diff options
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) |
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) | |||
151 | struct file *file = iocb->ki_filp; | 151 | struct file *file = iocb->ki_filp; |
152 | struct inode *inode = file->f_mapping->host; | 152 | struct inode *inode = file->f_mapping->host; |
153 | 153 | ||
154 | if (IS_DAX(inode)) | ||
155 | return dax_do_io(iocb, inode, iter, offset, blkdev_get_block, | ||
156 | NULL, DIO_SKIP_DIO_COUNT); | ||
154 | return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter, offset, | 157 | return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter, offset, |
155 | blkdev_get_block, NULL, NULL, | 158 | blkdev_get_block, NULL, NULL, |
156 | DIO_SKIP_DIO_COUNT); | 159 | DIO_SKIP_DIO_COUNT); |
@@ -1173,6 +1176,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) | |||
1173 | bdev->bd_disk = disk; | 1176 | bdev->bd_disk = disk; |
1174 | bdev->bd_queue = disk->queue; | 1177 | bdev->bd_queue = disk->queue; |
1175 | bdev->bd_contains = bdev; | 1178 | bdev->bd_contains = bdev; |
1179 | bdev->bd_inode->i_flags = disk->fops->direct_access ? S_DAX : 0; | ||
1176 | if (!partno) { | 1180 | if (!partno) { |
1177 | ret = -ENXIO; | 1181 | ret = -ENXIO; |
1178 | bdev->bd_part = disk_get_part(disk, partno); | 1182 | bdev->bd_part = disk_get_part(disk, partno); |
@@ -209,7 +209,8 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, | |||
209 | } | 209 | } |
210 | 210 | ||
211 | /* Protects against truncate */ | 211 | /* Protects against truncate */ |
212 | inode_dio_begin(inode); | 212 | if (!(flags & DIO_SKIP_DIO_COUNT)) |
213 | inode_dio_begin(inode); | ||
213 | 214 | ||
214 | retval = dax_io(inode, iter, pos, end, get_block, &bh); | 215 | retval = dax_io(inode, iter, pos, end, get_block, &bh); |
215 | 216 | ||
@@ -219,7 +220,8 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, | |||
219 | if ((retval > 0) && end_io) | 220 | if ((retval > 0) && end_io) |
220 | end_io(iocb, pos, retval, bh.b_private); | 221 | end_io(iocb, pos, retval, bh.b_private); |
221 | 222 | ||
222 | inode_dio_end(inode); | 223 | if (!(flags & DIO_SKIP_DIO_COUNT)) |
224 | inode_dio_end(inode); | ||
223 | out: | 225 | out: |
224 | return retval; | 226 | return retval; |
225 | } | 227 | } |