xfs: flush speculative space allocations when we run out of spacereclaim-space-harder_2019-08-16

If a fs modification (creation, file write, reflink, etc.) is unable to
reserve enough space to handle the modification, try clearing whatever
space the filesystem might have been hanging onto in the hopes of
speeding up the filesystem.  The flushing behavior will become
particularly important when we add deferred inode inactivation because
that will increase the amount of space that isn't actively tied to user
data.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

8 files changed, 85 insertions, 12 deletions

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 090376c480d3..5ea1a84f77d9 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -944,7 +944,17 @@ xfs_alloc_file_space(
 retry:
 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks,
 				resrtextents, 0, &tp);
-
+		/*
+		 * We weren't able to reserve enough space to handle fallocate.
+		 * Flush any disk space that was being held in the hopes of
+		 * speeding up the filesystem.  We hold the IOLOCK so we cannot
+		 * do a synchronous scan.
+		 */
+		if (error == -ENOSPC && !cleared_space) {
+			cleared_space = true;
+			xfs_inode_free_blocks(ip->i_mount, false);
+			goto retry;
+		}
 		/*
 		 * Check for running out of space
 		 */
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index fd9dee4b58a3..fb42146ee8cf 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -654,15 +654,10 @@ write_retry:
 			goto write_retry;
 		iolock = 0;
 	} else if (ret == -ENOSPC && !cleared_space) {
-		struct xfs_eofblocks eofb = {0};
-
-		cleared_space = true;
 		xfs_flush_inodes(ip->i_mount);
-
 		xfs_iunlock(ip, iolock);
-		eofb.eof_flags = XFS_EOF_FLAGS_SYNC;
-		xfs_icache_free_eofblocks(ip->i_mount, &eofb);
-		xfs_icache_free_cowblocks(ip->i_mount, &eofb);
+		cleared_space = true;
+		xfs_inode_free_blocks(ip->i_mount, true);
 		goto write_retry;
 	}
 
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 6e4c3763d008..ed009d9413d9 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1524,6 +1524,15 @@ xfs_icache_free_eofblocks(
 			XFS_ICI_EOFBLOCKS_TAG);
 }
 
+static inline void
+xfs_inode_free_scan(
+	struct xfs_mount	*mp,
+	struct xfs_eofblocks	*eofb)
+{
+	xfs_icache_free_eofblocks(mp, eofb);
+	xfs_icache_free_cowblocks(mp, eofb);
+}
+
 /*
  * Run cow/eofblocks scans on the quotas applicable to the inode. For inodes
  * with multiple quotas, we don't know exactly which quota caused an allocation
@@ -1579,11 +1588,28 @@ xfs_inode_free_quota_blocks(
 
 	trace_xfs_inode_free_quota_blocks(ip->i_mount, &eofb, _RET_IP_);
 
-	xfs_icache_free_eofblocks(ip->i_mount, &eofb);
-	xfs_icache_free_cowblocks(ip->i_mount, &eofb);
+	xfs_inode_free_scan(ip->i_mount, &eofb);
 	return true;
 }
 
+/*
+ * Try to free space in the filesystem by purging eofblocks and cowblocks.
+ */
+void
+xfs_inode_free_blocks(
+	struct xfs_mount	*mp,
+	bool			sync)
+{
+	struct xfs_eofblocks	eofb = {0};
+
+	if (sync)
+		eofb.eof_flags |= XFS_EOF_FLAGS_SYNC;
+
+	trace_xfs_inode_free_blocks(mp, &eofb, _RET_IP_);
+
+	xfs_inode_free_scan(mp, &eofb);
+}
+
 static inline unsigned long
 xfs_iflag_for_tag(
 	int		tag)
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
index a42a682cec0b..738417c3568b 100644
--- a/fs/xfs/xfs_icache.h
+++ b/fs/xfs/xfs_icache.h
@@ -58,6 +58,7 @@ long xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan);
 void xfs_inode_set_reclaim_tag(struct xfs_inode *ip);
 
 bool xfs_inode_free_quota_blocks(struct xfs_inode *ip, bool sync);
+void xfs_inode_free_blocks(struct xfs_mount *mp, bool sync);
 
 void xfs_inode_set_eofblocks_tag(struct xfs_inode *ip);
 void xfs_inode_clear_eofblocks_tag(struct xfs_inode *ip);
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index dff7b1cd8424..ac4d7143abc2 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1171,10 +1171,17 @@ xfs_create(
 	 */
 retry:
 	error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
-	if (error == -ENOSPC) {
+	/*
+	 * We weren't able to reserve enough space to add the inode.  Flush
+	 * any disk space that was being held in the hopes of speeding up the
+	 * filesystem.
+	 */
+	if (error == -ENOSPC && !cleared_space) {
+		cleared_space = true;
 		/* flush outstanding delalloc blocks and retry */
 		xfs_flush_inodes(mp);
-		error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
+		xfs_inode_free_blocks(mp, true);
+		goto retry;
 	}
 	if (error)
 		goto out_release_inode;
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 58b3ec6b00e3..2a6a2bbb4c63 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -262,6 +262,18 @@ xfs_iomap_write_direct(
 retry:
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, resrtextents,
 			tflags, &tp);
+	/*
+	 * We weren't able to reserve enough space for the direct write.  Flush
+	 * any disk space that was being held in the hopes of speeding up the
+	 * filesystem.  Historically, we expected callers to have preallocated
+	 * all the space before a direct write, but this is not an absolute
+	 * requirement.  We still hold the IOLOCK so we cannot do a sync scan.
+	 */
+	if (error == -ENOSPC && !cleared_space) {
+		cleared_space = true;
+		xfs_inode_free_blocks(ip->i_mount, false);
+		goto retry;
+	}
 	if (error)
 		return error;
 
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 4ab483483a31..c62bf4a35de3 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -381,6 +381,17 @@ xfs_reflink_allocate_cow(
 	xfs_iunlock(ip, *lockmode);
 retry:
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
+	/*
+	 * We weren't able to reserve enough space to handle copy on write.
+	 * Flush any disk space that was being held in the hopes of speeding up
+	 * the filesystem.  We potentially hold the IOLOCK so we cannot do a
+	 * synchronous scan.
+	 */
+	if (error == -ENOSPC && !cleared_space) {
+		cleared_space = true;
+		xfs_inode_free_blocks(ip->i_mount, false);
+		goto retry;
+	}
 	*lockmode = XFS_ILOCK_EXCL;
 	xfs_ilock(ip, *lockmode);
 
@@ -1043,6 +1054,16 @@ xfs_reflink_remap_extent(
 	resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK);
 retry:
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
+	/*
+	 * We weren't able to reserve enough space for the remapping.  Flush
+	 * any disk space that was being held in the hopes of speeding up the
+	 * filesystem.  We still hold the IOLOCK so we cannot do a sync scan.
+	 */
+	if (error == -ENOSPC && !cleared_space) {
+		cleared_space = true;
+		xfs_inode_free_blocks(mp, false);
+		goto retry;
+	}
 	if (error)
 		goto out;
 
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index ddf5695209ea..2c289e24a9a8 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -3760,6 +3760,7 @@ DEFINE_EVENT(xfs_eofblocks_class, name,	\
 	TP_ARGS(mp, eofb, caller_ip))
 DEFINE_EOFBLOCKS_EVENT(xfs_ioc_free_eofblocks);
 DEFINE_EOFBLOCKS_EVENT(xfs_inode_free_quota_blocks);
+DEFINE_EOFBLOCKS_EVENT(xfs_inode_free_blocks);
 
 #endif /* _TRACE_XFS_H */