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/write.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/afs/write.c') 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; } -- cgit v1.2.3 From a2b6f2ab3e144f8e23666aafeba0e4d9ea4b7975 Mon Sep 17 00:00:00 2001 From: "Vishal Moola (Oracle)" Date: Wed, 7 Jun 2023 13:41:19 -0700 Subject: afs: Fix dangling folio ref counts in writeback Commit acc8d8588cb7 converted afs_writepages_region() to write back a folio batch. If writeback needs rescheduling, the function exits without dropping the references to the folios in fbatch. This patch fixes that. [DH: Moved the added line before the _leave()] Fixes: acc8d8588cb7 ("afs: convert afs_writepages_region() to use filemap_get_folios_tag()") Signed-off-by: Vishal Moola (Oracle) Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/20230607204120.89416-1-vishal.moola@gmail.com/ --- fs/afs/write.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/afs/write.c') diff --git a/fs/afs/write.c b/fs/afs/write.c index c822d6006033..fd433024070e 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -763,6 +763,7 @@ static int afs_writepages_region(struct address_space *mapping, if (wbc->sync_mode == WB_SYNC_NONE) { if (skips >= 5 || need_resched()) { *_next = start; + folio_batch_release(&fbatch); _leave(" = 0 [%llx]", *_next); return 0; } -- cgit v1.2.3 From 819da022dd007398d0c42ebcd8dbb1b681acea53 Mon Sep 17 00:00:00 2001 From: "Vishal Moola (Oracle)" Date: Wed, 7 Jun 2023 13:41:20 -0700 Subject: afs: Fix waiting for writeback then skipping folio Commit acc8d8588cb7 converted afs_writepages_region() to write back a folio batch. The function waits for writeback to a folio, but then proceeds to the rest of the batch without trying to write that folio again. This patch fixes has it attempt to write the folio again. [DH: Also remove an 'else' that adding a goto makes redundant] Fixes: acc8d8588cb7 ("afs: convert afs_writepages_region() to use filemap_get_folios_tag()") Signed-off-by: Vishal Moola (Oracle) Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/20230607204120.89416-2-vishal.moola@gmail.com/ --- fs/afs/write.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'fs/afs/write.c') diff --git a/fs/afs/write.c b/fs/afs/write.c index fd433024070e..8750b99c3f56 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -731,6 +731,7 @@ static int afs_writepages_region(struct address_space *mapping, * (changing page->mapping to NULL), or even swizzled * back from swapper_space to tmpfs file mapping */ +try_again: if (wbc->sync_mode != WB_SYNC_NONE) { ret = folio_lock_killable(folio); if (ret < 0) { @@ -757,9 +758,10 @@ static int afs_writepages_region(struct address_space *mapping, #ifdef CONFIG_AFS_FSCACHE folio_wait_fscache(folio); #endif - } else { - start += folio_size(folio); + goto try_again; } + + start += folio_size(folio); if (wbc->sync_mode == WB_SYNC_NONE) { if (skips >= 5 || need_resched()) { *_next = start; -- cgit v1.2.3