The patch titled Subject: mm-shmem-return-head-page-from-find_lock_entry-fix has been added to the -mm tree. Its filename is mm-shmem-return-head-page-from-find_lock_entry-fix.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-shmem-return-head-page-from-find_lock_entry-fix.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-shmem-return-head-page-from-find_lock_entry-fix.patch 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 and is updated there every 3-4 working days ------------------------------------------------------ From: Matthew Wilcox <willy@xxxxxxxxxxxxx> Subject: mm-shmem-return-head-page-from-find_lock_entry-fix fix BUG()s [1] https://lore.kernel.org/linux-mm/20200912032042.GA6583@xxxxxxxxxxxxxxxxxxxx/ Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/shmem.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/mm/shmem.c~mm-shmem-return-head-page-from-find_lock_entry-fix +++ a/mm/shmem.c @@ -1803,7 +1803,7 @@ static int shmem_getpage_gfp(struct inod struct mm_struct *charge_mm; struct page *page; enum sgp_type sgp_huge = sgp; - pgoff_t hindex; + pgoff_t hindex = index; int error; int once = 0; int alloced = 0; @@ -1832,6 +1832,8 @@ repeat: return error; } + if (page) + hindex = page->index; if (page && sgp == SGP_WRITE) mark_page_accessed(page); @@ -1842,6 +1844,7 @@ repeat: unlock_page(page); put_page(page); page = NULL; + hindex = index; } if (page || sgp == SGP_READ) goto out; @@ -1992,7 +1995,7 @@ clear: goto unlock; } out: - *pagep = page + index - page->index; + *pagep = page + index - hindex; return 0; /* _ Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are mm-debug-do-not-dereference-i_ino-blindly.patch mm-factor-find_get_incore_page-out-of-mincore_page.patch mm-use-find_get_incore_page-in-memcontrol.patch mm-optimise-madvise-willneed.patch mm-optimise-madvise-willneed-fix.patch proc-optimise-smaps-for-shmem-entries.patch i915-use-find_lock_page-instead-of-find_lock_entry.patch mm-convert-find_get_entry-to-return-the-head-page.patch mm-convert-find_get_entry-to-return-the-head-page-fix.patch mm-shmem-return-head-page-from-find_lock_entry.patch mm-shmem-return-head-page-from-find_lock_entry-fix.patch mm-add-find_lock_head.patch mm-filemap-fix-filemap_map_pages-for-thp.patch mm-account-pmd-tables-like-pte-tables.patch mm-move-pagedoublemap-bit.patch mm-simplify-pagedoublemap-with-pf_second-policy.patch xarray-add-xa_get_order.patch xarray-add-xas_split.patch xarray-add-xas_split-fix-2.patch mm-filemap-fix-storing-to-a-thp-shadow-entry.patch mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps.patch mm-memory-remove-page-fault-assumption-of-compound-page-size.patch mm-page_owner-change-split_page_owner-to-take-a-count.patch mm-huge_memory-fix-page_trans_huge_mapcount-assumption-of-thp-size.patch mm-huge_memory-fix-can_split_huge_page-assumption-of-thp-size.patch mm-rmap-fix-assumptions-of-thp-size.patch mm-truncate-fix-truncation-for-pages-of-arbitrary-size.patch mm-page-writeback-support-tail-pages-in-wait_for_stable_page.patch mm-vmscan-allow-arbitrary-sized-pages-to-be-paged-out.patch mm-readahead-add-define_readahead.patch mm-readahead-make-page_cache_ra_unbounded-take-a-readahead_control.patch mm-readahead-make-do_page_cache_ra-take-a-readahead_control.patch mm-readahead-add-page_cache_sync_ra-and-page_cache_async_ra.patch harden-autofs-ioctl-table.patch