/* * 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 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 */ { struct xfs_quotainfo *qi = mp->m_quotainfo; struct radix_tree_root *tree = xfs_dquot_tree(qi, type); struct xfs_dquot *dqp; 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); } #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); } } ASSERT(type == XFS_DQ_USER || type == XFS_DQ_PROJ || type == XFS_DQ_GROUP); if (ip) { ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); ASSERT(xfs_inode_dquot(ip, type) == NULL); } #endif restart: mutex_lock(&qi->qi_tree_lock); dqp = radix_tree_lookup(tree, id); if (dqp) { 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(xs_qm_dqcachehits); *O_dqpp = dqp; return 0; } mutex_unlock(&qi->qi_tree_lock); XFS_STATS_INC(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); error = xfs_qm_dqread(mp, id, type, flags, &dqp); if (ip) xfs_ilock(ip, XFS_ILOCK_EXCL); if (error) return error; if (ip) { /* * 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 XFS_ERROR(ESRCH); } } mutex_lock(&qi->qi_tree_lock); error = -radix_tree_insert(tree, id, dqp); if (unlikely(error)) { WARN_ON(error != EEXIST); /* * Duplicate found. Just throw away the new dquot and start * over. */ mutex_unlock(&qi->qi_tree_lock); trace_xfs_dqget_dup(dqp); xfs_qm_dqdestroy(dqp); XFS_STATS_INC(xs_qm_dquot_dups); goto restart; } /* * We 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); dqret: ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL)); trace_xfs_dqget_miss(dqp); *O_dqpp = dqp; 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; }