This can be applied to the block's for-2.6.36.
=
From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Subject: [PATCH] scsi: unify the error handling of the prep functions
This unifies the error handling of the prep functions (and fix the
leak of a page allocated for discard in the case of BLKPREP_KILL or
BLK_PREP_DEFER).
The error handling of the prep path is very messy. Some errors are
handled in the prep functions while some are in scsi_prep_return().
Let's handle all the errors in scsi_prep_return().
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 26 +++++++++++++-------------
drivers/scsi/sd.c | 6 ++++--
2 files changed, 17 insertions(+), 15 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index ee83619..f9b3f7b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1008,14 +1008,7 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
}
return BLKPREP_OK ;
-
err_exit:
- scsi_release_buffers(cmd);
- if (error == BLKPREP_KILL)
- scsi_put_command(cmd);
- else /* BLKPREP_DEFER */
- scsi_unprep_request(cmd->request);
-
return error;
}
EXPORT_SYMBOL(scsi_init_io);
@@ -1177,6 +1170,17 @@ int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
}
EXPORT_SYMBOL(scsi_prep_state_check);
+static void scsi_prep_error(struct request *req)
+{
+ struct scsi_cmnd *cmd = req->special;
+
+ if (!cmd)
+ return;
+
+ scsi_release_buffers(cmd);
+ scsi_unprep_request(req);
+}
+
int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
{
struct scsi_device *sdev = q->queuedata;
@@ -1185,14 +1189,10 @@ int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
case BLKPREP_KILL:
req->errors = DID_NO_CONNECT << 16;
/* release the command and kill it */
- if (req->special) {
- struct scsi_cmnd *cmd = req->special;
- scsi_release_buffers(cmd);
- scsi_put_command(cmd);
- req->special = NULL;
- }
+ scsi_prep_error(req);
break;
case BLKPREP_DEFER:
+ scsi_prep_error(req);
/*
* If we defer, the blk_peek_request() returns NULL, but the
* queue must be restarted, so we plug here if no returning
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index aa6b48b..88ba0c5 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -473,8 +473,10 @@ static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq)
static void sd_unprep_fn(struct request_queue *q, struct request *rq)
{
- if (rq->cmd_flags & REQ_DISCARD)
- __free_page(virt_to_page(rq->buffer));
+ if (rq->cmd_flags & REQ_DISCARD) {
+ free_page((unsigned long)rq->buffer);
+ rq->buffer = NULL;
+ }
}
/**
--
1.6.5
--
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