From patchwork Wed Jan 18 09:43:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13106080 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42A27C004D4 for ; Wed, 18 Jan 2023 10:41:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229685AbjARKlA (ORCPT ); Wed, 18 Jan 2023 05:41:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230238AbjARKkL (ORCPT ); Wed, 18 Jan 2023 05:40:11 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75644C4EAA; Wed, 18 Jan 2023 01:44:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=J1bJRn8dMRq79u1+uHawGew6oUOcQ5MnfgpdoCFCIVE=; b=TQTt/SAbg4Elgy7FQ74N+cMV0y 8A+E+kNYML31DWmWs4Vll09VogMb8nddkG06zsPFdV8usGFtyocAqnXN57cmrApq8eZZjnL4n+ifZ WTSXrwV4tlafd1chRE92COzvQG7fg1aSkHlPqml0E6wNASis14pGRrZ4ApGcYImCTW6fX1CTWzUv2 bu3Rale/X80o1JAwkRlkaLUYwMlLzC4QSa5D1tLsDmBgZbAfJpqFOeq/9AzBGbfOUTNRSkmZdrP4t O3Z3gS4V0zEibcUY0AsGOZXdCIYf7ruz2tu+uNRuzijI7EEK8vCpT2jpVCQcGCF3fi9K3tobLD2K6 xqM08S8g==; Received: from 213-147-167-250.nat.highway.webapn.at ([213.147.167.250] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1pI4zR-000AD8-W6; Wed, 18 Jan 2023 09:44:18 +0000 From: Christoph Hellwig To: Andrew Morton , Matthew Wilcox , Hugh Dickins Cc: linux-afs@lists.infradead.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, cluster-devel@redhat.com, linux-mm@kvack.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nilfs@vger.kernel.org Subject: [PATCH 9/9] mm: return an ERR_PTR from __filemap_get_folio Date: Wed, 18 Jan 2023 10:43:29 +0100 Message-Id: <20230118094329.9553-10-hch@lst.de> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230118094329.9553-1-hch@lst.de> References: <20230118094329.9553-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Instead of returning NULL for all errors, distinguish between: - no entry found and not asked to allocated (-ENOENT) - failed to allocate memory (-ENOMEM) - would block (-EAGAIN) so that callers don't have to guess the error based on the passed in flags. Also pass through the error through the direct callers: filemap_get_folio, filemap_lock_folio filemap_grab_folio and filemap_get_incore_folio. Signed-off-by: Christoph Hellwig --- fs/afs/dir.c | 10 +++++----- fs/afs/dir_edit.c | 2 +- fs/afs/write.c | 4 ++-- fs/btrfs/disk-io.c | 2 +- fs/btrfs/extent_io.c | 2 +- fs/ext4/inode.c | 2 +- fs/ext4/move_extent.c | 8 ++++---- fs/gfs2/lops.c | 2 +- fs/hugetlbfs/inode.c | 2 +- fs/iomap/buffered-io.c | 6 +++--- fs/netfs/buffered_read.c | 4 ++-- fs/nilfs2/page.c | 6 +++--- mm/filemap.c | 14 ++++++++------ mm/folio-compat.c | 2 +- mm/huge_memory.c | 2 +- mm/memcontrol.c | 2 +- mm/mincore.c | 2 +- mm/shmem.c | 4 ++-- mm/swap_state.c | 15 ++++++++------- mm/swapfile.c | 4 ++-- mm/truncate.c | 15 ++++++++------- 21 files changed, 57 insertions(+), 53 deletions(-) diff --git a/fs/afs/dir.c b/fs/afs/dir.c index b7c1f8c84b38aa..41d0b4203870be 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -319,16 +319,16 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key) struct folio *folio; folio = filemap_get_folio(mapping, i); - if (!folio) { + if (IS_ERR(folio)) { if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) afs_stat_v(dvnode, n_inval); - - ret = -ENOMEM; folio = __filemap_get_folio(mapping, i, FGP_LOCK | FGP_CREAT, mapping->gfp_mask); - if (!folio) + if (IS_ERR(folio)) { + ret = PTR_ERR(folio); goto error; + } folio_attach_private(folio, (void *)1); folio_unlock(folio); } @@ -524,7 +524,7 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx, */ folio = __filemap_get_folio(dir->i_mapping, ctx->pos / PAGE_SIZE, FGP_ACCESSED, 0); - if (!folio) { + if (IS_ERR(folio)) { ret = afs_bad(dvnode, afs_file_error_dir_missing_page); break; } diff --git a/fs/afs/dir_edit.c b/fs/afs/dir_edit.c index 0ab7752d1b758e..f0eddccbdd9541 100644 --- a/fs/afs/dir_edit.c +++ b/fs/afs/dir_edit.c @@ -115,7 +115,7 @@ static struct folio *afs_dir_get_folio(struct afs_vnode *vnode, pgoff_t index) folio = __filemap_get_folio(mapping, index, FGP_LOCK | FGP_ACCESSED | FGP_CREAT, mapping->gfp_mask); - if (!folio) + if (IS_ERR(folio)) clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags); else if (folio && !folio_test_private(folio)) folio_attach_private(folio, (void *)1); diff --git a/fs/afs/write.c b/fs/afs/write.c index 2d3b08b7406ca7..cf1eb0d122c275 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -232,7 +232,7 @@ static void afs_kill_pages(struct address_space *mapping, _debug("kill %lx (to %lx)", index, last); folio = filemap_get_folio(mapping, index); - if (!folio) { + if (IS_ERR(folio)) { next = index + 1; continue; } @@ -270,7 +270,7 @@ static void afs_redirty_pages(struct writeback_control *wbc, _debug("redirty %llx @%llx", len, start); folio = filemap_get_folio(mapping, index); - if (!folio) { + if (IS_ERR(folio)) { next = index + 1; continue; } diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 7d5da43a89ee7f..f1035e0bcf8c6a 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -4034,7 +4034,7 @@ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors) folio = filemap_get_folio(device->bdev->bd_inode->i_mapping, bytenr >> PAGE_SHIFT); - if (!folio) { + if (IS_ERR(folio)) { errors++; if (i == 0) primary_failed = true; diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index a54d2cf74ba020..faaab9fae66d66 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -230,7 +230,7 @@ void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end) while (index <= end_index) { folio = filemap_get_folio(mapping, index); - if (!folio) + if (IS_ERR(folio)) continue; filemap_dirty_folio(mapping, folio); folio_account_redirty(folio); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index fb6cd994e59afa..ee8f82c7acf9ff 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5391,7 +5391,7 @@ static void ext4_wait_for_tail_page_commit(struct inode *inode) while (1) { struct folio *folio = filemap_lock_folio(inode->i_mapping, inode->i_size >> PAGE_SHIFT); - if (!folio) + if (IS_ERR(folio)) return; ret = __ext4_journalled_invalidate_folio(folio, offset, folio_size(folio) - offset); diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index 2de9829aed63bf..7bf6d069199cbb 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -141,18 +141,18 @@ mext_folio_double_lock(struct inode *inode1, struct inode *inode2, flags = memalloc_nofs_save(); folio[0] = __filemap_get_folio(mapping[0], index1, fgp_flags, mapping_gfp_mask(mapping[0])); - if (!folio[0]) { + if (IS_ERR(folio[0])) { memalloc_nofs_restore(flags); - return -ENOMEM; + return PTR_ERR(folio[0]); } folio[1] = __filemap_get_folio(mapping[1], index2, fgp_flags, mapping_gfp_mask(mapping[1])); memalloc_nofs_restore(flags); - if (!folio[1]) { + if (IS_ERR(folio[1])) { folio_unlock(folio[0]); folio_put(folio[0]); - return -ENOMEM; + return PTR_ERR(folio[1]); } /* * __filemap_get_folio() may not wait on folio's writeback if diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c index 51d4b610127cdb..9e8a00cee8afc1 100644 --- a/fs/gfs2/lops.c +++ b/fs/gfs2/lops.c @@ -472,7 +472,7 @@ static void gfs2_jhead_process_page(struct gfs2_jdesc *jd, unsigned long index, struct folio *folio; folio = filemap_get_folio(jd->jd_inode->i_mapping, index); - if (!folio) + if (IS_ERR(folio)) return; folio_wait_locked(folio); diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 48f1a8ad22431e..19dac1fbcd3705 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -697,7 +697,7 @@ static void hugetlbfs_zero_partial_page(struct hstate *h, struct folio *folio; folio = filemap_lock_folio(mapping, idx); - if (!folio) + if (IS_ERR(folio)) return; start = start & ~huge_page_mask(h); diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 356193e44cf07f..ab5a5a5a3e0283 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -614,8 +614,8 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, folio = __filemap_get_folio(iter->inode->i_mapping, pos >> PAGE_SHIFT, fgp, mapping_gfp_mask(iter->inode->i_mapping)); - if (!folio) { - status = (iter->flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOMEM; + if (IS_ERR(folio)) { + status = PTR_ERR(folio); goto out_no_page; } @@ -882,7 +882,7 @@ static int iomap_write_delalloc_scan(struct inode *inode, /* grab locked page */ folio = filemap_lock_folio(inode->i_mapping, start_byte >> PAGE_SHIFT); - if (!folio) { + if (IS_ERR(folio)) { start_byte = ALIGN_DOWN(start_byte, PAGE_SIZE) + PAGE_SIZE; continue; diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c index 7679a68e819307..209726a9cfdb9c 100644 --- a/fs/netfs/buffered_read.c +++ b/fs/netfs/buffered_read.c @@ -350,8 +350,8 @@ int netfs_write_begin(struct netfs_inode *ctx, retry: folio = __filemap_get_folio(mapping, index, fgp_flags, mapping_gfp_mask(mapping)); - if (!folio) - return -ENOMEM; + if (IS_ERR(folio)) + return PTR_ERR(folio); if (ctx->ops->check_write_begin) { /* Allow the netfs (eg. ceph) to flush conflicts. */ diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c index 41ccd43cd9797f..5cf30827f244c4 100644 --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -259,10 +259,10 @@ int nilfs_copy_dirty_pages(struct address_space *dmap, NILFS_PAGE_BUG(&folio->page, "inconsistent dirty state"); dfolio = filemap_grab_folio(dmap, folio->index); - if (unlikely(!dfolio)) { + if (unlikely(IS_ERR(dfolio))) { /* No empty page is added to the page cache */ - err = -ENOMEM; folio_unlock(folio); + err = PTR_ERR(dfolio); break; } if (unlikely(!folio_buffers(folio))) @@ -311,7 +311,7 @@ void nilfs_copy_back_pages(struct address_space *dmap, folio_lock(folio); dfolio = filemap_lock_folio(dmap, index); - if (dfolio) { + if (!IS_ERR(dfolio)) { /* overwrite existing folio in the destination cache */ WARN_ON(folio_test_dirty(dfolio)); nilfs_copy_page(&dfolio->page, &folio->page, 0); diff --git a/mm/filemap.c b/mm/filemap.c index 35baadd130795c..4037a132f7adcc 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1905,7 +1905,7 @@ void *filemap_get_entry(struct address_space *mapping, pgoff_t index) * * If there is a page cache page, it is returned with an increased refcount. * - * Return: The found folio or %NULL otherwise. + * Return: The found folio or an ERR_PTR() otherwise. */ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, int fgp_flags, gfp_t gfp) @@ -1923,7 +1923,7 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, if (fgp_flags & FGP_NOWAIT) { if (!folio_trylock(folio)) { folio_put(folio); - return NULL; + return ERR_PTR(-EAGAIN); } } else { folio_lock(folio); @@ -1962,7 +1962,7 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, folio = filemap_alloc_folio(gfp, 0); if (!folio) - return NULL; + return ERR_PTR(-ENOMEM); if (WARN_ON_ONCE(!(fgp_flags & (FGP_LOCK | FGP_FOR_MMAP)))) fgp_flags |= FGP_LOCK; @@ -1987,6 +1987,8 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, folio_unlock(folio); } + if (!folio) + return ERR_PTR(-ENOENT); return folio; } EXPORT_SYMBOL(__filemap_get_folio); @@ -3126,7 +3128,7 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) * Do we have something in the page cache already? */ folio = filemap_get_folio(mapping, index); - if (likely(folio)) { + if (likely(!IS_ERR(folio))) { /* * We found the page, so try async readahead before waiting for * the lock. @@ -3155,7 +3157,7 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) folio = __filemap_get_folio(mapping, index, FGP_CREAT|FGP_FOR_MMAP, vmf->gfp_mask); - if (!folio) { + if (IS_ERR(folio)) { if (fpin) goto out_retry; filemap_invalidate_unlock_shared(mapping); @@ -3506,7 +3508,7 @@ static struct folio *do_read_cache_folio(struct address_space *mapping, filler = mapping->a_ops->read_folio; repeat: folio = filemap_get_folio(mapping, index); - if (!folio) { + if (IS_ERR(folio)) { folio = filemap_alloc_folio(gfp, 0); if (!folio) return ERR_PTR(-ENOMEM); diff --git a/mm/folio-compat.c b/mm/folio-compat.c index f3841b4977b68e..4cd173336d8589 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -97,7 +97,7 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, struct folio *folio; folio = __filemap_get_folio(mapping, index, fgp_flags, gfp); - if (!folio) + if (IS_ERR(folio)) return NULL; return folio_file_page(folio, index); } diff --git a/mm/huge_memory.c b/mm/huge_memory.c index a2830019aaa017..b0c9170632e37c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3103,7 +3103,7 @@ static int split_huge_pages_in_file(const char *file_path, pgoff_t off_start, struct folio *folio = filemap_get_folio(mapping, index); nr_pages = 1; - if (!folio) + if (IS_ERR(folio)) continue; if (!folio_test_large(folio)) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 893427aded0191..8bcea91099d218 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5693,7 +5693,7 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma, /* shmem/tmpfs may report page out on swap: account for that too. */ index = linear_page_index(vma, addr); folio = filemap_get_incore_folio(vma->vm_file->f_mapping, index); - if (!folio) + if (IS_ERR(folio)) return NULL; return folio_file_page(folio, index); } diff --git a/mm/mincore.c b/mm/mincore.c index a085a2aeabd8e6..386c1aed1a8aef 100644 --- a/mm/mincore.c +++ b/mm/mincore.c @@ -61,7 +61,7 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t index) * tmpfs's .fault). So swapped out tmpfs mappings are tested here. */ folio = filemap_get_incore_folio(mapping, index); - if (folio) { + if (!IS_ERR(folio)) { present = folio_test_uptodate(folio); folio_put(folio); } diff --git a/mm/shmem.c b/mm/shmem.c index 769107f376562f..676318f95f7b40 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -603,7 +603,7 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, index = (inode->i_size & HPAGE_PMD_MASK) >> PAGE_SHIFT; folio = filemap_get_folio(inode->i_mapping, index); - if (!folio) + if (IS_ERR(folio)) goto drop; /* No huge page at the end of the file: nothing to split */ @@ -3187,7 +3187,7 @@ static const char *shmem_get_link(struct dentry *dentry, if (!dentry) { folio = filemap_get_folio(inode->i_mapping, 0); - if (!folio) + if (IS_ERR(folio)) return ERR_PTR(-ECHILD); if (PageHWPoison(folio_page(folio, 0)) || !folio_test_uptodate(folio)) { diff --git a/mm/swap_state.c b/mm/swap_state.c index c39ea34bc4fc10..e853d3eecf55bb 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -330,7 +330,7 @@ struct folio *swap_cache_get_folio(swp_entry_t entry, struct folio *folio; folio = filemap_get_folio(swap_address_space(entry), swp_offset(entry)); - if (folio) { + if (!IS_ERR(folio)) { bool vma_ra = swap_use_vma_readahead(); bool readahead; @@ -360,6 +360,8 @@ struct folio *swap_cache_get_folio(swp_entry_t entry, if (!vma || !vma_ra) atomic_inc(&swapin_readahead_hits); } + } else { + folio = NULL; } return folio; @@ -383,22 +385,21 @@ struct folio *filemap_get_incore_folio(struct address_space *mapping, struct folio *folio = filemap_get_entry(mapping, index); if (!xa_is_value(folio)) - goto out; + return folio; if (!shmem_mapping(mapping)) - return NULL; + return ERR_PTR(-ENOENT); swp = radix_to_swp_entry(folio); /* There might be swapin error entries in shmem mapping. */ if (non_swap_entry(swp)) - return NULL; + return ERR_PTR(-ENOENT); /* Prevent swapoff from happening to us */ si = get_swap_device(swp); if (!si) - return NULL; + return ERR_PTR(-ENOENT); index = swp_offset(swp); folio = filemap_get_folio(swap_address_space(swp), index); put_swap_device(si); -out: return folio; } @@ -425,7 +426,7 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, folio = filemap_get_folio(swap_address_space(entry), swp_offset(entry)); put_swap_device(si); - if (folio) + if (!IS_ERR(folio)) return folio_file_page(folio, swp_offset(entry)); /* diff --git a/mm/swapfile.c b/mm/swapfile.c index a5729273480e07..a128b61b6b8c91 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -136,7 +136,7 @@ static int __try_to_reclaim_swap(struct swap_info_struct *si, int ret = 0; folio = filemap_get_folio(swap_address_space(entry), offset); - if (!folio) + if (IS_ERR(folio)) return 0; /* * When this function is called from scan_swap_map_slots() and it's @@ -2096,7 +2096,7 @@ static int try_to_unuse(unsigned int type) entry = swp_entry(type, i); folio = filemap_get_folio(swap_address_space(entry), i); - if (!folio) + if (IS_ERR(folio)) continue; /* diff --git a/mm/truncate.c b/mm/truncate.c index 7b4ea4c4a46b20..86de31ed4d3238 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -375,7 +375,7 @@ void truncate_inode_pages_range(struct address_space *mapping, same_folio = (lstart >> PAGE_SHIFT) == (lend >> PAGE_SHIFT); folio = __filemap_get_folio(mapping, lstart >> PAGE_SHIFT, FGP_LOCK, 0); - if (folio) { + if (!IS_ERR(folio)) { same_folio = lend < folio_pos(folio) + folio_size(folio); if (!truncate_inode_partial_folio(folio, lstart, lend)) { start = folio->index + folio_nr_pages(folio); @@ -387,14 +387,15 @@ void truncate_inode_pages_range(struct address_space *mapping, folio = NULL; } - if (!same_folio) + if (!same_folio) { folio = __filemap_get_folio(mapping, lend >> PAGE_SHIFT, FGP_LOCK, 0); - if (folio) { - if (!truncate_inode_partial_folio(folio, lstart, lend)) - end = folio->index; - folio_unlock(folio); - folio_put(folio); + if (!IS_ERR(folio)) { + if (!truncate_inode_partial_folio(folio, lstart, lend)) + end = folio->index; + folio_unlock(folio); + folio_put(folio); + } } index = start;