Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 4fe10f93db8a..198243717da5 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -152,6 +152,9 @@ 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);
@@ -443,6 +446,12 @@ long bdev_direct_access(struct block_device *bdev, sector_t sector,
         long avail;
         const struct block_device_operations *ops = bdev->bd_disk->fops;
 
+        /*
+         * The device driver is allowed to sleep, in order to make the
+         * memory directly accessible.
+         */
+        might_sleep();
+
         if (size < 0)
                 return size;
         if (!ops->direct_access)
@@ -1170,6 +1179,7 @@ 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);