From 2a8ccf3187aff6defed72f7d8fa562ff2f69ef2a Mon Sep 17 00:00:00 2001 From: "Stephen M. Cameron" Date: Thu, 4 Feb 2010 08:43:41 -0600 Subject: [PATCH] [SCSI] hpsa: fix bug in adjust_hpsa_scsi_table fix bug in adjust_hpsa_scsi_table which caused devices which have changed size, etc. to do the wrong thing. The problem was as follows: The driver maintains its current idea of what devices are present in the h->dev[] array. When it updates this array, it scans the hardware, and produces a new list of devices, call it sd[], for scsi devices. Then, it compares each item in h->dev[] vs. sd[], and any items which are not present sd it removes from h->dev[], and any items present in sd[], but different, it modifies in h->dev[]. Then, it looks for items in sd[] which are not present in h->dev[], and adds those items into h->dev[]. All the while, it keeps track of what items were added and removed to/from h->dev[]. Finally, it updates the SCSI mid-layer by removing and adding the same devices it removed and added to/from h->dev[]. (modified devices count as a remove then add.) originally, when a "changed" device was discovered, it was removed then added to h->dev[]. The item was added to the *end* of h->dev[]. And, the item was removed from sd[] as well (nulled out). As it processed h->dev[], these newly added items at the end of the list were encountered, and sd[] was searched, but those items were nulled out. So they ended up getting removed immediately after they were added. The solution is to have a way to replace items in the h->dev[] array instead of doing a remove + add. Then the "changed" items. are not encountered a second time, and removed. Signed-off-by: Stephen M. Cameron Signed-off-by: James Bottomley --- drivers/scsi/hpsa.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 2764cb605693..6b40221a7220 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -675,6 +675,24 @@ lun_assigned: return 0; } +/* Replace an entry from h->dev[] array. */ +static void hpsa_scsi_replace_entry(struct ctlr_info *h, int hostno, + int entry, struct hpsa_scsi_dev_t *new_entry, + struct hpsa_scsi_dev_t *added[], int *nadded, + struct hpsa_scsi_dev_t *removed[], int *nremoved) +{ + /* assumes h->devlock is held */ + BUG_ON(entry < 0 || entry >= HPSA_MAX_SCSI_DEVS_PER_HBA); + removed[*nremoved] = h->dev[entry]; + (*nremoved)++; + h->dev[entry] = new_entry; + added[*nadded] = new_entry; + (*nadded)++; + dev_info(&h->pdev->dev, "%s device c%db%dt%dl%d changed.\n", + scsi_device_type(new_entry->devtype), hostno, new_entry->bus, + new_entry->target, new_entry->lun); +} + /* Remove an entry from h->dev[] array. */ static void hpsa_scsi_remove_entry(struct ctlr_info *h, int hostno, int entry, struct hpsa_scsi_dev_t *removed[], int *nremoved) @@ -835,12 +853,8 @@ static void adjust_hpsa_scsi_table(struct ctlr_info *h, int hostno, continue; /* remove ^^^, hence i not incremented */ } else if (device_change == DEVICE_CHANGED) { changes++; - hpsa_scsi_remove_entry(h, hostno, i, - removed, &nremoved); - (void) hpsa_scsi_add_entry(h, hostno, sd[entry], - added, &nadded); - /* add can't fail, we just removed one. */ - + hpsa_scsi_replace_entry(h, hostno, i, sd[entry], + added, &nadded, removed, &nremoved); /* Set it to NULL to prevent it from being freed * at the bottom of hpsa_update_scsi_devices() */