The patch titled
Subject: mm/filemap: convert filemap_update_page to return an errno
has been added to the -mm tree. Its filename is
mm-filemap-convert-filemap_update_page-to-return-an-errno.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-filemap-convert-filemap_update_page-to-return-an-errno.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-filemap-convert-filemap_update_page-to-return-an-errno.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm/filemap: convert filemap_update_page to return an errno
Use AOP_TRUNCATED_PAGE to indicate that no error occurred, but the page we
looked up is no longer valid. In this case, the reference to the page
will have been removed; if we hit any other error, the caller will release
the reference.
Link: https://lkml.kernel.org/r/20210122160140.223228-12-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 38 +++++++++++++++++---------------------
1 file changed, 17 insertions(+), 21 deletions(-)
--- a/mm/filemap.c~mm-filemap-convert-filemap_update_page-to-return-an-errno
+++ a/mm/filemap.c
@@ -2227,24 +2227,21 @@ static int filemap_read_page(struct file
return error;
}
-static struct page *filemap_update_page(struct kiocb *iocb, struct file *filp,
- struct iov_iter *iter, struct page *page, loff_t pos,
- loff_t 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 address_space *mapping = filp->f_mapping;
struct inode *inode = mapping->host;
int error;
if (iocb->ki_flags & IOCB_WAITQ) {
error = lock_page_async(page, iocb->ki_waitq);
- if (error) {
- put_page(page);
- return ERR_PTR(error);
- }
+ if (error)
+ return error;
} else {
if (!trylock_page(page)) {
put_and_wait_on_page_locked(page, TASK_KILLABLE);
- return NULL;
+ return AOP_TRUNCATED_PAGE;
}
}
@@ -2263,25 +2260,21 @@ static struct page *filemap_update_page(
goto readpage;
uptodate:
unlock_page(page);
- return page;
+ return 0;
readpage:
if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ)) {
unlock_page(page);
- put_page(page);
- return ERR_PTR(-EAGAIN);
+ return -EAGAIN;
}
error = filemap_read_page(iocb->ki_filp, mapping, page);
- if (!error)
- return page;
- put_page(page);
if (error == AOP_TRUNCATED_PAGE)
- return NULL;
- return ERR_PTR(error);
+ put_page(page);
+ return error;
truncated:
unlock_page(page);
put_page(page);
- return NULL;
+ return AOP_TRUNCATED_PAGE;
}
static int filemap_create_page(struct file *file,
@@ -2375,11 +2368,12 @@ got_pages:
goto err;
}
- page = filemap_update_page(iocb, filp, iter, page,
+ err = filemap_update_page(iocb, mapping, iter, page,
pg_pos, pg_count);
- if (IS_ERR_OR_NULL(page)) {
+ if (err) {
+ if (err < 0)
+ put_page(page);
pvec->nr--;
- err = PTR_ERR_OR_ZERO(page);
}
}
}
@@ -2387,6 +2381,8 @@ got_pages:
err:
if (likely(pvec->nr))
return 0;
+ if (err == AOP_TRUNCATED_PAGE)
+ goto find_page;
if (err)
return err;
/*
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-debug-improve-memcg-debugging.patch
mm-filemap-rename-generic_file_buffered_read-subfunctions.patch
mm-filemap-remove-dynamically-allocated-array-from-filemap_read.patch
mm-filemap-convert-filemap_get_pages-to-take-a-pagevec.patch
mm-filemap-use-head-pages-in-generic_file_buffered_read.patch
mm-filemap-pass-a-sleep-state-to-put_and_wait_on_page_locked.patch
mm-filemap-support-readpage-splitting-a-page.patch
mm-filemap-inline-__wait_on_page_locked_async-into-caller.patch
mm-filemap-dont-call-readpage-if-iocb_waitq-is-set.patch
mm-filemap-change-filemap_read_page-calling-conventions.patch
mm-filemap-change-filemap_create_page-calling-conventions.patch
mm-filemap-convert-filemap_update_page-to-return-an-errno.patch
mm-filemap-move-the-iocb-checks-into-filemap_update_page.patch
mm-filemap-add-filemap_range_uptodate.patch
mm-filemap-split-filemap_readahead-out-of-filemap_get_pages.patch
mm-filemap-restructure-filemap_get_pages.patch
mm-filemap-dont-relock-the-page-after-calling-readpage.patch
mm-make-pagecache-tagged-lookups-return-only-head-pages.patch
mm-shmem-use-pagevec_lookup-in-shmem_unlock_mapping.patch
mm-swap-optimise-get_shadow_from_swap_cache.patch
mm-add-fgp_entry.patch
mm-filemap-rename-find_get_entry-to-mapping_get_entry.patch
mm-filemap-add-helper-for-finding-pages.patch
mm-filemap-add-helper-for-finding-pages-fix.patch
mm-filemap-add-mapping_seek_hole_data.patch
mm-filemap-add-mapping_seek_hole_data-fix.patch
iomap-use-mapping_seek_hole_data.patch
mm-add-and-use-find_lock_entries.patch
mm-add-and-use-find_lock_entries-fix.patch
mm-add-an-end-parameter-to-find_get_entries.patch
mm-add-an-end-parameter-to-pagevec_lookup_entries.patch
mm-remove-nr_entries-parameter-from-pagevec_lookup_entries.patch
mm-pass-pvec-directly-to-find_get_entries.patch
mm-remove-pagevec_lookup_entries.patch
