5 files changed, 46 insertions, 12 deletions

diff --git a/fs/xfs/libxfs/xfs_ag_resv.c b/fs/xfs/libxfs/xfs_ag_resv.c
index 0ca2e680034a..03885a968de8 100644
--- a/fs/xfs/libxfs/xfs_ag_resv.c
+++ b/fs/xfs/libxfs/xfs_ag_resv.c
@@ -326,6 +326,8 @@ xfs_ag_resv_alloc_extent(
         trace_xfs_ag_resv_alloc_extent(pag, type, args->len);
 
         switch (type) {
+        case XFS_AG_RESV_AGFL:
+                return;
         case XFS_AG_RESV_METADATA:
         case XFS_AG_RESV_RMAPBT:
                 resv = xfs_perag_resv(pag, type);
@@ -366,6 +368,8 @@ xfs_ag_resv_free_extent(
         trace_xfs_ag_resv_free_extent(pag, type, len);
 
         switch (type) {
+        case XFS_AG_RESV_AGFL:
+                return;
         case XFS_AG_RESV_METADATA:
         case XFS_AG_RESV_RMAPBT:
                 resv = xfs_perag_resv(pag, type);
diff --git a/fs/xfs/libxfs/xfs_ag_resv.h b/fs/xfs/libxfs/xfs_ag_resv.h
index 8d6c687deef3..938f2f96c5e8 100644
--- a/fs/xfs/libxfs/xfs_ag_resv.h
+++ b/fs/xfs/libxfs/xfs_ag_resv.h
@@ -32,4 +32,35 @@ void xfs_ag_resv_alloc_extent(struct xfs_perag *pag, enum xfs_ag_resv_type type,
 void xfs_ag_resv_free_extent(struct xfs_perag *pag, enum xfs_ag_resv_type type,
                 struct xfs_trans *tp, xfs_extlen_t len);
 
+/*
+ * RMAPBT reservation accounting wrappers. Since rmapbt blocks are sourced from
+ * the AGFL, they are allocated one at a time and the reservation updates don't
+ * require a transaction.
+ */
+static inline void
+xfs_ag_resv_rmapbt_alloc(
+        struct xfs_mount        *mp,
+        xfs_agnumber_t          agno)
+{
+        struct xfs_alloc_arg    args = {0};
+        struct xfs_perag        *pag;
+
+        args.len = 1;
+        pag = xfs_perag_get(mp, agno);
+        xfs_ag_resv_alloc_extent(pag, XFS_AG_RESV_RMAPBT, &args);
+        xfs_perag_put(pag);
+}
+
+static inline void
+xfs_ag_resv_rmapbt_free(
+        struct xfs_mount        *mp,
+        xfs_agnumber_t          agno)
+{
+        struct xfs_perag        *pag;
+
+        pag = xfs_perag_get(mp, agno);
+        xfs_ag_resv_free_extent(pag, XFS_AG_RESV_RMAPBT, NULL, 1);
+        xfs_perag_put(pag);
+}
+
 #endif  /* __XFS_AG_RESV_H__ */
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 1dc244d15a75..3db90b707fb2 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -728,7 +728,7 @@ xfs_alloc_ag_vextent(
 
         ASSERT(args->len >= args->minlen);
         ASSERT(args->len <= args->maxlen);
-        ASSERT(!args->wasfromfl || args->resv != XFS_AG_RESV_RMAPBT);
+        ASSERT(!args->wasfromfl || args->resv != XFS_AG_RESV_AGFL);
         ASSERT(args->agbno % args->alignment == 0);
 
         /* if not file data, insert new block into the reverse map btree */
@@ -1581,7 +1581,6 @@ xfs_alloc_ag_vextent_small(
         int             *stat)  /* status: 0-freelist, 1-normal/none */
 {
         struct xfs_owner_info   oinfo;
-        struct xfs_perag        *pag;
         int             error;
         xfs_agblock_t   fbno;
         xfs_extlen_t    flen;
@@ -1600,7 +1599,7 @@ xfs_alloc_ag_vextent_small(
          * freelist.
          */
         else if (args->minlen == 1 && args->alignment == 1 &&
-                 args->resv != XFS_AG_RESV_RMAPBT &&
+                 args->resv != XFS_AG_RESV_AGFL &&
                  (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
                   > args->minleft)) {
                 error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
@@ -1633,18 +1632,13 @@ xfs_alloc_ag_vextent_small(
                         /*
                          * If we're feeding an AGFL block to something that
                          * doesn't live in the free space, we need to clear
-                         * out the OWN_AG rmap and add the block back to
-                         * the RMAPBT per-AG reservation.
+                         * out the OWN_AG rmap.
                          */
                         xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG);
                         error = xfs_rmap_free(args->tp, args->agbp, args->agno,
                                         fbno, 1, &oinfo);
                         if (error)
                                 goto error0;
-                        pag = xfs_perag_get(args->mp, args->agno);
-                        xfs_ag_resv_free_extent(pag, XFS_AG_RESV_RMAPBT,
-                                        args->tp, 1);
-                        xfs_perag_put(pag);
 
                         *stat = 0;
                         return 0;
@@ -2170,7 +2164,7 @@ xfs_alloc_fix_freelist(
                 if (error)
                         goto out_agbp_relse;
                 error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1,
-                                           &targs.oinfo, XFS_AG_RESV_RMAPBT);
+                                           &targs.oinfo, XFS_AG_RESV_AGFL);
                 if (error)
                         goto out_agbp_relse;
                 bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
@@ -2196,7 +2190,7 @@ xfs_alloc_fix_freelist(
         while (pag->pagf_flcount < need) {
                 targs.agbno = 0;
                 targs.maxlen = need - pag->pagf_flcount;
-                targs.resv = XFS_AG_RESV_RMAPBT;
+                targs.resv = XFS_AG_RESV_AGFL;
 
                 /* Allocate as many blocks as possible at once. */
                 error = xfs_alloc_ag_vextent(&targs);
@@ -2877,7 +2871,7 @@ xfs_free_extent(
         int                     error;
 
         ASSERT(len != 0);
-        ASSERT(type != XFS_AG_RESV_RMAPBT);
+        ASSERT(type != XFS_AG_RESV_AGFL);
 
         if (XFS_TEST_ERROR(false, mp,
                         XFS_ERRTAG_FREE_EXTENT))
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c
index 738df3f9b5f2..8b0d0de1cd11 100644
--- a/fs/xfs/libxfs/xfs_rmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rmap_btree.c
@@ -125,6 +125,8 @@ xfs_rmapbt_alloc_block(
         be32_add_cpu(&agf->agf_rmap_blocks, 1);
         xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS);
 
+        xfs_ag_resv_rmapbt_alloc(cur->bc_mp, cur->bc_private.a.agno);
+
         *stat = 1;
         return 0;
 }
@@ -152,6 +154,8 @@ xfs_rmapbt_free_block(
                               XFS_EXTENT_BUSY_SKIP_DISCARD);
         xfs_trans_agbtree_delta(cur->bc_tp, -1);
 
+        xfs_ag_resv_rmapbt_free(cur->bc_mp, cur->bc_private.a.agno);
+
         return 0;
 }
 
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index a2cf3718bea9..1808f56decaa 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -325,6 +325,7 @@ xfs_daddr_to_agbno(struct xfs_mount *mp, xfs_daddr_t d)
 /* per-AG block reservation data structures*/
 enum xfs_ag_resv_type {
         XFS_AG_RESV_NONE = 0,
+        XFS_AG_RESV_AGFL,
         XFS_AG_RESV_METADATA,
         XFS_AG_RESV_RMAPBT,
 };