Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / fs / xfs / xfs_qm.c
diff --git a/kernel/fs/xfs/xfs_qm.c b/kernel/fs/xfs/xfs_qm.c
new file mode 100644 (file)
index 0000000..5538468
--- /dev/null
@@ -0,0 +1,1939 @@
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * 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.
+ *
+ * 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_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_sb.h"
+#include "xfs_mount.h"
+#include "xfs_inode.h"
+#include "xfs_ialloc.h"
+#include "xfs_itable.h"
+#include "xfs_quota.h"
+#include "xfs_error.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_trans.h"
+#include "xfs_trans_space.h"
+#include "xfs_qm.h"
+#include "xfs_trace.h"
+#include "xfs_icache.h"
+#include "xfs_cksum.h"
+
+/*
+ * The global quota manager. There is only one of these for the entire
+ * system, _not_ one per file system. XQM keeps track of the overall
+ * quota functionality, including maintaining the freelist and hash
+ * tables of dquots.
+ */
+STATIC int     xfs_qm_init_quotainos(xfs_mount_t *);
+STATIC int     xfs_qm_init_quotainfo(xfs_mount_t *);
+
+
+STATIC void    xfs_qm_dqfree_one(struct xfs_dquot *dqp);
+/*
+ * We use the batch lookup interface to iterate over the dquots as it
+ * currently is the only interface into the radix tree code that allows
+ * fuzzy lookups instead of exact matches.  Holding the lock over multiple
+ * operations is fine as all callers are used either during mount/umount
+ * or quotaoff.
+ */
+#define XFS_DQ_LOOKUP_BATCH    32
+
+STATIC int
+xfs_qm_dquot_walk(
+       struct xfs_mount        *mp,
+       int                     type,
+       int                     (*execute)(struct xfs_dquot *dqp, void *data),
+       void                    *data)
+{
+       struct xfs_quotainfo    *qi = mp->m_quotainfo;
+       struct radix_tree_root  *tree = xfs_dquot_tree(qi, type);
+       uint32_t                next_index;
+       int                     last_error = 0;
+       int                     skipped;
+       int                     nr_found;
+
+restart:
+       skipped = 0;
+       next_index = 0;
+       nr_found = 0;
+
+       while (1) {
+               struct xfs_dquot *batch[XFS_DQ_LOOKUP_BATCH];
+               int             error = 0;
+               int             i;
+
+               mutex_lock(&qi->qi_tree_lock);
+               nr_found = radix_tree_gang_lookup(tree, (void **)batch,
+                                       next_index, XFS_DQ_LOOKUP_BATCH);
+               if (!nr_found) {
+                       mutex_unlock(&qi->qi_tree_lock);
+                       break;
+               }
+
+               for (i = 0; i < nr_found; i++) {
+                       struct xfs_dquot *dqp = batch[i];
+
+                       next_index = be32_to_cpu(dqp->q_core.d_id) + 1;
+
+                       error = execute(batch[i], data);
+                       if (error == -EAGAIN) {
+                               skipped++;
+                               continue;
+                       }
+                       if (error && last_error != -EFSCORRUPTED)
+                               last_error = error;
+               }
+
+               mutex_unlock(&qi->qi_tree_lock);
+
+               /* bail out if the filesystem is corrupted.  */
+               if (last_error == -EFSCORRUPTED) {
+                       skipped = 0;
+                       break;
+               }
+       }
+
+       if (skipped) {
+               delay(1);
+               goto restart;
+       }
+
+       return last_error;
+}
+
+
+/*
+ * Purge a dquot from all tracking data structures and free it.
+ */
+STATIC int
+xfs_qm_dqpurge(
+       struct xfs_dquot        *dqp,
+       void                    *data)
+{
+       struct xfs_mount        *mp = dqp->q_mount;
+       struct xfs_quotainfo    *qi = mp->m_quotainfo;
+
+       xfs_dqlock(dqp);
+       if ((dqp->dq_flags & XFS_DQ_FREEING) || dqp->q_nrefs != 0) {
+               xfs_dqunlock(dqp);
+               return -EAGAIN;
+       }
+
+       dqp->dq_flags |= XFS_DQ_FREEING;
+
+       xfs_dqflock(dqp);
+
+       /*
+        * If we are turning this type of quotas off, we don't care
+        * about the dirty metadata sitting in this dquot. OTOH, if
+        * we're unmounting, we do care, so we flush it and wait.
+        */
+       if (XFS_DQ_IS_DIRTY(dqp)) {
+               struct xfs_buf  *bp = NULL;
+               int             error;
+
+               /*
+                * We don't care about getting disk errors here. We need
+                * to purge this dquot anyway, so we go ahead regardless.
+                */
+               error = xfs_qm_dqflush(dqp, &bp);
+               if (error) {
+                       xfs_warn(mp, "%s: dquot %p flush failed",
+                               __func__, dqp);
+               } else {
+                       error = xfs_bwrite(bp);
+                       xfs_buf_relse(bp);
+               }
+               xfs_dqflock(dqp);
+       }
+
+       ASSERT(atomic_read(&dqp->q_pincount) == 0);
+       ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
+              !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));
+
+       xfs_dqfunlock(dqp);
+       xfs_dqunlock(dqp);
+
+       radix_tree_delete(xfs_dquot_tree(qi, dqp->q_core.d_flags),
+                         be32_to_cpu(dqp->q_core.d_id));
+       qi->qi_dquots--;
+
+       /*
+        * We move dquots to the freelist as soon as their reference count
+        * hits zero, so it really should be on the freelist here.
+        */
+       ASSERT(!list_empty(&dqp->q_lru));
+       list_lru_del(&qi->qi_lru, &dqp->q_lru);
+       XFS_STATS_DEC(xs_qm_dquot_unused);
+
+       xfs_qm_dqdestroy(dqp);
+       return 0;
+}
+
+/*
+ * Purge the dquot cache.
+ */
+void
+xfs_qm_dqpurge_all(
+       struct xfs_mount        *mp,
+       uint                    flags)
+{
+       if (flags & XFS_QMOPT_UQUOTA)
+               xfs_qm_dquot_walk(mp, XFS_DQ_USER, xfs_qm_dqpurge, NULL);
+       if (flags & XFS_QMOPT_GQUOTA)
+               xfs_qm_dquot_walk(mp, XFS_DQ_GROUP, xfs_qm_dqpurge, NULL);
+       if (flags & XFS_QMOPT_PQUOTA)
+               xfs_qm_dquot_walk(mp, XFS_DQ_PROJ, xfs_qm_dqpurge, NULL);
+}
+
+/*
+ * Just destroy the quotainfo structure.
+ */
+void
+xfs_qm_unmount(
+       struct xfs_mount        *mp)
+{
+       if (mp->m_quotainfo) {
+               xfs_qm_dqpurge_all(mp, XFS_QMOPT_QUOTALL);
+               xfs_qm_destroy_quotainfo(mp);
+       }
+}
+
+/*
+ * Called from the vfsops layer.
+ */
+void
+xfs_qm_unmount_quotas(
+       xfs_mount_t     *mp)
+{
+       /*
+        * Release the dquots that root inode, et al might be holding,
+        * before we flush quotas and blow away the quotainfo structure.
+        */
+       ASSERT(mp->m_rootip);
+       xfs_qm_dqdetach(mp->m_rootip);
+       if (mp->m_rbmip)
+               xfs_qm_dqdetach(mp->m_rbmip);
+       if (mp->m_rsumip)
+               xfs_qm_dqdetach(mp->m_rsumip);
+
+       /*
+        * Release the quota inodes.
+        */
+       if (mp->m_quotainfo) {
+               if (mp->m_quotainfo->qi_uquotaip) {
+                       IRELE(mp->m_quotainfo->qi_uquotaip);
+                       mp->m_quotainfo->qi_uquotaip = NULL;
+               }
+               if (mp->m_quotainfo->qi_gquotaip) {
+                       IRELE(mp->m_quotainfo->qi_gquotaip);
+                       mp->m_quotainfo->qi_gquotaip = NULL;
+               }
+               if (mp->m_quotainfo->qi_pquotaip) {
+                       IRELE(mp->m_quotainfo->qi_pquotaip);
+                       mp->m_quotainfo->qi_pquotaip = NULL;
+               }
+       }
+}
+
+STATIC int
+xfs_qm_dqattach_one(
+       xfs_inode_t     *ip,
+       xfs_dqid_t      id,
+       uint            type,
+       uint            doalloc,
+       xfs_dquot_t     **IO_idqpp)
+{
+       xfs_dquot_t     *dqp;
+       int             error;
+
+       ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+       error = 0;
+
+       /*
+        * See if we already have it in the inode itself. IO_idqpp is &i_udquot
+        * or &i_gdquot. This made the code look weird, but made the logic a lot
+        * simpler.
+        */
+       dqp = *IO_idqpp;
+       if (dqp) {
+               trace_xfs_dqattach_found(dqp);
+               return 0;
+       }
+
+       /*
+        * Find the dquot from somewhere. This bumps the reference count of
+        * dquot and returns it locked.  This can return ENOENT if dquot didn't
+        * exist on disk and we didn't ask it to allocate; ESRCH if quotas got
+        * turned off suddenly.
+        */
+       error = xfs_qm_dqget(ip->i_mount, ip, id, type,
+                            doalloc | XFS_QMOPT_DOWARN, &dqp);
+       if (error)
+               return error;
+
+       trace_xfs_dqattach_get(dqp);
+
+       /*
+        * dqget may have dropped and re-acquired the ilock, but it guarantees
+        * that the dquot returned is the one that should go in the inode.
+        */
+       *IO_idqpp = dqp;
+       xfs_dqunlock(dqp);
+       return 0;
+}
+
+static bool
+xfs_qm_need_dqattach(
+       struct xfs_inode        *ip)
+{
+       struct xfs_mount        *mp = ip->i_mount;
+
+       if (!XFS_IS_QUOTA_RUNNING(mp))
+               return false;
+       if (!XFS_IS_QUOTA_ON(mp))
+               return false;
+       if (!XFS_NOT_DQATTACHED(mp, ip))
+               return false;
+       if (xfs_is_quota_inode(&mp->m_sb, ip->i_ino))
+               return false;
+       return true;
+}
+
+/*
+ * Given a locked inode, attach dquot(s) to it, taking U/G/P-QUOTAON
+ * into account.
+ * If XFS_QMOPT_DQALLOC, the dquot(s) will be allocated if needed.
+ * Inode may get unlocked and relocked in here, and the caller must deal with
+ * the consequences.
+ */
+int
+xfs_qm_dqattach_locked(
+       xfs_inode_t     *ip,
+       uint            flags)
+{
+       xfs_mount_t     *mp = ip->i_mount;
+       int             error = 0;
+
+       if (!xfs_qm_need_dqattach(ip))
+               return 0;
+
+       ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+       if (XFS_IS_UQUOTA_ON(mp) && !ip->i_udquot) {
+               error = xfs_qm_dqattach_one(ip, ip->i_d.di_uid, XFS_DQ_USER,
+                                               flags & XFS_QMOPT_DQALLOC,
+                                               &ip->i_udquot);
+               if (error)
+                       goto done;
+               ASSERT(ip->i_udquot);
+       }
+
+       if (XFS_IS_GQUOTA_ON(mp) && !ip->i_gdquot) {
+               error = xfs_qm_dqattach_one(ip, ip->i_d.di_gid, XFS_DQ_GROUP,
+                                               flags & XFS_QMOPT_DQALLOC,
+                                               &ip->i_gdquot);
+               if (error)
+                       goto done;
+               ASSERT(ip->i_gdquot);
+       }
+
+       if (XFS_IS_PQUOTA_ON(mp) && !ip->i_pdquot) {
+               error = xfs_qm_dqattach_one(ip, xfs_get_projid(ip), XFS_DQ_PROJ,
+                                               flags & XFS_QMOPT_DQALLOC,
+                                               &ip->i_pdquot);
+               if (error)
+                       goto done;
+               ASSERT(ip->i_pdquot);
+       }
+
+done:
+       /*
+        * Don't worry about the dquots that we may have attached before any
+        * error - they'll get detached later if it has not already been done.
+        */
+       ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+       return error;
+}
+
+int
+xfs_qm_dqattach(
+       struct xfs_inode        *ip,
+       uint                    flags)
+{
+       int                     error;
+
+       if (!xfs_qm_need_dqattach(ip))
+               return 0;
+
+       xfs_ilock(ip, XFS_ILOCK_EXCL);
+       error = xfs_qm_dqattach_locked(ip, flags);
+       xfs_iunlock(ip, XFS_ILOCK_EXCL);
+
+       return error;
+}
+
+/*
+ * Release dquots (and their references) if any.
+ * The inode should be locked EXCL except when this's called by
+ * xfs_ireclaim.
+ */
+void
+xfs_qm_dqdetach(
+       xfs_inode_t     *ip)
+{
+       if (!(ip->i_udquot || ip->i_gdquot || ip->i_pdquot))
+               return;
+
+       trace_xfs_dquot_dqdetach(ip);
+
+       ASSERT(!xfs_is_quota_inode(&ip->i_mount->m_sb, ip->i_ino));
+       if (ip->i_udquot) {
+               xfs_qm_dqrele(ip->i_udquot);
+               ip->i_udquot = NULL;
+       }
+       if (ip->i_gdquot) {
+               xfs_qm_dqrele(ip->i_gdquot);
+               ip->i_gdquot = NULL;
+       }
+       if (ip->i_pdquot) {
+               xfs_qm_dqrele(ip->i_pdquot);
+               ip->i_pdquot = NULL;
+       }
+}
+
+struct xfs_qm_isolate {
+       struct list_head        buffers;
+       struct list_head        dispose;
+};
+
+static enum lru_status
+xfs_qm_dquot_isolate(
+       struct list_head        *item,
+       struct list_lru_one     *lru,
+       spinlock_t              *lru_lock,
+       void                    *arg)
+               __releases(lru_lock) __acquires(lru_lock)
+{
+       struct xfs_dquot        *dqp = container_of(item,
+                                               struct xfs_dquot, q_lru);
+       struct xfs_qm_isolate   *isol = arg;
+
+       if (!xfs_dqlock_nowait(dqp))
+               goto out_miss_busy;
+
+       /*
+        * This dquot has acquired a reference in the meantime remove it from
+        * the freelist and try again.
+        */
+       if (dqp->q_nrefs) {
+               xfs_dqunlock(dqp);
+               XFS_STATS_INC(xs_qm_dqwants);
+
+               trace_xfs_dqreclaim_want(dqp);
+               list_lru_isolate(lru, &dqp->q_lru);
+               XFS_STATS_DEC(xs_qm_dquot_unused);
+               return LRU_REMOVED;
+       }
+
+       /*
+        * If the dquot is dirty, flush it. If it's already being flushed, just
+        * skip it so there is time for the IO to complete before we try to
+        * reclaim it again on the next LRU pass.
+        */
+       if (!xfs_dqflock_nowait(dqp)) {
+               xfs_dqunlock(dqp);
+               goto out_miss_busy;
+       }
+
+       if (XFS_DQ_IS_DIRTY(dqp)) {
+               struct xfs_buf  *bp = NULL;
+               int             error;
+
+               trace_xfs_dqreclaim_dirty(dqp);
+
+               /* we have to drop the LRU lock to flush the dquot */
+               spin_unlock(lru_lock);
+
+               error = xfs_qm_dqflush(dqp, &bp);
+               if (error) {
+                       xfs_warn(dqp->q_mount, "%s: dquot %p flush failed",
+                                __func__, dqp);
+                       goto out_unlock_dirty;
+               }
+
+               xfs_buf_delwri_queue(bp, &isol->buffers);
+               xfs_buf_relse(bp);
+               goto out_unlock_dirty;
+       }
+       xfs_dqfunlock(dqp);
+
+       /*
+        * Prevent lookups now that we are past the point of no return.
+        */
+       dqp->dq_flags |= XFS_DQ_FREEING;
+       xfs_dqunlock(dqp);
+
+       ASSERT(dqp->q_nrefs == 0);
+       list_lru_isolate_move(lru, &dqp->q_lru, &isol->dispose);
+       XFS_STATS_DEC(xs_qm_dquot_unused);
+       trace_xfs_dqreclaim_done(dqp);
+       XFS_STATS_INC(xs_qm_dqreclaims);
+       return LRU_REMOVED;
+
+out_miss_busy:
+       trace_xfs_dqreclaim_busy(dqp);
+       XFS_STATS_INC(xs_qm_dqreclaim_misses);
+       return LRU_SKIP;
+
+out_unlock_dirty:
+       trace_xfs_dqreclaim_busy(dqp);
+       XFS_STATS_INC(xs_qm_dqreclaim_misses);
+       xfs_dqunlock(dqp);
+       spin_lock(lru_lock);
+       return LRU_RETRY;
+}
+
+static unsigned long
+xfs_qm_shrink_scan(
+       struct shrinker         *shrink,
+       struct shrink_control   *sc)
+{
+       struct xfs_quotainfo    *qi = container_of(shrink,
+                                       struct xfs_quotainfo, qi_shrinker);
+       struct xfs_qm_isolate   isol;
+       unsigned long           freed;
+       int                     error;
+
+       if ((sc->gfp_mask & (__GFP_FS|__GFP_WAIT)) != (__GFP_FS|__GFP_WAIT))
+               return 0;
+
+       INIT_LIST_HEAD(&isol.buffers);
+       INIT_LIST_HEAD(&isol.dispose);
+
+       freed = list_lru_shrink_walk(&qi->qi_lru, sc,
+                                    xfs_qm_dquot_isolate, &isol);
+
+       error = xfs_buf_delwri_submit(&isol.buffers);
+       if (error)
+               xfs_warn(NULL, "%s: dquot reclaim failed", __func__);
+
+       while (!list_empty(&isol.dispose)) {
+               struct xfs_dquot        *dqp;
+
+               dqp = list_first_entry(&isol.dispose, struct xfs_dquot, q_lru);
+               list_del_init(&dqp->q_lru);
+               xfs_qm_dqfree_one(dqp);
+       }
+
+       return freed;
+}
+
+static unsigned long
+xfs_qm_shrink_count(
+       struct shrinker         *shrink,
+       struct shrink_control   *sc)
+{
+       struct xfs_quotainfo    *qi = container_of(shrink,
+                                       struct xfs_quotainfo, qi_shrinker);
+
+       return list_lru_shrink_count(&qi->qi_lru, sc);
+}
+
+/*
+ * This initializes all the quota information that's kept in the
+ * mount structure
+ */
+STATIC int
+xfs_qm_init_quotainfo(
+       xfs_mount_t     *mp)
+{
+       xfs_quotainfo_t *qinf;
+       int             error;
+       xfs_dquot_t     *dqp;
+
+       ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+
+       qinf = mp->m_quotainfo = kmem_zalloc(sizeof(xfs_quotainfo_t), KM_SLEEP);
+
+       error = list_lru_init(&qinf->qi_lru);
+       if (error)
+               goto out_free_qinf;
+
+       /*
+        * See if quotainodes are setup, and if not, allocate them,
+        * and change the superblock accordingly.
+        */
+       error = xfs_qm_init_quotainos(mp);
+       if (error)
+               goto out_free_lru;
+
+       INIT_RADIX_TREE(&qinf->qi_uquota_tree, GFP_NOFS);
+       INIT_RADIX_TREE(&qinf->qi_gquota_tree, GFP_NOFS);
+       INIT_RADIX_TREE(&qinf->qi_pquota_tree, GFP_NOFS);
+       mutex_init(&qinf->qi_tree_lock);
+
+       /* mutex used to serialize quotaoffs */
+       mutex_init(&qinf->qi_quotaofflock);
+
+       /* Precalc some constants */
+       qinf->qi_dqchunklen = XFS_FSB_TO_BB(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
+       qinf->qi_dqperchunk = xfs_calc_dquots_per_chunk(qinf->qi_dqchunklen);
+
+       mp->m_qflags |= (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_CHKD);
+
+       /*
+        * We try to get the limits from the superuser's limits fields.
+        * This is quite hacky, but it is standard quota practice.
+        *
+        * We look at the USR dquot with id == 0 first, but if user quotas
+        * are not enabled we goto the GRP dquot with id == 0.
+        * We don't really care to keep separate default limits for user
+        * and group quotas, at least not at this point.
+        *
+        * Since we may not have done a quotacheck by this point, just read
+        * the dquot without attaching it to any hashtables or lists.
+        */
+       error = xfs_qm_dqread(mp, 0,
+                       XFS_IS_UQUOTA_RUNNING(mp) ? XFS_DQ_USER :
+                        (XFS_IS_GQUOTA_RUNNING(mp) ? XFS_DQ_GROUP :
+                         XFS_DQ_PROJ),
+                       XFS_QMOPT_DOWARN, &dqp);
+       if (!error) {
+               xfs_disk_dquot_t        *ddqp = &dqp->q_core;
+
+               /*
+                * The warnings and timers set the grace period given to
+                * a user or group before he or she can not perform any
+                * more writing. If it is zero, a default is used.
+                */
+               qinf->qi_btimelimit = ddqp->d_btimer ?
+                       be32_to_cpu(ddqp->d_btimer) : XFS_QM_BTIMELIMIT;
+               qinf->qi_itimelimit = ddqp->d_itimer ?
+                       be32_to_cpu(ddqp->d_itimer) : XFS_QM_ITIMELIMIT;
+               qinf->qi_rtbtimelimit = ddqp->d_rtbtimer ?
+                       be32_to_cpu(ddqp->d_rtbtimer) : XFS_QM_RTBTIMELIMIT;
+               qinf->qi_bwarnlimit = ddqp->d_bwarns ?
+                       be16_to_cpu(ddqp->d_bwarns) : XFS_QM_BWARNLIMIT;
+               qinf->qi_iwarnlimit = ddqp->d_iwarns ?
+                       be16_to_cpu(ddqp->d_iwarns) : XFS_QM_IWARNLIMIT;
+               qinf->qi_rtbwarnlimit = ddqp->d_rtbwarns ?
+                       be16_to_cpu(ddqp->d_rtbwarns) : XFS_QM_RTBWARNLIMIT;
+               qinf->qi_bhardlimit = be64_to_cpu(ddqp->d_blk_hardlimit);
+               qinf->qi_bsoftlimit = be64_to_cpu(ddqp->d_blk_softlimit);
+               qinf->qi_ihardlimit = be64_to_cpu(ddqp->d_ino_hardlimit);
+               qinf->qi_isoftlimit = be64_to_cpu(ddqp->d_ino_softlimit);
+               qinf->qi_rtbhardlimit = be64_to_cpu(ddqp->d_rtb_hardlimit);
+               qinf->qi_rtbsoftlimit = be64_to_cpu(ddqp->d_rtb_softlimit);
+
+               xfs_qm_dqdestroy(dqp);
+       } else {
+               qinf->qi_btimelimit = XFS_QM_BTIMELIMIT;
+               qinf->qi_itimelimit = XFS_QM_ITIMELIMIT;
+               qinf->qi_rtbtimelimit = XFS_QM_RTBTIMELIMIT;
+               qinf->qi_bwarnlimit = XFS_QM_BWARNLIMIT;
+               qinf->qi_iwarnlimit = XFS_QM_IWARNLIMIT;
+               qinf->qi_rtbwarnlimit = XFS_QM_RTBWARNLIMIT;
+       }
+
+       qinf->qi_shrinker.count_objects = xfs_qm_shrink_count;
+       qinf->qi_shrinker.scan_objects = xfs_qm_shrink_scan;
+       qinf->qi_shrinker.seeks = DEFAULT_SEEKS;
+       qinf->qi_shrinker.flags = SHRINKER_NUMA_AWARE;
+       register_shrinker(&qinf->qi_shrinker);
+       return 0;
+
+out_free_lru:
+       list_lru_destroy(&qinf->qi_lru);
+out_free_qinf:
+       kmem_free(qinf);
+       mp->m_quotainfo = NULL;
+       return error;
+}
+
+
+/*
+ * Gets called when unmounting a filesystem or when all quotas get
+ * turned off.
+ * This purges the quota inodes, destroys locks and frees itself.
+ */
+void
+xfs_qm_destroy_quotainfo(
+       xfs_mount_t     *mp)
+{
+       xfs_quotainfo_t *qi;
+
+       qi = mp->m_quotainfo;
+       ASSERT(qi != NULL);
+
+       unregister_shrinker(&qi->qi_shrinker);
+       list_lru_destroy(&qi->qi_lru);
+
+       if (qi->qi_uquotaip) {
+               IRELE(qi->qi_uquotaip);
+               qi->qi_uquotaip = NULL; /* paranoia */
+       }
+       if (qi->qi_gquotaip) {
+               IRELE(qi->qi_gquotaip);
+               qi->qi_gquotaip = NULL;
+       }
+       if (qi->qi_pquotaip) {
+               IRELE(qi->qi_pquotaip);
+               qi->qi_pquotaip = NULL;
+       }
+       mutex_destroy(&qi->qi_quotaofflock);
+       kmem_free(qi);
+       mp->m_quotainfo = NULL;
+}
+
+/*
+ * Create an inode and return with a reference already taken, but unlocked
+ * This is how we create quota inodes
+ */
+STATIC int
+xfs_qm_qino_alloc(
+       xfs_mount_t     *mp,
+       xfs_inode_t     **ip,
+       uint            flags)
+{
+       xfs_trans_t     *tp;
+       int             error;
+       int             committed;
+       bool            need_alloc = true;
+
+       *ip = NULL;
+       /*
+        * With superblock that doesn't have separate pquotino, we
+        * share an inode between gquota and pquota. If the on-disk
+        * superblock has GQUOTA and the filesystem is now mounted
+        * with PQUOTA, just use sb_gquotino for sb_pquotino and
+        * vice-versa.
+        */
+       if (!xfs_sb_version_has_pquotino(&mp->m_sb) &&
+                       (flags & (XFS_QMOPT_PQUOTA|XFS_QMOPT_GQUOTA))) {
+               xfs_ino_t ino = NULLFSINO;
+
+               if ((flags & XFS_QMOPT_PQUOTA) &&
+                            (mp->m_sb.sb_gquotino != NULLFSINO)) {
+                       ino = mp->m_sb.sb_gquotino;
+                       ASSERT(mp->m_sb.sb_pquotino == NULLFSINO);
+               } else if ((flags & XFS_QMOPT_GQUOTA) &&
+                            (mp->m_sb.sb_pquotino != NULLFSINO)) {
+                       ino = mp->m_sb.sb_pquotino;
+                       ASSERT(mp->m_sb.sb_gquotino == NULLFSINO);
+               }
+               if (ino != NULLFSINO) {
+                       error = xfs_iget(mp, NULL, ino, 0, 0, ip);
+                       if (error)
+                               return error;
+                       mp->m_sb.sb_gquotino = NULLFSINO;
+                       mp->m_sb.sb_pquotino = NULLFSINO;
+                       need_alloc = false;
+               }
+       }
+
+       tp = xfs_trans_alloc(mp, XFS_TRANS_QM_QINOCREATE);
+       error = xfs_trans_reserve(tp, &M_RES(mp)->tr_create,
+                                 XFS_QM_QINOCREATE_SPACE_RES(mp), 0);
+       if (error) {
+               xfs_trans_cancel(tp, 0);
+               return error;
+       }
+
+       if (need_alloc) {
+               error = xfs_dir_ialloc(&tp, NULL, S_IFREG, 1, 0, 0, 1, ip,
+                                                               &committed);
+               if (error) {
+                       xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES |
+                                        XFS_TRANS_ABORT);
+                       return error;
+               }
+       }
+
+       /*
+        * Make the changes in the superblock, and log those too.
+        * sbfields arg may contain fields other than *QUOTINO;
+        * VERSIONNUM for example.
+        */
+       spin_lock(&mp->m_sb_lock);
+       if (flags & XFS_QMOPT_SBVERSION) {
+               ASSERT(!xfs_sb_version_hasquota(&mp->m_sb));
+
+               xfs_sb_version_addquota(&mp->m_sb);
+               mp->m_sb.sb_uquotino = NULLFSINO;
+               mp->m_sb.sb_gquotino = NULLFSINO;
+               mp->m_sb.sb_pquotino = NULLFSINO;
+
+               /* qflags will get updated fully _after_ quotacheck */
+               mp->m_sb.sb_qflags = mp->m_qflags & XFS_ALL_QUOTA_ACCT;
+       }
+       if (flags & XFS_QMOPT_UQUOTA)
+               mp->m_sb.sb_uquotino = (*ip)->i_ino;
+       else if (flags & XFS_QMOPT_GQUOTA)
+               mp->m_sb.sb_gquotino = (*ip)->i_ino;
+       else
+               mp->m_sb.sb_pquotino = (*ip)->i_ino;
+       spin_unlock(&mp->m_sb_lock);
+       xfs_log_sb(tp);
+
+       error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+       if (error) {
+               ASSERT(XFS_FORCED_SHUTDOWN(mp));
+               xfs_alert(mp, "%s failed (error %d)!", __func__, error);
+       }
+       if (need_alloc)
+               xfs_finish_inode_setup(*ip);
+       return error;
+}
+
+
+STATIC void
+xfs_qm_reset_dqcounts(
+       xfs_mount_t     *mp,
+       xfs_buf_t       *bp,
+       xfs_dqid_t      id,
+       uint            type)
+{
+       struct xfs_dqblk        *dqb;
+       int                     j;
+
+       trace_xfs_reset_dqcounts(bp, _RET_IP_);
+
+       /*
+        * Reset all counters and timers. They'll be
+        * started afresh by xfs_qm_quotacheck.
+        */
+#ifdef DEBUG
+       j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
+       do_div(j, sizeof(xfs_dqblk_t));
+       ASSERT(mp->m_quotainfo->qi_dqperchunk == j);
+#endif
+       dqb = bp->b_addr;
+       for (j = 0; j < mp->m_quotainfo->qi_dqperchunk; j++) {
+               struct xfs_disk_dquot   *ddq;
+
+               ddq = (struct xfs_disk_dquot *)&dqb[j];
+
+               /*
+                * Do a sanity check, and if needed, repair the dqblk. Don't
+                * output any warnings because it's perfectly possible to
+                * find uninitialised dquot blks. See comment in xfs_dqcheck.
+                */
+               xfs_dqcheck(mp, ddq, id+j, type, XFS_QMOPT_DQREPAIR,
+                           "xfs_quotacheck");
+               /*
+                * Reset type in case we are reusing group quota file for
+                * project quotas or vice versa
+                */
+               ddq->d_flags = type;
+               ddq->d_bcount = 0;
+               ddq->d_icount = 0;
+               ddq->d_rtbcount = 0;
+               ddq->d_btimer = 0;
+               ddq->d_itimer = 0;
+               ddq->d_rtbtimer = 0;
+               ddq->d_bwarns = 0;
+               ddq->d_iwarns = 0;
+               ddq->d_rtbwarns = 0;
+
+               if (xfs_sb_version_hascrc(&mp->m_sb)) {
+                       xfs_update_cksum((char *)&dqb[j],
+                                        sizeof(struct xfs_dqblk),
+                                        XFS_DQUOT_CRC_OFF);
+               }
+       }
+}
+
+STATIC int
+xfs_qm_dqiter_bufs(
+       struct xfs_mount        *mp,
+       xfs_dqid_t              firstid,
+       xfs_fsblock_t           bno,
+       xfs_filblks_t           blkcnt,
+       uint                    flags,
+       struct list_head        *buffer_list)
+{
+       struct xfs_buf          *bp;
+       int                     error;
+       int                     type;
+
+       ASSERT(blkcnt > 0);
+       type = flags & XFS_QMOPT_UQUOTA ? XFS_DQ_USER :
+               (flags & XFS_QMOPT_PQUOTA ? XFS_DQ_PROJ : XFS_DQ_GROUP);
+       error = 0;
+
+       /*
+        * Blkcnt arg can be a very big number, and might even be
+        * larger than the log itself. So, we have to break it up into
+        * manageable-sized transactions.
+        * Note that we don't start a permanent transaction here; we might
+        * not be able to get a log reservation for the whole thing up front,
+        * and we don't really care to either, because we just discard
+        * everything if we were to crash in the middle of this loop.
+        */
+       while (blkcnt--) {
+               error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
+                             XFS_FSB_TO_DADDR(mp, bno),
+                             mp->m_quotainfo->qi_dqchunklen, 0, &bp,
+                             &xfs_dquot_buf_ops);
+
+               /*
+                * CRC and validation errors will return a EFSCORRUPTED here. If
+                * this occurs, re-read without CRC validation so that we can
+                * repair the damage via xfs_qm_reset_dqcounts(). This process
+                * will leave a trace in the log indicating corruption has
+                * been detected.
+                */
+               if (error == -EFSCORRUPTED) {
+                       error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
+                                     XFS_FSB_TO_DADDR(mp, bno),
+                                     mp->m_quotainfo->qi_dqchunklen, 0, &bp,
+                                     NULL);
+               }
+
+               if (error)
+                       break;
+
+               /*
+                * A corrupt buffer might not have a verifier attached, so
+                * make sure we have the correct one attached before writeback
+                * occurs.
+                */
+               bp->b_ops = &xfs_dquot_buf_ops;
+               xfs_qm_reset_dqcounts(mp, bp, firstid, type);
+               xfs_buf_delwri_queue(bp, buffer_list);
+               xfs_buf_relse(bp);
+
+               /* goto the next block. */
+               bno++;
+               firstid += mp->m_quotainfo->qi_dqperchunk;
+       }
+
+       return error;
+}
+
+/*
+ * Iterate over all allocated USR/GRP/PRJ dquots in the system, calling a
+ * caller supplied function for every chunk of dquots that we find.
+ */
+STATIC int
+xfs_qm_dqiterate(
+       struct xfs_mount        *mp,
+       struct xfs_inode        *qip,
+       uint                    flags,
+       struct list_head        *buffer_list)
+{
+       struct xfs_bmbt_irec    *map;
+       int                     i, nmaps;       /* number of map entries */
+       int                     error;          /* return value */
+       xfs_fileoff_t           lblkno;
+       xfs_filblks_t           maxlblkcnt;
+       xfs_dqid_t              firstid;
+       xfs_fsblock_t           rablkno;
+       xfs_filblks_t           rablkcnt;
+
+       error = 0;
+       /*
+        * This looks racy, but we can't keep an inode lock across a
+        * trans_reserve. But, this gets called during quotacheck, and that
+        * happens only at mount time which is single threaded.
+        */
+       if (qip->i_d.di_nblocks == 0)
+               return 0;
+
+       map = kmem_alloc(XFS_DQITER_MAP_SIZE * sizeof(*map), KM_SLEEP);
+
+       lblkno = 0;
+       maxlblkcnt = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
+       do {
+               uint            lock_mode;
+
+               nmaps = XFS_DQITER_MAP_SIZE;
+               /*
+                * We aren't changing the inode itself. Just changing
+                * some of its data. No new blocks are added here, and
+                * the inode is never added to the transaction.
+                */
+               lock_mode = xfs_ilock_data_map_shared(qip);
+               error = xfs_bmapi_read(qip, lblkno, maxlblkcnt - lblkno,
+                                      map, &nmaps, 0);
+               xfs_iunlock(qip, lock_mode);
+               if (error)
+                       break;
+
+               ASSERT(nmaps <= XFS_DQITER_MAP_SIZE);
+               for (i = 0; i < nmaps; i++) {
+                       ASSERT(map[i].br_startblock != DELAYSTARTBLOCK);
+                       ASSERT(map[i].br_blockcount);
+
+
+                       lblkno += map[i].br_blockcount;
+
+                       if (map[i].br_startblock == HOLESTARTBLOCK)
+                               continue;
+
+                       firstid = (xfs_dqid_t) map[i].br_startoff *
+                               mp->m_quotainfo->qi_dqperchunk;
+                       /*
+                        * Do a read-ahead on the next extent.
+                        */
+                       if ((i+1 < nmaps) &&
+                           (map[i+1].br_startblock != HOLESTARTBLOCK)) {
+                               rablkcnt =  map[i+1].br_blockcount;
+                               rablkno = map[i+1].br_startblock;
+                               while (rablkcnt--) {
+                                       xfs_buf_readahead(mp->m_ddev_targp,
+                                              XFS_FSB_TO_DADDR(mp, rablkno),
+                                              mp->m_quotainfo->qi_dqchunklen,
+                                              &xfs_dquot_buf_ops);
+                                       rablkno++;
+                               }
+                       }
+                       /*
+                        * Iterate thru all the blks in the extent and
+                        * reset the counters of all the dquots inside them.
+                        */
+                       error = xfs_qm_dqiter_bufs(mp, firstid,
+                                                  map[i].br_startblock,
+                                                  map[i].br_blockcount,
+                                                  flags, buffer_list);
+                       if (error)
+                               goto out;
+               }
+       } while (nmaps > 0);
+
+out:
+       kmem_free(map);
+       return error;
+}
+
+/*
+ * Called by dqusage_adjust in doing a quotacheck.
+ *
+ * Given the inode, and a dquot id this updates both the incore dqout as well
+ * as the buffer copy. This is so that once the quotacheck is done, we can
+ * just log all the buffers, as opposed to logging numerous updates to
+ * individual dquots.
+ */
+STATIC int
+xfs_qm_quotacheck_dqadjust(
+       struct xfs_inode        *ip,
+       xfs_dqid_t              id,
+       uint                    type,
+       xfs_qcnt_t              nblks,
+       xfs_qcnt_t              rtblks)
+{
+       struct xfs_mount        *mp = ip->i_mount;
+       struct xfs_dquot        *dqp;
+       int                     error;
+
+       error = xfs_qm_dqget(mp, ip, id, type,
+                            XFS_QMOPT_DQALLOC | XFS_QMOPT_DOWARN, &dqp);
+       if (error) {
+               /*
+                * Shouldn't be able to turn off quotas here.
+                */
+               ASSERT(error != -ESRCH);
+               ASSERT(error != -ENOENT);
+               return error;
+       }
+
+       trace_xfs_dqadjust(dqp);
+
+       /*
+        * Adjust the inode count and the block count to reflect this inode's
+        * resource usage.
+        */
+       be64_add_cpu(&dqp->q_core.d_icount, 1);
+       dqp->q_res_icount++;
+       if (nblks) {
+               be64_add_cpu(&dqp->q_core.d_bcount, nblks);
+               dqp->q_res_bcount += nblks;
+       }
+       if (rtblks) {
+               be64_add_cpu(&dqp->q_core.d_rtbcount, rtblks);
+               dqp->q_res_rtbcount += rtblks;
+       }
+
+       /*
+        * Set default limits, adjust timers (since we changed usages)
+        *
+        * There are no timers for the default values set in the root dquot.
+        */
+       if (dqp->q_core.d_id) {
+               xfs_qm_adjust_dqlimits(mp, dqp);
+               xfs_qm_adjust_dqtimers(mp, &dqp->q_core);
+       }
+
+       dqp->dq_flags |= XFS_DQ_DIRTY;
+       xfs_qm_dqput(dqp);
+       return 0;
+}
+
+STATIC int
+xfs_qm_get_rtblks(
+       xfs_inode_t     *ip,
+       xfs_qcnt_t      *O_rtblks)
+{
+       xfs_filblks_t   rtblks;                 /* total rt blks */
+       xfs_extnum_t    idx;                    /* extent record index */
+       xfs_ifork_t     *ifp;                   /* inode fork pointer */
+       xfs_extnum_t    nextents;               /* number of extent entries */
+       int             error;
+
+       ASSERT(XFS_IS_REALTIME_INODE(ip));
+       ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+       if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+               if ((error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK)))
+                       return error;
+       }
+       rtblks = 0;
+       nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+       for (idx = 0; idx < nextents; idx++)
+               rtblks += xfs_bmbt_get_blockcount(xfs_iext_get_ext(ifp, idx));
+       *O_rtblks = (xfs_qcnt_t)rtblks;
+       return 0;
+}
+
+/*
+ * callback routine supplied to bulkstat(). Given an inumber, find its
+ * dquots and update them to account for resources taken by that inode.
+ */
+/* ARGSUSED */
+STATIC int
+xfs_qm_dqusage_adjust(
+       xfs_mount_t     *mp,            /* mount point for filesystem */
+       xfs_ino_t       ino,            /* inode number to get data for */
+       void            __user *buffer, /* not used */
+       int             ubsize,         /* not used */
+       int             *ubused,        /* not used */
+       int             *res)           /* result code value */
+{
+       xfs_inode_t     *ip;
+       xfs_qcnt_t      nblks, rtblks = 0;
+       int             error;
+
+       ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+
+       /*
+        * rootino must have its resources accounted for, not so with the quota
+        * inodes.
+        */
+       if (xfs_is_quota_inode(&mp->m_sb, ino)) {
+               *res = BULKSTAT_RV_NOTHING;
+               return -EINVAL;
+       }
+
+       /*
+        * We don't _need_ to take the ilock EXCL. However, the xfs_qm_dqget
+        * interface expects the inode to be exclusively locked because that's
+        * the case in all other instances. It's OK that we do this because
+        * quotacheck is done only at mount time.
+        */
+       error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_EXCL, &ip);
+       if (error) {
+               *res = BULKSTAT_RV_NOTHING;
+               return error;
+       }
+
+       ASSERT(ip->i_delayed_blks == 0);
+
+       if (XFS_IS_REALTIME_INODE(ip)) {
+               /*
+                * Walk thru the extent list and count the realtime blocks.
+                */
+               error = xfs_qm_get_rtblks(ip, &rtblks);
+               if (error)
+                       goto error0;
+       }
+
+       nblks = (xfs_qcnt_t)ip->i_d.di_nblocks - rtblks;
+
+       /*
+        * Add the (disk blocks and inode) resources occupied by this
+        * inode to its dquots. We do this adjustment in the incore dquot,
+        * and also copy the changes to its buffer.
+        * We don't care about putting these changes in a transaction
+        * envelope because if we crash in the middle of a 'quotacheck'
+        * we have to start from the beginning anyway.
+        * Once we're done, we'll log all the dquot bufs.
+        *
+        * The *QUOTA_ON checks below may look pretty racy, but quotachecks
+        * and quotaoffs don't race. (Quotachecks happen at mount time only).
+        */
+       if (XFS_IS_UQUOTA_ON(mp)) {
+               error = xfs_qm_quotacheck_dqadjust(ip, ip->i_d.di_uid,
+                                                  XFS_DQ_USER, nblks, rtblks);
+               if (error)
+                       goto error0;
+       }
+
+       if (XFS_IS_GQUOTA_ON(mp)) {
+               error = xfs_qm_quotacheck_dqadjust(ip, ip->i_d.di_gid,
+                                                  XFS_DQ_GROUP, nblks, rtblks);
+               if (error)
+                       goto error0;
+       }
+
+       if (XFS_IS_PQUOTA_ON(mp)) {
+               error = xfs_qm_quotacheck_dqadjust(ip, xfs_get_projid(ip),
+                                                  XFS_DQ_PROJ, nblks, rtblks);
+               if (error)
+                       goto error0;
+       }
+
+       xfs_iunlock(ip, XFS_ILOCK_EXCL);
+       IRELE(ip);
+       *res = BULKSTAT_RV_DIDONE;
+       return 0;
+
+error0:
+       xfs_iunlock(ip, XFS_ILOCK_EXCL);
+       IRELE(ip);
+       *res = BULKSTAT_RV_GIVEUP;
+       return error;
+}
+
+STATIC int
+xfs_qm_flush_one(
+       struct xfs_dquot        *dqp,
+       void                    *data)
+{
+       struct list_head        *buffer_list = data;
+       struct xfs_buf          *bp = NULL;
+       int                     error = 0;
+
+       xfs_dqlock(dqp);
+       if (dqp->dq_flags & XFS_DQ_FREEING)
+               goto out_unlock;
+       if (!XFS_DQ_IS_DIRTY(dqp))
+               goto out_unlock;
+
+       xfs_dqflock(dqp);
+       error = xfs_qm_dqflush(dqp, &bp);
+       if (error)
+               goto out_unlock;
+
+       xfs_buf_delwri_queue(bp, buffer_list);
+       xfs_buf_relse(bp);
+out_unlock:
+       xfs_dqunlock(dqp);
+       return error;
+}
+
+/*
+ * Walk thru all the filesystem inodes and construct a consistent view
+ * of the disk quota world. If the quotacheck fails, disable quotas.
+ */
+STATIC int
+xfs_qm_quotacheck(
+       xfs_mount_t     *mp)
+{
+       int                     done, count, error, error2;
+       xfs_ino_t               lastino;
+       size_t                  structsz;
+       uint                    flags;
+       LIST_HEAD               (buffer_list);
+       struct xfs_inode        *uip = mp->m_quotainfo->qi_uquotaip;
+       struct xfs_inode        *gip = mp->m_quotainfo->qi_gquotaip;
+       struct xfs_inode        *pip = mp->m_quotainfo->qi_pquotaip;
+
+       count = INT_MAX;
+       structsz = 1;
+       lastino = 0;
+       flags = 0;
+
+       ASSERT(uip || gip || pip);
+       ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+
+       xfs_notice(mp, "Quotacheck needed: Please wait.");
+
+       /*
+        * First we go thru all the dquots on disk, USR and GRP/PRJ, and reset
+        * their counters to zero. We need a clean slate.
+        * We don't log our changes till later.
+        */
+       if (uip) {
+               error = xfs_qm_dqiterate(mp, uip, XFS_QMOPT_UQUOTA,
+                                        &buffer_list);
+               if (error)
+                       goto error_return;
+               flags |= XFS_UQUOTA_CHKD;
+       }
+
+       if (gip) {
+               error = xfs_qm_dqiterate(mp, gip, XFS_QMOPT_GQUOTA,
+                                        &buffer_list);
+               if (error)
+                       goto error_return;
+               flags |= XFS_GQUOTA_CHKD;
+       }
+
+       if (pip) {
+               error = xfs_qm_dqiterate(mp, pip, XFS_QMOPT_PQUOTA,
+                                        &buffer_list);
+               if (error)
+                       goto error_return;
+               flags |= XFS_PQUOTA_CHKD;
+       }
+
+       do {
+               /*
+                * Iterate thru all the inodes in the file system,
+                * adjusting the corresponding dquot counters in core.
+                */
+               error = xfs_bulkstat(mp, &lastino, &count,
+                                    xfs_qm_dqusage_adjust,
+                                    structsz, NULL, &done);
+               if (error)
+                       break;
+
+       } while (!done);
+
+       /*
+        * We've made all the changes that we need to make incore.  Flush them
+        * down to disk buffers if everything was updated successfully.
+        */
+       if (XFS_IS_UQUOTA_ON(mp)) {
+               error = xfs_qm_dquot_walk(mp, XFS_DQ_USER, xfs_qm_flush_one,
+                                         &buffer_list);
+       }
+       if (XFS_IS_GQUOTA_ON(mp)) {
+               error2 = xfs_qm_dquot_walk(mp, XFS_DQ_GROUP, xfs_qm_flush_one,
+                                          &buffer_list);
+               if (!error)
+                       error = error2;
+       }
+       if (XFS_IS_PQUOTA_ON(mp)) {
+               error2 = xfs_qm_dquot_walk(mp, XFS_DQ_PROJ, xfs_qm_flush_one,
+                                          &buffer_list);
+               if (!error)
+                       error = error2;
+       }
+
+       error2 = xfs_buf_delwri_submit(&buffer_list);
+       if (!error)
+               error = error2;
+
+       /*
+        * We can get this error if we couldn't do a dquot allocation inside
+        * xfs_qm_dqusage_adjust (via bulkstat). We don't care about the
+        * dirty dquots that might be cached, we just want to get rid of them
+        * and turn quotaoff. The dquots won't be attached to any of the inodes
+        * at this point (because we intentionally didn't in dqget_noattach).
+        */
+       if (error) {
+               xfs_qm_dqpurge_all(mp, XFS_QMOPT_QUOTALL);
+               goto error_return;
+       }
+
+       /*
+        * If one type of quotas is off, then it will lose its
+        * quotachecked status, since we won't be doing accounting for
+        * that type anymore.
+        */
+       mp->m_qflags &= ~XFS_ALL_QUOTA_CHKD;
+       mp->m_qflags |= flags;
+
+ error_return:
+       while (!list_empty(&buffer_list)) {
+               struct xfs_buf *bp =
+                       list_first_entry(&buffer_list, struct xfs_buf, b_list);
+               list_del_init(&bp->b_list);
+               xfs_buf_relse(bp);
+       }
+
+       if (error) {
+               xfs_warn(mp,
+       "Quotacheck: Unsuccessful (Error %d): Disabling quotas.",
+                       error);
+               /*
+                * We must turn off quotas.
+                */
+               ASSERT(mp->m_quotainfo != NULL);
+               xfs_qm_destroy_quotainfo(mp);
+               if (xfs_mount_reset_sbqflags(mp)) {
+                       xfs_warn(mp,
+                               "Quotacheck: Failed to reset quota flags.");
+               }
+       } else
+               xfs_notice(mp, "Quotacheck: Done.");
+       return error;
+}
+
+/*
+ * This is called from xfs_mountfs to start quotas and initialize all
+ * necessary data structures like quotainfo.  This is also responsible for
+ * running a quotacheck as necessary.  We are guaranteed that the superblock
+ * is consistently read in at this point.
+ *
+ * If we fail here, the mount will continue with quota turned off. We don't
+ * need to inidicate success or failure at all.
+ */
+void
+xfs_qm_mount_quotas(
+       struct xfs_mount        *mp)
+{
+       int                     error = 0;
+       uint                    sbf;
+
+       /*
+        * If quotas on realtime volumes is not supported, we disable
+        * quotas immediately.
+        */
+       if (mp->m_sb.sb_rextents) {
+               xfs_notice(mp, "Cannot turn on quotas for realtime filesystem");
+               mp->m_qflags = 0;
+               goto write_changes;
+       }
+
+       ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+
+       /*
+        * Allocate the quotainfo structure inside the mount struct, and
+        * create quotainode(s), and change/rev superblock if necessary.
+        */
+       error = xfs_qm_init_quotainfo(mp);
+       if (error) {
+               /*
+                * We must turn off quotas.
+                */
+               ASSERT(mp->m_quotainfo == NULL);
+               mp->m_qflags = 0;
+               goto write_changes;
+       }
+       /*
+        * If any of the quotas are not consistent, do a quotacheck.
+        */
+       if (XFS_QM_NEED_QUOTACHECK(mp)) {
+               error = xfs_qm_quotacheck(mp);
+               if (error) {
+                       /* Quotacheck failed and disabled quotas. */
+                       return;
+               }
+       }
+       /*
+        * If one type of quotas is off, then it will lose its
+        * quotachecked status, since we won't be doing accounting for
+        * that type anymore.
+        */
+       if (!XFS_IS_UQUOTA_ON(mp))
+               mp->m_qflags &= ~XFS_UQUOTA_CHKD;
+       if (!XFS_IS_GQUOTA_ON(mp))
+               mp->m_qflags &= ~XFS_GQUOTA_CHKD;
+       if (!XFS_IS_PQUOTA_ON(mp))
+               mp->m_qflags &= ~XFS_PQUOTA_CHKD;
+
+ write_changes:
+       /*
+        * We actually don't have to acquire the m_sb_lock at all.
+        * This can only be called from mount, and that's single threaded. XXX
+        */
+       spin_lock(&mp->m_sb_lock);
+       sbf = mp->m_sb.sb_qflags;
+       mp->m_sb.sb_qflags = mp->m_qflags & XFS_MOUNT_QUOTA_ALL;
+       spin_unlock(&mp->m_sb_lock);
+
+       if (sbf != (mp->m_qflags & XFS_MOUNT_QUOTA_ALL)) {
+               if (xfs_sync_sb(mp, false)) {
+                       /*
+                        * We could only have been turning quotas off.
+                        * We aren't in very good shape actually because
+                        * the incore structures are convinced that quotas are
+                        * off, but the on disk superblock doesn't know that !
+                        */
+                       ASSERT(!(XFS_IS_QUOTA_RUNNING(mp)));
+                       xfs_alert(mp, "%s: Superblock update failed!",
+                               __func__);
+               }
+       }
+
+       if (error) {
+               xfs_warn(mp, "Failed to initialize disk quotas.");
+               return;
+       }
+}
+
+/*
+ * This is called after the superblock has been read in and we're ready to
+ * iget the quota inodes.
+ */
+STATIC int
+xfs_qm_init_quotainos(
+       xfs_mount_t     *mp)
+{
+       struct xfs_inode        *uip = NULL;
+       struct xfs_inode        *gip = NULL;
+       struct xfs_inode        *pip = NULL;
+       int                     error;
+       uint                    flags = 0;
+
+       ASSERT(mp->m_quotainfo);
+
+       /*
+        * Get the uquota and gquota inodes
+        */
+       if (xfs_sb_version_hasquota(&mp->m_sb)) {
+               if (XFS_IS_UQUOTA_ON(mp) &&
+                   mp->m_sb.sb_uquotino != NULLFSINO) {
+                       ASSERT(mp->m_sb.sb_uquotino > 0);
+                       error = xfs_iget(mp, NULL, mp->m_sb.sb_uquotino,
+                                            0, 0, &uip);
+                       if (error)
+                               return error;
+               }
+               if (XFS_IS_GQUOTA_ON(mp) &&
+                   mp->m_sb.sb_gquotino != NULLFSINO) {
+                       ASSERT(mp->m_sb.sb_gquotino > 0);
+                       error = xfs_iget(mp, NULL, mp->m_sb.sb_gquotino,
+                                            0, 0, &gip);
+                       if (error)
+                               goto error_rele;
+               }
+               if (XFS_IS_PQUOTA_ON(mp) &&
+                   mp->m_sb.sb_pquotino != NULLFSINO) {
+                       ASSERT(mp->m_sb.sb_pquotino > 0);
+                       error = xfs_iget(mp, NULL, mp->m_sb.sb_pquotino,
+                                            0, 0, &pip);
+                       if (error)
+                               goto error_rele;
+               }
+       } else {
+               flags |= XFS_QMOPT_SBVERSION;
+       }
+
+       /*
+        * Create the three inodes, if they don't exist already. The changes
+        * made above will get added to a transaction and logged in one of
+        * the qino_alloc calls below.  If the device is readonly,
+        * temporarily switch to read-write to do this.
+        */
+       if (XFS_IS_UQUOTA_ON(mp) && uip == NULL) {
+               error = xfs_qm_qino_alloc(mp, &uip,
+                                             flags | XFS_QMOPT_UQUOTA);
+               if (error)
+                       goto error_rele;
+
+               flags &= ~XFS_QMOPT_SBVERSION;
+       }
+       if (XFS_IS_GQUOTA_ON(mp) && gip == NULL) {
+               error = xfs_qm_qino_alloc(mp, &gip,
+                                         flags | XFS_QMOPT_GQUOTA);
+               if (error)
+                       goto error_rele;
+
+               flags &= ~XFS_QMOPT_SBVERSION;
+       }
+       if (XFS_IS_PQUOTA_ON(mp) && pip == NULL) {
+               error = xfs_qm_qino_alloc(mp, &pip,
+                                         flags | XFS_QMOPT_PQUOTA);
+               if (error)
+                       goto error_rele;
+       }
+
+       mp->m_quotainfo->qi_uquotaip = uip;
+       mp->m_quotainfo->qi_gquotaip = gip;
+       mp->m_quotainfo->qi_pquotaip = pip;
+
+       return 0;
+
+error_rele:
+       if (uip)
+               IRELE(uip);
+       if (gip)
+               IRELE(gip);
+       if (pip)
+               IRELE(pip);
+       return error;
+}
+
+STATIC void
+xfs_qm_dqfree_one(
+       struct xfs_dquot        *dqp)
+{
+       struct xfs_mount        *mp = dqp->q_mount;
+       struct xfs_quotainfo    *qi = mp->m_quotainfo;
+
+       mutex_lock(&qi->qi_tree_lock);
+       radix_tree_delete(xfs_dquot_tree(qi, dqp->q_core.d_flags),
+                         be32_to_cpu(dqp->q_core.d_id));
+
+       qi->qi_dquots--;
+       mutex_unlock(&qi->qi_tree_lock);
+
+       xfs_qm_dqdestroy(dqp);
+}
+
+/* --------------- utility functions for vnodeops ---------------- */
+
+
+/*
+ * Given an inode, a uid, gid and prid make sure that we have
+ * allocated relevant dquot(s) on disk, and that we won't exceed inode
+ * quotas by creating this file.
+ * This also attaches dquot(s) to the given inode after locking it,
+ * and returns the dquots corresponding to the uid and/or gid.
+ *
+ * in  : inode (unlocked)
+ * out : udquot, gdquot with references taken and unlocked
+ */
+int
+xfs_qm_vop_dqalloc(
+       struct xfs_inode        *ip,
+       xfs_dqid_t              uid,
+       xfs_dqid_t              gid,
+       prid_t                  prid,
+       uint                    flags,
+       struct xfs_dquot        **O_udqpp,
+       struct xfs_dquot        **O_gdqpp,
+       struct xfs_dquot        **O_pdqpp)
+{
+       struct xfs_mount        *mp = ip->i_mount;
+       struct xfs_dquot        *uq = NULL;
+       struct xfs_dquot        *gq = NULL;
+       struct xfs_dquot        *pq = NULL;
+       int                     error;
+       uint                    lockflags;
+
+       if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
+               return 0;
+
+       lockflags = XFS_ILOCK_EXCL;
+       xfs_ilock(ip, lockflags);
+
+       if ((flags & XFS_QMOPT_INHERIT) && XFS_INHERIT_GID(ip))
+               gid = ip->i_d.di_gid;
+
+       /*
+        * Attach the dquot(s) to this inode, doing a dquot allocation
+        * if necessary. The dquot(s) will not be locked.
+        */
+       if (XFS_NOT_DQATTACHED(mp, ip)) {
+               error = xfs_qm_dqattach_locked(ip, XFS_QMOPT_DQALLOC);
+               if (error) {
+                       xfs_iunlock(ip, lockflags);
+                       return error;
+               }
+       }
+
+       if ((flags & XFS_QMOPT_UQUOTA) && XFS_IS_UQUOTA_ON(mp)) {
+               if (ip->i_d.di_uid != uid) {
+                       /*
+                        * What we need is the dquot that has this uid, and
+                        * if we send the inode to dqget, the uid of the inode
+                        * takes priority over what's sent in the uid argument.
+                        * We must unlock inode here before calling dqget if
+                        * we're not sending the inode, because otherwise
+                        * we'll deadlock by doing trans_reserve while
+                        * holding ilock.
+                        */
+                       xfs_iunlock(ip, lockflags);
+                       error = xfs_qm_dqget(mp, NULL, uid,
+                                                XFS_DQ_USER,
+                                                XFS_QMOPT_DQALLOC |
+                                                XFS_QMOPT_DOWARN,
+                                                &uq);
+                       if (error) {
+                               ASSERT(error != -ENOENT);
+                               return error;
+                       }
+                       /*
+                        * Get the ilock in the right order.
+                        */
+                       xfs_dqunlock(uq);
+                       lockflags = XFS_ILOCK_SHARED;
+                       xfs_ilock(ip, lockflags);
+               } else {
+                       /*
+                        * Take an extra reference, because we'll return
+                        * this to caller
+                        */
+                       ASSERT(ip->i_udquot);
+                       uq = xfs_qm_dqhold(ip->i_udquot);
+               }
+       }
+       if ((flags & XFS_QMOPT_GQUOTA) && XFS_IS_GQUOTA_ON(mp)) {
+               if (ip->i_d.di_gid != gid) {
+                       xfs_iunlock(ip, lockflags);
+                       error = xfs_qm_dqget(mp, NULL, gid,
+                                                XFS_DQ_GROUP,
+                                                XFS_QMOPT_DQALLOC |
+                                                XFS_QMOPT_DOWARN,
+                                                &gq);
+                       if (error) {
+                               ASSERT(error != -ENOENT);
+                               goto error_rele;
+                       }
+                       xfs_dqunlock(gq);
+                       lockflags = XFS_ILOCK_SHARED;
+                       xfs_ilock(ip, lockflags);
+               } else {
+                       ASSERT(ip->i_gdquot);
+                       gq = xfs_qm_dqhold(ip->i_gdquot);
+               }
+       }
+       if ((flags & XFS_QMOPT_PQUOTA) && XFS_IS_PQUOTA_ON(mp)) {
+               if (xfs_get_projid(ip) != prid) {
+                       xfs_iunlock(ip, lockflags);
+                       error = xfs_qm_dqget(mp, NULL, (xfs_dqid_t)prid,
+                                                XFS_DQ_PROJ,
+                                                XFS_QMOPT_DQALLOC |
+                                                XFS_QMOPT_DOWARN,
+                                                &pq);
+                       if (error) {
+                               ASSERT(error != -ENOENT);
+                               goto error_rele;
+                       }
+                       xfs_dqunlock(pq);
+                       lockflags = XFS_ILOCK_SHARED;
+                       xfs_ilock(ip, lockflags);
+               } else {
+                       ASSERT(ip->i_pdquot);
+                       pq = xfs_qm_dqhold(ip->i_pdquot);
+               }
+       }
+       if (uq)
+               trace_xfs_dquot_dqalloc(ip);
+
+       xfs_iunlock(ip, lockflags);
+       if (O_udqpp)
+               *O_udqpp = uq;
+       else
+               xfs_qm_dqrele(uq);
+       if (O_gdqpp)
+               *O_gdqpp = gq;
+       else
+               xfs_qm_dqrele(gq);
+       if (O_pdqpp)
+               *O_pdqpp = pq;
+       else
+               xfs_qm_dqrele(pq);
+       return 0;
+
+error_rele:
+       xfs_qm_dqrele(gq);
+       xfs_qm_dqrele(uq);
+       return error;
+}
+
+/*
+ * Actually transfer ownership, and do dquot modifications.
+ * These were already reserved.
+ */
+xfs_dquot_t *
+xfs_qm_vop_chown(
+       xfs_trans_t     *tp,
+       xfs_inode_t     *ip,
+       xfs_dquot_t     **IO_olddq,
+       xfs_dquot_t     *newdq)
+{
+       xfs_dquot_t     *prevdq;
+       uint            bfield = XFS_IS_REALTIME_INODE(ip) ?
+                                XFS_TRANS_DQ_RTBCOUNT : XFS_TRANS_DQ_BCOUNT;
+
+
+       ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+       ASSERT(XFS_IS_QUOTA_RUNNING(ip->i_mount));
+
+       /* old dquot */
+       prevdq = *IO_olddq;
+       ASSERT(prevdq);
+       ASSERT(prevdq != newdq);
+
+       xfs_trans_mod_dquot(tp, prevdq, bfield, -(ip->i_d.di_nblocks));
+       xfs_trans_mod_dquot(tp, prevdq, XFS_TRANS_DQ_ICOUNT, -1);
+
+       /* the sparkling new dquot */
+       xfs_trans_mod_dquot(tp, newdq, bfield, ip->i_d.di_nblocks);
+       xfs_trans_mod_dquot(tp, newdq, XFS_TRANS_DQ_ICOUNT, 1);
+
+       /*
+        * Take an extra reference, because the inode is going to keep
+        * this dquot pointer even after the trans_commit.
+        */
+       *IO_olddq = xfs_qm_dqhold(newdq);
+
+       return prevdq;
+}
+
+/*
+ * Quota reservations for setattr(AT_UID|AT_GID|AT_PROJID).
+ */
+int
+xfs_qm_vop_chown_reserve(
+       struct xfs_trans        *tp,
+       struct xfs_inode        *ip,
+       struct xfs_dquot        *udqp,
+       struct xfs_dquot        *gdqp,
+       struct xfs_dquot        *pdqp,
+       uint                    flags)
+{
+       struct xfs_mount        *mp = ip->i_mount;
+       uint                    delblks, blkflags, prjflags = 0;
+       struct xfs_dquot        *udq_unres = NULL;
+       struct xfs_dquot        *gdq_unres = NULL;
+       struct xfs_dquot        *pdq_unres = NULL;
+       struct xfs_dquot        *udq_delblks = NULL;
+       struct xfs_dquot        *gdq_delblks = NULL;
+       struct xfs_dquot        *pdq_delblks = NULL;
+       int                     error;
+
+
+       ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
+       ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+
+       delblks = ip->i_delayed_blks;
+       blkflags = XFS_IS_REALTIME_INODE(ip) ?
+                       XFS_QMOPT_RES_RTBLKS : XFS_QMOPT_RES_REGBLKS;
+
+       if (XFS_IS_UQUOTA_ON(mp) && udqp &&
+           ip->i_d.di_uid != be32_to_cpu(udqp->q_core.d_id)) {
+               udq_delblks = udqp;
+               /*
+                * If there are delayed allocation blocks, then we have to
+                * unreserve those from the old dquot, and add them to the
+                * new dquot.
+                */
+               if (delblks) {
+                       ASSERT(ip->i_udquot);
+                       udq_unres = ip->i_udquot;
+               }
+       }
+       if (XFS_IS_GQUOTA_ON(ip->i_mount) && gdqp &&
+           ip->i_d.di_gid != be32_to_cpu(gdqp->q_core.d_id)) {
+               gdq_delblks = gdqp;
+               if (delblks) {
+                       ASSERT(ip->i_gdquot);
+                       gdq_unres = ip->i_gdquot;
+               }
+       }
+
+       if (XFS_IS_PQUOTA_ON(ip->i_mount) && pdqp &&
+           xfs_get_projid(ip) != be32_to_cpu(pdqp->q_core.d_id)) {
+               prjflags = XFS_QMOPT_ENOSPC;
+               pdq_delblks = pdqp;
+               if (delblks) {
+                       ASSERT(ip->i_pdquot);
+                       pdq_unres = ip->i_pdquot;
+               }
+       }
+
+       error = xfs_trans_reserve_quota_bydquots(tp, ip->i_mount,
+                               udq_delblks, gdq_delblks, pdq_delblks,
+                               ip->i_d.di_nblocks, 1,
+                               flags | blkflags | prjflags);
+       if (error)
+               return error;
+
+       /*
+        * Do the delayed blks reservations/unreservations now. Since, these
+        * are done without the help of a transaction, if a reservation fails
+        * its previous reservations won't be automatically undone by trans
+        * code. So, we have to do it manually here.
+        */
+       if (delblks) {
+               /*
+                * Do the reservations first. Unreservation can't fail.
+                */
+               ASSERT(udq_delblks || gdq_delblks || pdq_delblks);
+               ASSERT(udq_unres || gdq_unres || pdq_unres);
+               error = xfs_trans_reserve_quota_bydquots(NULL, ip->i_mount,
+                           udq_delblks, gdq_delblks, pdq_delblks,
+                           (xfs_qcnt_t)delblks, 0,
+                           flags | blkflags | prjflags);
+               if (error)
+                       return error;
+               xfs_trans_reserve_quota_bydquots(NULL, ip->i_mount,
+                               udq_unres, gdq_unres, pdq_unres,
+                               -((xfs_qcnt_t)delblks), 0, blkflags);
+       }
+
+       return 0;
+}
+
+int
+xfs_qm_vop_rename_dqattach(
+       struct xfs_inode        **i_tab)
+{
+       struct xfs_mount        *mp = i_tab[0]->i_mount;
+       int                     i;
+
+       if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
+               return 0;
+
+       for (i = 0; (i < 4 && i_tab[i]); i++) {
+               struct xfs_inode        *ip = i_tab[i];
+               int                     error;
+
+               /*
+                * Watch out for duplicate entries in the table.
+                */
+               if (i == 0 || ip != i_tab[i-1]) {
+                       if (XFS_NOT_DQATTACHED(mp, ip)) {
+                               error = xfs_qm_dqattach(ip, 0);
+                               if (error)
+                                       return error;
+                       }
+               }
+       }
+       return 0;
+}
+
+void
+xfs_qm_vop_create_dqattach(
+       struct xfs_trans        *tp,
+       struct xfs_inode        *ip,
+       struct xfs_dquot        *udqp,
+       struct xfs_dquot        *gdqp,
+       struct xfs_dquot        *pdqp)
+{
+       struct xfs_mount        *mp = tp->t_mountp;
+
+       if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
+               return;
+
+       ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+       ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+
+       if (udqp && XFS_IS_UQUOTA_ON(mp)) {
+               ASSERT(ip->i_udquot == NULL);
+               ASSERT(ip->i_d.di_uid == be32_to_cpu(udqp->q_core.d_id));
+
+               ip->i_udquot = xfs_qm_dqhold(udqp);
+               xfs_trans_mod_dquot(tp, udqp, XFS_TRANS_DQ_ICOUNT, 1);
+       }
+       if (gdqp && XFS_IS_GQUOTA_ON(mp)) {
+               ASSERT(ip->i_gdquot == NULL);
+               ASSERT(ip->i_d.di_gid == be32_to_cpu(gdqp->q_core.d_id));
+               ip->i_gdquot = xfs_qm_dqhold(gdqp);
+               xfs_trans_mod_dquot(tp, gdqp, XFS_TRANS_DQ_ICOUNT, 1);
+       }
+       if (pdqp && XFS_IS_PQUOTA_ON(mp)) {
+               ASSERT(ip->i_pdquot == NULL);
+               ASSERT(xfs_get_projid(ip) == be32_to_cpu(pdqp->q_core.d_id));
+
+               ip->i_pdquot = xfs_qm_dqhold(pdqp);
+               xfs_trans_mod_dquot(tp, pdqp, XFS_TRANS_DQ_ICOUNT, 1);
+       }
+}
+