From 48c9d11375fc66f1e59d0e9b27d121e015a50904 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 7 Mar 2023 15:34:09 +0100 Subject: mm: remove FGP_ENTRY FGP_ENTRY is unused now, so remove it. Link: https://lkml.kernel.org/r/20230307143410.28031-7-hch@lst.de Signed-off-by: Christoph Hellwig Cc: Andreas Gruenbacher Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Ryusuke Konishi Signed-off-by: Andrew Morton --- mm/folio-compat.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/folio-compat.c') diff --git a/mm/folio-compat.c b/mm/folio-compat.c index cabcd1de9ecb..1754daa85d35 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -97,8 +97,8 @@ 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 || xa_is_value(folio)) - return &folio->page; + if (!folio) + return NULL; return folio_file_page(folio, index); } EXPORT_SYMBOL(pagecache_get_page); -- cgit v1.2.3 From 66dabbb65d673aef40dd17bf62c042be8f6d4a4b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 7 Mar 2023 15:34:10 +0100 Subject: mm: return an ERR_PTR from __filemap_get_folio 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. [hch@lst.de: fix null-pointer deref] Link: https://lkml.kernel.org/r/20230310070023.GA13563@lst.de Link: https://lkml.kernel.org/r/20230310043137.GA1624890@u2004 Link: https://lkml.kernel.org/r/20230307143410.28031-8-hch@lst.de Signed-off-by: Christoph Hellwig Acked-by: Ryusuke Konishi [nilfs2] Cc: Andreas Gruenbacher Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Naoya Horiguchi Signed-off-by: Andrew Morton --- fs/afs/dir.c | 10 +++++----- fs/afs/dir_edit.c | 2 +- fs/afs/write.c | 4 ++-- fs/ext4/inode.c | 2 +- fs/ext4/move_extent.c | 8 ++++---- fs/hugetlbfs/inode.c | 2 +- fs/iomap/buffered-io.c | 11 ++--------- fs/netfs/buffered_read.c | 4 ++-- fs/nfs/file.c | 4 ++-- fs/nilfs2/page.c | 6 +++--- include/linux/pagemap.h | 11 ++++++----- mm/filemap.c | 14 ++++++++------ mm/folio-compat.c | 2 +- mm/huge_memory.c | 2 +- mm/hugetlb.c | 6 ++++-- mm/memcontrol.c | 2 +- mm/mincore.c | 2 +- mm/shmem.c | 4 ++-- mm/swap_state.c | 17 ++++++++++------- mm/swapfile.c | 4 ++-- mm/truncate.c | 15 ++++++++------- 21 files changed, 67 insertions(+), 65 deletions(-) (limited to 'mm/folio-compat.c') diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 82690d1dd49a..f92b9e62d567 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -319,16 +319,16 @@ expand: 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 0ab7752d1b75..f0eddccbdd95 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 571f3b9a417e..c822d6006033 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/ext4/inode.c b/fs/ext4/inode.c index bf0b7dea4900..d7973743417b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5395,7 +5395,7 @@ 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 2de9829aed63..7bf6d069199c 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/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 9062da6da567..702d79639c0d 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 6f4c97a6d7e9..96bb56c203f4 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -468,19 +468,12 @@ EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate); struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos) { unsigned fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE | FGP_NOFS; - struct folio *folio; if (iter->flags & IOMAP_NOWAIT) fgp |= FGP_NOWAIT; - folio = __filemap_get_folio(iter->inode->i_mapping, pos >> PAGE_SHIFT, + return __filemap_get_folio(iter->inode->i_mapping, pos >> PAGE_SHIFT, fgp, mapping_gfp_mask(iter->inode->i_mapping)); - if (folio) - return folio; - - if (iter->flags & IOMAP_NOWAIT) - return ERR_PTR(-EAGAIN); - return ERR_PTR(-ENOMEM); } EXPORT_SYMBOL_GPL(iomap_get_folio); @@ -911,7 +904,7 @@ 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 7679a68e8193..209726a9cfdb 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/nfs/file.c b/fs/nfs/file.c index 893625eacab9..1d03406e6c03 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -336,8 +336,8 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping, start: folio = nfs_folio_grab_cache_write_begin(mapping, pos >> PAGE_SHIFT); - if (!folio) - return -ENOMEM; + if (IS_ERR(folio)) + return PTR_ERR(folio); *pagep = &folio->page; ret = nfs_flush_incompatible(file, folio); diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c index 41ccd43cd979..5cf30827f244 100644 --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -259,10 +259,10 @@ repeat: 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 @@ repeat: 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/include/linux/pagemap.h b/include/linux/pagemap.h index 306a0f63cea8..fdcd595d2294 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -520,7 +520,8 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, * Looks up the page cache entry at @mapping & @index. If a folio is * present, it is returned with an increased refcount. * - * Otherwise, %NULL is returned. + * Return: A folio or ERR_PTR(-ENOENT) if there is no folio in the cache for + * this index. Will not return a shadow, swap or DAX entry. */ static inline struct folio *filemap_get_folio(struct address_space *mapping, pgoff_t index) @@ -537,8 +538,8 @@ static inline struct folio *filemap_get_folio(struct address_space *mapping, * present, it is returned locked with an increased refcount. * * Context: May sleep. - * Return: A folio or %NULL if there is no folio in the cache for this - * index. Will not return a shadow, swap or DAX entry. + * Return: A folio or ERR_PTR(-ENOENT) if there is no folio in the cache for + * this index. Will not return a shadow, swap or DAX entry. */ static inline struct folio *filemap_lock_folio(struct address_space *mapping, pgoff_t index) @@ -555,8 +556,8 @@ static inline struct folio *filemap_lock_folio(struct address_space *mapping, * a new folio is created. The folio is locked, marked as accessed, and * returned. * - * Return: A found or created folio. NULL if no folio is found and failed to - * create a folio. + * Return: A found or created folio. ERR_PTR(-ENOMEM) if no folio is found + * and failed to create a folio. */ static inline struct folio *filemap_grab_folio(struct address_space *mapping, pgoff_t index) diff --git a/mm/filemap.c b/mm/filemap.c index ac161b50f5bc..a34abfe8c654 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1907,7 +1907,7 @@ out: * * 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) @@ -1925,7 +1925,7 @@ repeat: if (fgp_flags & FGP_NOWAIT) { if (!folio_trylock(folio)) { folio_put(folio); - return NULL; + return ERR_PTR(-EAGAIN); } } else { folio_lock(folio); @@ -1964,7 +1964,7 @@ no_page: 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; @@ -1989,6 +1989,8 @@ no_page: folio_unlock(folio); } + if (!folio) + return ERR_PTR(-ENOENT); return folio; } EXPORT_SYMBOL(__filemap_get_folio); @@ -3258,7 +3260,7 @@ 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. @@ -3287,7 +3289,7 @@ retry_find: 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); @@ -3638,7 +3640,7 @@ 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 1754daa85d35..2511c055a35f 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 70008dd7f215..2d860e70fe88 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3092,7 +3092,7 @@ 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/hugetlb.c b/mm/hugetlb.c index 07abcb6eb203..712e32b38295 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5780,7 +5780,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, */ new_folio = false; folio = filemap_lock_folio(mapping, idx); - if (!folio) { + if (IS_ERR(folio)) { size = i_size_read(mapping->host) >> huge_page_shift(h); if (idx >= size) goto out; @@ -6071,6 +6071,8 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, vma_end_reservation(h, vma, haddr); pagecache_folio = filemap_lock_folio(mapping, idx); + if (IS_ERR(pagecache_folio)) + pagecache_folio = NULL; } ptl = huge_pte_lock(h, mm, ptep); @@ -6182,7 +6184,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, if (is_continue) { ret = -EFAULT; folio = filemap_lock_folio(mapping, idx); - if (!folio) + if (IS_ERR(folio)) goto out; folio_in_pagecache = true; } else if (!*pagep) { diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 13ec89c45389..0524add35cae 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5705,7 +5705,7 @@ 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 d359650b0f75..2d5be013a25a 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 93cb39852a16..fa6e38f2f55f 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -605,7 +605,7 @@ next: 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 */ @@ -3214,7 +3214,7 @@ 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 92234f4b51d2..b76a65ac28b3 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -336,7 +336,7 @@ 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; @@ -366,6 +366,8 @@ struct folio *swap_cache_get_folio(swp_entry_t entry, if (!vma || !vma_ra) atomic_inc(&swapin_readahead_hits); } + } else { + folio = NULL; } return folio; @@ -388,23 +390,24 @@ struct folio *filemap_get_incore_folio(struct address_space *mapping, struct swap_info_struct *si; struct folio *folio = filemap_get_entry(mapping, index); + if (!folio) + return ERR_PTR(-ENOENT); 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; } @@ -431,7 +434,7 @@ 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 c1b97436f811..00b3e46becad 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 @@ -2095,7 +2095,7 @@ retry: 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 7b4ea4c4a46b..86de31ed4d32 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; -- cgit v1.2.3