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/*
* 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 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
*/
#ifndef __XFS_DQUOT_H__
#define __XFS_DQUOT_H__
/*
* Dquots are structures that hold quota information about a user or a group,
* much like inodes are for files. In fact, dquots share many characteristics
* with inodes. However, dquots can also be a centralized resource, relative
* to a collection of inodes. In this respect, dquots share some characteristics
* of the superblock.
* XFS dquots exploit both those in its algorithms. They make every attempt
* to not be a bottleneck when quotas are on and have minimal impact, if any,
* when quotas are off.
*/
/*
* The hash chain headers (hash buckets)
*/
typedef struct xfs_dqhash {
struct xfs_dquot *qh_next;
struct mutex qh_lock;
uint qh_version; /* ever increasing version */
uint qh_nelems; /* number of dquots on the list */
} xfs_dqhash_t;
typedef struct xfs_dqlink {
struct xfs_dquot *ql_next; /* forward link */
struct xfs_dquot **ql_prevp; /* pointer to prev ql_next */
} xfs_dqlink_t;
struct xfs_mount;
struct xfs_trans;
/*
* This is the marker which is designed to occupy the first few
* bytes of the xfs_dquot_t structure. Even inside this, the freelist pointers
* must come first.
* This serves as the marker ("sentinel") when we have to restart list
* iterations because of locking considerations.
*/
typedef struct xfs_dqmarker {
struct xfs_dquot*dqm_flnext; /* link to freelist: must be first */
struct xfs_dquot*dqm_flprev;
xfs_dqlink_t dqm_mplist; /* link to mount's list of dquots */
xfs_dqlink_t dqm_hashlist; /* link to the hash chain */
uint dqm_flags; /* various flags (XFS_DQ_*) */
} xfs_dqmarker_t;
/*
* The incore dquot structure
*/
typedef struct xfs_dquot {
xfs_dqmarker_t q_lists; /* list ptrs, q_flags (marker) */
xfs_dqhash_t *q_hash; /* the hashchain header */
struct xfs_mount*q_mount; /* filesystem this relates to */
struct xfs_trans*q_transp; /* trans this belongs to currently */
uint q_nrefs; /* # active refs from inodes */
xfs_daddr_t q_blkno; /* blkno of dquot buffer */
int q_bufoffset; /* off of dq in buffer (# dquots) */
xfs_fileoff_t q_fileoffset; /* offset in quotas file */
struct xfs_dquot*q_gdquot; /* group dquot, hint only */
xfs_disk_dquot_t q_core; /* actual usage & quotas */
xfs_dq_logitem_t q_logitem; /* dquot log item */
xfs_qcnt_t q_res_bcount; /* total regular nblks used+reserved */
xfs_qcnt_t q_res_icount; /* total inos allocd+reserved */
xfs_qcnt_t q_res_rtbcount;/* total realtime blks used+reserved */
struct mutex q_qlock; /* quota lock */
struct completion q_flush; /* flush completion queue */
atomic_t q_pincount; /* dquot pin count */
wait_queue_head_t q_pinwait; /* dquot pinning wait queue */
} xfs_dquot_t;
#define dq_flnext q_lists.dqm_flnext
#define dq_flprev q_lists.dqm_flprev
#define dq_mplist q_lists.dqm_mplist
#define dq_hashlist q_lists.dqm_hashlist
#define dq_flags q_lists.dqm_flags
/*
* Lock hierarchy for q_qlock:
* XFS_QLOCK_NORMAL is the implicit default,
* XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
*/
enum {
XFS_QLOCK_NORMAL = 0,
XFS_QLOCK_NESTED,
};
#define XFS_DQHOLD(dqp) ((dqp)->q_nrefs++)
/*
* Manage the q_flush completion queue embedded in the dquot. This completion
* queue synchronizes processes attempting to flush the in-core dquot back to
* disk.
*/
static inline void xfs_dqflock(xfs_dquot_t *dqp)
{
wait_for_completion(&dqp->q_flush);
}
static inline int xfs_dqflock_nowait(xfs_dquot_t *dqp)
{
return try_wait_for_completion(&dqp->q_flush);
}
static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
{
complete(&dqp->q_flush);
}
#define XFS_DQ_IS_LOCKED(dqp) (mutex_is_locked(&((dqp)->q_qlock)))
#define XFS_DQ_IS_ON_FREELIST(dqp) ((dqp)->dq_flnext != (dqp))
#define XFS_DQ_IS_DIRTY(dqp) ((dqp)->dq_flags & XFS_DQ_DIRTY)
#define XFS_QM_ISUDQ(dqp) ((dqp)->dq_flags & XFS_DQ_USER)
#define XFS_QM_ISPDQ(dqp) ((dqp)->dq_flags & XFS_DQ_PROJ)
#define XFS_QM_ISGDQ(dqp) ((dqp)->dq_flags & XFS_DQ_GROUP)
#define XFS_DQ_TO_QINF(dqp) ((dqp)->q_mount->m_quotainfo)
#define XFS_DQ_TO_QIP(dqp) (XFS_QM_ISUDQ(dqp) ? \
XFS_DQ_TO_QINF(dqp)->qi_uquotaip : \
XFS_DQ_TO_QINF(dqp)->qi_gquotaip)
#define XFS_IS_THIS_QUOTA_OFF(d) (! (XFS_QM_ISUDQ(d) ? \
(XFS_IS_UQUOTA_ON((d)->q_mount)) : \
(XFS_IS_OQUOTA_ON((d)->q_mount))))
#ifdef QUOTADEBUG
extern void xfs_qm_dqprint(xfs_dquot_t *);
#else
#define xfs_qm_dqprint(a)
#endif
extern void xfs_qm_dqdestroy(xfs_dquot_t *);
extern int xfs_qm_dqflush(xfs_dquot_t *, uint);
extern int xfs_qm_dqpurge(xfs_dquot_t *);
extern void xfs_qm_dqunpin_wait(xfs_dquot_t *);
extern int xfs_qm_dqlock_nowait(xfs_dquot_t *);
extern void xfs_qm_dqflock_pushbuf_wait(xfs_dquot_t *dqp);
extern void xfs_qm_adjust_dqtimers(xfs_mount_t *,
xfs_disk_dquot_t *);
extern void xfs_qm_adjust_dqlimits(xfs_mount_t *,
xfs_disk_dquot_t *);
extern int xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
xfs_dqid_t, uint, uint, xfs_dquot_t **);
extern void xfs_qm_dqput(xfs_dquot_t *);
extern void xfs_dqlock(xfs_dquot_t *);
extern void xfs_dqlock2(xfs_dquot_t *, xfs_dquot_t *);
extern void xfs_dqunlock(xfs_dquot_t *);
extern void xfs_dqunlock_nonotify(xfs_dquot_t *);
#endif /* __XFS_DQUOT_H__ */
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