xref: /openbmc/linux/fs/xfs/libxfs/xfs_bmap.h (revision bc5aa3a0)
1 /*
2  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #ifndef __XFS_BMAP_H__
19 #define	__XFS_BMAP_H__
20 
21 struct getbmap;
22 struct xfs_bmbt_irec;
23 struct xfs_ifork;
24 struct xfs_inode;
25 struct xfs_mount;
26 struct xfs_trans;
27 
28 extern kmem_zone_t	*xfs_bmap_free_item_zone;
29 
30 /*
31  * Argument structure for xfs_bmap_alloc.
32  */
33 struct xfs_bmalloca {
34 	xfs_fsblock_t		*firstblock; /* i/o first block allocated */
35 	struct xfs_defer_ops	*dfops;	/* bmap freelist */
36 	struct xfs_trans	*tp;	/* transaction pointer */
37 	struct xfs_inode	*ip;	/* incore inode pointer */
38 	struct xfs_bmbt_irec	prev;	/* extent before the new one */
39 	struct xfs_bmbt_irec	got;	/* extent after, or delayed */
40 
41 	xfs_fileoff_t		offset;	/* offset in file filling in */
42 	xfs_extlen_t		length;	/* i/o length asked/allocated */
43 	xfs_fsblock_t		blkno;	/* starting block of new extent */
44 
45 	struct xfs_btree_cur	*cur;	/* btree cursor */
46 	xfs_extnum_t		idx;	/* current extent index */
47 	int			nallocs;/* number of extents alloc'd */
48 	int			logflags;/* flags for transaction logging */
49 
50 	xfs_extlen_t		total;	/* total blocks needed for xaction */
51 	xfs_extlen_t		minlen;	/* minimum allocation size (blocks) */
52 	xfs_extlen_t		minleft; /* amount must be left after alloc */
53 	bool			eof;	/* set if allocating past last extent */
54 	bool			wasdel;	/* replacing a delayed allocation */
55 	bool			aeof;	/* allocated space at eof */
56 	bool			conv;	/* overwriting unwritten extents */
57 	char			userdata;/* userdata mask */
58 	int			flags;
59 };
60 
61 /*
62  * List of extents to be free "later".
63  * The list is kept sorted on xbf_startblock.
64  */
65 struct xfs_extent_free_item
66 {
67 	xfs_fsblock_t		xefi_startblock;/* starting fs block number */
68 	xfs_extlen_t		xefi_blockcount;/* number of blocks in extent */
69 	struct list_head	xefi_list;
70 	struct xfs_owner_info	xefi_oinfo;	/* extent owner */
71 };
72 
73 #define	XFS_BMAP_MAX_NMAP	4
74 
75 /*
76  * Flags for xfs_bmapi_*
77  */
78 #define XFS_BMAPI_ENTIRE	0x001	/* return entire extent, not trimmed */
79 #define XFS_BMAPI_METADATA	0x002	/* mapping metadata not user data */
80 #define XFS_BMAPI_ATTRFORK	0x004	/* use attribute fork not data */
81 #define XFS_BMAPI_PREALLOC	0x008	/* preallocation op: unwritten space */
82 #define XFS_BMAPI_IGSTATE	0x010	/* Ignore state - */
83 					/* combine contig. space */
84 #define XFS_BMAPI_CONTIG	0x020	/* must allocate only one extent */
85 /*
86  * unwritten extent conversion - this needs write cache flushing and no additional
87  * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
88  * from written to unwritten, otherwise convert from unwritten to written.
89  */
90 #define XFS_BMAPI_CONVERT	0x040
91 
92 /*
93  * allocate zeroed extents - this requires all newly allocated user data extents
94  * to be initialised to zero. It will be ignored if XFS_BMAPI_METADATA is set.
95  * Use in conjunction with XFS_BMAPI_CONVERT to convert unwritten extents found
96  * during the allocation range to zeroed written extents.
97  */
98 #define XFS_BMAPI_ZERO		0x080
99 
100 #define XFS_BMAPI_FLAGS \
101 	{ XFS_BMAPI_ENTIRE,	"ENTIRE" }, \
102 	{ XFS_BMAPI_METADATA,	"METADATA" }, \
103 	{ XFS_BMAPI_ATTRFORK,	"ATTRFORK" }, \
104 	{ XFS_BMAPI_PREALLOC,	"PREALLOC" }, \
105 	{ XFS_BMAPI_IGSTATE,	"IGSTATE" }, \
106 	{ XFS_BMAPI_CONTIG,	"CONTIG" }, \
107 	{ XFS_BMAPI_CONVERT,	"CONVERT" }, \
108 	{ XFS_BMAPI_ZERO,	"ZERO" }
109 
110 
111 static inline int xfs_bmapi_aflag(int w)
112 {
113 	return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
114 }
115 
116 /*
117  * Special values for xfs_bmbt_irec_t br_startblock field.
118  */
119 #define	DELAYSTARTBLOCK		((xfs_fsblock_t)-1LL)
120 #define	HOLESTARTBLOCK		((xfs_fsblock_t)-2LL)
121 
122 /*
123  * Flags for xfs_bmap_add_extent*.
124  */
125 #define BMAP_LEFT_CONTIG	(1 << 0)
126 #define BMAP_RIGHT_CONTIG	(1 << 1)
127 #define BMAP_LEFT_FILLING	(1 << 2)
128 #define BMAP_RIGHT_FILLING	(1 << 3)
129 #define BMAP_LEFT_DELAY		(1 << 4)
130 #define BMAP_RIGHT_DELAY	(1 << 5)
131 #define BMAP_LEFT_VALID		(1 << 6)
132 #define BMAP_RIGHT_VALID	(1 << 7)
133 #define BMAP_ATTRFORK		(1 << 8)
134 
135 #define XFS_BMAP_EXT_FLAGS \
136 	{ BMAP_LEFT_CONTIG,	"LC" }, \
137 	{ BMAP_RIGHT_CONTIG,	"RC" }, \
138 	{ BMAP_LEFT_FILLING,	"LF" }, \
139 	{ BMAP_RIGHT_FILLING,	"RF" }, \
140 	{ BMAP_ATTRFORK,	"ATTR" }
141 
142 
143 /*
144  * This macro is used to determine how many extents will be shifted
145  * in one write transaction. We could require two splits,
146  * an extent move on the first and an extent merge on the second,
147  * So it is proper that one extent is shifted inside write transaction
148  * at a time.
149  */
150 #define XFS_BMAP_MAX_SHIFT_EXTENTS	1
151 
152 enum shift_direction {
153 	SHIFT_LEFT = 0,
154 	SHIFT_RIGHT,
155 };
156 
157 #ifdef DEBUG
158 void	xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
159 		int whichfork, unsigned long caller_ip);
160 #define	XFS_BMAP_TRACE_EXLIST(ip,c,w)	\
161 	xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
162 #else
163 #define	XFS_BMAP_TRACE_EXLIST(ip,c,w)
164 #endif
165 
166 int	xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
167 void	xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork);
168 void	xfs_bmap_add_free(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
169 			  xfs_fsblock_t bno, xfs_filblks_t len,
170 			  struct xfs_owner_info *oinfo);
171 void	xfs_bmap_compute_maxlevels(struct xfs_mount *mp, int whichfork);
172 int	xfs_bmap_first_unused(struct xfs_trans *tp, struct xfs_inode *ip,
173 		xfs_extlen_t len, xfs_fileoff_t *unused, int whichfork);
174 int	xfs_bmap_last_before(struct xfs_trans *tp, struct xfs_inode *ip,
175 		xfs_fileoff_t *last_block, int whichfork);
176 int	xfs_bmap_last_offset(struct xfs_inode *ip, xfs_fileoff_t *unused,
177 		int whichfork);
178 int	xfs_bmap_one_block(struct xfs_inode *ip, int whichfork);
179 int	xfs_bmap_read_extents(struct xfs_trans *tp, struct xfs_inode *ip,
180 		int whichfork);
181 int	xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
182 		xfs_filblks_t len, struct xfs_bmbt_irec *mval,
183 		int *nmap, int flags);
184 int	xfs_bmapi_delay(struct xfs_inode *ip, xfs_fileoff_t bno,
185 		xfs_filblks_t len, struct xfs_bmbt_irec *mval,
186 		int *nmap, int flags);
187 int	xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
188 		xfs_fileoff_t bno, xfs_filblks_t len, int flags,
189 		xfs_fsblock_t *firstblock, xfs_extlen_t total,
190 		struct xfs_bmbt_irec *mval, int *nmap,
191 		struct xfs_defer_ops *dfops);
192 int	xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
193 		xfs_fileoff_t bno, xfs_filblks_t len, int flags,
194 		xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
195 		struct xfs_defer_ops *dfops, int *done);
196 int	xfs_check_nostate_extents(struct xfs_ifork *ifp, xfs_extnum_t idx,
197 		xfs_extnum_t num);
198 uint	xfs_default_attroffset(struct xfs_inode *ip);
199 int	xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
200 		xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
201 		int *done, xfs_fileoff_t stop_fsb, xfs_fsblock_t *firstblock,
202 		struct xfs_defer_ops *dfops, enum shift_direction direction,
203 		int num_exts);
204 int	xfs_bmap_split_extent(struct xfs_inode *ip, xfs_fileoff_t split_offset);
205 
206 #endif	/* __XFS_BMAP_H__ */
207