From cccbce67158290537cc671cbd4c1564876485a65 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 27 Jan 2017 13:31:42 -0800 Subject: [PATCH] filesystem-dax: convert to dax_direct_access() Now that a dax_device is plumbed through all dax-capable drivers we can switch from block_device_operations to dax_operations for invoking ->direct_access. This also lets us kill off some usages of struct blk_dax_ctl on the way to its eventual removal. Suggested-by: Christoph Hellwig Signed-off-by: Dan Williams --- fs/dax.c | 277 +++++++++++++++++++++++++------------------- fs/iomap.c | 3 +- include/linux/dax.h | 6 +- 3 files changed, 162 insertions(+), 124 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index b78a6947c4f5..ce9dc9c3e829 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -55,32 +55,6 @@ static int __init init_dax_wait_table(void) } fs_initcall(init_dax_wait_table); -static long dax_map_atomic(struct block_device *bdev, struct blk_dax_ctl *dax) -{ - struct request_queue *q = bdev->bd_queue; - long rc = -EIO; - - dax->addr = ERR_PTR(-EIO); - if (blk_queue_enter(q, true) != 0) - return rc; - - rc = bdev_direct_access(bdev, dax); - if (rc < 0) { - dax->addr = ERR_PTR(rc); - blk_queue_exit(q); - return rc; - } - return rc; -} - -static void dax_unmap_atomic(struct block_device *bdev, - const struct blk_dax_ctl *dax) -{ - if (IS_ERR(dax->addr)) - return; - blk_queue_exit(bdev->bd_queue); -} - static int dax_is_pmd_entry(void *entry) { return (unsigned long)entry & RADIX_DAX_PMD; @@ -553,21 +527,30 @@ static int dax_load_hole(struct address_space *mapping, void **entry, return ret; } -static int copy_user_dax(struct block_device *bdev, sector_t sector, size_t size, - struct page *to, unsigned long vaddr) +static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev, + sector_t sector, size_t size, struct page *to, + unsigned long vaddr) { - struct blk_dax_ctl dax = { - .sector = sector, - .size = size, - }; - void *vto; - - if (dax_map_atomic(bdev, &dax) < 0) - return PTR_ERR(dax.addr); + void *vto, *kaddr; + pgoff_t pgoff; + pfn_t pfn; + long rc; + int id; + + rc = bdev_dax_pgoff(bdev, sector, size, &pgoff); + if (rc) + return rc; + + id = dax_read_lock(); + rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn); + if (rc < 0) { + dax_read_unlock(id); + return rc; + } vto = kmap_atomic(to); - copy_user_page(vto, (void __force *)dax.addr, vaddr, to); + copy_user_page(vto, (void __force *)kaddr, vaddr, to); kunmap_atomic(vto); - dax_unmap_atomic(bdev, &dax); + dax_read_unlock(id); return 0; } @@ -735,12 +718,16 @@ unlock_pte: } static int dax_writeback_one(struct block_device *bdev, - struct address_space *mapping, pgoff_t index, void *entry) + struct dax_device *dax_dev, struct address_space *mapping, + pgoff_t index, void *entry) { struct radix_tree_root *page_tree = &mapping->page_tree; - struct blk_dax_ctl dax; - void *entry2, **slot; - int ret = 0; + void *entry2, **slot, *kaddr; + long ret = 0, id; + sector_t sector; + pgoff_t pgoff; + size_t size; + pfn_t pfn; /* * A page got tagged dirty in DAX mapping? Something is seriously @@ -789,26 +776,29 @@ static int dax_writeback_one(struct block_device *bdev, * 'entry'. This allows us to flush for PMD_SIZE and not have to * worry about partial PMD writebacks. */ - dax.sector = dax_radix_sector(entry); - dax.size = PAGE_SIZE << dax_radix_order(entry); + sector = dax_radix_sector(entry); + size = PAGE_SIZE << dax_radix_order(entry); + + id = dax_read_lock(); + ret = bdev_dax_pgoff(bdev, sector, size, &pgoff); + if (ret) + goto dax_unlock; /* - * We cannot hold tree_lock while calling dax_map_atomic() because it - * eventually calls cond_resched(). + * dax_direct_access() may sleep, so cannot hold tree_lock over + * its invocation. */ - ret = dax_map_atomic(bdev, &dax); - if (ret < 0) { - put_locked_mapping_entry(mapping, index, entry); - return ret; - } + ret = dax_direct_access(dax_dev, pgoff, size / PAGE_SIZE, &kaddr, &pfn); + if (ret < 0) + goto dax_unlock; - if (WARN_ON_ONCE(ret < dax.size)) { + if (WARN_ON_ONCE(ret < size / PAGE_SIZE)) { ret = -EIO; - goto unmap; + goto dax_unlock; } - dax_mapping_entry_mkclean(mapping, index, pfn_t_to_pfn(dax.pfn)); - wb_cache_pmem(dax.addr, dax.size); + dax_mapping_entry_mkclean(mapping, index, pfn_t_to_pfn(pfn)); + wb_cache_pmem(kaddr, size); /* * After we have flushed the cache, we can clear the dirty tag. There * cannot be new dirty data in the pfn after the flush has completed as @@ -818,8 +808,8 @@ static int dax_writeback_one(struct block_device *bdev, spin_lock_irq(&mapping->tree_lock); radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_DIRTY); spin_unlock_irq(&mapping->tree_lock); - unmap: - dax_unmap_atomic(bdev, &dax); + dax_unlock: + dax_read_unlock(id); put_locked_mapping_entry(mapping, index, entry); return ret; @@ -840,6 +830,7 @@ int dax_writeback_mapping_range(struct address_space *mapping, struct inode *inode = mapping->host; pgoff_t start_index, end_index; pgoff_t indices[PAGEVEC_SIZE]; + struct dax_device *dax_dev; struct pagevec pvec; bool done = false; int i, ret = 0; @@ -850,6 +841,10 @@ int dax_writeback_mapping_range(struct address_space *mapping, if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL) return 0; + dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); + if (!dax_dev) + return -EIO; + start_index = wbc->range_start >> PAGE_SHIFT; end_index = wbc->range_end >> PAGE_SHIFT; @@ -870,38 +865,49 @@ int dax_writeback_mapping_range(struct address_space *mapping, break; } - ret = dax_writeback_one(bdev, mapping, indices[i], - pvec.pages[i]); - if (ret < 0) + ret = dax_writeback_one(bdev, dax_dev, mapping, + indices[i], pvec.pages[i]); + if (ret < 0) { + put_dax(dax_dev); return ret; + } } } + put_dax(dax_dev); return 0; } EXPORT_SYMBOL_GPL(dax_writeback_mapping_range); static int dax_insert_mapping(struct address_space *mapping, - struct block_device *bdev, sector_t sector, size_t size, - void **entryp, struct vm_area_struct *vma, struct vm_fault *vmf) + struct block_device *bdev, struct dax_device *dax_dev, + sector_t sector, size_t size, void **entryp, + struct vm_area_struct *vma, struct vm_fault *vmf) { unsigned long vaddr = vmf->address; - struct blk_dax_ctl dax = { - .sector = sector, - .size = size, - }; - void *ret; void *entry = *entryp; + void *ret, *kaddr; + pgoff_t pgoff; + int id, rc; + pfn_t pfn; - if (dax_map_atomic(bdev, &dax) < 0) - return PTR_ERR(dax.addr); - dax_unmap_atomic(bdev, &dax); + rc = bdev_dax_pgoff(bdev, sector, size, &pgoff); + if (rc) + return rc; - ret = dax_insert_mapping_entry(mapping, vmf, entry, dax.sector, 0); + id = dax_read_lock(); + rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn); + if (rc < 0) { + dax_read_unlock(id); + return rc; + } + dax_read_unlock(id); + + ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0); if (IS_ERR(ret)) return PTR_ERR(ret); *entryp = ret; - return vm_insert_mixed(vma, vaddr, dax.pfn); + return vm_insert_mixed(vma, vaddr, pfn); } /** @@ -950,24 +956,34 @@ static bool dax_range_is_aligned(struct block_device *bdev, return true; } -int __dax_zero_page_range(struct block_device *bdev, sector_t sector, - unsigned int offset, unsigned int length) +int __dax_zero_page_range(struct block_device *bdev, + struct dax_device *dax_dev, sector_t sector, + unsigned int offset, unsigned int size) { - struct blk_dax_ctl dax = { - .sector = sector, - .size = PAGE_SIZE, - }; - - if (dax_range_is_aligned(bdev, offset, length)) { - sector_t start_sector = dax.sector + (offset >> 9); + if (dax_range_is_aligned(bdev, offset, size)) { + sector_t start_sector = sector + (offset >> 9); return blkdev_issue_zeroout(bdev, start_sector, - length >> 9, GFP_NOFS, true); + size >> 9, GFP_NOFS, true); } else { - if (dax_map_atomic(bdev, &dax) < 0) - return PTR_ERR(dax.addr); - clear_pmem(dax.addr + offset, length); - dax_unmap_atomic(bdev, &dax); + pgoff_t pgoff; + long rc, id; + void *kaddr; + pfn_t pfn; + + rc = bdev_dax_pgoff(bdev, sector, size, &pgoff); + if (rc) + return rc; + + id = dax_read_lock(); + rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, + &pfn); + if (rc < 0) { + dax_read_unlock(id); + return rc; + } + clear_pmem(kaddr + offset, size); + dax_read_unlock(id); } return 0; } @@ -982,9 +998,12 @@ static loff_t dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, struct iomap *iomap) { + struct block_device *bdev = iomap->bdev; + struct dax_device *dax_dev = iomap->dax_dev; struct iov_iter *iter = data; loff_t end = pos + length, done = 0; ssize_t ret = 0; + int id; if (iov_iter_rw(iter) == READ) { end = min(end, i_size_read(inode)); @@ -1009,34 +1028,42 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, (end - 1) >> PAGE_SHIFT); } + id = dax_read_lock(); while (pos < end) { unsigned offset = pos & (PAGE_SIZE - 1); - struct blk_dax_ctl dax = { 0 }; + const size_t size = ALIGN(length + offset, PAGE_SIZE); + const sector_t sector = dax_iomap_sector(iomap, pos); ssize_t map_len; + pgoff_t pgoff; + void *kaddr; + pfn_t pfn; if (fatal_signal_pending(current)) { ret = -EINTR; break; } - dax.sector = dax_iomap_sector(iomap, pos); - dax.size = (length + offset + PAGE_SIZE - 1) & PAGE_MASK; - map_len = dax_map_atomic(iomap->bdev, &dax); + ret = bdev_dax_pgoff(bdev, sector, size, &pgoff); + if (ret) + break; + + map_len = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), + &kaddr, &pfn); if (map_len < 0) { ret = map_len; break; } - dax.addr += offset; + map_len = PFN_PHYS(map_len); + kaddr += offset; map_len -= offset; if (map_len > end - pos) map_len = end - pos; if (iov_iter_rw(iter) == WRITE) - map_len = copy_from_iter_pmem(dax.addr, map_len, iter); + map_len = copy_from_iter_pmem(kaddr, map_len, iter); else - map_len = copy_to_iter(dax.addr, map_len, iter); - dax_unmap_atomic(iomap->bdev, &dax); + map_len = copy_to_iter(kaddr, map_len, iter); if (map_len <= 0) { ret = map_len ? map_len : -EFAULT; break; @@ -1046,6 +1073,7 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, length -= map_len; done += map_len; } + dax_read_unlock(id); return done ? done : ret; } @@ -1152,8 +1180,8 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, clear_user_highpage(vmf->cow_page, vaddr); break; case IOMAP_MAPPED: - error = copy_user_dax(iomap.bdev, sector, PAGE_SIZE, - vmf->cow_page, vaddr); + error = copy_user_dax(iomap.bdev, iomap.dax_dev, + sector, PAGE_SIZE, vmf->cow_page, vaddr); break; default: WARN_ON_ONCE(1); @@ -1178,8 +1206,8 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, mem_cgroup_count_vm_event(vmf->vma->vm_mm, PGMAJFAULT); major = VM_FAULT_MAJOR; } - error = dax_insert_mapping(mapping, iomap.bdev, sector, - PAGE_SIZE, &entry, vmf->vma, vmf); + error = dax_insert_mapping(mapping, iomap.bdev, iomap.dax_dev, + sector, PAGE_SIZE, &entry, vmf->vma, vmf); /* -EBUSY is fine, somebody else faulted on the same PTE */ if (error == -EBUSY) error = 0; @@ -1229,41 +1257,48 @@ static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap, loff_t pos, void **entryp) { struct address_space *mapping = vmf->vma->vm_file->f_mapping; + const sector_t sector = dax_iomap_sector(iomap, pos); + struct dax_device *dax_dev = iomap->dax_dev; struct block_device *bdev = iomap->bdev; struct inode *inode = mapping->host; - struct blk_dax_ctl dax = { - .sector = dax_iomap_sector(iomap, pos), - .size = PMD_SIZE, - }; - long length = dax_map_atomic(bdev, &dax); - void *ret = NULL; - - if (length < 0) /* dax_map_atomic() failed */ + const size_t size = PMD_SIZE; + void *ret = NULL, *kaddr; + long length = 0; + pgoff_t pgoff; + pfn_t pfn; + int id; + + if (bdev_dax_pgoff(bdev, sector, size, &pgoff) != 0) goto fallback; - if (length < PMD_SIZE) - goto unmap_fallback; - if (pfn_t_to_pfn(dax.pfn) & PG_PMD_COLOUR) - goto unmap_fallback; - if (!pfn_t_devmap(dax.pfn)) - goto unmap_fallback; - - dax_unmap_atomic(bdev, &dax); - ret = dax_insert_mapping_entry(mapping, vmf, *entryp, dax.sector, + id = dax_read_lock(); + length = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn); + if (length < 0) + goto unlock_fallback; + length = PFN_PHYS(length); + + if (length < size) + goto unlock_fallback; + if (pfn_t_to_pfn(pfn) & PG_PMD_COLOUR) + goto unlock_fallback; + if (!pfn_t_devmap(pfn)) + goto unlock_fallback; + dax_read_unlock(id); + + ret = dax_insert_mapping_entry(mapping, vmf, *entryp, sector, RADIX_DAX_PMD); if (IS_ERR(ret)) goto fallback; *entryp = ret; - trace_dax_pmd_insert_mapping(inode, vmf, length, dax.pfn, ret); + trace_dax_pmd_insert_mapping(inode, vmf, length, pfn, ret); return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, - dax.pfn, vmf->flags & FAULT_FLAG_WRITE); + pfn, vmf->flags & FAULT_FLAG_WRITE); - unmap_fallback: - dax_unmap_atomic(bdev, &dax); +unlock_fallback: + dax_read_unlock(id); fallback: - trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, - dax.pfn, ret); + trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, pfn, ret); return VM_FAULT_FALLBACK; } diff --git a/fs/iomap.c b/fs/iomap.c index 141c3cd55a8b..4ec0d6ac8bc1 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -360,7 +360,8 @@ static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes, sector_t sector = iomap->blkno + (((pos & ~(PAGE_SIZE - 1)) - iomap->offset) >> 9); - return __dax_zero_page_range(iomap->bdev, sector, offset, bytes); + return __dax_zero_page_range(iomap->bdev, iomap->dax_dev, sector, + offset, bytes); } static loff_t diff --git a/include/linux/dax.h b/include/linux/dax.h index 0d0d890f9186..d3158e74a59e 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -70,11 +70,13 @@ void dax_wake_mapping_entry_waiter(struct address_space *mapping, pgoff_t index, void *entry, bool wake_all); #ifdef CONFIG_FS_DAX -int __dax_zero_page_range(struct block_device *bdev, sector_t sector, +int __dax_zero_page_range(struct block_device *bdev, + struct dax_device *dax_dev, sector_t sector, unsigned int offset, unsigned int length); #else static inline int __dax_zero_page_range(struct block_device *bdev, - sector_t sector, unsigned int offset, unsigned int length) + struct dax_device *dax_dev, sector_t sector, + unsigned int offset, unsigned int length) { return -ENXIO; } -- 2.20.1