![Al Viro](/assets/img/avatar_default.png)
is check if semaphore is actually locked, which can be trivially done in portable way. Code gets more reabable, while we are at it... SGI-PV: 953915 SGI-Modid: xfs-linux-melb:xfs-kern:26274a Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Nathan Scott <nathans@sgi.com>
191 lines
6.6 KiB
C
191 lines
6.6 KiB
C
/*
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* Copyright (c) 2000-2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef __XFS_DQUOT_H__
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#define __XFS_DQUOT_H__
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/*
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* Dquots are structures that hold quota information about a user or a group,
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* much like inodes are for files. In fact, dquots share many characteristics
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* with inodes. However, dquots can also be a centralized resource, relative
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* to a collection of inodes. In this respect, dquots share some characteristics
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* of the superblock.
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* XFS dquots exploit both those in its algorithms. They make every attempt
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* to not be a bottleneck when quotas are on and have minimal impact, if any,
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* when quotas are off.
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*/
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/*
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* The hash chain headers (hash buckets)
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*/
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typedef struct xfs_dqhash {
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struct xfs_dquot *qh_next;
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mutex_t qh_lock;
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uint qh_version; /* ever increasing version */
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uint qh_nelems; /* number of dquots on the list */
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} xfs_dqhash_t;
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typedef struct xfs_dqlink {
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struct xfs_dquot *ql_next; /* forward link */
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struct xfs_dquot **ql_prevp; /* pointer to prev ql_next */
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} xfs_dqlink_t;
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struct xfs_mount;
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struct xfs_trans;
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/*
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* This is the marker which is designed to occupy the first few
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* bytes of the xfs_dquot_t structure. Even inside this, the freelist pointers
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* must come first.
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* This serves as the marker ("sentinel") when we have to restart list
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* iterations because of locking considerations.
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*/
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typedef struct xfs_dqmarker {
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struct xfs_dquot*dqm_flnext; /* link to freelist: must be first */
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struct xfs_dquot*dqm_flprev;
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xfs_dqlink_t dqm_mplist; /* link to mount's list of dquots */
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xfs_dqlink_t dqm_hashlist; /* link to the hash chain */
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uint dqm_flags; /* various flags (XFS_DQ_*) */
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} xfs_dqmarker_t;
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/*
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* The incore dquot structure
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*/
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typedef struct xfs_dquot {
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xfs_dqmarker_t q_lists; /* list ptrs, q_flags (marker) */
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xfs_dqhash_t *q_hash; /* the hashchain header */
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struct xfs_mount*q_mount; /* filesystem this relates to */
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struct xfs_trans*q_transp; /* trans this belongs to currently */
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uint q_nrefs; /* # active refs from inodes */
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xfs_daddr_t q_blkno; /* blkno of dquot buffer */
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int q_bufoffset; /* off of dq in buffer (# dquots) */
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xfs_fileoff_t q_fileoffset; /* offset in quotas file */
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struct xfs_dquot*q_gdquot; /* group dquot, hint only */
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xfs_disk_dquot_t q_core; /* actual usage & quotas */
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xfs_dq_logitem_t q_logitem; /* dquot log item */
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xfs_qcnt_t q_res_bcount; /* total regular nblks used+reserved */
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xfs_qcnt_t q_res_icount; /* total inos allocd+reserved */
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xfs_qcnt_t q_res_rtbcount;/* total realtime blks used+reserved */
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mutex_t q_qlock; /* quota lock */
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sema_t q_flock; /* flush lock */
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uint q_pincount; /* pin count for this dquot */
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sv_t q_pinwait; /* sync var for pinning */
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#ifdef XFS_DQUOT_TRACE
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struct ktrace *q_trace; /* trace header structure */
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#endif
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} xfs_dquot_t;
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#define dq_flnext q_lists.dqm_flnext
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#define dq_flprev q_lists.dqm_flprev
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#define dq_mplist q_lists.dqm_mplist
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#define dq_hashlist q_lists.dqm_hashlist
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#define dq_flags q_lists.dqm_flags
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#define XFS_DQHOLD(dqp) ((dqp)->q_nrefs++)
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#ifdef DEBUG
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static inline int
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XFS_DQ_IS_LOCKED(xfs_dquot_t *dqp)
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{
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if (mutex_trylock(&dqp->q_qlock)) {
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mutex_unlock(&dqp->q_qlock);
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return 0;
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}
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return 1;
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}
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#endif
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/*
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* The following three routines simply manage the q_flock
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* semaphore embedded in the dquot. This semaphore synchronizes
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* processes attempting to flush the in-core dquot back to disk.
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*/
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#define xfs_dqflock(dqp) { psema(&((dqp)->q_flock), PINOD | PRECALC);\
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(dqp)->dq_flags |= XFS_DQ_FLOCKED; }
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#define xfs_dqfunlock(dqp) { ASSERT(issemalocked(&((dqp)->q_flock))); \
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vsema(&((dqp)->q_flock)); \
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(dqp)->dq_flags &= ~(XFS_DQ_FLOCKED); }
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#define XFS_DQ_PINLOCK(dqp) mutex_spinlock( \
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&(XFS_DQ_TO_QINF(dqp)->qi_pinlock))
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#define XFS_DQ_PINUNLOCK(dqp, s) mutex_spinunlock( \
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&(XFS_DQ_TO_QINF(dqp)->qi_pinlock), s)
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#define XFS_DQ_IS_FLUSH_LOCKED(dqp) (issemalocked(&((dqp)->q_flock)))
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#define XFS_DQ_IS_ON_FREELIST(dqp) ((dqp)->dq_flnext != (dqp))
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#define XFS_DQ_IS_DIRTY(dqp) ((dqp)->dq_flags & XFS_DQ_DIRTY)
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#define XFS_QM_ISUDQ(dqp) ((dqp)->dq_flags & XFS_DQ_USER)
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#define XFS_QM_ISPDQ(dqp) ((dqp)->dq_flags & XFS_DQ_PROJ)
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#define XFS_QM_ISGDQ(dqp) ((dqp)->dq_flags & XFS_DQ_GROUP)
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#define XFS_DQ_TO_QINF(dqp) ((dqp)->q_mount->m_quotainfo)
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#define XFS_DQ_TO_QIP(dqp) (XFS_QM_ISUDQ(dqp) ? \
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XFS_DQ_TO_QINF(dqp)->qi_uquotaip : \
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XFS_DQ_TO_QINF(dqp)->qi_gquotaip)
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#define XFS_IS_THIS_QUOTA_OFF(d) (! (XFS_QM_ISUDQ(d) ? \
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(XFS_IS_UQUOTA_ON((d)->q_mount)) : \
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(XFS_IS_OQUOTA_ON((d)->q_mount))))
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#ifdef XFS_DQUOT_TRACE
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/*
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* Dquot Tracing stuff.
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*/
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#define DQUOT_TRACE_SIZE 64
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#define DQUOT_KTRACE_ENTRY 1
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extern void __xfs_dqtrace_entry(xfs_dquot_t *dqp, char *func,
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void *, xfs_inode_t *);
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#define xfs_dqtrace_entry_ino(a,b,ip) \
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__xfs_dqtrace_entry((a), (b), (void*)__return_address, (ip))
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#define xfs_dqtrace_entry(a,b) \
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__xfs_dqtrace_entry((a), (b), (void*)__return_address, NULL)
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#else
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#define xfs_dqtrace_entry(a,b)
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#define xfs_dqtrace_entry_ino(a,b,ip)
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#endif
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#ifdef QUOTADEBUG
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extern void xfs_qm_dqprint(xfs_dquot_t *);
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#else
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#define xfs_qm_dqprint(a)
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#endif
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extern void xfs_qm_dqdestroy(xfs_dquot_t *);
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extern int xfs_qm_dqflush(xfs_dquot_t *, uint);
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extern int xfs_qm_dqpurge(xfs_dquot_t *, uint);
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extern void xfs_qm_dqunpin_wait(xfs_dquot_t *);
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extern int xfs_qm_dqlock_nowait(xfs_dquot_t *);
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extern int xfs_qm_dqflock_nowait(xfs_dquot_t *);
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extern void xfs_qm_dqflock_pushbuf_wait(xfs_dquot_t *dqp);
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extern void xfs_qm_adjust_dqtimers(xfs_mount_t *,
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xfs_disk_dquot_t *);
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extern void xfs_qm_adjust_dqlimits(xfs_mount_t *,
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xfs_disk_dquot_t *);
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extern int xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
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xfs_dqid_t, uint, uint, xfs_dquot_t **);
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extern void xfs_qm_dqput(xfs_dquot_t *);
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extern void xfs_qm_dqrele(xfs_dquot_t *);
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extern void xfs_dqlock(xfs_dquot_t *);
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extern void xfs_dqlock2(xfs_dquot_t *, xfs_dquot_t *);
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extern void xfs_dqunlock(xfs_dquot_t *);
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extern void xfs_dqunlock_nonotify(xfs_dquot_t *);
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#endif /* __XFS_DQUOT_H__ */
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