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 02/13] mm: simplify generic_file_buffered_read_pagenotuptodate
Date: Sat, 31 Oct 2020 09:59:53 +0100 [thread overview]
Message-ID: <20201031090004.452516-3-hch@lst.de> (raw)
In-Reply-To: <20201031090004.452516-1-hch@lst.de>
Stop passing pointless arguments, and return an int instead of a page
struct that contains either the passed in page, an ERR_PTR or NULL and
use goto labels to share common code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
mm/filemap.c | 65 ++++++++++++++++++++++------------------------------
1 file changed, 28 insertions(+), 37 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index 2e997890cc81c2..c717cfe35cc72a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2217,15 +2217,11 @@ static int filemap_readpage(struct kiocb *iocb, struct page *page)
return error;
}
-static struct page *
-generic_file_buffered_read_pagenotuptodate(struct kiocb *iocb,
- struct file *filp,
- struct iov_iter *iter,
- struct page *page,
- loff_t pos, loff_t count)
+static int generic_file_buffered_read_pagenotuptodate(struct kiocb *iocb,
+ struct iov_iter *iter, struct page *page, loff_t pos,
+ loff_t count)
{
- struct address_space *mapping = filp->f_mapping;
- struct inode *inode = mapping->host;
+ struct address_space *mapping = iocb->ki_filp->f_mapping;
int error;
/*
@@ -2239,15 +2235,14 @@ generic_file_buffered_read_pagenotuptodate(struct kiocb *iocb,
} else {
error = wait_on_page_locked_killable(page);
}
- if (unlikely(error)) {
- put_page(page);
- return ERR_PTR(error);
- }
+ if (unlikely(error))
+ goto put_page;
+
if (PageUptodate(page))
- return page;
+ return 0;
- if (inode->i_blkbits == PAGE_SHIFT ||
- !mapping->a_ops->is_partially_uptodate)
+ 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)))
@@ -2260,38 +2255,33 @@ generic_file_buffered_read_pagenotuptodate(struct kiocb *iocb,
if (!mapping->a_ops->is_partially_uptodate(page,
pos & ~PAGE_MASK, count))
goto page_not_up_to_date_locked;
+
+unlock_page:
unlock_page(page);
- return page;
+ return 0;
page_not_up_to_date:
/* Get exclusive access to the page ... */
error = lock_page_for_iocb(iocb, page);
- if (unlikely(error)) {
- put_page(page);
- return ERR_PTR(error);
- }
+ if (unlikely(error))
+ goto put_page;
page_not_up_to_date_locked:
/* Did it get truncated before we got the lock? */
if (!page->mapping) {
unlock_page(page);
- put_page(page);
- return NULL;
+ error = AOP_TRUNCATED_PAGE;
+ goto put_page;
}
/* Did somebody else fill it already? */
- if (PageUptodate(page)) {
- unlock_page(page);
- return page;
- }
+ if (PageUptodate(page))
+ goto unlock_page;
+ return filemap_readpage(iocb, page);
- error = filemap_readpage(iocb, page);
- if (error) {
- if (error == AOP_TRUNCATED_PAGE)
- return NULL;
- return ERR_PTR(error);
- }
- return page;
+put_page:
+ put_page(page);
+ return error;
}
static struct page *
@@ -2395,13 +2385,14 @@ static int generic_file_buffered_read_get_pages(struct kiocb *iocb,
break;
}
- page = generic_file_buffered_read_pagenotuptodate(iocb,
- filp, iter, page, pg_pos, pg_count);
- if (IS_ERR_OR_NULL(page)) {
+ err = generic_file_buffered_read_pagenotuptodate(iocb,
+ iter, page, pg_pos, pg_count);
+ if (err) {
+ if (err == AOP_TRUNCATED_PAGE)
+ err = 0;
for (j = i + 1; j < nr_got; j++)
put_page(pages[j]);
nr_got = i;
- err = PTR_ERR_OR_ZERO(page);
break;
}
}
--
2.28.0
next prev parent reply other threads:[~2020-10-31 9:06 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 ` Christoph Hellwig [this message]
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 ` [PATCH 11/13] mm: streamline the partially uptodate checks in filemap_make_page_uptodate Christoph Hellwig
2020-11-01 11:23 ` 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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