[linux.git] / fs / nilfs2 / segbuf.h

/*
 * segbuf.h - NILFS Segment buffer prototypes and definitions
 *
 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will 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 to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Written by Ryusuke Konishi <[email protected]>
 *
 */
#ifndef _NILFS_SEGBUF_H
#define _NILFS_SEGBUF_H

#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/bio.h>
#include <linux/completion.h>
#include <linux/backing-dev.h>

/**
 * struct nilfs_segsum_info - On-memory segment summary
 * @flags: Flags
 * @nfinfo: Number of file information structures
 * @nblocks: Number of blocks included in the partial segment
 * @nsumblk: Number of summary blocks
 * @sumbytes: Byte count of segment summary
 * @nfileblk: Total number of file blocks
 * @seg_seq: Segment sequence number
 * @ctime: Creation time
 * @next: Block number of the next full segment
 */
struct nilfs_segsum_info {
	unsigned int		flags;
	unsigned long		nfinfo;
	unsigned long		nblocks;
	unsigned long		nsumblk;
	unsigned long		sumbytes;
	unsigned long		nfileblk;
	u64			seg_seq;
	time_t			ctime;
	sector_t		next;
};

/* macro for the flags */
#define NILFS_SEG_HAS_SR(sum)    ((sum)->flags & NILFS_SS_SR)
#define NILFS_SEG_LOGBGN(sum)    ((sum)->flags & NILFS_SS_LOGBGN)
#define NILFS_SEG_LOGEND(sum)    ((sum)->flags & NILFS_SS_LOGEND)
#define NILFS_SEG_DSYNC(sum)     ((sum)->flags & NILFS_SS_SYNDT)
#define NILFS_SEG_SIMPLEX(sum) \
	(((sum)->flags & (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) == \
	 (NILFS_SS_LOGBGN | NILFS_SS_LOGEND))

#define NILFS_SEG_EMPTY(sum)	((sum)->nblocks == (sum)->nsumblk)

/**
 * struct nilfs_segment_buffer - Segment buffer
 * @sb_super: back pointer to a superblock struct
 * @sb_list: List head to chain this structure
 * @sb_segent: Pointer for attaching a segment entry
 * @sb_sum: On-memory segment summary
 * @sb_segnum: Index number of the full segment
 * @sb_nextnum: Index number of the next full segment
 * @sb_fseg_start: Start block number of the full segment
 * @sb_fseg_end: End block number of the full segment
 * @sb_pseg_start: Disk block number of partial segment
 * @sb_rest_blocks: Number of residual blocks in the current segment
 * @sb_segsum_buffers: List of buffers for segment summaries
 * @sb_payload_buffers: List of buffers for segment payload
 * @sb_io_error: I/O error status
 */
struct nilfs_segment_buffer {
	struct super_block     *sb_super;
	struct list_head	sb_list;
	struct nilfs_segment_entry *sb_segent;

	/* Segment information */
	struct nilfs_segsum_info sb_sum;
	__u64			sb_segnum;
	__u64			sb_nextnum;
	sector_t		sb_fseg_start, sb_fseg_end;
	sector_t		sb_pseg_start;
	unsigned		sb_rest_blocks;

	/* Buffers */
	struct list_head	sb_segsum_buffers;
	struct list_head	sb_payload_buffers; /* including super root */

	/* io status */
	int			sb_io_error;
};

#define NILFS_LIST_SEGBUF(head)  \
	list_entry((head), struct nilfs_segment_buffer, sb_list)
#define NILFS_NEXT_SEGBUF(segbuf)  NILFS_LIST_SEGBUF((segbuf)->sb_list.next)
#define NILFS_PREV_SEGBUF(segbuf)  NILFS_LIST_SEGBUF((segbuf)->sb_list.prev)
#define NILFS_LAST_SEGBUF(head)    NILFS_LIST_SEGBUF((head)->prev)
#define NILFS_FIRST_SEGBUF(head)   NILFS_LIST_SEGBUF((head)->next)
#define NILFS_SEGBUF_IS_LAST(segbuf, head)  ((segbuf)->sb_list.next == (head))

#define nilfs_for_each_segbuf_before(s, t, h) \
	for ((s) = NILFS_FIRST_SEGBUF(h); (s) != (t); \
	     (s) = NILFS_NEXT_SEGBUF(s))

#define NILFS_SEGBUF_FIRST_BH(head)  \
	(list_entry((head)->next, struct buffer_head, b_assoc_buffers))
#define NILFS_SEGBUF_NEXT_BH(bh)  \
	(list_entry((bh)->b_assoc_buffers.next, struct buffer_head, \
		    b_assoc_buffers))
#define NILFS_SEGBUF_BH_IS_LAST(bh, head)  ((bh)->b_assoc_buffers.next == head)


int __init nilfs_init_segbuf_cache(void);
void nilfs_destroy_segbuf_cache(void);
struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *);
void nilfs_segbuf_free(struct nilfs_segment_buffer *);
int nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long,
		     struct the_nilfs *);
void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64,
				  struct the_nilfs *);
int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned, time_t);
int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *);
int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *,
				struct buffer_head **);
void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *);
void nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *, u32);
void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *, u32);

static inline void
nilfs_segbuf_add_segsum_buffer(struct nilfs_segment_buffer *segbuf,
			       struct buffer_head *bh)
{
	list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_segsum_buffers);
	segbuf->sb_sum.nblocks++;
	segbuf->sb_sum.nsumblk++;
}

static inline void
nilfs_segbuf_add_payload_buffer(struct nilfs_segment_buffer *segbuf,
				struct buffer_head *bh)
{
	list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_payload_buffers);
	segbuf->sb_sum.nblocks++;
}

static inline void
nilfs_segbuf_add_file_buffer(struct nilfs_segment_buffer *segbuf,
			     struct buffer_head *bh)
{
	get_bh(bh);
	nilfs_segbuf_add_payload_buffer(segbuf, bh);
	segbuf->sb_sum.nfileblk++;
}

void nilfs_release_buffers(struct list_head *);

static inline void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
{
	nilfs_release_buffers(&segbuf->sb_segsum_buffers);
	nilfs_release_buffers(&segbuf->sb_payload_buffers);
}

struct nilfs_write_info {
	struct bio	       *bio;
	int 			start, end; /* The region to be submitted */
	int			rest_blocks;
	int			max_pages;
	int			nr_vecs;
	sector_t		blocknr;

	int			nbio;
	atomic_t		err;
	struct completion	bio_event;
				/* completion event of segment write */

	/*
	 * The following fields must be set explicitly
	 */
	struct super_block     *sb;
	struct backing_dev_info *bdi; /* backing dev info */
	struct buffer_head     *bh_sr;
};


void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *,
				struct nilfs_write_info *);
int nilfs_segbuf_write(struct nilfs_segment_buffer *,
		       struct nilfs_write_info *);
int nilfs_segbuf_wait(struct nilfs_segment_buffer *,
		      struct nilfs_write_info *);

#endif /* _NILFS_SEGBUF_H */
Commit	Line	Data
64b5a32e RK	1	/*
	2	* segbuf.h - NILFS Segment buffer prototypes and definitions
	3	*
	4	* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	*
	20	* Written by Ryusuke Konishi <[email protected]>
	21	*
	22	*/
	23	#ifndef _NILFS_SEGBUF_H
	24	#define _NILFS_SEGBUF_H
	25
	26	#include <linux/fs.h>
	27	#include <linux/buffer_head.h>
	28	#include <linux/bio.h>
	29	#include <linux/completion.h>
	30	#include <linux/backing-dev.h>
	31
	32	/**
	33	* struct nilfs_segsum_info - On-memory segment summary
	34	* @flags: Flags
	35	* @nfinfo: Number of file information structures
	36	* @nblocks: Number of blocks included in the partial segment
	37	* @nsumblk: Number of summary blocks
	38	* @sumbytes: Byte count of segment summary
	39	* @nfileblk: Total number of file blocks
	40	* @seg_seq: Segment sequence number
	41	* @ctime: Creation time
	42	* @next: Block number of the next full segment
	43	*/
	44	struct nilfs_segsum_info {
	45	unsigned int flags;
	46	unsigned long nfinfo;
	47	unsigned long nblocks;
	48	unsigned long nsumblk;
	49	unsigned long sumbytes;
	50	unsigned long nfileblk;
	51	u64 seg_seq;
	52	time_t ctime;
	53	sector_t next;
	54	};
	55
	56	/* macro for the flags */
	57	#define NILFS_SEG_HAS_SR(sum) ((sum)->flags & NILFS_SS_SR)
	58	#define NILFS_SEG_LOGBGN(sum) ((sum)->flags & NILFS_SS_LOGBGN)
	59	#define NILFS_SEG_LOGEND(sum) ((sum)->flags & NILFS_SS_LOGEND)
	60	#define NILFS_SEG_DSYNC(sum) ((sum)->flags & NILFS_SS_SYNDT)
	61	#define NILFS_SEG_SIMPLEX(sum) \
	62	(((sum)->flags & (NILFS_SS_LOGBGN \| NILFS_SS_LOGEND)) == \
	63	(NILFS_SS_LOGBGN \| NILFS_SS_LOGEND))
	64
65	#define NILFS_SEG_EMPTY(sum) ((sum)->nblocks == (sum)->nsumblk)
66
67	/**
68	* struct nilfs_segment_buffer - Segment buffer
69	* @sb_super: back pointer to a superblock struct
70	* @sb_list: List head to chain this structure
71	* @sb_segent: Pointer for attaching a segment entry
72	* @sb_sum: On-memory segment summary
73	* @sb_segnum: Index number of the full segment
74	* @sb_nextnum: Index number of the next full segment
75	* @sb_fseg_start: Start block number of the full segment
76	* @sb_fseg_end: End block number of the full segment
77	* @sb_pseg_start: Disk block number of partial segment
78	* @sb_rest_blocks: Number of residual blocks in the current segment
79	* @sb_segsum_buffers: List of buffers for segment summaries
80	* @sb_payload_buffers: List of buffers for segment payload
81	* @sb_io_error: I/O error status
82	*/
83	struct nilfs_segment_buffer {
84	struct super_block *sb_super;
85	struct list_head sb_list;
86	struct nilfs_segment_entry *sb_segent;
87
88	/* Segment information */
89	struct nilfs_segsum_info sb_sum;
90	__u64 sb_segnum;
91	__u64 sb_nextnum;
92	sector_t sb_fseg_start, sb_fseg_end;
93	sector_t sb_pseg_start;
94	unsigned sb_rest_blocks;
95
96	/* Buffers */
97	struct list_head sb_segsum_buffers;
98	struct list_head sb_payload_buffers; /* including super root */
99
100	/* io status */
101	int sb_io_error;
102	};
103
104	#define NILFS_LIST_SEGBUF(head) \
105	list_entry((head), struct nilfs_segment_buffer, sb_list)
106	#define NILFS_NEXT_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.next)
107	#define NILFS_PREV_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.prev)
108	#define NILFS_LAST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->prev)
109	#define NILFS_FIRST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->next)
110	#define NILFS_SEGBUF_IS_LAST(segbuf, head) ((segbuf)->sb_list.next == (head))
111
112	#define nilfs_for_each_segbuf_before(s, t, h) \
113	for ((s) = NILFS_FIRST_SEGBUF(h); (s) != (t); \
114	(s) = NILFS_NEXT_SEGBUF(s))
115
116	#define NILFS_SEGBUF_FIRST_BH(head) \
117	(list_entry((head)->next, struct buffer_head, b_assoc_buffers))
118	#define NILFS_SEGBUF_NEXT_BH(bh) \
119	(list_entry((bh)->b_assoc_buffers.next, struct buffer_head, \
120	b_assoc_buffers))
121	#define NILFS_SEGBUF_BH_IS_LAST(bh, head) ((bh)->b_assoc_buffers.next == head)
122
123
124	int __init nilfs_init_segbuf_cache(void);
125	void nilfs_destroy_segbuf_cache(void);
126	struct nilfs_segment_buffer nilfs_segbuf_new(struct super_block );
127	void nilfs_segbuf_free(struct nilfs_segment_buffer *);
128	int nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long,
129	struct the_nilfs *);
130	void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64,
131	struct the_nilfs *);
132	int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned, time_t);
133	int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *);
134	int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *,
135	struct buffer_head **);
136	void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *);
137	void nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *, u32);
138	void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *, u32);
139
140	static inline void
141	nilfs_segbuf_add_segsum_buffer(struct nilfs_segment_buffer *segbuf,
142	struct buffer_head *bh)
143	{
144	list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_segsum_buffers);
145	segbuf->sb_sum.nblocks++;
146	segbuf->sb_sum.nsumblk++;
147	}
148
149	static inline void
150	nilfs_segbuf_add_payload_buffer(struct nilfs_segment_buffer *segbuf,
151	struct buffer_head *bh)
152	{
153	list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_payload_buffers);
154	segbuf->sb_sum.nblocks++;
155	}
156
157	static inline void
158	nilfs_segbuf_add_file_buffer(struct nilfs_segment_buffer *segbuf,
159	struct buffer_head *bh)
160	{
161	get_bh(bh);
162	nilfs_segbuf_add_payload_buffer(segbuf, bh);
163	segbuf->sb_sum.nfileblk++;
164	}
165
166	void nilfs_release_buffers(struct list_head *);
167
168	static inline void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
169	{
170	nilfs_release_buffers(&segbuf->sb_segsum_buffers);
171	nilfs_release_buffers(&segbuf->sb_payload_buffers);
172	}
173
174	struct nilfs_write_info {
175	struct bio *bio;
176	int start, end; /* The region to be submitted */
177	int rest_blocks;
178	int max_pages;
179	int nr_vecs;
180	sector_t blocknr;
181
182	int nbio;
183	atomic_t err;
184	struct completion bio_event;
185	/* completion event of segment write */
186
187	/*
188	* The following fields must be set explicitly
189	*/
190	struct super_block *sb;
191	struct backing_dev_info bdi; / backing dev info */
192	struct buffer_head *bh_sr;
193	};
194
195
196	void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *,
197	struct nilfs_write_info *);
198	int nilfs_segbuf_write(struct nilfs_segment_buffer *,
199	struct nilfs_write_info *);
200	int nilfs_segbuf_wait(struct nilfs_segment_buffer *,
201	struct nilfs_write_info *);
202
203	#endif /* _NILFS_SEGBUF_H */