diff options
Diffstat (limited to 'mm/gup.c')
| -rw-r--r-- | mm/gup.c | 33 |
1 files changed, 19 insertions, 14 deletions
@@ -2394,20 +2394,25 @@ err: } /* - * Check whether all folios are *allowed* to be pinned indefinitely (longterm). + * Check whether all folios are *allowed* to be pinned indefinitely (long term). * Rather confusingly, all folios in the range are required to be pinned via * FOLL_PIN, before calling this routine. * - * If any folios in the range are not allowed to be pinned, then this routine - * will migrate those folios away, unpin all the folios in the range and return - * -EAGAIN. The caller should re-pin the entire range with FOLL_PIN and then - * call this routine again. + * Return values: * - * If an error other than -EAGAIN occurs, this indicates a migration failure. - * The caller should give up, and propagate the error back up the call stack. - * - * If everything is OK and all folios in the range are allowed to be pinned, + * 0: if everything is OK and all folios in the range are allowed to be pinned, * then this routine leaves all folios pinned and returns zero for success. + * + * -EAGAIN: if any folios in the range are not allowed to be pinned, then this + * routine will migrate those folios away, unpin all the folios in the range. If + * migration of the entire set of folios succeeds, then -EAGAIN is returned. The + * caller should re-pin the entire range with FOLL_PIN and then call this + * routine again. + * + * -ENOMEM, or any other -errno: if an error *other* than -EAGAIN occurs, this + * indicates a migration failure. The caller should give up, and propagate the + * error back up the call stack. The caller does not need to unpin any folios in + * that case, because this routine will do the unpinning. */ static long check_and_migrate_movable_folios(unsigned long nr_folios, struct folio **folios) @@ -2425,10 +2430,8 @@ static long check_and_migrate_movable_folios(unsigned long nr_folios, } /* - * This routine just converts all the pages in the @pages array to folios and - * calls check_and_migrate_movable_folios() to do the heavy lifting. - * - * Please see the check_and_migrate_movable_folios() documentation for details. + * Return values and behavior are the same as those for + * check_and_migrate_movable_folios(). */ static long check_and_migrate_movable_pages(unsigned long nr_pages, struct page **pages) @@ -2437,8 +2440,10 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages, long i, ret; folios = kmalloc_array(nr_pages, sizeof(*folios), GFP_KERNEL); - if (!folios) + if (!folios) { + unpin_user_pages(pages, nr_pages); return -ENOMEM; + } for (i = 0; i < nr_pages; i++) folios[i] = page_folio(pages[i]); |