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| author | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2015-07-03 10:40:42 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2015-07-04 15:56:57 -0400 |
| commit | bbab37ddc20bae4709bca8745c128c4f46fe63c5 (patch) | |
| tree | 8f0d8b16e1904ef668feb9b9df4f4041db557a20 | |
| parent | 872eb127e3a6cddcfca1410bb808d9b9bc773dc1 (diff) | |
| download | lwn-bbab37ddc20bae4709bca8745c128c4f46fe63c5.tar.gz lwn-bbab37ddc20bae4709bca8745c128c4f46fe63c5.zip | |
block: Add support for DAX reads/writes to block devices
If a block device supports the ->direct_access methods, bypass the normal
DIO path and use DAX to go straight to memcpy() instead of allocating
a DIO and a BIO.
Includes support for the DIO_SKIP_DIO_COUNT flag in DAX, as is done in
do_blockdev_direct_IO().
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/block_dev.c | 4 | ||||
| -rw-r--r-- | fs/dax.c | 6 |
2 files changed, 8 insertions, 2 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index c7e4163ede87..5dde6dff4940 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -151,6 +151,9 @@ blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset) struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; + if (IS_DAX(inode)) + return dax_do_io(iocb, inode, iter, offset, blkdev_get_block, + NULL, DIO_SKIP_DIO_COUNT); return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter, offset, blkdev_get_block, NULL, NULL, DIO_SKIP_DIO_COUNT); @@ -1173,6 +1176,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) bdev->bd_disk = disk; bdev->bd_queue = disk->queue; bdev->bd_contains = bdev; + bdev->bd_inode->i_flags = disk->fops->direct_access ? S_DAX : 0; if (!partno) { ret = -ENXIO; bdev->bd_part = disk_get_part(disk, partno); @@ -209,7 +209,8 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, } /* Protects against truncate */ - inode_dio_begin(inode); + if (!(flags & DIO_SKIP_DIO_COUNT)) + inode_dio_begin(inode); retval = dax_io(inode, iter, pos, end, get_block, &bh); @@ -219,7 +220,8 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, if ((retval > 0) && end_io) end_io(iocb, pos, retval, bh.b_private); - inode_dio_end(inode); + if (!(flags & DIO_SKIP_DIO_COUNT)) + inode_dio_end(inode); out: return retval; } |