From: Jan Kara Subject: [PATCH 4/7] dax: Make dax_insert_mapping() return VM_FAULT_ state Date: Thu, 27 Jul 2017 15:12:42 +0200 Message-ID: <20170727131245.28279-5-jack@suse.cz> References: <20170727131245.28279-1-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Christoph Hellwig , Jan Kara , linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, Dave Chinner , linux-xfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andy Lutomirski , linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Return-path: In-Reply-To: <20170727131245.28279-1-jack-AlSwsSmVLrQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" List-Id: linux-ext4.vger.kernel.org Currently dax_insert_mapping() returns normal error code which is later converted to VM_FAULT_ state. Since we will need to do more state modifications specific to dax_insert_mapping() it does not make sense to push them up to the caller of dax_insert_mapping(). Instead make dax_insert_mapping() return VM_FAULT_ state the same way as dax_pmd_insert_mapping() does that. Signed-off-by: Jan Kara --- fs/dax.c | 45 +++++++++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 20 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 0673efd72f53..9658975b926a 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -814,6 +814,15 @@ int dax_writeback_mapping_range(struct address_space *mapping, } EXPORT_SYMBOL_GPL(dax_writeback_mapping_range); +static int dax_fault_return(int error) +{ + if (error == 0) + return VM_FAULT_NOPAGE; + if (error == -ENOMEM) + return VM_FAULT_OOM; + return VM_FAULT_SIGBUS; +} + static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos) { return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9); @@ -828,7 +837,7 @@ static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap, unsigned long vaddr = vmf->address; void *ret, *kaddr; pgoff_t pgoff; - int id, rc; + int id, rc, vmf_ret; pfn_t pfn; rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff); @@ -850,9 +859,18 @@ static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap, trace_dax_insert_mapping(mapping->host, vmf, ret); if (vmf->flags & FAULT_FLAG_WRITE) - return vm_insert_mixed_mkwrite(vma, vaddr, pfn); + rc = vm_insert_mixed_mkwrite(vma, vaddr, pfn); else - return vm_insert_mixed(vma, vaddr, pfn); + rc = vm_insert_mixed(vma, vaddr, pfn); + + /* -EBUSY is fine, somebody else faulted on the same PTE */ + if (rc == -EBUSY) + rc = 0; + + vmf_ret = dax_fault_return(rc); + if (iomap->flags & IOMAP_F_NEW) + vmf_ret |= VM_FAULT_MAJOR; + return vmf_ret; } /* @@ -1062,15 +1080,6 @@ dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, } EXPORT_SYMBOL_GPL(dax_iomap_rw); -static int dax_fault_return(int error) -{ - if (error == 0) - return VM_FAULT_NOPAGE; - if (error == -ENOMEM) - return VM_FAULT_OOM; - return VM_FAULT_SIGBUS; -} - static int dax_iomap_pte_fault(struct vm_fault *vmf, bool sync, const struct iomap_ops *ops) { @@ -1080,7 +1089,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, bool sync, loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; struct iomap iomap = { 0 }; unsigned flags = IOMAP_FAULT; - int error, major = 0; + int error; int vmf_ret = 0; void *entry; @@ -1163,13 +1172,9 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, bool sync, if (iomap.flags & IOMAP_F_NEW) { count_vm_event(PGMAJFAULT); count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT); - major = VM_FAULT_MAJOR; } - error = dax_insert_mapping(vmf, &iomap, pos, entry); - /* -EBUSY is fine, somebody else faulted on the same PTE */ - if (error == -EBUSY) - error = 0; - break; + vmf_ret = dax_insert_mapping(vmf, &iomap, pos, entry); + goto finish_iomap; case IOMAP_UNWRITTEN: case IOMAP_HOLE: if (!(vmf->flags & FAULT_FLAG_WRITE)) { @@ -1184,7 +1189,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, bool sync, } error_finish_iomap: - vmf_ret = dax_fault_return(error) | major; + vmf_ret = dax_fault_return(error); finish_iomap: if (ops->iomap_end) { int copied = PAGE_SIZE; -- 2.12.3