1 files changed, 57 insertions, 56 deletions

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index bb590a267a7f..b9a8c3798e08 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -352,22 +352,10 @@ xfs_quota_calc_throttle(
 }
 
 /*
- * If we are doing a write at the end of the file and there are no allocations
- * past this one, then extend the allocation out to the file system's write
- * iosize.
- *
  * If we don't have a user specified preallocation size, dynamically increase
  * the preallocation size as the size of the file grows.  Cap the maximum size
  * at a single extent or less if the filesystem is near full. The closer the
- * filesystem is to full, the smaller the maximum prealocation.
- *
- * As an exception we don't do any preallocation at all if the file is smaller
- * than the minimum preallocation and we are using the default dynamic
- * preallocation scheme, as it is likely this is the only write to the file that
- * is going to be done.
- *
- * We clean up any extra space left over when the file is closed in
- * xfs_inactive().
+ * filesystem is to being full, the smaller the maximum preallocation.
  */
 STATIC xfs_fsblock_t
 xfs_iomap_prealloc_size(
@@ -377,63 +365,70 @@ xfs_iomap_prealloc_size(
 	loff_t			count,
 	struct xfs_iext_cursor	*icur)
 {
+	struct xfs_iext_cursor	ncur = *icur;
+	struct xfs_bmbt_irec	prev, got;
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
 	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
-	struct xfs_bmbt_irec	prev;
-	int			shift = 0;
 	int64_t			freesp;
 	xfs_fsblock_t		qblocks;
-	int			qshift = 0;
 	xfs_fsblock_t		alloc_blocks = 0;
+	xfs_extlen_t		plen;
+	int			shift = 0;
+	int			qshift = 0;
 
-	if (offset + count <= XFS_ISIZE(ip))
-		return 0;
-
-	if (!(mp->m_flags & XFS_MOUNT_ALLOCSIZE) &&
-	    (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_allocsize_blocks)))
+	/*
+	 * As an exception we don't do any preallocation at all if the file is
+	 * smaller than the minimum preallocation and we are using the default
+	 * dynamic preallocation scheme, as it is likely this is the only write
+	 * to the file that is going to be done.
+	 */
+	if (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_allocsize_blocks))
 		return 0;
 
 	/*
-	 * If an explicit allocsize is set, the file is small, or we
-	 * are writing behind a hole, then use the minimum prealloc:
+	 * Use the minimum preallocation size for small files or if we are
+	 * writing right after a hole.
 	 */
-	if ((mp->m_flags & XFS_MOUNT_ALLOCSIZE) ||
-	    XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) ||
-	    !xfs_iext_peek_prev_extent(ifp, icur, &prev) ||
+	if (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) ||
+	    !xfs_iext_prev_extent(ifp, &ncur, &prev) ||
 	    prev.br_startoff + prev.br_blockcount < offset_fsb)
 		return mp->m_allocsize_blocks;
 
 	/*
-	 * Determine the initial size of the preallocation. We are beyond the
-	 * current EOF here, but we need to take into account whether this is
-	 * a sparse write or an extending write when determining the
-	 * preallocation size.  Hence we need to look up the extent that ends
-	 * at the current write offset and use the result to determine the
-	 * preallocation size.
-	 *
-	 * If the extent is a hole, then preallocation is essentially disabled.
-	 * Otherwise we take the size of the preceding data extent as the basis
-	 * for the preallocation size. If the size of the extent is greater than
-	 * half the maximum extent length, then use the current offset as the
-	 * basis. This ensures that for large files the preallocation size
-	 * always extends to MAXEXTLEN rather than falling short due to things
-	 * like stripe unit/width alignment of real extents.
+	 * Take the size of the preceding data extents as the basis for the
+	 * preallocation size. Note that we don't care if the previous extents
+	 * are written or not.
 	 */
-	if (prev.br_blockcount <= (MAXEXTLEN >> 1))
-		alloc_blocks = prev.br_blockcount << 1;
-	else
+	plen = prev.br_blockcount;
+	while (xfs_iext_prev_extent(ifp, &ncur, &got)) {
+		if (plen > MAXEXTLEN / 2 ||
+		    isnullstartblock(got.br_startblock) ||
+		    got.br_startoff + got.br_blockcount != prev.br_startoff ||
+		    got.br_startblock + got.br_blockcount != prev.br_startblock)
+			break;
+		plen += got.br_blockcount;
+		prev = got;
+	}
+
+	/*
+	 * If the size of the extents is greater than half the maximum extent
+	 * length, then use the current offset as the basis.  This ensures that
+	 * for large files the preallocation size always extends to MAXEXTLEN
+	 * rather than falling short due to things like stripe unit/width
+	 * alignment of real extents.
+	 */
+	alloc_blocks = plen * 2;
+	if (alloc_blocks > MAXEXTLEN)
 		alloc_blocks = XFS_B_TO_FSB(mp, offset);
-	if (!alloc_blocks)
-		goto check_writeio;
 	qblocks = alloc_blocks;
 
 	/*
 	 * MAXEXTLEN is not a power of two value but we round the prealloc down
 	 * to the nearest power of two value after throttling. To prevent the
-	 * round down from unconditionally reducing the maximum supported prealloc
-	 * size, we round up first, apply appropriate throttling, round down and
-	 * cap the value to MAXEXTLEN.
+	 * round down from unconditionally reducing the maximum supported
+	 * prealloc size, we round up first, apply appropriate throttling,
+	 * round down and cap the value to MAXEXTLEN.
 	 */
 	alloc_blocks = XFS_FILEOFF_MIN(roundup_pow_of_two(MAXEXTLEN),
 				       alloc_blocks);
@@ -494,7 +489,6 @@ xfs_iomap_prealloc_size(
 	 */
 	while (alloc_blocks && alloc_blocks >= freesp)
 		alloc_blocks >>= 4;
-check_writeio:
 	if (alloc_blocks < mp->m_allocsize_blocks)
 		alloc_blocks = mp->m_allocsize_blocks;
 	trace_xfs_iomap_prealloc_size(ip, alloc_blocks, shift,
@@ -563,7 +557,7 @@ xfs_iomap_write_unwritten(
 		xfs_trans_ijoin(tp, ip, 0);
 
 		error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0,
-				XFS_QMOPT_RES_REGBLKS);
+				XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_FORCE_RES);
 		if (error)
 			goto error_on_bmapi_transaction;
 
@@ -856,7 +850,7 @@ xfs_buffered_write_iomap_begin(
 
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 
-	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ip, XFS_DATA_FORK)) ||
+	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(&ip->i_df)) ||
 	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
 		error = -EFSCORRUPTED;
 		goto out_unlock;
@@ -961,9 +955,16 @@ xfs_buffered_write_iomap_begin(
 	if (error)
 		goto out_unlock;
 
-	if (eof) {
-		prealloc_blocks = xfs_iomap_prealloc_size(ip, allocfork, offset,
-				count, &icur);
+	if (eof && offset + count > XFS_ISIZE(ip)) {
+		/*
+		 * Determine the initial size of the preallocation.
+		 * We clean up any extra preallocation when the file is closed.
+		 */
+		if (mp->m_flags & XFS_MOUNT_ALLOCSIZE)
+			prealloc_blocks = mp->m_allocsize_blocks;
+		else
+			prealloc_blocks = xfs_iomap_prealloc_size(ip, allocfork,
+						offset, count, &icur);
 		if (prealloc_blocks) {
 			xfs_extlen_t	align;
 			xfs_off_t	end_offset;
@@ -1258,12 +1259,12 @@ xfs_xattr_iomap_begin(
 	lockmode = xfs_ilock_attr_map_shared(ip);
 
 	/* if there are no attribute fork or extents, return ENOENT */
-	if (!XFS_IFORK_Q(ip) || !ip->i_d.di_anextents) {
+	if (!XFS_IFORK_Q(ip) || !ip->i_afp->if_nextents) {
 		error = -ENOENT;
 		goto out_unlock;
 	}
 
-	ASSERT(ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL);
+	ASSERT(ip->i_afp->if_format != XFS_DINODE_FMT_LOCAL);
 	error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
 			       &nimaps, XFS_BMAPI_ATTRFORK);
 out_unlock: