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authorChristoph Hellwig <hch@infradead.org>2011-08-12 16:21:35 -0500
committerAlex Elder <aelder@sgi.com>2011-08-12 16:21:35 -0500
commitc59d87c460767bc35dafd490139d3cfe78fb8da4 (patch)
tree2aad8261f86488e501d9645bd35d1398906da46d /fs/xfs/xfs_dquot.c
parent06f8e2d6754dc631732415b741b5aa58a0f7133f (diff)
xfs: remove subdirectories
Use the move from Linux 2.6 to Linux 3.x as an excuse to kill the annoying subdirectories in the XFS source code. Besides the large amount of file rename the only changes are to the Makefile, a few files including headers with the subdirectory prefix, and the binary sysctl compat code that includes a header under fs/xfs/ from kernel/. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_dquot.c')
-rw-r--r--fs/xfs/xfs_dquot.c1454
1 files changed, 1454 insertions, 0 deletions
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
new file mode 100644
index 00000000000..db62959bed1
--- /dev/null
+++ b/fs/xfs/xfs_dquot.c
@@ -0,0 +1,1454 @@
+/*
+ * Copyright (c) 2000-2003 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_bit.h"
+#include "xfs_log.h"
+#include "xfs_inum.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_alloc.h"
+#include "xfs_quota.h"
+#include "xfs_mount.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_inode.h"
+#include "xfs_bmap.h"
+#include "xfs_rtalloc.h"
+#include "xfs_error.h"
+#include "xfs_itable.h"
+#include "xfs_attr.h"
+#include "xfs_buf_item.h"
+#include "xfs_trans_space.h"
+#include "xfs_trans_priv.h"
+#include "xfs_qm.h"
+#include "xfs_trace.h"
+
+
+/*
+ LOCK ORDER
+
+ inode lock (ilock)
+ dquot hash-chain lock (hashlock)
+ xqm dquot freelist lock (freelistlock
+ mount's dquot list lock (mplistlock)
+ user dquot lock - lock ordering among dquots is based on the uid or gid
+ group dquot lock - similar to udquots. Between the two dquots, the udquot
+ has to be locked first.
+ pin lock - the dquot lock must be held to take this lock.
+ flush lock - ditto.
+*/
+
+#ifdef DEBUG
+xfs_buftarg_t *xfs_dqerror_target;
+int xfs_do_dqerror;
+int xfs_dqreq_num;
+int xfs_dqerror_mod = 33;
+#endif
+
+static struct lock_class_key xfs_dquot_other_class;
+
+/*
+ * Allocate and initialize a dquot. We don't always allocate fresh memory;
+ * we try to reclaim a free dquot if the number of incore dquots are above
+ * a threshold.
+ * The only field inside the core that gets initialized at this point
+ * is the d_id field. The idea is to fill in the entire q_core
+ * when we read in the on disk dquot.
+ */
+STATIC xfs_dquot_t *
+xfs_qm_dqinit(
+ xfs_mount_t *mp,
+ xfs_dqid_t id,
+ uint type)
+{
+ xfs_dquot_t *dqp;
+ boolean_t brandnewdquot;
+
+ brandnewdquot = xfs_qm_dqalloc_incore(&dqp);
+ dqp->dq_flags = type;
+ dqp->q_core.d_id = cpu_to_be32(id);
+ dqp->q_mount = mp;
+
+ /*
+ * No need to re-initialize these if this is a reclaimed dquot.
+ */
+ if (brandnewdquot) {
+ INIT_LIST_HEAD(&dqp->q_freelist);
+ mutex_init(&dqp->q_qlock);
+ init_waitqueue_head(&dqp->q_pinwait);
+
+ /*
+ * 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);
+
+ trace_xfs_dqinit(dqp);
+ } else {
+ /*
+ * Only the q_core portion was zeroed in dqreclaim_one().
+ * So, we need to reset others.
+ */
+ dqp->q_nrefs = 0;
+ dqp->q_blkno = 0;
+ INIT_LIST_HEAD(&dqp->q_mplist);
+ INIT_LIST_HEAD(&dqp->q_hashlist);
+ dqp->q_bufoffset = 0;
+ dqp->q_fileoffset = 0;
+ dqp->q_transp = NULL;
+ dqp->q_gdquot = NULL;
+ dqp->q_res_bcount = 0;
+ dqp->q_res_icount = 0;
+ dqp->q_res_rtbcount = 0;
+ atomic_set(&dqp->q_pincount, 0);
+ dqp->q_hash = NULL;
+ ASSERT(list_empty(&dqp->q_freelist));
+
+ trace_xfs_dqreuse(dqp);
+ }
+
+ /*
+ * In either case we need to make sure group quotas have a different
+ * lock class than user quotas, to make sure lockdep knows we can
+ * locks of one of each at the same time.
+ */
+ if (!(type & XFS_DQ_USER))
+ lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
+
+ /*
+ * log item gets initialized later
+ */
+ return (dqp);
+}
+
+/*
+ * This is called to free all the memory associated with a dquot
+ */
+void
+xfs_qm_dqdestroy(
+ xfs_dquot_t *dqp)
+{
+ ASSERT(list_empty(&dqp->q_freelist));
+
+ mutex_destroy(&dqp->q_qlock);
+ kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);
+
+ atomic_dec(&xfs_Gqm->qm_totaldquots);
+}
+
+/*
+ * This is what a 'fresh' dquot inside a dquot chunk looks like on disk.
+ */
+STATIC void
+xfs_qm_dqinit_core(
+ xfs_dqid_t id,
+ uint type,
+ xfs_dqblk_t *d)
+{
+ /*
+ * Caller has zero'd the entire dquot 'chunk' already.
+ */
+ 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(id);
+ d->dd_diskdq.d_flags = type;
+}
+
+/*
+ * 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(
+ xfs_mount_t *mp,
+ xfs_disk_dquot_t *d)
+{
+ xfs_quotainfo_t *q = mp->m_quotainfo;
+
+ ASSERT(d->d_id);
+
+ if (q->qi_bsoftlimit && !d->d_blk_softlimit)
+ d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
+ if (q->qi_bhardlimit && !d->d_blk_hardlimit)
+ d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
+ if (q->qi_isoftlimit && !d->d_ino_softlimit)
+ d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
+ if (q->qi_ihardlimit && !d->d_ino_hardlimit)
+ d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
+ if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
+ d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
+ if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
+ d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
+}
+
+/*
+ * 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(
+ xfs_mount_t *mp,
+ xfs_disk_dquot_t *d)
+{
+ ASSERT(d->d_id);
+
+#ifdef DEBUG
+ if (d->d_blk_hardlimit)
+ ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
+ be64_to_cpu(d->d_blk_hardlimit));
+ if (d->d_ino_hardlimit)
+ ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
+ be64_to_cpu(d->d_ino_hardlimit));
+ if (d->d_rtb_hardlimit)
+ ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
+ be64_to_cpu(d->d_rtb_hardlimit));
+#endif
+
+ if (!d->d_btimer) {
+ if ((d->d_blk_softlimit &&
+ (be64_to_cpu(d->d_bcount) >=
+ be64_to_cpu(d->d_blk_softlimit))) ||
+ (d->d_blk_hardlimit &&
+ (be64_to_cpu(d->d_bcount) >=
+ be64_to_cpu(d->d_blk_hardlimit)))) {
+ d->d_btimer = cpu_to_be32(get_seconds() +
+ mp->m_quotainfo->qi_btimelimit);
+ } else {
+ d->d_bwarns = 0;
+ }
+ } else {
+ if ((!d->d_blk_softlimit ||
+ (be64_to_cpu(d->d_bcount) <
+ be64_to_cpu(d->d_blk_softlimit))) &&
+ (!d->d_blk_hardlimit ||
+ (be64_to_cpu(d->d_bcount) <
+ be64_to_cpu(d->d_blk_hardlimit)))) {
+ d->d_btimer = 0;
+ }
+ }
+
+ if (!d->d_itimer) {
+ if ((d->d_ino_softlimit &&
+ (be64_to_cpu(d->d_icount) >=
+ be64_to_cpu(d->d_ino_softlimit))) ||
+ (d->d_ino_hardlimit &&
+ (be64_to_cpu(d->d_icount) >=
+ be64_to_cpu(d->d_ino_hardlimit)))) {
+ d->d_itimer = cpu_to_be32(get_seconds() +
+ mp->m_quotainfo->qi_itimelimit);
+ } else {
+ d->d_iwarns = 0;
+ }
+ } else {
+ if ((!d->d_ino_softlimit ||
+ (be64_to_cpu(d->d_icount) <
+ be64_to_cpu(d->d_ino_softlimit))) &&
+ (!d->d_ino_hardlimit ||
+ (be64_to_cpu(d->d_icount) <
+ be64_to_cpu(d->d_ino_hardlimit)))) {
+ d->d_itimer = 0;
+ }
+ }
+
+ if (!d->d_rtbtimer) {
+ if ((d->d_rtb_softlimit &&
+ (be64_to_cpu(d->d_rtbcount) >=
+ be64_to_cpu(d->d_rtb_softlimit))) ||
+ (d->d_rtb_hardlimit &&
+ (be64_to_cpu(d->d_rtbcount) >=
+ be64_to_cpu(d->d_rtb_hardlimit)))) {
+ d->d_rtbtimer = cpu_to_be32(get_seconds() +
+ mp->m_quotainfo->qi_rtbtimelimit);
+ } else {
+ d->d_rtbwarns = 0;
+ }
+ } else {
+ if ((!d->d_rtb_softlimit ||
+ (be64_to_cpu(d->d_rtbcount) <
+ be64_to_cpu(d->d_rtb_softlimit))) &&
+ (!d->d_rtb_hardlimit ||
+ (be64_to_cpu(d->d_rtbcount) <
+ be64_to_cpu(d->d_rtb_hardlimit)))) {
+ d->d_rtbtimer = 0;
+ }
+ }
+}
+
+/*
+ * initialize a buffer full of dquots and log the whole thing
+ */
+STATIC void
+xfs_qm_init_dquot_blk(
+ xfs_trans_t *tp,
+ xfs_mount_t *mp,
+ xfs_dqid_t id,
+ uint type,
+ xfs_buf_t *bp)
+{
+ struct xfs_quotainfo *q = mp->m_quotainfo;
+ xfs_dqblk_t *d;
+ int curid, i;
+
+ ASSERT(tp);
+ ASSERT(xfs_buf_islocked(bp));
+
+ d = bp->b_addr;
+
+ /*
+ * ID of the first dquot in the block - id's are zero based.
+ */
+ curid = id - (id % q->qi_dqperchunk);
+ ASSERT(curid >= 0);
+ memset(d, 0, BBTOB(q->qi_dqchunklen));
+ for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++)
+ xfs_qm_dqinit_core(curid, type, d);
+ xfs_trans_dquot_buf(tp, bp,
+ (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
+ ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
+ XFS_BLF_GDQUOT_BUF)));
+ xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
+}
+
+
+
+/*
+ * Allocate a block and fill it with dquots.
+ * This is called when the bmapi finds a hole.
+ */
+STATIC int
+xfs_qm_dqalloc(
+ xfs_trans_t **tpp,
+ xfs_mount_t *mp,
+ xfs_dquot_t *dqp,
+ xfs_inode_t *quotip,
+ xfs_fileoff_t offset_fsb,
+ xfs_buf_t **O_bpp)
+{
+ xfs_fsblock_t firstblock;
+ xfs_bmap_free_t flist;
+ xfs_bmbt_irec_t map;
+ int nmaps, error, committed;
+ xfs_buf_t *bp;
+ xfs_trans_t *tp = *tpp;
+
+ ASSERT(tp != NULL);
+
+ trace_xfs_dqalloc(dqp);
+
+ /*
+ * Initialize the bmap freelist prior to calling bmapi code.
+ */
+ xfs_bmap_init(&flist, &firstblock);
+ xfs_ilock(quotip, XFS_ILOCK_EXCL);
+ /*
+ * Return if this type of quotas is turned off while we didn't
+ * have an inode lock
+ */
+ if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
+ xfs_iunlock(quotip, XFS_ILOCK_EXCL);
+ return (ESRCH);
+ }
+
+ xfs_trans_ijoin_ref(tp, quotip, XFS_ILOCK_EXCL);
+ nmaps = 1;
+ if ((error = xfs_bmapi(tp, quotip,
+ offset_fsb, XFS_DQUOT_CLUSTER_SIZE_FSB,
+ XFS_BMAPI_METADATA | XFS_BMAPI_WRITE,
+ &firstblock,
+ XFS_QM_DQALLOC_SPACE_RES(mp),
+ &map, &nmaps, &flist))) {
+ goto error0;
+ }
+ 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) */
+ bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
+ dqp->q_blkno,
+ mp->m_quotainfo->qi_dqchunklen,
+ 0);
+ if (!bp || (error = xfs_buf_geterror(bp)))
+ goto error1;
+ /*
+ * Make a chunk of dquots out of this buffer and log
+ * the entire thing.
+ */
+ xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
+ dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
+
+ /*
+ * xfs_bmap_finish() may commit the current transaction and
+ * start a second transaction if the freelist is not empty.
+ *
+ * Since we still want to modify this buffer, we need to
+ * ensure that the buffer is not released on commit of
+ * the first transaction and ensure the buffer is added to the
+ * second transaction.
+ *
+ * If there is only one transaction then don't stop the buffer
+ * from being released when it commits later on.
+ */
+
+ xfs_trans_bhold(tp, bp);
+
+ if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
+ goto error1;
+ }
+
+ if (committed) {
+ tp = *tpp;
+ xfs_trans_bjoin(tp, bp);
+ } else {
+ xfs_trans_bhold_release(tp, bp);
+ }
+
+ *O_bpp = bp;
+ return 0;
+
+ error1:
+ xfs_bmap_cancel(&flist);
+ error0:
+ xfs_iunlock(quotip, XFS_ILOCK_EXCL);
+
+ return (error);
+}
+
+/*
+ * Maps a dquot to the buffer containing its on-disk version.
+ * This returns a ptr to the buffer containing the on-disk dquot
+ * in the bpp param, and a ptr to the on-disk dquot within that buffer
+ */
+STATIC int
+xfs_qm_dqtobp(
+ xfs_trans_t **tpp,
+ xfs_dquot_t *dqp,
+ xfs_disk_dquot_t **O_ddpp,
+ xfs_buf_t **O_bpp,
+ uint flags)
+{
+ xfs_bmbt_irec_t map;
+ int nmaps = 1, error;
+ xfs_buf_t *bp;
+ xfs_inode_t *quotip = XFS_DQ_TO_QIP(dqp);
+ xfs_mount_t *mp = dqp->q_mount;
+ xfs_disk_dquot_t *ddq;
+ xfs_dqid_t id = be32_to_cpu(dqp->q_core.d_id);
+ xfs_trans_t *tp = (tpp ? *tpp : NULL);
+
+ dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
+
+ xfs_ilock(quotip, XFS_ILOCK_SHARED);
+ if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
+ /*
+ * Return if this type of quotas is turned off while we
+ * didn't have the quota inode lock.
+ */
+ xfs_iunlock(quotip, XFS_ILOCK_SHARED);
+ return ESRCH;
+ }
+
+ /*
+ * Find the block map; no allocations yet
+ */
+ error = xfs_bmapi(NULL, quotip, dqp->q_fileoffset,
+ XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
+ NULL, 0, &map, &nmaps, NULL);
+
+ xfs_iunlock(quotip, XFS_ILOCK_SHARED);
+ if (error)
+ return error;
+
+ ASSERT(nmaps == 1);
+ ASSERT(map.br_blockcount == 1);
+
+ /*
+ * Offset of dquot in the (fixed sized) dquot chunk.
+ */
+ dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
+ sizeof(xfs_dqblk_t);
+
+ ASSERT(map.br_startblock != DELAYSTARTBLOCK);
+ if (map.br_startblock == HOLESTARTBLOCK) {
+ /*
+ * We don't allocate unless we're asked to
+ */
+ if (!(flags & XFS_QMOPT_DQALLOC))
+ return ENOENT;
+
+ ASSERT(tp);
+ error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
+ dqp->q_fileoffset, &bp);
+ if (error)
+ return error;
+ tp = *tpp;
+ } else {
+ 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, tp, mp->m_ddev_targp,
+ dqp->q_blkno,
+ mp->m_quotainfo->qi_dqchunklen,
+ 0, &bp);
+ if (error || !bp)
+ return XFS_ERROR(error);
+ }
+
+ ASSERT(xfs_buf_islocked(bp));
+
+ /*
+ * calculate the location of the dquot inside the buffer.
+ */
+ ddq = bp->b_addr + dqp->q_bufoffset;
+
+ /*
+ * A simple sanity check in case we got a corrupted dquot...
+ */
+ error = xfs_qm_dqcheck(mp, ddq, id, dqp->dq_flags & XFS_DQ_ALLTYPES,
+ flags & (XFS_QMOPT_DQREPAIR|XFS_QMOPT_DOWARN),
+ "dqtobp");
+ if (error) {
+ if (!(flags & XFS_QMOPT_DQREPAIR)) {
+ xfs_trans_brelse(tp, bp);
+ return XFS_ERROR(EIO);
+ }
+ }
+
+ *O_bpp = bp;
+ *O_ddpp = ddq;
+
+ return (0);
+}
+
+
+/*
+ * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
+ * and release the buffer immediately.
+ *
+ */
+/* ARGSUSED */
+STATIC int
+xfs_qm_dqread(
+ xfs_trans_t **tpp,
+ xfs_dqid_t id,
+ xfs_dquot_t *dqp, /* dquot to get filled in */
+ uint flags)
+{
+ xfs_disk_dquot_t *ddqp;
+ xfs_buf_t *bp;
+ int error;
+ xfs_trans_t *tp;
+
+ ASSERT(tpp);
+
+ trace_xfs_dqread(dqp);
+
+ /*
+ * get a pointer to the on-disk dquot and the buffer containing it
+ * dqp already knows its own type (GROUP/USER).
+ */
+ if ((error = xfs_qm_dqtobp(tpp, dqp, &ddqp, &bp, flags))) {
+ return (error);
+ }
+ tp = *tpp;
+
+ /* copy everything from disk dquot to the incore dquot */
+ memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
+ ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);
+ xfs_qm_dquot_logitem_init(dqp);
+
+ /*
+ * Reservation counters are defined as reservation plus current usage
+ * to avoid having to add every time.
+ */
+ dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
+ dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
+ dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);
+
+ /* Mark the buf so that this will stay incore a little longer */
+ XFS_BUF_SET_VTYPE_REF(bp, B_FS_DQUOT, XFS_DQUOT_REF);
+
+ /*
+ * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
+ * So we need to release with xfs_trans_brelse().
+ * The strategy here is identical to that of inodes; we lock
+ * the dquot in xfs_qm_dqget() before making it accessible to
+ * others. This is because dquots, like inodes, need a good level of
+ * concurrency, and we don't want to take locks on the entire buffers
+ * for dquot accesses.
+ * Note also that the dquot buffer may even be dirty at this point, if
+ * this particular dquot was repaired. We still aren't afraid to
+ * brelse it because we have the changes incore.
+ */
+ ASSERT(xfs_buf_islocked(bp));
+ xfs_trans_brelse(tp, bp);
+
+ return (error);
+}
+
+
+/*
+ * allocate an incore dquot from the kernel heap,
+ * and fill its core with quota information kept on disk.
+ * If XFS_QMOPT_DQALLOC is set, it'll allocate a dquot on disk
+ * if it wasn't already allocated.
+ */
+STATIC int
+xfs_qm_idtodq(
+ xfs_mount_t *mp,
+ xfs_dqid_t id, /* gid or uid, depending on type */
+ uint type, /* UDQUOT or GDQUOT */
+ uint flags, /* DQALLOC, DQREPAIR */
+ xfs_dquot_t **O_dqpp)/* OUT : incore dquot, not locked */
+{
+ xfs_dquot_t *dqp;
+ int error;
+ xfs_trans_t *tp;
+ int cancelflags=0;
+
+ dqp = xfs_qm_dqinit(mp, id, type);
+ tp = NULL;
+ if (flags & XFS_QMOPT_DQALLOC) {
+ tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
+ error = xfs_trans_reserve(tp, XFS_QM_DQALLOC_SPACE_RES(mp),
+ XFS_WRITE_LOG_RES(mp) +
+ BBTOB(mp->m_quotainfo->qi_dqchunklen) - 1 +
+ 128,
+ 0,
+ XFS_TRANS_PERM_LOG_RES,
+ XFS_WRITE_LOG_COUNT);
+ if (error) {
+ cancelflags = 0;
+ goto error0;
+ }
+ cancelflags = XFS_TRANS_RELEASE_LOG_RES;
+ }
+
+ /*
+ * Read it from disk; xfs_dqread() takes care of
+ * all the necessary initialization of dquot's fields (locks, etc)
+ */
+ if ((error = xfs_qm_dqread(&tp, id, dqp, flags))) {
+ /*
+ * This can happen if quotas got turned off (ESRCH),
+ * or if the dquot didn't exist on disk and we ask to
+ * allocate (ENOENT).
+ */
+ trace_xfs_dqread_fail(dqp);
+ cancelflags |= XFS_TRANS_ABORT;
+ goto error0;
+ }
+ if (tp) {
+ if ((error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES)))
+ goto error1;
+ }
+
+ *O_dqpp = dqp;
+ return (0);
+
+ error0:
+ ASSERT(error);
+ if (tp)
+ xfs_trans_cancel(tp, cancelflags);
+ error1:
+ xfs_qm_dqdestroy(dqp);
+ *O_dqpp = NULL;
+ return (error);
+}
+
+/*
+ * Lookup a dquot in the incore dquot hashtable. We keep two separate
+ * hashtables for user and group dquots; and, these are global tables
+ * inside the XQM, not per-filesystem tables.
+ * The hash chain must be locked by caller, and it is left locked
+ * on return. Returning dquot is locked.
+ */
+STATIC int
+xfs_qm_dqlookup(
+ xfs_mount_t *mp,
+ xfs_dqid_t id,
+ xfs_dqhash_t *qh,
+ xfs_dquot_t **O_dqpp)
+{
+ xfs_dquot_t *dqp;
+ uint flist_locked;
+
+ ASSERT(mutex_is_locked(&qh->qh_lock));
+
+ flist_locked = B_FALSE;
+
+ /*
+ * Traverse the hashchain looking for a match
+ */
+ list_for_each_entry(dqp, &qh->qh_list, q_hashlist) {
+ /*
+ * We already have the hashlock. We don't need the
+ * dqlock to look at the id field of the dquot, since the
+ * id can't be modified without the hashlock anyway.
+ */
+ if (be32_to_cpu(dqp->q_core.d_id) == id && dqp->q_mount == mp) {
+ trace_xfs_dqlookup_found(dqp);
+
+ /*
+ * All in core dquots must be on the dqlist of mp
+ */
+ ASSERT(!list_empty(&dqp->q_mplist));
+
+ xfs_dqlock(dqp);
+ if (dqp->q_nrefs == 0) {
+ ASSERT(!list_empty(&dqp->q_freelist));
+ if (!mutex_trylock(&xfs_Gqm->qm_dqfrlist_lock)) {
+ trace_xfs_dqlookup_want(dqp);
+
+ /*
+ * We may have raced with dqreclaim_one()
+ * (and lost). So, flag that we don't
+ * want the dquot to be reclaimed.
+ */
+ dqp->dq_flags |= XFS_DQ_WANT;
+ xfs_dqunlock(dqp);
+ mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
+ xfs_dqlock(dqp);
+ dqp->dq_flags &= ~(XFS_DQ_WANT);
+ }
+ flist_locked = B_TRUE;
+ }
+
+ /*
+ * id couldn't have changed; we had the hashlock all
+ * along
+ */
+ ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);
+
+ if (flist_locked) {
+ if (dqp->q_nrefs != 0) {
+ mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
+ flist_locked = B_FALSE;
+ } else {
+ /* take it off the freelist */
+ trace_xfs_dqlookup_freelist(dqp);
+ list_del_init(&dqp->q_freelist);
+ xfs_Gqm->qm_dqfrlist_cnt--;
+ }
+ }
+
+ XFS_DQHOLD(dqp);
+
+ if (flist_locked)
+ mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
+ /*
+ * move the dquot to the front of the hashchain
+ */
+ ASSERT(mutex_is_locked(&qh->qh_lock));
+ list_move(&dqp->q_hashlist, &qh->qh_list);
+ trace_xfs_dqlookup_done(dqp);
+ *O_dqpp = dqp;
+ return 0;
+ }
+ }
+
+ *O_dqpp = NULL;
+ ASSERT(mutex_is_locked(&qh->qh_lock));
+ return (1);
+}
+
+/*
+ * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
+ * a locked dquot, doing an allocation (if requested) as needed.
+ * When both an inode and an id are given, the inode's id takes precedence.
+ * That is, if the id changes while we don't hold the ilock inside this
+ * function, the new dquot is returned, not necessarily the one requested
+ * in the id argument.
+ */
+int
+xfs_qm_dqget(
+ xfs_mount_t *mp,
+ xfs_inode_t *ip, /* locked inode (optional) */
+ xfs_dqid_t id, /* uid/projid/gid depending on type */
+ uint type, /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
+ uint flags, /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
+ xfs_dquot_t **O_dqpp) /* OUT : locked incore dquot */
+{
+ xfs_dquot_t *dqp;
+ xfs_dqhash_t *h;
+ uint version;
+ int error;
+
+ ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+ if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
+ (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
+ (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
+ return (ESRCH);
+ }
+ h = XFS_DQ_HASH(mp, id, type);
+
+#ifdef DEBUG
+ if (xfs_do_dqerror) {
+ if ((xfs_dqerror_target == mp->m_ddev_targp) &&
+ (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
+ xfs_debug(mp, "Returning error in dqget");
+ return (EIO);
+ }
+ }
+#endif
+
+ again:
+
+#ifdef DEBUG
+ ASSERT(type == XFS_DQ_USER ||
+ type == XFS_DQ_PROJ ||
+ type == XFS_DQ_GROUP);
+ if (ip) {
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+ if (type == XFS_DQ_USER)
+ ASSERT(ip->i_udquot == NULL);
+ else
+ ASSERT(ip->i_gdquot == NULL);
+ }
+#endif
+ mutex_lock(&h->qh_lock);
+
+ /*
+ * Look in the cache (hashtable).
+ * The chain is kept locked during lookup.
+ */
+ if (xfs_qm_dqlookup(mp, id, h, O_dqpp) == 0) {
+ XQM_STATS_INC(xqmstats.xs_qm_dqcachehits);
+ /*
+ * The dquot was found, moved to the front of the chain,
+ * taken off the freelist if it was on it, and locked
+ * at this point. Just unlock the hashchain and return.
+ */
+ ASSERT(*O_dqpp);
+ ASSERT(XFS_DQ_IS_LOCKED(*O_dqpp));
+ mutex_unlock(&h->qh_lock);
+ trace_xfs_dqget_hit(*O_dqpp);
+ return (0); /* success */
+ }
+ XQM_STATS_INC(xqmstats.xs_qm_dqcachemisses);
+
+ /*
+ * 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.
+ */
+ if (ip)
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ /*
+ * Save the hashchain version stamp, and unlock the chain, so that
+ * we don't keep the lock across a disk read
+ */
+ version = h->qh_version;
+ mutex_unlock(&h->qh_lock);
+
+ /*
+ * Allocate the dquot on the kernel heap, and read the ondisk
+ * portion off the disk. Also, do all the necessary initialization
+ * 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.
+ */
+ if ((error = xfs_qm_idtodq(mp, id, type,
+ flags & (XFS_QMOPT_DQALLOC|XFS_QMOPT_DQREPAIR|
+ XFS_QMOPT_DOWARN),
+ &dqp))) {
+ if (ip)
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ return (error);
+ }
+
+ /*
+ * See if this is mount code calling to look at the overall quota limits
+ * which are stored in the id == 0 user or group's dquot.
+ * Since we may not have done a quotacheck by this point, just return
+ * the dquot without attaching it to any hashtables, lists, etc, or even
+ * taking a reference.
+ * The caller must dqdestroy this once done.
+ */
+ if (flags & XFS_QMOPT_DQSUSER) {
+ ASSERT(id == 0);
+ ASSERT(! ip);
+ goto dqret;
+ }
+
+ /*
+ * Dquot lock comes after hashlock in the lock ordering
+ */
+ if (ip) {
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+
+ /*
+ * A dquot could be attached to this inode by now, since
+ * we had dropped the ilock.
+ */
+ if (type == XFS_DQ_USER) {
+ if (!XFS_IS_UQUOTA_ON(mp)) {
+ /* inode stays locked on return */
+ xfs_qm_dqdestroy(dqp);
+ return XFS_ERROR(ESRCH);
+ }
+ if (ip->i_udquot) {
+ xfs_qm_dqdestroy(dqp);
+ dqp = ip->i_udquot;
+ xfs_dqlock(dqp);
+ goto dqret;
+ }
+ } else {
+ if (!XFS_IS_OQUOTA_ON(mp)) {
+ /* inode stays locked on return */
+ xfs_qm_dqdestroy(dqp);
+ return XFS_ERROR(ESRCH);
+ }
+ if (ip->i_gdquot) {
+ xfs_qm_dqdestroy(dqp);
+ dqp = ip->i_gdquot;
+ xfs_dqlock(dqp);
+ goto dqret;
+ }
+ }
+ }
+
+ /*
+ * Hashlock comes after ilock in lock order
+ */
+ mutex_lock(&h->qh_lock);
+ if (version != h->qh_version) {
+ xfs_dquot_t *tmpdqp;
+ /*
+ * Now, see if somebody else put the dquot in the
+ * hashtable before us. This can happen because we didn't
+ * keep the hashchain lock. We don't have to worry about
+ * lock order between the two dquots here since dqp isn't
+ * on any findable lists yet.
+ */
+ if (xfs_qm_dqlookup(mp, id, h, &tmpdqp) == 0) {
+ /*
+ * Duplicate found. Just throw away the new dquot
+ * and start over.
+ */
+ xfs_qm_dqput(tmpdqp);
+ mutex_unlock(&h->qh_lock);
+ xfs_qm_dqdestroy(dqp);
+ XQM_STATS_INC(xqmstats.xs_qm_dquot_dups);
+ goto again;
+ }
+ }
+
+ /*
+ * Put the dquot at the beginning of the hash-chain and mp's list
+ * LOCK ORDER: hashlock, freelistlock, mplistlock, udqlock, gdqlock ..
+ */
+ ASSERT(mutex_is_locked(&h->qh_lock));
+ dqp->q_hash = h;
+ list_add(&dqp->q_hashlist, &h->qh_list);
+ h->qh_version++;
+
+ /*
+ * Attach this dquot to this filesystem's list of all dquots,
+ * kept inside the mount structure in m_quotainfo field
+ */
+ mutex_lock(&mp->m_quotainfo->qi_dqlist_lock);
+
+ /*
+ * We return a locked dquot to the caller, with a reference taken
+ */
+ xfs_dqlock(dqp);
+ dqp->q_nrefs = 1;
+
+ list_add(&dqp->q_mplist, &mp->m_quotainfo->qi_dqlist);
+ mp->m_quotainfo->qi_dquots++;
+ mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
+ mutex_unlock(&h->qh_lock);
+ dqret:
+ ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
+ trace_xfs_dqget_miss(dqp);
+ *O_dqpp = dqp;
+ return (0);
+}
+
+
+/*
+ * 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(
+ xfs_dquot_t *dqp)
+{
+ xfs_dquot_t *gdqp;
+
+ ASSERT(dqp->q_nrefs > 0);
+ ASSERT(XFS_DQ_IS_LOCKED(dqp));
+
+ trace_xfs_dqput(dqp);
+
+ if (dqp->q_nrefs != 1) {
+ dqp->q_nrefs--;
+ xfs_dqunlock(dqp);
+ return;
+ }
+
+ /*
+ * drop the dqlock and acquire the freelist and dqlock
+ * in the right order; but try to get it out-of-order first
+ */
+ if (!mutex_trylock(&xfs_Gqm->qm_dqfrlist_lock)) {
+ trace_xfs_dqput_wait(dqp);
+ xfs_dqunlock(dqp);
+ mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
+ xfs_dqlock(dqp);
+ }
+
+ while (1) {
+ gdqp = NULL;
+
+ /* We can't depend on nrefs being == 1 here */
+ if (--dqp->q_nrefs == 0) {
+ trace_xfs_dqput_free(dqp);
+
+ list_add_tail(&dqp->q_freelist, &xfs_Gqm->qm_dqfrlist);
+ xfs_Gqm->qm_dqfrlist_cnt++;
+
+ /*
+ * If we just added a udquot to the freelist, then
+ * we want to release the gdquot reference that
+ * it (probably) has. Otherwise it'll keep the
+ * gdquot from getting reclaimed.
+ */
+ if ((gdqp = dqp->q_gdquot)) {
+ /*
+ * Avoid a recursive dqput call
+ */
+ xfs_dqlock(gdqp);
+ dqp->q_gdquot = NULL;
+ }
+ }
+ xfs_dqunlock(dqp);
+
+ /*
+ * If we had a group quota inside the user quota as a hint,
+ * release it now.
+ */
+ if (! gdqp)
+ break;
+ dqp = gdqp;
+ }
+ mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
+}
+
+/*
+ * Release a dquot. Flush it if dirty, then dqput() it.
+ * dquot must not be locked.
+ */
+void
+xfs_qm_dqrele(
+ xfs_dquot_t *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_buf *bp,
+ struct xfs_log_item *lip)
+{
+ xfs_dq_logitem_t *qip = (struct xfs_dq_logitem *)lip;
+ xfs_dquot_t *dqp = qip->qli_dquot;
+ struct xfs_ail *ailp = lip->li_ailp;
+
+ /*
+ * 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 ((lip->li_flags & XFS_LI_IN_AIL) &&
+ lip->li_lsn == qip->qli_flush_lsn) {
+
+ /* xfs_trans_ail_delete() drops the AIL lock. */
+ spin_lock(&ailp->xa_lock);
+ if (lip->li_lsn == qip->qli_flush_lsn)
+ xfs_trans_ail_delete(ailp, lip);
+ else
+ spin_unlock(&ailp->xa_lock);
+ }
+
+ /*
+ * Release the dq's flush lock since we're done with it.
+ */
+ xfs_dqfunlock(dqp);
+}
+
+/*
+ * 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(
+ xfs_dquot_t *dqp,
+ uint flags)
+{
+ struct xfs_mount *mp = dqp->q_mount;
+ struct xfs_buf *bp;
+ struct xfs_disk_dquot *ddqp;
+ int error;
+
+ ASSERT(XFS_DQ_IS_LOCKED(dqp));
+ ASSERT(!completion_done(&dqp->q_flush));
+
+ trace_xfs_dqflush(dqp);
+
+ /*
+ * If not dirty, or it's pinned and we are not supposed to block, nada.
+ */
+ if (!XFS_DQ_IS_DIRTY(dqp) ||
+ (!(flags & SYNC_WAIT) && atomic_read(&dqp->q_pincount) > 0)) {
+ xfs_dqfunlock(dqp);
+ return 0;
+ }
+ xfs_qm_dqunpin_wait(dqp);
+
+ /*
+ * This may have been unpinned because the filesystem is shutting
+ * down forcibly. If that's the case we must not write this dquot
+ * to disk, because the log record didn't make it to disk!
+ */
+ if (XFS_FORCED_SHUTDOWN(mp)) {
+ dqp->dq_flags &= ~XFS_DQ_DIRTY;
+ xfs_dqfunlock(dqp);
+ return XFS_ERROR(EIO);
+ }
+
+ /*
+ * 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, 0, &bp);
+ if (error) {
+ ASSERT(error != ENOENT);
+ xfs_dqfunlock(dqp);
+ return error;
+ }
+
+ /*
+ * Calculate the location of the dquot inside the buffer.
+ */
+ ddqp = bp->b_addr + dqp->q_bufoffset;
+
+ /*
+ * A simple sanity check in case we got a corrupted dquot..
+ */
+ error = xfs_qm_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
+ XFS_QMOPT_DOWARN, "dqflush (incore copy)");
+ if (error) {
+ xfs_buf_relse(bp);
+ xfs_dqfunlock(dqp);
+ xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+ return XFS_ERROR(EIO);
+ }
+
+ /* This is the only portion of data that needs to persist */
+ memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
+
+ /*
+ * Clear the dirty field and remember the flush lsn for later use.
+ */
+ dqp->dq_flags &= ~XFS_DQ_DIRTY;
+
+ xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
+ &dqp->q_logitem.qli_item.li_lsn);
+
+ /*
+ * Attach an iodone routine so that we can remove this dquot from the
+ * AIL and release the flush lock once the dquot is synced to disk.
+ */
+ xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
+ &dqp->q_logitem.qli_item);
+
+ /*
+ * 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);
+ }
+
+ if (flags & SYNC_WAIT)
+ error = xfs_bwrite(mp, bp);
+ else
+ xfs_bdwrite(mp, bp);
+
+ trace_xfs_dqflush_done(dqp);
+
+ /*
+ * dqp is still locked, but caller is free to unlock it now.
+ */
+ return error;
+
+}
+
+int
+xfs_qm_dqlock_nowait(
+ xfs_dquot_t *dqp)
+{
+ return mutex_trylock(&dqp->q_qlock);
+}
+
+void
+xfs_dqlock(
+ xfs_dquot_t *dqp)
+{
+ mutex_lock(&dqp->q_qlock);
+}
+
+void
+xfs_dqunlock(
+ xfs_dquot_t *dqp)
+{
+ mutex_unlock(&(dqp->q_qlock));
+ if (dqp->q_logitem.qli_dquot == dqp) {
+ /* Once was dqp->q_mount, but might just have been cleared */
+ xfs_trans_unlocked_item(dqp->q_logitem.qli_item.li_ailp,
+ (xfs_log_item_t*)&(dqp->q_logitem));
+ }
+}
+
+
+void
+xfs_dqunlock_nonotify(
+ xfs_dquot_t *dqp)
+{
+ mutex_unlock(&(dqp->q_qlock));
+}
+
+/*
+ * Lock two xfs_dquot structures.
+ *
+ * To avoid deadlocks we always lock the quota structure with
+ * the lowerd id first.
+ */
+void
+xfs_dqlock2(
+ xfs_dquot_t *d1,
+ xfs_dquot_t *d2)
+{
+ if (d1 && d2) {
+ ASSERT(d1 != d2);
+ if (be32_to_cpu(d1->q_core.d_id) >
+ be32_to_cpu(d2->q_core.d_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);
+ }
+}
+
+
+/*
+ * Take a dquot out of the mount's dqlist as well as the hashlist.
+ * This is called via unmount as well as quotaoff, and the purge
+ * will always succeed unless there are soft (temp) references
+ * outstanding.
+ *
+ * This returns 0 if it was purged, 1 if it wasn't. It's not an error code
+ * that we're returning! XXXsup - not cool.
+ */
+/* ARGSUSED */
+int
+xfs_qm_dqpurge(
+ xfs_dquot_t *dqp)
+{
+ xfs_dqhash_t *qh = dqp->q_hash;
+ xfs_mount_t *mp = dqp->q_mount;
+
+ ASSERT(mutex_is_locked(&mp->m_quotainfo->qi_dqlist_lock));
+ ASSERT(mutex_is_locked(&dqp->q_hash->qh_lock));
+
+ xfs_dqlock(dqp);
+ /*
+ * We really can't afford to purge a dquot that is
+ * referenced, because these are hard refs.
+ * It shouldn't happen in general because we went thru _all_ inodes in
+ * dqrele_all_inodes before calling this and didn't let the mountlock go.
+ * However it is possible that we have dquots with temporary
+ * references that are not attached to an inode. e.g. see xfs_setattr().
+ */
+ if (dqp->q_nrefs != 0) {
+ xfs_dqunlock(dqp);
+ mutex_unlock(&dqp->q_hash->qh_lock);
+ return (1);
+ }
+
+ ASSERT(!list_empty(&dqp->q_freelist));
+
+ /*
+ * If we're turning off quotas, we have to make sure that, for
+ * example, we don't delete quota disk blocks while dquots are
+ * in the process of getting written to those disk blocks.
+ * This dquot might well be on AIL, and we can't leave it there
+ * if we're turning off quotas. Basically, we need this flush
+ * lock, and are willing to block on it.
+ */
+ if (!xfs_dqflock_nowait(dqp)) {
+ /*
+ * Block on the flush lock after nudging dquot buffer,
+ * if it is incore.
+ */
+ xfs_qm_dqflock_pushbuf_wait(dqp);
+ }
+
+ /*
+ * XXXIf we're 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)) {
+ int error;
+
+ /* dqflush unlocks dqflock */
+ /*
+ * Given that dqpurge is a very rare occurrence, it is OK
+ * that we're holding the hashlist and mplist locks
+ * across the disk write. But, ... XXXsup
+ *
+ * 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, SYNC_WAIT);
+ if (error)
+ xfs_warn(mp, "%s: dquot %p flush failed",
+ __func__, dqp);
+ 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));
+
+ list_del_init(&dqp->q_hashlist);
+ qh->qh_version++;
+ list_del_init(&dqp->q_mplist);
+ mp->m_quotainfo->qi_dqreclaims++;
+ mp->m_quotainfo->qi_dquots--;
+ /*
+ * XXX Move this to the front of the freelist, if we can get the
+ * freelist lock.
+ */
+ ASSERT(!list_empty(&dqp->q_freelist));
+
+ dqp->q_mount = NULL;
+ dqp->q_hash = NULL;
+ dqp->dq_flags = XFS_DQ_INACTIVE;
+ memset(&dqp->q_core, 0, sizeof(dqp->q_core));
+ xfs_dqfunlock(dqp);
+ xfs_dqunlock(dqp);
+ mutex_unlock(&qh->qh_lock);
+ return (0);
+}
+
+
+/*
+ * Give the buffer a little push if it is incore and
+ * wait on the flush lock.
+ */
+void
+xfs_qm_dqflock_pushbuf_wait(
+ xfs_dquot_t *dqp)
+{
+ xfs_mount_t *mp = dqp->q_mount;
+ xfs_buf_t *bp;
+
+ /*
+ * Check to see if the dquot has been flushed delayed
+ * write. If so, grab its buffer and send it
+ * out immediately. We'll be able to acquire
+ * the flush lock when the I/O completes.
+ */
+ bp = xfs_incore(mp->m_ddev_targp, dqp->q_blkno,
+ mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK);
+ if (!bp)
+ goto out_lock;
+
+ if (XFS_BUF_ISDELAYWRITE(bp)) {
+ if (xfs_buf_ispinned(bp))
+ xfs_log_force(mp, 0);
+ xfs_buf_delwri_promote(bp);
+ wake_up_process(bp->b_target->bt_task);
+ }
+ xfs_buf_relse(bp);
+out_lock:
+ xfs_dqflock(dqp);
+}