dax/fsdev: don't leave a dangling dev_dax->pgmap on probe failure

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After the dynamic path set dev_dax->pgmap, any later probe failure left
dev_dax->pgmap dangling: devres frees the devm_kzalloc'd pgmap on probe
failure, and subsequent probe attempts would hit the "dynamic-dax with
pre-populated page map" check and fail permanently.

Factor pgmap acquisition out into fsdev_acquire_pgmap(), and defer the
dev_dax->pgmap assignment until probe can no longer fail. A failed probe
now never publishes the pointer at all, so there is nothing to unwind.
This also matches kill_dev_dax(), which already clears the dynamic pgmap
pointer on unbind: dev_dax->pgmap is now non-NULL only while the pgmap
is actually valid.

Refactor suggested by Dave Jiang.

Fixes: d5406bd458 ("dax: add fsdev.c driver for fs-dax on character dax")

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: John Groves <john@groves.net>
Link: https://patch.msgid.link/0100019ecc092ca1-ffc7a5fd-1252-4be5-882c-fd5efdc102a9-000000@email.amazonses.com
Signed-off-by: Alison Schofield <alison.schofield@intel.com>

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John Groves 2026-06-15 16:06:53 +00:00 • committed by Alison Schofield

parent e023922993

commit caf906009d

1 changed files with 49 additions and 28 deletions

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drivers/dax/fsdev.c

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