[PATCH 20/42] xfs: use xfs_alloc_vextent_first_ag() where appropriate

Dave Chinner
2023-02-09T22:18:52Z

Change obvious callers of single AG allocation to use
xfs_alloc_vextent_first_ag(). This gets rid of
XFS_ALLOCTYPE_FIRST_AG as the type used within
xfs_alloc_vextent_first_ag() during iteration is _THIS_AG. Hence we
can remove the setting of args->type from all the callers of
_first_ag() and remove the alloctype.

While doing this, pass the allocation target fsb as a parameter
rather than encoding it in args->fsbno. This starts the process
of making args->fsbno an output only variable rather than
input/output.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/libxfs/xfs_alloc.c | 33 ++++++++++++++++++---------------
fs/xfs/libxfs/xfs_alloc.h | 10 ++++++++--
fs/xfs/libxfs/xfs_bmap.c | 31 ++++++++++++++++---------------
3 files changed, 42 insertions(+), 32 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 7e4452c11421..bd77e645398b 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -3183,7 +3183,8 @@ xfs_alloc_read_agf(
*/
static int
xfs_alloc_vextent_check_args(
- struct xfs_alloc_arg *args)
+ struct xfs_alloc_arg *args,
+ xfs_fsblock_t target)
{
struct xfs_mount *mp = args->mp;
xfs_agblock_t agsize;
@@ -3201,13 +3202,13 @@ xfs_alloc_vextent_check_args(
args->maxlen = agsize;
if (args->alignment == 0)
args->alignment = 1;
- ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
- ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
+ ASSERT(XFS_FSB_TO_AGNO(mp, target) < mp->m_sb.sb_agcount);
+ ASSERT(XFS_FSB_TO_AGBNO(mp, target) < agsize);
ASSERT(args->minlen <= args->maxlen);
ASSERT(args->minlen <= agsize);
ASSERT(args->mod < args->prod);
- if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
- XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
+ if (XFS_FSB_TO_AGNO(mp, target) >= mp->m_sb.sb_agcount ||
+ XFS_FSB_TO_AGBNO(mp, target) >= agsize ||
args->minlen > args->maxlen || args->minlen > agsize ||
args->mod >= args->prod) {
args->fsbno = NULLFSBLOCK;
@@ -3281,7 +3282,7 @@ xfs_alloc_vextent_this_ag(
if (args->tp->t_highest_agno != NULLAGNUMBER)
minimum_agno = args->tp->t_highest_agno;

- error = xfs_alloc_vextent_check_args(args);
+ error = xfs_alloc_vextent_check_args(args, args->fsbno);
if (error) {
if (error == -ENOSPC)
return 0;
@@ -3406,7 +3407,7 @@ xfs_alloc_vextent_start_ag(
bool bump_rotor = false;
int error;

- error = xfs_alloc_vextent_check_args(args);
+ error = xfs_alloc_vextent_check_args(args, args->fsbno);
if (error) {
if (error == -ENOSPC)
return 0;
@@ -3444,25 +3445,29 @@ xfs_alloc_vextent_start_ag(
* filesystem attempting blocking allocation. This does not wrap or try a second
* pass, so will not recurse into AGs lower than indicated by fsbno.
*/
-static int
+int
xfs_alloc_vextent_first_ag(
struct xfs_alloc_arg *args,
- xfs_agnumber_t minimum_agno)
-{
+ xfs_fsblock_t target)
+ {
struct xfs_mount *mp = args->mp;
+ xfs_agnumber_t minimum_agno = 0;
xfs_agnumber_t start_agno;
int error;

- error = xfs_alloc_vextent_check_args(args);
+ if (args->tp->t_highest_agno != NULLAGNUMBER)
+ minimum_agno = args->tp->t_highest_agno;
+
+ error = xfs_alloc_vextent_check_args(args, target);
if (error) {
if (error == -ENOSPC)
return 0;
return error;
}

- start_agno = max(minimum_agno, XFS_FSB_TO_AGNO(mp, args->fsbno));
-
+ start_agno = max(minimum_agno, XFS_FSB_TO_AGNO(mp, target));
args->type = XFS_ALLOCTYPE_THIS_AG;
+ args->fsbno = target;
error = xfs_alloc_vextent_iterate_ags(args, minimum_agno,
start_agno, 0);
xfs_alloc_vextent_set_fsbno(args, minimum_agno);
@@ -3495,8 +3500,6 @@ xfs_alloc_vextent(
break;
case XFS_ALLOCTYPE_START_BNO:
return xfs_alloc_vextent_start_ag(args, minimum_agno);
- case XFS_ALLOCTYPE_FIRST_AG:
- return xfs_alloc_vextent_first_ag(args, minimum_agno);
default:
error = -EFSCORRUPTED;
ASSERT(0);
diff --git a/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h
index 0a9ad6cd18e2..9be46f493340 100644
--- a/fs/xfs/libxfs/xfs_alloc.h
+++ b/fs/xfs/libxfs/xfs_alloc.h
@@ -19,7 +19,6 @@ unsigned int xfs_agfl_size(struct xfs_mount *mp);
/*
* Freespace allocation types. Argument to xfs_alloc_[v]extent.
*/
-#define XFS_ALLOCTYPE_FIRST_AG 0x02 /* ... start at ag 0 */
#define XFS_ALLOCTYPE_THIS_AG 0x08 /* anywhere in this a.g. */
#define XFS_ALLOCTYPE_START_BNO 0x10 /* near this block else anywhere */
#define XFS_ALLOCTYPE_NEAR_BNO 0x20 /* in this a.g. and near this block */
@@ -29,7 +28,6 @@ unsigned int xfs_agfl_size(struct xfs_mount *mp);
typedef unsigned int xfs_alloctype_t;

#define XFS_ALLOC_TYPES \
- { XFS_ALLOCTYPE_FIRST_AG, "FIRST_AG" }, \
{ XFS_ALLOCTYPE_THIS_AG, "THIS_AG" }, \
{ XFS_ALLOCTYPE_START_BNO, "START_BNO" }, \
{ XFS_ALLOCTYPE_NEAR_BNO, "NEAR_BNO" }, \
@@ -130,6 +128,14 @@ xfs_alloc_vextent(
*/
int xfs_alloc_vextent_this_ag(struct xfs_alloc_arg *args);

+/*
+ * Iterate from the AG indicated from args->fsbno through to the end of the
+ * filesystem attempting blocking allocation. This is for use in last
+ * resort allocation attempts when everything else has failed.
+ */
+int xfs_alloc_vextent_first_ag(struct xfs_alloc_arg *args,
+ xfs_fsblock_t target);
+
/*
* Free an extent.
*/
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index a28d57b82396..efca40fea8f1 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -3248,13 +3248,6 @@ xfs_bmap_btalloc_filestreams(
int notinit = 0;
int error;

- if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
- args->type = XFS_ALLOCTYPE_FIRST_AG;
- args->total = ap->minlen;
- args->minlen = ap->minlen;
- return 0;
- }
-
args->type = XFS_ALLOCTYPE_NEAR_BNO;
args->total = ap->total;

@@ -3462,9 +3455,7 @@ xfs_bmap_exact_minlen_extent_alloc(
*/
ap->blkno = XFS_AGB_TO_FSB(mp, 0, 0);

- args.fsbno = ap->blkno;
args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;
- args.type = XFS_ALLOCTYPE_FIRST_AG;
args.minlen = args.maxlen = ap->minlen;
args.total = ap->total;

@@ -3476,7 +3467,7 @@ xfs_bmap_exact_minlen_extent_alloc(
args.resv = XFS_AG_RESV_NONE;
args.datatype = ap->datatype;

- error = xfs_alloc_vextent(&args);
+ error = xfs_alloc_vextent_first_ag(&args, ap->blkno);
if (error)
return error;

@@ -3623,10 +3614,21 @@ xfs_bmap_btalloc_best_length(
* size to the largest space found.
*/
if ((ap->datatype & XFS_ALLOC_USERDATA) &&
- xfs_inode_is_filestream(ap->ip))
+ xfs_inode_is_filestream(ap->ip)) {
+ /*
+ * If there is very little free space before we start a
+ * filestreams allocation, we're almost guaranteed to fail to
+ * find an AG with enough contiguous free space to succeed, so
+ * just go straight to the low space algorithm.
+ */
+ if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
+ args->minlen = ap->minlen;
+ goto critically_low_space;
+ }
error = xfs_bmap_btalloc_filestreams(ap, args, &blen);
- else
+ } else {
error = xfs_bmap_btalloc_select_lengths(ap, args, &blen);
+ }
if (error)
return error;

@@ -3673,10 +3675,9 @@ xfs_bmap_btalloc_best_length(
* so they don't waste time on allocation modes that are unlikely to
* succeed.
*/
- args->fsbno = 0;
- args->type = XFS_ALLOCTYPE_FIRST_AG;
+critically_low_space:
args->total = ap->minlen;
- error = xfs_alloc_vextent(args);
+ error = xfs_alloc_vextent_first_ag(args, 0);
if (error)
return error;
ap->tp->t_flags |= XFS_TRANS_LOWMODE;
--
2.39.0