fs/xfs/xfs_dquot_item.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (c) 2000-2003 Silicon Graphics, Inc.
0004  * All Rights Reserved.
0005  */
0006 #include "xfs.h"
0007 #include "xfs_fs.h"
0008 #include "xfs_shared.h"
0009 #include "xfs_format.h"
0010 #include "xfs_log_format.h"
0011 #include "xfs_trans_resv.h"
0012 #include "xfs_mount.h"
0013 #include "xfs_inode.h"
0014 #include "xfs_quota.h"
0015 #include "xfs_trans.h"
0016 #include "xfs_buf_item.h"
0017 #include "xfs_trans_priv.h"
0018 #include "xfs_qm.h"
0019 #include "xfs_log.h"
0020
0021 static inline struct xfs_dq_logitem *DQUOT_ITEM(struct xfs_log_item *lip)
0022 {
0023     return container_of(lip, struct xfs_dq_logitem, qli_item);
0024 }
0025
0026 /*
0027  * returns the number of iovecs needed to log the given dquot item.
0028  */
0029 STATIC void
0030 xfs_qm_dquot_logitem_size(
0031     struct xfs_log_item *lip,
0032     int         *nvecs,
0033     int         *nbytes)
0034 {
0035     *nvecs += 2;
0036     *nbytes += sizeof(struct xfs_dq_logformat) +
0037            sizeof(struct xfs_disk_dquot);
0038 }
0039
0040 /*
0041  * fills in the vector of log iovecs for the given dquot log item.
0042  */
0043 STATIC void
0044 xfs_qm_dquot_logitem_format(
0045     struct xfs_log_item *lip,
0046     struct xfs_log_vec  *lv)
0047 {
0048     struct xfs_disk_dquot   ddq;
0049     struct xfs_dq_logitem   *qlip = DQUOT_ITEM(lip);
0050     struct xfs_log_iovec    *vecp = NULL;
0051     struct xfs_dq_logformat *qlf;
0052
0053     qlf = xlog_prepare_iovec(lv, &vecp, XLOG_REG_TYPE_QFORMAT);
0054     qlf->qlf_type = XFS_LI_DQUOT;
0055     qlf->qlf_size = 2;
0056     qlf->qlf_id = qlip->qli_dquot->q_id;
0057     qlf->qlf_blkno = qlip->qli_dquot->q_blkno;
0058     qlf->qlf_len = 1;
0059     qlf->qlf_boffset = qlip->qli_dquot->q_bufoffset;
0060     xlog_finish_iovec(lv, vecp, sizeof(struct xfs_dq_logformat));
0061
0062     xfs_dquot_to_disk(&ddq, qlip->qli_dquot);
0063
0064     xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_DQUOT, &ddq,
0065             sizeof(struct xfs_disk_dquot));
0066 }
0067
0068 /*
0069  * Increment the pin count of the given dquot.
0070  */
0071 STATIC void
0072 xfs_qm_dquot_logitem_pin(
0073     struct xfs_log_item *lip)
0074 {
0075     struct xfs_dquot    *dqp = DQUOT_ITEM(lip)->qli_dquot;
0076
0077     ASSERT(XFS_DQ_IS_LOCKED(dqp));
0078     atomic_inc(&dqp->q_pincount);
0079 }
0080
0081 /*
0082  * Decrement the pin count of the given dquot, and wake up
0083  * anyone in xfs_dqwait_unpin() if the count goes to 0.  The
0084  * dquot must have been previously pinned with a call to
0085  * xfs_qm_dquot_logitem_pin().
0086  */
0087 STATIC void
0088 xfs_qm_dquot_logitem_unpin(
0089     struct xfs_log_item *lip,
0090     int         remove)
0091 {
0092     struct xfs_dquot    *dqp = DQUOT_ITEM(lip)->qli_dquot;
0093
0094     ASSERT(atomic_read(&dqp->q_pincount) > 0);
0095     if (atomic_dec_and_test(&dqp->q_pincount))
0096         wake_up(&dqp->q_pinwait);
0097 }
0098
0099 /*
0100  * This is called to wait for the given dquot to be unpinned.
0101  * Most of these pin/unpin routines are plagiarized from inode code.
0102  */
0103 void
0104 xfs_qm_dqunpin_wait(
0105     struct xfs_dquot    *dqp)
0106 {
0107     ASSERT(XFS_DQ_IS_LOCKED(dqp));
0108     if (atomic_read(&dqp->q_pincount) == 0)
0109         return;
0110
0111     /*
0112      * Give the log a push so we don't wait here too long.
0113      */
0114     xfs_log_force(dqp->q_mount, 0);
0115     wait_event(dqp->q_pinwait, (atomic_read(&dqp->q_pincount) == 0));
0116 }
0117
0118 STATIC uint
0119 xfs_qm_dquot_logitem_push(
0120     struct xfs_log_item *lip,
0121     struct list_head    *buffer_list)
0122         __releases(&lip->li_ailp->ail_lock)
0123         __acquires(&lip->li_ailp->ail_lock)
0124 {
0125     struct xfs_dquot    *dqp = DQUOT_ITEM(lip)->qli_dquot;
0126     struct xfs_buf      *bp = lip->li_buf;
0127     uint            rval = XFS_ITEM_SUCCESS;
0128     int         error;
0129
0130     if (atomic_read(&dqp->q_pincount) > 0)
0131         return XFS_ITEM_PINNED;
0132
0133     if (!xfs_dqlock_nowait(dqp))
0134         return XFS_ITEM_LOCKED;
0135
0136     /*
0137      * Re-check the pincount now that we stabilized the value by
0138      * taking the quota lock.
0139      */
0140     if (atomic_read(&dqp->q_pincount) > 0) {
0141         rval = XFS_ITEM_PINNED;
0142         goto out_unlock;
0143     }
0144
0145     /*
0146      * Someone else is already flushing the dquot.  Nothing we can do
0147      * here but wait for the flush to finish and remove the item from
0148      * the AIL.
0149      */
0150     if (!xfs_dqflock_nowait(dqp)) {
0151         rval = XFS_ITEM_FLUSHING;
0152         goto out_unlock;
0153     }
0154
0155     spin_unlock(&lip->li_ailp->ail_lock);
0156
0157     error = xfs_qm_dqflush(dqp, &bp);
0158     if (!error) {
0159         if (!xfs_buf_delwri_queue(bp, buffer_list))
0160             rval = XFS_ITEM_FLUSHING;
0161         xfs_buf_relse(bp);
0162     } else if (error == -EAGAIN)
0163         rval = XFS_ITEM_LOCKED;
0164
0165     spin_lock(&lip->li_ailp->ail_lock);
0166 out_unlock:
0167     xfs_dqunlock(dqp);
0168     return rval;
0169 }
0170
0171 STATIC void
0172 xfs_qm_dquot_logitem_release(
0173     struct xfs_log_item *lip)
0174 {
0175     struct xfs_dquot    *dqp = DQUOT_ITEM(lip)->qli_dquot;
0176
0177     ASSERT(XFS_DQ_IS_LOCKED(dqp));
0178
0179     /*
0180      * dquots are never 'held' from getting unlocked at the end of
0181      * a transaction.  Their locking and unlocking is hidden inside the
0182      * transaction layer, within trans_commit. Hence, no LI_HOLD flag
0183      * for the logitem.
0184      */
0185     xfs_dqunlock(dqp);
0186 }
0187
0188 STATIC void
0189 xfs_qm_dquot_logitem_committing(
0190     struct xfs_log_item *lip,
0191     xfs_csn_t       seq)
0192 {
0193     return xfs_qm_dquot_logitem_release(lip);
0194 }
0195
0196 static const struct xfs_item_ops xfs_dquot_item_ops = {
0197     .iop_size   = xfs_qm_dquot_logitem_size,
0198     .iop_format = xfs_qm_dquot_logitem_format,
0199     .iop_pin    = xfs_qm_dquot_logitem_pin,
0200     .iop_unpin  = xfs_qm_dquot_logitem_unpin,
0201     .iop_release    = xfs_qm_dquot_logitem_release,
0202     .iop_committing = xfs_qm_dquot_logitem_committing,
0203     .iop_push   = xfs_qm_dquot_logitem_push,
0204 };
0205
0206 /*
0207  * Initialize the dquot log item for a newly allocated dquot.
0208  * The dquot isn't locked at this point, but it isn't on any of the lists
0209  * either, so we don't care.
0210  */
0211 void
0212 xfs_qm_dquot_logitem_init(
0213     struct xfs_dquot    *dqp)
0214 {
0215     struct xfs_dq_logitem   *lp = &dqp->q_logitem;
0216
0217     xfs_log_item_init(dqp->q_mount, &lp->qli_item, XFS_LI_DQUOT,
0218                     &xfs_dquot_item_ops);
0219     lp->qli_dquot = dqp;
0220 }