Re: [PATCH 1/4] netfs: Don't use certain internal folio_*() functions

[Jeff Layton <jlayton@kernel.org>]

On Tue, 2024-01-09 at 18:01 +0000, David Howells wrote:
> Filesystems should not be using folio->index not folio_index(folio) and
> folio->mapping, not folio_mapping() or folio_file_mapping() in filesystem
> code.
> 

nit: Awkwardly worded sentence above. The first part sounds wrong too:

"Filesystems should not be using folio->index not folio_index(folio)"

I'm guessing you mean:

"Filesystems should be using folio->index, not folio_index(folio) since
they know that it's in the pagecache."

> Change this automagically with:
> 
> perl -p -i -e 's/folio_mapping[(]([^)]*)[)]/\1->mapping/g' fs/netfs/*.c
> perl -p -i -e 's/folio_file_mapping[(]([^)]*)[)]/\1->mapping/g' fs/netfs/*.c
> perl -p -i -e 's/folio_index[(]([^)]*)[)]/\1->index/g' fs/netfs/*.c

FWIW, coccinelle is really much nicer for this sort of thing.

> Reported-by: Matthew Wilcox <willy@infradead.org>
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Jeff Layton <jlayton@kernel.org>
> cc: linux-afs@lists.infradead.org
> cc: linux-cachefs@redhat.com
> cc: linux-cifs@vger.kernel.org
> cc: linux-erofs@lists.ozlabs.org
> cc: linux-fsdevel@vger.kernel.org
> ---
>  fs/netfs/buffered_read.c  | 12 ++++++------
>  fs/netfs/buffered_write.c | 10 +++++-----
>  fs/netfs/io.c             |  2 +-
>  fs/netfs/misc.c           |  2 +-
>  4 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
> index a59e7b2edaac..3298c29b5548 100644
> --- a/fs/netfs/buffered_read.c
> +++ b/fs/netfs/buffered_read.c
> @@ -101,7 +101,7 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
>  		}
>  
>  		if (!test_bit(NETFS_RREQ_DONT_UNLOCK_FOLIOS, &rreq->flags)) {
> -			if (folio_index(folio) == rreq->no_unlock_folio &&
> +			if (folio->index == rreq->no_unlock_folio &&
>  			    test_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags))
>  				_debug("no unlock");
>  			else
> @@ -246,13 +246,13 @@ EXPORT_SYMBOL(netfs_readahead);
>   */
>  int netfs_read_folio(struct file *file, struct folio *folio)
>  {
> -	struct address_space *mapping = folio_file_mapping(folio);
> +	struct address_space *mapping = folio->mapping;
>  	struct netfs_io_request *rreq;
>  	struct netfs_inode *ctx = netfs_inode(mapping->host);
>  	struct folio *sink = NULL;
>  	int ret;
>  
> -	_enter("%lx", folio_index(folio));
> +	_enter("%lx", folio->index);
>  
>  	rreq = netfs_alloc_request(mapping, file,
>  				   folio_file_pos(folio), folio_size(folio),
> @@ -460,7 +460,7 @@ int netfs_write_begin(struct netfs_inode *ctx,
>  		ret = PTR_ERR(rreq);
>  		goto error;
>  	}
> -	rreq->no_unlock_folio	= folio_index(folio);
> +	rreq->no_unlock_folio	= folio->index;
>  	__set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);
>  
>  	ret = netfs_begin_cache_read(rreq, ctx);
> @@ -518,7 +518,7 @@ int netfs_prefetch_for_write(struct file *file, struct folio *folio,
>  			     size_t offset, size_t len)
>  {
>  	struct netfs_io_request *rreq;
> -	struct address_space *mapping = folio_file_mapping(folio);
> +	struct address_space *mapping = folio->mapping;
>  	struct netfs_inode *ctx = netfs_inode(mapping->host);
>  	unsigned long long start = folio_pos(folio);
>  	size_t flen = folio_size(folio);
> @@ -535,7 +535,7 @@ int netfs_prefetch_for_write(struct file *file, struct folio *folio,
>  		goto error;
>  	}
>  
> -	rreq->no_unlock_folio = folio_index(folio);
> +	rreq->no_unlock_folio = folio->index;
>  	__set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);
>  	ret = netfs_begin_cache_read(rreq, ctx);
>  	if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
> diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
> index de517ca70d91..3afb1a0f92d1 100644
> --- a/fs/netfs/buffered_write.c
> +++ b/fs/netfs/buffered_write.c
> @@ -343,7 +343,7 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
>  			break;
>  		default:
>  			WARN(true, "Unexpected modify type %u ix=%lx\n",
> -			     howto, folio_index(folio));
> +			     howto, folio->index);
>  			ret = -EIO;
>  			goto error_folio_unlock;
>  		}
> @@ -648,7 +648,7 @@ static void netfs_pages_written_back(struct netfs_io_request *wreq)
>  	xas_for_each(&xas, folio, last) {
>  		WARN(!folio_test_writeback(folio),
>  		     "bad %zx @%llx page %lx %lx\n",
> -		     wreq->len, wreq->start, folio_index(folio), last);
> +		     wreq->len, wreq->start, folio->index, last);
>  
>  		if ((finfo = netfs_folio_info(folio))) {
>  			/* Streaming writes cannot be redirtied whilst under
> @@ -795,7 +795,7 @@ static void netfs_extend_writeback(struct address_space *mapping,
>  				continue;
>  			if (xa_is_value(folio))
>  				break;
> -			if (folio_index(folio) != index) {
> +			if (folio->index != index) {
>  				xas_reset(xas);
>  				break;
>  			}
> @@ -901,7 +901,7 @@ static ssize_t netfs_write_back_from_locked_folio(struct address_space *mapping,
>  	long count = wbc->nr_to_write;
>  	int ret;
>  
> -	_enter(",%lx,%llx-%llx,%u", folio_index(folio), start, end, caching);
> +	_enter(",%lx,%llx-%llx,%u", folio->index, start, end, caching);
>  
>  	wreq = netfs_alloc_request(mapping, NULL, start, folio_size(folio),
>  				   NETFS_WRITEBACK);
> @@ -1047,7 +1047,7 @@ static ssize_t netfs_writepages_begin(struct address_space *mapping,
>  
>  	start = folio_pos(folio); /* May regress with THPs */
>  
> -	_debug("wback %lx", folio_index(folio));
> +	_debug("wback %lx", folio->index);
>  
>  	/* At this point we hold neither the i_pages lock nor the page lock:
>  	 * the page may be truncated or invalidated (changing page->mapping to
> diff --git a/fs/netfs/io.c b/fs/netfs/io.c
> index 4309edf33862..e8ff1e61ce79 100644
> --- a/fs/netfs/io.c
> +++ b/fs/netfs/io.c
> @@ -124,7 +124,7 @@ static void netfs_rreq_unmark_after_write(struct netfs_io_request *rreq,
>  			/* We might have multiple writes from the same huge
>  			 * folio, but we mustn't unlock a folio more than once.
>  			 */
> -			if (have_unlocked && folio_index(folio) <= unlocked)
> +			if (have_unlocked && folio->index <= unlocked)
>  				continue;
>  			unlocked = folio_next_index(folio) - 1;
>  			trace_netfs_folio(folio, netfs_folio_trace_end_copy);
> diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c
> index 0e3af37fc924..90051ced8e2a 100644
> --- a/fs/netfs/misc.c
> +++ b/fs/netfs/misc.c
> @@ -180,7 +180,7 @@ void netfs_invalidate_folio(struct folio *folio, size_t offset, size_t length)
>  	struct netfs_folio *finfo = NULL;
>  	size_t flen = folio_size(folio);
>  
> -	_enter("{%lx},%zx,%zx", folio_index(folio), offset, length);
> +	_enter("{%lx},%zx,%zx", folio->index, offset, length);
>  
>  	folio_wait_fscache(folio);
>  
> 

Patch seems fine otherwise:

Reviewed-by: Jeff Layton <jlayton@kernel.org>