From: Andrew Morton <akpm@linux-foundation.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>,
Hugh Dickins <hughd@google.com>,
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: Re: return an ERR_PTR from __filemap_get_folio v2
Date: Sat, 21 Jan 2023 17:06:41 -0800 [thread overview]
Message-ID: <20230121170641.121f4224a0e8304765bb4738@linux-foundation.org> (raw)
In-Reply-To: <20230121065755.1140136-1-hch@lst.de>
On Sat, 21 Jan 2023 07:57:48 +0100 Christoph Hellwig <hch@lst.de> wrote:
> Hi all,
>
> __filemap_get_folio and its wrappers can return NULL for three different
> conditions, which in some cases requires the caller to reverse engineer
> the decision making. This is fixed by returning an ERR_PTR instead of
> NULL and thus transporting the reason for the failure. But to make
> that work we first need to ensure that no xa_value special case is
> returned and thus return the FGP_ENTRY flag. It turns out that flag
> is barely used and can usually be deal with in a better way.
>
> Note that the shmem patches in here are non-trivial and need some
> careful review and testing.
I'll hide for a while, awaiting that review. Plus...
> Changes since v1:
> - drop the patches to check for errors in btrfs and gfs2
> - document the new calling conventions for the wrappers around
> __filemap_get_folio
> - rebased against the iomap changes in latest linux-next
This patchset doesn't apply to fs/btrfs/ because linux-next contains
this 6+ month-old commit:
commit 964688b32d9ada55a7fce2e650d85ef24188f73f
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
AuthorDate: Tue May 17 18:03:27 2022 -0400
Commit: Matthew Wilcox (Oracle) <willy@infradead.org>
CommitDate: Wed Jun 29 08:51:07 2022 -0400
btrfs: Use a folio in wait_dev_supers()
Matthew, what's the story here?
next prev parent reply other threads:[~2023-01-22 1:06 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-21 6:57 Christoph Hellwig
2023-01-21 6:57 ` [PATCH 1/7] mm: don't look at xarray value entries in split_huge_pages_in_file Christoph Hellwig
2023-01-21 6:57 ` [PATCH 2/7] mm: make mapping_get_entry available outside of filemap.c Christoph Hellwig
2023-01-21 6:57 ` [PATCH 3/7] mm: use filemap_get_entry in filemap_get_incore_folio Christoph Hellwig
2023-01-21 6:57 ` [PATCH 4/7] shmem: remove shmem_get_partial_folio Christoph Hellwig
2023-01-21 6:57 ` [PATCH 5/7] shmem: open code the page cache lookup in shmem_get_folio_gfp Christoph Hellwig
2023-01-21 6:57 ` [PATCH 6/7] mm: remove FGP_ENTRY Christoph Hellwig
2023-01-21 6:57 ` [PATCH 7/7] mm: return an ERR_PTR from __filemap_get_folio Christoph Hellwig
2023-01-21 11:52 ` kernel test robot
2023-01-21 14:28 ` Christoph Hellwig
2023-01-23 15:44 ` David Sterba
2023-01-26 17:24 ` Ryusuke Konishi
2023-03-10 4:31 ` Naoya Horiguchi
2023-03-10 7:00 ` Christoph Hellwig
2023-03-10 8:02 ` Naoya Horiguchi
2023-01-22 1:06 ` Andrew Morton [this message]
2023-01-22 7:20 ` return an ERR_PTR from __filemap_get_folio v2 Christoph Hellwig
2023-01-23 18:59 ` Andrew Morton
2023-01-23 19:18 ` Christoph Hellwig
2023-03-28 23:04 ` Andrew Morton
2023-03-29 23:56 ` Christoph Hellwig
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