v4.19.13 snapshot.
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
new file mode 100644
index 0000000..87e6dd5
--- /dev/null
+++ b/fs/xfs/xfs_dquot.c
@@ -0,0 +1,1272 @@
+// 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_bmap_util.h"
+#include "xfs_alloc.h"
+#include "xfs_quota.h"
+#include "xfs_error.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_cksum.h"
+#include "xfs_trace.h"
+#include "xfs_log.h"
+#include "xfs_bmap_btree.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_zone *xfs_qm_dqtrxzone;
+static struct kmem_zone *xfs_qm_dqzone;
+
+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(
+ xfs_dquot_t *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_zone_free(xfs_qm_dqzone, 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_mount *mp,
+ struct xfs_dquot *dq)
+{
+ struct xfs_quotainfo *q = mp->m_quotainfo;
+ struct xfs_disk_dquot *d = &dq->q_core;
+ struct xfs_def_quota *defq;
+ int prealloc = 0;
+
+ ASSERT(d->d_id);
+ defq = xfs_get_defquota(dq, q);
+
+ if (defq->bsoftlimit && !d->d_blk_softlimit) {
+ d->d_blk_softlimit = cpu_to_be64(defq->bsoftlimit);
+ prealloc = 1;
+ }
+ if (defq->bhardlimit && !d->d_blk_hardlimit) {
+ d->d_blk_hardlimit = cpu_to_be64(defq->bhardlimit);
+ prealloc = 1;
+ }
+ if (defq->isoftlimit && !d->d_ino_softlimit)
+ d->d_ino_softlimit = cpu_to_be64(defq->isoftlimit);
+ if (defq->ihardlimit && !d->d_ino_hardlimit)
+ d->d_ino_hardlimit = cpu_to_be64(defq->ihardlimit);
+ if (defq->rtbsoftlimit && !d->d_rtb_softlimit)
+ d->d_rtb_softlimit = cpu_to_be64(defq->rtbsoftlimit);
+ if (defq->rtbhardlimit && !d->d_rtb_hardlimit)
+ d->d_rtb_hardlimit = cpu_to_be64(defq->rtbhardlimit);
+
+ if (prealloc)
+ xfs_dquot_set_prealloc_limits(dq);
+}
+
+/*
+ * 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;
+ xfs_dqid_t curid;
+ int 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);
+ 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_flags = type;
+ if (xfs_sb_version_hascrc(&mp->m_sb)) {
+ 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,
+ (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);
+}
+
+/*
+ * 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 = be64_to_cpu(dqp->q_core.d_blk_hardlimit);
+ dqp->q_prealloc_lo_wmark = be64_to_cpu(dqp->q_core.d_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. This is called when the bmapi finds a hole.
+ */
+STATIC int
+xfs_dquot_disk_alloc(
+ struct xfs_trans **tpp,
+ struct xfs_dquot *dqp,
+ struct xfs_buf **bpp)
+{
+ struct xfs_bmbt_irec map;
+ struct xfs_trans *tp = *tpp;
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_buf *bp;
+ struct xfs_inode *quotip = xfs_quota_inode(mp, dqp->dq_flags);
+ int nmaps = 1;
+ int error;
+
+ trace_xfs_dqalloc(dqp);
+
+ xfs_ilock(quotip, XFS_ILOCK_EXCL);
+ if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
+ /*
+ * Return if this type of quotas is turned off while we didn't
+ * have an inode lock
+ */
+ xfs_iunlock(quotip, XFS_ILOCK_EXCL);
+ return -ESRCH;
+ }
+
+ /* Create the block mapping. */
+ xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL);
+ error = xfs_bmapi_write(tp, quotip, dqp->q_fileoffset,
+ XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
+ XFS_QM_DQALLOC_SPACE_RES(mp), &map, &nmaps);
+ if (error)
+ return error;
+ 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)
+ return -ENOMEM;
+ 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, be32_to_cpu(dqp->q_core.d_id),
+ dqp->dq_flags & XFS_DQ_ALLTYPES, 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.
+ */
+ xfs_trans_bhold(tp, bp);
+ error = xfs_defer_finish(tpp);
+ tp = *tpp;
+ if (error) {
+ xfs_buf_relse(bp);
+ return error;
+ }
+ *bpp = bp;
+ return 0;
+}
+
+/*
+ * 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;
+ struct xfs_inode *quotip = xfs_quota_inode(mp, dqp->dq_flags);
+ uint lock_mode;
+ int nmaps = 1;
+ int error;
+
+ lock_mode = xfs_ilock_data_map_shared(quotip);
+ if (!xfs_this_quota_on(mp, dqp->dq_flags)) {
+ /*
+ * 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,
+ uint type)
+{
+ struct xfs_dquot *dqp;
+
+ dqp = kmem_zone_zalloc(xfs_qm_dqzone, KM_SLEEP);
+
+ dqp->dq_flags = type;
+ dqp->q_core.d_id = cpu_to_be32(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(xfs_dqblk_t);
+
+ /*
+ * 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_DQ_USER:
+ /* uses the default lock class */
+ break;
+ case XFS_DQ_GROUP:
+ lockdep_set_class(&dqp->q_qlock, &xfs_dquot_group_class);
+ break;
+ case XFS_DQ_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;
+}
+
+/* Copy the in-core quota fields in from the on-disk buffer. */
+STATIC void
+xfs_dquot_from_disk(
+ struct xfs_dquot *dqp,
+ struct xfs_buf *bp)
+{
+ struct xfs_disk_dquot *ddqp = bp->b_addr + dqp->q_bufoffset;
+
+ /* copy everything from disk dquot to the incore dquot */
+ memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
+
+ /*
+ * 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);
+
+ /* initialize the dquot speculative prealloc thresholds */
+ xfs_dquot_set_prealloc_limits(dqp);
+}
+
+/* Allocate and initialize the dquot buffer for this in-core dquot. */
+static int
+xfs_qm_dqread_alloc(
+ struct xfs_mount *mp,
+ struct xfs_dquot *dqp,
+ struct xfs_buf **bpp)
+{
+ struct xfs_trans *tp;
+ struct xfs_buf *bp;
+ int error;
+
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc,
+ XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp);
+ if (error)
+ goto err;
+
+ error = xfs_dquot_disk_alloc(&tp, dqp, &bp);
+ if (error)
+ goto err_cancel;
+
+ error = xfs_trans_commit(tp);
+ if (error) {
+ /*
+ * Buffer was held to the transaction, so we have to unlock it
+ * manually here because we're not passing it back.
+ */
+ xfs_buf_relse(bp);
+ goto err;
+ }
+ *bpp = bp;
+ return 0;
+
+err_cancel:
+ xfs_trans_cancel(tp);
+err:
+ return error;
+}
+
+/*
+ * 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,
+ uint 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_qm_dqread_alloc(mp, 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));
+ xfs_dquot_from_disk(dqp, bp);
+
+ xfs_buf_relse(bp);
+ *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,
+ uint 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);
+ if (!(quotip->i_df.if_flags & XFS_IFEXTENTS)) {
+ error = xfs_iread_extents(NULL, quotip, XFS_DATA_FORK);
+ if (error)
+ return error;
+ }
+
+ if (xfs_iext_lookup_extent(quotip, "ip->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->dq_flags & XFS_DQ_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,
+ uint type)
+{
+ if (WARN_ON_ONCE(!XFS_IS_QUOTA_RUNNING(mp)))
+ return -ESRCH;
+
+ switch (type) {
+ case XFS_DQ_USER:
+ if (!XFS_IS_UQUOTA_ON(mp))
+ return -ESRCH;
+ return 0;
+ case XFS_DQ_GROUP:
+ if (!XFS_IS_GQUOTA_ON(mp))
+ return -ESRCH;
+ return 0;
+ case XFS_DQ_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), return a a locked
+ * dquot, doing an allocation (if requested) as needed.
+ */
+int
+xfs_qm_dqget(
+ struct xfs_mount *mp,
+ xfs_dqid_t id,
+ uint 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,
+ uint 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,
+ uint type)
+{
+ switch (type) {
+ case XFS_DQ_USER:
+ return ip->i_d.di_uid;
+ case XFS_DQ_GROUP:
+ return ip->i_d.di_gid;
+ case XFS_DQ_PROJ:
+ return xfs_get_projid(ip);
+ }
+ 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,
+ uint 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,
+ uint 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(
+ 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 (test_bit(XFS_LI_IN_AIL, &lip->li_flags) &&
+ ((lip->li_lsn == qip->qli_flush_lsn) ||
+ test_bit(XFS_LI_FAILED, &lip->li_flags))) {
+
+ /* xfs_trans_ail_delete() drops the AIL lock. */
+ spin_lock(&ailp->ail_lock);
+ if (lip->li_lsn == qip->qli_flush_lsn) {
+ xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE);
+ } else {
+ /*
+ * Clear the failed state since we are about to drop the
+ * flush lock
+ */
+ xfs_clear_li_failed(lip);
+ spin_unlock(&ailp->ail_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(
+ struct xfs_dquot *dqp,
+ struct xfs_buf **bpp)
+{
+ struct xfs_mount *mp = dqp->q_mount;
+ struct xfs_buf *bp;
+ struct xfs_dqblk *dqb;
+ struct xfs_disk_dquot *ddqp;
+ 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);
+
+ /*
+ * 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.
+ *
+ * We also have to remove the log item from the AIL in this case,
+ * as we wait for an emptry AIL as part of the unmount process.
+ */
+ if (XFS_FORCED_SHUTDOWN(mp)) {
+ struct xfs_log_item *lip = &dqp->q_logitem.qli_item;
+ dqp->dq_flags &= ~XFS_DQ_DIRTY;
+
+ xfs_trans_ail_remove(lip, SHUTDOWN_CORRUPT_INCORE);
+
+ error = -EIO;
+ goto out_unlock;
+ }
+
+ /*
+ * 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,
+ &xfs_dquot_buf_ops);
+ if (error)
+ goto out_unlock;
+
+ /*
+ * Calculate the location of the dquot inside the buffer.
+ */
+ dqb = bp->b_addr + dqp->q_bufoffset;
+ ddqp = &dqb->dd_diskdq;
+
+ /*
+ * A simple sanity check in case we got a corrupted dquot.
+ */
+ fa = xfs_dqblk_verify(mp, dqb, be32_to_cpu(ddqp->d_id), 0);
+ if (fa) {
+ xfs_alert(mp, "corrupt dquot ID 0x%x in memory at %pS",
+ be32_to_cpu(ddqp->d_id), fa);
+ xfs_buf_relse(bp);
+ xfs_dqfunlock(dqp);
+ xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+ return -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);
+
+ /*
+ * 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_sb_version_hascrc(&mp->m_sb)) {
+ dqb->dd_lsn = cpu_to_be64(dqp->q_logitem.qli_item.li_lsn);
+ xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
+ XFS_DQUOT_CRC_OFF);
+ }
+
+ /*
+ * 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);
+ }
+
+ trace_xfs_dqflush_done(dqp);
+ *bpp = bp;
+ return 0;
+
+out_unlock:
+ xfs_dqfunlock(dqp);
+ return -EIO;
+}
+
+/*
+ * 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);
+ }
+}
+
+int __init
+xfs_qm_init(void)
+{
+ xfs_qm_dqzone =
+ kmem_zone_init(sizeof(struct xfs_dquot), "xfs_dquot");
+ if (!xfs_qm_dqzone)
+ goto out;
+
+ xfs_qm_dqtrxzone =
+ kmem_zone_init(sizeof(struct xfs_dquot_acct), "xfs_dqtrx");
+ if (!xfs_qm_dqtrxzone)
+ goto out_free_dqzone;
+
+ return 0;
+
+out_free_dqzone:
+ kmem_zone_destroy(xfs_qm_dqzone);
+out:
+ return -ENOMEM;
+}
+
+void
+xfs_qm_exit(void)
+{
+ kmem_zone_destroy(xfs_qm_dqtrxzone);
+ kmem_zone_destroy(xfs_qm_dqzone);
+}
+
+/*
+ * 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 XFS_BTREE_QUERY_RANGE_ABORT to indicate that it wants to stop iterating.
+ */
+int
+xfs_qm_dqiterate(
+ struct xfs_mount *mp,
+ uint dqtype,
+ 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, dqtype, &dq);
+ if (error == -ENOENT)
+ return 0;
+ if (error)
+ return error;
+
+ error = iter_fn(dq, dqtype, priv);
+ id = be32_to_cpu(dq->q_core.d_id);
+ xfs_qm_dqput(dq);
+ id++;
+ } while (error == 0 && id != 0);
+
+ return error;
+}