diff options
Diffstat (limited to 'fs/block_dev.c')
| -rw-r--r-- | fs/block_dev.c | 77 |
1 files changed, 50 insertions, 27 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index b48c41bf0f86..975266be67d3 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -49,23 +49,15 @@ inline struct block_device *I_BDEV(struct inode *inode) } EXPORT_SYMBOL(I_BDEV); -/* - * Move the inode from its current bdi to a new bdi. Make sure the inode - * is clean before moving so that it doesn't linger on the old bdi. - */ -static void bdev_inode_switch_bdi(struct inode *inode, - struct backing_dev_info *dst) +static void bdev_write_inode(struct inode *inode) { - while (true) { - spin_lock(&inode->i_lock); - if (!(inode->i_state & I_DIRTY)) { - inode->i_data.backing_dev_info = dst; - spin_unlock(&inode->i_lock); - return; - } + spin_lock(&inode->i_lock); + while (inode->i_state & I_DIRTY) { spin_unlock(&inode->i_lock); WARN_ON_ONCE(write_inode_now(inode, true)); + spin_lock(&inode->i_lock); } + spin_unlock(&inode->i_lock); } /* Kill _all_ buffers and pagecache , dirty or not.. */ @@ -429,6 +421,46 @@ int bdev_write_page(struct block_device *bdev, sector_t sector, } EXPORT_SYMBOL_GPL(bdev_write_page); +/** + * bdev_direct_access() - Get the address for directly-accessibly memory + * @bdev: The device containing the memory + * @sector: The offset within the device + * @addr: Where to put the address of the memory + * @pfn: The Page Frame Number for the memory + * @size: The number of bytes requested + * + * If a block device is made up of directly addressable memory, this function + * will tell the caller the PFN and the address of the memory. The address + * may be directly dereferenced within the kernel without the need to call + * ioremap(), kmap() or similar. The PFN is suitable for inserting into + * page tables. + * + * Return: negative errno if an error occurs, otherwise the number of bytes + * accessible at this address. + */ +long bdev_direct_access(struct block_device *bdev, sector_t sector, + void **addr, unsigned long *pfn, long size) +{ + long avail; + const struct block_device_operations *ops = bdev->bd_disk->fops; + + if (size < 0) + return size; + if (!ops->direct_access) + return -EOPNOTSUPP; + if ((sector + DIV_ROUND_UP(size, 512)) > + part_nr_sects_read(bdev->bd_part)) + return -ERANGE; + sector += get_start_sect(bdev); + if (sector % (PAGE_SIZE / 512)) + return -EINVAL; + avail = ops->direct_access(bdev, sector, addr, pfn, size); + if (!avail) + return -ERANGE; + return min(avail, size); +} +EXPORT_SYMBOL_GPL(bdev_direct_access); + /* * pseudo-fs */ @@ -584,7 +616,6 @@ struct block_device *bdget(dev_t dev) inode->i_bdev = bdev; inode->i_data.a_ops = &def_blk_aops; mapping_set_gfp_mask(&inode->i_data, GFP_USER); - inode->i_data.backing_dev_info = &default_backing_dev_info; spin_lock(&bdev_lock); list_add(&bdev->bd_list, &all_bdevs); spin_unlock(&bdev_lock); @@ -1145,8 +1176,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) bdev->bd_queue = disk->queue; bdev->bd_contains = bdev; if (!partno) { - struct backing_dev_info *bdi; - ret = -ENXIO; bdev->bd_part = disk_get_part(disk, partno); if (!bdev->bd_part) @@ -1172,11 +1201,8 @@ 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); - bdi = blk_get_backing_dev_info(bdev); - bdev_inode_switch_bdi(bdev->bd_inode, bdi); - } /* * If the device is invalidated, rescan partition @@ -1203,8 +1229,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) if (ret) goto out_clear; bdev->bd_contains = whole; - bdev_inode_switch_bdi(bdev->bd_inode, - whole->bd_inode->i_data.backing_dev_info); bdev->bd_part = disk_get_part(disk, partno); if (!(disk->flags & GENHD_FL_UP) || !bdev->bd_part || !bdev->bd_part->nr_sects) { @@ -1244,7 +1268,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) bdev->bd_disk = NULL; bdev->bd_part = NULL; bdev->bd_queue = NULL; - bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info); if (bdev != bdev->bd_contains) __blkdev_put(bdev->bd_contains, mode, 1); bdev->bd_contains = NULL; @@ -1464,11 +1487,11 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) WARN_ON_ONCE(bdev->bd_holders); sync_blockdev(bdev); kill_bdev(bdev); - /* ->release can cause the old bdi to disappear, - * so must switch it out first + /* + * ->release can cause the queue to disappear, so flush all + * dirty data before. */ - bdev_inode_switch_bdi(bdev->bd_inode, - &default_backing_dev_info); + bdev_write_inode(bdev->bd_inode); } if (bdev->bd_contains == bdev) { if (disk->fops->release) |