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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/xfs/xfs_dquot.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/xfs/xfs_dquot.c')
-rw-r--r--fs/xfs/xfs_dquot.c1395
1 files changed, 1395 insertions, 0 deletions
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
new file mode 100644
index 000000000..8fb90da89
--- /dev/null
+++ b/fs/xfs/xfs_dquot.c
@@ -0,0 +1,1395 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2003 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_shared.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_inode.h"
+#include "xfs_bmap.h"
+#include "xfs_quota.h"
+#include "xfs_trans.h"
+#include "xfs_buf_item.h"
+#include "xfs_trans_space.h"
+#include "xfs_trans_priv.h"
+#include "xfs_qm.h"
+#include "xfs_trace.h"
+#include "xfs_log.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_error.h"
+
+/*
+ * Lock order:
+ *
+ * ip->i_lock
+ * qi->qi_tree_lock
+ * dquot->q_qlock (xfs_dqlock() and friends)
+ * dquot->q_flush (xfs_dqflock() and friends)
+ * qi->qi_lru_lock
+ *
+ * If two dquots need to be locked the order is user before group/project,
+ * otherwise by the lowest id first, see xfs_dqlock2.
+ */
+
+struct kmem_cache *xfs_dqtrx_cache;
+static struct kmem_cache *xfs_dquot_cache;
+
+static struct lock_class_key xfs_dquot_group_class;
+static struct lock_class_key xfs_dquot_project_class;
+
+/*
+ * This is called to free all the memory associated with a dquot
+ */
+void
+xfs_qm_dqdestroy(
+ struct xfs_dquot *dqp)
+{
+ ASSERT(list_empty(&dqp->q_lru));
+
+ kmem_free(dqp->q_logitem.qli_item.li_lv_shadow);
+ mutex_destroy(&dqp->q_qlock);
+
+ XFS_STATS_DEC(dqp->q_mount, xs_qm_dquot);
+ kmem_cache_free(xfs_dquot_cache, dqp);
+}
+
+/*
+ * If default limits are in force, push them into the dquot now.
+ * We overwrite the dquot limits only if they are zero and this
+ * is not the root dquot.
+ */
+void
+xfs_qm_adjust_dqlimits(
+ struct xfs_dquot *dq)
+{
+ struct xfs_mount *mp = dq->q_mount;
+ struct xfs_quotainfo *q = mp->m_quotainfo;
+ struct xfs_def_quota *defq;
+ int prealloc = 0;
+
+ ASSERT(dq->q_id);
+ defq = xfs_get_defquota(q, xfs_dquot_type(dq));
+
+ if (!dq->q_blk.softlimit) {
+ dq->q_blk.softlimit = defq->blk.soft;
+ prealloc = 1;
+ }
+ if (!dq->q_blk.hardlimit) {
+ dq->q_blk.hardlimit = defq->blk.hard;
+ prealloc = 1;
+ }
+ if (!dq->q_ino.softlimit)
+ dq->q_ino.softlimit = defq->ino.soft;
+ if (!dq->q_ino.hardlimit)
+ dq->q_ino.hardlimit = defq->ino.hard;
+ if (!dq->q_rtb.softlimit)
+ dq->q_rtb.softlimit = defq->rtb.soft;
+ if (!dq->q_rtb.hardlimit)
+ dq->q_rtb.hardlimit = defq->rtb.hard;
+
+ if (prealloc)
+ xfs_dquot_set_prealloc_limits(dq);
+}
+
+/* Set the expiration time of a quota's grace period. */
+time64_t
+xfs_dquot_set_timeout(
+ struct xfs_mount *mp,
+ time64_t timeout)
+{
+ struct xfs_quotainfo *qi = mp->m_quotainfo;
+
+ return clamp_t(time64_t, timeout, qi->qi_expiry_min,
+ qi->qi_expiry_max);
+}
+
+/* Set the length of the default grace period. */
+time64_t
+xfs_dquot_set_grace_period(
+ time64_t grace)
+{
+ return clamp_t(time64_t, grace, XFS_DQ_GRACE_MIN, XFS_DQ_GRACE_MAX);
+}
+
+/*
+ * Determine if this quota counter is over either limit and set the quota
+ * timers as appropriate.
+ */
+static inline void
+xfs_qm_adjust_res_timer(
+ struct xfs_mount *mp,
+ struct xfs_dquot_res *res,
+ struct xfs_quota_limits *qlim)
+{
+ ASSERT(res->hardlimit == 0 || res->softlimit <= res->hardlimit);
+
+ if ((res->softlimit && res->count > res->softlimit) ||
+ (res->hardlimit && res->count > res->hardlimit)) {
+ if (res->timer == 0)
+ res->timer = xfs_dquot_set_timeout(mp,
+ ktime_get_real_seconds() + qlim->time);
+ } else {
+ res->timer = 0;
+ }
+}
+
+/*
+ * Check the limits and timers of a dquot and start or reset timers
+ * if necessary.
+ * This gets called even when quota enforcement is OFF, which makes our
+ * life a little less complicated. (We just don't reject any quota
+ * reservations in that case, when enforcement is off).
+ * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
+ * enforcement's off.
+ * In contrast, warnings are a little different in that they don't
+ * 'automatically' get started when limits get exceeded. They do
+ * get reset to zero, however, when we find the count to be under
+ * the soft limit (they are only ever set non-zero via userspace).
+ */
+void
+xfs_qm_adjust_dqtimers(
+ struct xfs_dquot *dq)
+{
+ struct xfs_mount *mp = dq->q_mount;
+ struct xfs_quotainfo *qi = mp->m_quotainfo;
+ struct xfs_def_quota *defq;
+
+ ASSERT(dq->q_id);
+ defq = xfs_get_defquota(qi, xfs_dquot_type(dq));
+
+ xfs_qm_adjust_res_timer(dq->q_mount, &dq->q_blk, &defq->blk);
+ xfs_qm_adjust_res_timer(dq->q_mount, &dq->q_ino, &defq->ino);
+ xfs_qm_adjust_res_timer(dq->q_mount, &dq->q_rtb, &defq->rtb);
+}
+
+/*
+ * initialize a buffer full of dquots and log the whole thing
+ */
+STATIC void
+xfs_qm_init_dquot_blk(
+ struct xfs_trans *tp,
+ struct xfs_mount *mp,
+ xfs_dqid_t id,
+ xfs_dqtype_t type,
+ struct xfs_buf *bp)
+{
+ struct xfs_quotainfo *q = mp->m_quotainfo;
+ struct xfs_dqblk *d;
+ xfs_dqid_t curid;
+ unsigned int qflag;
+ unsigned int blftype;
+ int i;
+
+ ASSERT(tp);
+ ASSERT(xfs_buf_islocked(bp));
+
+ switch (type) {
+ case XFS_DQTYPE_USER:
+ qflag = XFS_UQUOTA_CHKD;
+ blftype = XFS_BLF_UDQUOT_BUF;
+ break;
+ case XFS_DQTYPE_PROJ:
+ qflag = XFS_PQUOTA_CHKD;
+ blftype = XFS_BLF_PDQUOT_BUF;
+ break;
+ case XFS_DQTYPE_GROUP:
+ qflag = XFS_GQUOTA_CHKD;
+ blftype = XFS_BLF_GDQUOT_BUF;
+ break;
+ default:
+ ASSERT(0);
+ return;
+ }
+
+ d = bp->b_addr;
+
+ /*
+ * ID of the first dquot in the block - id's are zero based.
+ */
+ curid = id - (id % q->qi_dqperchunk);
+ memset(d, 0, BBTOB(q->qi_dqchunklen));
+ for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++) {
+ d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
+ d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
+ d->dd_diskdq.d_id = cpu_to_be32(curid);
+ d->dd_diskdq.d_type = type;
+ if (curid > 0 && xfs_has_bigtime(mp))
+ d->dd_diskdq.d_type |= XFS_DQTYPE_BIGTIME;
+ if (xfs_has_crc(mp)) {
+ uuid_copy(&d->dd_uuid, &mp->m_sb.sb_meta_uuid);
+ xfs_update_cksum((char *)d, sizeof(struct xfs_dqblk),
+ XFS_DQUOT_CRC_OFF);
+ }
+ }
+
+ xfs_trans_dquot_buf(tp, bp, blftype);
+
+ /*
+ * quotacheck uses delayed writes to update all the dquots on disk in an
+ * efficient manner instead of logging the individual dquot changes as
+ * they are made. However if we log the buffer allocated here and crash
+ * after quotacheck while the logged initialisation is still in the
+ * active region of the log, log recovery can replay the dquot buffer
+ * initialisation over the top of the checked dquots and corrupt quota
+ * accounting.
+ *
+ * To avoid this problem, quotacheck cannot log the initialised buffer.
+ * We must still dirty the buffer and write it back before the
+ * allocation transaction clears the log. Therefore, mark the buffer as
+ * ordered instead of logging it directly. This is safe for quotacheck
+ * because it detects and repairs allocated but initialized dquot blocks
+ * in the quota inodes.
+ */
+ if (!(mp->m_qflags & qflag))
+ xfs_trans_ordered_buf(tp, bp);
+ else
+ xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
+}
+
+/*
+ * Initialize the dynamic speculative preallocation thresholds. The lo/hi
+ * watermarks correspond to the soft and hard limits by default. If a soft limit
+ * is not specified, we use 95% of the hard limit.
+ */
+void
+xfs_dquot_set_prealloc_limits(struct xfs_dquot *dqp)
+{
+ uint64_t space;
+
+ dqp->q_prealloc_hi_wmark = dqp->q_blk.hardlimit;
+ dqp->q_prealloc_lo_wmark = dqp->q_blk.softlimit;
+ if (!dqp->q_prealloc_lo_wmark) {
+ dqp->q_prealloc_lo_wmark = dqp->q_prealloc_hi_wmark;
+ do_div(dqp->q_prealloc_lo_wmark, 100);
+ dqp->q_prealloc_lo_wmark *= 95;
+ }
+
+ space = dqp->q_prealloc_hi_wmark;
+
+ do_div(space, 100);
+ dqp->q_low_space[XFS_QLOWSP_1_PCNT] = space;
+ dqp->q_low_space[XFS_QLOWSP_3_PCNT] = space * 3;
+ dqp->q_low_space[XFS_QLOWSP_5_PCNT] = space * 5;
+}
+
+/*
+ * Ensure that the given in-core dquot has a buffer on disk backing it, and
+ * return the buffer locked and held. This is called when the bmapi finds a
+ * hole.
+ */
+STATIC int
+xfs_dquot_disk_alloc(
+ struct xfs_dquot *dqp,
+ struct xfs_buf **bpp)
+{
+ struct xfs_bmbt_irec map;
+ struct xfs_trans *tp;
+ struct xfs_mount *mp = dqp->q_mount;
+ struct xfs_buf *bp;
+ xfs_dqtype_t qtype = xfs_dquot_type(dqp);
+ struct xfs_inode *quotip = xfs_quota_inode(mp, qtype);
+ int nmaps = 1;
+ int error;
+
+ trace_xfs_dqalloc(dqp);
+
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc,
+ XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp);
+ if (error)
+ return error;
+
+ xfs_ilock(quotip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, quotip, 0);
+
+ if (!xfs_this_quota_on(dqp->q_mount, qtype)) {
+ /*
+ * Return if this type of quotas is turned off while we didn't
+ * have an inode lock
+ */
+ error = -ESRCH;
+ goto err_cancel;
+ }
+
+ error = xfs_iext_count_may_overflow(quotip, XFS_DATA_FORK,
+ XFS_IEXT_ADD_NOSPLIT_CNT);
+ if (error == -EFBIG)
+ error = xfs_iext_count_upgrade(tp, quotip,
+ XFS_IEXT_ADD_NOSPLIT_CNT);
+ if (error)
+ goto err_cancel;
+
+ /* Create the block mapping. */
+ error = xfs_bmapi_write(tp, quotip, dqp->q_fileoffset,
+ XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA, 0, &map,
+ &nmaps);
+ if (error)
+ goto err_cancel;
+
+ ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
+ ASSERT(nmaps == 1);
+ ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
+ (map.br_startblock != HOLESTARTBLOCK));
+
+ /*
+ * Keep track of the blkno to save a lookup later
+ */
+ dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
+
+ /* now we can just get the buffer (there's nothing to read yet) */
+ error = xfs_trans_get_buf(tp, mp->m_ddev_targp, dqp->q_blkno,
+ mp->m_quotainfo->qi_dqchunklen, 0, &bp);
+ if (error)
+ goto err_cancel;
+ bp->b_ops = &xfs_dquot_buf_ops;
+
+ /*
+ * Make a chunk of dquots out of this buffer and log
+ * the entire thing.
+ */
+ xfs_qm_init_dquot_blk(tp, mp, dqp->q_id, qtype, bp);
+ xfs_buf_set_ref(bp, XFS_DQUOT_REF);
+
+ /*
+ * Hold the buffer and join it to the dfops so that we'll still own
+ * the buffer when we return to the caller. The buffer disposal on
+ * error must be paid attention to very carefully, as it has been
+ * broken since commit efa092f3d4c6 "[XFS] Fixes a bug in the quota
+ * code when allocating a new dquot record" in 2005, and the later
+ * conversion to xfs_defer_ops in commit 310a75a3c6c747 failed to keep
+ * the buffer locked across the _defer_finish call. We can now do
+ * this correctly with xfs_defer_bjoin.
+ *
+ * Above, we allocated a disk block for the dquot information and used
+ * get_buf to initialize the dquot. If the _defer_finish fails, the old
+ * transaction is gone but the new buffer is not joined or held to any
+ * transaction, so we must _buf_relse it.
+ *
+ * If everything succeeds, the caller of this function is returned a
+ * buffer that is locked and held to the transaction. The caller
+ * is responsible for unlocking any buffer passed back, either
+ * manually or by committing the transaction. On error, the buffer is
+ * released and not passed back.
+ *
+ * Keep the quota inode ILOCKed until after the transaction commit to
+ * maintain the atomicity of bmap/rmap updates.
+ */
+ xfs_trans_bhold(tp, bp);
+ error = xfs_trans_commit(tp);
+ xfs_iunlock(quotip, XFS_ILOCK_EXCL);
+ if (error) {
+ xfs_buf_relse(bp);
+ return error;
+ }
+
+ *bpp = bp;
+ return 0;
+
+err_cancel:
+ xfs_trans_cancel(tp);
+ xfs_iunlock(quotip, XFS_ILOCK_EXCL);
+ return error;
+}
+
+/*
+ * Read in the in-core dquot's on-disk metadata and return the buffer.
+ * Returns ENOENT to signal a hole.
+ */
+STATIC int
+xfs_dquot_disk_read(
+ struct xfs_mount *mp,
+ struct xfs_dquot *dqp,
+ struct xfs_buf **bpp)
+{
+ struct xfs_bmbt_irec map;
+ struct xfs_buf *bp;
+ xfs_dqtype_t qtype = xfs_dquot_type(dqp);
+ struct xfs_inode *quotip = xfs_quota_inode(mp, qtype);
+ uint lock_mode;
+ int nmaps = 1;
+ int error;
+
+ lock_mode = xfs_ilock_data_map_shared(quotip);
+ if (!xfs_this_quota_on(mp, qtype)) {
+ /*
+ * Return if this type of quotas is turned off while we
+ * didn't have the quota inode lock.
+ */
+ xfs_iunlock(quotip, lock_mode);
+ return -ESRCH;
+ }
+
+ /*
+ * Find the block map; no allocations yet
+ */
+ error = xfs_bmapi_read(quotip, dqp->q_fileoffset,
+ XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0);
+ xfs_iunlock(quotip, lock_mode);
+ if (error)
+ return error;
+
+ ASSERT(nmaps == 1);
+ ASSERT(map.br_blockcount >= 1);
+ ASSERT(map.br_startblock != DELAYSTARTBLOCK);
+ if (map.br_startblock == HOLESTARTBLOCK)
+ return -ENOENT;
+
+ trace_xfs_dqtobp_read(dqp);
+
+ /*
+ * store the blkno etc so that we don't have to do the
+ * mapping all the time
+ */
+ dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
+
+ error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
+ mp->m_quotainfo->qi_dqchunklen, 0, &bp,
+ &xfs_dquot_buf_ops);
+ if (error) {
+ ASSERT(bp == NULL);
+ return error;
+ }
+
+ ASSERT(xfs_buf_islocked(bp));
+ xfs_buf_set_ref(bp, XFS_DQUOT_REF);
+ *bpp = bp;
+
+ return 0;
+}
+
+/* Allocate and initialize everything we need for an incore dquot. */
+STATIC struct xfs_dquot *
+xfs_dquot_alloc(
+ struct xfs_mount *mp,
+ xfs_dqid_t id,
+ xfs_dqtype_t type)
+{
+ struct xfs_dquot *dqp;
+
+ dqp = kmem_cache_zalloc(xfs_dquot_cache, GFP_KERNEL | __GFP_NOFAIL);
+
+ dqp->q_type = type;
+ dqp->q_id = id;
+ dqp->q_mount = mp;
+ INIT_LIST_HEAD(&dqp->q_lru);
+ mutex_init(&dqp->q_qlock);
+ init_waitqueue_head(&dqp->q_pinwait);
+ dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
+ /*
+ * Offset of dquot in the (fixed sized) dquot chunk.
+ */
+ dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
+ sizeof(struct xfs_dqblk);
+
+ /*
+ * Because we want to use a counting completion, complete
+ * the flush completion once to allow a single access to
+ * the flush completion without blocking.
+ */
+ init_completion(&dqp->q_flush);
+ complete(&dqp->q_flush);
+
+ /*
+ * Make sure group quotas have a different lock class than user
+ * quotas.
+ */
+ switch (type) {
+ case XFS_DQTYPE_USER:
+ /* uses the default lock class */
+ break;
+ case XFS_DQTYPE_GROUP:
+ lockdep_set_class(&dqp->q_qlock, &xfs_dquot_group_class);
+ break;
+ case XFS_DQTYPE_PROJ:
+ lockdep_set_class(&dqp->q_qlock, &xfs_dquot_project_class);
+ break;
+ default:
+ ASSERT(0);
+ break;
+ }
+
+ xfs_qm_dquot_logitem_init(dqp);
+
+ XFS_STATS_INC(mp, xs_qm_dquot);
+ return dqp;
+}
+
+/* Check the ondisk dquot's id and type match what the incore dquot expects. */
+static bool
+xfs_dquot_check_type(
+ struct xfs_dquot *dqp,
+ struct xfs_disk_dquot *ddqp)
+{
+ uint8_t ddqp_type;
+ uint8_t dqp_type;
+
+ ddqp_type = ddqp->d_type & XFS_DQTYPE_REC_MASK;
+ dqp_type = xfs_dquot_type(dqp);
+
+ if (be32_to_cpu(ddqp->d_id) != dqp->q_id)
+ return false;
+
+ /*
+ * V5 filesystems always expect an exact type match. V4 filesystems
+ * expect an exact match for user dquots and for non-root group and
+ * project dquots.
+ */
+ if (xfs_has_crc(dqp->q_mount) ||
+ dqp_type == XFS_DQTYPE_USER || dqp->q_id != 0)
+ return ddqp_type == dqp_type;
+
+ /*
+ * V4 filesystems support either group or project quotas, but not both
+ * at the same time. The non-user quota file can be switched between
+ * group and project quota uses depending on the mount options, which
+ * means that we can encounter the other type when we try to load quota
+ * defaults. Quotacheck will soon reset the entire quota file
+ * (including the root dquot) anyway, but don't log scary corruption
+ * reports to dmesg.
+ */
+ return ddqp_type == XFS_DQTYPE_GROUP || ddqp_type == XFS_DQTYPE_PROJ;
+}
+
+/* Copy the in-core quota fields in from the on-disk buffer. */
+STATIC int
+xfs_dquot_from_disk(
+ struct xfs_dquot *dqp,
+ struct xfs_buf *bp)
+{
+ struct xfs_disk_dquot *ddqp = bp->b_addr + dqp->q_bufoffset;
+
+ /*
+ * Ensure that we got the type and ID we were looking for.
+ * Everything else was checked by the dquot buffer verifier.
+ */
+ if (!xfs_dquot_check_type(dqp, ddqp)) {
+ xfs_alert_tag(bp->b_mount, XFS_PTAG_VERIFIER_ERROR,
+ "Metadata corruption detected at %pS, quota %u",
+ __this_address, dqp->q_id);
+ xfs_alert(bp->b_mount, "Unmount and run xfs_repair");
+ return -EFSCORRUPTED;
+ }
+
+ /* copy everything from disk dquot to the incore dquot */
+ dqp->q_type = ddqp->d_type;
+ dqp->q_blk.hardlimit = be64_to_cpu(ddqp->d_blk_hardlimit);
+ dqp->q_blk.softlimit = be64_to_cpu(ddqp->d_blk_softlimit);
+ dqp->q_ino.hardlimit = be64_to_cpu(ddqp->d_ino_hardlimit);
+ dqp->q_ino.softlimit = be64_to_cpu(ddqp->d_ino_softlimit);
+ dqp->q_rtb.hardlimit = be64_to_cpu(ddqp->d_rtb_hardlimit);
+ dqp->q_rtb.softlimit = be64_to_cpu(ddqp->d_rtb_softlimit);
+
+ dqp->q_blk.count = be64_to_cpu(ddqp->d_bcount);
+ dqp->q_ino.count = be64_to_cpu(ddqp->d_icount);
+ dqp->q_rtb.count = be64_to_cpu(ddqp->d_rtbcount);
+
+ dqp->q_blk.timer = xfs_dquot_from_disk_ts(ddqp, ddqp->d_btimer);
+ dqp->q_ino.timer = xfs_dquot_from_disk_ts(ddqp, ddqp->d_itimer);
+ dqp->q_rtb.timer = xfs_dquot_from_disk_ts(ddqp, ddqp->d_rtbtimer);
+
+ /*
+ * Reservation counters are defined as reservation plus current usage
+ * to avoid having to add every time.
+ */
+ dqp->q_blk.reserved = dqp->q_blk.count;
+ dqp->q_ino.reserved = dqp->q_ino.count;
+ dqp->q_rtb.reserved = dqp->q_rtb.count;
+
+ /* initialize the dquot speculative prealloc thresholds */
+ xfs_dquot_set_prealloc_limits(dqp);
+ return 0;
+}
+
+/* Copy the in-core quota fields into the on-disk buffer. */
+void
+xfs_dquot_to_disk(
+ struct xfs_disk_dquot *ddqp,
+ struct xfs_dquot *dqp)
+{
+ ddqp->d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
+ ddqp->d_version = XFS_DQUOT_VERSION;
+ ddqp->d_type = dqp->q_type;
+ ddqp->d_id = cpu_to_be32(dqp->q_id);
+ ddqp->d_pad0 = 0;
+ ddqp->d_pad = 0;
+
+ ddqp->d_blk_hardlimit = cpu_to_be64(dqp->q_blk.hardlimit);
+ ddqp->d_blk_softlimit = cpu_to_be64(dqp->q_blk.softlimit);
+ ddqp->d_ino_hardlimit = cpu_to_be64(dqp->q_ino.hardlimit);
+ ddqp->d_ino_softlimit = cpu_to_be64(dqp->q_ino.softlimit);
+ ddqp->d_rtb_hardlimit = cpu_to_be64(dqp->q_rtb.hardlimit);
+ ddqp->d_rtb_softlimit = cpu_to_be64(dqp->q_rtb.softlimit);
+
+ ddqp->d_bcount = cpu_to_be64(dqp->q_blk.count);
+ ddqp->d_icount = cpu_to_be64(dqp->q_ino.count);
+ ddqp->d_rtbcount = cpu_to_be64(dqp->q_rtb.count);
+
+ ddqp->d_bwarns = 0;
+ ddqp->d_iwarns = 0;
+ ddqp->d_rtbwarns = 0;
+
+ ddqp->d_btimer = xfs_dquot_to_disk_ts(dqp, dqp->q_blk.timer);
+ ddqp->d_itimer = xfs_dquot_to_disk_ts(dqp, dqp->q_ino.timer);
+ ddqp->d_rtbtimer = xfs_dquot_to_disk_ts(dqp, dqp->q_rtb.timer);
+}
+
+/*
+ * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
+ * and release the buffer immediately. If @can_alloc is true, fill any
+ * holes in the on-disk metadata.
+ */
+static int
+xfs_qm_dqread(
+ struct xfs_mount *mp,
+ xfs_dqid_t id,
+ xfs_dqtype_t type,
+ bool can_alloc,
+ struct xfs_dquot **dqpp)
+{
+ struct xfs_dquot *dqp;
+ struct xfs_buf *bp;
+ int error;
+
+ dqp = xfs_dquot_alloc(mp, id, type);
+ trace_xfs_dqread(dqp);
+
+ /* Try to read the buffer, allocating if necessary. */
+ error = xfs_dquot_disk_read(mp, dqp, &bp);
+ if (error == -ENOENT && can_alloc)
+ error = xfs_dquot_disk_alloc(dqp, &bp);
+ if (error)
+ goto err;
+
+ /*
+ * At this point we should have a clean locked buffer. Copy the data
+ * to the incore dquot and release the buffer since the incore dquot
+ * has its own locking protocol so we needn't tie up the buffer any
+ * further.
+ */
+ ASSERT(xfs_buf_islocked(bp));
+ error = xfs_dquot_from_disk(dqp, bp);
+ xfs_buf_relse(bp);
+ if (error)
+ goto err;
+
+ *dqpp = dqp;
+ return error;
+
+err:
+ trace_xfs_dqread_fail(dqp);
+ xfs_qm_dqdestroy(dqp);
+ *dqpp = NULL;
+ return error;
+}
+
+/*
+ * Advance to the next id in the current chunk, or if at the
+ * end of the chunk, skip ahead to first id in next allocated chunk
+ * using the SEEK_DATA interface.
+ */
+static int
+xfs_dq_get_next_id(
+ struct xfs_mount *mp,
+ xfs_dqtype_t type,
+ xfs_dqid_t *id)
+{
+ struct xfs_inode *quotip = xfs_quota_inode(mp, type);
+ xfs_dqid_t next_id = *id + 1; /* simple advance */
+ uint lock_flags;
+ struct xfs_bmbt_irec got;
+ struct xfs_iext_cursor cur;
+ xfs_fsblock_t start;
+ int error = 0;
+
+ /* If we'd wrap past the max ID, stop */
+ if (next_id < *id)
+ return -ENOENT;
+
+ /* If new ID is within the current chunk, advancing it sufficed */
+ if (next_id % mp->m_quotainfo->qi_dqperchunk) {
+ *id = next_id;
+ return 0;
+ }
+
+ /* Nope, next_id is now past the current chunk, so find the next one */
+ start = (xfs_fsblock_t)next_id / mp->m_quotainfo->qi_dqperchunk;
+
+ lock_flags = xfs_ilock_data_map_shared(quotip);
+ error = xfs_iread_extents(NULL, quotip, XFS_DATA_FORK);
+ if (error)
+ return error;
+
+ if (xfs_iext_lookup_extent(quotip, &quotip->i_df, start, &cur, &got)) {
+ /* contiguous chunk, bump startoff for the id calculation */
+ if (got.br_startoff < start)
+ got.br_startoff = start;
+ *id = got.br_startoff * mp->m_quotainfo->qi_dqperchunk;
+ } else {
+ error = -ENOENT;
+ }
+
+ xfs_iunlock(quotip, lock_flags);
+
+ return error;
+}
+
+/*
+ * Look up the dquot in the in-core cache. If found, the dquot is returned
+ * locked and ready to go.
+ */
+static struct xfs_dquot *
+xfs_qm_dqget_cache_lookup(
+ struct xfs_mount *mp,
+ struct xfs_quotainfo *qi,
+ struct radix_tree_root *tree,
+ xfs_dqid_t id)
+{
+ struct xfs_dquot *dqp;
+
+restart:
+ mutex_lock(&qi->qi_tree_lock);
+ dqp = radix_tree_lookup(tree, id);
+ if (!dqp) {
+ mutex_unlock(&qi->qi_tree_lock);
+ XFS_STATS_INC(mp, xs_qm_dqcachemisses);
+ return NULL;
+ }
+
+ xfs_dqlock(dqp);
+ if (dqp->q_flags & XFS_DQFLAG_FREEING) {
+ xfs_dqunlock(dqp);
+ mutex_unlock(&qi->qi_tree_lock);
+ trace_xfs_dqget_freeing(dqp);
+ delay(1);
+ goto restart;
+ }
+
+ dqp->q_nrefs++;
+ mutex_unlock(&qi->qi_tree_lock);
+
+ trace_xfs_dqget_hit(dqp);
+ XFS_STATS_INC(mp, xs_qm_dqcachehits);
+ return dqp;
+}
+
+/*
+ * Try to insert a new dquot into the in-core cache. If an error occurs the
+ * caller should throw away the dquot and start over. Otherwise, the dquot
+ * is returned locked (and held by the cache) as if there had been a cache
+ * hit.
+ */
+static int
+xfs_qm_dqget_cache_insert(
+ struct xfs_mount *mp,
+ struct xfs_quotainfo *qi,
+ struct radix_tree_root *tree,
+ xfs_dqid_t id,
+ struct xfs_dquot *dqp)
+{
+ int error;
+
+ mutex_lock(&qi->qi_tree_lock);
+ error = radix_tree_insert(tree, id, dqp);
+ if (unlikely(error)) {
+ /* Duplicate found! Caller must try again. */
+ WARN_ON(error != -EEXIST);
+ mutex_unlock(&qi->qi_tree_lock);
+ trace_xfs_dqget_dup(dqp);
+ return error;
+ }
+
+ /* Return a locked dquot to the caller, with a reference taken. */
+ xfs_dqlock(dqp);
+ dqp->q_nrefs = 1;
+
+ qi->qi_dquots++;
+ mutex_unlock(&qi->qi_tree_lock);
+
+ return 0;
+}
+
+/* Check our input parameters. */
+static int
+xfs_qm_dqget_checks(
+ struct xfs_mount *mp,
+ xfs_dqtype_t type)
+{
+ switch (type) {
+ case XFS_DQTYPE_USER:
+ if (!XFS_IS_UQUOTA_ON(mp))
+ return -ESRCH;
+ return 0;
+ case XFS_DQTYPE_GROUP:
+ if (!XFS_IS_GQUOTA_ON(mp))
+ return -ESRCH;
+ return 0;
+ case XFS_DQTYPE_PROJ:
+ if (!XFS_IS_PQUOTA_ON(mp))
+ return -ESRCH;
+ return 0;
+ default:
+ WARN_ON_ONCE(0);
+ return -EINVAL;
+ }
+}
+
+/*
+ * Given the file system, id, and type (UDQUOT/GDQUOT/PDQUOT), return a
+ * locked dquot, doing an allocation (if requested) as needed.
+ */
+int
+xfs_qm_dqget(
+ struct xfs_mount *mp,
+ xfs_dqid_t id,
+ xfs_dqtype_t type,
+ bool can_alloc,
+ struct xfs_dquot **O_dqpp)
+{
+ struct xfs_quotainfo *qi = mp->m_quotainfo;
+ struct radix_tree_root *tree = xfs_dquot_tree(qi, type);
+ struct xfs_dquot *dqp;
+ int error;
+
+ error = xfs_qm_dqget_checks(mp, type);
+ if (error)
+ return error;
+
+restart:
+ dqp = xfs_qm_dqget_cache_lookup(mp, qi, tree, id);
+ if (dqp) {
+ *O_dqpp = dqp;
+ return 0;
+ }
+
+ error = xfs_qm_dqread(mp, id, type, can_alloc, &dqp);
+ if (error)
+ return error;
+
+ error = xfs_qm_dqget_cache_insert(mp, qi, tree, id, dqp);
+ if (error) {
+ /*
+ * Duplicate found. Just throw away the new dquot and start
+ * over.
+ */
+ xfs_qm_dqdestroy(dqp);
+ XFS_STATS_INC(mp, xs_qm_dquot_dups);
+ goto restart;
+ }
+
+ trace_xfs_dqget_miss(dqp);
+ *O_dqpp = dqp;
+ return 0;
+}
+
+/*
+ * Given a dquot id and type, read and initialize a dquot from the on-disk
+ * metadata. This function is only for use during quota initialization so
+ * it ignores the dquot cache assuming that the dquot shrinker isn't set up.
+ * The caller is responsible for _qm_dqdestroy'ing the returned dquot.
+ */
+int
+xfs_qm_dqget_uncached(
+ struct xfs_mount *mp,
+ xfs_dqid_t id,
+ xfs_dqtype_t type,
+ struct xfs_dquot **dqpp)
+{
+ int error;
+
+ error = xfs_qm_dqget_checks(mp, type);
+ if (error)
+ return error;
+
+ return xfs_qm_dqread(mp, id, type, 0, dqpp);
+}
+
+/* Return the quota id for a given inode and type. */
+xfs_dqid_t
+xfs_qm_id_for_quotatype(
+ struct xfs_inode *ip,
+ xfs_dqtype_t type)
+{
+ switch (type) {
+ case XFS_DQTYPE_USER:
+ return i_uid_read(VFS_I(ip));
+ case XFS_DQTYPE_GROUP:
+ return i_gid_read(VFS_I(ip));
+ case XFS_DQTYPE_PROJ:
+ return ip->i_projid;
+ }
+ ASSERT(0);
+ return 0;
+}
+
+/*
+ * Return the dquot for a given inode and type. If @can_alloc is true, then
+ * allocate blocks if needed. The inode's ILOCK must be held and it must not
+ * have already had an inode attached.
+ */
+int
+xfs_qm_dqget_inode(
+ struct xfs_inode *ip,
+ xfs_dqtype_t type,
+ bool can_alloc,
+ struct xfs_dquot **O_dqpp)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_quotainfo *qi = mp->m_quotainfo;
+ struct radix_tree_root *tree = xfs_dquot_tree(qi, type);
+ struct xfs_dquot *dqp;
+ xfs_dqid_t id;
+ int error;
+
+ error = xfs_qm_dqget_checks(mp, type);
+ if (error)
+ return error;
+
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+ ASSERT(xfs_inode_dquot(ip, type) == NULL);
+
+ id = xfs_qm_id_for_quotatype(ip, type);
+
+restart:
+ dqp = xfs_qm_dqget_cache_lookup(mp, qi, tree, id);
+ if (dqp) {
+ *O_dqpp = dqp;
+ return 0;
+ }
+
+ /*
+ * Dquot cache miss. We don't want to keep the inode lock across
+ * a (potential) disk read. Also we don't want to deal with the lock
+ * ordering between quotainode and this inode. OTOH, dropping the inode
+ * lock here means dealing with a chown that can happen before
+ * we re-acquire the lock.
+ */
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ error = xfs_qm_dqread(mp, id, type, can_alloc, &dqp);
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ if (error)
+ return error;
+
+ /*
+ * A dquot could be attached to this inode by now, since we had
+ * dropped the ilock.
+ */
+ if (xfs_this_quota_on(mp, type)) {
+ struct xfs_dquot *dqp1;
+
+ dqp1 = xfs_inode_dquot(ip, type);
+ if (dqp1) {
+ xfs_qm_dqdestroy(dqp);
+ dqp = dqp1;
+ xfs_dqlock(dqp);
+ goto dqret;
+ }
+ } else {
+ /* inode stays locked on return */
+ xfs_qm_dqdestroy(dqp);
+ return -ESRCH;
+ }
+
+ error = xfs_qm_dqget_cache_insert(mp, qi, tree, id, dqp);
+ if (error) {
+ /*
+ * Duplicate found. Just throw away the new dquot and start
+ * over.
+ */
+ xfs_qm_dqdestroy(dqp);
+ XFS_STATS_INC(mp, xs_qm_dquot_dups);
+ goto restart;
+ }
+
+dqret:
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+ trace_xfs_dqget_miss(dqp);
+ *O_dqpp = dqp;
+ return 0;
+}
+
+/*
+ * Starting at @id and progressing upwards, look for an initialized incore
+ * dquot, lock it, and return it.
+ */
+int
+xfs_qm_dqget_next(
+ struct xfs_mount *mp,
+ xfs_dqid_t id,
+ xfs_dqtype_t type,
+ struct xfs_dquot **dqpp)
+{
+ struct xfs_dquot *dqp;
+ int error = 0;
+
+ *dqpp = NULL;
+ for (; !error; error = xfs_dq_get_next_id(mp, type, &id)) {
+ error = xfs_qm_dqget(mp, id, type, false, &dqp);
+ if (error == -ENOENT)
+ continue;
+ else if (error != 0)
+ break;
+
+ if (!XFS_IS_DQUOT_UNINITIALIZED(dqp)) {
+ *dqpp = dqp;
+ return 0;
+ }
+
+ xfs_qm_dqput(dqp);
+ }
+
+ return error;
+}
+
+/*
+ * Release a reference to the dquot (decrement ref-count) and unlock it.
+ *
+ * If there is a group quota attached to this dquot, carefully release that
+ * too without tripping over deadlocks'n'stuff.
+ */
+void
+xfs_qm_dqput(
+ struct xfs_dquot *dqp)
+{
+ ASSERT(dqp->q_nrefs > 0);
+ ASSERT(XFS_DQ_IS_LOCKED(dqp));
+
+ trace_xfs_dqput(dqp);
+
+ if (--dqp->q_nrefs == 0) {
+ struct xfs_quotainfo *qi = dqp->q_mount->m_quotainfo;
+ trace_xfs_dqput_free(dqp);
+
+ if (list_lru_add(&qi->qi_lru, &dqp->q_lru))
+ XFS_STATS_INC(dqp->q_mount, xs_qm_dquot_unused);
+ }
+ xfs_dqunlock(dqp);
+}
+
+/*
+ * Release a dquot. Flush it if dirty, then dqput() it.
+ * dquot must not be locked.
+ */
+void
+xfs_qm_dqrele(
+ struct xfs_dquot *dqp)
+{
+ if (!dqp)
+ return;
+
+ trace_xfs_dqrele(dqp);
+
+ xfs_dqlock(dqp);
+ /*
+ * We don't care to flush it if the dquot is dirty here.
+ * That will create stutters that we want to avoid.
+ * Instead we do a delayed write when we try to reclaim
+ * a dirty dquot. Also xfs_sync will take part of the burden...
+ */
+ xfs_qm_dqput(dqp);
+}
+
+/*
+ * This is the dquot flushing I/O completion routine. It is called
+ * from interrupt level when the buffer containing the dquot is
+ * flushed to disk. It is responsible for removing the dquot logitem
+ * from the AIL if it has not been re-logged, and unlocking the dquot's
+ * flush lock. This behavior is very similar to that of inodes..
+ */
+static void
+xfs_qm_dqflush_done(
+ struct xfs_log_item *lip)
+{
+ struct xfs_dq_logitem *qip = (struct xfs_dq_logitem *)lip;
+ struct xfs_dquot *dqp = qip->qli_dquot;
+ struct xfs_ail *ailp = lip->li_ailp;
+ xfs_lsn_t tail_lsn;
+
+ /*
+ * We only want to pull the item from the AIL if its
+ * location in the log has not changed since we started the flush.
+ * Thus, we only bother if the dquot's lsn has
+ * not changed. First we check the lsn outside the lock
+ * since it's cheaper, and then we recheck while
+ * holding the lock before removing the dquot from the AIL.
+ */
+ if (test_bit(XFS_LI_IN_AIL, &lip->li_flags) &&
+ ((lip->li_lsn == qip->qli_flush_lsn) ||
+ test_bit(XFS_LI_FAILED, &lip->li_flags))) {
+
+ spin_lock(&ailp->ail_lock);
+ xfs_clear_li_failed(lip);
+ if (lip->li_lsn == qip->qli_flush_lsn) {
+ /* xfs_ail_update_finish() drops the AIL lock */
+ tail_lsn = xfs_ail_delete_one(ailp, lip);
+ xfs_ail_update_finish(ailp, tail_lsn);
+ } else {
+ spin_unlock(&ailp->ail_lock);
+ }
+ }
+
+ /*
+ * Release the dq's flush lock since we're done with it.
+ */
+ xfs_dqfunlock(dqp);
+}
+
+void
+xfs_buf_dquot_iodone(
+ struct xfs_buf *bp)
+{
+ struct xfs_log_item *lip, *n;
+
+ list_for_each_entry_safe(lip, n, &bp->b_li_list, li_bio_list) {
+ list_del_init(&lip->li_bio_list);
+ xfs_qm_dqflush_done(lip);
+ }
+}
+
+void
+xfs_buf_dquot_io_fail(
+ struct xfs_buf *bp)
+{
+ struct xfs_log_item *lip;
+
+ spin_lock(&bp->b_mount->m_ail->ail_lock);
+ list_for_each_entry(lip, &bp->b_li_list, li_bio_list)
+ xfs_set_li_failed(lip, bp);
+ spin_unlock(&bp->b_mount->m_ail->ail_lock);
+}
+
+/* Check incore dquot for errors before we flush. */
+static xfs_failaddr_t
+xfs_qm_dqflush_check(
+ struct xfs_dquot *dqp)
+{
+ xfs_dqtype_t type = xfs_dquot_type(dqp);
+
+ if (type != XFS_DQTYPE_USER &&
+ type != XFS_DQTYPE_GROUP &&
+ type != XFS_DQTYPE_PROJ)
+ return __this_address;
+
+ if (dqp->q_id == 0)
+ return NULL;
+
+ if (dqp->q_blk.softlimit && dqp->q_blk.count > dqp->q_blk.softlimit &&
+ !dqp->q_blk.timer)
+ return __this_address;
+
+ if (dqp->q_ino.softlimit && dqp->q_ino.count > dqp->q_ino.softlimit &&
+ !dqp->q_ino.timer)
+ return __this_address;
+
+ if (dqp->q_rtb.softlimit && dqp->q_rtb.count > dqp->q_rtb.softlimit &&
+ !dqp->q_rtb.timer)
+ return __this_address;
+
+ /* bigtime flag should never be set on root dquots */
+ if (dqp->q_type & XFS_DQTYPE_BIGTIME) {
+ if (!xfs_has_bigtime(dqp->q_mount))
+ return __this_address;
+ if (dqp->q_id == 0)
+ return __this_address;
+ }
+
+ return NULL;
+}
+
+/*
+ * Write a modified dquot to disk.
+ * The dquot must be locked and the flush lock too taken by caller.
+ * The flush lock will not be unlocked until the dquot reaches the disk,
+ * but the dquot is free to be unlocked and modified by the caller
+ * in the interim. Dquot is still locked on return. This behavior is
+ * identical to that of inodes.
+ */
+int
+xfs_qm_dqflush(
+ struct xfs_dquot *dqp,
+ struct xfs_buf **bpp)
+{
+ struct xfs_mount *mp = dqp->q_mount;
+ struct xfs_log_item *lip = &dqp->q_logitem.qli_item;
+ struct xfs_buf *bp;
+ struct xfs_dqblk *dqblk;
+ xfs_failaddr_t fa;
+ int error;
+
+ ASSERT(XFS_DQ_IS_LOCKED(dqp));
+ ASSERT(!completion_done(&dqp->q_flush));
+
+ trace_xfs_dqflush(dqp);
+
+ *bpp = NULL;
+
+ xfs_qm_dqunpin_wait(dqp);
+
+ /*
+ * Get the buffer containing the on-disk dquot
+ */
+ error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
+ mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK,
+ &bp, &xfs_dquot_buf_ops);
+ if (error == -EAGAIN)
+ goto out_unlock;
+ if (error)
+ goto out_abort;
+
+ fa = xfs_qm_dqflush_check(dqp);
+ if (fa) {
+ xfs_alert(mp, "corrupt dquot ID 0x%x in memory at %pS",
+ dqp->q_id, fa);
+ xfs_buf_relse(bp);
+ error = -EFSCORRUPTED;
+ goto out_abort;
+ }
+
+ /* Flush the incore dquot to the ondisk buffer. */
+ dqblk = bp->b_addr + dqp->q_bufoffset;
+ xfs_dquot_to_disk(&dqblk->dd_diskdq, dqp);
+
+ /*
+ * Clear the dirty field and remember the flush lsn for later use.
+ */
+ dqp->q_flags &= ~XFS_DQFLAG_DIRTY;
+
+ xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
+ &dqp->q_logitem.qli_item.li_lsn);
+
+ /*
+ * copy the lsn into the on-disk dquot now while we have the in memory
+ * dquot here. This can't be done later in the write verifier as we
+ * can't get access to the log item at that point in time.
+ *
+ * We also calculate the CRC here so that the on-disk dquot in the
+ * buffer always has a valid CRC. This ensures there is no possibility
+ * of a dquot without an up-to-date CRC getting to disk.
+ */
+ if (xfs_has_crc(mp)) {
+ dqblk->dd_lsn = cpu_to_be64(dqp->q_logitem.qli_item.li_lsn);
+ xfs_update_cksum((char *)dqblk, sizeof(struct xfs_dqblk),
+ XFS_DQUOT_CRC_OFF);
+ }
+
+ /*
+ * Attach the dquot to the buffer so that we can remove this dquot from
+ * the AIL and release the flush lock once the dquot is synced to disk.
+ */
+ bp->b_flags |= _XBF_DQUOTS;
+ list_add_tail(&dqp->q_logitem.qli_item.li_bio_list, &bp->b_li_list);
+
+ /*
+ * If the buffer is pinned then push on the log so we won't
+ * get stuck waiting in the write for too long.
+ */
+ if (xfs_buf_ispinned(bp)) {
+ trace_xfs_dqflush_force(dqp);
+ xfs_log_force(mp, 0);
+ }
+
+ trace_xfs_dqflush_done(dqp);
+ *bpp = bp;
+ return 0;
+
+out_abort:
+ dqp->q_flags &= ~XFS_DQFLAG_DIRTY;
+ xfs_trans_ail_delete(lip, 0);
+ xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+out_unlock:
+ xfs_dqfunlock(dqp);
+ return error;
+}
+
+/*
+ * Lock two xfs_dquot structures.
+ *
+ * To avoid deadlocks we always lock the quota structure with
+ * the lowerd id first.
+ */
+void
+xfs_dqlock2(
+ struct xfs_dquot *d1,
+ struct xfs_dquot *d2)
+{
+ if (d1 && d2) {
+ ASSERT(d1 != d2);
+ if (d1->q_id > d2->q_id) {
+ mutex_lock(&d2->q_qlock);
+ mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
+ } else {
+ mutex_lock(&d1->q_qlock);
+ mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
+ }
+ } else if (d1) {
+ mutex_lock(&d1->q_qlock);
+ } else if (d2) {
+ mutex_lock(&d2->q_qlock);
+ }
+}
+
+int __init
+xfs_qm_init(void)
+{
+ xfs_dquot_cache = kmem_cache_create("xfs_dquot",
+ sizeof(struct xfs_dquot),
+ 0, 0, NULL);
+ if (!xfs_dquot_cache)
+ goto out;
+
+ xfs_dqtrx_cache = kmem_cache_create("xfs_dqtrx",
+ sizeof(struct xfs_dquot_acct),
+ 0, 0, NULL);
+ if (!xfs_dqtrx_cache)
+ goto out_free_dquot_cache;
+
+ return 0;
+
+out_free_dquot_cache:
+ kmem_cache_destroy(xfs_dquot_cache);
+out:
+ return -ENOMEM;
+}
+
+void
+xfs_qm_exit(void)
+{
+ kmem_cache_destroy(xfs_dqtrx_cache);
+ kmem_cache_destroy(xfs_dquot_cache);
+}
+
+/*
+ * Iterate every dquot of a particular type. The caller must ensure that the
+ * particular quota type is active. iter_fn can return negative error codes,
+ * or -ECANCELED to indicate that it wants to stop iterating.
+ */
+int
+xfs_qm_dqiterate(
+ struct xfs_mount *mp,
+ xfs_dqtype_t type,
+ xfs_qm_dqiterate_fn iter_fn,
+ void *priv)
+{
+ struct xfs_dquot *dq;
+ xfs_dqid_t id = 0;
+ int error;
+
+ do {
+ error = xfs_qm_dqget_next(mp, id, type, &dq);
+ if (error == -ENOENT)
+ return 0;
+ if (error)
+ return error;
+
+ error = iter_fn(dq, type, priv);
+ id = dq->q_id;
+ xfs_qm_dqput(dq);
+ } while (error == 0 && id != 0);
+
+ return error;
+}