/* * 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; }
/* * Read in the ondisk dquot using dqtobp() then copy it to an incore version, * and release the buffer immediately. * * If XFS_QMOPT_DQALLOC is set, allocate a dquot on disk if it needed. */ int xfs_qm_dqread( struct xfs_mount *mp, xfs_dqid_t id, uint type, uint flags, struct xfs_dquot **O_dqpp) { struct xfs_dquot *dqp; struct xfs_disk_dquot *ddqp; struct xfs_buf *bp; struct xfs_trans *tp = NULL; int error; int cancelflags = 0; 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); /* * 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_STATS_INC(xs_qm_dquot); trace_xfs_dqread(dqp); if (flags & XFS_QMOPT_DQALLOC) { tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC); error = xfs_trans_reserve(tp, &M_RES(mp)->tr_qm_dqalloc, XFS_QM_DQALLOC_SPACE_RES(mp), 0); if (error) goto error1; cancelflags = XFS_TRANS_RELEASE_LOG_RES; } /* * get a pointer to the on-disk dquot and the buffer containing it * dqp already knows its own type (GROUP/USER). */ error = xfs_qm_dqtobp(&tp, dqp, &ddqp, &bp, flags); if (error) { /* * 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 error1; } /* copy everything from disk dquot to the incore dquot */ memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t)); 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); /* initialize the dquot speculative prealloc thresholds */ xfs_dquot_set_prealloc_limits(dqp); /* Mark the buf so that this will stay incore a little longer */ xfs_buf_set_ref(bp, 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); if (tp) { error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); if (error) goto error0; } *O_dqpp = dqp; return error; error1: if (tp) xfs_trans_cancel(tp, cancelflags); error0: xfs_qm_dqdestroy(dqp); *O_dqpp = NULL; return error; }