[PATCH 4/7] dax: Make dax_insert_mapping() return VM_FAULT_ state
From: Jan Kara <jack@suse.cz>
Date: 2017-07-27 13:12:50
Also in:
linux-ext4, linux-fsdevel, nvdimm
Subsystem:
filesystem direct access (dax), filesystems (vfs and infrastructure), the rest · Maintainers:
Dan Williams, Alexander Viro, Christian Brauner, Linus Torvalds
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 <jack@suse.cz> --- 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