[PATCH V10 00/12] Btrfs: Pre subpagesize-blocksize cleanups

[Chandan Rajendra <chandan@linux.vnet.ibm.com>]

The patches posted along with this cover letter are cleanups made
during the development of subpagesize-blocksize patchset. I have
tested the patchset by running fstests on ppc64 and x86_64 machines.

Changes from V9:
1. Dropped the patch "Btrfs: prepare_pages: Retry adding a page to the
   page cache". This issue has already been fixed in the upstream
   kernel.
2. Added a patch to fix a data corruption issue that is observed after
   a clone operation.

Changes from V8:
1. Removed the patch "Btrfs: Return valid delalloc range when the page
   does not have PG_Dirty flag set or has been invalidated". The patch
   was written with the understanding that writepage_delalloc() could
   return delalloc_start which is greater than
   "page_offset(locked_page) + PAGE_CACHE_SIZE - 1". This scenario can
   never occur with the mainline kernel because in
   find_delalloc_range() even if EXTENT_DELALLOC bit isn't set for
   the file range corresponding to the locked page, we would
   definitely have EXTENT_UPTODATE bit set.
   The core subpagesize-blocksize patchset tracks "uptodate" status
   using a per-page bitmap and this caused find_delalloc_range to
   change its default behaviour.

Changes from V7:
1. The second argument passed to btrfs_delalloc_release_space() in
   btrfs_page_mkwrite() was incorrect. Version V8 fixes this.
   
Changes from V6:
1. Rebased on linux-btrfs/integration-4.4 branch. As a result the
   following patches have been trivially modified.
`  - Btrfs: __btrfs_buffered_write: Reserve/release extents aligned
     to block size.
   - Btrfs: fallocate: Work with sectorsized blocks.
   - Btrfs: btrfs_page_mkwrite: Reserve space in sectorsized units.

Changes from V5:
1. Introduced BTRFS_BYTES_TO_BLKS() helper to compute the number of
   filesystem blocks spanning across a range of bytes. A call to this
   macro replaces code such as "nr_blks = bytes >> inode->i_blkbits".

Changes from V4:
1. Removed the RFC tag.

Changes from V3:
Two new issues have been been fixed by the patches,
1. Btrfs: prepare_pages: Retry adding a page to the page cache.
2. Btrfs: Return valid delalloc range when the page does not have
   PG_Dirty flag set or has been invalidated.
IMHO, The above issues are also applicable to the "page size == block
size" scenario but for reasons unknown to me they aren't seen even
when the tests are run for a long time.

Changes from V2:
1. For detecting logical errors, Use ASSERT() calls instead of calls to
   BUG_ON().
2. In the patch "Btrfs: Compute and look up csums based on sectorsized
   blocks", fix usage of kmap_atomic/kunmap_atomic such that between the
   kmap_atomic() and kunmap_atomic() calls we do not invoke any function
   that might cause the current task to sleep.
   
Changes from V1:
1. Call round_[down,up]() functions instead of doing hard coded alignment.

Chandan Rajendra (12):
  Btrfs: __btrfs_buffered_write: Reserve/release extents aligned to
    block size
  Btrfs: Compute and look up csums based on sectorsized blocks
  Btrfs: Direct I/O read: Work on sectorsized blocks
  Btrfs: fallocate: Work with sectorsized blocks
  Btrfs: btrfs_page_mkwrite: Reserve space in sectorsized units
  Btrfs: Search for all ordered extents that could span across a page
  Btrfs: Use (eb->start, seq) as search key for tree modification log
  Btrfs: btrfs_submit_direct_hook: Handle map_length < bio vector length
  Btrfs: Limit inline extents to root->sectorsize
  Btrfs: Fix block size returned to user space
  Btrfs: Clean pte corresponding to page straddling i_size
  Btrfs: btrfs_ioctl_clone: Truncate complete page after performing
    clone operation

 fs/btrfs/ctree.c     |  34 +++----
 fs/btrfs/ctree.h     |   5 +-
 fs/btrfs/extent_io.c |   3 +-
 fs/btrfs/file-item.c |  92 ++++++++++++-------
 fs/btrfs/file.c      |  99 ++++++++++++--------
 fs/btrfs/inode.c     | 248 ++++++++++++++++++++++++++++++++++++---------------
 fs/btrfs/ioctl.c     |   5 +-
 7 files changed, 321 insertions(+), 165 deletions(-)

-- 
2.1.0