From 5c075c5b8fc4ebc34aac188be4eccc238521eb6f Mon Sep 17 00:00:00 2001 From: "Fabio M. De Francesco" Date: Fri, 9 Jun 2023 16:59:37 +0200 Subject: fs/aio: Stop allocating aio rings from HIGHMEM There is no need to allocate aio rings from HIGHMEM because of very little memory needed here. Therefore, use GFP_USER flag in find_or_create_page() and get rid of kmap*() mappings. Cc: Al Viro Cc: Ira Weiny Suggested-by: Matthew Wilcox Signed-off-by: Fabio M. De Francesco Reviewed-by: Ira Weiny Message-Id: <20230609145937.17610-1-fmdefrancesco@gmail.com> Signed-off-by: Christian Brauner --- fs/aio.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-) (limited to 'fs/aio.c') diff --git a/fs/aio.c b/fs/aio.c index b0b17bd098bb..77e33619de40 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -530,7 +530,7 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events) for (i = 0; i < nr_pages; i++) { struct page *page; page = find_or_create_page(file->f_mapping, - i, GFP_HIGHUSER | __GFP_ZERO); + i, GFP_USER | __GFP_ZERO); if (!page) break; pr_debug("pid(%d) page[%d]->count=%d\n", @@ -571,7 +571,7 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events) ctx->user_id = ctx->mmap_base; ctx->nr_events = nr_events; /* trusted copy */ - ring = kmap_atomic(ctx->ring_pages[0]); + ring = page_address(ctx->ring_pages[0]); ring->nr = nr_events; /* user copy */ ring->id = ~0U; ring->head = ring->tail = 0; @@ -579,7 +579,6 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events) ring->compat_features = AIO_RING_COMPAT_FEATURES; ring->incompat_features = AIO_RING_INCOMPAT_FEATURES; ring->header_length = sizeof(struct aio_ring); - kunmap_atomic(ring); flush_dcache_page(ctx->ring_pages[0]); return 0; @@ -682,9 +681,8 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm) * we are protected from page migration * changes ring_pages by ->ring_lock. */ - ring = kmap_atomic(ctx->ring_pages[0]); + ring = page_address(ctx->ring_pages[0]); ring->id = ctx->id; - kunmap_atomic(ring); return 0; } @@ -1025,9 +1023,8 @@ static void user_refill_reqs_available(struct kioctx *ctx) * against ctx->completed_events below will make sure we do the * safe/right thing. */ - ring = kmap_atomic(ctx->ring_pages[0]); + ring = page_address(ctx->ring_pages[0]); head = ring->head; - kunmap_atomic(ring); refill_reqs_available(ctx, head, ctx->tail); } @@ -1133,12 +1130,11 @@ static void aio_complete(struct aio_kiocb *iocb) if (++tail >= ctx->nr_events) tail = 0; - ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]); + ev_page = page_address(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]); event = ev_page + pos % AIO_EVENTS_PER_PAGE; *event = iocb->ki_res; - kunmap_atomic(ev_page); flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]); pr_debug("%p[%u]: %p: %p %Lx %Lx %Lx\n", ctx, tail, iocb, @@ -1152,10 +1148,9 @@ static void aio_complete(struct aio_kiocb *iocb) ctx->tail = tail; - ring = kmap_atomic(ctx->ring_pages[0]); + ring = page_address(ctx->ring_pages[0]); head = ring->head; ring->tail = tail; - kunmap_atomic(ring); flush_dcache_page(ctx->ring_pages[0]); ctx->completed_events++; @@ -1215,10 +1210,9 @@ static long aio_read_events_ring(struct kioctx *ctx, mutex_lock(&ctx->ring_lock); /* Access to ->ring_pages here is protected by ctx->ring_lock. */ - ring = kmap_atomic(ctx->ring_pages[0]); + ring = page_address(ctx->ring_pages[0]); head = ring->head; tail = ring->tail; - kunmap_atomic(ring); /* * Ensure that once we've read the current tail pointer, that @@ -1250,10 +1244,9 @@ static long aio_read_events_ring(struct kioctx *ctx, avail = min(avail, nr - ret); avail = min_t(long, avail, AIO_EVENTS_PER_PAGE - pos); - ev = kmap(page); + ev = page_address(page); copy_ret = copy_to_user(event + ret, ev + pos, sizeof(*ev) * avail); - kunmap(page); if (unlikely(copy_ret)) { ret = -EFAULT; @@ -1265,9 +1258,8 @@ static long aio_read_events_ring(struct kioctx *ctx, head %= ctx->nr_events; } - ring = kmap_atomic(ctx->ring_pages[0]); + ring = page_address(ctx->ring_pages[0]); ring->head = head; - kunmap_atomic(ring); flush_dcache_page(ctx->ring_pages[0]); pr_debug("%li h%u t%u\n", ret, head, tail); -- cgit