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authorMatthew Wilcox (Oracle) <willy@infradead.org>2021-02-24 21:02:28 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-24 22:38:28 +0100
commitfce70da3a80fcd0a9c0192dedd6bf86a43845ac9 (patch)
treece139414787cb026d4a5305d4ddc808c95eda252 /mm/filemap.c
parentmm/filemap: move the iocb checks into filemap_update_page (diff)
downloadlinux-fce70da3a80fcd0a9c0192dedd6bf86a43845ac9.tar.xz
linux-fce70da3a80fcd0a9c0192dedd6bf86a43845ac9.zip
mm/filemap: add filemap_range_uptodate
Move the complicated condition and the calculations out of filemap_update_page() into its own function. [willy@infradead.org: unlock page before dropping its refcount] Link: https://lkml.kernel.org/r/20210201125229.GO308988@casper.infradead.org Link: https://lkml.kernel.org/r/20210122160140.223228-14-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/filemap.c')
-rw-r--r--mm/filemap.c65
1 files changed, 39 insertions, 26 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index cd863c4ff9ae..1eaafc9402e0 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2233,11 +2233,36 @@ static int filemap_read_page(struct file *file, struct address_space *mapping,
return error;
}
+static bool filemap_range_uptodate(struct address_space *mapping,
+ loff_t pos, struct iov_iter *iter, struct page *page)
+{
+ int count;
+
+ if (PageUptodate(page))
+ return true;
+ /* pipes can't handle partially uptodate pages */
+ if (iov_iter_is_pipe(iter))
+ return false;
+ if (!mapping->a_ops->is_partially_uptodate)
+ return false;
+ if (mapping->host->i_blkbits >= (PAGE_SHIFT + thp_order(page)))
+ return false;
+
+ count = iter->count;
+ if (page_offset(page) > pos) {
+ count -= page_offset(page) - pos;
+ pos = 0;
+ } else {
+ pos -= page_offset(page);
+ }
+
+ return mapping->a_ops->is_partially_uptodate(page, pos, count);
+}
+
static int filemap_update_page(struct kiocb *iocb,
struct address_space *mapping, struct iov_iter *iter,
- struct page *page, loff_t pos, loff_t count)
+ struct page *page)
{
- struct inode *inode = mapping->host;
int error;
if (!trylock_page(page)) {
@@ -2254,26 +2279,15 @@ static int filemap_update_page(struct kiocb *iocb,
if (!page->mapping)
goto truncated;
- if (PageUptodate(page))
- goto uptodate;
- if (inode->i_blkbits == PAGE_SHIFT ||
- !mapping->a_ops->is_partially_uptodate)
- goto readpage;
- /* pipes can't handle partially uptodate pages */
- if (unlikely(iov_iter_is_pipe(iter)))
- goto readpage;
- if (!mapping->a_ops->is_partially_uptodate(page,
- pos & (thp_size(page) - 1), count))
- goto readpage;
-uptodate:
- unlock_page(page);
- return 0;
-readpage:
- if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ)) {
- unlock_page(page);
- return -EAGAIN;
- }
+ error = 0;
+ if (filemap_range_uptodate(mapping, iocb->ki_pos, iter, page))
+ goto unlock;
+
+ error = -EAGAIN;
+ if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ))
+ goto unlock;
+
error = filemap_read_page(iocb->ki_filp, mapping, page);
if (error == AOP_TRUNCATED_PAGE)
put_page(page);
@@ -2282,6 +2296,9 @@ truncated:
unlock_page(page);
put_page(page);
return AOP_TRUNCATED_PAGE;
+unlock:
+ unlock_page(page);
+ return error;
}
static int filemap_create_page(struct file *file,
@@ -2351,9 +2368,6 @@ got_pages:
{
struct page *page = pvec->pages[pvec->nr - 1];
pgoff_t pg_index = page->index;
- loff_t pg_pos = max(iocb->ki_pos,
- (loff_t) pg_index << PAGE_SHIFT);
- loff_t pg_count = iocb->ki_pos + iter->count - pg_pos;
if (PageReadahead(page)) {
if (iocb->ki_flags & IOCB_NOIO) {
@@ -2370,8 +2384,7 @@ got_pages:
if ((iocb->ki_flags & IOCB_WAITQ) &&
pagevec_count(pvec) > 1)
iocb->ki_flags |= IOCB_NOWAIT;
- err = filemap_update_page(iocb, mapping, iter, page,
- pg_pos, pg_count);
+ err = filemap_update_page(iocb, mapping, iter, page);
if (err) {
if (err < 0)
put_page(page);