Merge tag 'xfs-6.12-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/x…

…fs-linux

Pull xfs fixes from Carlos Maiolino:

 - Fix integer overflow in xrep_bmap

 - Fix stale dealloc punching for COW IO

* tag 'xfs-6.12-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: punch delalloc extents from the COW fork for COW writes
  xfs: set IOMAP_F_SHARED for all COW fork allocations
  xfs: share more code in xfs_buffered_write_iomap_begin
  xfs: support the COW fork in xfs_bmap_punch_delalloc_range
  xfs: IOMAP_ZERO and IOMAP_UNSHARE already hold invalidate_lock
  xfs: take XFS_MMAPLOCK_EXCL xfs_file_write_zero_eof
  xfs: factor out a xfs_file_write_zero_eof helper
  iomap: move locking out of iomap_write_delalloc_release
  iomap: remove iomap_file_buffered_write_punch_delalloc
  iomap: factor out a iomap_last_written_block helper
  xfs: fix integer overflow in xrep_bmap

Documentation/filesystems/iomap/operations.rst

@@ -208,7 +208,7 @@ The filesystem must arrange to `cancel
 such `reservations
 <https://lore.kernel.org/linux-xfs/[email protected]/>`_
 because writeback will not consume the reservation.
-The ``iomap_file_buffered_write_punch_delalloc`` can be called from a
+The ``iomap_write_delalloc_release`` can be called from a
 ``->iomap_end`` function to find all the clean areas of the folios
 caching a fresh (``IOMAP_F_NEW``) delalloc mapping.
 It takes the ``invalidate_lock``.

fs/iomap/buffered-io.c

@@ -1145,10 +1145,36 @@ static void iomap_write_delalloc_scan(struct inode *inode,
 }
 
 /*
+ * When a short write occurs, the filesystem might need to use ->iomap_end
+ * to remove space reservations created in ->iomap_begin.
+ *
+ * For filesystems that use delayed allocation, there can be dirty pages over
+ * the delalloc extent outside the range of a short write but still within the
+ * delalloc extent allocated for this iomap if the write raced with page
+ * faults.
+ *
  * Punch out all the delalloc blocks in the range given except for those that
  * have dirty data still pending in the page cache - those are going to be
  * written and so must still retain the delalloc backing for writeback.
  *
+ * The punch() callback *must* only punch delalloc extents in the range passed
+ * to it. It must skip over all other types of extents in the range and leave
+ * them completely unchanged. It must do this punch atomically with respect to
+ * other extent modifications.
+ *
+ * The punch() callback may be called with a folio locked to prevent writeback
+ * extent allocation racing at the edge of the range we are currently punching.
+ * The locked folio may or may not cover the range being punched, so it is not
+ * safe for the punch() callback to lock folios itself.
+ *
+ * Lock order is:
+ *
+ * inode->i_rwsem (shared or exclusive)
+ *   inode->i_mapping->invalidate_lock (exclusive)
+ *     folio_lock()
+ *       ->punch
+ *         internal filesystem allocation lock
+ *
  * As we are scanning the page cache for data, we don't need to reimplement the
  * wheel - mapping_seek_hole_data() does exactly what we need to identify the
  * start and end of data ranges correctly even for sub-folio block sizes. This
@@ -1177,20 +1203,21 @@ static void iomap_write_delalloc_scan(struct inode *inode,
  * require sprinkling this code with magic "+ 1" and "- 1" arithmetic and expose
  * the code to subtle off-by-one bugs....
  */
-static void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte,
+void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte,
 		loff_t end_byte, unsigned flags, struct iomap *iomap,
 		iomap_punch_t punch)
 {
 	loff_t punch_start_byte = start_byte;
 	loff_t scan_end_byte = min(i_size_read(inode), end_byte);
 
 	/*
-	 * Lock the mapping to avoid races with page faults re-instantiating
-	 * folios and dirtying them via ->page_mkwrite whilst we walk the
-	 * cache and perform delalloc extent removal. Failing to do this can
-	 * leave dirty pages with no space reservation in the cache.
+	 * The caller must hold invalidate_lock to avoid races with page faults
+	 * re-instantiating folios and dirtying them via ->page_mkwrite whilst
+	 * we walk the cache and perform delalloc extent removal.  Failing to do
+	 * this can leave dirty pages with no space reservation in the cache.
 	 */
-	filemap_invalidate_lock(inode->i_mapping);
+	lockdep_assert_held_write(&inode->i_mapping->invalidate_lock);
+
 	while (start_byte < scan_end_byte) {
 		loff_t		data_end;
 
@@ -1207,7 +1234,7 @@ static void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte,
 		if (start_byte == -ENXIO || start_byte == scan_end_byte)
 			break;
 		if (WARN_ON_ONCE(start_byte < 0))
-			goto out_unlock;
+			return;
 		WARN_ON_ONCE(start_byte < punch_start_byte);
 		WARN_ON_ONCE(start_byte > scan_end_byte);
 
@@ -1218,7 +1245,7 @@ static void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte,
 		data_end = mapping_seek_hole_data(inode->i_mapping, start_byte,
 				scan_end_byte, SEEK_HOLE);
 		if (WARN_ON_ONCE(data_end < 0))
-			goto out_unlock;
+			return;
 
 		/*
 		 * If we race with post-direct I/O invalidation of the page cache,
@@ -1240,74 +1267,8 @@ static void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte,
 	if (punch_start_byte < end_byte)
 		punch(inode, punch_start_byte, end_byte - punch_start_byte,
 				iomap);
-out_unlock:
-	filemap_invalidate_unlock(inode->i_mapping);
-}
-
-/*
- * When a short write occurs, the filesystem may need to remove reserved space
- * that was allocated in ->iomap_begin from it's ->iomap_end method. For
- * filesystems that use delayed allocation, we need to punch out delalloc
- * extents from the range that are not dirty in the page cache. As the write can
- * race with page faults, there can be dirty pages over the delalloc extent
- * outside the range of a short write but still within the delalloc extent
- * allocated for this iomap.
- *
- * This function uses [start_byte, end_byte) intervals (i.e. open ended) to
- * simplify range iterations.
- *
- * The punch() callback *must* only punch delalloc extents in the range passed
- * to it. It must skip over all other types of extents in the range and leave
- * them completely unchanged. It must do this punch atomically with respect to
- * other extent modifications.
- *
- * The punch() callback may be called with a folio locked to prevent writeback
- * extent allocation racing at the edge of the range we are currently punching.
- * The locked folio may or may not cover the range being punched, so it is not
- * safe for the punch() callback to lock folios itself.
- *
- * Lock order is:
- *
- * inode->i_rwsem (shared or exclusive)
- *   inode->i_mapping->invalidate_lock (exclusive)
- *     folio_lock()
- *       ->punch
- *         internal filesystem allocation lock
- */
-void iomap_file_buffered_write_punch_delalloc(struct inode *inode,
-		loff_t pos, loff_t length, ssize_t written, unsigned flags,
-		struct iomap *iomap, iomap_punch_t punch)
-{
-	loff_t			start_byte;
-	loff_t			end_byte;
-	unsigned int		blocksize = i_blocksize(inode);
-
-	if (iomap->type != IOMAP_DELALLOC)
-		return;
-
-	/* If we didn't reserve the blocks, we're not allowed to punch them. */
-	if (!(iomap->flags & IOMAP_F_NEW))
-		return;
-
-	/*
-	 * start_byte refers to the first unused block after a short write. If
-	 * nothing was written, round offset down to point at the first block in
-	 * the range.
-	 */
-	if (unlikely(!written))
-		start_byte = round_down(pos, blocksize);
-	else
-		start_byte = round_up(pos + written, blocksize);
-	end_byte = round_up(pos + length, blocksize);
-
-	/* Nothing to do if we've written the entire delalloc extent */
-	if (start_byte >= end_byte)
-		return;
-
-	iomap_write_delalloc_release(inode, start_byte, end_byte, flags, iomap,
-			punch);
 }
-EXPORT_SYMBOL_GPL(iomap_file_buffered_write_punch_delalloc);
+EXPORT_SYMBOL_GPL(iomap_write_delalloc_release);
 
 static loff_t iomap_unshare_iter(struct iomap_iter *iter)
 {

fs/xfs/scrub/bmap_repair.c

@@ -801,7 +801,7 @@ xrep_bmap(
 {
 	struct xrep_bmap	*rb;
 	char			*descr;
-	unsigned int		max_bmbt_recs;
+	xfs_extnum_t		max_bmbt_recs;
 	bool			large_extcount;
 	int			error = 0;
 

fs/xfs/xfs_aops.c

@@ -116,7 +116,7 @@ xfs_end_ioend(
 	if (unlikely(error)) {
 		if (ioend->io_flags & IOMAP_F_SHARED) {
 			xfs_reflink_cancel_cow_range(ip, offset, size, true);
-			xfs_bmap_punch_delalloc_range(ip, offset,
+			xfs_bmap_punch_delalloc_range(ip, XFS_DATA_FORK, offset,
 					offset + size);
 		}
 		goto done;
@@ -456,7 +456,7 @@ xfs_discard_folio(
 	 * byte of the next folio. Hence the end offset is only dependent on the
 	 * folio itself and not the start offset that is passed in.
 	 */
-	xfs_bmap_punch_delalloc_range(ip, pos,
+	xfs_bmap_punch_delalloc_range(ip, XFS_DATA_FORK, pos,
 				folio_pos(folio) + folio_size(folio));
 }
 

fs/xfs/xfs_bmap_util.c

@@ -442,11 +442,12 @@ xfs_getbmap(
 void
 xfs_bmap_punch_delalloc_range(
 	struct xfs_inode	*ip,
+	int			whichfork,
 	xfs_off_t		start_byte,
 	xfs_off_t		end_byte)
 {
 	struct xfs_mount	*mp = ip->i_mount;
-	struct xfs_ifork	*ifp = &ip->i_df;
+	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
 	xfs_fileoff_t		start_fsb = XFS_B_TO_FSBT(mp, start_byte);
 	xfs_fileoff_t		end_fsb = XFS_B_TO_FSB(mp, end_byte);
 	struct xfs_bmbt_irec	got, del;
@@ -474,11 +475,14 @@ xfs_bmap_punch_delalloc_range(
 			continue;
 		}
 
-		xfs_bmap_del_extent_delay(ip, XFS_DATA_FORK, &icur, &got, &del);
+		xfs_bmap_del_extent_delay(ip, whichfork, &icur, &got, &del);
 		if (!xfs_iext_get_extent(ifp, &icur, &got))
 			break;
 	}
 
+	if (whichfork == XFS_COW_FORK && !ifp->if_bytes)
+		xfs_inode_clear_cowblocks_tag(ip);
+
 out_unlock:
 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 }
@@ -580,7 +584,7 @@ xfs_free_eofblocks(
 	 */
 	if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)) {
 		if (ip->i_delayed_blks) {
-			xfs_bmap_punch_delalloc_range(ip,
+			xfs_bmap_punch_delalloc_range(ip, XFS_DATA_FORK,
 				round_up(XFS_ISIZE(ip), mp->m_sb.sb_blocksize),
 				LLONG_MAX);
 		}

fs/xfs/xfs_bmap_util.h

@@ -30,7 +30,7 @@ xfs_bmap_rtalloc(struct xfs_bmalloca *ap)
 }
 #endif /* CONFIG_XFS_RT */
 
-void	xfs_bmap_punch_delalloc_range(struct xfs_inode *ip,
+void	xfs_bmap_punch_delalloc_range(struct xfs_inode *ip, int whichfork,
 		xfs_off_t start_byte, xfs_off_t end_byte);
 
 struct kgetbmap {