Merge tag 'for-5.3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "Highlights:

   - chunks that have been trimmed and unchanged since last mount are
     tracked and skipped on repeated trims

   - use hw assissed crc32c on more arches, speedups if native
     instructions or optimized implementation is available

   - the RAID56 incompat bit is automatically removed when the last
     block group of that type is removed

  Fixes:

   - fsync fix for reflink on NODATACOW files that could lead to ENOSPC

   - fix data loss after inode eviction, renaming it, and fsync it

   - fix fsync not persisting dentry deletions due to inode evictions

   - update ctime/mtime/iversion after hole punching

   - fix compression type validation (reported by KASAN)

   - send won't be allowed to start when relocation is in progress, this
     can cause spurious errors or produce incorrect send stream

  Core:

   - new tracepoints for space update

   - tree-checker: better check for end of extents for some tree items

   - preparatory work for more checksum algorithms

   - run delayed iput at unlink time and don't push the work to cleaner
     thread where it's not properly throttled

   - wrap block mapping to structures and helpers, base for further
     refactoring

   - split large files, part 1:
       - space info handling
       - block group reservations
       - delayed refs
       - delayed allocation

   - other cleanups and refactoring"

* tag 'for-5.3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (103 commits)
  btrfs: fix memory leak of path on error return path
  btrfs: move the subvolume reservation stuff out of extent-tree.c
  btrfs: migrate the delalloc space stuff to it's own home
  btrfs: migrate btrfs_trans_release_chunk_metadata
  btrfs: migrate the delayed refs rsv code
  btrfs: Evaluate io_tree in find_lock_delalloc_range()
  btrfs: migrate the global_block_rsv helpers to block-rsv.c
  btrfs: migrate the block-rsv code to block-rsv.c
  btrfs: stop using block_rsv_release_bytes everywhere
  btrfs: cleanup the target logic in __btrfs_block_rsv_release
  btrfs: export __btrfs_block_rsv_release
  btrfs: export btrfs_block_rsv_add_bytes
  btrfs: move btrfs_block_rsv definitions into it's own header
  btrfs: Simplify update of space_info in __reserve_metadata_bytes()
  btrfs: unexport can_overcommit
  btrfs: move reserve_metadata_bytes and supporting code to space-info.c
  btrfs: move dump_space_info to space-info.c
  btrfs: export block_rsv_use_bytes
  btrfs: move btrfs_space_info_add_*_bytes to space-info.c
  btrfs: move the space info update macro to space-info.h
  ...

1 files changed, 23 insertions, 0 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index cfeff1b8dce0..818f7ec8bb0e 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -43,6 +43,8 @@
 #include "qgroup.h"
 #include "tree-log.h"
 #include "compression.h"
+#include "space-info.h"
+#include "delalloc-space.h"
 
 #ifdef CONFIG_64BIT
 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
@@ -3993,6 +3995,27 @@ static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
 	if (!same_inode)
 		inode_dio_wait(inode_out);
 
+	/*
+	 * Workaround to make sure NOCOW buffered write reach disk as NOCOW.
+	 *
+	 * Btrfs' back references do not have a block level granularity, they
+	 * work at the whole extent level.
+	 * NOCOW buffered write without data space reserved may not be able
+	 * to fall back to CoW due to lack of data space, thus could cause
+	 * data loss.
+	 *
+	 * Here we take a shortcut by flushing the whole inode, so that all
+	 * nocow write should reach disk as nocow before we increase the
+	 * reference of the extent. We could do better by only flushing NOCOW
+	 * data, but that needs extra accounting.
+	 *
+	 * Also we don't need to check ASYNC_EXTENT, as async extent will be
+	 * CoWed anyway, not affecting nocow part.
+	 */
+	ret = filemap_flush(inode_in->i_mapping);
+	if (ret < 0)
+		return ret;
+
 	ret = btrfs_wait_ordered_range(inode_in, ALIGN_DOWN(pos_in, bs),
 				       wb_len);
 	if (ret < 0)