[PATCH 05/14] xfs: repair the rmapbt

Darrick J. Wong
2018-05-30T19:31:15Z

From: Darrick J. Wong <darrick.wong@oracle.com>

Rebuild the reverse mapping btree from all primary metadata.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/Makefile | 1
fs/xfs/scrub/common.c | 6
fs/xfs/scrub/repair.c | 119 +++++++
fs/xfs/scrub/repair.h | 27 +
fs/xfs/scrub/rmap.c | 6
fs/xfs/scrub/rmap_repair.c | 796 ++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/scrub.c | 18 +
fs/xfs/scrub/scrub.h | 2
fs/xfs/xfs_mount.h | 1
fs/xfs/xfs_super.c | 27 +
fs/xfs/xfs_trans.c | 7
11 files changed, 1004 insertions(+), 6 deletions(-)
create mode 100644 fs/xfs/scrub/rmap_repair.c

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 7c442f83b179..b9bbac3d5075 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -178,6 +178,7 @@ xfs-y += $(addprefix scrub/, \
alloc_repair.o \
ialloc_repair.o \
repair.o \
+ rmap_repair.o \
)
endif
endif
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index 89938b328954..f92994716522 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -603,9 +603,13 @@ xfs_scrub_trans_alloc(
struct xfs_scrub_context *sc,
uint resblks)
{
+ uint flags = 0;
+
+ if (sc->fs_frozen)
+ flags |= XFS_TRANS_NO_WRITECOUNT;
if (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR)
return xfs_trans_alloc(sc->mp, &M_RES(sc->mp)->tr_itruncate,
- resblks, 0, 0, &sc->tp);
+ resblks, 0, flags, &sc->tp);

return xfs_trans_alloc_empty(sc->mp, &sc->tp);
}
diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index 45a91841c0ac..4b5d599d53b9 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -43,6 +43,8 @@
#include "xfs_ag_resv.h"
#include "xfs_trans_space.h"
#include "xfs_quota.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_util.h"
#include "scrub/xfs_scrub.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
@@ -1146,3 +1148,120 @@ xfs_repair_mod_ino_counts(
(int64_t)freecount - old_freecount);
}
}
+
+/*
+ * Freeze the FS against all other activity so that we can avoid ABBA
+ * deadlocks while taking locks in unusual orders so that we can rebuild
+ * metadata structures such as the rmapbt.
+ */
+int
+xfs_repair_fs_freeze(
+ struct xfs_scrub_context *sc)
+{
+ int error;
+
+ error = freeze_super(sc->mp->m_super);
+ if (error)
+ return error;
+ sc->fs_frozen = true;
+ return 0;
+}
+
+/* Unfreeze the FS. */
+int
+xfs_repair_fs_thaw(
+ struct xfs_scrub_context *sc)
+{
+ struct inode *inode, *o;
+ int error;
+
+ sc->fs_frozen = false;
+ error = thaw_super(sc->mp->m_super);
+
+ inode = sc->frozen_inode_list;
+ while (inode) {
+ o = inode->i_private;
+ inode->i_private = NULL;
+ iput(inode);
+ inode = o;
+ }
+
+ return error;
+}
+
+/*
+ * Release an inode while the fs is frozen for a repair.
+ *
+ * We froze the fs so that everything in the fs will be static except for the
+ * metadata that we are rebuilding. Users can't modify things and periodic
+ * block reclaim is stopped, which leaves only the reclamation that happens
+ * as part of evicting an inode from memory. We can't have that either, so
+ * redirect those inodes onto a side list and free them once we've thawed the
+ * fs. Note that memory reclaim is allowed to get to the other inodes.
+ */
+void
+xfs_repair_frozen_iput(
+ struct xfs_scrub_context *sc,
+ struct xfs_inode *ip)
+{
+ struct xfs_bmbt_irec imap;
+ xfs_fileoff_t end_fsb;
+ xfs_fileoff_t last_fsb;
+ xfs_filblks_t map_len;
+ int nimaps;
+ int error;
+
+ if (!xfs_can_free_eofblocks(ip, true))
+ goto iput;
+
+ /*
+ * Figure out if there are any blocks beyond the end of the file.
+ * If not, then free immediately.
+ */
+ end_fsb = XFS_B_TO_FSB(sc->mp, (xfs_ufsize_t)XFS_ISIZE(ip));
+ last_fsb = XFS_B_TO_FSB(sc->mp, sc->mp->m_super->s_maxbytes);
+ if (last_fsb <= end_fsb)
+ goto iput;
+ map_len = last_fsb - end_fsb;
+
+ nimaps = 1;
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+ error = xfs_bmapi_read(ip, end_fsb, map_len, &imap, &nimaps, 0);
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+
+ /*
+ * If there are blocks after the end of file, hang on to them so that
+ * they don't get destroyed while we aren't able to handle any fs
+ * modifications.
+ */
+ if (!error && (nimaps != 0) &&
+ (imap.br_startblock != HOLESTARTBLOCK ||
+ ip->i_delayed_blks)) {
+ VFS_I(ip)->i_private = sc->frozen_inode_list;
+ sc->frozen_inode_list = VFS_I(ip);
+ return;
+ }
+iput:
+ iput(VFS_I(ip));
+}
+
+/* Read all AG headers and attach to this transaction. */
+int
+xfs_repair_grab_all_ag_headers(
+ struct xfs_scrub_context *sc)
+{
+ struct xfs_mount *mp = sc->mp;
+ struct xfs_buf *agi;
+ struct xfs_buf *agf;
+ struct xfs_buf *agfl;
+ xfs_agnumber_t agno;
+ int error = 0;
+
+ for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
+ error = xfs_scrub_ag_read_headers(sc, agno, &agi, &agf, &agfl);
+ if (error)
+ break;
+ }
+
+ return error;
+}
diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
index eaacbd589754..a3ee8d1035c0 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -103,6 +103,11 @@ int xfs_repair_mod_fdblocks(struct xfs_scrub_context *sc,
void xfs_repair_mod_ino_counts(struct xfs_scrub_context *sc,
xfs_agino_t old_count, xfs_agino_t count,
xfs_agino_t old_freecount, xfs_agino_t freecount);
+int xfs_repair_fs_freeze(struct xfs_scrub_context *sc);
+int xfs_repair_fs_thaw(struct xfs_scrub_context *sc);
+void xfs_repair_frozen_iput(struct xfs_scrub_context *sc, struct xfs_inode *ip);
+int xfs_repair_grab_all_ag_headers(struct xfs_scrub_context *sc);
+int xfs_repair_rmapbt_setup(struct xfs_scrub_context *sc, struct xfs_inode *ip);

/* Metadata repairers */

@@ -113,6 +118,7 @@ int xfs_repair_agfl(struct xfs_scrub_context *sc);
int xfs_repair_agi(struct xfs_scrub_context *sc);
int xfs_repair_allocbt(struct xfs_scrub_context *sc);
int xfs_repair_iallocbt(struct xfs_scrub_context *sc);
+int xfs_repair_rmapbt(struct xfs_scrub_context *sc);

#else

@@ -134,6 +140,26 @@ xfs_repair_calc_ag_resblks(
return 0;
}

+static inline int xfs_repair_fs_freeze(struct xfs_scrub_context *sc)
+{
+ ASSERT(0);
+ return -EOPNOTSUPP;
+}
+
+static inline int xfs_repair_fs_thaw(struct xfs_scrub_context *sc)
+{
+ ASSERT(0);
+ return -EIO;
+}
+
+static inline int xfs_repair_rmapbt_setup(
+ struct xfs_scrub_context *sc,
+ struct xfs_inode *ip)
+{
+ /* We don't support rmap repair, but we can still do a scan. */
+ return xfs_scrub_setup_ag_btree(sc, ip, false);
+}
+
#define xfs_repair_probe xfs_repair_notsupported
#define xfs_repair_superblock xfs_repair_notsupported
#define xfs_repair_agf xfs_repair_notsupported
@@ -141,6 +167,7 @@ xfs_repair_calc_ag_resblks(
#define xfs_repair_agi xfs_repair_notsupported
#define xfs_repair_allocbt xfs_repair_notsupported
#define xfs_repair_iallocbt xfs_repair_notsupported
+#define xfs_repair_rmapbt xfs_repair_notsupported

#endif /* CONFIG_XFS_ONLINE_REPAIR */

diff --git a/fs/xfs/scrub/rmap.c b/fs/xfs/scrub/rmap.c
index b376a9a77c04..14d9b7b40f7b 100644
--- a/fs/xfs/scrub/rmap.c
+++ b/fs/xfs/scrub/rmap.c
@@ -38,6 +38,7 @@
#include "scrub/common.h"
#include "scrub/btree.h"
#include "scrub/trace.h"
+#include "scrub/repair.h"

/*
* Set us up to scrub reverse mapping btrees.
@@ -47,7 +48,10 @@ xfs_scrub_setup_ag_rmapbt(
struct xfs_scrub_context *sc,
struct xfs_inode *ip)
{
- return xfs_scrub_setup_ag_btree(sc, ip, false);
+ if (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR)
+ return xfs_repair_rmapbt_setup(sc, ip);
+ else
+ return xfs_scrub_setup_ag_btree(sc, ip, false);
}

/* Reverse-mapping scrubber. */
diff --git a/fs/xfs/scrub/rmap_repair.c b/fs/xfs/scrub/rmap_repair.c
new file mode 100644
index 000000000000..6d2883f11c49
--- /dev/null
+++ b/fs/xfs/scrub/rmap_repair.c
@@ -0,0 +1,796 @@
+/*
+ * Copyright (C) 2018 Oracle. All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_alloc.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_ialloc.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_refcount.h"
+#include "xfs_refcount_btree.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/trace.h"
+#include "scrub/repair.h"
+
+/* Reverse-mapping repair. */
+
+/* Set us up to repair reverse mapping btrees. */
+int
+xfs_repair_rmapbt_setup(
+ struct xfs_scrub_context *sc,
+ struct xfs_inode *ip)
+{
+ int error;
+
+ /*
+ * Freeze out anything that can lock an inode. We reconstruct
+ * the rmapbt by reading inode bmaps with the AGF held, which is
+ * only safe w.r.t. ABBA deadlocks if we're the only ones locking
+ * inodes.
+ */
+ error = xfs_repair_fs_freeze(sc);
+ if (error)
+ return error;
+
+ /* Check the AG number and set up the scrub context. */
+ error = xfs_scrub_setup_fs(sc, ip);
+ if (error)
+ return error;
+
+ /*
+ * Lock all the AG header buffers so that we can read all the
+ * per-AG metadata too.
+ */
+ error = xfs_repair_grab_all_ag_headers(sc);
+ if (error)
+ return error;
+
+ return xfs_scrub_ag_init(sc, sc->sm->sm_agno, &sc->sa);
+}
+
+struct xfs_repair_rmapbt_extent {
+ struct list_head list;
+ struct xfs_rmap_irec rmap;
+};
+
+struct xfs_repair_rmapbt {
+ struct list_head rmaplist;
+ struct xfs_repair_extent_list rmap_freelist;
+ struct xfs_repair_extent_list bno_freelist;
+ struct xfs_scrub_context *sc;
+ uint64_t owner;
+ xfs_extlen_t btblocks;
+ xfs_agblock_t next_bno;
+ uint64_t nr_records;
+};
+
+/* Initialize an rmap. */
+static inline int
+xfs_repair_rmapbt_new_rmap(
+ struct xfs_repair_rmapbt *rr,
+ xfs_agblock_t startblock,
+ xfs_extlen_t blockcount,
+ uint64_t owner,
+ uint64_t offset,
+ unsigned int flags)
+{
+ struct xfs_repair_rmapbt_extent *rre;
+ int error = 0;
+
+ trace_xfs_repair_rmap_extent_fn(rr->sc->mp, rr->sc->sa.agno,
+ startblock, blockcount, owner, offset, flags);
+
+ if (xfs_scrub_should_terminate(rr->sc, &error))
+ return error;
+
+ rre = kmem_alloc(sizeof(struct xfs_repair_rmapbt_extent), KM_MAYFAIL);
+ if (!rre)
+ return -ENOMEM;
+ INIT_LIST_HEAD(&rre->list);
+ rre->rmap.rm_startblock = startblock;
+ rre->rmap.rm_blockcount = blockcount;
+ rre->rmap.rm_owner = owner;
+ rre->rmap.rm_offset = offset;
+ rre->rmap.rm_flags = flags;
+ list_add_tail(&rre->list, &rr->rmaplist);
+ rr->nr_records++;
+
+ return 0;
+}
+
+/* Add an AGFL block to the rmap list. */
+STATIC int
+xfs_repair_rmapbt_walk_agfl(
+ struct xfs_mount *mp,
+ xfs_agblock_t bno,
+ void *priv)
+{
+ struct xfs_repair_rmapbt *rr = priv;
+
+ return xfs_repair_rmapbt_new_rmap(rr, bno, 1, XFS_RMAP_OWN_AG, 0, 0);
+}
+
+/* Add a btree block to the rmap list. */
+STATIC int
+xfs_repair_rmapbt_visit_btblock(
+ struct xfs_btree_cur *cur,
+ int level,
+ void *priv)
+{
+ struct xfs_repair_rmapbt *rr = priv;
+ struct xfs_buf *bp;
+ xfs_fsblock_t fsb;
+
+ xfs_btree_get_block(cur, level, &bp);
+ if (!bp)
+ return 0;
+
+ rr->btblocks++;
+ fsb = XFS_DADDR_TO_FSB(cur->bc_mp, bp->b_bn);
+ return xfs_repair_rmapbt_new_rmap(rr, XFS_FSB_TO_AGBNO(cur->bc_mp, fsb),
+ 1, rr->owner, 0, 0);
+}
+
+/* Record inode btree rmaps. */
+STATIC int
+xfs_repair_rmapbt_inodes(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_rec *rec,
+ void *priv)
+{
+ struct xfs_inobt_rec_incore irec;
+ struct xfs_repair_rmapbt *rr = priv;
+ struct xfs_mount *mp = cur->bc_mp;
+ struct xfs_buf *bp;
+ xfs_fsblock_t fsb;
+ xfs_agino_t agino;
+ xfs_agino_t iperhole;
+ unsigned int i;
+ int error;
+
+ /* Record the inobt blocks */
+ for (i = 0; i < cur->bc_nlevels && cur->bc_ptrs[i] == 1; i++) {
+ xfs_btree_get_block(cur, i, &bp);
+ if (!bp)
+ continue;
+ fsb = XFS_DADDR_TO_FSB(mp, bp->b_bn);
+ error = xfs_repair_rmapbt_new_rmap(rr,
+ XFS_FSB_TO_AGBNO(mp, fsb), 1,
+ XFS_RMAP_OWN_INOBT, 0, 0);
+ if (error)
+ return error;
+ }
+
+ xfs_inobt_btrec_to_irec(mp, rec, &irec);
+
+ /* Record a non-sparse inode chunk. */
+ if (irec.ir_holemask == XFS_INOBT_HOLEMASK_FULL)
+ return xfs_repair_rmapbt_new_rmap(rr,
+ XFS_AGINO_TO_AGBNO(mp, irec.ir_startino),
+ XFS_INODES_PER_CHUNK / mp->m_sb.sb_inopblock,
+ XFS_RMAP_OWN_INODES, 0, 0);
+
+ /* Iterate each chunk. */
+ iperhole = max_t(xfs_agino_t, mp->m_sb.sb_inopblock,
+ XFS_INODES_PER_HOLEMASK_BIT);
+ for (i = 0, agino = irec.ir_startino;
+ i < XFS_INOBT_HOLEMASK_BITS;
+ i += iperhole / XFS_INODES_PER_HOLEMASK_BIT, agino += iperhole) {
+ /* Skip holes. */
+ if (irec.ir_holemask & (1 << i))
+ continue;
+
+ /* Record the inode chunk otherwise. */
+ error = xfs_repair_rmapbt_new_rmap(rr,
+ XFS_AGINO_TO_AGBNO(mp, agino),
+ iperhole / mp->m_sb.sb_inopblock,
+ XFS_RMAP_OWN_INODES, 0, 0);
+ if (error)
+ return error;
+ }
+
+ return 0;
+}
+
+/* Record a CoW staging extent. */
+STATIC int
+xfs_repair_rmapbt_refcount(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_rec *rec,
+ void *priv)
+{
+ struct xfs_repair_rmapbt *rr = priv;
+ struct xfs_refcount_irec refc;
+
+ xfs_refcount_btrec_to_irec(rec, &refc);
+ if (refc.rc_refcount != 1)
+ return -EFSCORRUPTED;
+
+ return xfs_repair_rmapbt_new_rmap(rr,
+ refc.rc_startblock - XFS_REFC_COW_START,
+ refc.rc_blockcount, XFS_RMAP_OWN_COW, 0, 0);
+}
+
+/* Add a bmbt block to the rmap list. */
+STATIC int
+xfs_repair_rmapbt_visit_bmbt(
+ struct xfs_btree_cur *cur,
+ int level,
+ void *priv)
+{
+ struct xfs_repair_rmapbt *rr = priv;
+ struct xfs_buf *bp;
+ xfs_fsblock_t fsb;
+ unsigned int flags = XFS_RMAP_BMBT_BLOCK;
+
+ xfs_btree_get_block(cur, level, &bp);
+ if (!bp)
+ return 0;
+
+ fsb = XFS_DADDR_TO_FSB(cur->bc_mp, bp->b_bn);
+ if (XFS_FSB_TO_AGNO(cur->bc_mp, fsb) != rr->sc->sa.agno)
+ return 0;
+
+ if (cur->bc_private.b.whichfork == XFS_ATTR_FORK)
+ flags |= XFS_RMAP_ATTR_FORK;
+ return xfs_repair_rmapbt_new_rmap(rr,
+ XFS_FSB_TO_AGBNO(cur->bc_mp, fsb), 1,
+ cur->bc_private.b.ip->i_ino, 0, flags);
+}
+
+/* Determine rmap flags from fork and bmbt state. */
+static inline unsigned int
+xfs_repair_rmapbt_bmap_flags(
+ int whichfork,
+ xfs_exntst_t state)
+{
+ return (whichfork == XFS_ATTR_FORK ? XFS_RMAP_ATTR_FORK : 0) |
+ (state == XFS_EXT_UNWRITTEN ? XFS_RMAP_UNWRITTEN : 0);
+}
+
+/* Find all the extents from a given AG in an inode fork. */
+STATIC int
+xfs_repair_rmapbt_scan_ifork(
+ struct xfs_repair_rmapbt *rr,
+ struct xfs_inode *ip,
+ int whichfork)
+{
+ struct xfs_bmbt_irec rec;
+ struct xfs_iext_cursor icur;
+ struct xfs_mount *mp = rr->sc->mp;
+ struct xfs_btree_cur *cur = NULL;
+ struct xfs_ifork *ifp;
+ unsigned int rflags;
+ int fmt;
+ int error = 0;
+
+ /* Do we even have data mapping extents? */
+ fmt = XFS_IFORK_FORMAT(ip, whichfork);
+ ifp = XFS_IFORK_PTR(ip, whichfork);
+ switch (fmt) {
+ case XFS_DINODE_FMT_BTREE:
+ if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+ error = xfs_iread_extents(rr->sc->tp, ip, whichfork);
+ if (error)
+ return error;
+ }
+ break;
+ case XFS_DINODE_FMT_EXTENTS:
+ break;
+ default:
+ return 0;
+ }
+ if (!ifp)
+ return 0;
+
+ /* Find all the BMBT blocks in the AG. */
+ if (fmt == XFS_DINODE_FMT_BTREE) {
+ cur = xfs_bmbt_init_cursor(mp, rr->sc->tp, ip, whichfork);
+ error = xfs_btree_visit_blocks(cur,
+ xfs_repair_rmapbt_visit_bmbt, rr);
+ if (error)
+ goto out;
+ xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+ cur = NULL;
+ }
+
+ /* We're done if this is an rt inode's data fork. */
+ if (whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip))
+ return 0;
+
+ /* Find all the extents in the AG. */
+ for_each_xfs_iext(ifp, &icur, &rec) {
+ if (isnullstartblock(rec.br_startblock))
+ continue;
+ /* Stash non-hole extent. */
+ if (XFS_FSB_TO_AGNO(mp, rec.br_startblock) == rr->sc->sa.agno) {
+ rflags = xfs_repair_rmapbt_bmap_flags(whichfork,
+ rec.br_state);
+ error = xfs_repair_rmapbt_new_rmap(rr,
+ XFS_FSB_TO_AGBNO(mp, rec.br_startblock),
+ rec.br_blockcount, ip->i_ino,
+ rec.br_startoff, rflags);
+ if (error)
+ goto out;
+ }
+ }
+out:
+ if (cur)
+ xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+ return error;
+}
+
+/* Iterate all the inodes in an AG group. */
+STATIC int
+xfs_repair_rmapbt_scan_inobt(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_rec *rec,
+ void *priv)
+{
+ struct xfs_inobt_rec_incore irec;
+ struct xfs_repair_rmapbt *rr = priv;
+ struct xfs_mount *mp = cur->bc_mp;
+ struct xfs_inode *ip = NULL;
+ xfs_ino_t ino;
+ xfs_agino_t agino;
+ int chunkidx;
+ int lock_mode = 0;
+ int error = 0;
+
+ xfs_inobt_btrec_to_irec(mp, rec, &irec);
+
+ for (chunkidx = 0, agino = irec.ir_startino;
+ chunkidx < XFS_INODES_PER_CHUNK;
+ chunkidx++, agino++) {
+ bool inuse;
+
+ /* Skip if this inode is free */
+ if (XFS_INOBT_MASK(chunkidx) & irec.ir_free)
+ continue;
+ ino = XFS_AGINO_TO_INO(mp, cur->bc_private.a.agno, agino);
+
+ /* Back off and try again if an inode is being reclaimed */
+ error = xfs_icache_inode_is_allocated(mp, cur->bc_tp, ino,
+ &inuse);
+ if (error == -EAGAIN)
+ return -EDEADLOCK;
+
+ /*
+ * Grab inode for scanning. We cannot use DONTCACHE here
+ * because we already have a transaction so the iput must not
+ * trigger inode reclaim (which might allocate a transaction
+ * to clean up posteof blocks).
+ */
+ error = xfs_iget(mp, cur->bc_tp, ino, 0, 0, &ip);
+ if (error)
+ return error;
+
+ if ((ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
+ !(ip->i_df.if_flags & XFS_IFEXTENTS)) ||
+ (ip->i_d.di_aformat == XFS_DINODE_FMT_BTREE &&
+ !(ip->i_afp->if_flags & XFS_IFEXTENTS)))
+ lock_mode = XFS_ILOCK_EXCL;
+ else
+ lock_mode = XFS_ILOCK_SHARED;
+ if (!xfs_ilock_nowait(ip, lock_mode)) {
+ error = -EBUSY;
+ goto out_rele;
+ }
+
+ /* Check the data fork. */
+ error = xfs_repair_rmapbt_scan_ifork(rr, ip, XFS_DATA_FORK);
+ if (error)
+ goto out_unlock;
+
+ /* Check the attr fork. */
+ error = xfs_repair_rmapbt_scan_ifork(rr, ip, XFS_ATTR_FORK);
+ if (error)
+ goto out_unlock;
+
+ xfs_iunlock(ip, lock_mode);
+ xfs_repair_frozen_iput(rr->sc, ip);
+ ip = NULL;
+ }
+
+ return error;
+out_unlock:
+ xfs_iunlock(ip, lock_mode);
+out_rele:
+ iput(VFS_I(ip));
+ return error;
+}
+
+/* Record extents that aren't in use from gaps in the rmap records. */
+STATIC int
+xfs_repair_rmapbt_record_rmap_freesp(
+ struct xfs_btree_cur *cur,
+ struct xfs_rmap_irec *rec,
+ void *priv)
+{
+ struct xfs_repair_rmapbt *rr = priv;
+ xfs_fsblock_t fsb;
+ int error;
+
+ /* Record the free space we find. */
+ if (rec->rm_startblock > rr->next_bno) {
+ fsb = XFS_AGB_TO_FSB(cur->bc_mp, cur->bc_private.a.agno,
+ rr->next_bno);
+ error = xfs_repair_collect_btree_extent(rr->sc,
+ &rr->rmap_freelist, fsb,
+ rec->rm_startblock - rr->next_bno);
+ if (error)
+ return error;
+ }
+ rr->next_bno = max_t(xfs_agblock_t, rr->next_bno,
+ rec->rm_startblock + rec->rm_blockcount);
+ return 0;
+}
+
+/* Record extents that aren't in use from the bnobt records. */
+STATIC int
+xfs_repair_rmapbt_record_bno_freesp(
+ struct xfs_btree_cur *cur,
+ struct xfs_alloc_rec_incore *rec,
+ void *priv)
+{
+ struct xfs_repair_rmapbt *rr = priv;
+ xfs_fsblock_t fsb;
+
+ /* Record the free space we find. */
+ fsb = XFS_AGB_TO_FSB(cur->bc_mp, cur->bc_private.a.agno,
+ rec->ar_startblock);
+ return xfs_repair_collect_btree_extent(rr->sc, &rr->bno_freelist,
+ fsb, rec->ar_blockcount);
+}
+
+/* Compare two rmapbt extents. */
+static int
+xfs_repair_rmapbt_extent_cmp(
+ void *priv,
+ struct list_head *a,
+ struct list_head *b)
+{
+ struct xfs_repair_rmapbt_extent *ap;
+ struct xfs_repair_rmapbt_extent *bp;
+
+ ap = container_of(a, struct xfs_repair_rmapbt_extent, list);
+ bp = container_of(b, struct xfs_repair_rmapbt_extent, list);
+ return xfs_rmap_compare(&ap->rmap, &bp->rmap);
+}
+
+#define RMAP(type, startblock, blockcount) xfs_repair_rmapbt_new_rmap( \
+ &rr, (startblock), (blockcount), \
+ XFS_RMAP_OWN_##type, 0, 0)
+/* Repair the rmap btree for some AG. */
+int
+xfs_repair_rmapbt(
+ struct xfs_scrub_context *sc)
+{
+ struct xfs_repair_rmapbt rr;
+ struct xfs_owner_info oinfo;
+ struct xfs_repair_rmapbt_extent *rre;
+ struct xfs_repair_rmapbt_extent *n;
+ struct xfs_mount *mp = sc->mp;
+ struct xfs_btree_cur *cur = NULL;
+ struct xfs_buf *bp = NULL;
+ struct xfs_agf *agf;
+ struct xfs_agi *agi;
+ struct xfs_perag *pag;
+ xfs_fsblock_t btfsb;
+ xfs_agnumber_t ag;
+ xfs_agblock_t agend;
+ xfs_extlen_t freesp_btblocks;
+ int error;
+
+ xfs_scrub_perag_get(sc->mp, &sc->sa);
+ pag = sc->sa.pag;
+ INIT_LIST_HEAD(&rr.rmaplist);
+ xfs_repair_init_extent_list(&rr.rmap_freelist);
+ xfs_repair_init_extent_list(&rr.bno_freelist);
+ rr.sc = sc;
+ rr.nr_records = 0;
+
+ /* Collect rmaps for all AG headers. */
+ error = RMAP(FS, XFS_SB_BLOCK(mp), 1);
+ if (error)
+ goto out;
+ rre = list_last_entry(&rr.rmaplist, struct xfs_repair_rmapbt_extent,
+ list);
+
+ if (rre->rmap.rm_startblock != XFS_AGF_BLOCK(mp)) {
+ error = RMAP(FS, XFS_AGF_BLOCK(mp), 1);
+ if (error)
+ goto out;
+ rre = list_last_entry(&rr.rmaplist,
+ struct xfs_repair_rmapbt_extent, list);
+ }
+
+ if (rre->rmap.rm_startblock != XFS_AGI_BLOCK(mp)) {
+ error = RMAP(FS, XFS_AGI_BLOCK(mp), 1);
+ if (error)
+ goto out;
+ rre = list_last_entry(&rr.rmaplist,
+ struct xfs_repair_rmapbt_extent, list);
+ }
+
+ if (rre->rmap.rm_startblock != XFS_AGFL_BLOCK(mp)) {
+ error = RMAP(FS, XFS_AGFL_BLOCK(mp), 1);
+ if (error)
+ goto out;
+ }
+
+ error = xfs_agfl_walk(sc->mp, XFS_BUF_TO_AGF(sc->sa.agf_bp),
+ sc->sa.agfl_bp, xfs_repair_rmapbt_walk_agfl, &rr);
+ if (error)
+ goto out;
+
+ /* Collect rmap for the log if it's in this AG. */
+ if (mp->m_sb.sb_logstart &&
+ XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == sc->sa.agno) {
+ error = RMAP(LOG, XFS_FSB_TO_AGBNO(mp, mp->m_sb.sb_logstart),
+ mp->m_sb.sb_logblocks);
+ if (error)
+ goto out;
+ }
+
+ /* Collect rmaps for the free space btrees. */
+ rr.owner = XFS_RMAP_OWN_AG;
+ rr.btblocks = 0;
+ cur = xfs_allocbt_init_cursor(mp, sc->tp, sc->sa.agf_bp, sc->sa.agno,
+ XFS_BTNUM_BNO);
+ error = xfs_btree_visit_blocks(cur, xfs_repair_rmapbt_visit_btblock,
+ &rr);
+ if (error)
+ goto out;
+ xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+ cur = NULL;
+
+ /* Collect rmaps for the cntbt. */
+ cur = xfs_allocbt_init_cursor(mp, sc->tp, sc->sa.agf_bp, sc->sa.agno,
+ XFS_BTNUM_CNT);
+ error = xfs_btree_visit_blocks(cur, xfs_repair_rmapbt_visit_btblock,
+ &rr);
+ if (error)
+ goto out;
+ xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+ cur = NULL;
+ freesp_btblocks = rr.btblocks;
+
+ /* Collect rmaps for the inode btree. */
+ cur = xfs_inobt_init_cursor(mp, sc->tp, sc->sa.agi_bp, sc->sa.agno,
+ XFS_BTNUM_INO);
+ error = xfs_btree_query_all(cur, xfs_repair_rmapbt_inodes, &rr);
+ if (error)
+ goto out;
+ xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+
+ /* If there are no inodes, we have to include the inobt root. */
+ agi = XFS_BUF_TO_AGI(sc->sa.agi_bp);
+ if (agi->agi_count == cpu_to_be32(0)) {
+ error = xfs_repair_rmapbt_new_rmap(&rr,
+ be32_to_cpu(agi->agi_root), 1,
+ XFS_RMAP_OWN_INOBT, 0, 0);
+ if (error)
+ goto out;
+ }
+
+ /* Collect rmaps for the free inode btree. */
+ if (xfs_sb_version_hasfinobt(&mp->m_sb)) {
+ rr.owner = XFS_RMAP_OWN_INOBT;
+ cur = xfs_inobt_init_cursor(mp, sc->tp, sc->sa.agi_bp,
+ sc->sa.agno, XFS_BTNUM_FINO);
+ error = xfs_btree_visit_blocks(cur,
+ xfs_repair_rmapbt_visit_btblock, &rr);
+ if (error)
+ goto out;
+ xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+ cur = NULL;
+ }
+
+ /* Collect rmaps for the refcount btree. */
+ if (xfs_sb_version_hasreflink(&mp->m_sb)) {
+ union xfs_btree_irec low;
+ union xfs_btree_irec high;
+
+ rr.owner = XFS_RMAP_OWN_REFC;
+ cur = xfs_refcountbt_init_cursor(mp, sc->tp, sc->sa.agf_bp,
+ sc->sa.agno, NULL);
+ error = xfs_btree_visit_blocks(cur,
+ xfs_repair_rmapbt_visit_btblock, &rr);
+ if (error)
+ goto out;
+
+ /* Collect rmaps for CoW staging extents. */
+ memset(&low, 0, sizeof(low));
+ low.rc.rc_startblock = XFS_REFC_COW_START;
+ memset(&high, 0xFF, sizeof(high));
+ error = xfs_btree_query_range(cur, &low, &high,
+ xfs_repair_rmapbt_refcount, &rr);
+ if (error)
+ goto out;
+ xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+ cur = NULL;
+ }
+
+ /* Iterate all AGs for inodes. */
+ for (ag = 0; ag < mp->m_sb.sb_agcount; ag++) {
+ error = xfs_ialloc_read_agi(mp, sc->tp, ag, &bp);
+ if (error)
+ goto out;
+ cur = xfs_inobt_init_cursor(mp, sc->tp, bp, ag, XFS_BTNUM_INO);
+ error = xfs_btree_query_all(cur, xfs_repair_rmapbt_scan_inobt,
+ &rr);
+ if (error)
+ goto out;
+ xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+ cur = NULL;
+ xfs_trans_brelse(sc->tp, bp);
+ bp = NULL;
+ }
+
+ /* Do we actually have enough space to do this? */
+ if (!xfs_repair_ag_has_space(pag,
+ xfs_rmapbt_calc_size(mp, rr.nr_records),
+ XFS_AG_RESV_RMAPBT)) {
+ error = -ENOSPC;
+ goto out;
+ }
+
+ /* Initialize a new rmapbt root. */
+ xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_UNKNOWN);
+ agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
+ error = xfs_repair_alloc_ag_block(sc, &oinfo, &btfsb,
+ XFS_AG_RESV_RMAPBT);
+ if (error)
+ goto out;
+ error = xfs_repair_init_btblock(sc, btfsb, &bp, XFS_BTNUM_RMAP,
+ &xfs_rmapbt_buf_ops);
+ if (error)
+ goto out;
+ agf->agf_roots[XFS_BTNUM_RMAPi] = cpu_to_be32(XFS_FSB_TO_AGBNO(mp,
+ btfsb));
+ agf->agf_levels[XFS_BTNUM_RMAPi] = cpu_to_be32(1);
+ agf->agf_rmap_blocks = cpu_to_be32(1);
+
+ /* Reset the perag info. */
+ pag->pagf_btreeblks = freesp_btblocks - 2;
+ pag->pagf_levels[XFS_BTNUM_RMAPi] =
+ be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAPi]);
+
+ /* Now reset the AGF counters. */
+ agf->agf_btreeblks = cpu_to_be32(pag->pagf_btreeblks);
+ xfs_alloc_log_agf(sc->tp, sc->sa.agf_bp, XFS_AGF_ROOTS |
+ XFS_AGF_LEVELS | XFS_AGF_RMAP_BLOCKS |
+ XFS_AGF_BTREEBLKS);
+ bp = NULL;
+ error = xfs_repair_roll_ag_trans(sc);
+ if (error)
+ goto out;
+
+ /* Insert all the metadata rmaps. */
+ list_sort(NULL, &rr.rmaplist, xfs_repair_rmapbt_extent_cmp);
+ list_for_each_entry_safe(rre, n, &rr.rmaplist, list) {
+ /* Add the rmap. */
+ cur = xfs_rmapbt_init_cursor(mp, sc->tp, sc->sa.agf_bp,
+ sc->sa.agno);
+ error = xfs_rmap_map_raw(cur, &rre->rmap);
+ if (error)
+ goto out;
+ xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+ cur = NULL;
+
+ error = xfs_repair_roll_ag_trans(sc);
+ if (error)
+ goto out;
+
+ list_del(&rre->list);
+ kmem_free(rre);
+
+ /*
+ * Ensure the freelist is full, but don't let it shrink.
+ * The rmapbt isn't fully set up yet, which means that
+ * the current AGFL blocks might not be reflected in the
+ * rmapbt, which is a problem if we want to unmap blocks
+ * from the AGFL.
+ */
+ error = xfs_repair_fix_freelist(sc, false);
+ if (error)
+ goto out;
+ }
+
+ /* Compute free space from the new rmapbt. */
+ rr.next_bno = 0;
+ cur = xfs_rmapbt_init_cursor(mp, sc->tp, sc->sa.agf_bp, sc->sa.agno);
+ error = xfs_rmap_query_all(cur, xfs_repair_rmapbt_record_rmap_freesp,
+ &rr);
+ if (error)
+ goto out;
+ xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+ cur = NULL;
+
+ /* Insert a record for space between the last rmap and EOAG. */
+ agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
+ agend = be32_to_cpu(agf->agf_length);
+ if (rr.next_bno < agend) {
+ btfsb = XFS_AGB_TO_FSB(mp, sc->sa.agno, rr.next_bno);
+ error = xfs_repair_collect_btree_extent(sc, &rr.rmap_freelist,
+ btfsb, agend - rr.next_bno);
+ if (error)
+ goto out;
+ }
+
+ /* Compute free space from the existing bnobt. */
+ cur = xfs_allocbt_init_cursor(mp, sc->tp, sc->sa.agf_bp, sc->sa.agno,
+ XFS_BTNUM_BNO);
+ error = xfs_alloc_query_all(cur, xfs_repair_rmapbt_record_bno_freesp,
+ &rr);
+ if (error)
+ goto out;
+ xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+ cur = NULL;
+
+ /*
+ * Free the "free" blocks that the new rmapbt knows about but
+ * the old bnobt doesn't. These are the old rmapbt blocks.
+ */
+ error = xfs_repair_subtract_extents(sc, &rr.rmap_freelist,
+ &rr.bno_freelist);
+ if (error)
+ goto out;
+ xfs_repair_cancel_btree_extents(sc, &rr.bno_freelist);
+ error = xfs_repair_invalidate_blocks(sc, &rr.rmap_freelist);
+ if (error) {
+ goto out;
+ }
+ return xfs_repair_reap_btree_extents(sc, &rr.rmap_freelist, &oinfo,
+ XFS_AG_RESV_RMAPBT);
+out:
+ if (cur)
+ xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+ if (bp)
+ xfs_trans_brelse(sc->tp, bp);
+ xfs_repair_cancel_btree_extents(sc, &rr.bno_freelist);
+ xfs_repair_cancel_btree_extents(sc, &rr.rmap_freelist);
+ list_for_each_entry_safe(rre, n, &rr.rmaplist, list) {
+ list_del(&rre->list);
+ kmem_free(rre);
+ }
+ return error;
+}
+#undef RMAP
diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index 95f82c7f77f6..d79696c23a93 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -178,6 +178,8 @@ xfs_scrub_teardown(
struct xfs_inode *ip_in,
int error)
{
+ int err2;
+
xfs_scrub_ag_free(sc, &sc->sa);
if (sc->tp) {
if (error == 0 && (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR))
@@ -194,6 +196,12 @@ xfs_scrub_teardown(
iput(VFS_I(sc->ip));
sc->ip = NULL;
}
+ if (sc->fs_frozen) {
+ err2 = xfs_repair_fs_thaw(sc);
+ if (!error && err2)
+ error = err2;
+ sc->fs_frozen = false;
+ }
if (sc->has_quotaofflock)
mutex_unlock(&sc->mp->m_quotainfo->qi_quotaofflock);
if (sc->buf) {
@@ -266,7 +274,7 @@ static const struct xfs_scrub_meta_ops meta_scrub_ops[] = {
.setup = xfs_scrub_setup_ag_rmapbt,
.scrub = xfs_scrub_rmapbt,
.has = xfs_sb_version_hasrmapbt,
- .repair = xfs_repair_notsupported,
+ .repair = xfs_repair_rmapbt,
},
[XFS_SCRUB_TYPE_REFCNTBT] = { /* refcountbt */
.type = ST_PERAG,
@@ -512,6 +520,8 @@ xfs_scrub_metadata(

xfs_scrub_experimental_warning(mp);

+ atomic_inc(&mp->m_scrubbers);
+
retry_op:
/* Set up for the operation. */
memset(&sc, 0, sizeof(sc));
@@ -534,7 +544,7 @@ xfs_scrub_metadata(
*/
error = xfs_scrub_teardown(&sc, ip, 0);
if (error)
- goto out;
+ goto out_dec;
try_harder = true;
goto retry_op;
} else if (error)
@@ -570,7 +580,7 @@ xfs_scrub_metadata(
error = xfs_scrub_teardown(&sc, ip, 0);
if (error) {
xfs_repair_failure(mp);
- goto out;
+ goto out_dec;
}
goto retry_op;
}
@@ -580,6 +590,8 @@ xfs_scrub_metadata(
xfs_scrub_postmortem(&sc);
out_teardown:
error = xfs_scrub_teardown(&sc, ip, error);
+out_dec:
+ atomic_dec(&mp->m_scrubbers);
out:
trace_xfs_scrub_done(ip, sm, error);
if (error == -EFSCORRUPTED || error == -EFSBADCRC) {
diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h
index 636424d5e2ee..d4141b336491 100644
--- a/fs/xfs/scrub/scrub.h
+++ b/fs/xfs/scrub/scrub.h
@@ -69,6 +69,7 @@ struct xfs_scrub_ag {

struct xfs_scrub_context {
/* General scrub state. */
+ struct inode *frozen_inode_list;
struct xfs_mount *mp;
struct xfs_scrub_metadata *sm;
const struct xfs_scrub_meta_ops *ops;
@@ -78,6 +79,7 @@ struct xfs_scrub_context {
uint ilock_flags;
bool try_harder;
bool has_quotaofflock;
+ bool fs_frozen;

/* State tracking for single-AG operations. */
struct xfs_scrub_ag sa;
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 10b90bbc5162..44ad46182077 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -205,6 +205,7 @@ typedef struct xfs_mount {
unsigned int *m_errortag;
struct xfs_kobj m_errortag_kobj;
#endif
+ atomic_t m_scrubbers; /* # of active scrub processes */
} xfs_mount_t;

/*
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 39e5ec3d407f..7f5d335a3f70 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1457,6 +1457,30 @@ xfs_fs_unfreeze(
return 0;
}

+/* Don't let userspace freeze while we're scrubbing the filesystem. */
+STATIC int
+xfs_fs_freeze_super(
+ struct super_block *sb)
+{
+ struct xfs_mount *mp = XFS_M(sb);
+
+ if (atomic_read(&mp->m_scrubbers) > 0)
+ return -EBUSY;
+ return freeze_super(sb);
+}
+
+/* Don't let userspace thaw while we're scrubbing the filesystem. */
+STATIC int
+xfs_fs_thaw_super(
+ struct super_block *sb)
+{
+ struct xfs_mount *mp = XFS_M(sb);
+
+ if (atomic_read(&mp->m_scrubbers) > 0)
+ return -EBUSY;
+ return thaw_super(sb);
+}
+
STATIC int
xfs_fs_show_options(
struct seq_file *m,
@@ -1595,6 +1619,7 @@ xfs_mount_alloc(
spin_lock_init(&mp->m_perag_lock);
mutex_init(&mp->m_growlock);
atomic_set(&mp->m_active_trans, 0);
+ atomic_set(&mp->m_scrubbers, 0);
INIT_DELAYED_WORK(&mp->m_reclaim_work, xfs_reclaim_worker);
INIT_DELAYED_WORK(&mp->m_eofblocks_work, xfs_eofblocks_worker);
INIT_DELAYED_WORK(&mp->m_cowblocks_work, xfs_cowblocks_worker);
@@ -1852,6 +1877,8 @@ static const struct super_operations xfs_super_operations = {
.show_options = xfs_fs_show_options,
.nr_cached_objects = xfs_fs_nr_cached_objects,
.free_cached_objects = xfs_fs_free_cached_objects,
+ .freeze_super = xfs_fs_freeze_super,
+ .thaw_super = xfs_fs_thaw_super,
};

static struct file_system_type xfs_fs_type = {
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 5c24e66170fe..5583c20a91fe 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -324,7 +324,12 @@ xfs_trans_alloc(
if (!(flags & XFS_TRANS_NO_WRITECOUNT))
sb_start_intwrite(mp->m_super);

- WARN_ON(mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE);
+ /*
+ * Scrub is allowed to freeze the filesystem in order to obtain
+ * exclusive access to the filesystem.
+ */
+ WARN_ON(atomic_read(&mp->m_scrubbers) == 0 &&
+ mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE);
atomic_inc(&mp->m_active_trans);

tp = kmem_zone_zalloc(xfs_trans_zone,