fs/xfs/xfs_dquot_item.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2003 Silicon Graphics, Inc.
   4  * All Rights Reserved.
   5  */
   6 #include "xfs.h"
   7 #include "xfs_fs.h"
   8 #include "xfs_shared.h"
   9 #include "xfs_format.h"
  10 #include "xfs_log_format.h"
  11 #include "xfs_trans_resv.h"
  12 #include "xfs_mount.h"
  13 #include "xfs_inode.h"
  14 #include "xfs_quota.h"
  15 #include "xfs_trans.h"
  16 #include "xfs_buf_item.h"
  17 #include "xfs_trans_priv.h"
  18 #include "xfs_qm.h"
  19 #include "xfs_log.h"
  20
  21 static inline struct xfs_dq_logitem *DQUOT_ITEM(struct xfs_log_item *lip)
  22 {
  23         return container_of(lip, struct xfs_dq_logitem, qli_item);
  24 }
  25
  26 /*
  27  * returns the number of iovecs needed to log the given dquot item.
  28  */
  29 STATIC void
  30 xfs_qm_dquot_logitem_size(
  31         struct xfs_log_item     *lip,
  32         int                     *nvecs,
  33         int                     *nbytes)
  34 {
  35         *nvecs += 2;
  36         *nbytes += sizeof(struct xfs_dq_logformat) +
  37                    sizeof(struct xfs_disk_dquot);
  38 }
  39
  40 /*
  41  * fills in the vector of log iovecs for the given dquot log item.
  42  */
  43 STATIC void
  44 xfs_qm_dquot_logitem_format(
  45         struct xfs_log_item     *lip,
  46         struct xfs_log_vec      *lv)
  47 {
  48         struct xfs_disk_dquot   ddq;
  49         struct xfs_dq_logitem   *qlip = DQUOT_ITEM(lip);
  50         struct xfs_log_iovec    *vecp = NULL;
  51         struct xfs_dq_logformat *qlf;
  52
  53         qlf = xlog_prepare_iovec(lv, &vecp, XLOG_REG_TYPE_QFORMAT);
  54         qlf->qlf_type = XFS_LI_DQUOT;
  55         qlf->qlf_size = 2;
  56         qlf->qlf_id = qlip->qli_dquot->q_id;
  57         qlf->qlf_blkno = qlip->qli_dquot->q_blkno;
  58         qlf->qlf_len = 1;
  59         qlf->qlf_boffset = qlip->qli_dquot->q_bufoffset;
  60         xlog_finish_iovec(lv, vecp, sizeof(struct xfs_dq_logformat));
  61
  62         xfs_dquot_to_disk(&ddq, qlip->qli_dquot);
  63
  64         xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_DQUOT, &ddq,
  65                         sizeof(struct xfs_disk_dquot));
  66 }
  67
  68 /*
  69  * Increment the pin count of the given dquot.
  70  */
  71 STATIC void
  72 xfs_qm_dquot_logitem_pin(
  73         struct xfs_log_item     *lip)
  74 {
  75         struct xfs_dquot        *dqp = DQUOT_ITEM(lip)->qli_dquot;
  76
  77         ASSERT(XFS_DQ_IS_LOCKED(dqp));
  78         atomic_inc(&dqp->q_pincount);
  79 }
  80
  81 /*
  82  * Decrement the pin count of the given dquot, and wake up
  83  * anyone in xfs_dqwait_unpin() if the count goes to 0.  The
  84  * dquot must have been previously pinned with a call to
  85  * xfs_qm_dquot_logitem_pin().
  86  */
  87 STATIC void
  88 xfs_qm_dquot_logitem_unpin(
  89         struct xfs_log_item     *lip,
  90         int                     remove)
  91 {
  92         struct xfs_dquot        *dqp = DQUOT_ITEM(lip)->qli_dquot;
  93
  94         ASSERT(atomic_read(&dqp->q_pincount) > 0);
  95         if (atomic_dec_and_test(&dqp->q_pincount))
  96                 wake_up(&dqp->q_pinwait);
  97 }
  98
  99 /*
 100  * This is called to wait for the given dquot to be unpinned.
 101  * Most of these pin/unpin routines are plagiarized from inode code.
 102  */
 103 void
 104 xfs_qm_dqunpin_wait(
 105         struct xfs_dquot        *dqp)
 106 {
 107         ASSERT(XFS_DQ_IS_LOCKED(dqp));
 108         if (atomic_read(&dqp->q_pincount) == 0)
 109                 return;
 110
 111         /*
 112          * Give the log a push so we don't wait here too long.
 113          */
 114         xfs_log_force(dqp->q_mount, 0);
 115         wait_event(dqp->q_pinwait, (atomic_read(&dqp->q_pincount) == 0));
 116 }
 117
 118 STATIC uint
 119 xfs_qm_dquot_logitem_push(
 120         struct xfs_log_item     *lip,
 121         struct list_head        *buffer_list)
 122                 __releases(&lip->li_ailp->ail_lock)
 123                 __acquires(&lip->li_ailp->ail_lock)
 124 {
 125         struct xfs_dquot        *dqp = DQUOT_ITEM(lip)->qli_dquot;
 126         struct xfs_buf          *bp = lip->li_buf;
 127         uint                    rval = XFS_ITEM_SUCCESS;
 128         int                     error;
 129
 130         if (atomic_read(&dqp->q_pincount) > 0)
 131                 return XFS_ITEM_PINNED;
 132
 133         if (!xfs_dqlock_nowait(dqp))
 134                 return XFS_ITEM_LOCKED;
 135
 136         /*
 137          * Re-check the pincount now that we stabilized the value by
 138          * taking the quota lock.
 139          */
 140         if (atomic_read(&dqp->q_pincount) > 0) {
 141                 rval = XFS_ITEM_PINNED;
 142                 goto out_unlock;
 143         }
 144
 145         /*
 146          * Someone else is already flushing the dquot.  Nothing we can do
 147          * here but wait for the flush to finish and remove the item from
 148          * the AIL.
 149          */
 150         if (!xfs_dqflock_nowait(dqp)) {
 151                 rval = XFS_ITEM_FLUSHING;
 152                 goto out_unlock;
 153         }
 154
 155         spin_unlock(&lip->li_ailp->ail_lock);
 156
 157         error = xfs_qm_dqflush(dqp, &bp);
 158         if (!error) {
 159                 if (!xfs_buf_delwri_queue(bp, buffer_list))
 160                         rval = XFS_ITEM_FLUSHING;
 161                 xfs_buf_relse(bp);
 162         } else if (error == -EAGAIN)
 163                 rval = XFS_ITEM_LOCKED;
 164
 165         spin_lock(&lip->li_ailp->ail_lock);
 166 out_unlock:
 167         xfs_dqunlock(dqp);
 168         return rval;
 169 }
 170
 171 STATIC void
 172 xfs_qm_dquot_logitem_release(
 173         struct xfs_log_item     *lip)
 174 {
 175         struct xfs_dquot        *dqp = DQUOT_ITEM(lip)->qli_dquot;
 176
 177         ASSERT(XFS_DQ_IS_LOCKED(dqp));
 178
 179         /*
 180          * dquots are never 'held' from getting unlocked at the end of
 181          * a transaction.  Their locking and unlocking is hidden inside the
 182          * transaction layer, within trans_commit. Hence, no LI_HOLD flag
 183          * for the logitem.
 184          */
 185         xfs_dqunlock(dqp);
 186 }
 187
 188 STATIC void
 189 xfs_qm_dquot_logitem_committing(
 190         struct xfs_log_item     *lip,
 191         xfs_csn_t               seq)
 192 {
 193         return xfs_qm_dquot_logitem_release(lip);
 194 }
 195
 196 static const struct xfs_item_ops xfs_dquot_item_ops = {
 197         .iop_size       = xfs_qm_dquot_logitem_size,
 198         .iop_format     = xfs_qm_dquot_logitem_format,
 199         .iop_pin        = xfs_qm_dquot_logitem_pin,
 200         .iop_unpin      = xfs_qm_dquot_logitem_unpin,
 201         .iop_release    = xfs_qm_dquot_logitem_release,
 202         .iop_committing = xfs_qm_dquot_logitem_committing,
 203         .iop_push       = xfs_qm_dquot_logitem_push,
 204 };
 205
 206 /*
 207  * Initialize the dquot log item for a newly allocated dquot.
 208  * The dquot isn't locked at this point, but it isn't on any of the lists
 209  * either, so we don't care.
 210  */
 211 void
 212 xfs_qm_dquot_logitem_init(
 213         struct xfs_dquot        *dqp)
 214 {
 215         struct xfs_dq_logitem   *lp = &dqp->q_logitem;
 216
 217         xfs_log_item_init(dqp->q_mount, &lp->qli_item, XFS_LI_DQUOT,
 218                                         &xfs_dquot_item_ops);
 219         lp->qli_dquot = dqp;
 220 }