Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

[mirror_ubuntu-artful-kernel.git] / block / ioctl.c

diff --git a/block/ioctl.c b/block/ioctl.c
index 0918aed2d847e2ccd1d696ba8260be9592959063..2c84683aada56e4b52c9080b88ce99eb1d7b68c8 100644 (file)
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -4,6 +4,7 @@
 #include <linux/gfp.h>
 #include <linux/blkpg.h>
 #include <linux/hdreg.h>
+#include <linux/badblocks.h>
 #include <linux/backing-dev.h>
 #include <linux/fs.h>
 #include <linux/blktrace_api.h>
@@ -406,6 +407,71 @@ static inline int is_unrecognized_ioctl(int ret)
                ret == -ENOIOCTLCMD;
 }
 
+#ifdef CONFIG_FS_DAX
+bool blkdev_dax_capable(struct block_device *bdev)
+{
+       struct gendisk *disk = bdev->bd_disk;
+
+       if (!disk->fops->direct_access)
+               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 int blkdev_daxset(struct block_device *bdev, unsigned long argp)
+{
+       unsigned long arg;
+       int rc = 0;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EACCES;
+
+       if (get_user(arg, (int __user *)(argp)))
+               return -EFAULT;
+       arg = !!arg;
+       if (arg == !!(bdev->bd_inode->i_flags & S_DAX))
+               return 0;
+
+       if (arg)
+               arg = S_DAX;
+
+       if (arg && !blkdev_dax_capable(bdev))
+               return -ENOTTY;
+
+       mutex_lock(&bdev->bd_inode->i_mutex);
+       if (bdev->bd_map_count == 0)
+               inode_set_flags(bdev->bd_inode, arg, S_DAX);
+       else
+               rc = -EBUSY;
+       mutex_unlock(&bdev->bd_inode->i_mutex);
+       return rc;
+}
+#else
+static int blkdev_daxset(struct block_device *bdev, int arg)
+{
+       if (arg)
+               return -ENOTTY;
+       return 0;
+}
+#endif
+
 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
                unsigned cmd, unsigned long arg)
 {
@@ -568,6 +634,11 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
        case BLKTRACESETUP:
        case BLKTRACETEARDOWN:
                return blk_trace_ioctl(bdev, cmd, argp);
+       case BLKDAXSET:
+               return blkdev_daxset(bdev, arg);
+       case BLKDAXGET:
+               return put_int(arg, !!(bdev->bd_inode->i_flags & S_DAX));
+               break;
        case IOC_PR_REGISTER:
                return blkdev_pr_register(bdev, argp);
        case IOC_PR_RESERVE: