https://github.com/torvalds/linux
Tip revision: d72e90f33aa4709ebecc5005562f52335e106a60 authored by Linus Torvalds on 22 July 2018, 21:12:20 UTC
Linux 4.18-rc6
Linux 4.18-rc6
Tip revision: d72e90f
xfs_dquot.h
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#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.
*/
struct xfs_mount;
struct xfs_trans;
enum {
XFS_QLOWSP_1_PCNT = 0,
XFS_QLOWSP_3_PCNT,
XFS_QLOWSP_5_PCNT,
XFS_QLOWSP_MAX
};
/*
* The incore dquot structure
*/
typedef struct xfs_dquot {
uint dq_flags; /* various flags (XFS_DQ_*) */
struct list_head q_lru; /* global free list of dquots */
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 */
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 */
xfs_qcnt_t q_prealloc_lo_wmark;/* prealloc throttle wmark */
xfs_qcnt_t q_prealloc_hi_wmark;/* prealloc disabled wmark */
int64_t q_low_space[XFS_QLOWSP_MAX];
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;
/*
* 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,
};
/*
* 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 bool 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);
}
static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
{
return mutex_trylock(&dqp->q_qlock);
}
static inline void xfs_dqlock(struct xfs_dquot *dqp)
{
mutex_lock(&dqp->q_qlock);
}
static inline void xfs_dqunlock(struct xfs_dquot *dqp)
{
mutex_unlock(&dqp->q_qlock);
}
static inline int xfs_this_quota_on(struct xfs_mount *mp, int type)
{
switch (type & XFS_DQ_ALLTYPES) {
case XFS_DQ_USER:
return XFS_IS_UQUOTA_ON(mp);
case XFS_DQ_GROUP:
return XFS_IS_GQUOTA_ON(mp);
case XFS_DQ_PROJ:
return XFS_IS_PQUOTA_ON(mp);
default:
return 0;
}
}
static inline xfs_dquot_t *xfs_inode_dquot(struct xfs_inode *ip, int type)
{
switch (type & XFS_DQ_ALLTYPES) {
case XFS_DQ_USER:
return ip->i_udquot;
case XFS_DQ_GROUP:
return ip->i_gdquot;
case XFS_DQ_PROJ:
return ip->i_pdquot;
default:
return NULL;
}
}
/*
* Check whether a dquot is under low free space conditions. We assume the quota
* is enabled and enforced.
*/
static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
{
int64_t freesp;
freesp = be64_to_cpu(dqp->q_core.d_blk_hardlimit) - dqp->q_res_bcount;
if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
return true;
return false;
}
#define XFS_DQ_IS_LOCKED(dqp) (mutex_is_locked(&((dqp)->q_qlock)))
#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)
extern void xfs_qm_dqdestroy(xfs_dquot_t *);
extern int xfs_qm_dqflush(struct xfs_dquot *, struct xfs_buf **);
extern void xfs_qm_dqunpin_wait(xfs_dquot_t *);
extern void xfs_qm_adjust_dqtimers(xfs_mount_t *,
xfs_disk_dquot_t *);
extern void xfs_qm_adjust_dqlimits(struct xfs_mount *,
struct xfs_dquot *);
extern xfs_dqid_t xfs_qm_id_for_quotatype(struct xfs_inode *ip,
uint type);
extern int xfs_qm_dqget(struct xfs_mount *mp, xfs_dqid_t id,
uint type, bool can_alloc,
struct xfs_dquot **dqpp);
extern int xfs_qm_dqget_inode(struct xfs_inode *ip, uint type,
bool can_alloc,
struct xfs_dquot **dqpp);
extern int xfs_qm_dqget_next(struct xfs_mount *mp, xfs_dqid_t id,
uint type, struct xfs_dquot **dqpp);
extern int xfs_qm_dqget_uncached(struct xfs_mount *mp,
xfs_dqid_t id, uint type,
struct xfs_dquot **dqpp);
extern void xfs_qm_dqput(xfs_dquot_t *);
extern void xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
extern void xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
{
xfs_dqlock(dqp);
dqp->q_nrefs++;
xfs_dqunlock(dqp);
return dqp;
}
typedef int (*xfs_qm_dqiterate_fn)(struct xfs_dquot *dq, uint dqtype,
void *priv);
int xfs_qm_dqiterate(struct xfs_mount *mp, uint dqtype,
xfs_qm_dqiterate_fn iter_fn, void *priv);
#endif /* __XFS_DQUOT_H__ */