linux/fs/xfs/xfs_buf_item.h
Dave Chinner 61fe135c1d xfs: buffer type overruns blf_flags field
The buffer type passed to log recvoery in the buffer log item
overruns the blf_flags field. I had assumed that flags field was a
32 bit value, and it turns out it is a unisgned short. Therefore
having 19 flags doesn't really work.

Convert the buffer type field to numeric value, and use the top 5
bits of the flags field for it. We currently have 17 types of
buffers, so using 5 bits gives us plenty of room for expansion in
future....

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-04-27 13:01:58 -05:00

173 lines
5.4 KiB
C

/*
* Copyright (c) 2000-2001,2005 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_BUF_ITEM_H__
#define __XFS_BUF_ITEM_H__
extern kmem_zone_t *xfs_buf_item_zone;
/*
* This flag indicates that the buffer contains on disk inodes
* and requires special recovery handling.
*/
#define XFS_BLF_INODE_BUF (1<<0)
/*
* This flag indicates that the buffer should not be replayed
* during recovery because its blocks are being freed.
*/
#define XFS_BLF_CANCEL (1<<1)
/*
* This flag indicates that the buffer contains on disk
* user or group dquots and may require special recovery handling.
*/
#define XFS_BLF_UDQUOT_BUF (1<<2)
#define XFS_BLF_PDQUOT_BUF (1<<3)
#define XFS_BLF_GDQUOT_BUF (1<<4)
#define XFS_BLF_CHUNK 128
#define XFS_BLF_SHIFT 7
#define BIT_TO_WORD_SHIFT 5
#define NBWORD (NBBY * sizeof(unsigned int))
/*
* This is the structure used to lay out a buf log item in the
* log. The data map describes which 128 byte chunks of the buffer
* have been logged.
*/
#define XFS_BLF_DATAMAP_SIZE ((XFS_MAX_BLOCKSIZE / XFS_BLF_CHUNK) / NBWORD)
typedef struct xfs_buf_log_format {
unsigned short blf_type; /* buf log item type indicator */
unsigned short blf_size; /* size of this item */
ushort blf_flags; /* misc state */
ushort blf_len; /* number of blocks in this buf */
__int64_t blf_blkno; /* starting blkno of this buf */
unsigned int blf_map_size; /* used size of data bitmap in words */
unsigned int blf_data_map[XFS_BLF_DATAMAP_SIZE]; /* dirty bitmap */
} xfs_buf_log_format_t;
/*
* All buffers now need to tell recovery where the magic number
* is so that it can verify and calculate the CRCs on the buffer correctly
* once the changes have been replayed into the buffer.
*
* The type value is held in the upper 5 bits of the blf_flags field, which is
* an unsigned 16 bit field. Hence we need to shift it 11 bits up and down.
*/
#define XFS_BLFT_BITS 5
#define XFS_BLFT_SHIFT 11
#define XFS_BLFT_MASK (((1 << XFS_BLFT_BITS) - 1) << XFS_BLFT_SHIFT)
enum xfs_blft {
XFS_BLFT_UNKNOWN_BUF = 0,
XFS_BLFT_UDQUOT_BUF,
XFS_BLFT_PDQUOT_BUF,
XFS_BLFT_GDQUOT_BUF,
XFS_BLFT_BTREE_BUF,
XFS_BLFT_AGF_BUF,
XFS_BLFT_AGFL_BUF,
XFS_BLFT_AGI_BUF,
XFS_BLFT_DINO_BUF,
XFS_BLFT_SYMLINK_BUF,
XFS_BLFT_DIR_BLOCK_BUF,
XFS_BLFT_DIR_DATA_BUF,
XFS_BLFT_DIR_FREE_BUF,
XFS_BLFT_DIR_LEAF1_BUF,
XFS_BLFT_DIR_LEAFN_BUF,
XFS_BLFT_DA_NODE_BUF,
XFS_BLFT_ATTR_LEAF_BUF,
XFS_BLFT_ATTR_RMT_BUF,
XFS_BLFT_SB_BUF,
XFS_BLFT_MAX_BUF = (1 << XFS_BLFT_BITS),
};
static inline void
xfs_blft_to_flags(struct xfs_buf_log_format *blf, enum xfs_blft type)
{
ASSERT(type > XFS_BLFT_UNKNOWN_BUF && type < XFS_BLFT_MAX_BUF);
blf->blf_flags &= ~XFS_BLFT_MASK;
blf->blf_flags |= ((type << XFS_BLFT_SHIFT) & XFS_BLFT_MASK);
}
static inline __uint16_t
xfs_blft_from_flags(struct xfs_buf_log_format *blf)
{
return (blf->blf_flags & XFS_BLFT_MASK) >> XFS_BLFT_SHIFT;
}
/*
* buf log item flags
*/
#define XFS_BLI_HOLD 0x01
#define XFS_BLI_DIRTY 0x02
#define XFS_BLI_STALE 0x04
#define XFS_BLI_LOGGED 0x08
#define XFS_BLI_INODE_ALLOC_BUF 0x10
#define XFS_BLI_STALE_INODE 0x20
#define XFS_BLI_INODE_BUF 0x40
#define XFS_BLI_FLAGS \
{ XFS_BLI_HOLD, "HOLD" }, \
{ XFS_BLI_DIRTY, "DIRTY" }, \
{ XFS_BLI_STALE, "STALE" }, \
{ XFS_BLI_LOGGED, "LOGGED" }, \
{ XFS_BLI_INODE_ALLOC_BUF, "INODE_ALLOC" }, \
{ XFS_BLI_STALE_INODE, "STALE_INODE" }, \
{ XFS_BLI_INODE_BUF, "INODE_BUF" }
#ifdef __KERNEL__
struct xfs_buf;
struct xfs_mount;
struct xfs_buf_log_item;
/*
* This is the in core log item structure used to track information
* needed to log buffers. It tracks how many times the lock has been
* locked, and which 128 byte chunks of the buffer are dirty.
*/
typedef struct xfs_buf_log_item {
xfs_log_item_t bli_item; /* common item structure */
struct xfs_buf *bli_buf; /* real buffer pointer */
unsigned int bli_flags; /* misc flags */
unsigned int bli_recur; /* lock recursion count */
atomic_t bli_refcount; /* cnt of tp refs */
int bli_format_count; /* count of headers */
struct xfs_buf_log_format *bli_formats; /* array of in-log header ptrs */
struct xfs_buf_log_format __bli_format; /* embedded in-log header */
} xfs_buf_log_item_t;
void xfs_buf_item_init(struct xfs_buf *, struct xfs_mount *);
void xfs_buf_item_relse(struct xfs_buf *);
void xfs_buf_item_log(xfs_buf_log_item_t *, uint, uint);
uint xfs_buf_item_dirty(xfs_buf_log_item_t *);
void xfs_buf_attach_iodone(struct xfs_buf *,
void(*)(struct xfs_buf *, xfs_log_item_t *),
xfs_log_item_t *);
void xfs_buf_iodone_callbacks(struct xfs_buf *);
void xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *);
void xfs_trans_buf_set_type(struct xfs_trans *, struct xfs_buf *,
enum xfs_blft);
void xfs_trans_buf_copy_type(struct xfs_buf *dst_bp, struct xfs_buf *src_bp);
#endif /* __KERNEL__ */
#endif /* __XFS_BUF_ITEM_H__ */