The patch titled
Subject: mm/filemap: don't call ->readpage if IOCB_WAITQ is set
has been added to the -mm tree. Its filename is
mm-filemap-dont-call-readpage-if-iocb_waitq-is-set.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-filemap-dont-call-readpage-if-iocb_waitq-is-set.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-filemap-dont-call-readpage-if-iocb_waitq-is-set.patch
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there every 3-4 working days
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm/filemap: don't call ->readpage if IOCB_WAITQ is set
The readpage operation can block in many (most?) filesystems, so we should
punt to a work queue instead of calling it. This was the last caller of
lock_page_for_iocb(), so remove it.
Link: https://lkml.kernel.org/r/20210122160140.223228-9-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 | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)
--- a/mm/filemap.c~mm-filemap-dont-call-readpage-if-iocb_waitq-is-set
+++ a/mm/filemap.c
@@ -2148,16 +2148,6 @@ static void shrink_readahead_size_eio(st
ra->ra_pages /= 4;
}
-static int lock_page_for_iocb(struct kiocb *iocb, struct page *page)
-{
- if (iocb->ki_flags & IOCB_WAITQ)
- return lock_page_async(page, iocb->ki_waitq);
- else if (iocb->ki_flags & IOCB_NOWAIT)
- return trylock_page(page) ? 0 : -EAGAIN;
- else
- return lock_page_killable(page);
-}
-
/*
* filemap_get_read_batch - Get a batch of pages for read
*
@@ -2209,7 +2199,7 @@ static struct page *filemap_read_page(st
struct file_ra_state *ra = &filp->f_ra;
int error;
- if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT)) {
+ if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ)) {
unlock_page(page);
put_page(page);
return ERR_PTR(-EAGAIN);
@@ -2230,7 +2220,7 @@ static struct page *filemap_read_page(st
}
if (!PageUptodate(page)) {
- error = lock_page_for_iocb(iocb, page);
+ error = lock_page_killable(page);
if (unlikely(error)) {
put_page(page);
return ERR_PTR(error);
_
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
