1 files changed, 55 insertions, 15 deletions

diff --git a/fs/xfs/libxfs/xfs_ag_resv.c b/fs/xfs/libxfs/xfs_ag_resv.c
index d346d42c54d1..33db69be4832 100644
--- a/fs/xfs/libxfs/xfs_ag_resv.c
+++ b/fs/xfs/libxfs/xfs_ag_resv.c
@@ -39,6 +39,7 @@
 #include "xfs_rmap_btree.h"
 #include "xfs_btree.h"
 #include "xfs_refcount_btree.h"
+#include "xfs_ialloc_btree.h"
 
 /*
  * Per-AG Block Reservations
@@ -200,22 +201,30 @@ __xfs_ag_resv_init(
         struct xfs_mount                *mp = pag->pag_mount;
         struct xfs_ag_resv              *resv;
         int                             error;
+        xfs_extlen_t                    reserved;
 
-        resv = xfs_perag_resv(pag, type);
         if (used > ask)
                 ask = used;
-        resv->ar_asked = ask;
-        resv->ar_reserved = resv->ar_orig_reserved = ask - used;
-        mp->m_ag_max_usable -= ask;
+        reserved = ask - used;
 
-        trace_xfs_ag_resv_init(pag, type, ask);
-
-        error = xfs_mod_fdblocks(mp, -(int64_t)resv->ar_reserved, true);
-        if (error)
+        error = xfs_mod_fdblocks(mp, -(int64_t)reserved, true);
+        if (error) {
                 trace_xfs_ag_resv_init_error(pag->pag_mount, pag->pag_agno,
                                 error, _RET_IP_);
+                xfs_warn(mp,
+"Per-AG reservation for AG %u failed.  Filesystem may run out of space.",
+                                pag->pag_agno);
+                return error;
+        }
 
-        return error;
+        mp->m_ag_max_usable -= ask;
+
+        resv = xfs_perag_resv(pag, type);
+        resv->ar_asked = ask;
+        resv->ar_reserved = resv->ar_orig_reserved = reserved;
+
+        trace_xfs_ag_resv_init(pag, type, ask);
+        return 0;
 }
 
 /* Create a per-AG block reservation. */
@@ -223,6 +232,8 @@ int
 xfs_ag_resv_init(
         struct xfs_perag                *pag)
 {
+        struct xfs_mount                *mp = pag->pag_mount;
+        xfs_agnumber_t                  agno = pag->pag_agno;
         xfs_extlen_t                    ask;
         xfs_extlen_t                    used;
         int                             error = 0;
@@ -231,23 +242,45 @@ xfs_ag_resv_init(
         if (pag->pag_meta_resv.ar_asked == 0) {
                 ask = used = 0;
 
-                error = xfs_refcountbt_calc_reserves(pag->pag_mount,
-                                pag->pag_agno, &ask, &used);
+                error = xfs_refcountbt_calc_reserves(mp, agno, &ask, &used);
                 if (error)
                         goto out;
 
-                error = __xfs_ag_resv_init(pag, XFS_AG_RESV_METADATA,
-                                ask, used);
+                error = xfs_finobt_calc_reserves(mp, agno, &ask, &used);
                 if (error)
                         goto out;
+
+                error = __xfs_ag_resv_init(pag, XFS_AG_RESV_METADATA,
+                                ask, used);
+                if (error) {
+                        /*
+                         * Because we didn't have per-AG reservations when the
+                         * finobt feature was added we might not be able to
+                         * reserve all needed blocks.  Warn and fall back to the
+                         * old and potentially buggy code in that case, but
+                         * ensure we do have the reservation for the refcountbt.
+                         */
+                        ask = used = 0;
+
+                        mp->m_inotbt_nores = true;
+
+                        error = xfs_refcountbt_calc_reserves(mp, agno, &ask,
+                                        &used);
+                        if (error)
+                                goto out;
+
+                        error = __xfs_ag_resv_init(pag, XFS_AG_RESV_METADATA,
+                                        ask, used);
+                        if (error)
+                                goto out;
+                }
         }
 
         /* Create the AGFL metadata reservation */
         if (pag->pag_agfl_resv.ar_asked == 0) {
                 ask = used = 0;
 
-                error = xfs_rmapbt_calc_reserves(pag->pag_mount, pag->pag_agno,
-                                &ask, &used);
+                error = xfs_rmapbt_calc_reserves(mp, agno, &ask, &used);
                 if (error)
                         goto out;
 
@@ -256,9 +289,16 @@ xfs_ag_resv_init(
                         goto out;
         }
 
+#ifdef DEBUG
+        /* need to read in the AGF for the ASSERT below to work */
+        error = xfs_alloc_pagf_init(pag->pag_mount, NULL, pag->pag_agno, 0);
+        if (error)
+                return error;
+
         ASSERT(xfs_perag_resv(pag, XFS_AG_RESV_METADATA)->ar_reserved +
                xfs_perag_resv(pag, XFS_AG_RESV_AGFL)->ar_reserved <=
                pag->pagf_freeblks + pag->pagf_flcount);
+#endif
 out:
         return error;
 }