aboutsummaryrefslogblamecommitdiffstats
path: root/fs/xfs/quota/xfs_qm.c
blob: efde16e0a91345b182aa1731c42f8388dd8cf31e (plain) (tree)
1
2
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
  
                                                                       
















































































                                                                          
                                      



                                                              




                                                        
                                                     
                                                     
































































































                                                                             
           






















































































































                                                                                
                                                       
           
                                                                        
















                                                                             




                                                                      





























                                                                            












                                                                           
                                         
 
















                                                                        





                                                                
         
 































































































                                                                               
          






































































































                                                                           
                                                                            










                                                              
                                                               












































































































                                                                               
                                                                       


                                                                        
                                                                        





























































































































































                                                                              

                                                                    





































                                                                                






                                                                               

















































                                                                                
                                         



























                                                               
                           
                                                                     



                                            
                                                                     



























































































































                                                                                 
          



















































                                                                                


                                                                        





























                                                                         



                                                                         
























                                                                             
                                                            










































































































                                                                              
                                   


                                             









                                                                                



















































































































































                                                                              
                                                                  

                                                          
                                                            

















                                                                    
                             




                                                      

                                                                        

















                                                                             
                                                                    










                                               
                                                                         













































































































































































































































































                                                                                  
                                   















































                                                                          
                                                                              









                                                                          

                                                                              
                                          
                                         

























                                                                               
                                                                        





















                                                                             
                                                             














                                                                               
                                                   


































                                                                             
                                           




























                                                                             





                                                                            




















































































































































































































































































































































































































                                                                                 
                             






























                                                                      
                                                                 




































                                                                               
                                                                 





















                                                                            






















                                                                             



























                                                           


                                                                             







                                                  

                                                                       

                                     

                                                                   














                                                     
                                                           










                              
                                          







                                                                       

                                                                     













                                                                                









                                                                            




                                                                              
                                                   















                                                                                
                                                   


                                                                              
                                          







































































                                                                                   
           







                                                       
           
























                                                                
           




























                                                                
          


















                                                              
          








                                                      
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 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.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.	 Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_clnt.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_alloc.h"
#include "xfs_dmapi.h"
#include "xfs_quota.h"
#include "xfs_mount.h"
#include "xfs_alloc_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_attr_sf.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_bmap.h"
#include "xfs_bit.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_itable.h"
#include "xfs_rw.h"
#include "xfs_acl.h"
#include "xfs_cap.h"
#include "xfs_mac.h"
#include "xfs_attr.h"
#include "xfs_buf_item.h"
#include "xfs_trans_space.h"
#include "xfs_utils.h"

#include "xfs_qm.h"

/*
 * The global quota manager. There is only one of these for the entire
 * system, _not_ one per file system. XQM keeps track of the overall
 * quota functionality, including maintaining the freelist and hash
 * tables of dquots.
 */
mutex_t xfs_Gqm_lock;
struct xfs_qm	*xfs_Gqm;

kmem_zone_t	*qm_dqzone;
kmem_zone_t	*qm_dqtrxzone;
STATIC kmem_shaker_t	xfs_qm_shaker;

STATIC void	xfs_qm_list_init(xfs_dqlist_t *, char *, int);
STATIC void	xfs_qm_list_destroy(xfs_dqlist_t *);

STATIC void	xfs_qm_freelist_init(xfs_frlist_t *);
STATIC void	xfs_qm_freelist_destroy(xfs_frlist_t *);
STATIC int	xfs_qm_mplist_nowait(xfs_mount_t *);
STATIC int	xfs_qm_dqhashlock_nowait(xfs_dquot_t *);

STATIC int	xfs_qm_init_quotainos(xfs_mount_t *);
STATIC int	xfs_qm_init_quotainfo(xfs_mount_t *);
STATIC int	xfs_qm_shake(int, unsigned int);

#ifdef DEBUG
extern mutex_t	qcheck_lock;
#endif

#ifdef QUOTADEBUG
#define XQM_LIST_PRINT(l, NXT, title) \
{ \
	xfs_dquot_t	*dqp; int i = 0; \
	cmn_err(CE_DEBUG, "%s (#%d)", title, (int) (l)->qh_nelems); \
	for (dqp = (l)->qh_next; dqp != NULL; dqp = dqp->NXT) { \
		cmn_err(CE_DEBUG, "   %d.  \"%d (%s)\"   " \
				  "bcnt = %d, icnt = %d, refs = %d", \
			++i, (int) INT_GET(dqp->q_core.d_id, ARCH_CONVERT), \
			DQFLAGTO_TYPESTR(dqp),	     \
			(int) INT_GET(dqp->q_core.d_bcount, ARCH_CONVERT), \
			(int) INT_GET(dqp->q_core.d_icount, ARCH_CONVERT), \
			(int) dqp->q_nrefs);  } \
}
#else
#define XQM_LIST_PRINT(l, NXT, title) do { } while (0)
#endif

/*
 * Initialize the XQM structure.
 * Note that there is not one quota manager per file system.
 */
STATIC struct xfs_qm *
xfs_Gqm_init(void)
{
	xfs_qm_t		*xqm;
	int			hsize, i;

	xqm = kmem_zalloc(sizeof(xfs_qm_t), KM_SLEEP);
	ASSERT(xqm);

	/*
	 * Initialize the dquot hash tables.
	 */
	hsize = (DQUOT_HASH_HEURISTIC < XFS_QM_NCSIZE_THRESHOLD) ?
		XFS_QM_HASHSIZE_LOW : XFS_QM_HASHSIZE_HIGH;
	xqm->qm_dqhashmask = hsize - 1;

	xqm->qm_usr_dqhtable = (xfs_dqhash_t *)kmem_zalloc(hsize *
						      sizeof(xfs_dqhash_t),
						      KM_SLEEP);
	xqm->qm_grp_dqhtable = (xfs_dqhash_t *)kmem_zalloc(hsize *
						      sizeof(xfs_dqhash_t),
						      KM_SLEEP);
	ASSERT(xqm->qm_usr_dqhtable != NULL);
	ASSERT(xqm->qm_grp_dqhtable != NULL);

	for (i = 0; i < hsize; i++) {
		xfs_qm_list_init(&(xqm->qm_usr_dqhtable[i]), "uxdqh", i);
		xfs_qm_list_init(&(xqm->qm_grp_dqhtable[i]), "gxdqh", i);
	}

	/*
	 * Freelist of all dquots of all file systems
	 */
	xfs_qm_freelist_init(&(xqm->qm_dqfreelist));

	/*
	 * dquot zone. we register our own low-memory callback.
	 */
	if (!qm_dqzone) {
		xqm->qm_dqzone = kmem_zone_init(sizeof(xfs_dquot_t),
						"xfs_dquots");
		qm_dqzone = xqm->qm_dqzone;
	} else
		xqm->qm_dqzone = qm_dqzone;

	xfs_qm_shaker = kmem_shake_register(xfs_qm_shake);

	/*
	 * The t_dqinfo portion of transactions.
	 */
	if (!qm_dqtrxzone) {
		xqm->qm_dqtrxzone = kmem_zone_init(sizeof(xfs_dquot_acct_t),
						   "xfs_dqtrx");
		qm_dqtrxzone = xqm->qm_dqtrxzone;
	} else
		xqm->qm_dqtrxzone = qm_dqtrxzone;

	atomic_set(&xqm->qm_totaldquots, 0);
	xqm->qm_dqfree_ratio = XFS_QM_DQFREE_RATIO;
	xqm->qm_nrefs = 0;
#ifdef DEBUG
	mutex_init(&qcheck_lock, MUTEX_DEFAULT, "qchk");
#endif
	return xqm;
}

/*
 * Destroy the global quota manager when its reference count goes to zero.
 */
STATIC void
xfs_qm_destroy(
	struct xfs_qm	*xqm)
{
	int		hsize, i;

	ASSERT(xqm != NULL);
	ASSERT(xqm->qm_nrefs == 0);
	kmem_shake_deregister(xfs_qm_shaker);
	hsize = xqm->qm_dqhashmask + 1;
	for (i = 0; i < hsize; i++) {
		xfs_qm_list_destroy(&(xqm->qm_usr_dqhtable[i]));
		xfs_qm_list_destroy(&(xqm->qm_grp_dqhtable[i]));
	}
	kmem_free(xqm->qm_usr_dqhtable, hsize * sizeof(xfs_dqhash_t));
	kmem_free(xqm->qm_grp_dqhtable, hsize * sizeof(xfs_dqhash_t));
	xqm->qm_usr_dqhtable = NULL;
	xqm->qm_grp_dqhtable = NULL;
	xqm->qm_dqhashmask = 0;
	xfs_qm_freelist_destroy(&(xqm->qm_dqfreelist));
#ifdef DEBUG
	mutex_destroy(&qcheck_lock);
#endif
	kmem_free(xqm, sizeof(xfs_qm_t));
}

/*
 * Called at mount time to let XQM know that another file system is
 * starting quotas. This isn't crucial information as the individual mount
 * structures are pretty independent, but it helps the XQM keep a
 * global view of what's going on.
 */
/* ARGSUSED */
STATIC int
xfs_qm_hold_quotafs_ref(
	struct xfs_mount *mp)
{
	/*
	 * Need to lock the xfs_Gqm structure for things like this. For example,
	 * the structure could disappear between the entry to this routine and
	 * a HOLD operation if not locked.
	 */
	XFS_QM_LOCK(xfs_Gqm);

	if (xfs_Gqm == NULL)
		xfs_Gqm = xfs_Gqm_init();
	/*
	 * We can keep a list of all filesystems with quotas mounted for
	 * debugging and statistical purposes, but ...
	 * Just take a reference and get out.
	 */
	XFS_QM_HOLD(xfs_Gqm);
	XFS_QM_UNLOCK(xfs_Gqm);

	return 0;
}


/*
 * Release the reference that a filesystem took at mount time,
 * so that we know when we need to destroy the entire quota manager.
 */
/* ARGSUSED */
STATIC void
xfs_qm_rele_quotafs_ref(
	struct xfs_mount *mp)
{
	xfs_dquot_t	*dqp, *nextdqp;

	ASSERT(xfs_Gqm);
	ASSERT(xfs_Gqm->qm_nrefs > 0);

	/*
	 * Go thru the freelist and destroy all inactive dquots.
	 */
	xfs_qm_freelist_lock(xfs_Gqm);

	for (dqp = xfs_Gqm->qm_dqfreelist.qh_next;
	     dqp != (xfs_dquot_t *)&(xfs_Gqm->qm_dqfreelist); ) {
		xfs_dqlock(dqp);
		nextdqp = dqp->dq_flnext;
		if (dqp->dq_flags & XFS_DQ_INACTIVE) {
			ASSERT(dqp->q_mount == NULL);
			ASSERT(! XFS_DQ_IS_DIRTY(dqp));
			ASSERT(dqp->HL_PREVP == NULL);
			ASSERT(dqp->MPL_PREVP == NULL);
			XQM_FREELIST_REMOVE(dqp);
			xfs_dqunlock(dqp);
			xfs_qm_dqdestroy(dqp);
		} else {
			xfs_dqunlock(dqp);
		}
		dqp = nextdqp;
	}
	xfs_qm_freelist_unlock(xfs_Gqm);

	/*
	 * Destroy the entire XQM. If somebody mounts with quotaon, this'll
	 * be restarted.
	 */
	XFS_QM_LOCK(xfs_Gqm);
	XFS_QM_RELE(xfs_Gqm);
	if (xfs_Gqm->qm_nrefs == 0) {
		xfs_qm_destroy(xfs_Gqm);
		xfs_Gqm = NULL;
	}
	XFS_QM_UNLOCK(xfs_Gqm);
}

/*
 * This is called at mount time from xfs_mountfs to initialize the quotainfo
 * structure and start the global quotamanager (xfs_Gqm) if it hasn't done
 * so already.	Note that the superblock has not been read in yet.
 */
void
xfs_qm_mount_quotainit(
	xfs_mount_t	*mp,
	uint		flags)
{
	/*
	 * User, projects or group quotas has to be on.
	 */
	ASSERT(flags & (XFSMNT_UQUOTA | XFSMNT_PQUOTA | XFSMNT_GQUOTA));

	/*
	 * Initialize the flags in the mount structure. From this point
	 * onwards we look at m_qflags to figure out if quotas's ON/OFF, etc.
	 * Note that we enforce nothing if accounting is off.
	 * ie.	XFSMNT_*QUOTA must be ON for XFSMNT_*QUOTAENF.
	 * It isn't necessary to take the quotaoff lock to do this; this is
	 * called from mount.
	 */
	if (flags & XFSMNT_UQUOTA) {
		mp->m_qflags |= (XFS_UQUOTA_ACCT | XFS_UQUOTA_ACTIVE);
		if (flags & XFSMNT_UQUOTAENF)
			mp->m_qflags |= XFS_UQUOTA_ENFD;
	}
	if (flags & XFSMNT_GQUOTA) {
		mp->m_qflags |= (XFS_GQUOTA_ACCT | XFS_GQUOTA_ACTIVE);
		if (flags & XFSMNT_GQUOTAENF)
			mp->m_qflags |= XFS_OQUOTA_ENFD;
	} else if (flags & XFSMNT_PQUOTA) {
		mp->m_qflags |= (XFS_PQUOTA_ACCT | XFS_PQUOTA_ACTIVE);
		if (flags & XFSMNT_PQUOTAENF)
			mp->m_qflags |= XFS_OQUOTA_ENFD;
	}
}

/*
 * Just destroy the quotainfo structure.
 */
void
xfs_qm_unmount_quotadestroy(
	xfs_mount_t	*mp)
{
	if (mp->m_quotainfo)
		xfs_qm_destroy_quotainfo(mp);
}


/*
 * This is called from xfs_mountfs to start quotas and initialize all
 * necessary data structures like quotainfo.  This is also responsible for
 * running a quotacheck as necessary.  We are guaranteed that the superblock
 * is consistently read in at this point.
 */
int
xfs_qm_mount_quotas(
	xfs_mount_t	*mp,
	int		mfsi_flags)
{
	unsigned long	s;
	int		error = 0;
	uint		sbf;


	/*
	 * If quotas on realtime volumes is not supported, we disable
	 * quotas immediately.
	 */
	if (mp->m_sb.sb_rextents) {
		cmn_err(CE_NOTE,
			"Cannot turn on quotas for realtime filesystem %s",
			mp->m_fsname);
		mp->m_qflags = 0;
		goto write_changes;
	}

	ASSERT(XFS_IS_QUOTA_RUNNING(mp));

	/*
	 * Allocate the quotainfo structure inside the mount struct, and
	 * create quotainode(s), and change/rev superblock if necessary.
	 */
	if ((error = xfs_qm_init_quotainfo(mp))) {
		/*
		 * We must turn off quotas.
		 */
		ASSERT(mp->m_quotainfo == NULL);
		mp->m_qflags = 0;
		goto write_changes;
	}
	/*
	 * If any of the quotas are not consistent, do a quotacheck.
	 */
	if (XFS_QM_NEED_QUOTACHECK(mp) &&
		!(mfsi_flags & XFS_MFSI_NO_QUOTACHECK)) {
		if ((error = xfs_qm_quotacheck(mp))) {
			/* Quotacheck has failed and quotas have
			 * been disabled.
			 */
			return XFS_ERROR(error);
		}
	}

 write_changes:
	/*
	 * We actually don't have to acquire the SB_LOCK at all.
	 * This can only be called from mount, and that's single threaded. XXX
	 */
	s = XFS_SB_LOCK(mp);
	sbf = mp->m_sb.sb_qflags;
	mp->m_sb.sb_qflags = mp->m_qflags & XFS_MOUNT_QUOTA_ALL;
	XFS_SB_UNLOCK(mp, s);

	if (sbf != (mp->m_qflags & XFS_MOUNT_QUOTA_ALL)) {
		if (xfs_qm_write_sb_changes(mp, XFS_SB_QFLAGS)) {
			/*
			 * We could only have been turning quotas off.
			 * We aren't in very good shape actually because
			 * the incore structures are convinced that quotas are
			 * off, but the on disk superblock doesn't know that !
			 */
			ASSERT(!(XFS_IS_QUOTA_RUNNING(mp)));
			xfs_fs_cmn_err(CE_ALERT, mp,
				"XFS mount_quotas: Superblock update failed!");
		}
	}

	if (error) {
		xfs_fs_cmn_err(CE_WARN, mp,
			"Failed to initialize disk quotas.");
	}
	return XFS_ERROR(error);
}

/*
 * Called from the vfsops layer.
 */
int
xfs_qm_unmount_quotas(
	xfs_mount_t	*mp)
{
	xfs_inode_t	*uqp, *gqp;
	int		error = 0;

	/*
	 * Release the dquots that root inode, et al might be holding,
	 * before we flush quotas and blow away the quotainfo structure.
	 */
	ASSERT(mp->m_rootip);
	xfs_qm_dqdetach(mp->m_rootip);
	if (mp->m_rbmip)
		xfs_qm_dqdetach(mp->m_rbmip);
	if (mp->m_rsumip)
		xfs_qm_dqdetach(mp->m_rsumip);

	/*
	 * Flush out the quota inodes.
	 */
	uqp = gqp = NULL;
	if (mp->m_quotainfo) {
		if ((uqp = mp->m_quotainfo->qi_uquotaip) != NULL) {
			xfs_ilock(uqp, XFS_ILOCK_EXCL);
			xfs_iflock(uqp);
			error = xfs_iflush(uqp, XFS_IFLUSH_SYNC);
			xfs_iunlock(uqp, XFS_ILOCK_EXCL);
			if (unlikely(error == EFSCORRUPTED)) {
				XFS_ERROR_REPORT("xfs_qm_unmount_quotas(1)",
						 XFS_ERRLEVEL_LOW, mp);
				goto out;
			}
		}
		if ((gqp = mp->m_quotainfo->qi_gquotaip) != NULL) {
			xfs_ilock(gqp, XFS_ILOCK_EXCL);
			xfs_iflock(gqp);
			error = xfs_iflush(gqp, XFS_IFLUSH_SYNC);
			xfs_iunlock(gqp, XFS_ILOCK_EXCL);
			if (unlikely(error == EFSCORRUPTED)) {
				XFS_ERROR_REPORT("xfs_qm_unmount_quotas(2)",
						 XFS_ERRLEVEL_LOW, mp);
				goto out;
			}
		}
	}
	if (uqp) {
		 XFS_PURGE_INODE(uqp);
		 mp->m_quotainfo->qi_uquotaip = NULL;
	}
	if (gqp) {
		XFS_PURGE_INODE(gqp);
		mp->m_quotainfo->qi_gquotaip = NULL;
	}
out:
	return XFS_ERROR(error);
}

/*
 * Flush all dquots of the given file system to disk. The dquots are
 * _not_ purged from memory here, just their data written to disk.
 */
STATIC int
xfs_qm_dqflush_all(
	xfs_mount_t	*mp,
	int		flags)
{
	int		recl;
	xfs_dquot_t	*dqp;
	int		niters;
	int		error;

	if (mp->m_quotainfo == NULL)
		return (0);
	niters = 0;
again:
	xfs_qm_mplist_lock(mp);
	FOREACH_DQUOT_IN_MP(dqp, mp) {
		xfs_dqlock(dqp);
		if (! XFS_DQ_IS_DIRTY(dqp)) {
			xfs_dqunlock(dqp);
			continue;
		}
		xfs_dqtrace_entry(dqp, "FLUSHALL: DQDIRTY");
		/* XXX a sentinel would be better */
		recl = XFS_QI_MPLRECLAIMS(mp);
		if (! xfs_qm_dqflock_nowait(dqp)) {
			/*
			 * If we can't grab the flush lock then 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.
			 */
			xfs_qm_dqflock_pushbuf_wait(dqp);
		}
		/*
		 * Let go of the mplist lock. We don't want to hold it
		 * across a disk write.
		 */
		xfs_qm_mplist_unlock(mp);
		error = xfs_qm_dqflush(dqp, flags);
		xfs_dqunlock(dqp);
		if (error)
			return (error);

		xfs_qm_mplist_lock(mp);
		if (recl != XFS_QI_MPLRECLAIMS(mp)) {
			xfs_qm_mplist_unlock(mp);
			/* XXX restart limit */
			goto again;
		}
	}

	xfs_qm_mplist_unlock(mp);
	/* return ! busy */
	return (0);
}
/*
 * Release the group dquot pointers the user dquots may be
 * carrying around as a hint. mplist is locked on entry and exit.
 */
STATIC void
xfs_qm_detach_gdquots(
	xfs_mount_t	*mp)
{
	xfs_dquot_t	*dqp, *gdqp;
	int		nrecl;

 again:
	ASSERT(XFS_QM_IS_MPLIST_LOCKED(mp));
	dqp = XFS_QI_MPLNEXT(mp);
	while (dqp) {
		xfs_dqlock(dqp);
		if ((gdqp = dqp->q_gdquot)) {
			xfs_dqlock(gdqp);
			dqp->q_gdquot = NULL;
		}
		xfs_dqunlock(dqp);

		if (gdqp) {
			/*
			 * Can't hold the mplist lock across a dqput.
			 * XXXmust convert to marker based iterations here.
			 */
			nrecl = XFS_QI_MPLRECLAIMS(mp);
			xfs_qm_mplist_unlock(mp);
			xfs_qm_dqput(gdqp);

			xfs_qm_mplist_lock(mp);
			if (nrecl != XFS_QI_MPLRECLAIMS(mp))
				goto again;
		}
		dqp = dqp->MPL_NEXT;
	}
}

/*
 * Go through all the incore dquots of this file system and take them
 * off the mplist and hashlist, if the dquot type matches the dqtype
 * parameter. This is used when turning off quota accounting for
 * users and/or groups, as well as when the filesystem is unmounting.
 */
STATIC int
xfs_qm_dqpurge_int(
	xfs_mount_t	*mp,
	uint		flags) /* QUOTAOFF/UMOUNTING/UQUOTA/PQUOTA/GQUOTA */
{
	xfs_dquot_t	*dqp;
	uint		dqtype;
	int		nrecl;
	xfs_dquot_t	*nextdqp;
	int		nmisses;

	if (mp->m_quotainfo == NULL)
		return (0);

	dqtype = (flags & XFS_QMOPT_UQUOTA) ? XFS_DQ_USER : 0;
	dqtype |= (flags & XFS_QMOPT_PQUOTA) ? XFS_DQ_PROJ : 0;
	dqtype |= (flags & XFS_QMOPT_GQUOTA) ? XFS_DQ_GROUP : 0;

	xfs_qm_mplist_lock(mp);

	/*
	 * In the first pass through all incore dquots of this filesystem,
	 * we release the group dquot pointers the user dquots may be
	 * carrying around as a hint. We need to do this irrespective of
	 * what's being turned off.
	 */
	xfs_qm_detach_gdquots(mp);

      again:
	nmisses = 0;
	ASSERT(XFS_QM_IS_MPLIST_LOCKED(mp));
	/*
	 * Try to get rid of all of the unwanted dquots. The idea is to
	 * get them off mplist and hashlist, but leave them on freelist.
	 */
	dqp = XFS_QI_MPLNEXT(mp);
	while (dqp) {
		/*
		 * It's OK to look at the type without taking dqlock here.
		 * We're holding the mplist lock here, and that's needed for
		 * a dqreclaim.
		 */
		if ((dqp->dq_flags & dqtype) == 0) {
			dqp = dqp->MPL_NEXT;
			continue;
		}

		if (! xfs_qm_dqhashlock_nowait(dqp)) {
			nrecl = XFS_QI_MPLRECLAIMS(mp);
			xfs_qm_mplist_unlock(mp);
			XFS_DQ_HASH_LOCK(dqp->q_hash);
			xfs_qm_mplist_lock(mp);

			/*
			 * XXXTheoretically, we can get into a very long
			 * ping pong game here.
			 * No one can be adding dquots to the mplist at
			 * this point, but somebody might be taking things off.
			 */
			if (nrecl != XFS_QI_MPLRECLAIMS(mp)) {
				XFS_DQ_HASH_UNLOCK(dqp->q_hash);
				goto again;
			}
		}

		/*
		 * Take the dquot off the mplist and hashlist. It may remain on
		 * freelist in INACTIVE state.
		 */
		nextdqp = dqp->MPL_NEXT;
		nmisses += xfs_qm_dqpurge(dqp, flags);
		dqp = nextdqp;
	}
	xfs_qm_mplist_unlock(mp);
	return nmisses;
}

int
xfs_qm_dqpurge_all(
	xfs_mount_t	*mp,
	uint		flags)
{
	int		ndquots;

	/*
	 * Purge the dquot cache.
	 * None of the dquots should really be busy at this point.
	 */
	if (mp->m_quotainfo) {
		while ((ndquots = xfs_qm_dqpurge_int(mp, flags))) {
			delay(ndquots * 10);
		}
	}
	return 0;
}

STATIC int
xfs_qm_dqattach_one(
	xfs_inode_t	*ip,
	xfs_dqid_t	id,
	uint		type,
	uint		doalloc,
	uint		dolock,
	xfs_dquot_t	*udqhint, /* hint */
	xfs_dquot_t	**IO_idqpp)
{
	xfs_dquot_t	*dqp;
	int		error;

	ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
	error = 0;
	/*
	 * See if we already have it in the inode itself. IO_idqpp is
	 * &i_udquot or &i_gdquot. This made the code look weird, but
	 * made the logic a lot simpler.
	 */
	if ((dqp = *IO_idqpp)) {
		if (dolock)
			xfs_dqlock(dqp);
		xfs_dqtrace_entry(dqp, "DQATTACH: found in ip");
		goto done;
	}

	/*
	 * udqhint is the i_udquot field in inode, and is non-NULL only
	 * when the type arg is group/project. Its purpose is to save a
	 * lookup by dqid (xfs_qm_dqget) by caching a group dquot inside
	 * the user dquot.
	 */
	ASSERT(!udqhint || type == XFS_DQ_GROUP || type == XFS_DQ_PROJ);
	if (udqhint && !dolock)
		xfs_dqlock(udqhint);

	/*
	 * No need to take dqlock to look at the id.
	 * The ID can't change until it gets reclaimed, and it won't
	 * be reclaimed as long as we have a ref from inode and we hold
	 * the ilock.
	 */
	if (udqhint &&
	    (dqp = udqhint->q_gdquot) &&
	    (INT_GET(dqp->q_core.d_id, ARCH_CONVERT) == id)) {
		ASSERT(XFS_DQ_IS_LOCKED(udqhint));
		xfs_dqlock(dqp);
		XFS_DQHOLD(dqp);
		ASSERT(*IO_idqpp == NULL);
		*IO_idqpp = dqp;
		if (!dolock) {
			xfs_dqunlock(dqp);
			xfs_dqunlock(udqhint);
		}
		goto done;
	}
	/*
	 * We can't hold a dquot lock when we call the dqget code.
	 * We'll deadlock in no time, because of (not conforming to)
	 * lock ordering - the inodelock comes before any dquot lock,
	 * and we may drop and reacquire the ilock in xfs_qm_dqget().
	 */
	if (udqhint)
		xfs_dqunlock(udqhint);
	/*
	 * Find the dquot from somewhere. This bumps the
	 * reference count of dquot and returns it locked.
	 * This can return ENOENT if dquot didn't exist on
	 * disk and we didn't ask it to allocate;
	 * ESRCH if quotas got turned off suddenly.
	 */
	if ((error = xfs_qm_dqget(ip->i_mount, ip, id, type,
				 doalloc|XFS_QMOPT_DOWARN, &dqp))) {
		if (udqhint && dolock)
			xfs_dqlock(udqhint);
		goto done;
	}

	xfs_dqtrace_entry(dqp, "DQATTACH: found by dqget");
	/*
	 * dqget may have dropped and re-acquired the ilock, but it guarantees
	 * that the dquot returned is the one that should go in the inode.
	 */
	*IO_idqpp = dqp;
	ASSERT(dqp);
	ASSERT(XFS_DQ_IS_LOCKED(dqp));
	if (! dolock) {
		xfs_dqunlock(dqp);
		goto done;
	}
	if (! udqhint)
		goto done;

	ASSERT(udqhint);
	ASSERT(dolock);
	ASSERT(XFS_DQ_IS_LOCKED(dqp));
	if (! xfs_qm_dqlock_nowait(udqhint)) {
		xfs_dqunlock(dqp);
		xfs_dqlock(udqhint);
		xfs_dqlock(dqp);
	}
      done:
#ifdef QUOTADEBUG
	if (udqhint) {
		if (dolock)
			ASSERT(XFS_DQ_IS_LOCKED(udqhint));
	}
	if (! error) {
		if (dolock)
			ASSERT(XFS_DQ_IS_LOCKED(dqp));
	}
#endif
	return (error);
}


/*
 * Given a udquot and gdquot, attach a ptr to the group dquot in the
 * udquot as a hint for future lookups. The idea sounds simple, but the
 * execution isn't, because the udquot might have a group dquot attached
 * already and getting rid of that gets us into lock ordering contraints.
 * The process is complicated more by the fact that the dquots may or may not
 * be locked on entry.
 */
STATIC void
xfs_qm_dqattach_grouphint(
	xfs_dquot_t	*udq,
	xfs_dquot_t	*gdq,
	uint		locked)
{
	xfs_dquot_t	*tmp;

#ifdef QUOTADEBUG
	if (locked) {
		ASSERT(XFS_DQ_IS_LOCKED(udq));
		ASSERT(XFS_DQ_IS_LOCKED(gdq));
	}
#endif
	if (! locked)
		xfs_dqlock(udq);

	if ((tmp = udq->q_gdquot)) {
		if (tmp == gdq) {
			if (! locked)
				xfs_dqunlock(udq);
			return;
		}

		udq->q_gdquot = NULL;
		/*
		 * We can't keep any dqlocks when calling dqrele,
		 * because the freelist lock comes before dqlocks.
		 */
		xfs_dqunlock(udq);
		if (locked)
			xfs_dqunlock(gdq);
		/*
		 * we took a hard reference once upon a time in dqget,
		 * so give it back when the udquot no longer points at it
		 * dqput() does the unlocking of the dquot.
		 */
		xfs_qm_dqrele(tmp);

		xfs_dqlock(udq);
		xfs_dqlock(gdq);

	} else {
		ASSERT(XFS_DQ_IS_LOCKED(udq));
		if (! locked) {
			xfs_dqlock(gdq);
		}
	}

	ASSERT(XFS_DQ_IS_LOCKED(udq));
	ASSERT(XFS_DQ_IS_LOCKED(gdq));
	/*
	 * Somebody could have attached a gdquot here,
	 * when we dropped the uqlock. If so, just do nothing.
	 */
	if (udq->q_gdquot == NULL) {
		XFS_DQHOLD(gdq);
		udq->q_gdquot = gdq;
	}
	if (! locked) {
		xfs_dqunlock(gdq);
		xfs_dqunlock(udq);
	}
}


/*
 * Given a locked inode, attach dquot(s) to it, taking U/G/P-QUOTAON
 * into account.
 * If XFS_QMOPT_DQALLOC, the dquot(s) will be allocated if needed.
 * If XFS_QMOPT_DQLOCK, the dquot(s) will be returned locked. This option pretty
 * much made this code a complete mess, but it has been pretty useful.
 * If XFS_QMOPT_ILOCKED, then inode sent is already locked EXCL.
 * Inode may get unlocked and relocked in here, and the caller must deal with
 * the consequences.
 */
int
xfs_qm_dqattach(
	xfs_inode_t	*ip,
	uint		flags)
{
	xfs_mount_t	*mp = ip->i_mount;
	uint		nquotas = 0;
	int		error = 0;

	if ((! XFS_IS_QUOTA_ON(mp)) ||
	    (! XFS_NOT_DQATTACHED(mp, ip)) ||
	    (ip->i_ino == mp->m_sb.sb_uquotino) ||
	    (ip->i_ino == mp->m_sb.sb_gquotino))
		return (0);

	ASSERT((flags & XFS_QMOPT_ILOCKED) == 0 ||
	       XFS_ISLOCKED_INODE_EXCL(ip));

	if (! (flags & XFS_QMOPT_ILOCKED))
		xfs_ilock(ip, XFS_ILOCK_EXCL);

	if (XFS_IS_UQUOTA_ON(mp)) {
		error = xfs_qm_dqattach_one(ip, ip->i_d.di_uid, XFS_DQ_USER,
						flags & XFS_QMOPT_DQALLOC,
						flags & XFS_QMOPT_DQLOCK,
						NULL, &ip->i_udquot);
		if (error)
			goto done;
		nquotas++;
	}
	ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
	if (XFS_IS_OQUOTA_ON(mp)) {
		error = XFS_IS_GQUOTA_ON(mp) ?
			xfs_qm_dqattach_one(ip, ip->i_d.di_gid, XFS_DQ_GROUP,
						flags & XFS_QMOPT_DQALLOC,
						flags & XFS_QMOPT_DQLOCK,
						ip->i_udquot, &ip->i_gdquot) :
			xfs_qm_dqattach_one(ip, ip->i_d.di_projid, XFS_DQ_PROJ,
						flags & XFS_QMOPT_DQALLOC,
						flags & XFS_QMOPT_DQLOCK,
						ip->i_udquot, &ip->i_gdquot);
		/*
		 * Don't worry about the udquot that we may have
		 * attached above. It'll get detached, if not already.
		 */
		if (error)
			goto done;
		nquotas++;
	}

	/*
	 * Attach this group quota to the user quota as a hint.
	 * This WON'T, in general, result in a thrash.
	 */
	if (nquotas == 2) {
		ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
		ASSERT(ip->i_udquot);
		ASSERT(ip->i_gdquot);

		/*
		 * We may or may not have the i_udquot locked at this point,
		 * but this check is OK since we don't depend on the i_gdquot to
		 * be accurate 100% all the time. It is just a hint, and this
		 * will succeed in general.
		 */
		if (ip->i_udquot->q_gdquot == ip->i_gdquot)
			goto done;
		/*
		 * Attach i_gdquot to the gdquot hint inside the i_udquot.
		 */
		xfs_qm_dqattach_grouphint(ip->i_udquot, ip->i_gdquot,
					 flags & XFS_QMOPT_DQLOCK);
	}

      done:

#ifdef QUOTADEBUG
	if (! error) {
		if (ip->i_udquot) {
			if (flags & XFS_QMOPT_DQLOCK)
				ASSERT(XFS_DQ_IS_LOCKED(ip->i_udquot));
		}
		if (ip->i_gdquot) {
			if (flags & XFS_QMOPT_DQLOCK)
				ASSERT(XFS_DQ_IS_LOCKED(ip->i_gdquot));
		}
		if (XFS_IS_UQUOTA_ON(mp))
			ASSERT(ip->i_udquot);
		if (XFS_IS_OQUOTA_ON(mp))
			ASSERT(ip->i_gdquot);
	}
#endif

	if (! (flags & XFS_QMOPT_ILOCKED))
		xfs_iunlock(ip, XFS_ILOCK_EXCL);

#ifdef QUOTADEBUG
	else
		ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
#endif
	return (error);
}

/*
 * Release dquots (and their references) if any.
 * The inode should be locked EXCL except when this's called by
 * xfs_ireclaim.
 */
void
xfs_qm_dqdetach(
	xfs_inode_t	*ip)
{
	if (!(ip->i_udquot || ip->i_gdquot))
		return;

	ASSERT(ip->i_ino != ip->i_mount->m_sb.sb_uquotino);
	ASSERT(ip->i_ino != ip->i_mount->m_sb.sb_gquotino);
	if (ip->i_udquot) {
		xfs_dqtrace_entry_ino(ip->i_udquot, "DQDETTACH", ip);
		xfs_qm_dqrele(ip->i_udquot);
		ip->i_udquot = NULL;
	}
	if (ip->i_gdquot) {
		xfs_dqtrace_entry_ino(ip->i_gdquot, "DQDETTACH", ip);
		xfs_qm_dqrele(ip->i_gdquot);
		ip->i_gdquot = NULL;
	}
}

/*
 * This is called by VFS_SYNC and flags arg determines the caller,
 * and its motives, as done in xfs_sync.
 *
 * vfs_sync: SYNC_FSDATA|SYNC_ATTR|SYNC_BDFLUSH 0x31
 * syscall sync: SYNC_FSDATA|SYNC_ATTR|SYNC_DELWRI 0x25
 * umountroot : SYNC_WAIT | SYNC_CLOSE | SYNC_ATTR | SYNC_FSDATA
 */

int
xfs_qm_sync(
	xfs_mount_t	*mp,
	short		flags)
{
	int		recl, restarts;
	xfs_dquot_t	*dqp;
	uint		flush_flags;
	boolean_t	nowait;
	int		error;

	restarts = 0;
	/*
	 * We won't block unless we are asked to.
	 */
	nowait = (boolean_t)(flags & SYNC_BDFLUSH || (flags & SYNC_WAIT) == 0);

  again:
	xfs_qm_mplist_lock(mp);
	/*
	 * dqpurge_all() also takes the mplist lock and iterate thru all dquots
	 * in quotaoff. However, if the QUOTA_ACTIVE bits are not cleared
	 * when we have the mplist lock, we know that dquots will be consistent
	 * as long as we have it locked.
	 */
	if (! XFS_IS_QUOTA_ON(mp)) {
		xfs_qm_mplist_unlock(mp);
		return (0);
	}
	FOREACH_DQUOT_IN_MP(dqp, mp) {
		/*
		 * If this is vfs_sync calling, then skip the dquots that
		 * don't 'seem' to be dirty. ie. don't acquire dqlock.
		 * This is very similar to what xfs_sync does with inodes.
		 */
		if (flags & SYNC_BDFLUSH) {
			if (! XFS_DQ_IS_DIRTY(dqp))
				continue;
		}

		if (nowait) {
			/*
			 * Try to acquire the dquot lock. We are NOT out of
			 * lock order, but we just don't want to wait for this
			 * lock, unless somebody wanted us to.
			 */
			if (! xfs_qm_dqlock_nowait(dqp))
				continue;
		} else {
			xfs_dqlock(dqp);
		}

		/*
		 * Now, find out for sure if this dquot is dirty or not.
		 */
		if (! XFS_DQ_IS_DIRTY(dqp)) {
			xfs_dqunlock(dqp);
			continue;
		}

		/* XXX a sentinel would be better */
		recl = XFS_QI_MPLRECLAIMS(mp);
		if (! xfs_qm_dqflock_nowait(dqp)) {
			if (nowait) {
				xfs_dqunlock(dqp);
				continue;
			}
			/*
			 * If we can't grab the flush lock then if the caller
			 * really wanted us to give this our best shot,
			 * see if we can give a push to the buffer before we wait
			 * on the flush lock. At this point, we know that
			 * eventhough the dquot is being flushed,
			 * it has (new) dirty data.
			 */
			xfs_qm_dqflock_pushbuf_wait(dqp);
		}
		/*
		 * Let go of the mplist lock. We don't want to hold it
		 * across a disk write
		 */
		flush_flags = (nowait) ? XFS_QMOPT_DELWRI : XFS_QMOPT_SYNC;
		xfs_qm_mplist_unlock(mp);
		xfs_dqtrace_entry(dqp, "XQM_SYNC: DQFLUSH");
		error = xfs_qm_dqflush(dqp, flush_flags);
		xfs_dqunlock(dqp);
		if (error && XFS_FORCED_SHUTDOWN(mp))
			return(0);	/* Need to prevent umount failure */
		else if (error)
			return (error);

		xfs_qm_mplist_lock(mp);
		if (recl != XFS_QI_MPLRECLAIMS(mp)) {
			if (++restarts >= XFS_QM_SYNC_MAX_RESTARTS)
				break;

			xfs_qm_mplist_unlock(mp);
			goto again;
		}
	}

	xfs_qm_mplist_unlock(mp);
	return (0);
}


/*
 * This initializes all the quota information that's kept in the
 * mount structure
 */
STATIC int
xfs_qm_init_quotainfo(
	xfs_mount_t	*mp)
{
	xfs_quotainfo_t *qinf;
	int		error;
	xfs_dquot_t	*dqp;

	ASSERT(XFS_IS_QUOTA_RUNNING(mp));

	/*
	 * Tell XQM that we exist as soon as possible.
	 */
	if ((error = xfs_qm_hold_quotafs_ref(mp))) {
		return (error);
	}

	qinf = mp->m_quotainfo = kmem_zalloc(sizeof(xfs_quotainfo_t), KM_SLEEP);

	/*
	 * See if quotainodes are setup, and if not, allocate them,
	 * and change the superblock accordingly.
	 */
	if ((error = xfs_qm_init_quotainos(mp))) {
		kmem_free(qinf, sizeof(xfs_quotainfo_t));
		mp->m_quotainfo = NULL;
		return (error);
	}

	spinlock_init(&qinf->qi_pinlock, "xfs_qinf_pin");
	xfs_qm_list_init(&qinf->qi_dqlist, "mpdqlist", 0);
	qinf->qi_dqreclaims = 0;

	/* mutex used to serialize quotaoffs */
	mutex_init(&qinf->qi_quotaofflock, MUTEX_DEFAULT, "qoff");

	/* Precalc some constants */
	qinf->qi_dqchunklen = XFS_FSB_TO_BB(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
	ASSERT(qinf->qi_dqchunklen);
	qinf->qi_dqperchunk = BBTOB(qinf->qi_dqchunklen);
	do_div(qinf->qi_dqperchunk, sizeof(xfs_dqblk_t));

	mp->m_qflags |= (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_CHKD);

	/*
	 * We try to get the limits from the superuser's limits fields.
	 * This is quite hacky, but it is standard quota practice.
	 * We look at the USR dquot with id == 0 first, but if user quotas
	 * are not enabled we goto the GRP dquot with id == 0.
	 * We don't really care to keep separate default limits for user
	 * and group quotas, at least not at this point.
	 */
	error = xfs_qm_dqget(mp, NULL, (xfs_dqid_t)0,
			     XFS_IS_UQUOTA_RUNNING(mp) ? XFS_DQ_USER : 
			     (XFS_IS_GQUOTA_RUNNING(mp) ? XFS_DQ_GROUP :
				XFS_DQ_PROJ),
			     XFS_QMOPT_DQSUSER|XFS_QMOPT_DOWARN,
			     &dqp);
	if (! error) {
		xfs_disk_dquot_t	*ddqp = &dqp->q_core;

		/*
		 * The warnings and timers set the grace period given to
		 * a user or group before he or she can not perform any
		 * more writing. If it is zero, a default is used.
		 */
		qinf->qi_btimelimit =
				INT_GET(ddqp->d_btimer, ARCH_CONVERT) ?
				INT_GET(ddqp->d_btimer, ARCH_CONVERT) :
				XFS_QM_BTIMELIMIT;
		qinf->qi_itimelimit =
				INT_GET(ddqp->d_itimer, ARCH_CONVERT) ?
				INT_GET(ddqp->d_itimer, ARCH_CONVERT) :
				XFS_QM_ITIMELIMIT;
		qinf->qi_rtbtimelimit =
				INT_GET(ddqp->d_rtbtimer, ARCH_CONVERT) ?
				INT_GET(ddqp->d_rtbtimer, ARCH_CONVERT) :
				XFS_QM_RTBTIMELIMIT;
		qinf->qi_bwarnlimit =
				INT_GET(ddqp->d_bwarns, ARCH_CONVERT) ?
				INT_GET(ddqp->d_bwarns, ARCH_CONVERT) :
				XFS_QM_BWARNLIMIT;
		qinf->qi_iwarnlimit =
				INT_GET(ddqp->d_iwarns, ARCH_CONVERT) ?
				INT_GET(ddqp->d_iwarns, ARCH_CONVERT) :
				XFS_QM_IWARNLIMIT;
		qinf->qi_rtbwarnlimit =
				INT_GET(ddqp->d_rtbwarns, ARCH_CONVERT) ?
				INT_GET(ddqp->d_rtbwarns, ARCH_CONVERT) :
				XFS_QM_RTBWARNLIMIT;
		qinf->qi_bhardlimit =
				INT_GET(ddqp->d_blk_hardlimit, ARCH_CONVERT);
		qinf->qi_bsoftlimit =
				INT_GET(ddqp->d_blk_softlimit, ARCH_CONVERT);
		qinf->qi_ihardlimit =
				INT_GET(ddqp->d_ino_hardlimit, ARCH_CONVERT);
		qinf->qi_isoftlimit =
				INT_GET(ddqp->d_ino_softlimit, ARCH_CONVERT);
		qinf->qi_rtbhardlimit =
				INT_GET(ddqp->d_rtb_hardlimit, ARCH_CONVERT);
		qinf->qi_rtbsoftlimit =
				INT_GET(ddqp->d_rtb_softlimit, ARCH_CONVERT);
 
		/*
		 * We sent the XFS_QMOPT_DQSUSER flag to dqget because
		 * we don't want this dquot cached. We haven't done a
		 * quotacheck yet, and quotacheck doesn't like incore dquots.
		 */
		xfs_qm_dqdestroy(dqp);
	} else {
		qinf->qi_btimelimit = XFS_QM_BTIMELIMIT;
		qinf->qi_itimelimit = XFS_QM_ITIMELIMIT;
		qinf->qi_rtbtimelimit = XFS_QM_RTBTIMELIMIT;
		qinf->qi_bwarnlimit = XFS_QM_BWARNLIMIT;
		qinf->qi_iwarnlimit = XFS_QM_IWARNLIMIT;
		qinf->qi_rtbwarnlimit = XFS_QM_RTBWARNLIMIT;
	}

	return (0);
}


/*
 * Gets called when unmounting a filesystem or when all quotas get
 * turned off.
 * This purges the quota inodes, destroys locks and frees itself.
 */
void
xfs_qm_destroy_quotainfo(
	xfs_mount_t	*mp)
{
	xfs_quotainfo_t *qi;

	qi = mp->m_quotainfo;
	ASSERT(qi != NULL);
	ASSERT(xfs_Gqm != NULL);

	/*
	 * Release the reference that XQM kept, so that we know
	 * when the XQM structure should be freed. We cannot assume
	 * that xfs_Gqm is non-null after this point.
	 */
	xfs_qm_rele_quotafs_ref(mp);

	spinlock_destroy(&qi->qi_pinlock);
	xfs_qm_list_destroy(&qi->qi_dqlist);

	if (qi->qi_uquotaip) {
		XFS_PURGE_INODE(qi->qi_uquotaip);
		qi->qi_uquotaip = NULL; /* paranoia */
	}
	if (qi->qi_gquotaip) {
		XFS_PURGE_INODE(qi->qi_gquotaip);
		qi->qi_gquotaip = NULL;
	}
	mutex_destroy(&qi->qi_quotaofflock);
	kmem_free(qi, sizeof(xfs_quotainfo_t));
	mp->m_quotainfo = NULL;
}



/* ------------------- PRIVATE STATIC FUNCTIONS ----------------------- */

/* ARGSUSED */
STATIC void
xfs_qm_list_init(
	xfs_dqlist_t	*list,
	char		*str,
	int		n)
{
	mutex_init(&list->qh_lock, MUTEX_DEFAULT, str);
	list->qh_next = NULL;
	list->qh_version = 0;
	list->qh_nelems = 0;
}

STATIC void
xfs_qm_list_destroy(
	xfs_dqlist_t	*list)
{
	mutex_destroy(&(list->qh_lock));
}


/*
 * Stripped down version of dqattach. This doesn't attach, or even look at the
 * dquots attached to the inode. The rationale is that there won't be any
 * attached at the time this is called from quotacheck.
 */
STATIC int
xfs_qm_dqget_noattach(
	xfs_inode_t	*ip,
	xfs_dquot_t	**O_udqpp,
	xfs_dquot_t	**O_gdqpp)
{
	int		error;
	xfs_mount_t	*mp;
	xfs_dquot_t	*udqp, *gdqp;

	ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
	mp = ip->i_mount;
	udqp = NULL;
	gdqp = NULL;

	if (XFS_IS_UQUOTA_ON(mp)) {
		ASSERT(ip->i_udquot == NULL);
		/*
		 * We want the dquot allocated if it doesn't exist.
		 */
		if ((error = xfs_qm_dqget(mp, ip, ip->i_d.di_uid, XFS_DQ_USER,
					 XFS_QMOPT_DQALLOC | XFS_QMOPT_DOWARN,
					 &udqp))) {
			/*
			 * Shouldn't be able to turn off quotas here.
			 */
			ASSERT(error != ESRCH);
			ASSERT(error != ENOENT);
			return (error);
		}
		ASSERT(udqp);
	}

	if (XFS_IS_OQUOTA_ON(mp)) {
		ASSERT(ip->i_gdquot == NULL);
		if (udqp)
			xfs_dqunlock(udqp);
		error = XFS_IS_GQUOTA_ON(mp) ?
				xfs_qm_dqget(mp, ip,
					     ip->i_d.di_gid, XFS_DQ_GROUP,
					     XFS_QMOPT_DQALLOC|XFS_QMOPT_DOWARN,
					     &gdqp) :
				xfs_qm_dqget(mp, ip,
					     ip->i_d.di_projid, XFS_DQ_PROJ,
					     XFS_QMOPT_DQALLOC|XFS_QMOPT_DOWARN,
					     &gdqp);
		if (error) {
			if (udqp)
				xfs_qm_dqrele(udqp);
			ASSERT(error != ESRCH);
			ASSERT(error != ENOENT);
			return (error);
		}
		ASSERT(gdqp);

		/* Reacquire the locks in the right order */
		if (udqp) {
			if (! xfs_qm_dqlock_nowait(udqp)) {
				xfs_dqunlock(gdqp);
				xfs_dqlock(udqp);
				xfs_dqlock(gdqp);
			}
		}
	}

	*O_udqpp = udqp;
	*O_gdqpp = gdqp;

#ifdef QUOTADEBUG
	if (udqp) ASSERT(XFS_DQ_IS_LOCKED(udqp));
	if (gdqp) ASSERT(XFS_DQ_IS_LOCKED(gdqp));
#endif
	return (0);
}

/*
 * Create an inode and return with a reference already taken, but unlocked
 * This is how we create quota inodes
 */
STATIC int
xfs_qm_qino_alloc(
	xfs_mount_t	*mp,
	xfs_inode_t	**ip,
	__int64_t	sbfields,
	uint		flags)
{
	xfs_trans_t	*tp;
	int		error;
	unsigned long s;
	cred_t		zerocr;
	int		committed;

	tp = xfs_trans_alloc(mp,XFS_TRANS_QM_QINOCREATE);
	if ((error = xfs_trans_reserve(tp,
				      XFS_QM_QINOCREATE_SPACE_RES(mp),
				      XFS_CREATE_LOG_RES(mp), 0,
				      XFS_TRANS_PERM_LOG_RES,
				      XFS_CREATE_LOG_COUNT))) {
		xfs_trans_cancel(tp, 0);
		return (error);
	}
	memset(&zerocr, 0, sizeof(zerocr));

	if ((error = xfs_dir_ialloc(&tp, mp->m_rootip, S_IFREG, 1, 0,
				   &zerocr, 0, 1, ip, &committed))) {
		xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES |
				 XFS_TRANS_ABORT);
		return (error);
	}

	/*
	 * Keep an extra reference to this quota inode. This inode is
	 * locked exclusively and joined to the transaction already.
	 */
	ASSERT(XFS_ISLOCKED_INODE_EXCL(*ip));
	VN_HOLD(XFS_ITOV((*ip)));

	/*
	 * Make the changes in the superblock, and log those too.
	 * sbfields arg may contain fields other than *QUOTINO;
	 * VERSIONNUM for example.
	 */
	s = XFS_SB_LOCK(mp);
	if (flags & XFS_QMOPT_SBVERSION) {
#if defined(DEBUG) && defined(XFS_LOUD_RECOVERY)
		unsigned oldv = mp->m_sb.sb_versionnum;
#endif
		ASSERT(!XFS_SB_VERSION_HASQUOTA(&mp->m_sb));
		ASSERT((sbfields & (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
				   XFS_SB_GQUOTINO | XFS_SB_QFLAGS)) ==
		       (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
			XFS_SB_GQUOTINO | XFS_SB_QFLAGS));

		XFS_SB_VERSION_ADDQUOTA(&mp->m_sb);
		mp->m_sb.sb_uquotino = NULLFSINO;
		mp->m_sb.sb_gquotino = NULLFSINO;

		/* qflags will get updated _after_ quotacheck */
		mp->m_sb.sb_qflags = 0;
#if defined(DEBUG) && defined(XFS_LOUD_RECOVERY)
		cmn_err(CE_NOTE,
			"Old superblock version %x, converting to %x.",
			oldv, mp->m_sb.sb_versionnum);
#endif
	}
	if (flags & XFS_QMOPT_UQUOTA)
		mp->m_sb.sb_uquotino = (*ip)->i_ino;
	else
		mp->m_sb.sb_gquotino = (*ip)->i_ino;
	XFS_SB_UNLOCK(mp, s);
	xfs_mod_sb(tp, sbfields);

	if ((error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES,
				     NULL))) {
		xfs_fs_cmn_err(CE_ALERT, mp, "XFS qino_alloc failed!");
		return (error);
	}
	return (0);
}


STATIC int
xfs_qm_reset_dqcounts(
	xfs_mount_t	*mp,
	xfs_buf_t	*bp,
	xfs_dqid_t	id,
	uint		type)
{
	xfs_disk_dquot_t	*ddq;
	int			j;

	xfs_buftrace("RESET DQUOTS", bp);
	/*
	 * Reset all counters and timers. They'll be
	 * started afresh by xfs_qm_quotacheck.
	 */
#ifdef DEBUG
	j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
	do_div(j, sizeof(xfs_dqblk_t));
	ASSERT(XFS_QM_DQPERBLK(mp) == j);
#endif
	ddq = (xfs_disk_dquot_t *)XFS_BUF_PTR(bp);
	for (j = 0; j < XFS_QM_DQPERBLK(mp); j++) {
		/*
		 * Do a sanity check, and if needed, repair the dqblk. Don't
		 * output any warnings because it's perfectly possible to
		 * find unitialized dquot blks. See comment in xfs_qm_dqcheck.
		 */
		(void) xfs_qm_dqcheck(ddq, id+j, type, XFS_QMOPT_DQREPAIR,
				      "xfs_quotacheck");
		INT_SET(ddq->d_bcount, ARCH_CONVERT, 0ULL);
		INT_SET(ddq->d_icount, ARCH_CONVERT, 0ULL);
		INT_SET(ddq->d_rtbcount, ARCH_CONVERT, 0ULL);
		INT_SET(ddq->d_btimer, ARCH_CONVERT, (time_t)0);
		INT_SET(ddq->d_itimer, ARCH_CONVERT, (time_t)0);
		INT_SET(ddq->d_rtbtimer, ARCH_CONVERT, (time_t)0);
		INT_SET(ddq->d_bwarns, ARCH_CONVERT, 0UL);
		INT_SET(ddq->d_iwarns, ARCH_CONVERT, 0UL);
		INT_SET(ddq->d_rtbwarns, ARCH_CONVERT, 0UL);
		ddq = (xfs_disk_dquot_t *) ((xfs_dqblk_t *)ddq + 1);
	}

	return (0);
}

STATIC int
xfs_qm_dqiter_bufs(
	xfs_mount_t	*mp,
	xfs_dqid_t	firstid,
	xfs_fsblock_t	bno,
	xfs_filblks_t	blkcnt,
	uint		flags)
{
	xfs_buf_t	*bp;
	int		error;
	int		notcommitted;
	int		incr;
	int		type;

	ASSERT(blkcnt > 0);
	notcommitted = 0;
	incr = (blkcnt > XFS_QM_MAX_DQCLUSTER_LOGSZ) ?
		XFS_QM_MAX_DQCLUSTER_LOGSZ : blkcnt;
	type = flags & XFS_QMOPT_UQUOTA ? XFS_DQ_USER :
		(flags & XFS_QMOPT_PQUOTA ? XFS_DQ_PROJ : XFS_DQ_GROUP);
	error = 0;

	/*
	 * Blkcnt arg can be a very big number, and might even be
	 * larger than the log itself. So, we have to break it up into
	 * manageable-sized transactions.
	 * Note that we don't start a permanent transaction here; we might
	 * not be able to get a log reservation for the whole thing up front,
	 * and we don't really care to either, because we just discard
	 * everything if we were to crash in the middle of this loop.
	 */
	while (blkcnt--) {
		error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
			      XFS_FSB_TO_DADDR(mp, bno),
			      (int)XFS_QI_DQCHUNKLEN(mp), 0, &bp);
		if (error)
			break;

		(void) xfs_qm_reset_dqcounts(mp, bp, firstid, type);
		xfs_bdwrite(mp, bp);
		/*
		 * goto the next block.
		 */
		bno++;
		firstid += XFS_QM_DQPERBLK(mp);
	}
	return (error);
}

/*
 * Iterate over all allocated USR/GRP/PRJ dquots in the system, calling a
 * caller supplied function for every chunk of dquots that we find.
 */
STATIC int
xfs_qm_dqiterate(
	xfs_mount_t	*mp,
	xfs_inode_t	*qip,
	uint		flags)
{
	xfs_bmbt_irec_t		*map;
	int			i, nmaps;	/* number of map entries */
	int			error;		/* return value */
	xfs_fileoff_t		lblkno;
	xfs_filblks_t		maxlblkcnt;
	xfs_dqid_t		firstid;
	xfs_fsblock_t		rablkno;
	xfs_filblks_t		rablkcnt;

	error = 0;
	/*
	 * This looks racey, but we can't keep an inode lock across a
	 * trans_reserve. But, this gets called during quotacheck, and that
	 * happens only at mount time which is single threaded.
	 */
	if (qip->i_d.di_nblocks == 0)
		return (0);

	map = kmem_alloc(XFS_DQITER_MAP_SIZE * sizeof(*map), KM_SLEEP);

	lblkno = 0;
	maxlblkcnt = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
	do {
		nmaps = XFS_DQITER_MAP_SIZE;
		/*
		 * We aren't changing the inode itself. Just changing
		 * some of its data. No new blocks are added here, and
		 * the inode is never added to the transaction.
		 */
		xfs_ilock(qip, XFS_ILOCK_SHARED);
		error = xfs_bmapi(NULL, qip, lblkno,
				  maxlblkcnt - lblkno,
				  XFS_BMAPI_METADATA,
				  NULL,
				  0, map, &nmaps, NULL);
		xfs_iunlock(qip, XFS_ILOCK_SHARED);
		if (error)
			break;

		ASSERT(nmaps <= XFS_DQITER_MAP_SIZE);
		for (i = 0; i < nmaps; i++) {
			ASSERT(map[i].br_startblock != DELAYSTARTBLOCK);
			ASSERT(map[i].br_blockcount);


			lblkno += map[i].br_blockcount;

			if (map[i].br_startblock == HOLESTARTBLOCK)
				continue;

			firstid = (xfs_dqid_t) map[i].br_startoff *
				XFS_QM_DQPERBLK(mp);
			/*
			 * Do a read-ahead on the next extent.
			 */
			if ((i+1 < nmaps) &&
			    (map[i+1].br_startblock != HOLESTARTBLOCK)) {
				rablkcnt =  map[i+1].br_blockcount;
				rablkno = map[i+1].br_startblock;
				while (rablkcnt--) {
					xfs_baread(mp->m_ddev_targp,
					       XFS_FSB_TO_DADDR(mp, rablkno),
					       (int)XFS_QI_DQCHUNKLEN(mp));
					rablkno++;
				}
			}
			/*
			 * Iterate thru all the blks in the extent and
			 * reset the counters of all the dquots inside them.
			 */
			if ((error = xfs_qm_dqiter_bufs(mp,
						       firstid,
						       map[i].br_startblock,
						       map[i].br_blockcount,
						       flags))) {
				break;
			}
		}

		if (error)
			break;
	} while (nmaps > 0);

	kmem_free(map, XFS_DQITER_MAP_SIZE * sizeof(*map));

	return (error);
}

/*
 * Called by dqusage_adjust in doing a quotacheck.
 * Given the inode, and a dquot (either USR or GRP, doesn't matter),
 * this updates its incore copy as well as the buffer copy. This is
 * so that once the quotacheck is done, we can just log all the buffers,
 * as opposed to logging numerous updates to individual dquots.
 */
STATIC void
xfs_qm_quotacheck_dqadjust(
	xfs_dquot_t		*dqp,
	xfs_qcnt_t		nblks,
	xfs_qcnt_t		rtblks)
{
	ASSERT(XFS_DQ_IS_LOCKED(dqp));
	xfs_dqtrace_entry(dqp, "QCHECK DQADJUST");
	/*
	 * Adjust the inode count and the block count to reflect this inode's
	 * resource usage.
	 */
	INT_MOD(dqp->q_core.d_icount, ARCH_CONVERT, +1);
	dqp->q_res_icount++;
	if (nblks) {
		INT_MOD(dqp->q_core.d_bcount, ARCH_CONVERT, nblks);
		dqp->q_res_bcount += nblks;
	}
	if (rtblks) {
		INT_MOD(dqp->q_core.d_rtbcount, ARCH_CONVERT, rtblks);
		dqp->q_res_rtbcount += rtblks;
	}

	/*
	 * Set default limits, adjust timers (since we changed usages)
	 */
	if (! XFS_IS_SUSER_DQUOT(dqp)) {
		xfs_qm_adjust_dqlimits(dqp->q_mount, &dqp->q_core);
		xfs_qm_adjust_dqtimers(dqp->q_mount, &dqp->q_core);
	}

	dqp->dq_flags |= XFS_DQ_DIRTY;
}

STATIC int
xfs_qm_get_rtblks(
	xfs_inode_t	*ip,
	xfs_qcnt_t	*O_rtblks)
{
	xfs_filblks_t	rtblks;			/* total rt blks */
	xfs_ifork_t	*ifp;			/* inode fork pointer */
	xfs_extnum_t	nextents;		/* number of extent entries */
	xfs_bmbt_rec_t	*base;			/* base of extent array */
	xfs_bmbt_rec_t	*ep;			/* pointer to an extent entry */
	int		error;

	ASSERT(XFS_IS_REALTIME_INODE(ip));
	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
		if ((error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK)))
			return (error);
	}
	rtblks = 0;
	nextents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
	base = &ifp->if_u1.if_extents[0];
	for (ep = base; ep < &base[nextents]; ep++)
		rtblks += xfs_bmbt_get_blockcount(ep);
	*O_rtblks = (xfs_qcnt_t)rtblks;
	return (0);
}

/*
 * callback routine supplied to bulkstat(). Given an inumber, find its
 * dquots and update them to account for resources taken by that inode.
 */
/* ARGSUSED */
STATIC int
xfs_qm_dqusage_adjust(
	xfs_mount_t	*mp,		/* mount point for filesystem */
	xfs_ino_t	ino,		/* inode number to get data for */
	void		__user *buffer,	/* not used */
	int		ubsize,		/* not used */
	void		*private_data,	/* not used */
	xfs_daddr_t	bno,		/* starting block of inode cluster */
	int		*ubused,	/* not used */
	void		*dip,		/* on-disk inode pointer (not used) */
	int		*res)		/* result code value */
{
	xfs_inode_t	*ip;
	xfs_dquot_t	*udqp, *gdqp;
	xfs_qcnt_t	nblks, rtblks;
	int		error;

	ASSERT(XFS_IS_QUOTA_RUNNING(mp));

	/*
	 * rootino must have its resources accounted for, not so with the quota
	 * inodes.
	 */
	if (ino == mp->m_sb.sb_uquotino || ino == mp->m_sb.sb_gquotino) {
		*res = BULKSTAT_RV_NOTHING;
		return XFS_ERROR(EINVAL);
	}

	/*
	 * We don't _need_ to take the ilock EXCL. However, the xfs_qm_dqget
	 * interface expects the inode to be exclusively locked because that's
	 * the case in all other instances. It's OK that we do this because
	 * quotacheck is done only at mount time.
	 */
	if ((error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_EXCL, &ip, bno))) {
		*res = BULKSTAT_RV_NOTHING;
		return (error);
	}

	if (ip->i_d.di_mode == 0) {
		xfs_iput_new(ip, XFS_ILOCK_EXCL);
		*res = BULKSTAT_RV_NOTHING;
		return XFS_ERROR(ENOENT);
	}

	/*
	 * Obtain the locked dquots. In case of an error (eg. allocation
	 * fails for ENOSPC), we return the negative of the error number
	 * to bulkstat, so that it can get propagated to quotacheck() and
	 * making us disable quotas for the file system.
	 */
	if ((error = xfs_qm_dqget_noattach(ip, &udqp, &gdqp))) {
		xfs_iput(ip, XFS_ILOCK_EXCL);
		*res = BULKSTAT_RV_GIVEUP;
		return (error);
	}

	rtblks = 0;
	if (! XFS_IS_REALTIME_INODE(ip)) {
		nblks = (xfs_qcnt_t)ip->i_d.di_nblocks;
	} else {
		/*
		 * Walk thru the extent list and count the realtime blocks.
		 */
		if ((error = xfs_qm_get_rtblks(ip, &rtblks))) {
			xfs_iput(ip, XFS_ILOCK_EXCL);
			if (udqp)
				xfs_qm_dqput(udqp);
			if (gdqp)
				xfs_qm_dqput(gdqp);
			*res = BULKSTAT_RV_GIVEUP;
			return (error);
		}
		nblks = (xfs_qcnt_t)ip->i_d.di_nblocks - rtblks;
	}
	ASSERT(ip->i_delayed_blks == 0);

	/*
	 * We can't release the inode while holding its dquot locks.
	 * The inode can go into inactive and might try to acquire the dquotlocks.
	 * So, just unlock here and do a vn_rele at the end.
	 */
	xfs_iunlock(ip, XFS_ILOCK_EXCL);

	/*
	 * Add the (disk blocks and inode) resources occupied by this
	 * inode to its dquots. We do this adjustment in the incore dquot,
	 * and also copy the changes to its buffer.
	 * We don't care about putting these changes in a transaction
	 * envelope because if we crash in the middle of a 'quotacheck'
	 * we have to start from the beginning anyway.
	 * Once we're done, we'll log all the dquot bufs.
	 *
	 * The *QUOTA_ON checks below may look pretty racey, but quotachecks
	 * and quotaoffs don't race. (Quotachecks happen at mount time only).
	 */
	if (XFS_IS_UQUOTA_ON(mp)) {
		ASSERT(udqp);
		xfs_qm_quotacheck_dqadjust(udqp, nblks, rtblks);
		xfs_qm_dqput(udqp);
	}
	if (XFS_IS_OQUOTA_ON(mp)) {
		ASSERT(gdqp);
		xfs_qm_quotacheck_dqadjust(gdqp, nblks, rtblks);
		xfs_qm_dqput(gdqp);
	}
	/*
	 * Now release the inode. This will send it to 'inactive', and
	 * possibly even free blocks.
	 */
	VN_RELE(XFS_ITOV(ip));

	/*
	 * Goto next inode.
	 */
	*res = BULKSTAT_RV_DIDONE;
	return (0);
}

/*
 * Walk thru all the filesystem inodes and construct a consistent view
 * of the disk quota world. If the quotacheck fails, disable quotas.
 */
int
xfs_qm_quotacheck(
	xfs_mount_t	*mp)
{
	int		done, count, error;
	xfs_ino_t	lastino;
	size_t		structsz;
	xfs_inode_t	*uip, *gip;
	uint		flags;

	count = INT_MAX;
	structsz = 1;
	lastino = 0;
	flags = 0;

	ASSERT(XFS_QI_UQIP(mp) || XFS_QI_GQIP(mp));
	ASSERT(XFS_IS_QUOTA_RUNNING(mp));

	/*
	 * There should be no cached dquots. The (simplistic) quotacheck
	 * algorithm doesn't like that.
	 */
	ASSERT(XFS_QI_MPLNDQUOTS(mp) == 0);

	cmn_err(CE_NOTE, "XFS quotacheck %s: Please wait.", mp->m_fsname);

	/*
	 * First we go thru all the dquots on disk, USR and GRP/PRJ, and reset
	 * their counters to zero. We need a clean slate.
	 * We don't log our changes till later.
	 */
	if ((uip = XFS_QI_UQIP(mp))) {
		if ((error = xfs_qm_dqiterate(mp, uip, XFS_QMOPT_UQUOTA)))
			goto error_return;
		flags |= XFS_UQUOTA_CHKD;
	}

	if ((gip = XFS_QI_GQIP(mp))) {
		if ((error = xfs_qm_dqiterate(mp, gip, XFS_IS_GQUOTA_ON(mp) ?
					XFS_QMOPT_GQUOTA : XFS_QMOPT_PQUOTA)))
			goto error_return;
		flags |= XFS_OQUOTA_CHKD;
	}

	do {
		/*
		 * Iterate thru all the inodes in the file system,
		 * adjusting the corresponding dquot counters in core.
		 */
		if ((error = xfs_bulkstat(mp, &lastino, &count,
				     xfs_qm_dqusage_adjust, NULL,
				     structsz, NULL,
				     BULKSTAT_FG_IGET|BULKSTAT_FG_VFSLOCKED,
				     &done)))
			break;

	} while (! done);

	/*
	 * We can get this error if we couldn't do a dquot allocation inside
	 * xfs_qm_dqusage_adjust (via bulkstat). We don't care about the
	 * dirty dquots that might be cached, we just want to get rid of them
	 * and turn quotaoff. The dquots won't be attached to any of the inodes
	 * at this point (because we intentionally didn't in dqget_noattach).
	 */
	if (error) {
		xfs_qm_dqpurge_all(mp,
				   XFS_QMOPT_UQUOTA|XFS_QMOPT_GQUOTA|
				   XFS_QMOPT_PQUOTA|XFS_QMOPT_QUOTAOFF);
		goto error_return;
	}
	/*
	 * We've made all the changes that we need to make incore.
	 * Now flush_them down to disk buffers.
	 */
	xfs_qm_dqflush_all(mp, XFS_QMOPT_DELWRI);

	/*
	 * We didn't log anything, because if we crashed, we'll have to
	 * start the quotacheck from scratch anyway. However, we must make
	 * sure that our dquot changes are secure before we put the
	 * quotacheck'd stamp on the superblock. So, here we do a synchronous
	 * flush.
	 */
	XFS_bflush(mp->m_ddev_targp);

	/*
	 * If one type of quotas is off, then it will lose its
	 * quotachecked status, since we won't be doing accounting for
	 * that type anymore.
	 */
	mp->m_qflags &= ~(XFS_OQUOTA_CHKD | XFS_UQUOTA_CHKD);
	mp->m_qflags |= flags;

	XQM_LIST_PRINT(&(XFS_QI_MPL_LIST(mp)), MPL_NEXT, "++++ Mp list +++");

 error_return:
	if (error) {
		cmn_err(CE_WARN, "XFS quotacheck %s: Unsuccessful (Error %d): "
			"Disabling quotas.",
			mp->m_fsname, error);
		/*
		 * We must turn off quotas.
		 */
		ASSERT(mp->m_quotainfo != NULL);
		ASSERT(xfs_Gqm != NULL);
		xfs_qm_destroy_quotainfo(mp);
		(void)xfs_mount_reset_sbqflags(mp);
	} else {
		cmn_err(CE_NOTE, "XFS quotacheck %s: Done.", mp->m_fsname);
	}
	return (error);
}

/*
 * This is called after the superblock has been read in and we're ready to
 * iget the quota inodes.
 */
STATIC int
xfs_qm_init_quotainos(
	xfs_mount_t	*mp)
{
	xfs_inode_t	*uip, *gip;
	int		error;
	__int64_t	sbflags;
	uint		flags;

	ASSERT(mp->m_quotainfo);
	uip = gip = NULL;
	sbflags = 0;
	flags = 0;

	/*
	 * Get the uquota and gquota inodes
	 */
	if (XFS_SB_VERSION_HASQUOTA(&mp->m_sb)) {
		if (XFS_IS_UQUOTA_ON(mp) &&
		    mp->m_sb.sb_uquotino != NULLFSINO) {
			ASSERT(mp->m_sb.sb_uquotino > 0);
			if ((error = xfs_iget(mp, NULL, mp->m_sb.sb_uquotino,
					     0, 0, &uip, 0)))
				return XFS_ERROR(error);
		}
		if (XFS_IS_OQUOTA_ON(mp) &&
		    mp->m_sb.sb_gquotino != NULLFSINO) {
			ASSERT(mp->m_sb.sb_gquotino > 0);
			if ((error = xfs_iget(mp, NULL, mp->m_sb.sb_gquotino,
					     0, 0, &gip, 0))) {
				if (uip)
					VN_RELE(XFS_ITOV(uip));
				return XFS_ERROR(error);
			}
		}
	} else {
		flags |= XFS_QMOPT_SBVERSION;
		sbflags |= (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
			    XFS_SB_GQUOTINO | XFS_SB_QFLAGS);
	}

	/*
	 * Create the two inodes, if they don't exist already. The changes
	 * made above will get added to a transaction and logged in one of
	 * the qino_alloc calls below.  If the device is readonly,
	 * temporarily switch to read-write to do this.
	 */
	if (XFS_IS_UQUOTA_ON(mp) && uip == NULL) {
		if ((error = xfs_qm_qino_alloc(mp, &uip,
					      sbflags | XFS_SB_UQUOTINO,
					      flags | XFS_QMOPT_UQUOTA)))
			return XFS_ERROR(error);

		flags &= ~XFS_QMOPT_SBVERSION;
	}
	if (XFS_IS_OQUOTA_ON(mp) && gip == NULL) {
		flags |= (XFS_IS_GQUOTA_ON(mp) ?
				XFS_QMOPT_GQUOTA : XFS_QMOPT_PQUOTA);
		error = xfs_qm_qino_alloc(mp, &gip,
					  sbflags | XFS_SB_GQUOTINO, flags);
		if (error) {
			if (uip)
				VN_RELE(XFS_ITOV(uip));

			return XFS_ERROR(error);
		}
	}

	XFS_QI_UQIP(mp) = uip;
	XFS_QI_GQIP(mp) = gip;

	return (0);
}


/*
 * Traverse the freelist of dquots and attempt to reclaim a maximum of
 * 'howmany' dquots. This operation races with dqlookup(), and attempts to
 * favor the lookup function ...
 * XXXsup merge this with qm_reclaim_one().
 */
STATIC int
xfs_qm_shake_freelist(
	int howmany)
{
	int		nreclaimed;
	xfs_dqhash_t	*hash;
	xfs_dquot_t	*dqp, *nextdqp;
	int		restarts;
	int		nflushes;

	if (howmany <= 0)
		return (0);

	nreclaimed = 0;
	restarts = 0;
	nflushes = 0;

#ifdef QUOTADEBUG
	cmn_err(CE_DEBUG, "Shake free 0x%x", howmany);
#endif
	/* lock order is : hashchainlock, freelistlock, mplistlock */
 tryagain:
	xfs_qm_freelist_lock(xfs_Gqm);

	for (dqp = xfs_Gqm->qm_dqfreelist.qh_next;
	     ((dqp != (xfs_dquot_t *) &xfs_Gqm->qm_dqfreelist) &&
	      nreclaimed < howmany); ) {
		xfs_dqlock(dqp);

		/*
		 * We are racing with dqlookup here. Naturally we don't
		 * want to reclaim a dquot that lookup wants.
		 */
		if (dqp->dq_flags & XFS_DQ_WANT) {
			xfs_dqunlock(dqp);
			xfs_qm_freelist_unlock(xfs_Gqm);
			if (++restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
				return (nreclaimed);
			XQM_STATS_INC(xqmstats.xs_qm_dqwants);
			goto tryagain;
		}

		/*
		 * If the dquot is inactive, we are assured that it is
		 * not on the mplist or the hashlist, and that makes our
		 * life easier.
		 */
		if (dqp->dq_flags & XFS_DQ_INACTIVE) {
			ASSERT(dqp->q_mount == NULL);
			ASSERT(! XFS_DQ_IS_DIRTY(dqp));
			ASSERT(dqp->HL_PREVP == NULL);
			ASSERT(dqp->MPL_PREVP == NULL);
			XQM_STATS_INC(xqmstats.xs_qm_dqinact_reclaims);
			nextdqp = dqp->dq_flnext;
			goto off_freelist;
		}

		ASSERT(dqp->MPL_PREVP);
		/*
		 * Try to grab the flush lock. If this dquot is in the process of
		 * getting flushed to disk, we don't want to reclaim it.
		 */
		if (! xfs_qm_dqflock_nowait(dqp)) {
			xfs_dqunlock(dqp);
			dqp = dqp->dq_flnext;
			continue;
		}

		/*
		 * We have the flush lock so we know that this is not in the
		 * process of being flushed. So, if this is dirty, flush it
		 * DELWRI so that we don't get a freelist infested with
		 * dirty dquots.
		 */
		if (XFS_DQ_IS_DIRTY(dqp)) {
			xfs_dqtrace_entry(dqp, "DQSHAKE: DQDIRTY");
			/*
			 * We flush it delayed write, so don't bother
			 * releasing the mplock.
			 */
			(void) xfs_qm_dqflush(dqp, XFS_QMOPT_DELWRI);
			xfs_dqunlock(dqp); /* dqflush unlocks dqflock */
			dqp = dqp->dq_flnext;
			continue;
		}
		/*
		 * We're trying to get the hashlock out of order. This races
		 * with dqlookup; so, we giveup and goto the next dquot if
		 * we couldn't get the hashlock. This way, we won't starve
		 * a dqlookup process that holds the hashlock that is
		 * waiting for the freelist lock.
		 */
		if (! xfs_qm_dqhashlock_nowait(dqp)) {
			xfs_dqfunlock(dqp);
			xfs_dqunlock(dqp);
			dqp = dqp->dq_flnext;
			continue;
		}
		/*
		 * This races with dquot allocation code as well as dqflush_all
		 * and reclaim code. So, if we failed to grab the mplist lock,
		 * giveup everything and start over.
		 */
		hash = dqp->q_hash;
		ASSERT(hash);
		if (! xfs_qm_mplist_nowait(dqp->q_mount)) {
			/* XXX put a sentinel so that we can come back here */
			xfs_dqfunlock(dqp);
			xfs_dqunlock(dqp);
			XFS_DQ_HASH_UNLOCK(hash);
			xfs_qm_freelist_unlock(xfs_Gqm);
			if (++restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
				return (nreclaimed);
			goto tryagain;
		}
		xfs_dqtrace_entry(dqp, "DQSHAKE: UNLINKING");
#ifdef QUOTADEBUG
		cmn_err(CE_DEBUG, "Shake 0x%p, ID 0x%x\n",
			dqp, INT_GET(dqp->q_core.d_id, ARCH_CONVERT));
#endif
		ASSERT(dqp->q_nrefs == 0);
		nextdqp = dqp->dq_flnext;
		XQM_MPLIST_REMOVE(&(XFS_QI_MPL_LIST(dqp->q_mount)), dqp);
		XQM_HASHLIST_REMOVE(hash, dqp);
		xfs_dqfunlock(dqp);
		xfs_qm_mplist_unlock(dqp->q_mount);
		XFS_DQ_HASH_UNLOCK(hash);

 off_freelist:
		XQM_FREELIST_REMOVE(dqp);
		xfs_dqunlock(dqp);
		nreclaimed++;
		XQM_STATS_INC(xqmstats.xs_qm_dqshake_reclaims);
		xfs_qm_dqdestroy(dqp);
		dqp = nextdqp;
	}
	xfs_qm_freelist_unlock(xfs_Gqm);
	return (nreclaimed);
}


/*
 * The kmem_shake interface is invoked when memory is running low.
 */
/* ARGSUSED */
STATIC int
xfs_qm_shake(int nr_to_scan, unsigned int gfp_mask)
{
	int	ndqused, nfree, n;

	if (!kmem_shake_allow(gfp_mask))
		return (0);
	if (!xfs_Gqm)
		return (0);

	nfree = xfs_Gqm->qm_dqfreelist.qh_nelems; /* free dquots */
	/* incore dquots in all f/s's */
	ndqused = atomic_read(&xfs_Gqm->qm_totaldquots) - nfree;

	ASSERT(ndqused >= 0);

	if (nfree <= ndqused && nfree < ndquot)
		return (0);

	ndqused *= xfs_Gqm->qm_dqfree_ratio;	/* target # of free dquots */
	n = nfree - ndqused - ndquot;		/* # over target */

	return xfs_qm_shake_freelist(MAX(nfree, n));
}


/*
 * Just pop the least recently used dquot off the freelist and
 * recycle it. The returned dquot is locked.
 */
STATIC xfs_dquot_t *
xfs_qm_dqreclaim_one(void)
{
	xfs_dquot_t	*dqpout;
	xfs_dquot_t	*dqp;
	int		restarts;
	int		nflushes;

	restarts = 0;
	dqpout = NULL;
	nflushes = 0;

	/* lockorder: hashchainlock, freelistlock, mplistlock, dqlock, dqflock */
 startagain:
	xfs_qm_freelist_lock(xfs_Gqm);

	FOREACH_DQUOT_IN_FREELIST(dqp, &(xfs_Gqm->qm_dqfreelist)) {
		xfs_dqlock(dqp);

		/*
		 * We are racing with dqlookup here. Naturally we don't
		 * want to reclaim a dquot that lookup wants. We release the
		 * freelist lock and start over, so that lookup will grab
		 * both the dquot and the freelistlock.
		 */
		if (dqp->dq_flags & XFS_DQ_WANT) {
			ASSERT(! (dqp->dq_flags & XFS_DQ_INACTIVE));
			xfs_dqtrace_entry(dqp, "DQRECLAIM: DQWANT");
			xfs_dqunlock(dqp);
			xfs_qm_freelist_unlock(xfs_Gqm);
			if (++restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
				return (NULL);
			XQM_STATS_INC(xqmstats.xs_qm_dqwants);
			goto startagain;
		}

		/*
		 * If the dquot is inactive, we are assured that it is
		 * not on the mplist or the hashlist, and that makes our
		 * life easier.
		 */
		if (dqp->dq_flags & XFS_DQ_INACTIVE) {
			ASSERT(dqp->q_mount == NULL);
			ASSERT(! XFS_DQ_IS_DIRTY(dqp));
			ASSERT(dqp->HL_PREVP == NULL);
			ASSERT(dqp->MPL_PREVP == NULL);
			XQM_FREELIST_REMOVE(dqp);
			xfs_dqunlock(dqp);
			dqpout = dqp;
			XQM_STATS_INC(xqmstats.xs_qm_dqinact_reclaims);
			break;
		}

		ASSERT(dqp->q_hash);
		ASSERT(dqp->MPL_PREVP);

		/*
		 * Try to grab the flush lock. If this dquot is in the process of
		 * getting flushed to disk, we don't want to reclaim it.
		 */
		if (! xfs_qm_dqflock_nowait(dqp)) {
			xfs_dqunlock(dqp);
			continue;
		}

		/*
		 * We have the flush lock so we know that this is not in the
		 * process of being flushed. So, if this is dirty, flush it
		 * DELWRI so that we don't get a freelist infested with
		 * dirty dquots.
		 */
		if (XFS_DQ_IS_DIRTY(dqp)) {
			xfs_dqtrace_entry(dqp, "DQRECLAIM: DQDIRTY");
			/*
			 * We flush it delayed write, so don't bother
			 * releasing the freelist lock.
			 */
			(void) xfs_qm_dqflush(dqp, XFS_QMOPT_DELWRI);
			xfs_dqunlock(dqp); /* dqflush unlocks dqflock */
			continue;
		}

		if (! xfs_qm_mplist_nowait(dqp->q_mount)) {
			xfs_dqfunlock(dqp);
			xfs_dqunlock(dqp);
			continue;
		}

		if (! xfs_qm_dqhashlock_nowait(dqp))
			goto mplistunlock;

		ASSERT(dqp->q_nrefs == 0);
		xfs_dqtrace_entry(dqp, "DQRECLAIM: UNLINKING");
		XQM_MPLIST_REMOVE(&(XFS_QI_MPL_LIST(dqp->q_mount)), dqp);
		XQM_HASHLIST_REMOVE(dqp->q_hash, dqp);
		XQM_FREELIST_REMOVE(dqp);
		dqpout = dqp;
		XFS_DQ_HASH_UNLOCK(dqp->q_hash);
 mplistunlock:
		xfs_qm_mplist_unlock(dqp->q_mount);
		xfs_dqfunlock(dqp);
		xfs_dqunlock(dqp);
		if (dqpout)
			break;
	}

	xfs_qm_freelist_unlock(xfs_Gqm);
	return (dqpout);
}


/*------------------------------------------------------------------*/

/*
 * Return a new incore dquot. Depending on the number of
 * dquots in the system, we either allocate a new one on the kernel heap,
 * or reclaim a free one.
 * Return value is B_TRUE if we allocated a new dquot, B_FALSE if we managed
 * to reclaim an existing one from the freelist.
 */
boolean_t
xfs_qm_dqalloc_incore(
	xfs_dquot_t **O_dqpp)
{
	xfs_dquot_t	*dqp;

	/*
	 * Check against high water mark to see if we want to pop
	 * a nincompoop dquot off the freelist.
	 */
	if (atomic_read(&xfs_Gqm->qm_totaldquots) >= ndquot) {
		/*
		 * Try to recycle a dquot from the freelist.
		 */
		if ((dqp = xfs_qm_dqreclaim_one())) {
			XQM_STATS_INC(xqmstats.xs_qm_dqreclaims);
			/*
			 * Just zero the core here. The rest will get
			 * reinitialized by caller. XXX we shouldn't even
			 * do this zero ...
			 */
			memset(&dqp->q_core, 0, sizeof(dqp->q_core));
			*O_dqpp = dqp;
			return (B_FALSE);
		}
		XQM_STATS_INC(xqmstats.xs_qm_dqreclaim_misses);
	}

	/*
	 * Allocate a brand new dquot on the kernel heap and return it
	 * to the caller to initialize.
	 */
	ASSERT(xfs_Gqm->qm_dqzone != NULL);
	*O_dqpp = kmem_zone_zalloc(xfs_Gqm->qm_dqzone, KM_SLEEP);
	atomic_inc(&xfs_Gqm->qm_totaldquots);

	return (B_TRUE);
}


/*
 * Start a transaction and write the incore superblock changes to
 * disk. flags parameter indicates which fields have changed.
 */
int
xfs_qm_write_sb_changes(
	xfs_mount_t	*mp,
	__int64_t	flags)
{
	xfs_trans_t	*tp;
	int		error;

#ifdef QUOTADEBUG
	cmn_err(CE_NOTE, "Writing superblock quota changes :%s", mp->m_fsname);
#endif
	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
	if ((error = xfs_trans_reserve(tp, 0,
				      mp->m_sb.sb_sectsize + 128, 0,
				      0,
				      XFS_DEFAULT_LOG_COUNT))) {
		xfs_trans_cancel(tp, 0);
		return (error);
	}

	xfs_mod_sb(tp, flags);
	(void) xfs_trans_commit(tp, 0, NULL);

	return (0);
}


/* --------------- utility functions for vnodeops ---------------- */


/*
 * Given an inode, a uid and gid (from cred_t) make sure that we have
 * allocated relevant dquot(s) on disk, and that we won't exceed inode
 * quotas by creating this file.
 * This also attaches dquot(s) to the given inode after locking it,
 * and returns the dquots corresponding to the uid and/or gid.
 *
 * in	: inode (unlocked)
 * out	: udquot, gdquot with references taken and unlocked
 */
int
xfs_qm_vop_dqalloc(
	xfs_mount_t	*mp,
	xfs_inode_t	*ip,
	uid_t		uid,
	gid_t		gid,
	prid_t		prid,
	uint		flags,
	xfs_dquot_t	**O_udqpp,
	xfs_dquot_t	**O_gdqpp)
{
	int		error;
	xfs_dquot_t	*uq, *gq;
	uint		lockflags;

	if (!XFS_IS_QUOTA_ON(mp))
		return 0;

	lockflags = XFS_ILOCK_EXCL;
	xfs_ilock(ip, lockflags);

	if ((flags & XFS_QMOPT_INHERIT) &&
	    XFS_INHERIT_GID(ip, XFS_MTOVFS(mp)))
		gid = ip->i_d.di_gid;

	/*
	 * Attach the dquot(s) to this inode, doing a dquot allocation
	 * if necessary. The dquot(s) will not be locked.
	 */
	if (XFS_NOT_DQATTACHED(mp, ip)) {
		if ((error = xfs_qm_dqattach(ip, XFS_QMOPT_DQALLOC |
					    XFS_QMOPT_ILOCKED))) {
			xfs_iunlock(ip, lockflags);
			return (error);
		}
	}

	uq = gq = NULL;
	if ((flags & XFS_QMOPT_UQUOTA) && XFS_IS_UQUOTA_ON(mp)) {
		if (ip->i_d.di_uid != uid) {
			/*
			 * What we need is the dquot that has this uid, and
			 * if we send the inode to dqget, the uid of the inode
			 * takes priority over what's sent in the uid argument.
			 * We must unlock inode here before calling dqget if
			 * we're not sending the inode, because otherwise
			 * we'll deadlock by doing trans_reserve while
			 * holding ilock.
			 */
			xfs_iunlock(ip, lockflags);
			if ((error = xfs_qm_dqget(mp, NULL, (xfs_dqid_t) uid,
						 XFS_DQ_USER,
						 XFS_QMOPT_DQALLOC |
						 XFS_QMOPT_DOWARN,
						 &uq))) {
				ASSERT(error != ENOENT);
				return (error);
			}
			/*
			 * Get the ilock in the right order.
			 */
			xfs_dqunlock(uq);
			lockflags = XFS_ILOCK_SHARED;
			xfs_ilock(ip, lockflags);
		} else {
			/*
			 * Take an extra reference, because we'll return
			 * this to caller
			 */
			ASSERT(ip->i_udquot);
			uq = ip->i_udquot;
			xfs_dqlock(uq);
			XFS_DQHOLD(uq);
			xfs_dqunlock(uq);
		}
	}
	if ((flags & XFS_QMOPT_GQUOTA) && XFS_IS_GQUOTA_ON(mp)) {
		if (ip->i_d.di_gid != gid) {
			xfs_iunlock(ip, lockflags);
			if ((error = xfs_qm_dqget(mp, NULL, (xfs_dqid_t)gid,
						 XFS_DQ_GROUP,
						 XFS_QMOPT_DQALLOC |
						 XFS_QMOPT_DOWARN,
						 &gq))) {
				if (uq)
					xfs_qm_dqrele(uq);
				ASSERT(error != ENOENT);
				return (error);
			}
			xfs_dqunlock(gq);
			lockflags = XFS_ILOCK_SHARED;
			xfs_ilock(ip, lockflags);
		} else {
			ASSERT(ip->i_gdquot);
			gq = ip->i_gdquot;
			xfs_dqlock(gq);
			XFS_DQHOLD(gq);
			xfs_dqunlock(gq);
		}
	} else if ((flags & XFS_QMOPT_PQUOTA) && XFS_IS_PQUOTA_ON(mp)) {
		if (ip->i_d.di_projid != prid) {
			xfs_iunlock(ip, lockflags);
			if ((error = xfs_qm_dqget(mp, NULL, (xfs_dqid_t)prid,
						 XFS_DQ_PROJ,
						 XFS_QMOPT_DQALLOC |
						 XFS_QMOPT_DOWARN,
						 &gq))) {
				if (uq)
					xfs_qm_dqrele(uq);
				ASSERT(error != ENOENT);
				return (error);
			}
			xfs_dqunlock(gq);
			lockflags = XFS_ILOCK_SHARED;
			xfs_ilock(ip, lockflags);
		} else {
			ASSERT(ip->i_gdquot);
			gq = ip->i_gdquot;
			xfs_dqlock(gq);
			XFS_DQHOLD(gq);
			xfs_dqunlock(gq);
		}
	}
	if (uq)
		xfs_dqtrace_entry_ino(uq, "DQALLOC", ip);

	xfs_iunlock(ip, lockflags);
	if (O_udqpp)
		*O_udqpp = uq;
	else if (uq)
		xfs_qm_dqrele(uq);
	if (O_gdqpp)
		*O_gdqpp = gq;
	else if (gq)
		xfs_qm_dqrele(gq);
	return (0);
}

/*
 * Actually transfer ownership, and do dquot modifications.
 * These were already reserved.
 */
xfs_dquot_t *
xfs_qm_vop_chown(
	xfs_trans_t	*tp,
	xfs_inode_t	*ip,
	xfs_dquot_t	**IO_olddq,
	xfs_dquot_t	*newdq)
{
	xfs_dquot_t	*prevdq;
	uint		bfield = XFS_IS_REALTIME_INODE(ip) ?
				 XFS_TRANS_DQ_RTBCOUNT : XFS_TRANS_DQ_BCOUNT;

	ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
	ASSERT(XFS_IS_QUOTA_RUNNING(ip->i_mount));

	/* old dquot */
	prevdq = *IO_olddq;
	ASSERT(prevdq);
	ASSERT(prevdq != newdq);

	xfs_trans_mod_dquot(tp, prevdq, bfield, -(ip->i_d.di_nblocks));
	xfs_trans_mod_dquot(tp, prevdq, XFS_TRANS_DQ_ICOUNT, -1);

	/* the sparkling new dquot */
	xfs_trans_mod_dquot(tp, newdq, bfield, ip->i_d.di_nblocks);
	xfs_trans_mod_dquot(tp, newdq, XFS_TRANS_DQ_ICOUNT, 1);

	/*
	 * Take an extra reference, because the inode
	 * is going to keep this dquot pointer even
	 * after the trans_commit.
	 */
	xfs_dqlock(newdq);
	XFS_DQHOLD(newdq);
	xfs_dqunlock(newdq);
	*IO_olddq = newdq;

	return (prevdq);
}

/*
 * Quota reservations for setattr(AT_UID|AT_GID|AT_PROJID).
 */
int
xfs_qm_vop_chown_reserve(
	xfs_trans_t	*tp,
	xfs_inode_t	*ip,
	xfs_dquot_t	*udqp,
	xfs_dquot_t	*gdqp,
	uint		flags)
{
	int		error;
	xfs_mount_t	*mp;
	uint		delblks, blkflags;
	xfs_dquot_t	*unresudq, *unresgdq, *delblksudq, *delblksgdq;

	ASSERT(XFS_ISLOCKED_INODE(ip));
	mp = ip->i_mount;
	ASSERT(XFS_IS_QUOTA_RUNNING(mp));

	delblks = ip->i_delayed_blks;
	delblksudq = delblksgdq = unresudq = unresgdq = NULL;
	blkflags = XFS_IS_REALTIME_INODE(ip) ?
			XFS_QMOPT_RES_RTBLKS : XFS_QMOPT_RES_REGBLKS;

	if (XFS_IS_UQUOTA_ON(mp) && udqp &&
	    ip->i_d.di_uid != (uid_t)INT_GET(udqp->q_core.d_id, ARCH_CONVERT)) {
		delblksudq = udqp;
		/*
		 * If there are delayed allocation blocks, then we have to
		 * unreserve those from the old dquot, and add them to the
		 * new dquot.
		 */
		if (delblks) {
			ASSERT(ip->i_udquot);
			unresudq = ip->i_udquot;
		}
	}
	if (XFS_IS_OQUOTA_ON(ip->i_mount) && gdqp) {
		if ((XFS_IS_GQUOTA_ON(ip->i_mount) && ip->i_d.di_gid !=
				INT_GET(gdqp->q_core.d_id, ARCH_CONVERT)) ||
		    (XFS_IS_PQUOTA_ON(ip->i_mount) && ip->i_d.di_projid !=
				INT_GET(gdqp->q_core.d_id, ARCH_CONVERT))) {
			delblksgdq = gdqp;
			if (delblks) {
				ASSERT(ip->i_gdquot);
				unresgdq = ip->i_gdquot;
			}
		}
	}

	if ((error = xfs_trans_reserve_quota_bydquots(tp, ip->i_mount,
				delblksudq, delblksgdq, ip->i_d.di_nblocks, 1,
				flags | blkflags)))
		return (error);

	/*
	 * Do the delayed blks reservations/unreservations now. Since, these
	 * are done without the help of a transaction, if a reservation fails
	 * its previous reservations won't be automatically undone by trans
	 * code. So, we have to do it manually here.
	 */
	if (delblks) {
		/*
		 * Do the reservations first. Unreservation can't fail.
		 */
		ASSERT(delblksudq || delblksgdq);
		ASSERT(unresudq || unresgdq);
		if ((error = xfs_trans_reserve_quota_bydquots(NULL, ip->i_mount,
				delblksudq, delblksgdq, (xfs_qcnt_t)delblks, 0,
				flags | blkflags)))
			return (error);
		xfs_trans_reserve_quota_bydquots(NULL, ip->i_mount,
				unresudq, unresgdq, -((xfs_qcnt_t)delblks), 0,
				blkflags);
	}

	return (0);
}

int
xfs_qm_vop_rename_dqattach(
	xfs_inode_t	**i_tab)
{
	xfs_inode_t	*ip;
	int		i;
	int		error;

	ip = i_tab[0];

	if (! XFS_IS_QUOTA_ON(ip->i_mount))
		return (0);

	if (XFS_NOT_DQATTACHED(ip->i_mount, ip)) {
		error = xfs_qm_dqattach(ip, 0);
		if (error)
			return (error);
	}
	for (i = 1; (i < 4 && i_tab[i]); i++) {
		/*
		 * Watch out for duplicate entries in the table.
		 */
		if ((ip = i_tab[i]) != i_tab[i-1]) {
			if (XFS_NOT_DQATTACHED(ip->i_mount, ip)) {
				error = xfs_qm_dqattach(ip, 0);
				if (error)
					return (error);
			}
		}
	}
	return (0);
}

void
xfs_qm_vop_dqattach_and_dqmod_newinode(
	xfs_trans_t	*tp,
	xfs_inode_t	*ip,
	xfs_dquot_t	*udqp,
	xfs_dquot_t	*gdqp)
{
	if (!XFS_IS_QUOTA_ON(tp->t_mountp))
		return;

	ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
	ASSERT(XFS_IS_QUOTA_RUNNING(tp->t_mountp));

	if (udqp) {
		xfs_dqlock(udqp);
		XFS_DQHOLD(udqp);
		xfs_dqunlock(udqp);
		ASSERT(ip->i_udquot == NULL);
		ip->i_udquot = udqp;
		ASSERT(ip->i_d.di_uid == INT_GET(udqp->q_core.d_id, ARCH_CONVERT));
		xfs_trans_mod_dquot(tp, udqp, XFS_TRANS_DQ_ICOUNT, 1);
	}
	if (gdqp) {
		xfs_dqlock(gdqp);
		XFS_DQHOLD(gdqp);
		xfs_dqunlock(gdqp);
		ASSERT(ip->i_gdquot == NULL);
		ip->i_gdquot = gdqp;
		ASSERT(ip->i_d.di_gid == INT_GET(gdqp->q_core.d_id, ARCH_CONVERT));
		xfs_trans_mod_dquot(tp, gdqp, XFS_TRANS_DQ_ICOUNT, 1);
	}
}

/* ------------- list stuff -----------------*/
STATIC void
xfs_qm_freelist_init(xfs_frlist_t *ql)
{
	ql->qh_next = ql->qh_prev = (xfs_dquot_t *) ql;
	mutex_init(&ql->qh_lock, MUTEX_DEFAULT, "dqf");
	ql->qh_version = 0;
	ql->qh_nelems = 0;
}

STATIC void
xfs_qm_freelist_destroy(xfs_frlist_t *ql)
{
	xfs_dquot_t	*dqp, *nextdqp;

	mutex_lock(&ql->qh_lock, PINOD);
	for (dqp = ql->qh_next;
	     dqp != (xfs_dquot_t *)ql; ) {
		xfs_dqlock(dqp);
		nextdqp = dqp->dq_flnext;
#ifdef QUOTADEBUG
		cmn_err(CE_DEBUG, "FREELIST destroy 0x%p", dqp);
#endif
		XQM_FREELIST_REMOVE(dqp);
		xfs_dqunlock(dqp);
		xfs_qm_dqdestroy(dqp);
		dqp = nextdqp;
	}
	/*
	 * Don't bother about unlocking.
	 */
	mutex_destroy(&ql->qh_lock);

	ASSERT(ql->qh_nelems == 0);
}

STATIC void
xfs_qm_freelist_insert(xfs_frlist_t *ql, xfs_dquot_t *dq)
{
	dq->dq_flnext = ql->qh_next;
	dq->dq_flprev = (xfs_dquot_t *)ql;
	ql->qh_next = dq;
	dq->dq_flnext->dq_flprev = dq;
	xfs_Gqm->qm_dqfreelist.qh_nelems++;
	xfs_Gqm->qm_dqfreelist.qh_version++;
}

void
xfs_qm_freelist_unlink(xfs_dquot_t *dq)
{
	xfs_dquot_t *next = dq->dq_flnext;
	xfs_dquot_t *prev = dq->dq_flprev;

	next->dq_flprev = prev;
	prev->dq_flnext = next;
	dq->dq_flnext = dq->dq_flprev = dq;
	xfs_Gqm->qm_dqfreelist.qh_nelems--;
	xfs_Gqm->qm_dqfreelist.qh_version++;
}

void
xfs_qm_freelist_append(xfs_frlist_t *ql, xfs_dquot_t *dq)
{
	xfs_qm_freelist_insert((xfs_frlist_t *)ql->qh_prev, dq);
}

STATIC int
xfs_qm_dqhashlock_nowait(
	xfs_dquot_t *dqp)
{
	int locked;

	locked = mutex_trylock(&((dqp)->q_hash->qh_lock));
	return (locked);
}

int
xfs_qm_freelist_lock_nowait(
	xfs_qm_t *xqm)
{
	int locked;

	locked = mutex_trylock(&(xqm->qm_dqfreelist.qh_lock));
	return (locked);
}

STATIC int
xfs_qm_mplist_nowait(
	xfs_mount_t	*mp)
{
	int locked;

	ASSERT(mp->m_quotainfo);
	locked = mutex_trylock(&(XFS_QI_MPLLOCK(mp)));
	return (locked);
}