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authorStefan Richter <stefanr@s5r6.in-berlin.de>2010-08-16 23:58:03 +0400
committerStefan Richter <stefanr@s5r6.in-berlin.de>2010-08-19 22:28:25 +0400
commit6c74340bce253ea95c9ee801b3c411a333937edf (patch)
tree4be487165cfc295cba5613094430248f6fb968e9 /drivers/firewire/sbp2.c
parent840fe6359c1db978d01fceb8a023f5f6efdf7f1c (diff)
downloadlinux-6c74340bce253ea95c9ee801b3c411a333937edf.tar.xz
firewire: sbp2: fix memory leak in sbp2_cancel_orbs or at send error
When an ORB was canceled (Command ORB i.e. SCSI request timed out, or Management ORB timed out), or there was a send error in the initial transaction, we missed to drop one of the ORB's references and thus leaked memory. Background: In total, we hold 3 references to each Operation Request Block: - 1 during sbp2_scsi_queuecommand() or sbp2_send_management_orb() respectively, - 1 for the duration of the write transaction to the ORB_Pointer or Management_Agent register of the target, - 1 for as long as the ORB stays within the lu->orb_list, until the ORB is unlinked from the list and the orb->callback was executed. The latter one of these 3 references is finished - normally by sbp2_status_write() when the target wrote status for a pending ORB, - or by sbp2_cancel_orbs() in case of an ORB time-out, - or by complete_transaction() in case of a send error. Of them, the latter two lacked the kref_put. Add the missing kref_put()s. Add comments to the gets and puts of references for transaction callbacks and ORB callbacks so that it is easier to see what is supposed to happen. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/firewire/sbp2.c')
-rw-r--r--drivers/firewire/sbp2.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/firewire/sbp2.c b/drivers/firewire/sbp2.c
index 9f76171717e5..e6cbe491f7ee 100644
--- a/drivers/firewire/sbp2.c
+++ b/drivers/firewire/sbp2.c
@@ -450,7 +450,7 @@ static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
if (&orb->link != &lu->orb_list) {
orb->callback(orb, &status);
- kref_put(&orb->kref, free_orb);
+ kref_put(&orb->kref, free_orb); /* orb callback reference */
} else {
fw_error("status write for unknown orb\n");
}
@@ -480,12 +480,14 @@ static void complete_transaction(struct fw_card *card, int rcode,
if (orb->rcode != RCODE_COMPLETE) {
list_del(&orb->link);
spin_unlock_irqrestore(&card->lock, flags);
+
orb->callback(orb, NULL);
+ kref_put(&orb->kref, free_orb); /* orb callback reference */
} else {
spin_unlock_irqrestore(&card->lock, flags);
}
- kref_put(&orb->kref, free_orb);
+ kref_put(&orb->kref, free_orb); /* transaction callback reference */
}
static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
@@ -501,9 +503,8 @@ static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
list_add_tail(&orb->link, &lu->orb_list);
spin_unlock_irqrestore(&device->card->lock, flags);
- /* Take a ref for the orb list and for the transaction callback. */
- kref_get(&orb->kref);
- kref_get(&orb->kref);
+ kref_get(&orb->kref); /* transaction callback reference */
+ kref_get(&orb->kref); /* orb callback reference */
fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
node_id, generation, device->max_speed, offset,
@@ -530,6 +531,7 @@ static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
orb->rcode = RCODE_CANCELLED;
orb->callback(orb, NULL);
+ kref_put(&orb->kref, free_orb); /* orb callback reference */
}
return retval;