[XFS] move xfs_bmbt_killroot to common code

xfs_bmbt_killroot is a mostly generic implementation of moving from a real
block based root to an inode based root. So move it to xfs_btree.c where
it can use all the nice infrastructure there and make it pointer size
agnostic

The new name for it is xfs_btree_kill_iroot, following the old naming but
making it clear we're dealing with the root in inode case here, and to
avoid confusion with xfs_btree_new_root which is used for the not inode
rooted case. I've also added a comment describing what it does and why
it's named the way it is.

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32203a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>

5 files changed, 185 insertions, 94 deletions

diff --git a/fs/xfs/xfs_alloc_btree.c b/fs/xfs/xfs_alloc_btree.c
index 818adca77fc6..f124ddd91c08 100644
--- a/fs/xfs/xfs_alloc_btree.c
+++ b/fs/xfs/xfs_alloc_btree.c
@@ -834,6 +834,37 @@ xfs_allocbt_alloc_block(
         return 0;
 }
 
+STATIC int
+xfs_allocbt_free_block(
+        struct xfs_btree_cur    *cur,
+        struct xfs_buf          *bp)
+{
+        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
+        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
+        xfs_agblock_t           bno;
+        int                     error;
+
+        bno = XFS_DADDR_TO_AGBNO(cur->bc_mp, XFS_BUF_ADDR(bp));
+        error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1);
+        if (error)
+                return error;
+
+        /*
+         * Since blocks move to the free list without the coordination used in
+         * xfs_bmap_finish, we can't allow block to be available for
+         * reallocation and non-transaction writing (user data) until we know
+         * that the transaction that moved it to the free list is permanently
+         * on disk. We track the blocks by declaring these blocks as "busy";
+         * the busy list is maintained on a per-ag basis and each transaction
+         * records which entries should be removed when the iclog commits to
+         * disk. If a busy block is allocated, the iclog is pushed up to the
+         * LSN that freed the block.
+         */
+        xfs_alloc_mark_busy(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1);
+        xfs_trans_agbtree_delta(cur->bc_tp, -1);
+        return 0;
+}
+
 /*
  * Update the longest extent in the AGF
  */
@@ -1025,6 +1056,7 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
         .dup_cursor             = xfs_allocbt_dup_cursor,
         .set_root               = xfs_allocbt_set_root,
         .alloc_block            = xfs_allocbt_alloc_block,
+        .free_block             = xfs_allocbt_free_block,
         .update_lastrec         = xfs_allocbt_update_lastrec,
         .get_maxrecs            = xfs_allocbt_get_maxrecs,
         .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
diff --git a/fs/xfs/xfs_bmap_btree.c b/fs/xfs/xfs_bmap_btree.c
index 2b15df32b7d2..6b7774ebc26a 100644
--- a/fs/xfs/xfs_bmap_btree.c
+++ b/fs/xfs/xfs_bmap_btree.c
@@ -49,7 +49,6 @@
  */
 
 
-STATIC int xfs_bmbt_killroot(xfs_btree_cur_t *);
 STATIC void xfs_bmbt_log_keys(xfs_btree_cur_t *, xfs_buf_t *, int, int);
 STATIC void xfs_bmbt_log_ptrs(xfs_btree_cur_t *, xfs_buf_t *, int, int);
 
@@ -194,7 +193,7 @@ xfs_bmbt_delrec(
         if (level == cur->bc_nlevels - 1) {
                 xfs_iroot_realloc(cur->bc_private.b.ip, -1,
                         cur->bc_private.b.whichfork);
-                if ((error = xfs_bmbt_killroot(cur))) {
+                if ((error = xfs_btree_kill_iroot(cur))) {
                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                         goto error0;
                 }
@@ -228,7 +227,7 @@ xfs_bmbt_delrec(
          */
         if (lbno == NULLFSBLOCK && rbno == NULLFSBLOCK &&
             level == cur->bc_nlevels - 2) {
-                if ((error = xfs_bmbt_killroot(cur))) {
+                if ((error = xfs_btree_kill_iroot(cur))) {
                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                         goto error0;
                 }
@@ -456,97 +455,6 @@ error0:
         return error;
 }
 
-STATIC int
-xfs_bmbt_killroot(
-        xfs_btree_cur_t         *cur)
-{
-        xfs_bmbt_block_t        *block;
-        xfs_bmbt_block_t        *cblock;
-        xfs_buf_t               *cbp;
-        xfs_bmbt_key_t          *ckp;
-        xfs_bmbt_ptr_t          *cpp;
-#ifdef DEBUG
-        int                     error;
-#endif
-        int                     i;
-        xfs_bmbt_key_t          *kp;
-        xfs_inode_t             *ip;
-        xfs_ifork_t             *ifp;
-        int                     level;
-        xfs_bmbt_ptr_t          *pp;
-
-        XFS_BMBT_TRACE_CURSOR(cur, ENTRY);
-        level = cur->bc_nlevels - 1;
-        ASSERT(level >= 1);
-        /*
-         * Don't deal with the root block needs to be a leaf case.
-         * We're just going to turn the thing back into extents anyway.
-         */
-        if (level == 1) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                return 0;
-        }
-        block = xfs_bmbt_get_block(cur, level, &cbp);
-        /*
-         * Give up if the root has multiple children.
-         */
-        if (be16_to_cpu(block->bb_numrecs) != 1) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                return 0;
-        }
-        /*
-         * Only do this if the next level will fit.
-         * Then the data must be copied up to the inode,
-         * instead of freeing the root you free the next level.
-         */
-        cbp = cur->bc_bufs[level - 1];
-        cblock = XFS_BUF_TO_BMBT_BLOCK(cbp);
-        if (be16_to_cpu(cblock->bb_numrecs) > XFS_BMAP_BLOCK_DMAXRECS(level, cur)) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                return 0;
-        }
-        ASSERT(be64_to_cpu(cblock->bb_leftsib) == NULLDFSBNO);
-        ASSERT(be64_to_cpu(cblock->bb_rightsib) == NULLDFSBNO);
-        ip = cur->bc_private.b.ip;
-        ifp = XFS_IFORK_PTR(ip, cur->bc_private.b.whichfork);
-        ASSERT(XFS_BMAP_BLOCK_IMAXRECS(level, cur) ==
-               XFS_BMAP_BROOT_MAXRECS(ifp->if_broot_bytes));
-        i = (int)(be16_to_cpu(cblock->bb_numrecs) - XFS_BMAP_BLOCK_IMAXRECS(level, cur));
-        if (i) {
-                xfs_iroot_realloc(ip, i, cur->bc_private.b.whichfork);
-                block = ifp->if_broot;
-        }
-        be16_add_cpu(&block->bb_numrecs, i);
-        ASSERT(block->bb_numrecs == cblock->bb_numrecs);
-        kp = XFS_BMAP_KEY_IADDR(block, 1, cur);
-        ckp = XFS_BMAP_KEY_IADDR(cblock, 1, cur);
-        memcpy(kp, ckp, be16_to_cpu(block->bb_numrecs) * sizeof(*kp));
-        pp = XFS_BMAP_PTR_IADDR(block, 1, cur);
-        cpp = XFS_BMAP_PTR_IADDR(cblock, 1, cur);
-#ifdef DEBUG
-        for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
-                if ((error = xfs_btree_check_lptr_disk(cur, cpp[i], level - 1))) {
-                        XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                        return error;
-                }
-        }
-#endif
-        memcpy(pp, cpp, be16_to_cpu(block->bb_numrecs) * sizeof(*pp));
-        xfs_bmap_add_free(XFS_DADDR_TO_FSB(cur->bc_mp, XFS_BUF_ADDR(cbp)), 1,
-                        cur->bc_private.b.flist, cur->bc_mp);
-        ip->i_d.di_nblocks--;
-        XFS_TRANS_MOD_DQUOT_BYINO(cur->bc_mp, cur->bc_tp, ip,
-                        XFS_TRANS_DQ_BCOUNT, -1L);
-        xfs_trans_binval(cur->bc_tp, cbp);
-        cur->bc_bufs[level - 1] = NULL;
-        be16_add_cpu(&block->bb_level, -1);
-        xfs_trans_log_inode(cur->bc_tp, ip,
-                XFS_ILOG_CORE | XFS_ILOG_FBROOT(cur->bc_private.b.whichfork));
-        cur->bc_nlevels--;
-        XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-        return 0;
-}
-
 /*
  * Log key values from the btree block.
  */
@@ -1299,6 +1207,25 @@ xfs_bmbt_alloc_block(
 }
 
 STATIC int
+xfs_bmbt_free_block(
+        struct xfs_btree_cur    *cur,
+        struct xfs_buf          *bp)
+{
+        struct xfs_mount        *mp = cur->bc_mp;
+        struct xfs_inode        *ip = cur->bc_private.b.ip;
+        struct xfs_trans        *tp = cur->bc_tp;
+        xfs_fsblock_t           fsbno = XFS_DADDR_TO_FSB(mp, XFS_BUF_ADDR(bp));
+
+        xfs_bmap_add_free(fsbno, 1, cur->bc_private.b.flist, mp);
+        ip->i_d.di_nblocks--;
+
+        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+        XFS_TRANS_MOD_DQUOT_BYINO(mp, tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
+        xfs_trans_binval(tp, bp);
+        return 0;
+}
+
+STATIC int
 xfs_bmbt_get_maxrecs(
         struct xfs_btree_cur    *cur,
         int                     level)
@@ -1460,6 +1387,7 @@ static const struct xfs_btree_ops xfs_bmbt_ops = {
         .dup_cursor             = xfs_bmbt_dup_cursor,
         .update_cursor          = xfs_bmbt_update_cursor,
         .alloc_block            = xfs_bmbt_alloc_block,
+        .free_block             = xfs_bmbt_free_block,
         .get_maxrecs            = xfs_bmbt_get_maxrecs,
         .get_dmaxrecs           = xfs_bmbt_get_dmaxrecs,
         .init_key_from_rec      = xfs_bmbt_init_key_from_rec,
diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c
index 36477aae77df..75a8a7b00dfb 100644
--- a/fs/xfs/xfs_btree.c
+++ b/fs/xfs/xfs_btree.c
@@ -3059,3 +3059,115 @@ error0:
         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
         return error;
 }
+
+/*
+ * Try to merge a non-leaf block back into the inode root.
+ *
+ * Note: the killroot names comes from the fact that we're effectively
+ * killing the old root block.  But because we can't just delete the
+ * inode we have to copy the single block it was pointing to into the
+ * inode.
+ */
+int
+xfs_btree_kill_iroot(
+        struct xfs_btree_cur    *cur)
+{
+        int                     whichfork = cur->bc_private.b.whichfork;
+        struct xfs_inode        *ip = cur->bc_private.b.ip;
+        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
+        struct xfs_btree_block  *block;
+        struct xfs_btree_block  *cblock;
+        union xfs_btree_key     *kp;
+        union xfs_btree_key     *ckp;
+        union xfs_btree_ptr     *pp;
+        union xfs_btree_ptr     *cpp;
+        struct xfs_buf          *cbp;
+        int                     level;
+        int                     index;
+        int                     numrecs;
+#ifdef DEBUG
+        union xfs_btree_ptr     ptr;
+        int                     i;
+#endif
+
+        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
+
+        ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
+        ASSERT(cur->bc_nlevels > 1);
+
+        /*
+         * Don't deal with the root block needs to be a leaf case.
+         * We're just going to turn the thing back into extents anyway.
+         */
+        level = cur->bc_nlevels - 1;
+        if (level == 1)
+                goto out0;
+
+        /*
+         * Give up if the root has multiple children.
+         */
+        block = xfs_btree_get_iroot(cur);
+        if (xfs_btree_get_numrecs(block) != 1)
+                goto out0;
+
+        cblock = xfs_btree_get_block(cur, level - 1, &cbp);
+        numrecs = xfs_btree_get_numrecs(cblock);
+
+        /*
+         * Only do this if the next level will fit.
+         * Then the data must be copied up to the inode,
+         * instead of freeing the root you free the next level.
+         */
+        if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
+                goto out0;
+
+        XFS_BTREE_STATS_INC(cur, killroot);
+
+#ifdef DEBUG
+        xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
+        ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
+        xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
+        ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
+#endif
+
+        index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
+        if (index) {
+                xfs_iroot_realloc(cur->bc_private.b.ip, index,
+                                  cur->bc_private.b.whichfork);
+                block = (struct xfs_btree_block *)ifp->if_broot;
+        }
+
+        be16_add_cpu(&block->bb_numrecs, index);
+        ASSERT(block->bb_numrecs == cblock->bb_numrecs);
+
+        kp = xfs_btree_key_addr(cur, 1, block);
+        ckp = xfs_btree_key_addr(cur, 1, cblock);
+        xfs_btree_copy_keys(cur, kp, ckp, numrecs);
+
+        pp = xfs_btree_ptr_addr(cur, 1, block);
+        cpp = xfs_btree_ptr_addr(cur, 1, cblock);
+#ifdef DEBUG
+        for (i = 0; i < numrecs; i++) {
+                int             error;
+
+                error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
+                if (error) {
+                        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
+                        return error;
+                }
+        }
+#endif
+        xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
+
+        cur->bc_ops->free_block(cur, cbp);
+        XFS_BTREE_STATS_INC(cur, free);
+
+        cur->bc_bufs[level - 1] = NULL;
+        be16_add_cpu(&block->bb_level, -1);
+        xfs_trans_log_inode(cur->bc_tp, ip,
+                XFS_ILOG_CORE | XFS_ILOG_FBROOT(cur->bc_private.b.whichfork));
+        cur->bc_nlevels--;
+out0:
+        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+        return 0;
+}
diff --git a/fs/xfs/xfs_btree.h b/fs/xfs/xfs_btree.h
index 6f03871f5995..ff2552febba7 100644
--- a/fs/xfs/xfs_btree.h
+++ b/fs/xfs/xfs_btree.h
@@ -198,6 +198,7 @@ struct xfs_btree_ops {
                                union xfs_btree_ptr *start_bno,
                                union xfs_btree_ptr *new_bno,
                                int length, int *stat);
+        int     (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
 
         /* update last record information */
         void    (*update_lastrec)(struct xfs_btree_cur *cur,
@@ -559,6 +560,7 @@ int xfs_btree_split(struct xfs_btree_cur *, int, union xfs_btree_ptr *,
                 union xfs_btree_key *, struct xfs_btree_cur **, int *);
 int xfs_btree_new_root(struct xfs_btree_cur *, int *);
 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
+int xfs_btree_kill_iroot(struct xfs_btree_cur *);
 int xfs_btree_insert(struct xfs_btree_cur *, int *);
 
 /*
diff --git a/fs/xfs/xfs_ialloc_btree.c b/fs/xfs/xfs_ialloc_btree.c
index 8f66e2720566..90f1d4ee7720 100644
--- a/fs/xfs/xfs_ialloc_btree.c
+++ b/fs/xfs/xfs_ialloc_btree.c
@@ -754,6 +754,22 @@ xfs_inobt_alloc_block(
         return 0;
 }
 
+STATIC int
+xfs_inobt_free_block(
+        struct xfs_btree_cur    *cur,
+        struct xfs_buf          *bp)
+{
+        xfs_fsblock_t           fsbno;
+        int                     error;
+
+        fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, XFS_BUF_ADDR(bp));
+        error = xfs_free_extent(cur->bc_tp, fsbno, 1);
+        if (error)
+                return error;
+
+        xfs_trans_binval(cur->bc_tp, bp);
+        return error;
+}
 
 STATIC int
 xfs_inobt_get_maxrecs(
@@ -886,6 +902,7 @@ static const struct xfs_btree_ops xfs_inobt_ops = {
         .dup_cursor             = xfs_inobt_dup_cursor,
         .set_root               = xfs_inobt_set_root,
         .alloc_block            = xfs_inobt_alloc_block,
+        .free_block             = xfs_inobt_free_block,
         .get_maxrecs            = xfs_inobt_get_maxrecs,
         .init_key_from_rec      = xfs_inobt_init_key_from_rec,
         .init_rec_from_key      = xfs_inobt_init_rec_from_key,