[PATCH 09/10] xfs: kill the dop_low flag

Christoph Hellwig
2017-04-13T08:06:05Z

Now that we always get our space reservations right in xfs_bmapi_write
we can remove the last remains of the dangerous low space allocator mode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/libxfs/xfs_bmap.c | 12 +-----------
fs/xfs/libxfs/xfs_bmap_btree.c | 2 --
fs/xfs/libxfs/xfs_defer.c | 1 -
fs/xfs/libxfs/xfs_defer.h | 15 ---------------
fs/xfs/xfs_filestream.c | 2 --
fs/xfs/xfs_trace.h | 12 +++---------
6 files changed, 4 insertions(+), 40 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index c06e7d500ed1..9e3f0e6a9062 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -762,9 +762,6 @@ xfs_bmap_extents_to_btree(
if (*firstblock == NULLFSBLOCK) {
args.type = XFS_ALLOCTYPE_START_BNO;
args.fsbno = XFS_INO_TO_FSB(mp, ip->i_ino);
- } else if (dfops->dop_low) {
- args.type = XFS_ALLOCTYPE_START_BNO;
- args.fsbno = *firstblock;
} else {
args.type = XFS_ALLOCTYPE_NEAR_BNO;
args.fsbno = *firstblock;
@@ -3677,12 +3674,6 @@ xfs_bmap_btalloc(
error = xfs_bmap_btalloc_nullfb(ap, &args, &blen);
if (error)
return error;
- } else if (ap->dfops->dop_low) {
- if (xfs_inode_is_filestream(ap->ip))
- args.type = XFS_ALLOCTYPE_FIRST_AG;
- else
- args.type = XFS_ALLOCTYPE_START_BNO;
- args.minlen = 1;
} else {
args.type = XFS_ALLOCTYPE_NEAR_BNO;
args.minlen = 1;
@@ -3709,7 +3700,7 @@ xfs_bmap_btalloc(
* is >= the stripe unit and the allocation offset is
* at the end of file.
*/
- if (!ap->dfops->dop_low && ap->aeof) {
+ if (ap->aeof) {
if (!ap->offset) {
args.alignment = stripe_align;
atype = args.type;
@@ -3816,7 +3807,6 @@ xfs_bmap_btalloc(
args.type = XFS_ALLOCTYPE_FIRST_AG;
if ((error = xfs_alloc_vextent(&args)))
return error;
- ap->dfops->dop_low = true;
}
if (args.fsbno != NULLFSBLOCK) {
/*
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index 153c969febd4..b9f0f61bd8ee 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -462,8 +462,6 @@ xfs_bmbt_alloc_block(
*/
if (xfs_trans_blk_res(args.tp))
args.minleft = xfs_trans_blk_res(args.tp) - args.maxlen;
- } else if (cur->bc_private.b.dfops->dop_low) {
- args.type = XFS_ALLOCTYPE_START_BNO;
} else {
args.type = XFS_ALLOCTYPE_NEAR_BNO;
}
diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c
index 5c2929f94bd3..172d583c6f1c 100644
--- a/fs/xfs/libxfs/xfs_defer.c
+++ b/fs/xfs/libxfs/xfs_defer.c
@@ -503,7 +503,6 @@ xfs_defer_init(
xfs_fsblock_t *fbp)
{
dop->dop_committed = false;
- dop->dop_low = false;
memset(&dop->dop_inodes, 0, sizeof(dop->dop_inodes));
*fbp = NULLFSBLOCK;
INIT_LIST_HEAD(&dop->dop_intake);
diff --git a/fs/xfs/libxfs/xfs_defer.h b/fs/xfs/libxfs/xfs_defer.h
index f6e93ef0bffe..cc1acd1fd4e8 100644
--- a/fs/xfs/libxfs/xfs_defer.h
+++ b/fs/xfs/libxfs/xfs_defer.h
@@ -36,20 +36,6 @@ struct xfs_defer_pending {
unsigned int dfp_count; /* # extent items */
};

-/*
- * Header for deferred operation list.
- *
- * dop_low is used by the allocator to activate the lowspace algorithm -
- * when free space is running low the extent allocator may choose to
- * allocate an extent from an AG without leaving sufficient space for
- * a btree split when inserting the new extent. In this case the allocator
- * will enable the lowspace algorithm which is supposed to allow further
- * allocations (such as btree splits and newroots) to allocate from
- * sequential AGs. In order to avoid locking AGs out of order the lowspace
- * algorithm will start searching for free space from AG 0. If the correct
- * transaction reservations have been made then this algorithm will eventually
- * find all the space it needs.
- */
enum xfs_defer_ops_type {
XFS_DEFER_OPS_TYPE_BMAP,
XFS_DEFER_OPS_TYPE_REFCOUNT,
@@ -62,7 +48,6 @@ enum xfs_defer_ops_type {

struct xfs_defer_ops {
bool dop_committed; /* did any trans commit? */
- bool dop_low; /* alloc in low mode */
struct list_head dop_intake; /* unlogged pending work */
struct list_head dop_pending; /* logged pending work */

diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c
index 043ca3808ea2..6d61e61c0700 100644
--- a/fs/xfs/xfs_filestream.c
+++ b/fs/xfs/xfs_filestream.c
@@ -390,8 +390,6 @@ xfs_filestream_new_ag(

if (xfs_alloc_is_userdata(ap->datatype))
flags |= XFS_PICK_USERDATA;
- if (ap->dfops->dop_low)
- flags |= XFS_PICK_LOWSPACE;

err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen);

diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index cba10daf8391..ab4ce20b00dd 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -2256,19 +2256,16 @@ DECLARE_EVENT_CLASS(xfs_defer_class,
__field(dev_t, dev)
__field(void *, dop)
__field(bool, committed)
- __field(bool, low)
),
TP_fast_assign(
__entry->dev = mp ? mp->m_super->s_dev : 0;
__entry->dop = dop;
__entry->committed = dop->dop_committed;
- __entry->low = dop->dop_low;
),
- TP_printk("dev %d:%d ops %p committed %d low %d\n",
+ TP_printk("dev %d:%d ops %p committed %d\n",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->dop,
- __entry->committed,
- __entry->low)
+ __entry->committed)
)
#define DEFINE_DEFER_EVENT(name) \
DEFINE_EVENT(xfs_defer_class, name, \
@@ -2282,21 +2279,18 @@ DECLARE_EVENT_CLASS(xfs_defer_error_class,
__field(dev_t, dev)
__field(void *, dop)
__field(bool, committed)
- __field(bool, low)
__field(int, error)
),
TP_fast_assign(
__entry->dev = mp ? mp->m_super->s_dev : 0;
__entry->dop = dop;
__entry->committed = dop->dop_committed;
- __entry->low = dop->dop_low;
__entry->error = error;
),
- TP_printk("dev %d:%d ops %p committed %d low %d err %d\n",
+ TP_printk("dev %d:%d ops %p committed %d err %d\n",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->dop,
__entry->committed,
- __entry->low,
__entry->error)
)
#define DEFINE_DEFER_ERROR_EVENT(name) \
--
2.11.0