diff options
| author | David S. Miller <davem@davemloft.net> | 2013-08-01 18:08:34 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-08-01 18:08:34 -0700 |
| commit | 21af8107f27878813d0364733c0b08813c2c192a (patch) | |
| tree | 5a5f4867228e9e394ef9dc75f59878eba268eaf7 /drivers/scsi/esp_scsi.c | |
| parent | ab2abda6377723e0d5fbbfe5f5aa16a5523344d1 (diff) | |
| download | linux-21af8107f27878813d0364733c0b08813c2c192a.tar.bz2 | |
esp_scsi: Fix tag state corruption when autosensing.
Meelis Roos reports a crash in esp_free_lun_tag() in the presense
of a disk which has died.
The issue is that when we issue an autosense command, we do so by
hijacking the original command that caused the check-condition.
When we do so we clear out the ent->tag[] array when we issue it via
find_and_prep_issuable_command(). This is so that the autosense
command is forced to be issued non-tagged.
That is problematic, because it is the value of ent->tag[] which
determines whether we issued the original scsi command as tagged
vs. non-tagged (see esp_alloc_lun_tag()).
And that, in turn, is what trips up the sanity checks in
esp_free_lun_tag(). That function needs the original ->tag[] values
in order to free up the tag slot properly.
Fix this by remembering the original command's tag values, and
having esp_alloc_lun_tag() and esp_free_lun_tag() use them.
Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/scsi/esp_scsi.c')
| -rw-r--r-- | drivers/scsi/esp_scsi.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c index 34552bf1c023..55548dc5cec3 100644 --- a/drivers/scsi/esp_scsi.c +++ b/drivers/scsi/esp_scsi.c @@ -530,7 +530,7 @@ static int esp_need_to_nego_sync(struct esp_target_data *tp) static int esp_alloc_lun_tag(struct esp_cmd_entry *ent, struct esp_lun_data *lp) { - if (!ent->tag[0]) { + if (!ent->orig_tag[0]) { /* Non-tagged, slot already taken? */ if (lp->non_tagged_cmd) return -EBUSY; @@ -564,9 +564,9 @@ static int esp_alloc_lun_tag(struct esp_cmd_entry *ent, return -EBUSY; } - BUG_ON(lp->tagged_cmds[ent->tag[1]]); + BUG_ON(lp->tagged_cmds[ent->orig_tag[1]]); - lp->tagged_cmds[ent->tag[1]] = ent; + lp->tagged_cmds[ent->orig_tag[1]] = ent; lp->num_tagged++; return 0; @@ -575,9 +575,9 @@ static int esp_alloc_lun_tag(struct esp_cmd_entry *ent, static void esp_free_lun_tag(struct esp_cmd_entry *ent, struct esp_lun_data *lp) { - if (ent->tag[0]) { - BUG_ON(lp->tagged_cmds[ent->tag[1]] != ent); - lp->tagged_cmds[ent->tag[1]] = NULL; + if (ent->orig_tag[0]) { + BUG_ON(lp->tagged_cmds[ent->orig_tag[1]] != ent); + lp->tagged_cmds[ent->orig_tag[1]] = NULL; lp->num_tagged--; } else { BUG_ON(lp->non_tagged_cmd != ent); @@ -667,6 +667,8 @@ static struct esp_cmd_entry *find_and_prep_issuable_command(struct esp *esp) ent->tag[0] = 0; ent->tag[1] = 0; } + ent->orig_tag[0] = ent->tag[0]; + ent->orig_tag[1] = ent->tag[1]; if (esp_alloc_lun_tag(ent, lp) < 0) continue; |