alistair23-linux/include/linux/quotaops.h
Jan Kara 0ff5af8340 quota: quota core changes for quotaon on remount
Currently, we just turn quotas off on remount of filesystem to read-only
state.  The patch below adds necessary framework so that we can turn quotas
off on remount RO but we are able to automatically reenable them again when
filesystem is remounted to RW state.  All we need to do is to keep references
to inodes of quota files when remounting RO and using these references to
reenable quotas when remounting RW.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:33 -07:00

292 lines
8 KiB
C

/*
* 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)
#define DQUOT_INIT(inode) do { } while(0)
#define DQUOT_DROP(inode) do { } while(0)
#define DQUOT_ALLOC_INODE(inode) (0)
#define DQUOT_FREE_INODE(inode) do { } while(0)
#define DQUOT_SYNC(sb) do { } while(0)
#define DQUOT_OFF(sb, remount) (0)
#define DQUOT_ON_REMOUNT(sb) (0)
#define DQUOT_TRANSFER(inode, iattr) (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_ */