mutex_unlock(&ft_lport_lock);
transport_deregister_session_configfs(se_sess); ft_close_sess(sess);
ft_sess_put(sess);
/* XXX Send LOGO or PRLO */ /* XXX Send LOGO or PRLO */
synchronize_rcu(); /* let transport deregister happen */ synchronize_rcu(); /* let transport deregister happen */
} }
...@@ -460,8 +466,7 @@ static void ft_prlo(struct fc_rport_priv *rdata) ...@@ -460,8 +466,7 @@ static void ft_prlo(struct fc_rport_priv *rdata)
return; return;
} }
mutex_unlock(&ft_lport_lock); mutex_unlock(&ft_lport_lock);
transport_deregister_session_configfs(sess->se_sess); ft_close_sess(sess); /* release from table */
ft_sess_put(sess); /* release from table */
rdata->prli_count--; rdata->prli_count--;
/* XXX TBD - clearing actions. unit attn, see 4.10 */ /* XXX TBD - clearing actions. unit attn, see 4.10 */
} }
......
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