diff options
Diffstat (limited to 'fs/block_dev.c')
| -rw-r--r-- | fs/block_dev.c | 103 |
1 files changed, 95 insertions, 8 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 52248bce42d2..5c0b2cba870e 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1235,8 +1235,11 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) } } - if (!ret) + if (!ret) { bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); + if (!blkdev_dax_capable(bdev)) + bdev->bd_inode->i_flags &= ~S_DAX; + } /* * If the device is invalidated, rescan partition @@ -1250,6 +1253,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) else if (ret == -ENOMEDIUM) invalidate_partitions(disk, bdev); } + if (ret) goto out_clear; } else { @@ -1270,12 +1274,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) goto out_clear; } bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); - /* - * 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))) + if (!blkdev_dax_capable(bdev)) bdev->bd_inode->i_flags &= ~S_DAX; } } else { @@ -1713,13 +1712,101 @@ 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_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 void blkdev_vm_open(struct vm_area_struct *vma) +{ + struct inode *bd_inode = bdev_file_inode(vma->vm_file); + struct block_device *bdev = I_BDEV(bd_inode); + + mutex_lock(&bd_inode->i_mutex); + bdev->bd_map_count++; + mutex_unlock(&bd_inode->i_mutex); +} + +static void blkdev_vm_close(struct vm_area_struct *vma) +{ + struct inode *bd_inode = bdev_file_inode(vma->vm_file); + struct block_device *bdev = I_BDEV(bd_inode); + + mutex_lock(&bd_inode->i_mutex); + bdev->bd_map_count--; + mutex_unlock(&bd_inode->i_mutex); +} + +static const struct vm_operations_struct blkdev_dax_vm_ops = { + .open = blkdev_vm_open, + .close = blkdev_vm_close, + .fault = blkdev_dax_fault, + .pmd_fault = blkdev_dax_pmd_fault, + .pfn_mkwrite = blkdev_dax_fault, +}; + +static const struct vm_operations_struct blkdev_default_vm_ops = { + .open = blkdev_vm_open, + .close = blkdev_vm_close, + .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); + struct block_device *bdev = I_BDEV(bd_inode); + + file_accessed(file); + mutex_lock(&bd_inode->i_mutex); + bdev->bd_map_count++; + 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; + } + mutex_unlock(&bd_inode->i_mutex); + + 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 = generic_file_mmap, + .mmap = blkdev_mmap, .fsync = blkdev_fsync, .unlocked_ioctl = block_ioctl, #ifdef CONFIG_COMPAT |