drm/pagemap Fix error paths in drm_pagemap_migrate_to_devmem

Avoid unlocking and putting device pages unless they were successfully
locked, and do not calculate migrated_pages on error paths.

Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Fixes: 75af93b3f5d0 ("drm/pagemap, drm/xe: Support destination migration over interconnect")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Francois Dugast <francois.dugast@intel.com>
Link: https://patch.msgid.link/20260107182716.2236607-2-matthew.brost@intel.com

diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
index ba099aa7c52fd36df4aa244bdb8d072b31e8bbab..aa43a8475100fca159c4d823dd2c3fb05de01490 100644 (file)
--- a/drivers/gpu/drm/drm_pagemap.c
+++ b/drivers/gpu/drm/drm_pagemap.c
@@ -582,7 +582,7 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
 
        err = ops->populate_devmem_pfn(devmem_allocation, npages, migrate.dst);
        if (err)
-               goto err_finalize;
+               goto err_aborted_migration;
 
        own_pages = 0;
 
@@ -621,8 +621,10 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
                err = drm_pagemap_migrate_range(devmem_allocation, migrate.src, migrate.dst,
                                                pages, pagemap_addr, &last, &cur,
                                                mdetails);
-               if (err)
+               if (err) {
+                       npages = i + 1;
                        goto err_finalize;
+               }
        }
        cur.start = npages;
        cur.ops = NULL; /* Force migration */
@@ -646,7 +648,7 @@ err_finalize:
 err_aborted_migration:
        migrate_vma_pages(&migrate);
 
-       for (i = 0; i < npages;) {
+       for (i = 0; !err && i < npages;) {
                struct page *page = migrate_pfn_to_page(migrate.src[i]);
                unsigned long nr_pages = page ? NR_PAGES(folio_order(page_folio(page))) : 1;