/* * Copyright (c) 2000-2003 Silicon Graphics, Inc. * All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation. * * This program is distributed in the hope that it would be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include "xfs.h" #include "xfs_fs.h" #include "xfs_bit.h" #include "xfs_log.h" #include "xfs_inum.h" #include "xfs_trans.h" #include "xfs_sb.h" #include "xfs_ag.h" #include "xfs_alloc.h" #include "xfs_quota.h" #include "xfs_mount.h" #include "xfs_bmap_btree.h" #include "xfs_inode.h" #include "xfs_bmap.h" #include "xfs_rtalloc.h" #include "xfs_error.h" #include "xfs_itable.h" #include "xfs_attr.h" #include "xfs_buf_item.h" #include "xfs_trans_space.h" #include "xfs_trans_priv.h" #include "xfs_qm.h" #include "xfs_trace.h" /* * Lock order: * * ip->i_lock * qh->qh_lock * qi->qi_dqlist_lock * dquot->q_qlock (xfs_dqlock() and friends) * dquot->q_flush (xfs_dqflock() and friends) * xfs_Gqm->qm_dqfrlist_lock * * If two dquots need to be locked the order is user before group/project, * otherwise by the lowest id first, see xfs_dqlock2. */ #ifdef DEBUG xfs_buftarg_t *xfs_dqerror_target; int xfs_do_dqerror; int xfs_dqreq_num; int xfs_dqerror_mod = 33; #endif static struct lock_class_key xfs_dquot_other_class; /* * Allocate and initialize a dquot. We don't always allocate fresh memory; * we try to reclaim a free dquot if the number of incore dquots are above * a threshold. * The only field inside the core that gets initialized at this point * is the d_id field. The idea is to fill in the entire q_core * when we read in the on disk dquot. */ STATIC xfs_dquot_t * xfs_qm_dqinit( xfs_mount_t *mp, xfs_dqid_t id, uint type) { xfs_dquot_t *dqp; boolean_t brandnewdquot; brandnewdquot = xfs_qm_dqalloc_incore(&dqp); dqp->dq_flags = type; dqp->q_core.d_id = cpu_to_be32(id); dqp->q_mount = mp; /* * No need to re-initialize these if this is a reclaimed dquot. */ if (brandnewdquot) { INIT_LIST_HEAD(&dqp->q_freelist); 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); trace_xfs_dqinit(dqp); } else { /* * Only the q_core portion was zeroed in dqreclaim_one(). * So, we need to reset others. */ dqp->q_nrefs = 0; dqp->q_blkno = 0; INIT_LIST_HEAD(&dqp->q_mplist); INIT_LIST_HEAD(&dqp->q_hashlist); dqp->q_bufoffset = 0; dqp->q_fileoffset = 0; dqp->q_transp = NULL; dqp->q_gdquot = NULL; dqp->q_res_bcount = 0; dqp->q_res_icount = 0; dqp->q_res_rtbcount = 0; atomic_set(&dqp->q_pincount, 0); dqp->q_hash = NULL; ASSERT(list_empty(&dqp->q_freelist)); trace_xfs_dqreuse(dqp); } /* * In either case we need to make sure group quotas have a different * lock class than user quotas, to make sure lockdep knows we can * locks of one of each at the same time. */ if (!(type & XFS_DQ_USER)) lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class); /* * log item gets initialized later */ return (dqp); } /* * 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_freelist)); mutex_destroy(&dqp->q_qlock); kmem_zone_free(xfs_Gqm->qm_dqzone, dqp); atomic_dec(&xfs_Gqm->qm_totaldquots); } /* * 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( xfs_mount_t *mp, xfs_disk_dquot_t *d) { xfs_quotainfo_t *q = mp->m_quotainfo; ASSERT(d->d_id); if (q->qi_bsoftlimit && !d->d_blk_softlimit) d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit); if (q->qi_bhardlimit && !d->d_blk_hardlimit) d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit); if (q->qi_isoftlimit && !d->d_ino_softlimit) d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit); if (q->qi_ihardlimit && !d->d_ino_hardlimit) d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit); if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit) d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit); if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit) d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit); } /* * 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; int curid, 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); ASSERT(curid >= 0); 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; } 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); } /* * Allocate a block and fill it with dquots. * This is called when the bmapi finds a hole. */ STATIC int xfs_qm_dqalloc( xfs_trans_t **tpp, xfs_mount_t *mp, xfs_dquot_t *dqp, xfs_inode_t *quotip, xfs_fileoff_t offset_fsb, xfs_buf_t **O_bpp) { xfs_fsblock_t firstblock; xfs_bmap_free_t flist; xfs_bmbt_irec_t map; int nmaps, error, committed; xfs_buf_t *bp; xfs_trans_t *tp = *tpp; ASSERT(tp != NULL); trace_xfs_dqalloc(dqp); /* * Initialize the bmap freelist prior to calling bmapi code. */ xfs_bmap_init(&flist, &firstblock); xfs_ilock(quotip, XFS_ILOCK_EXCL); /* * Return if this type of quotas is turned off while we didn't * have an inode lock */ if (XFS_IS_THIS_QUOTA_OFF(dqp)) { xfs_iunlock(quotip, XFS_ILOCK_EXCL); return (ESRCH); } xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL); nmaps = 1; error = xfs_bmapi_write(tp, quotip, offset_fsb, XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA, &firstblock, XFS_QM_DQALLOC_SPACE_RES(mp), &map, &nmaps, &flist); if (error) goto error0; 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); error = xfs_buf_geterror(bp); if (error) goto error1; /* * 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_bmap_finish() may commit the current transaction and * start a second transaction if the freelist is not empty. * * Since we still want to modify this buffer, we need to * ensure that the buffer is not released on commit of * the first transaction and ensure the buffer is added to the * second transaction. * * If there is only one transaction then don't stop the buffer * from being released when it commits later on. */ xfs_trans_bhold(tp, bp); if ((error = xfs_bmap_finish(tpp, &flist, &committed))) { goto error1; } if (committed) { tp = *tpp; xfs_trans_bjoin(tp, bp); } else { xfs_trans_bhold_release(tp, bp); } *O_bpp = bp; return 0; error1: xfs_bmap_cancel(&flist); error0: xfs_iunlock(quotip, XFS_ILOCK_EXCL); return (error); } /* * Maps a dquot to the buffer containing its on-disk version. * This returns a ptr to the buffer containing the on-disk dquot * in the bpp param, and a ptr to the on-disk dquot within that buffer */ STATIC int xfs_qm_dqtobp( xfs_trans_t **tpp, xfs_dquot_t *dqp, xfs_disk_dquot_t **O_ddpp, xfs_buf_t **O_bpp, uint flags) { xfs_bmbt_irec_t map; int nmaps = 1, error; xfs_buf_t *bp; xfs_inode_t *quotip = XFS_DQ_TO_QIP(dqp); xfs_mount_t *mp = dqp->q_mount; xfs_disk_dquot_t *ddq; xfs_dqid_t id = be32_to_cpu(dqp->q_core.d_id); xfs_trans_t *tp = (tpp ? *tpp : NULL); dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk; xfs_ilock(quotip, XFS_ILOCK_SHARED); if (XFS_IS_THIS_QUOTA_OFF(dqp)) { /* * Return if this type of quotas is turned off while we * didn't have the quota inode lock. */ xfs_iunlock(quotip, XFS_ILOCK_SHARED); 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, XFS_ILOCK_SHARED); if (error) return error; ASSERT(nmaps == 1); ASSERT(map.br_blockcount == 1); /* * Offset of dquot in the (fixed sized) dquot chunk. */ dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) * sizeof(xfs_dqblk_t); ASSERT(map.br_startblock != DELAYSTARTBLOCK); if (map.br_startblock == HOLESTARTBLOCK) { /* * We don't allocate unless we're asked to */ if (!(flags & XFS_QMOPT_DQALLOC)) return ENOENT; ASSERT(tp); error = xfs_qm_dqalloc(tpp, mp, dqp, quotip, dqp->q_fileoffset, &bp); if (error) return error; tp = *tpp; } else { 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, tp, mp->m_ddev_targp, dqp->q_blkno, mp->m_quotainfo->qi_dqchunklen, 0, &bp); if (error || !bp) return XFS_ERROR(error); } ASSERT(xfs_buf_islocked(bp)); /* * calculate the location of the dquot inside the buffer. */ ddq = bp->b_addr + dqp->q_bufoffset; /* * A simple sanity check in case we got a corrupted dquot... */ error = xfs_qm_dqcheck(mp, ddq, id, dqp->dq_flags & XFS_DQ_ALLTYPES, flags & (XFS_QMOPT_DQREPAIR|XFS_QMOPT_DOWARN), "dqtobp"); if (error) { if (!(flags & XFS_QMOPT_DQREPAIR)) { xfs_trans_brelse(tp, bp); return XFS_ERROR(EIO); } } *O_bpp = bp; *O_ddpp = ddq; return (0); } /* * 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 = xfs_qm_dqinit(mp, id, type); trace_xfs_dqread(dqp); if (flags & XFS_QMOPT_DQALLOC) { tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC); error = xfs_trans_reserve(tp, XFS_QM_DQALLOC_SPACE_RES(mp), XFS_WRITE_LOG_RES(mp) + /* * Round the chunklen up to the next multiple * of 128 (buf log item chunk size)). */ BBTOB(mp->m_quotainfo->qi_dqchunklen) - 1 + 128, 0, XFS_TRANS_PERM_LOG_RES, XFS_WRITE_LOG_COUNT); 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); /* 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; } /* * Lookup a dquot in the incore dquot hashtable. We keep two separate * hashtables for user and group dquots; and, these are global tables * inside the XQM, not per-filesystem tables. * The hash chain must be locked by caller, and it is left locked * on return. Returning dquot is locked. */ STATIC int xfs_qm_dqlookup( xfs_mount_t *mp, xfs_dqid_t id, xfs_dqhash_t *qh, xfs_dquot_t **O_dqpp) { xfs_dquot_t *dqp; ASSERT(mutex_is_locked(&qh->qh_lock)); /* * Traverse the hashchain looking for a match */ list_for_each_entry(dqp, &qh->qh_list, q_hashlist) { /* * We already have the hashlock. We don't need the * dqlock to look at the id field of the dquot, since the * id can't be modified without the hashlock anyway. */ if (be32_to_cpu(dqp->q_core.d_id) != id || dqp->q_mount != mp) continue; trace_xfs_dqlookup_found(dqp); xfs_dqlock(dqp); if (dqp->dq_flags & XFS_DQ_FREEING) { *O_dqpp = NULL; xfs_dqunlock(dqp); return -1; } dqp->q_nrefs++; /* * move the dquot to the front of the hashchain */ list_move(&dqp->q_hashlist, &qh->qh_list); trace_xfs_dqlookup_done(dqp); *O_dqpp = dqp; return 0; } *O_dqpp = NULL; return 1; } /* * 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 */ { xfs_dquot_t *dqp; xfs_dqhash_t *h; uint version; 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); } h = XFS_DQ_HASH(mp, id, type); #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)); if (type == XFS_DQ_USER) ASSERT(ip->i_udquot == NULL); else ASSERT(ip->i_gdquot == NULL); } #endif restart: mutex_lock(&h->qh_lock); /* * Look in the cache (hashtable). * The chain is kept locked during lookup. */ switch (xfs_qm_dqlookup(mp, id, h, O_dqpp)) { case -1: XQM_STATS_INC(xqmstats.xs_qm_dquot_dups); mutex_unlock(&h->qh_lock); delay(1); goto restart; case 0: XQM_STATS_INC(xqmstats.xs_qm_dqcachehits); /* * The dquot was found, moved to the front of the chain, * taken off the freelist if it was on it, and locked * at this point. Just unlock the hashchain and return. */ ASSERT(*O_dqpp); ASSERT(XFS_DQ_IS_LOCKED(*O_dqpp)); mutex_unlock(&h->qh_lock); trace_xfs_dqget_hit(*O_dqpp); return 0; /* success */ default: XQM_STATS_INC(xqmstats.xs_qm_dqcachemisses); break; } /* * 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); /* * Save the hashchain version stamp, and unlock the chain, so that * we don't keep the lock across a disk read */ version = h->qh_version; mutex_unlock(&h->qh_lock); error = xfs_qm_dqread(mp, id, type, flags, &dqp); if (ip) xfs_ilock(ip, XFS_ILOCK_EXCL); if (error) return error; /* * Dquot lock comes after hashlock in the lock ordering */ if (ip) { /* * A dquot could be attached to this inode by now, since * we had dropped the ilock. */ if (type == XFS_DQ_USER) { if (!XFS_IS_UQUOTA_ON(mp)) { /* inode stays locked on return */ xfs_qm_dqdestroy(dqp); return XFS_ERROR(ESRCH); } if (ip->i_udquot) { xfs_qm_dqdestroy(dqp); dqp = ip->i_udquot; xfs_dqlock(dqp); goto dqret; } } else { if (!XFS_IS_OQUOTA_ON(mp)) { /* inode stays locked on return */ xfs_qm_dqdestroy(dqp); return XFS_ERROR(ESRCH); } if (ip->i_gdquot) { xfs_qm_dqdestroy(dqp); dqp = ip->i_gdquot; xfs_dqlock(dqp); goto dqret; } } } /* * Hashlock comes after ilock in lock order */ mutex_lock(&h->qh_lock); if (version != h->qh_version) { xfs_dquot_t *tmpdqp; /* * Now, see if somebody else put the dquot in the * hashtable before us. This can happen because we didn't * keep the hashchain lock. We don't have to worry about * lock order between the two dquots here since dqp isn't * on any findable lists yet. */ switch (xfs_qm_dqlookup(mp, id, h, &tmpdqp)) { case 0: case -1: /* * Duplicate found, either in cache or on its way out. * Just throw away the new dquot and start over. */ if (tmpdqp) xfs_qm_dqput(tmpdqp); mutex_unlock(&h->qh_lock); xfs_qm_dqdestroy(dqp); XQM_STATS_INC(xqmstats.xs_qm_dquot_dups); goto restart; default: break; } } /* * Put the dquot at the beginning of the hash-chain and mp's list * LOCK ORDER: hashlock, freelistlock, mplistlock, udqlock, gdqlock .. */ ASSERT(mutex_is_locked(&h->qh_lock)); dqp->q_hash = h; list_add(&dqp->q_hashlist, &h->qh_list); h->qh_version++; /* * Attach this dquot to this filesystem's list of all dquots, * kept inside the mount structure in m_quotainfo field */ mutex_lock(&mp->m_quotainfo->qi_dqlist_lock); /* * We return a locked dquot to the caller, with a reference taken */ xfs_dqlock(dqp); dqp->q_nrefs = 1; list_add(&dqp->q_mplist, &mp->m_quotainfo->qi_dqlist); mp->m_quotainfo->qi_dquots++; mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock); mutex_unlock(&h->qh_lock); dqret: ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL)); trace_xfs_dqget_miss(dqp); *O_dqpp = dqp; return (0); } /* * 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) { struct xfs_dquot *gdqp; ASSERT(dqp->q_nrefs > 0); ASSERT(XFS_DQ_IS_LOCKED(dqp)); trace_xfs_dqput(dqp); recurse: if (--dqp->q_nrefs > 0) { xfs_dqunlock(dqp); return; } trace_xfs_dqput_free(dqp); mutex_lock(&xfs_Gqm->qm_dqfrlist_lock); if (list_empty(&dqp->q_freelist)) { list_add_tail(&dqp->q_freelist, &xfs_Gqm->qm_dqfrlist); xfs_Gqm->qm_dqfrlist_cnt++; } mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock); /* * If we just added a udquot to the freelist, then we want to release * the gdquot reference that it (probably) has. Otherwise it'll keep * the gdquot from getting reclaimed. */ gdqp = dqp->q_gdquot; if (gdqp) { xfs_dqlock(gdqp); dqp->q_gdquot = NULL; } xfs_dqunlock(dqp); /* * If we had a group quota hint, release it now. */ if (gdqp) { dqp = gdqp; goto recurse; } } /* * 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 ((lip->li_flags & XFS_LI_IN_AIL) && lip->li_lsn == qip->qli_flush_lsn) { /* xfs_trans_ail_delete() drops the AIL lock. */ spin_lock(&ailp->xa_lock); if (lip->li_lsn == qip->qli_flush_lsn) xfs_trans_ail_delete(ailp, lip); else spin_unlock(&ailp->xa_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( xfs_dquot_t *dqp, uint flags) { struct xfs_mount *mp = dqp->q_mount; struct xfs_buf *bp; struct xfs_disk_dquot *ddqp; int error; ASSERT(XFS_DQ_IS_LOCKED(dqp)); ASSERT(!completion_done(&dqp->q_flush)); trace_xfs_dqflush(dqp); /* * If not dirty, or it's pinned and we are not supposed to block, nada. */ if (!XFS_DQ_IS_DIRTY(dqp) || ((flags & SYNC_TRYLOCK) && atomic_read(&dqp->q_pincount) > 0)) { xfs_dqfunlock(dqp); return 0; } 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! */ if (XFS_FORCED_SHUTDOWN(mp)) { dqp->dq_flags &= ~XFS_DQ_DIRTY; xfs_dqfunlock(dqp); return XFS_ERROR(EIO); } /* * 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); if (error) { ASSERT(error != ENOENT); xfs_dqfunlock(dqp); return error; } /* * Calculate the location of the dquot inside the buffer. */ ddqp = bp->b_addr + dqp->q_bufoffset; /* * A simple sanity check in case we got a corrupted dquot.. */ error = xfs_qm_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0, XFS_QMOPT_DOWARN, "dqflush (incore copy)"); if (error) { xfs_buf_relse(bp); xfs_dqfunlock(dqp); xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); return XFS_ERROR(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); /* * 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); } if (flags & SYNC_WAIT) error = xfs_bwrite(bp); else xfs_buf_delwri_queue(bp); xfs_buf_relse(bp); trace_xfs_dqflush_done(dqp); /* * dqp is still locked, but caller is free to unlock it now. */ return error; } void xfs_dqunlock( xfs_dquot_t *dqp) { xfs_dqunlock_nonotify(dqp); if (dqp->q_logitem.qli_dquot == dqp) { xfs_trans_unlocked_item(dqp->q_logitem.qli_item.li_ailp, &dqp->q_logitem.qli_item); } } /* * 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); } } /* * Take a dquot out of the mount's dqlist as well as the hashlist. This is * called via unmount as well as quotaoff, and the purge will always succeed. */ void xfs_qm_dqpurge( struct xfs_dquot *dqp) { struct xfs_mount *mp = dqp->q_mount; struct xfs_dqhash *qh = dqp->q_hash; xfs_dqlock(dqp); /* * If we're turning off quotas, we have to make sure that, for * example, we don't delete quota disk blocks while dquots are * in the process of getting written to those disk blocks. * This dquot might well be on AIL, and we can't leave it there * if we're turning off quotas. Basically, we need this flush * lock, and are willing to block on it. */ if (!xfs_dqflock_nowait(dqp)) { /* * Block on the flush lock after nudging dquot buffer, * if it is incore. */ xfs_dqflock_pushbuf_wait(dqp); } /* * If we are turning this type of quotas off, we don't care * about the dirty metadata sitting in this dquot. OTOH, if * we're unmounting, we do care, so we flush it and wait. */ if (XFS_DQ_IS_DIRTY(dqp)) { int error; /* * We don't care about getting disk errors here. We need * to purge this dquot anyway, so we go ahead regardless. */ error = xfs_qm_dqflush(dqp, SYNC_WAIT); if (error) xfs_warn(mp, "%s: dquot %p flush failed", __func__, dqp); xfs_dqflock(dqp); } ASSERT(atomic_read(&dqp->q_pincount) == 0); ASSERT(XFS_FORCED_SHUTDOWN(mp) || !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL)); xfs_dqfunlock(dqp); xfs_dqunlock(dqp); mutex_lock(&qh->qh_lock); list_del_init(&dqp->q_hashlist); qh->qh_version++; mutex_unlock(&qh->qh_lock); mutex_lock(&mp->m_quotainfo->qi_dqlist_lock); list_del_init(&dqp->q_mplist); mp->m_quotainfo->qi_dqreclaims++; mp->m_quotainfo->qi_dquots--; mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock); /* * We move dquots to the freelist as soon as their reference count * hits zero, so it really should be on the freelist here. */ mutex_lock(&xfs_Gqm->qm_dqfrlist_lock); ASSERT(!list_empty(&dqp->q_freelist)); list_del_init(&dqp->q_freelist); xfs_Gqm->qm_dqfrlist_cnt--; mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock); xfs_qm_dqdestroy(dqp); } /* * Give the buffer a little push if it is incore and * wait on the flush lock. */ void xfs_dqflock_pushbuf_wait( xfs_dquot_t *dqp) { xfs_mount_t *mp = dqp->q_mount; xfs_buf_t *bp; /* * Check to see if the dquot has been flushed delayed * write. If so, grab its buffer and send it * out immediately. We'll be able to acquire * the flush lock when the I/O completes. */ bp = xfs_incore(mp->m_ddev_targp, dqp->q_blkno, mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK); if (!bp) goto out_lock; if (XFS_BUF_ISDELAYWRITE(bp)) { if (xfs_buf_ispinned(bp)) xfs_log_force(mp, 0); xfs_buf_delwri_promote(bp); wake_up_process(bp->b_target->bt_task); } xfs_buf_relse(bp); out_lock: xfs_dqflock(dqp); }