From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
hch@lst.de, kent.overstreet@gmail.com
Subject: [PATCH v4 15/18] mm/filemap: Restructure filemap_get_pages
Date: Thu, 21 Jan 2021 04:16:13 +0000 [thread overview]
Message-ID: <20210121041616.3955703-16-willy@infradead.org> (raw)
In-Reply-To: <20210121041616.3955703-1-willy@infradead.org>
Remove the got_pages label, remove indentation, rename find_page to retry,
simplify error handling.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
---
mm/filemap.c | 71 +++++++++++++++++++++-------------------------------
1 file changed, 28 insertions(+), 43 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index f1c5c7d7aae8e..e09f0f1209a90 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2338,70 +2338,55 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
struct file_ra_state *ra = &filp->f_ra;
pgoff_t index = iocb->ki_pos >> PAGE_SHIFT;
pgoff_t last_index;
+ struct page *page;
int err = 0;
last_index = DIV_ROUND_UP(iocb->ki_pos + iter->count, PAGE_SIZE);
-find_page:
+retry:
if (fatal_signal_pending(current))
return -EINTR;
- filemap_get_read_batch(mapping, index, last_index, pvec);
- if (pvec->nr)
- goto got_pages;
-
- if (iocb->ki_flags & IOCB_NOIO)
- return -EAGAIN;
-
- page_cache_sync_readahead(mapping, ra, filp, index, last_index - index);
-
filemap_get_read_batch(mapping, index, last_index, pvec);
+ if (!pagevec_count(pvec)) {
+ if (iocb->ki_flags & IOCB_NOIO)
+ return -EAGAIN;
+ page_cache_sync_readahead(mapping, ra, filp, index,
+ last_index - index);
+ filemap_get_read_batch(mapping, index, last_index, pvec);
+ }
if (!pagevec_count(pvec)) {
if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_WAITQ))
return -EAGAIN;
err = filemap_create_page(filp, mapping,
iocb->ki_pos >> PAGE_SHIFT, pvec);
if (err == AOP_TRUNCATED_PAGE)
- goto find_page;
+ goto retry;
return err;
}
-got_pages:
- {
- struct page *page = pvec->pages[pvec->nr - 1];
-
- if (PageReadahead(page)) {
- err = filemap_readahead(iocb, filp, mapping, page,
- last_index);
- if (err) {
- put_page(page);
- pvec->nr--;
- goto err;
- }
- }
- if (!PageUptodate(page)) {
- if ((iocb->ki_flags & IOCB_WAITQ) &&
- pagevec_count(pvec) > 1)
- iocb->ki_flags |= IOCB_NOWAIT;
- err = filemap_update_page(iocb, mapping, iter, page);
- if (err) {
- if (err < 0)
- put_page(page);
- pvec->nr--;
- }
- }
+ page = pvec->pages[pagevec_count(pvec) - 1];
+ if (PageReadahead(page)) {
+ err = filemap_readahead(iocb, filp, mapping, page, last_index);
+ if (err)
+ goto err;
+ }
+ if (!PageUptodate(page)) {
+ if ((iocb->ki_flags & IOCB_WAITQ) && pagevec_count(pvec) > 1)
+ iocb->ki_flags |= IOCB_NOWAIT;
+ err = filemap_update_page(iocb, mapping, iter, page);
+ if (err)
+ goto err;
}
+ return 0;
err:
- if (likely(pvec->nr))
+ if (err < 0)
+ put_page(page);
+ if (likely(--pvec->nr))
return 0;
if (err == AOP_TRUNCATED_PAGE)
- goto find_page;
- if (err)
- return err;
- /*
- * No pages and no error means we raced and should retry:
- */
- goto find_page;
+ goto retry;
+ return err;
}
/**
--
2.29.2
next prev parent reply other threads:[~2021-01-21 4:32 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 4:15 [PATCH v4 00/18] Refactor generic_file_buffered_read Matthew Wilcox (Oracle)
2021-01-21 4:15 ` [PATCH v4 01/18] mm/filemap: Rename generic_file_buffered_read subfunctions Matthew Wilcox (Oracle)
2021-01-21 7:30 ` Christoph Hellwig
2021-01-21 8:23 ` Miaohe Lin
2021-01-21 4:16 ` [PATCH v4 02/18] mm/filemap: Remove dynamically allocated array from filemap_read Matthew Wilcox (Oracle)
2021-01-21 7:31 ` Christoph Hellwig
2021-01-22 6:59 ` Miaohe Lin
2021-01-21 4:16 ` [PATCH v4 03/18] mm/filemap: Convert filemap_get_pages to take a pagevec Matthew Wilcox (Oracle)
2021-01-21 7:31 ` Christoph Hellwig
2021-01-21 4:16 ` [PATCH v4 04/18] mm/filemap: Use head pages in generic_file_buffered_read Matthew Wilcox (Oracle)
2021-01-21 4:16 ` [PATCH v4 05/18] mm/filemap: Pass a sleep state to put_and_wait_on_page_locked Matthew Wilcox (Oracle)
2021-01-21 4:16 ` [PATCH v4 06/18] mm/filemap: Support readpage splitting a page Matthew Wilcox (Oracle)
2021-01-21 4:16 ` [PATCH v4 07/18] mm/filemap: Inline __wait_on_page_locked_async into caller Matthew Wilcox (Oracle)
2021-01-21 4:16 ` [PATCH v4 08/18] mm/filemap: Don't call ->readpage if IOCB_WAITQ is set Matthew Wilcox (Oracle)
2021-01-21 4:16 ` [PATCH v4 09/18] mm/filemap: Change filemap_read_page calling conventions Matthew Wilcox (Oracle)
2021-01-21 7:31 ` Christoph Hellwig
2021-01-21 4:16 ` [PATCH v4 10/18] mm/filemap: Change filemap_create_page " Matthew Wilcox (Oracle)
2021-01-21 4:16 ` [PATCH v4 11/18] mm/filemap: Convert filemap_update_page to return an errno Matthew Wilcox (Oracle)
2021-01-21 7:32 ` Christoph Hellwig
2021-01-21 4:16 ` [PATCH v4 12/18] mm/filemap: Move the iocb checks into filemap_update_page Matthew Wilcox (Oracle)
2021-01-21 4:16 ` [PATCH v4 13/18] mm/filemap: Add filemap_range_uptodate Matthew Wilcox (Oracle)
2021-01-21 7:32 ` Christoph Hellwig
2021-01-21 4:16 ` [PATCH v4 14/18] mm/filemap: Split filemap_readahead out of filemap_get_pages Matthew Wilcox (Oracle)
2021-01-21 7:33 ` Christoph Hellwig
2021-01-21 4:16 ` Matthew Wilcox (Oracle) [this message]
2021-01-21 7:33 ` [PATCH v4 15/18] mm/filemap: Restructure filemap_get_pages Christoph Hellwig
2021-01-21 4:16 ` [PATCH v4 16/18] mm/filemap: Don't relock the page after calling readpage Matthew Wilcox (Oracle)
2021-01-21 7:34 ` Christoph Hellwig
2021-01-21 4:16 ` [PATCH v4 17/18] mm/filemap: Rename generic_file_buffered_read to filemap_read Matthew Wilcox (Oracle)
2021-01-21 4:16 ` [PATCH v4 18/18] mm/filemap: Simplify generic_file_read_iter Matthew Wilcox (Oracle)
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