linux/fs/xfs/xfs_extfree_item.h
Darrick J. Wong dc42375d5f xfs: refactor redo intent item processing
Refactor the EFI intent item recovery (and cancellation) functions
into a general function that scans the AIL and an intent item type
specific handler.  Move the function that recovers a single EFI item
into the extent free item code.  We'll want the generalized function
when we start wiring up more redo item types.

Furthermore, ensure that log recovery only replays the redo items
that were in the AIL prior to recovery by checking the item LSN
against the largest LSN seen during log scanning.  As written this
should never happen, but we can be defensive anyway.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-03 11:23:49 +10:00

105 lines
3.8 KiB
C

/*
* 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 *);
int xfs_efi_recover(struct xfs_mount *mp,
struct xfs_efi_log_item *efip);
#endif /* __XFS_EXTFREE_ITEM_H__ */