[PATCH 0/2] fs: cache dax_device lookup result

[Dan Williams]

Christoph notes:

    I just noticed that we now do a fs_dax_get_by_host in every
    iomap_begin call for DAX.  This function iterates a list, does a
    string compared and igrab.  I really think we need to cache this in
    the superblock (possible even the fs superblock) similar to what we
    do for the block device.

Fix this up to cache the result of the dax_device lookup in 'struct
xfs_mount' for xfs and 'struct super_block' for ext2/ext4.

---

Dan Williams (2):
      xfs: cache dax_device lookup result
      ext2, ext4: cache dax_device lookup result


 fs/ext2/inode.c    |   11 +++++++----
 fs/ext4/inode.c    |   11 +++++++----
 fs/xfs/xfs_aops.c  |   24 ++++++++++++++++++++++++
 fs/xfs/xfs_aops.h  |    1 +
 fs/xfs/xfs_buf.h   |    1 +
 fs/xfs/xfs_iomap.c |    9 +--------
 include/linux/fs.h |    3 +++
 7 files changed, 44 insertions(+), 16 deletions(-)