| Message ID | 20220214174403.4147994-5-shr@fb.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Support sync buffered writes for io-uring | expand |
On Mon, Feb 14, 2022 at 09:43:53AM -0800, Stefan Roesch wrote: > @@ -1986,6 +1987,10 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, > gfp |= __GFP_WRITE; > if (fgp_flags & FGP_NOFS) > gfp &= ~__GFP_FS; > + if (fgp_flags & FGP_NOWAIT) { > + gfp |= GFP_ATOMIC; > + gfp &= ~__GFP_DIRECT_RECLAIM; > + } > > folio = filemap_alloc_folio(gfp, 0); No. FGP_NOWAIT means "Don't block on page lock". You can't redefine it to mean "Use GFP_ATOMIC" without changing all the existing callers. (Do not change the existing callers). __filemap_get_folio() already takes a gfp_t. There's no need for this.
diff --git a/mm/filemap.c b/mm/filemap.c index 0ff4278c3961..19065ad95a4c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -42,6 +42,7 @@ #include <linux/ramfs.h> #include <linux/page_idle.h> #include <linux/migrate.h> +#include <linux/sched/mm.h> #include <asm/pgalloc.h> #include <asm/tlbflush.h> #include "internal.h" @@ -1986,6 +1987,10 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, gfp |= __GFP_WRITE; if (fgp_flags & FGP_NOFS) gfp &= ~__GFP_FS; + if (fgp_flags & FGP_NOWAIT) { + gfp |= GFP_ATOMIC; + gfp &= ~__GFP_DIRECT_RECLAIM; + } folio = filemap_alloc_folio(gfp, 0); if (!folio) diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 749555a232a8..a1d05509b29f 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -136,6 +136,10 @@ struct page *grab_cache_page_write_begin(struct address_space *mapping, if (flags & AOP_FLAG_NOFS) fgp_flags |= FGP_NOFS; + + if (flags & AOP_FLAGS_NOWAIT) + fgp_flags |= FGP_NOWAIT; + return pagecache_get_page(mapping, index, fgp_flags, mapping_gfp_mask(mapping)); }
This adds support for async buffered writes in the mm layer. When the AOP_FLAGS_BUF_WASYNC flag is set, if the page is not already loaded, the page gets created without blocking on the allocation. Signed-off-by: Stefan Roesch <shr@fb.com> --- mm/filemap.c | 5 +++++ mm/folio-compat.c | 4 ++++ 2 files changed, 9 insertions(+)