When a LUN is removed, the sdev that is associated with the LUN
remains intact until its reference count drops to 0. In order
to prevent an sdev from being removed while a context is still
associated with it, obtain an additional reference per-context
for each LUN attached to the context.
This resolves a potential Oops in the release handler when a
dealing with a LUN that has already been removed.
Signed-off-by: Matthew R. Ochs <mrochs@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Manoj N. Kumar <manoj@xxxxxxxxxxxxxxxxxx>
Suggested-by: Brian King <brking@xxxxxxxxxxxxxxxxxx>
---
drivers/scsi/cxlflash/superpipe.c | 36 ++++++++++++++++++++++++------------
1 file changed, 24 insertions(+), 12 deletions(-)
diff --git a/drivers/scsi/cxlflash/superpipe.c b/drivers/scsi/cxlflash/superpipe.c
index fa513ba..1fa4af6 100644
--- a/drivers/scsi/cxlflash/superpipe.c
+++ b/drivers/scsi/cxlflash/superpipe.c
@@ -880,6 +880,9 @@ static int _cxlflash_disk_detach(struct scsi_device *sdev,
sys_close(lfd);
}
+ /* Release the sdev reference that bound this LUN to the context */
+ scsi_device_put(sdev);
+
out:
if (put_ctx)
put_context(ctxi);
@@ -1287,11 +1290,18 @@ static int cxlflash_disk_attach(struct scsi_device *sdev,
}
}
+ rc = scsi_device_get(sdev);
+ if (unlikely(rc)) {
+ dev_err(dev, "%s: Unable to get sdev reference!\n", __func__);
+ goto out;
+ }
+
lun_access = kzalloc(sizeof(*lun_access), GFP_KERNEL);
if (unlikely(!lun_access)) {
dev_err(dev, "%s: Unable to allocate lun_access!\n", __func__);
+ scsi_device_put(sdev);
rc = -ENOMEM;
- goto out;
+ goto err0;
}
lun_access->lli = lli;
@@ -1311,21 +1321,21 @@ static int cxlflash_disk_attach(struct scsi_device *sdev,
dev_err(dev, "%s: Could not initialize context %p\n",
__func__, ctx);
rc = -ENODEV;
- goto err0;
+ goto err1;
}
ctxid = cxl_process_element(ctx);
if (unlikely((ctxid > MAX_CONTEXT) || (ctxid < 0))) {
dev_err(dev, "%s: ctxid (%d) invalid!\n", __func__, ctxid);
rc = -EPERM;
- goto err1;
+ goto err2;
}
file = cxl_get_fd(ctx, &cfg->cxl_fops, &fd);
if (unlikely(fd < 0)) {
rc = -ENODEV;
dev_err(dev, "%s: Could not get file descriptor\n", __func__);
- goto err1;
+ goto err2;
}
/* Translate read/write O_* flags from fcntl.h to AFU permission bits */
@@ -1335,7 +1345,7 @@ static int cxlflash_disk_attach(struct scsi_device *sdev,
if (unlikely(!ctxi)) {
dev_err(dev, "%s: Failed to create context! (%d)\n",
__func__, ctxid);
- goto err2;
+ goto err3;
}
work = &ctxi->work;
@@ -1346,13 +1356,13 @@ static int cxlflash_disk_attach(struct scsi_device *sdev,
if (unlikely(rc)) {
dev_dbg(dev, "%s: Could not start context rc=%d\n",
__func__, rc);
- goto err3;
+ goto err4;
}
rc = afu_attach(cfg, ctxi);
if (unlikely(rc)) {
dev_err(dev, "%s: Could not attach AFU rc %d\n", __func__, rc);
- goto err4;
+ goto err5;
}
/*
@@ -1388,13 +1398,13 @@ out:
__func__, ctxid, fd, attach->block_size, rc, attach->last_lba);
return rc;
-err4:
+err5:
cxl_stop_context(ctx);
-err3:
+err4:
put_context(ctxi);
destroy_context(cfg, ctxi);
ctxi = NULL;
-err2:
+err3:
/*
* Here, we're overriding the fops with a dummy all-NULL fops because
* fput() calls the release fop, which will cause us to mistakenly
@@ -1406,10 +1416,12 @@ err2:
fput(file);
put_unused_fd(fd);
fd = -1;
-err1:
+err2:
cxl_release_context(ctx);
-err0:
+err1:
kfree(lun_access);
+err0:
+ scsi_device_put(sdev);
goto out;
}
--
2.1.0
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