I confirmed that mkfs.xfs worked with Intel X25-M (trim) and
scsi_debug (write same and unmap).
REQ_TYPE_FS should give the same scsi_cmnd struct as REQ_TYPE_BLOCK_PC.
This can be applied to block's for-2.6.36.
The git tree is also available:
git://git.kernel.org/pub/scm/linux/kernel/git/tomo/linux-2.6-misc.git fs-discard
=
From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Subject: [PATCH] scsi: convert discard to REQ_TYPE_FS instead of REQ_TYPE_BLOCK_PC
The block layer (file systems) sends discard requests as REQ_TYPE_FS
(the role of REQ_TYPE_FS is that setting up commands and interpreting
the results). But SCSI-ml treats discard requests as
REQ_TYPE_BLOCK_PC.
scsi-ml can handle discard requests as REQ_TYPE_FS
easily. scsi_setup_discard_cmnd() sets up struct request and the bio
nicely. Only remaining issue is that discard requests can't be
completed partially so we need to modify sd_done.
This conversion also fixes the problem that discard requests aren't
retried when possible (e.g. UNIT ATTENTION).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
drivers/scsi/sd.c | 7 ++++++-
1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 0994ab6..5f59601 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -433,7 +433,6 @@ static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq)
nr_sectors >>= 3;
}
- rq->cmd_type = REQ_TYPE_BLOCK_PC;
rq->timeout = SD_TIMEOUT;
memset(rq->cmd, 0, rq->cmd_len);
@@ -1185,6 +1184,12 @@ static int sd_done(struct scsi_cmnd *SCpnt)
int sense_valid = 0;
int sense_deferred = 0;
+ if (SCpnt->request->cmd_flags & REQ_DISCARD) {
+ if (!result)
+ scsi_set_resid(SCpnt, 0);
+ return good_bytes;
+ }
+
if (result) {
sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
if (sense_valid)
--
1.6.5
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