1 files changed, 78 insertions, 8 deletions

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index c101cf266bc4..7df74c35d9f9 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -39,6 +39,7 @@
 #include "xfs_health.h"
 #include "xfs_bmap_item.h"
 #include "xfs_symlink_remote.h"
+#include "xfs_inode_util.h"
 
 struct kmem_cache		*xfs_bmap_intent_cache;
 
@@ -604,7 +605,7 @@ xfs_bmap_btree_to_extents(
 
 	xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
 	error = xfs_free_extent_later(cur->bc_tp, cbno, 1, &oinfo,
-			XFS_AG_RESV_NONE, false);
+			XFS_AG_RESV_NONE, 0);
 	if (error)
 		return error;
 
@@ -4058,20 +4059,32 @@ xfs_bmapi_reserve_delalloc(
 	xfs_extlen_t		indlen;
 	uint64_t		fdblocks;
 	int			error;
-	xfs_fileoff_t		aoff = off;
+	xfs_fileoff_t		aoff;
+	bool			use_cowextszhint =
+					whichfork == XFS_COW_FORK && !prealloc;
 
+retry:
 	/*
 	 * Cap the alloc length. Keep track of prealloc so we know whether to
 	 * tag the inode before we return.
 	 */
+	aoff = off;
 	alen = XFS_FILBLKS_MIN(len + prealloc, XFS_MAX_BMBT_EXTLEN);
 	if (!eof)
 		alen = XFS_FILBLKS_MIN(alen, got->br_startoff - aoff);
 	if (prealloc && alen >= len)
 		prealloc = alen - len;
 
-	/* Figure out the extent size, adjust alen */
-	if (whichfork == XFS_COW_FORK) {
+	/*
+	 * If we're targetting the COW fork but aren't creating a speculative
+	 * posteof preallocation, try to expand the reservation to align with
+	 * the COW extent size hint if there's sufficient free space.
+	 *
+	 * Unlike the data fork, the CoW cancellation functions will free all
+	 * the reservations at inactivation, so we don't require that every
+	 * delalloc reservation have a dirty pagecache.
+	 */
+	if (use_cowextszhint) {
 		struct xfs_bmbt_irec	prev;
 		xfs_extlen_t		extsz = xfs_get_cowextsz_hint(ip);
 
@@ -4090,7 +4103,7 @@ xfs_bmapi_reserve_delalloc(
 	 */
 	error = xfs_quota_reserve_blkres(ip, alen);
 	if (error)
-		return error;
+		goto out;
 
 	/*
 	 * Split changing sb for alen and indlen since they could be coming
@@ -4140,6 +4153,17 @@ out_unreserve_frextents:
 out_unreserve_quota:
 	if (XFS_IS_QUOTA_ON(mp))
 		xfs_quota_unreserve_blkres(ip, alen);
+out:
+	if (error == -ENOSPC || error == -EDQUOT) {
+		trace_xfs_delalloc_enospc(ip, off, len);
+
+		if (prealloc || use_cowextszhint) {
+			/* retry without any preallocation */
+			use_cowextszhint = false;
+			prealloc = 0;
+			goto retry;
+		}
+	}
 	return error;
 }
 
@@ -5357,11 +5381,15 @@ xfs_bmap_del_extent_real(
 			error = xfs_rtfree_blocks(tp, del->br_startblock,
 					del->br_blockcount);
 		} else {
+			unsigned int	efi_flags = 0;
+
+			if ((bflags & XFS_BMAPI_NODISCARD) ||
+			    del->br_state == XFS_EXT_UNWRITTEN)
+				efi_flags |= XFS_FREE_EXTENT_SKIP_DISCARD;
+
 			error = xfs_free_extent_later(tp, del->br_startblock,
 					del->br_blockcount, NULL,
-					XFS_AG_RESV_NONE,
-					((bflags & XFS_BMAPI_NODISCARD) ||
-					del->br_state == XFS_EXT_UNWRITTEN));
+					XFS_AG_RESV_NONE, efi_flags);
 		}
 		if (error)
 			return error;
@@ -6431,3 +6459,45 @@ xfs_bmap_query_all(
 
 	return xfs_btree_query_all(cur, xfs_bmap_query_range_helper, &query);
 }
+
+/* Helper function to extract extent size hint from inode */
+xfs_extlen_t
+xfs_get_extsz_hint(
+	struct xfs_inode	*ip)
+{
+	/*
+	 * No point in aligning allocations if we need to COW to actually
+	 * write to them.
+	 */
+	if (xfs_is_always_cow_inode(ip))
+		return 0;
+	if ((ip->i_diflags & XFS_DIFLAG_EXTSIZE) && ip->i_extsize)
+		return ip->i_extsize;
+	if (XFS_IS_REALTIME_INODE(ip) &&
+	    ip->i_mount->m_sb.sb_rextsize > 1)
+		return ip->i_mount->m_sb.sb_rextsize;
+	return 0;
+}
+
+/*
+ * Helper function to extract CoW extent size hint from inode.
+ * Between the extent size hint and the CoW extent size hint, we
+ * return the greater of the two.  If the value is zero (automatic),
+ * use the default size.
+ */
+xfs_extlen_t
+xfs_get_cowextsz_hint(
+	struct xfs_inode	*ip)
+{
+	xfs_extlen_t		a, b;
+
+	a = 0;
+	if (ip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE)
+		a = ip->i_cowextsize;
+	b = xfs_get_extsz_hint(ip);
+
+	a = max(a, b);
+	if (a == 0)
+		return XFS_DEFAULT_COWEXTSZ_HINT;
+	return a;
+}