xfs_extfree_item.h
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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_EXTFREE_ITEM_H__
#define __XFS_EXTFREE_ITEM_H__
/* kernel only EFI/EFD definitions */
struct xfs_mount;
struct kmem_zone;
/*
* Max number of extents in fast allocation path.
*/
#define XFS_EFI_MAX_FAST_EXTENTS 16
/*
* Define EFI flag bits. Manipulated by set/clear/test_bit operators.
*/
#define XFS_EFI_RECOVERED 1
/*
* This is the "extent free intention" log item. It is used to log the fact
* that some extents need to be free. It is used in conjunction with the
* "extent free done" log item described below.
*
* The EFI is reference counted so that it is not freed prior to both the EFI
* and EFD being committed and unpinned. This ensures the EFI is inserted into
* the AIL even in the event of out of order EFI/EFD processing. In other words,
* an EFI is born with two references:
*
* 1.) an EFI held reference to track EFI AIL insertion
* 2.) an EFD held reference to track EFD commit
*
* On allocation, both references are the responsibility of the caller. Once the
* EFI is added to and dirtied in a transaction, ownership of reference one
* transfers to the transaction. The reference is dropped once the EFI is
* inserted to the AIL or in the event of failure along the way (e.g., commit
* failure, log I/O error, etc.). Note that the caller remains responsible for
* the EFD reference under all circumstances to this point. The caller has no
* means to detect failure once the transaction is committed, however.
* Therefore, an EFD is required after this point, even in the event of
* unrelated failure.
*
* Once an EFD is allocated and dirtied in a transaction, reference two
* transfers to the transaction. The EFD reference is dropped once it reaches
* the unpin handler. Similar to the EFI, the reference also drops in the event
* of commit failure or log I/O errors. Note that the EFD is not inserted in the
* AIL, so at this point both the EFI and EFD are freed.
*/
typedef struct xfs_efi_log_item {
xfs_log_item_t efi_item;
atomic_t efi_refcount;
atomic_t efi_next_extent;
unsigned long efi_flags; /* misc flags */
xfs_efi_log_format_t efi_format;
} xfs_efi_log_item_t;
/*
* This is the "extent free done" log item. It is used to log
* the fact that some extents earlier mentioned in an efi item
* have been freed.
*/
typedef struct xfs_efd_log_item {
xfs_log_item_t efd_item;
xfs_efi_log_item_t *efd_efip;
uint efd_next_extent;
xfs_efd_log_format_t efd_format;
} xfs_efd_log_item_t;
/*
* Max number of extents in fast allocation path.
*/
#define XFS_EFD_MAX_FAST_EXTENTS 16
extern struct kmem_zone *xfs_efi_zone;
extern struct kmem_zone *xfs_efd_zone;
xfs_efi_log_item_t *xfs_efi_init(struct xfs_mount *, uint);
xfs_efd_log_item_t *xfs_efd_init(struct xfs_mount *, xfs_efi_log_item_t *,
uint);
int xfs_efi_copy_format(xfs_log_iovec_t *buf,
xfs_efi_log_format_t *dst_efi_fmt);
void xfs_efi_item_free(xfs_efi_log_item_t *);
void xfs_efi_release(struct xfs_efi_log_item *);
#endif /* __XFS_EXTFREE_ITEM_H__ */