xfs: pass perags around in fsmap data dev functions

Needs a [from, to] ranged AG walk, and the perag to be stuffed into
the info structure for callouts to use.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/fs/xfs/libxfs/xfs_ag.h b/fs/xfs/libxfs/xfs_ag.h
index f87a60a4a8492a1b1ddf709e51a147ff4b8081f8..ebf997a8684e2ea34e18552eecbc689950be2d7d 100644 (file)
--- a/fs/xfs/libxfs/xfs_ag.h
+++ b/fs/xfs/libxfs/xfs_ag.h
@@ -116,14 +116,25 @@ void      xfs_perag_put(struct xfs_perag *pag);
 
 /*
  * Perag iteration APIs
+ *
+ * XXX: for_each_perag_range() usage really needs an iterator to clean up when
+ * we terminate at end_agno because we may have taken a reference to the perag
+ * beyond end_agno. Right now callers have to be careful to catch and clean that
+ * up themselves. This is not necessary for the callers of for_each_perag() and
+ * for_each_perag_from() because they terminate at sb_agcount where there are
+ * no perag structures in tree beyond end_agno.
  */
-#define for_each_perag_from(mp, next_agno, pag) \
+#define for_each_perag_range(mp, next_agno, end_agno, pag) \
        for ((pag) = xfs_perag_get((mp), (next_agno)); \
-               (pag) != NULL; \
+               (pag) != NULL && (next_agno) <= (end_agno); \
                (next_agno) = (pag)->pag_agno + 1, \
                xfs_perag_put(pag), \
                (pag) = xfs_perag_get((mp), (next_agno)))
 
+#define for_each_perag_from(mp, next_agno, pag) \
+       for_each_perag_range((mp), (next_agno), (mp)->m_sb.sb_agcount, (pag))
+
+
 #define for_each_perag(mp, agno, pag) \
        (agno) = 0; \
        for_each_perag_from((mp), (agno), (pag))

diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c
index 34f2b971ce439ce35921b200b3609ef172bc40fb..835dd6e3819be7e07e560b4b48251e0bf064ded5 100644 (file)
--- a/fs/xfs/xfs_fsmap.c
+++ b/fs/xfs/xfs_fsmap.c
@@ -24,6 +24,7 @@
 #include "xfs_refcount_btree.h"
 #include "xfs_alloc_btree.h"
 #include "xfs_rtalloc.h"
+#include "xfs_ag.h"
 
 /* Convert an xfs_fsmap to an fsmap. */
 static void
@@ -157,10 +158,10 @@ struct xfs_getfsmap_info {
        struct xfs_fsmap_head   *head;
        struct fsmap            *fsmap_recs;    /* mapping records */
        struct xfs_buf          *agf_bp;        /* AGF, for refcount queries */
+       struct xfs_perag        *pag;           /* AG info, if applicable */
        xfs_daddr_t             next_daddr;     /* next daddr we expect */
        u64                     missing_owner;  /* owner of holes */
        u32                     dev;            /* device id */
-       xfs_agnumber_t          agno;           /* AG number, if applicable */
        struct xfs_rmap_irec    low;            /* low rmap key */
        struct xfs_rmap_irec    high;           /* high rmap key */
        bool                    last;           /* last extent? */
@@ -203,14 +204,14 @@ xfs_getfsmap_is_shared(
        *stat = false;
        if (!xfs_sb_version_hasreflink(&mp->m_sb))
                return 0;
-       /* rt files will have agno set to NULLAGNUMBER */
-       if (info->agno == NULLAGNUMBER)
+       /* rt files will have no perag structure */
+       if (!info->pag)
                return 0;
 
        /* Are there any shared blocks here? */
        flen = 0;
        cur = xfs_refcountbt_init_cursor(mp, tp, info->agf_bp,
-                       info->agno);
+                       info->pag->pag_agno);
 
        error = xfs_refcount_find_shared(cur, rec->rm_startblock,
                        rec->rm_blockcount, &fbno, &flen, false);
@@ -311,7 +312,8 @@ xfs_getfsmap_helper(
        if (info->head->fmh_entries >= info->head->fmh_count)
                return -ECANCELED;
 
-       trace_xfs_fsmap_mapping(mp, info->dev, info->agno, rec);
+       trace_xfs_fsmap_mapping(mp, info->dev,
+                       info->pag ? info->pag->pag_agno : NULLAGNUMBER, rec);
 
        fmr.fmr_device = info->dev;
        fmr.fmr_physical = rec_daddr;
@@ -429,8 +431,8 @@ xfs_getfsmap_logdev(
        info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS;
        info->missing_owner = XFS_FMR_OWN_FREE;
 
-       trace_xfs_fsmap_low_key(mp, info->dev, info->agno, &info->low);
-       trace_xfs_fsmap_high_key(mp, info->dev, info->agno, &info->high);
+       trace_xfs_fsmap_low_key(mp, info->dev, NULLAGNUMBER, &info->low);
+       trace_xfs_fsmap_high_key(mp, info->dev, NULLAGNUMBER, &info->high);
 
        if (keys[0].fmr_physical > 0)
                return 0;
@@ -508,8 +510,8 @@ __xfs_getfsmap_rtdev(
        info->high.rm_blockcount = 0;
        xfs_getfsmap_set_irec_flags(&info->high, &keys[1]);
 
-       trace_xfs_fsmap_low_key(mp, info->dev, info->agno, &info->low);
-       trace_xfs_fsmap_high_key(mp, info->dev, info->agno, &info->high);
+       trace_xfs_fsmap_low_key(mp, info->dev, NULLAGNUMBER, &info->low);
+       trace_xfs_fsmap_high_key(mp, info->dev, NULLAGNUMBER, &info->high);
 
        return query_fn(tp, info);
 }
@@ -572,6 +574,7 @@ __xfs_getfsmap_datadev(
        void                            *priv)
 {
        struct xfs_mount                *mp = tp->t_mountp;
+       struct xfs_perag                *pag;
        struct xfs_btree_cur            *bt_cur = NULL;
        xfs_fsblock_t                   start_fsb;
        xfs_fsblock_t                   end_fsb;
@@ -610,20 +613,20 @@ __xfs_getfsmap_datadev(
        start_ag = XFS_FSB_TO_AGNO(mp, start_fsb);
        end_ag = XFS_FSB_TO_AGNO(mp, end_fsb);
 
-       /* Query each AG */
-       for (info->agno = start_ag; info->agno <= end_ag; info->agno++) {
+       for_each_perag_range(mp, start_ag, end_ag, pag) {
                /*
                 * Set the AG high key from the fsmap high key if this
                 * is the last AG that we're querying.
                 */
-               if (info->agno == end_ag) {
+               info->pag = pag;
+               if (pag->pag_agno == end_ag) {
                        info->high.rm_startblock = XFS_FSB_TO_AGBNO(mp,
                                        end_fsb);
                        info->high.rm_offset = XFS_BB_TO_FSBT(mp,
                                        keys[1].fmr_offset);
                        error = xfs_fsmap_owner_to_rmap(&info->high, &keys[1]);
                        if (error)
-                               goto err;
+                               break;
                        xfs_getfsmap_set_irec_flags(&info->high, &keys[1]);
                }
 
@@ -634,38 +637,45 @@ __xfs_getfsmap_datadev(
                        info->agf_bp = NULL;
                }
 
-               error = xfs_alloc_read_agf(mp, tp, info->agno, 0,
+               error = xfs_alloc_read_agf(mp, tp, pag->pag_agno, 0,
                                &info->agf_bp);
                if (error)
-                       goto err;
+                       break;
 
-               trace_xfs_fsmap_low_key(mp, info->dev, info->agno, &info->low);
-               trace_xfs_fsmap_high_key(mp, info->dev, info->agno,
+               trace_xfs_fsmap_low_key(mp, info->dev, pag->pag_agno,
+                               &info->low);
+               trace_xfs_fsmap_high_key(mp, info->dev, pag->pag_agno,
                                &info->high);
 
                error = query_fn(tp, info, &bt_cur, priv);
                if (error)
-                       goto err;
+                       break;
 
                /*
                 * Set the AG low key to the start of the AG prior to
                 * moving on to the next AG.
                 */
-               if (info->agno == start_ag) {
+               if (pag->pag_agno == start_ag) {
                        info->low.rm_startblock = 0;
                        info->low.rm_owner = 0;
                        info->low.rm_offset = 0;
                        info->low.rm_flags = 0;
                }
-       }
 
-       /* Report any gap at the end of the AG */
-       info->last = true;
-       error = query_fn(tp, info, &bt_cur, priv);
-       if (error)
-               goto err;
+               /*
+                * If this is the last AG, report any gap at the end of it
+                * before we drop the reference to the perag when the loop
+                * terminates.
+                */
+               if (pag->pag_agno == end_ag) {
+                       info->last = true;
+                       error = query_fn(tp, info, &bt_cur, priv);
+                       if (error)
+                               break;
+               }
+               info->pag = NULL;
+       }
 
-err:
        if (bt_cur)
                xfs_btree_del_cursor(bt_cur, error < 0 ? XFS_BTREE_ERROR :
                                                         XFS_BTREE_NOERROR);
@@ -673,6 +683,13 @@ err:
                xfs_trans_brelse(tp, info->agf_bp);
                info->agf_bp = NULL;
        }
+       if (info->pag) {
+               xfs_perag_put(info->pag);
+               info->pag = NULL;
+       } else if (pag) {
+               /* loop termination case */
+               xfs_perag_put(pag);
+       }
 
        return error;
 }
@@ -691,7 +708,7 @@ xfs_getfsmap_datadev_rmapbt_query(
 
        /* Allocate cursor for this AG and query_range it. */
        *curpp = xfs_rmapbt_init_cursor(tp->t_mountp, tp, info->agf_bp,
-                       info->agno);
+                       info->pag->pag_agno);
        return xfs_rmap_query_range(*curpp, &info->low, &info->high,
                        xfs_getfsmap_datadev_helper, info);
 }
@@ -724,7 +741,7 @@ xfs_getfsmap_datadev_bnobt_query(
 
        /* Allocate cursor for this AG and query_range it. */
        *curpp = xfs_allocbt_init_cursor(tp->t_mountp, tp, info->agf_bp,
-                       info->agno, XFS_BTNUM_BNO);
+                       info->pag->pag_agno, XFS_BTNUM_BNO);
        key->ar_startblock = info->low.rm_startblock;
        key[1].ar_startblock = info->high.rm_startblock;
        return xfs_alloc_query_range(*curpp, key, &key[1],
@@ -937,7 +954,7 @@ xfs_getfsmap(
 
                info.dev = handlers[i].dev;
                info.last = false;
-               info.agno = NULLAGNUMBER;
+               info.pag = NULL;
                error = handlers[i].fn(tp, dkeys, &info);
                if (error)
                        break;