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, 52 insertions, 20 deletions

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 4f5f2ff3f70f..548344e25128 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -776,29 +776,24 @@ _xfs_buf_read(
 }
 
 /*
- * Set buffer ops on an unchecked buffer and validate it, if possible.
+ * Reverify a buffer found in cache without an attached ->b_ops.
  *
- * If the caller passed in an ops structure and the buffer doesn't have ops
- * assigned, set the ops and use them to verify the contents.  If the contents
- * cannot be verified, we'll clear XBF_DONE.  We assume the buffer has no
- * recorded errors and is already in XBF_DONE state.
+ * If the caller passed an ops structure and the buffer doesn't have ops
+ * assigned, set the ops and use it to verify the contents. If verification
+ * fails, clear XBF_DONE. We assume the buffer has no recorded errors and is
+ * already in XBF_DONE state on entry.
  *
- * Under normal operations, every in-core buffer must have buffer ops assigned
- * to them when the buffer is read in from disk so that we can validate the
- * metadata.
- *
- * However, there are two scenarios where one can encounter in-core buffers
- * that don't have buffer ops.  The first is during log recovery of buffers on
- * a V4 filesystem, though these buffers are purged at the end of recovery.
- *
- * The other is online repair, which tries to match arbitrary metadata blocks
- * with btree types in order to find the root.  If online repair doesn't match
- * the buffer with /any/ btree type, the buffer remains in memory in DONE state
- * with no ops, and a subsequent read_buf call from elsewhere will not set the
- * ops.  This function helps us fix this situation.
+ * Under normal operations, every in-core buffer is verified on read I/O
+ * completion. There are two scenarios that can lead to in-core buffers without
+ * an assigned ->b_ops. The first is during log recovery of buffers on a V4
+ * filesystem, though these buffers are purged at the end of recovery. The
+ * other is online repair, which intentionally reads with a NULL buffer ops to
+ * run several verifiers across an in-core buffer in order to establish buffer
+ * type.  If repair can't establish that, the buffer will be left in memory
+ * with NULL buffer ops.
  */
 int
-xfs_buf_ensure_ops(
+xfs_buf_reverify(
 	struct xfs_buf		*bp,
 	const struct xfs_buf_ops *ops)
 {
@@ -840,7 +835,7 @@ xfs_buf_read_map(
 		return bp;
 	}
 
-	xfs_buf_ensure_ops(bp, ops);
+	xfs_buf_reverify(bp, ops);
 
 	if (flags & XBF_ASYNC) {
 		/*
@@ -2209,3 +2204,40 @@ void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
 
 	atomic_set(&bp->b_lru_ref, lru_ref);
 }
+
+/*
+ * Verify an on-disk magic value against the magic value specified in the
+ * verifier structure. The verifier magic is in disk byte order so the caller is
+ * expected to pass the value directly from disk.
+ */
+bool
+xfs_verify_magic(
+	struct xfs_buf		*bp,
+	__be32			dmagic)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	int			idx;
+
+	idx = xfs_sb_version_hascrc(&mp->m_sb);
+	if (unlikely(WARN_ON(!bp->b_ops || !bp->b_ops->magic[idx])))
+		return false;
+	return dmagic == bp->b_ops->magic[idx];
+}
+/*
+ * Verify an on-disk magic value against the magic value specified in the
+ * verifier structure. The verifier magic is in disk byte order so the caller is
+ * expected to pass the value directly from disk.
+ */
+bool
+xfs_verify_magic16(
+	struct xfs_buf		*bp,
+	__be16			dmagic)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	int			idx;
+
+	idx = xfs_sb_version_hascrc(&mp->m_sb);
+	if (unlikely(WARN_ON(!bp->b_ops || !bp->b_ops->magic16[idx])))
+		return false;
+	return dmagic == bp->b_ops->magic16[idx];
+}