The patch titled Subject: mm, fadvise: don't return -EINVAL when filesystem cannot implement fadvise() has been added to the -mm tree. Its filename is mm-fadvise-dont-return-einval-when-filesystem-cannot-implement-fadvise.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/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Subject: mm, fadvise: don't return -EINVAL when filesystem cannot implement fadvise() Eric Wong reported his test suite failex when /tmp is tmpfs. https://lkml.org/lkml/2012/2/24/479 Currentlt the input check of POSIX_FADV_WILLNEED has two problems. - requires a_ops->readpage. But in fact, force_page_cache_readahead() requires that the target filesystem has either ->readpage or ->readpages. - returns -EINVAL when the filesystem doesn't have ->readpage. But posix says that fadvise is merely a hint. Thus fadvise() should return 0 if filesystem has no means of implementing fadvise(). The userland application should not know nor care whcih type of filesystem backs the TMPDIR directory, as Eric pointed out. There is nothing which userspace can do to solve this error. So change the return value to 0 when filesytem doesn't support readahead. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Hillf Danton <dhillf@xxxxxxxxx> Signed-off-by: Eric Wong <normalperson@xxxxxxxx> Tested-by: Eric Wong <normalperson@xxxxxxxx> Reviewed-by: Wanlong Gao <gaowanlong@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/fadvise.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff -puN mm/fadvise.c~mm-fadvise-dont-return-einval-when-filesystem-cannot-implement-fadvise mm/fadvise.c --- a/mm/fadvise.c~mm-fadvise-dont-return-einval-when-filesystem-cannot-implement-fadvise +++ a/mm/fadvise.c @@ -93,11 +93,6 @@ SYSCALL_DEFINE(fadvise64_64)(int fd, lof spin_unlock(&file->f_lock); break; case POSIX_FADV_WILLNEED: - if (!mapping->a_ops->readpage) { - ret = -EINVAL; - break; - } - /* First and last PARTIAL page! */ start_index = offset >> PAGE_CACHE_SHIFT; end_index = endbyte >> PAGE_CACHE_SHIFT; @@ -106,12 +101,13 @@ SYSCALL_DEFINE(fadvise64_64)(int fd, lof nrpages = end_index - start_index + 1; if (!nrpages) nrpages = ~0UL; - - ret = force_page_cache_readahead(mapping, file, - start_index, - nrpages); - if (ret > 0) - ret = 0; + + /* + * Ignore return value because fadvise() shall return + * success even if filesystem can't retrieve a hint, + */ + force_page_cache_readahead(mapping, file, start_index, + nrpages); break; case POSIX_FADV_NOREUSE: break; _ Subject: Subject: mm, fadvise: don't return -EINVAL when filesystem cannot implement fadvise() Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are linux-next.patch memory-hotplug-fix-invalid-memory-access-caused-by-stale-kswapd-pointer.patch memory-hotplug-fix-invalid-memory-access-caused-by-stale-kswapd-pointer-fix.patch c-r-prctl-less-paranoid-prctl_set_mm_exe_file.patch hugetlb-rename-max_hstate-to-hugetlb_max_hstate.patch hugetlb-dont-use-err_ptr-with-vm_fault-values.patch hugetlb-add-an-inline-helper-for-finding-hstate-index.patch hugetlb-use-mmu_gather-instead-of-a-temporary-linked-list-for-accumulating-pages.patch hugetlb-avoid-taking-i_mmap_mutex-in-unmap_single_vma-for-hugetlb.patch hugetlb-simplify-migrate_huge_page.patch hugetlb-add-a-list-for-tracking-in-use-hugetlb-pages.patch hugetlb-make-some-static-variables-global.patch mm-hugetlb-add-new-hugetlb-cgroup.patch hugetlb-cgroup-add-the-cgroup-pointer-to-page-lru.patch hugetlb-cgroup-add-charge-uncharge-routines-for-hugetlb-cgroup.patch hugetlb-cgroup-add-support-for-cgroup-removal.patch hugetlb-cgroup-add-hugetlb-cgroup-control-files.patch hugetlb-cgroup-migrate-hugetlb-cgroup-info-from-oldpage-to-new-page-during-migration.patch hugetlb-cgroup-add-hugetlb-controller-documentation.patch mm-oom-do-not-schedule-if-current-has-been-killed.patch mm-fadvise-dont-return-einval-when-filesystem-cannot-implement-fadvise.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html