xref: /openbmc/linux/fs/xfs/libxfs/xfs_bmap.h (revision 77a87824)
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_bmap_free	*flist;	/* 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_bmap_free_item
66 {
67 	xfs_fsblock_t		xbfi_startblock;/* starting fs block number */
68 	xfs_extlen_t		xbfi_blockcount;/* number of blocks in extent */
69 	struct list_head	xbfi_list;
70 };
71 
72 /*
73  * Header for free extent list.
74  *
75  * xbf_low is used by the allocator to activate the lowspace algorithm -
76  * when free space is running low the extent allocator may choose to
77  * allocate an extent from an AG without leaving sufficient space for
78  * a btree split when inserting the new extent.  In this case the allocator
79  * will enable the lowspace algorithm which is supposed to allow further
80  * allocations (such as btree splits and newroots) to allocate from
81  * sequential AGs.  In order to avoid locking AGs out of order the lowspace
82  * algorithm will start searching for free space from AG 0.  If the correct
83  * transaction reservations have been made then this algorithm will eventually
84  * find all the space it needs.
85  */
86 typedef	struct xfs_bmap_free
87 {
88 	struct list_head	xbf_flist;	/* list of to-be-free extents */
89 	int			xbf_count;	/* count of items on list */
90 	int			xbf_low;	/* alloc in low mode */
91 } xfs_bmap_free_t;
92 
93 #define	XFS_BMAP_MAX_NMAP	4
94 
95 /*
96  * Flags for xfs_bmapi_*
97  */
98 #define XFS_BMAPI_ENTIRE	0x001	/* return entire extent, not trimmed */
99 #define XFS_BMAPI_METADATA	0x002	/* mapping metadata not user data */
100 #define XFS_BMAPI_ATTRFORK	0x004	/* use attribute fork not data */
101 #define XFS_BMAPI_PREALLOC	0x008	/* preallocation op: unwritten space */
102 #define XFS_BMAPI_IGSTATE	0x010	/* Ignore state - */
103 					/* combine contig. space */
104 #define XFS_BMAPI_CONTIG	0x020	/* must allocate only one extent */
105 /*
106  * unwritten extent conversion - this needs write cache flushing and no additional
107  * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
108  * from written to unwritten, otherwise convert from unwritten to written.
109  */
110 #define XFS_BMAPI_CONVERT	0x040
111 
112 /*
113  * allocate zeroed extents - this requires all newly allocated user data extents
114  * to be initialised to zero. It will be ignored if XFS_BMAPI_METADATA is set.
115  * Use in conjunction with XFS_BMAPI_CONVERT to convert unwritten extents found
116  * during the allocation range to zeroed written extents.
117  */
118 #define XFS_BMAPI_ZERO		0x080
119 
120 #define XFS_BMAPI_FLAGS \
121 	{ XFS_BMAPI_ENTIRE,	"ENTIRE" }, \
122 	{ XFS_BMAPI_METADATA,	"METADATA" }, \
123 	{ XFS_BMAPI_ATTRFORK,	"ATTRFORK" }, \
124 	{ XFS_BMAPI_PREALLOC,	"PREALLOC" }, \
125 	{ XFS_BMAPI_IGSTATE,	"IGSTATE" }, \
126 	{ XFS_BMAPI_CONTIG,	"CONTIG" }, \
127 	{ XFS_BMAPI_CONVERT,	"CONVERT" }, \
128 	{ XFS_BMAPI_ZERO,	"ZERO" }
129 
130 
131 static inline int xfs_bmapi_aflag(int w)
132 {
133 	return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
134 }
135 
136 /*
137  * Special values for xfs_bmbt_irec_t br_startblock field.
138  */
139 #define	DELAYSTARTBLOCK		((xfs_fsblock_t)-1LL)
140 #define	HOLESTARTBLOCK		((xfs_fsblock_t)-2LL)
141 
142 static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
143 {
144 	INIT_LIST_HEAD(&flp->xbf_flist);
145 	flp->xbf_count = 0;
146 	flp->xbf_low = 0;
147 	*fbp = NULLFSBLOCK;
148 }
149 
150 /*
151  * Flags for xfs_bmap_add_extent*.
152  */
153 #define BMAP_LEFT_CONTIG	(1 << 0)
154 #define BMAP_RIGHT_CONTIG	(1 << 1)
155 #define BMAP_LEFT_FILLING	(1 << 2)
156 #define BMAP_RIGHT_FILLING	(1 << 3)
157 #define BMAP_LEFT_DELAY		(1 << 4)
158 #define BMAP_RIGHT_DELAY	(1 << 5)
159 #define BMAP_LEFT_VALID		(1 << 6)
160 #define BMAP_RIGHT_VALID	(1 << 7)
161 #define BMAP_ATTRFORK		(1 << 8)
162 
163 #define XFS_BMAP_EXT_FLAGS \
164 	{ BMAP_LEFT_CONTIG,	"LC" }, \
165 	{ BMAP_RIGHT_CONTIG,	"RC" }, \
166 	{ BMAP_LEFT_FILLING,	"LF" }, \
167 	{ BMAP_RIGHT_FILLING,	"RF" }, \
168 	{ BMAP_ATTRFORK,	"ATTR" }
169 
170 
171 /*
172  * This macro is used to determine how many extents will be shifted
173  * in one write transaction. We could require two splits,
174  * an extent move on the first and an extent merge on the second,
175  * So it is proper that one extent is shifted inside write transaction
176  * at a time.
177  */
178 #define XFS_BMAP_MAX_SHIFT_EXTENTS	1
179 
180 enum shift_direction {
181 	SHIFT_LEFT = 0,
182 	SHIFT_RIGHT,
183 };
184 
185 #ifdef DEBUG
186 void	xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
187 		int whichfork, unsigned long caller_ip);
188 #define	XFS_BMAP_TRACE_EXLIST(ip,c,w)	\
189 	xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
190 #else
191 #define	XFS_BMAP_TRACE_EXLIST(ip,c,w)
192 #endif
193 
194 int	xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
195 void	xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork);
196 void	xfs_bmap_add_free(struct xfs_mount *mp, struct xfs_bmap_free *flist,
197 			  xfs_fsblock_t bno, xfs_filblks_t len);
198 void	xfs_bmap_cancel(struct xfs_bmap_free *flist);
199 int	xfs_bmap_finish(struct xfs_trans **tp, struct xfs_bmap_free *flist,
200 			struct xfs_inode *ip);
201 void	xfs_bmap_compute_maxlevels(struct xfs_mount *mp, int whichfork);
202 int	xfs_bmap_first_unused(struct xfs_trans *tp, struct xfs_inode *ip,
203 		xfs_extlen_t len, xfs_fileoff_t *unused, int whichfork);
204 int	xfs_bmap_last_before(struct xfs_trans *tp, struct xfs_inode *ip,
205 		xfs_fileoff_t *last_block, int whichfork);
206 int	xfs_bmap_last_offset(struct xfs_inode *ip, xfs_fileoff_t *unused,
207 		int whichfork);
208 int	xfs_bmap_one_block(struct xfs_inode *ip, int whichfork);
209 int	xfs_bmap_read_extents(struct xfs_trans *tp, struct xfs_inode *ip,
210 		int whichfork);
211 int	xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
212 		xfs_filblks_t len, struct xfs_bmbt_irec *mval,
213 		int *nmap, int flags);
214 int	xfs_bmapi_delay(struct xfs_inode *ip, xfs_fileoff_t bno,
215 		xfs_filblks_t len, struct xfs_bmbt_irec *mval,
216 		int *nmap, int flags);
217 int	xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
218 		xfs_fileoff_t bno, xfs_filblks_t len, int flags,
219 		xfs_fsblock_t *firstblock, xfs_extlen_t total,
220 		struct xfs_bmbt_irec *mval, int *nmap,
221 		struct xfs_bmap_free *flist);
222 int	xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
223 		xfs_fileoff_t bno, xfs_filblks_t len, int flags,
224 		xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
225 		struct xfs_bmap_free *flist, int *done);
226 int	xfs_check_nostate_extents(struct xfs_ifork *ifp, xfs_extnum_t idx,
227 		xfs_extnum_t num);
228 uint	xfs_default_attroffset(struct xfs_inode *ip);
229 int	xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
230 		xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
231 		int *done, xfs_fileoff_t stop_fsb, xfs_fsblock_t *firstblock,
232 		struct xfs_bmap_free *flist, enum shift_direction direction,
233 		int num_exts);
234 int	xfs_bmap_split_extent(struct xfs_inode *ip, xfs_fileoff_t split_offset);
235 
236 #endif	/* __XFS_BMAP_H__ */
237