1 files changed, 270 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_metafile.c b/fs/xfs/libxfs/xfs_metafile.c
index adeb25d1a444..225923e463c4 100644
--- a/fs/xfs/libxfs/xfs_metafile.c
+++ b/fs/xfs/libxfs/xfs_metafile.c
@@ -17,6 +17,31 @@
 #include "xfs_metafile.h"
 #include "xfs_trace.h"
 #include "xfs_inode.h"
+#include "xfs_quota.h"
+#include "xfs_errortag.h"
+#include "xfs_error.h"
+#include "xfs_alloc.h"
+#include "xfs_rtgroup.h"
+#include "xfs_rtrmap_btree.h"
+#include "xfs_rtrefcount_btree.h"
+
+static const struct {
+	enum xfs_metafile_type	mtype;
+	const char		*name;
+} xfs_metafile_type_strs[] = { XFS_METAFILE_TYPE_STR };
+
+const char *
+xfs_metafile_type_str(enum xfs_metafile_type metatype)
+{
+	unsigned int	i;
+
+	for (i = 0; i < ARRAY_SIZE(xfs_metafile_type_strs); i++) {
+		if (xfs_metafile_type_strs[i].mtype == metatype)
+			return xfs_metafile_type_strs[i].name;
+	}
+
+	return NULL;
+}
 
 /* Set up an inode to be recognized as a metadata directory inode. */
 void
@@ -50,3 +75,248 @@ xfs_metafile_clear_iflag(
 	ip->i_diflags2 &= ~XFS_DIFLAG2_METADATA;
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 }
+
+/*
+ * Is the metafile reservations at or beneath a certain threshold?
+ */
+static inline bool
+xfs_metafile_resv_can_cover(
+	struct xfs_mount	*mp,
+	int64_t			rhs)
+{
+	/*
+	 * The amount of space that can be allocated to this metadata file is
+	 * the remaining reservation for the particular metadata file + the
+	 * global free block count.  Take care of the first case to avoid
+	 * touching the per-cpu counter.
+	 */
+	if (mp->m_metafile_resv_avail >= rhs)
+		return true;
+
+	/*
+	 * There aren't enough blocks left in the inode's reservation, but it
+	 * isn't critical unless there also isn't enough free space.
+	 */
+	return xfs_compare_freecounter(mp, XC_FREE_BLOCKS,
+			rhs - mp->m_metafile_resv_avail, 2048) >= 0;
+}
+
+/*
+ * Is the metafile reservation critically low on blocks?  For now we'll define
+ * that as the number of blocks we can get our hands on being less than 10% of
+ * what we reserved or less than some arbitrary number (maximum btree height).
+ */
+bool
+xfs_metafile_resv_critical(
+	struct xfs_mount	*mp)
+{
+	ASSERT(xfs_has_metadir(mp));
+
+	trace_xfs_metafile_resv_critical(mp, 0);
+
+	if (!xfs_metafile_resv_can_cover(mp, mp->m_rtbtree_maxlevels))
+		return true;
+
+	if (!xfs_metafile_resv_can_cover(mp,
+			div_u64(mp->m_metafile_resv_target, 10)))
+		return true;
+
+	return XFS_TEST_ERROR(false, mp, XFS_ERRTAG_METAFILE_RESV_CRITICAL);
+}
+
+/* Allocate a block from the metadata file's reservation. */
+void
+xfs_metafile_resv_alloc_space(
+	struct xfs_inode	*ip,
+	struct xfs_alloc_arg	*args)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	int64_t			len = args->len;
+
+	ASSERT(xfs_is_metadir_inode(ip));
+	ASSERT(args->resv == XFS_AG_RESV_METAFILE);
+
+	trace_xfs_metafile_resv_alloc_space(mp, args->len);
+
+	/*
+	 * Allocate the blocks from the metadata inode's block reservation
+	 * and update the ondisk sb counter.
+	 */
+	mutex_lock(&mp->m_metafile_resv_lock);
+	if (mp->m_metafile_resv_avail > 0) {
+		int64_t		from_resv;
+
+		from_resv = min_t(int64_t, len, mp->m_metafile_resv_avail);
+		mp->m_metafile_resv_avail -= from_resv;
+		xfs_mod_delalloc(ip, 0, -from_resv);
+		xfs_trans_mod_sb(args->tp, XFS_TRANS_SB_RES_FDBLOCKS,
+				-from_resv);
+		len -= from_resv;
+	}
+
+	/*
+	 * Any allocation in excess of the reservation requires in-core and
+	 * on-disk fdblocks updates.  If we can grab @len blocks from the
+	 * in-core fdblocks then all we need to do is update the on-disk
+	 * superblock; if not, then try to steal some from the transaction's
+	 * block reservation.  Overruns are only expected for rmap btrees.
+	 */
+	if (len) {
+		unsigned int	field;
+		int		error;
+
+		error = xfs_dec_fdblocks(ip->i_mount, len, true);
+		if (error)
+			field = XFS_TRANS_SB_FDBLOCKS;
+		else
+			field = XFS_TRANS_SB_RES_FDBLOCKS;
+
+		xfs_trans_mod_sb(args->tp, field, -len);
+	}
+
+	mp->m_metafile_resv_used += args->len;
+	mutex_unlock(&mp->m_metafile_resv_lock);
+
+	ip->i_nblocks += args->len;
+	xfs_trans_log_inode(args->tp, ip, XFS_ILOG_CORE);
+}
+
+/* Free a block to the metadata file's reservation. */
+void
+xfs_metafile_resv_free_space(
+	struct xfs_inode	*ip,
+	struct xfs_trans	*tp,
+	xfs_filblks_t		len)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	int64_t			to_resv;
+
+	ASSERT(xfs_is_metadir_inode(ip));
+
+	trace_xfs_metafile_resv_free_space(mp, len);
+
+	ip->i_nblocks -= len;
+	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+	mutex_lock(&mp->m_metafile_resv_lock);
+	mp->m_metafile_resv_used -= len;
+
+	/*
+	 * Add the freed blocks back into the inode's delalloc reservation
+	 * until it reaches the maximum size.  Update the ondisk fdblocks only.
+	 */
+	to_resv = mp->m_metafile_resv_target -
+		(mp->m_metafile_resv_used + mp->m_metafile_resv_avail);
+	if (to_resv > 0) {
+		to_resv = min_t(int64_t, to_resv, len);
+		mp->m_metafile_resv_avail += to_resv;
+		xfs_mod_delalloc(ip, 0, to_resv);
+		xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FDBLOCKS, to_resv);
+		len -= to_resv;
+	}
+	mutex_unlock(&mp->m_metafile_resv_lock);
+
+	/*
+	 * Everything else goes back to the filesystem, so update the in-core
+	 * and on-disk counters.
+	 */
+	if (len)
+		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, len);
+}
+
+static void
+__xfs_metafile_resv_free(
+	struct xfs_mount	*mp)
+{
+	if (mp->m_metafile_resv_avail) {
+		xfs_mod_sb_delalloc(mp, -(int64_t)mp->m_metafile_resv_avail);
+		xfs_add_fdblocks(mp, mp->m_metafile_resv_avail);
+	}
+	mp->m_metafile_resv_avail = 0;
+	mp->m_metafile_resv_used = 0;
+	mp->m_metafile_resv_target = 0;
+}
+
+/* Release unused metafile space reservation. */
+void
+xfs_metafile_resv_free(
+	struct xfs_mount	*mp)
+{
+	if (!xfs_has_metadir(mp))
+		return;
+
+	trace_xfs_metafile_resv_free(mp, 0);
+
+	mutex_lock(&mp->m_metafile_resv_lock);
+	__xfs_metafile_resv_free(mp);
+	mutex_unlock(&mp->m_metafile_resv_lock);
+}
+
+/* Set up a metafile space reservation. */
+int
+xfs_metafile_resv_init(
+	struct xfs_mount	*mp)
+{
+	struct xfs_rtgroup	*rtg = NULL;
+	xfs_filblks_t		used = 0, target = 0;
+	xfs_filblks_t		hidden_space;
+	xfs_rfsblock_t		dblocks_avail = mp->m_sb.sb_dblocks / 4;
+	int			error = 0;
+
+	if (!xfs_has_metadir(mp))
+		return 0;
+
+	/*
+	 * Free any previous reservation to have a clean slate.
+	 */
+	mutex_lock(&mp->m_metafile_resv_lock);
+	__xfs_metafile_resv_free(mp);
+
+	/*
+	 * Currently the only btree metafiles that require reservations are the
+	 * rtrmap and the rtrefcount.  Anything new will have to be added here
+	 * as well.
+	 */
+	while ((rtg = xfs_rtgroup_next(mp, rtg))) {
+		if (xfs_has_rtrmapbt(mp)) {
+			used += rtg_rmap(rtg)->i_nblocks;
+			target += xfs_rtrmapbt_calc_reserves(mp);
+		}
+		if (xfs_has_rtreflink(mp)) {
+			used += rtg_refcount(rtg)->i_nblocks;
+			target += xfs_rtrefcountbt_calc_reserves(mp);
+		}
+	}
+
+	if (!target)
+		goto out_unlock;
+
+	/*
+	 * Space taken by the per-AG metadata btrees are accounted on-disk as
+	 * used space.  We therefore only hide the space that is reserved but
+	 * not used by the trees.
+	 */
+	if (used > target)
+		target = used;
+	else if (target > dblocks_avail)
+		target = dblocks_avail;
+	hidden_space = target - used;
+
+	error = xfs_dec_fdblocks(mp, hidden_space, true);
+	if (error) {
+		trace_xfs_metafile_resv_init_error(mp, 0);
+		goto out_unlock;
+	}
+
+	xfs_mod_sb_delalloc(mp, hidden_space);
+
+	mp->m_metafile_resv_target = target;
+	mp->m_metafile_resv_used = used;
+	mp->m_metafile_resv_avail = hidden_space;
+
+	trace_xfs_metafile_resv_init(mp, target);
+
+out_unlock:
+	mutex_unlock(&mp->m_metafile_resv_lock);
+	return error;
+}