From: Christoph Hellwig <hch@lst.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>,
Matthew Wilcox <willy@infradead.org>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH 11/13] mm: streamline the partially uptodate checks in filemap_make_page_uptodate
Date: Sat, 31 Oct 2020 10:00:02 +0100 [thread overview]
Message-ID: <20201031090004.452516-12-hch@lst.de> (raw)
In-Reply-To: <20201031090004.452516-1-hch@lst.de>
Unwind the goto mess a bit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
mm/filemap.c | 42 +++++++++++++++++-------------------------
1 file changed, 17 insertions(+), 25 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index 000f75cd359d1c..904b0a4fb9e008 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2218,7 +2218,6 @@ static int filemap_make_page_uptodate(struct kiocb *iocb, struct iov_iter *iter,
struct address_space *mapping = file->f_mapping;
loff_t last = iocb->ki_pos + iter->count;
pgoff_t last_index = (last + PAGE_SIZE - 1) >> PAGE_SHIFT;
- loff_t pos = max(iocb->ki_pos, (loff_t)pg_index << PAGE_SHIFT);
int error;
if (PageReadahead(page)) {
@@ -2251,32 +2250,22 @@ static int filemap_make_page_uptodate(struct kiocb *iocb, struct iov_iter *iter,
if (PageUptodate(page))
return 0;
- if (mapping->host->i_blkbits == PAGE_SHIFT ||
- !mapping->a_ops->is_partially_uptodate)
- goto page_not_up_to_date;
- /* pipes can't handle partially uptodate pages */
- if (unlikely(iov_iter_is_pipe(iter)))
- goto page_not_up_to_date;
- if (!trylock_page(page))
- goto page_not_up_to_date;
- /* Did it get truncated before we got the lock? */
- if (!page->mapping)
- goto page_not_up_to_date_locked;
- if (!mapping->a_ops->is_partially_uptodate(page, pos & ~PAGE_MASK,
- last - pos))
- goto page_not_up_to_date_locked;
-
-unlock_page:
- unlock_page(page);
- return 0;
+ if (mapping->host->i_blkbits <= PAGE_SHIFT &&
+ mapping->a_ops->is_partially_uptodate &&
+ !iov_iter_is_pipe(iter) &&
+ trylock_page(page)) {
+ loff_t pos = max(iocb->ki_pos, (loff_t)pg_index << PAGE_SHIFT);
-page_not_up_to_date:
- /* Get exclusive access to the page ... */
- error = lock_page_for_iocb(iocb, page);
- if (unlikely(error))
- return error;
+ if (page->mapping &&
+ mapping->a_ops->is_partially_uptodate(page,
+ pos & ~PAGE_MASK, last - pos))
+ goto unlock_page;
+ } else {
+ error = lock_page_for_iocb(iocb, page);
+ if (unlikely(error))
+ return error;
+ }
-page_not_up_to_date_locked:
/* Did it get truncated before we got the lock? */
if (!page->mapping) {
unlock_page(page);
@@ -2287,6 +2276,9 @@ static int filemap_make_page_uptodate(struct kiocb *iocb, struct iov_iter *iter,
if (PageUptodate(page))
goto unlock_page;
return filemap_readpage(iocb, page);
+unlock_page:
+ unlock_page(page);
+ return 0;
}
static int filemap_new_page(struct kiocb *iocb, struct iov_iter *iter,
--
2.28.0
next prev parent reply other threads:[~2020-10-31 9:26 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-31 8:59 clean up the generic pagecache read helpers Christoph Hellwig
2020-10-31 8:59 ` [PATCH 01/13] mm: simplify generic_file_buffered_read_readpage Christoph Hellwig
2020-10-31 8:59 ` [PATCH 02/13] mm: simplify generic_file_buffered_read_pagenotuptodate Christoph Hellwig
2020-10-31 8:59 ` [PATCH 03/13] mm: lift the nowait checks into generic_file_buffered_read_pagenotuptodate Christoph Hellwig
2020-10-31 8:59 ` [PATCH 04/13] mm: handle readahead in generic_file_buffered_read_pagenotuptodate Christoph Hellwig
2020-10-31 17:06 ` Matthew Wilcox
2020-11-01 10:31 ` Christoph Hellwig
2020-11-01 10:49 ` Matthew Wilcox
2020-11-01 10:51 ` Christoph Hellwig
2020-11-01 10:51 ` Christoph Hellwig
2020-11-01 11:04 ` Matthew Wilcox
2020-11-01 11:52 ` Christoph Hellwig
2020-11-01 14:55 ` Matthew Wilcox
2020-11-02 8:18 ` Christoph Hellwig
2020-10-31 8:59 ` [PATCH 05/13] mm: simplify generic_file_buffered_read_no_cached_page Christoph Hellwig
2020-10-31 16:20 ` Matthew Wilcox
2020-10-31 16:28 ` Matthew Wilcox
2020-11-01 10:29 ` Christoph Hellwig
2020-10-31 8:59 ` [PATCH 06/13] mm: factor out a filemap_find_get_pages helper Christoph Hellwig
2020-10-31 8:59 ` [PATCH 07/13] mm: refactor generic_file_buffered_read_get_pages Christoph Hellwig
2020-11-01 11:18 ` Matthew Wilcox
2020-10-31 8:59 ` [PATCH 08/13] mm: move putting the page on error out of filemap_readpage Christoph Hellwig
2020-10-31 9:00 ` [PATCH 09/13] mm: move putting the page on error out of filemap_make_page_uptodate Christoph Hellwig
2020-10-31 9:00 ` [PATCH 10/13] mm: open code readahead in filemap_new_page Christoph Hellwig
2020-11-01 11:20 ` Matthew Wilcox
2020-10-31 9:00 ` Christoph Hellwig [this message]
2020-11-01 11:23 ` [PATCH 11/13] mm: streamline the partially uptodate checks in filemap_make_page_uptodate Matthew Wilcox
2020-10-31 9:00 ` [PATCH 12/13] mm: rename generic_file_buffered_read to filemap_read Christoph Hellwig
2020-10-31 9:00 ` [PATCH 13/13] mm: simplify generic_file_read_iter Christoph Hellwig
2020-10-31 15:42 ` clean up the generic pagecache read helpers Matthew Wilcox
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