From acc93d30d7d43f428272c20a047389c4cbca82ba Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sat, 7 May 2016 11:40:28 -0700 Subject: Revert "block: enable dax for raw block devices" This reverts commit 5a023cdba50c5f5f2bc351783b3131699deb3937. The functionality is superseded by the new "Device DAX" facility. Cc: Jeff Moyer Cc: Christoph Hellwig Cc: Dave Chinner Cc: Andrew Morton Cc: Ross Zwisler Cc: Jan Kara Signed-off-by: Dan Williams --- fs/block_dev.c | 96 ++++++++++++++++++---------------------------------------- 1 file changed, 29 insertions(+), 67 deletions(-) (limited to 'fs') diff --git a/fs/block_dev.c b/fs/block_dev.c index 20a2c02..36ee10c 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include "internal.h" @@ -1159,6 +1160,33 @@ void bd_set_size(struct block_device *bdev, loff_t size) } EXPORT_SYMBOL(bd_set_size); +static bool blkdev_dax_capable(struct block_device *bdev) +{ + struct gendisk *disk = bdev->bd_disk; + + if (!disk->fops->direct_access || !IS_ENABLED(CONFIG_FS_DAX)) + return false; + + /* + * If the partition is not aligned on a page boundary, we can't + * do dax I/O to it. + */ + if ((bdev->bd_part->start_sect % (PAGE_SIZE / 512)) + || (bdev->bd_part->nr_sects % (PAGE_SIZE / 512))) + return false; + + /* + * If the device has known bad blocks, force all I/O through the + * driver / page cache. + * + * TODO: support finer grained dax error handling + */ + if (disk->bb && disk->bb->count) + return false; + + return true; +} + static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); /* @@ -1724,79 +1752,13 @@ static const struct address_space_operations def_blk_aops = { .is_dirty_writeback = buffer_check_dirty_writeback, }; -#ifdef CONFIG_FS_DAX -/* - * In the raw block case we do not need to contend with truncation nor - * unwritten file extents. Without those concerns there is no need for - * additional locking beyond the mmap_sem context that these routines - * are already executing under. - * - * Note, there is no protection if the block device is dynamically - * resized (partition grow/shrink) during a fault. A stable block device - * size is already not enforced in the blkdev_direct_IO path. - * - * For DAX, it is the responsibility of the block device driver to - * ensure the whole-disk device size is stable while requests are in - * flight. - * - * Finally, unlike the filemap_page_mkwrite() case there is no - * filesystem superblock to sync against freezing. We still include a - * pfn_mkwrite callback for dax drivers to receive write fault - * notifications. - */ -static int blkdev_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) -{ - return __dax_fault(vma, vmf, blkdev_get_block, NULL); -} - -static int blkdev_dax_pfn_mkwrite(struct vm_area_struct *vma, - struct vm_fault *vmf) -{ - return dax_pfn_mkwrite(vma, vmf); -} - -static int blkdev_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr, - pmd_t *pmd, unsigned int flags) -{ - return __dax_pmd_fault(vma, addr, pmd, flags, blkdev_get_block, NULL); -} - -static const struct vm_operations_struct blkdev_dax_vm_ops = { - .fault = blkdev_dax_fault, - .pmd_fault = blkdev_dax_pmd_fault, - .pfn_mkwrite = blkdev_dax_pfn_mkwrite, -}; - -static const struct vm_operations_struct blkdev_default_vm_ops = { - .fault = filemap_fault, - .map_pages = filemap_map_pages, -}; - -static int blkdev_mmap(struct file *file, struct vm_area_struct *vma) -{ - struct inode *bd_inode = bdev_file_inode(file); - - file_accessed(file); - if (IS_DAX(bd_inode)) { - vma->vm_ops = &blkdev_dax_vm_ops; - vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE; - } else { - vma->vm_ops = &blkdev_default_vm_ops; - } - - return 0; -} -#else -#define blkdev_mmap generic_file_mmap -#endif - const struct file_operations def_blk_fops = { .open = blkdev_open, .release = blkdev_close, .llseek = block_llseek, .read_iter = blkdev_read_iter, .write_iter = blkdev_write_iter, - .mmap = blkdev_mmap, + .mmap = generic_file_mmap, .fsync = blkdev_fsync, .unlocked_ioctl = block_ioctl, #ifdef CONFIG_COMPAT -- cgit v1.1