Merge tag 'xfs-5.1-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Darrick Wong:
 "Here are a number of new features and bug fixes for 5.1

  They've undergone a week's worth of fstesting and merge cleanly with
  master as of this morning

  Most of the changes center on improving metadata validation and fixing
  problems with online fsck, though there's also a new cache to speed up
  unlinked inode handling and cleanup of the copy on write code in
  preparation for future features

  Changes for Linux 5.1:

   - Fix online fsck to handle inode btrees correctly on 64k block
     filesystems

   - Teach online fsck to check directory and attribute names for
     invalid characters

   - Miscellanous fixes for online fsck

   - Introduce a new panic mask so that we can halt immediately on
     metadata corruption (for debugging purposes)

   - Fix a block mapping race during writeback

   - Cache unlinked inode list backrefs in memory to speed up list
     processing

   - Separate the bnobt/cntbt and inobt/finobt buffer verifiers so that
     we can detect crosslinked btrees

   - Refactor magic number verification so that we can standardize it

   - Strengthen ondisk metadata structure offset build time verification

   - Fix a memory corruption problem in the listxattr code

   - Fix a shutdown problem during log recovery due to unreserved finobt
     expansion

   - Fix a referential integrity problem where O_TMPFILE inodes were put
     on the unlinked list with nlink > 0 which would cause asserts
     during log recovery if the system went down immediately

   - Refactor the delayed allocation allocator to be more clever about
     the possibility that its mapping might be stale

   - Various fixes to the copy on write mechanism

   - Make CoW preallocation suitable for use even with writes that
     wouldn't otherwise require it

   - Refactor an internal API

   - Fix some statx implementation bugs

   - Fix miscellaneous compiler and static checker complaints"

* tag 'xfs-5.1-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (70 commits)
  xfs: fix reporting supported extra file attributes for statx()
  xfs: fix backwards endian conversion in scrub
  xfs: fix uninitialized error variables
  xfs: rework breaking of shared extents in xfs_file_iomap_begin
  xfs: don't pass iomap flags to xfs_reflink_allocate_cow
  xfs: fix uninitialized error variable
  xfs: introduce an always_cow mode
  xfs: report IOMAP_F_SHARED from xfs_file_iomap_begin_delay
  xfs: make COW fork unwritten extent conversions more robust
  xfs: merge COW handling into xfs_file_iomap_begin_delay
  xfs: also truncate holes covered by COW blocks
  xfs: don't use delalloc extents for COW on files with extsize hints
  xfs: fix SEEK_DATA for speculative COW fork preallocation
  xfs: make xfs_bmbt_to_iomap more useful
  xfs: fix xfs_buf magic number endian checks
  xfs: retry COW fork delalloc conversion when no extent was found
  xfs: remove the truncate short cut in xfs_map_blocks
  xfs: move xfs_iomap_write_allocate to xfs_aops.c
  xfs: move stat accounting to xfs_bmapi_convert_delalloc
  xfs: move transaction handling to xfs_bmapi_convert_delalloc
  ..

1 files changed, 22 insertions, 9 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index e47425071e65..770cc2edf777 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -507,7 +507,7 @@ xfs_file_dio_aio_write(
 		 * We can't properly handle unaligned direct I/O to reflink
 		 * files yet, as we can't unshare a partial block.
 		 */
-		if (xfs_is_reflink_inode(ip)) {
+		if (xfs_is_cow_inode(ip)) {
 			trace_xfs_reflink_bounce_dio_write(ip, iocb->ki_pos, count);
 			return -EREMCHG;
 		}
@@ -872,14 +872,27 @@ xfs_file_fallocate(
 				goto out_unlock;
 		}
 
-		if (mode & FALLOC_FL_ZERO_RANGE)
+		if (mode & FALLOC_FL_ZERO_RANGE) {
 			error = xfs_zero_file_space(ip, offset, len);
-		else {
-			if (mode & FALLOC_FL_UNSHARE_RANGE) {
-				error = xfs_reflink_unshare(ip, offset, len);
-				if (error)
-					goto out_unlock;
+		} else if (mode & FALLOC_FL_UNSHARE_RANGE) {
+			error = xfs_reflink_unshare(ip, offset, len);
+			if (error)
+				goto out_unlock;
+
+			if (!xfs_is_always_cow_inode(ip)) {
+				error = xfs_alloc_file_space(ip, offset, len,
+						XFS_BMAPI_PREALLOC);
 			}
+		} else {
+			/*
+			 * If always_cow mode we can't use preallocations and
+			 * thus should not create them.
+			 */
+			if (xfs_is_always_cow_inode(ip)) {
+				error = -EOPNOTSUPP;
+				goto out_unlock;
+			}
+
 			error = xfs_alloc_file_space(ip, offset, len,
 						     XFS_BMAPI_PREALLOC);
 		}
@@ -1068,10 +1081,10 @@ xfs_file_llseek(
 	default:
 		return generic_file_llseek(file, offset, whence);
 	case SEEK_HOLE:
-		offset = iomap_seek_hole(inode, offset, &xfs_iomap_ops);
+		offset = iomap_seek_hole(inode, offset, &xfs_seek_iomap_ops);
 		break;
 	case SEEK_DATA:
-		offset = iomap_seek_data(inode, offset, &xfs_iomap_ops);
+		offset = iomap_seek_data(inode, offset, &xfs_seek_iomap_ops);
 		break;
 	}