The patch titled Subject: dcssblk: handle alloc_dax() -EOPNOTSUPP failure has been added to the -mm mm-unstable branch. Its filename is dcssblk-handle-alloc_dax-eopnotsupp-failure.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/dcssblk-handle-alloc_dax-eopnotsupp-failure.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Subject: dcssblk: handle alloc_dax() -EOPNOTSUPP failure Date: Thu, 8 Feb 2024 13:49:05 -0500 In preparation for checking whether the architecture has data cache aliasing within alloc_dax(), modify the error handling of dcssblk dcssblk_add_store() to handle alloc_dax() -EOPNOTSUPP failures. Considering that s390 is not a data cache aliasing architecture, and considering that DCSSBLK selects DAX, a return value of -EOPNOTSUPP from alloc_dax() should make dcssblk_add_store() fail. For the transition, consider that alloc_dax() returning NULL is the same as returning -EOPNOTSUPP. Link: https://lkml.kernel.org/r/20240208184913.484340-5-mathieu.desnoyers@xxxxxxxxxxxx Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Cc: Alasdair Kergon <agk@xxxxxxxxxx> Cc: Mike Snitzer <snitzer@xxxxxxxxxx> Cc: Mikulas Patocka <mpatocka@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx> Cc: Dave Jiang <dave.jiang@xxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/s390/block/dcssblk.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/drivers/s390/block/dcssblk.c~dcssblk-handle-alloc_dax-eopnotsupp-failure +++ a/drivers/s390/block/dcssblk.c @@ -549,6 +549,7 @@ dcssblk_add_store(struct device *dev, st int rc, i, j, num_of_segments; struct dcssblk_dev_info *dev_info; struct segment_info *seg_info, *temp; + struct dax_device *dax_dev; char *local_buf; unsigned long seg_byte_size; @@ -677,13 +678,13 @@ dcssblk_add_store(struct device *dev, st if (rc) goto put_dev; - dev_info->dax_dev = alloc_dax(dev_info, &dcssblk_dax_ops); - if (IS_ERR(dev_info->dax_dev)) { - rc = PTR_ERR(dev_info->dax_dev); - dev_info->dax_dev = NULL; + dax_dev = alloc_dax(dev_info, &dcssblk_dax_ops); + if (IS_ERR_OR_NULL(dax_dev)) { + rc = IS_ERR(dax_dev) ? PTR_ERR(dax_dev) : -EOPNOTSUPP; goto put_dev; } - set_dax_synchronous(dev_info->dax_dev); + set_dax_synchronous(dax_dev); + dev_info->dax_dev = dax_dev; rc = dax_add_host(dev_info->dax_dev, dev_info->gd); if (rc) goto out_dax; _ Patches currently in -mm which might be from mathieu.desnoyers@xxxxxxxxxxxx are nvdimm-pmem-fix-leak-on-dax_add_host-failure.patch nvdimm-pmem-treat-alloc_dax-eopnotsupp-failure-as-non-fatal.patch dm-treat-alloc_dax-eopnotsupp-failure-as-non-fatal.patch dcssblk-handle-alloc_dax-eopnotsupp-failure.patch virtio-treat-alloc_dax-eopnotsupp-failure-as-non-fatal.patch dax-check-for-data-cache-aliasing-at-runtime.patch introduce-cpu_dcache_is_aliasing-across-all-architectures.patch dax-fix-incorrect-list-of-data-cache-aliasing-architectures.patch nvdimm-pmem-cleanup-alloc_dax-error-handling.patch dm-cleanup-alloc_dax-error-handling.patch dcssblk-cleanup-alloc_dax-error-handling.patch virtio-cleanup-alloc_dax-error-handling.patch