diff options
| -rw-r--r-- | fs/dax.c | 193 |
1 files changed, 75 insertions, 118 deletions
@@ -1010,7 +1010,7 @@ static sector_t dax_iomap_sector(const struct iomap *iomap, loff_t pos) return (iomap->addr + (pos & PAGE_MASK) - iomap->offset) >> 9; } -static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size, +static int dax_iomap_pfn(const struct iomap *iomap, loff_t pos, size_t size, pfn_t *pfnp) { const sector_t sector = dax_iomap_sector(iomap, pos); @@ -1068,7 +1068,7 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, #ifdef CONFIG_FS_DAX_PMD static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, - struct iomap *iomap, void **entry) + const struct iomap *iomap, void **entry) { struct address_space *mapping = vmf->vma->vm_file->f_mapping; unsigned long pmd_addr = vmf->address & PMD_MASK; @@ -1120,7 +1120,7 @@ fallback: } #else static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, - struct iomap *iomap, void **entry) + const struct iomap *iomap, void **entry) { return VM_FAULT_FALLBACK; } @@ -1309,7 +1309,7 @@ static vm_fault_t dax_fault_return(int error) * flushed on write-faults (non-cow), but not read-faults. */ static bool dax_fault_is_synchronous(unsigned long flags, - struct vm_area_struct *vma, struct iomap *iomap) + struct vm_area_struct *vma, const struct iomap *iomap) { return (flags & IOMAP_WRITE) && (vma->vm_flags & VM_SYNC) && (iomap->flags & IOMAP_F_DIRTY); @@ -1329,22 +1329,22 @@ static vm_fault_t dax_fault_synchronous_pfnp(pfn_t *pfnp, pfn_t pfn) return VM_FAULT_NEEDDSYNC; } -static vm_fault_t dax_fault_cow_page(struct vm_fault *vmf, struct iomap *iomap, - loff_t pos) +static vm_fault_t dax_fault_cow_page(struct vm_fault *vmf, + const struct iomap_iter *iter) { - sector_t sector = dax_iomap_sector(iomap, pos); + sector_t sector = dax_iomap_sector(&iter->iomap, iter->pos); unsigned long vaddr = vmf->address; vm_fault_t ret; int error = 0; - switch (iomap->type) { + switch (iter->iomap.type) { case IOMAP_HOLE: case IOMAP_UNWRITTEN: clear_user_highpage(vmf->cow_page, vaddr); break; case IOMAP_MAPPED: - error = copy_cow_page_dax(iomap->bdev, iomap->dax_dev, sector, - vmf->cow_page, vaddr); + error = copy_cow_page_dax(iter->iomap.bdev, iter->iomap.dax_dev, + sector, vmf->cow_page, vaddr); break; default: WARN_ON_ONCE(1); @@ -1363,29 +1363,31 @@ static vm_fault_t dax_fault_cow_page(struct vm_fault *vmf, struct iomap *iomap, } /** - * dax_fault_actor - Common actor to handle pfn insertion in PTE/PMD fault. + * dax_fault_iter - Common actor to handle pfn insertion in PTE/PMD fault. * @vmf: vm fault instance + * @iter: iomap iter * @pfnp: pfn to be returned * @xas: the dax mapping tree of a file * @entry: an unlocked dax entry to be inserted * @pmd: distinguish whether it is a pmd fault - * @flags: iomap flags - * @iomap: from iomap_begin() - * @srcmap: from iomap_begin(), not equal to iomap if it is a CoW */ -static vm_fault_t dax_fault_actor(struct vm_fault *vmf, pfn_t *pfnp, - struct xa_state *xas, void **entry, bool pmd, - unsigned int flags, struct iomap *iomap, struct iomap *srcmap) +static vm_fault_t dax_fault_iter(struct vm_fault *vmf, + const struct iomap_iter *iter, pfn_t *pfnp, + struct xa_state *xas, void **entry, bool pmd) { struct address_space *mapping = vmf->vma->vm_file->f_mapping; + const struct iomap *iomap = &iter->iomap; size_t size = pmd ? PMD_SIZE : PAGE_SIZE; loff_t pos = (loff_t)xas->xa_index << PAGE_SHIFT; bool write = vmf->flags & FAULT_FLAG_WRITE; - bool sync = dax_fault_is_synchronous(flags, vmf->vma, iomap); + bool sync = dax_fault_is_synchronous(iter->flags, vmf->vma, iomap); unsigned long entry_flags = pmd ? DAX_PMD : 0; int err = 0; pfn_t pfn; + if (!pmd && vmf->cow_page) + return dax_fault_cow_page(vmf, iter); + /* if we are reading UNWRITTEN and HOLE, return a hole. */ if (!write && (iomap->type == IOMAP_UNWRITTEN || iomap->type == IOMAP_HOLE)) { @@ -1399,7 +1401,7 @@ static vm_fault_t dax_fault_actor(struct vm_fault *vmf, pfn_t *pfnp, return pmd ? VM_FAULT_FALLBACK : VM_FAULT_SIGBUS; } - err = dax_iomap_pfn(iomap, pos, size, &pfn); + err = dax_iomap_pfn(&iter->iomap, pos, size, &pfn); if (err) return pmd ? VM_FAULT_FALLBACK : dax_fault_return(err); @@ -1422,32 +1424,31 @@ static vm_fault_t dax_fault_actor(struct vm_fault *vmf, pfn_t *pfnp, static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, int *iomap_errp, const struct iomap_ops *ops) { - struct vm_area_struct *vma = vmf->vma; - struct address_space *mapping = vma->vm_file->f_mapping; + struct address_space *mapping = vmf->vma->vm_file->f_mapping; XA_STATE(xas, &mapping->i_pages, vmf->pgoff); - struct inode *inode = mapping->host; - loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; - struct iomap iomap = { .type = IOMAP_HOLE }; - struct iomap srcmap = { .type = IOMAP_HOLE }; - unsigned flags = IOMAP_FAULT; - int error; - bool write = vmf->flags & FAULT_FLAG_WRITE; - vm_fault_t ret = 0, major = 0; + struct iomap_iter iter = { + .inode = mapping->host, + .pos = (loff_t)vmf->pgoff << PAGE_SHIFT, + .len = PAGE_SIZE, + .flags = IOMAP_FAULT, + }; + vm_fault_t ret = 0; void *entry; + int error; - trace_dax_pte_fault(inode, vmf, ret); + trace_dax_pte_fault(iter.inode, vmf, ret); /* * Check whether offset isn't beyond end of file now. Caller is supposed * to hold locks serializing us with truncate / punch hole so this is * a reliable test. */ - if (pos >= i_size_read(inode)) { + if (iter.pos >= i_size_read(iter.inode)) { ret = VM_FAULT_SIGBUS; goto out; } - if (write && !vmf->cow_page) - flags |= IOMAP_WRITE; + if ((vmf->flags & FAULT_FLAG_WRITE) && !vmf->cow_page) + iter.flags |= IOMAP_WRITE; entry = grab_mapping_entry(&xas, mapping, 0); if (xa_is_internal(entry)) { @@ -1466,59 +1467,34 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, goto unlock_entry; } - /* - * Note that we don't bother to use iomap_iter here: DAX required - * the file system block size to be equal the page size, which means - * that we never have to deal with more than a single extent here. - */ - error = ops->iomap_begin(inode, pos, PAGE_SIZE, flags, &iomap, &srcmap); - if (iomap_errp) - *iomap_errp = error; - if (error) { - ret = dax_fault_return(error); - goto unlock_entry; - } - if (WARN_ON_ONCE(iomap.offset + iomap.length < pos + PAGE_SIZE)) { - ret = VM_FAULT_SIGBUS; /* fs corruption? */ - goto finish_iomap; - } - - if (vmf->cow_page) { - ret = dax_fault_cow_page(vmf, &iomap, pos); - goto finish_iomap; - } + while ((error = iomap_iter(&iter, ops)) > 0) { + if (WARN_ON_ONCE(iomap_length(&iter) < PAGE_SIZE)) { + iter.processed = -EIO; /* fs corruption? */ + continue; + } - ret = dax_fault_actor(vmf, pfnp, &xas, &entry, false, flags, - &iomap, &srcmap); - if (ret == VM_FAULT_SIGBUS) - goto finish_iomap; + ret = dax_fault_iter(vmf, &iter, pfnp, &xas, &entry, false); + if (ret != VM_FAULT_SIGBUS && + (iter.iomap.flags & IOMAP_F_NEW)) { + count_vm_event(PGMAJFAULT); + count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT); + ret |= VM_FAULT_MAJOR; + } - /* read/write MAPPED, CoW UNWRITTEN */ - if (iomap.flags & IOMAP_F_NEW) { - count_vm_event(PGMAJFAULT); - count_memcg_event_mm(vma->vm_mm, PGMAJFAULT); - major = VM_FAULT_MAJOR; + if (!(ret & VM_FAULT_ERROR)) + iter.processed = PAGE_SIZE; } -finish_iomap: - if (ops->iomap_end) { - int copied = PAGE_SIZE; + if (iomap_errp) + *iomap_errp = error; + if (!ret && error) + ret = dax_fault_return(error); - if (ret & VM_FAULT_ERROR) - copied = 0; - /* - * The fault is done by now and there's no way back (other - * thread may be already happily using PTE we have installed). - * Just ignore error from ->iomap_end since we cannot do much - * with it. - */ - ops->iomap_end(inode, pos, PAGE_SIZE, copied, flags, &iomap); - } unlock_entry: dax_unlock_entry(&xas, entry); out: - trace_dax_pte_fault_done(inode, vmf, ret); - return ret | major; + trace_dax_pte_fault_done(iter.inode, vmf, ret); + return ret; } #ifdef CONFIG_FS_DAX_PMD @@ -1558,28 +1534,29 @@ static bool dax_fault_check_fallback(struct vm_fault *vmf, struct xa_state *xas, static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, const struct iomap_ops *ops) { - struct vm_area_struct *vma = vmf->vma; - struct address_space *mapping = vma->vm_file->f_mapping; + struct address_space *mapping = vmf->vma->vm_file->f_mapping; XA_STATE_ORDER(xas, &mapping->i_pages, vmf->pgoff, PMD_ORDER); - bool write = vmf->flags & FAULT_FLAG_WRITE; - unsigned int flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT; - struct inode *inode = mapping->host; + struct iomap_iter iter = { + .inode = mapping->host, + .len = PMD_SIZE, + .flags = IOMAP_FAULT, + }; vm_fault_t ret = VM_FAULT_FALLBACK; - struct iomap iomap = { .type = IOMAP_HOLE }; - struct iomap srcmap = { .type = IOMAP_HOLE }; pgoff_t max_pgoff; void *entry; - loff_t pos; int error; + if (vmf->flags & FAULT_FLAG_WRITE) + iter.flags |= IOMAP_WRITE; + /* * Check whether offset isn't beyond end of file now. Caller is * supposed to hold locks serializing us with truncate / punch hole so * this is a reliable test. */ - max_pgoff = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); + max_pgoff = DIV_ROUND_UP(i_size_read(iter.inode), PAGE_SIZE); - trace_dax_pmd_fault(inode, vmf, max_pgoff, 0); + trace_dax_pmd_fault(iter.inode, vmf, max_pgoff, 0); if (xas.xa_index >= max_pgoff) { ret = VM_FAULT_SIGBUS; @@ -1613,45 +1590,25 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, goto unlock_entry; } - /* - * Note that we don't use iomap_iter here. We aren't doing I/O, only - * setting up a mapping, so really we're using iomap_begin() as a way - * to look up our filesystem block. - */ - pos = (loff_t)xas.xa_index << PAGE_SHIFT; - error = ops->iomap_begin(inode, pos, PMD_SIZE, flags, &iomap, &srcmap); - if (error) - goto unlock_entry; - - if (iomap.offset + iomap.length < pos + PMD_SIZE) - goto finish_iomap; + iter.pos = (loff_t)xas.xa_index << PAGE_SHIFT; + while ((error = iomap_iter(&iter, ops)) > 0) { + if (iomap_length(&iter) < PMD_SIZE) + continue; /* actually breaks out of the loop */ - ret = dax_fault_actor(vmf, pfnp, &xas, &entry, true, flags, - &iomap, &srcmap); - -finish_iomap: - if (ops->iomap_end) { - int copied = PMD_SIZE; - - if (ret == VM_FAULT_FALLBACK) - copied = 0; - /* - * The fault is done by now and there's no way back (other - * thread may be already happily using PMD we have installed). - * Just ignore error from ->iomap_end since we cannot do much - * with it. - */ - ops->iomap_end(inode, pos, PMD_SIZE, copied, flags, &iomap); + ret = dax_fault_iter(vmf, &iter, pfnp, &xas, &entry, true); + if (ret != VM_FAULT_FALLBACK) + iter.processed = PMD_SIZE; } + unlock_entry: dax_unlock_entry(&xas, entry); fallback: if (ret == VM_FAULT_FALLBACK) { - split_huge_pmd(vma, vmf->pmd, vmf->address); + split_huge_pmd(vmf->vma, vmf->pmd, vmf->address); count_vm_event(THP_FAULT_FALLBACK); } out: - trace_dax_pmd_fault_done(inode, vmf, max_pgoff, ret); + trace_dax_pmd_fault_done(iter.inode, vmf, max_pgoff, ret); return ret; } #else |