From patchwork Fri Oct 14 23:57:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 13007472 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 004CC4695 for ; Fri, 14 Oct 2022 23:57:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1665791879; x=1697327879; h=subject:from:to:cc:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dRBEo+va9LdTaMALBHzem55il8qhSDS6I2rVZ6WlqEM=; b=gTjy+6SZp0N1E6u1YhLAzDKJDAYCwfZjo18sdITKimPojITSQhYCNbox EDLltESVjwzhHmQ/KONf7iQdVdJ0gIFWMla9D72YVrWPr1Q2TJj0CfbA7 mh7EXtoB7Bv5f2yg8Ci11OrLZFm1m7WcajvAzFEknPLZdJ12snc/ymB8X lN8P0mYaOUBft4Nq2+L4trDPkyrpkS7cU/tzauVeQJ3Vv/gLKMCKGENIB RiMkmVnSyiV4CmXa1HhBck5YgwO5g0aNRv18v+AKKNLAk5a4rs5A0Kh9O RCmJ6IfYicJeROgeyc3GS5wLF6VXgrkHfcy5jkFZEihXSDIvHjC1j6TXq g==; X-IronPort-AV: E=McAfee;i="6500,9779,10500"; a="367523132" X-IronPort-AV: E=Sophos;i="5.95,185,1661842800"; d="scan'208";a="367523132" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Oct 2022 16:57:44 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10500"; a="630113300" X-IronPort-AV: E=Sophos;i="5.95,185,1661842800"; d="scan'208";a="630113300" Received: from uyoon-mobl.amr.corp.intel.com (HELO dwillia2-xfh.jf.intel.com) ([10.209.90.112]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Oct 2022 16:57:43 -0700 Subject: [PATCH v3 08/25] fsdax: Update dax_insert_entry() calling convention to return an error From: Dan Williams To: linux-mm@kvack.org Cc: Matthew Wilcox , Jan Kara , "Darrick J. Wong" , Jason Gunthorpe , Christoph Hellwig , John Hubbard , david@fromorbit.com, nvdimm@lists.linux.dev, akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org Date: Fri, 14 Oct 2022 16:57:43 -0700 Message-ID: <166579186334.2236710.388332274317019999.stgit@dwillia2-xfh.jf.intel.com> In-Reply-To: <166579181584.2236710.17813547487183983273.stgit@dwillia2-xfh.jf.intel.com> References: <166579181584.2236710.17813547487183983273.stgit@dwillia2-xfh.jf.intel.com> User-Agent: StGit/0.18-3-g996c Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In preparation for teaching dax_insert_entry() to take live @pgmap references, enable it to return errors. Given the observation that all callers overwrite the passed in entry with the return value, just update @entry in place and convert the return code to a vm_fault_t status. Cc: Matthew Wilcox Cc: Jan Kara Cc: "Darrick J. Wong" Cc: Jason Gunthorpe Cc: Christoph Hellwig Cc: John Hubbard Signed-off-by: Dan Williams --- fs/dax.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 6990a6e7df9f..1f6c1abfe0c9 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -907,14 +907,15 @@ static bool dax_fault_is_cow(const struct iomap_iter *iter) * already in the tree, we will skip the insertion and just dirty the PMD as * appropriate. */ -static void *dax_insert_entry(struct xa_state *xas, struct vm_fault *vmf, - const struct iomap_iter *iter, void *entry, pfn_t pfn, - unsigned long flags) +static vm_fault_t dax_insert_entry(struct xa_state *xas, struct vm_fault *vmf, + const struct iomap_iter *iter, void **pentry, + pfn_t pfn, unsigned long flags) { struct address_space *mapping = vmf->vma->vm_file->f_mapping; void *new_entry = dax_make_entry(pfn, flags); bool dirty = !dax_fault_is_synchronous(iter, vmf->vma); bool cow = dax_fault_is_cow(iter); + void *entry = *pentry; if (dirty) __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); @@ -960,7 +961,9 @@ static void *dax_insert_entry(struct xa_state *xas, struct vm_fault *vmf, xas_set_mark(xas, PAGECACHE_TAG_TOWRITE); xas_unlock_irq(xas); - return entry; + + *pentry = entry; + return 0; } static int dax_writeback_one(struct xa_state *xas, struct dax_device *dax_dev, @@ -1206,9 +1209,12 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, struct vm_fault *vmf, pfn_t pfn = pfn_to_pfn_t(my_zero_pfn(vaddr)); vm_fault_t ret; - *entry = dax_insert_entry(xas, vmf, iter, *entry, pfn, DAX_ZERO_PAGE); + ret = dax_insert_entry(xas, vmf, iter, entry, pfn, DAX_ZERO_PAGE); + if (ret) + goto out; ret = vmf_insert_mixed(vmf->vma, vaddr, pfn); +out: trace_dax_load_hole(inode, vmf, ret); return ret; } @@ -1225,6 +1231,7 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, struct page *zero_page; spinlock_t *ptl; pmd_t pmd_entry; + vm_fault_t ret; pfn_t pfn; zero_page = mm_get_huge_zero_page(vmf->vma->vm_mm); @@ -1233,8 +1240,10 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, goto fallback; pfn = page_to_pfn_t(zero_page); - *entry = dax_insert_entry(xas, vmf, iter, *entry, pfn, - DAX_PMD | DAX_ZERO_PAGE); + ret = dax_insert_entry(xas, vmf, iter, entry, pfn, + DAX_PMD | DAX_ZERO_PAGE); + if (ret) + return ret; if (arch_needs_pgtable_deposit()) { pgtable = pte_alloc_one(vma->vm_mm); @@ -1587,6 +1596,7 @@ static vm_fault_t dax_fault_iter(struct vm_fault *vmf, bool write = iter->flags & IOMAP_WRITE; unsigned long entry_flags = pmd ? DAX_PMD : 0; int err = 0, id; + vm_fault_t ret; pfn_t pfn; void *kaddr; @@ -1613,8 +1623,10 @@ static vm_fault_t dax_fault_iter(struct vm_fault *vmf, return pmd ? VM_FAULT_FALLBACK : dax_fault_return(err); } - *entry = dax_insert_entry(xas, vmf, iter, *entry, pfn, entry_flags); + ret = dax_insert_entry(xas, vmf, iter, entry, pfn, entry_flags); dax_read_unlock(id); + if (ret) + return ret; if (write && srcmap->type != IOMAP_HOLE && srcmap->addr != iomap->addr) {