include/linux/quotaops.h

/*
 * Definitions for diskquota-operations. When diskquota is configured these
 * macros expand to the right source-code.
 *
 * Author:  Marco van Wieringen <mvw@planets.elm.net>
 *
 * Version: $Id: quotaops.h,v 1.2 1998/01/15 16:22:26 ecd Exp $
 *
 */
#ifndef _LINUX_QUOTAOPS_
#define _LINUX_QUOTAOPS_

#include <linux/smp_lock.h>

#include <linux/fs.h>

#if defined(CONFIG_QUOTA)

/*
 * declaration of quota_function calls in kernel.
 */
extern void sync_dquots(struct super_block *sb, int type);

extern int dquot_initialize(struct inode *inode, int type);
extern int dquot_drop(struct inode *inode);

extern int dquot_alloc_space(struct inode *inode, qsize_t number, int prealloc);
extern int dquot_alloc_inode(const struct inode *inode, unsigned long number);

extern int dquot_free_space(struct inode *inode, qsize_t number);
extern int dquot_free_inode(const struct inode *inode, unsigned long number);

extern int dquot_transfer(struct inode *inode, struct iattr *iattr);
extern int dquot_commit(struct dquot *dquot);
extern int dquot_acquire(struct dquot *dquot);
extern int dquot_release(struct dquot *dquot);
extern int dquot_commit_info(struct super_block *sb, int type);
extern int dquot_mark_dquot_dirty(struct dquot *dquot);

extern int vfs_quota_on(struct super_block *sb, int type, int format_id,
		char *path, int remount);
extern int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
		int format_id, int type);
extern int vfs_quota_off(struct super_block *sb, int type, int remount);
extern int vfs_quota_sync(struct super_block *sb, int type);
extern int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii);
extern int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii);
extern int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di);
extern int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di);

/*
 * Operations supported for diskquotas.
 */
extern struct dquot_operations dquot_operations;
extern struct quotactl_ops vfs_quotactl_ops;

#define sb_dquot_ops (&dquot_operations)
#define sb_quotactl_ops (&vfs_quotactl_ops)

/* It is better to call this function outside of any transaction as it might
 * need a lot of space in journal for dquot structure allocation. */
static inline void DQUOT_INIT(struct inode *inode)
{
	BUG_ON(!inode->i_sb);
	if (sb_any_quota_enabled(inode->i_sb) && !IS_NOQUOTA(inode))
		inode->i_sb->dq_op->initialize(inode, -1);
}

/* The same as with DQUOT_INIT */
static inline void DQUOT_DROP(struct inode *inode)
{
	/* Here we can get arbitrary inode from clear_inode() so we have
	 * to be careful. OTOH we don't need locking as quota operations
	 * are allowed to change only at mount time */
	if (!IS_NOQUOTA(inode) && inode->i_sb && inode->i_sb->dq_op
	    && inode->i_sb->dq_op->drop) {
		int cnt;
		/* Test before calling to rule out calls from proc and such
                 * where we are not allowed to block. Note that this is
		 * actually reliable test even without the lock - the caller
		 * must assure that nobody can come after the DQUOT_DROP and
		 * add quota pointers back anyway */
		for (cnt = 0; cnt < MAXQUOTAS; cnt++)
			if (inode->i_dquot[cnt] != NODQUOT)
				break;
		if (cnt < MAXQUOTAS)
			inode->i_sb->dq_op->drop(inode);
	}
}

/* The following allocation/freeing/transfer functions *must* be called inside
 * a transaction (deadlocks possible otherwise) */
static inline int DQUOT_PREALLOC_SPACE_NODIRTY(struct inode *inode, qsize_t nr)
{
	if (sb_any_quota_enabled(inode->i_sb)) {
		/* Used space is updated in alloc_space() */
		if (inode->i_sb->dq_op->alloc_space(inode, nr, 1) == NO_QUOTA)
			return 1;
	}
	else
		inode_add_bytes(inode, nr);
	return 0;
}

static inline int DQUOT_PREALLOC_SPACE(struct inode *inode, qsize_t nr)
{
	int ret;
        if (!(ret =  DQUOT_PREALLOC_SPACE_NODIRTY(inode, nr)))
		mark_inode_dirty(inode);
	return ret;
}

static inline int DQUOT_ALLOC_SPACE_NODIRTY(struct inode *inode, qsize_t nr)
{
	if (sb_any_quota_enabled(inode->i_sb)) {
		/* Used space is updated in alloc_space() */
		if (inode->i_sb->dq_op->alloc_space(inode, nr, 0) == NO_QUOTA)
			return 1;
	}
	else
		inode_add_bytes(inode, nr);
	return 0;
}

static inline int DQUOT_ALLOC_SPACE(struct inode *inode, qsize_t nr)
{
	int ret;
	if (!(ret = DQUOT_ALLOC_SPACE_NODIRTY(inode, nr)))
		mark_inode_dirty(inode);
	return ret;
}

static inline int DQUOT_ALLOC_INODE(struct inode *inode)
{
	if (sb_any_quota_enabled(inode->i_sb)) {
		DQUOT_INIT(inode);
		if (inode->i_sb->dq_op->alloc_inode(inode, 1) == NO_QUOTA)
			return 1;
	}
	return 0;
}

static inline void DQUOT_FREE_SPACE_NODIRTY(struct inode *inode, qsize_t nr)
{
	if (sb_any_quota_enabled(inode->i_sb))
		inode->i_sb->dq_op->free_space(inode, nr);
	else
		inode_sub_bytes(inode, nr);
}

static inline void DQUOT_FREE_SPACE(struct inode *inode, qsize_t nr)
{
	DQUOT_FREE_SPACE_NODIRTY(inode, nr);
	mark_inode_dirty(inode);
}

static inline void DQUOT_FREE_INODE(struct inode *inode)
{
	if (sb_any_quota_enabled(inode->i_sb))
		inode->i_sb->dq_op->free_inode(inode, 1);
}

static inline int DQUOT_TRANSFER(struct inode *inode, struct iattr *iattr)
{
	if (sb_any_quota_enabled(inode->i_sb) && !IS_NOQUOTA(inode)) {
		DQUOT_INIT(inode);
		if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA)
			return 1;
	}
	return 0;
}

/* The following two functions cannot be called inside a transaction */
static inline void DQUOT_SYNC(struct super_block *sb)
{
	sync_dquots(sb, -1);
}

static inline int DQUOT_OFF(struct super_block *sb, int remount)
{
	int ret = -ENOSYS;

	if (sb->s_qcop && sb->s_qcop->quota_off)
		ret = sb->s_qcop->quota_off(sb, -1, remount);
	return ret;
}

static inline int DQUOT_ON_REMOUNT(struct super_block *sb)
{
	int cnt;
	int ret = 0, err;

	if (!sb->s_qcop || !sb->s_qcop->quota_on)
		return -ENOSYS;
	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
		err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1);
		if (err < 0 && !ret)
			ret = err;
	}
	return ret;
}

#else

/*
 * NO-OP when quota not configured.
 */
#define sb_dquot_ops				(NULL)
#define sb_quotactl_ops				(NULL)

static inline void DQUOT_INIT(struct inode *inode)
{
}

static inline void DQUOT_DROP(struct inode *inode)
{
}

static inline int DQUOT_ALLOC_INODE(struct inode *inode)
{
	return 0;
}

static inline void DQUOT_FREE_INODE(struct inode *inode)
{
}

static inline void DQUOT_SYNC(struct super_block *sb)
{
}

static inline int DQUOT_OFF(struct super_block *sb, int remount)
{
	return 0;
}

static inline int DQUOT_ON_REMOUNT(struct super_block *sb)
{
	return 0;
}

static inline int DQUOT_TRANSFER(struct inode *inode, struct iattr *iattr)
{
	return 0;
}

static inline int DQUOT_PREALLOC_SPACE_NODIRTY(struct inode *inode, qsize_t nr)
{
	inode_add_bytes(inode, nr);
	return 0;
}

static inline int DQUOT_PREALLOC_SPACE(struct inode *inode, qsize_t nr)
{
	DQUOT_PREALLOC_SPACE_NODIRTY(inode, nr);
	mark_inode_dirty(inode);
	return 0;
}

static inline int DQUOT_ALLOC_SPACE_NODIRTY(struct inode *inode, qsize_t nr)
{
	inode_add_bytes(inode, nr);
	return 0;
}

static inline int DQUOT_ALLOC_SPACE(struct inode *inode, qsize_t nr)
{
	DQUOT_ALLOC_SPACE_NODIRTY(inode, nr);
	mark_inode_dirty(inode);
	return 0;
}

static inline void DQUOT_FREE_SPACE_NODIRTY(struct inode *inode, qsize_t nr)
{
	inode_sub_bytes(inode, nr);
}

static inline void DQUOT_FREE_SPACE(struct inode *inode, qsize_t nr)
{
	DQUOT_FREE_SPACE_NODIRTY(inode, nr);
	mark_inode_dirty(inode);
}	

#endif /* CONFIG_QUOTA */

static inline int DQUOT_PREALLOC_BLOCK_NODIRTY(struct inode *inode, qsize_t nr)
{
	return DQUOT_PREALLOC_SPACE_NODIRTY(inode,
			nr << inode->i_sb->s_blocksize_bits);
}

static inline int DQUOT_PREALLOC_BLOCK(struct inode *inode, qsize_t nr)
{
	return DQUOT_PREALLOC_SPACE(inode,
			nr << inode->i_sb->s_blocksize_bits);
}

static inline int DQUOT_ALLOC_BLOCK_NODIRTY(struct inode *inode, qsize_t nr)
{
	return DQUOT_ALLOC_SPACE_NODIRTY(inode,
			nr << inode->i_sb->s_blocksize_bits);
}

static inline int DQUOT_ALLOC_BLOCK(struct inode *inode, qsize_t nr)
{
	return DQUOT_ALLOC_SPACE(inode,
			nr << inode->i_sb->s_blocksize_bits);
}

static inline void DQUOT_FREE_BLOCK_NODIRTY(struct inode *inode, qsize_t nr)
{
	DQUOT_FREE_SPACE_NODIRTY(inode, nr << inode->i_sb->s_blocksize_bits);
}

static inline void DQUOT_FREE_BLOCK(struct inode *inode, qsize_t nr)
{
	DQUOT_FREE_SPACE(inode, nr << inode->i_sb->s_blocksize_bits);
}

#endif /* _LINUX_QUOTAOPS_ */