xfs: fix bogus minleft manipulations

commit 255c516278175a6dc7037d1406307f35237d8688 upstream.

We can't just set minleft to 0 when we're low on space - that's exactly
what we need minleft for: to protect space in the AG for btree block
allocations when we are low on free space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 8 insertions, 22 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 0a46f8488b8d..fe925702c955 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -2635,12 +2635,10 @@ xfs_alloc_vextent(
         xfs_agblock_t   agsize; /* allocation group size */
         int             error;
         int             flags;  /* XFS_ALLOC_FLAG_... locking flags */
-        xfs_extlen_t    minleft;/* minimum left value, temp copy */
         xfs_mount_t     *mp;    /* mount structure pointer */
         xfs_agnumber_t  sagno;  /* starting allocation group number */
         xfs_alloctype_t type;   /* input allocation type */
         int             bump_rotor = 0;
-        int             no_min = 0;
         xfs_agnumber_t  rotorstep = xfs_rotorstep; /* inode32 agf stepper */
 
         mp = args->mp;
@@ -2669,7 +2667,6 @@ xfs_alloc_vextent(
                 trace_xfs_alloc_vextent_badargs(args);
                 return 0;
         }
-        minleft = args->minleft;
 
         switch (type) {
         case XFS_ALLOCTYPE_THIS_AG:
@@ -2680,9 +2677,7 @@ xfs_alloc_vextent(
                  */
                 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
                 args->pag = xfs_perag_get(mp, args->agno);
-                args->minleft = 0;
                 error = xfs_alloc_fix_freelist(args, 0);
-                args->minleft = minleft;
                 if (error) {
                         trace_xfs_alloc_vextent_nofix(args);
                         goto error0;
@@ -2747,9 +2742,7 @@ xfs_alloc_vextent(
                  */
                 for (;;) {
                         args->pag = xfs_perag_get(mp, args->agno);
-                        if (no_min) args->minleft = 0;
                         error = xfs_alloc_fix_freelist(args, flags);
-                        args->minleft = minleft;
                         if (error) {
                                 trace_xfs_alloc_vextent_nofix(args);
                                 goto error0;
@@ -2789,20 +2782,17 @@ xfs_alloc_vextent(
                          * or switch to non-trylock mode.
                          */
                         if (args->agno == sagno) {
-                                if (no_min == 1) {
+                                if (flags == 0) {
                                         args->agbno = NULLAGBLOCK;
                                         trace_xfs_alloc_vextent_allfailed(args);
                                         break;
                                 }
-                                if (flags == 0) {
-                                        no_min = 1;
-                                } else {
-                                        flags = 0;
-                                        if (type == XFS_ALLOCTYPE_START_BNO) {
-                                                args->agbno = XFS_FSB_TO_AGBNO(mp,
-                                                        args->fsbno);
-                                                args->type = XFS_ALLOCTYPE_NEAR_BNO;
-                                        }
+
+                                flags = 0;
+                                if (type == XFS_ALLOCTYPE_START_BNO) {
+                                        args->agbno = XFS_FSB_TO_AGBNO(mp,
+                                                args->fsbno);
+                                        args->type = XFS_ALLOCTYPE_NEAR_BNO;
                                 }
                         }
                         xfs_perag_put(args->pag);
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 89d727b659fc..52dc5c175001 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -3903,7 +3903,6 @@ xfs_bmap_btalloc(
                 args.fsbno = 0;
                 args.type = XFS_ALLOCTYPE_FIRST_AG;
                 args.total = ap->minlen;
-                args.minleft = 0;
                 if ((error = xfs_alloc_vextent(&args)))
                         return error;
                 ap->dfops->dop_low = true;
@@ -4437,8 +4436,6 @@ xfs_bmapi_allocate(
         if (error)
                 return error;
 
-        if (bma->dfops->dop_low)
-                bma->minleft = 0;
         if (bma->cur)
                 bma->cur->bc_private.b.firstblock = *bma->firstblock;
         if (bma->blkno == NULLFSBLOCK)
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index 049fa597ae91..f76c1693ff01 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -502,12 +502,11 @@ try_another_ag:
         if (args.fsbno == NULLFSBLOCK && args.minleft) {
                 /*
                  * Could not find an AG with enough free space to satisfy
-                 * a full btree split.  Try again without minleft and if
+                 * a full btree split.  Try again and if
                  * successful activate the lowspace algorithm.
                  */
                 args.fsbno = 0;
                 args.type = XFS_ALLOCTYPE_FIRST_AG;
-                args.minleft = 0;
                 error = xfs_alloc_vextent(&args);
                 if (error)
                         goto error0;