2024-02-02 21:03:28

by Mathieu Desnoyers

[permalink] [raw]
Subject: [RFC PATCH v4 03/12] dm: Treat alloc_dax() -EOPNOTSUPP failure as non-fatal

In preparation for checking whether the architecture has data cache
aliasing within alloc_dax(), modify the error handling of dm alloc_dev()
to treat alloc_dax() -EOPNOTSUPP failure as non-fatal.

For the transition, consider that alloc_dax() returning NULL is the
same as returning -EOPNOTSUPP.

Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches")
Suggested-by: Dan Williams <[email protected]>
Signed-off-by: Mathieu Desnoyers <[email protected]>
Cc: Alasdair Kergon <[email protected]>
Cc: Mike Snitzer <[email protected]>
Cc: Mikulas Patocka <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Russell King <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
drivers/md/dm.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 23c32cd1f1d8..2fc22cae9089 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2054,6 +2054,7 @@ static void cleanup_mapped_device(struct mapped_device *md)
static struct mapped_device *alloc_dev(int minor)
{
int r, numa_node_id = dm_get_numa_node();
+ struct dax_device *dax_dev;
struct mapped_device *md;
void *old_md;

@@ -2122,15 +2123,15 @@ static struct mapped_device *alloc_dev(int minor)
md->disk->private_data = md;
sprintf(md->disk->disk_name, "dm-%d", minor);

- if (IS_ENABLED(CONFIG_FS_DAX)) {
- md->dax_dev = alloc_dax(md, &dm_dax_ops);
- if (IS_ERR(md->dax_dev)) {
- md->dax_dev = NULL;
+ dax_dev = alloc_dax(md, &dm_dax_ops);
+ if (IS_ERR_OR_NULL(dax_dev)) {
+ if (IS_ERR(dax_dev) && PTR_ERR(dax_dev) != -EOPNOTSUPP)
goto bad;
- }
- set_dax_nocache(md->dax_dev);
- set_dax_nomc(md->dax_dev);
- if (dax_add_host(md->dax_dev, md->disk))
+ } else {
+ set_dax_nocache(dax_dev);
+ set_dax_nomc(dax_dev);
+ md->dax_dev = dax_dev;
+ if (dax_add_host(dax_dev, md->disk))
goto bad;
}

--
2.39.2