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
 21struct getbmap;
 22struct xfs_bmbt_irec;
 23struct xfs_ifork;
 24struct xfs_inode;
 25struct xfs_mount;
 26struct xfs_trans;
 27
 28extern kmem_zone_t	*xfs_bmap_free_item_zone;
 29
 30/*
 31 * List of extents to be free "later".
 32 * The list is kept sorted on xbf_startblock.
 33 */
 34typedef struct xfs_bmap_free_item
 35{
 36	xfs_fsblock_t		xbfi_startblock;/* starting fs block number */
 37	xfs_extlen_t		xbfi_blockcount;/* number of blocks in extent */
 38	struct xfs_bmap_free_item *xbfi_next;	/* link to next entry */
 39} xfs_bmap_free_item_t;
 40
 41/*
 42 * Header for free extent list.
 43 *
 44 * xbf_low is used by the allocator to activate the lowspace algorithm -
 45 * when free space is running low the extent allocator may choose to
 46 * allocate an extent from an AG without leaving sufficient space for
 47 * a btree split when inserting the new extent.  In this case the allocator
 48 * will enable the lowspace algorithm which is supposed to allow further
 49 * allocations (such as btree splits and newroots) to allocate from
 50 * sequential AGs.  In order to avoid locking AGs out of order the lowspace
 51 * algorithm will start searching for free space from AG 0.  If the correct
 52 * transaction reservations have been made then this algorithm will eventually
 53 * find all the space it needs.
 54 */
 55typedef	struct xfs_bmap_free
 56{
 57	xfs_bmap_free_item_t	*xbf_first;	/* list of to-be-free extents */
 58	int			xbf_count;	/* count of items on list */
 59	int			xbf_low;	/* alloc in low mode */
 60} xfs_bmap_free_t;
 61
 62#define	XFS_BMAP_MAX_NMAP	4
 63
 64/*
 65 * Flags for xfs_bmapi
 66 */
 67#define	XFS_BMAPI_WRITE		0x001	/* write operation: allocate space */
 68#define XFS_BMAPI_DELAY		0x002	/* delayed write operation */
 69#define XFS_BMAPI_ENTIRE	0x004	/* return entire extent, not trimmed */
 70#define XFS_BMAPI_METADATA	0x008	/* mapping metadata not user data */
 71#define XFS_BMAPI_ATTRFORK	0x010	/* use attribute fork not data */
 72#define	XFS_BMAPI_PREALLOC	0x040	/* preallocation op: unwritten space */
 73#define	XFS_BMAPI_IGSTATE	0x080	/* Ignore state - */
 74					/* combine contig. space */
 75#define	XFS_BMAPI_CONTIG	0x100	/* must allocate only one extent */
 76/*
 77 * unwritten extent conversion - this needs write cache flushing and no additional
 78 * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
 79 * from written to unwritten, otherwise convert from unwritten to written.
 80 */
 81#define XFS_BMAPI_CONVERT	0x200
 82
 83#define XFS_BMAPI_FLAGS \
 84	{ XFS_BMAPI_WRITE,	"WRITE" }, \
 85	{ XFS_BMAPI_DELAY,	"DELAY" }, \
 86	{ XFS_BMAPI_ENTIRE,	"ENTIRE" }, \
 87	{ XFS_BMAPI_METADATA,	"METADATA" }, \
 88	{ XFS_BMAPI_ATTRFORK,	"ATTRFORK" }, \
 89	{ XFS_BMAPI_PREALLOC,	"PREALLOC" }, \
 90	{ XFS_BMAPI_IGSTATE,	"IGSTATE" }, \
 91	{ XFS_BMAPI_CONTIG,	"CONTIG" }, \
 92	{ XFS_BMAPI_CONVERT,	"CONVERT" }
 93
 94
 95static inline int xfs_bmapi_aflag(int w)
 96{
 97	return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
 98}
 99
100/*
101 * Special values for xfs_bmbt_irec_t br_startblock field.
102 */
103#define	DELAYSTARTBLOCK		((xfs_fsblock_t)-1LL)
104#define	HOLESTARTBLOCK		((xfs_fsblock_t)-2LL)
105
106static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
107{
108	((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
109		(flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
110}
111
112/*
113 * Argument structure for xfs_bmap_alloc.
114 */
115typedef struct xfs_bmalloca {
116	xfs_fsblock_t		firstblock; /* i/o first block allocated */
117	xfs_fsblock_t		rval;	/* starting block of new extent */
118	xfs_fileoff_t		off;	/* offset in file filling in */
119	struct xfs_trans	*tp;	/* transaction pointer */
120	struct xfs_inode	*ip;	/* incore inode pointer */
121	struct xfs_bmbt_irec	*prevp;	/* extent before the new one */
122	struct xfs_bmbt_irec	*gotp;	/* extent after, or delayed */
123	xfs_extlen_t		alen;	/* i/o length asked/allocated */
124	xfs_extlen_t		total;	/* total blocks needed for xaction */
125	xfs_extlen_t		minlen;	/* minimum allocation size (blocks) */
126	xfs_extlen_t		minleft; /* amount must be left after alloc */
127	char			eof;	/* set if allocating past last extent */
128	char			wasdel;	/* replacing a delayed allocation */
129	char			userdata;/* set if is user data */
130	char			low;	/* low on space, using seq'l ags */
131	char			aeof;	/* allocated space at eof */
132	char			conv;	/* overwriting unwritten extents */
133} xfs_bmalloca_t;
134
135/*
136 * Flags for xfs_bmap_add_extent*.
137 */
138#define BMAP_LEFT_CONTIG	(1 << 0)
139#define BMAP_RIGHT_CONTIG	(1 << 1)
140#define BMAP_LEFT_FILLING	(1 << 2)
141#define BMAP_RIGHT_FILLING	(1 << 3)
142#define BMAP_LEFT_DELAY		(1 << 4)
143#define BMAP_RIGHT_DELAY	(1 << 5)
144#define BMAP_LEFT_VALID		(1 << 6)
145#define BMAP_RIGHT_VALID	(1 << 7)
146#define BMAP_ATTRFORK		(1 << 8)
147
148#define XFS_BMAP_EXT_FLAGS \
149	{ BMAP_LEFT_CONTIG,	"LC" }, \
150	{ BMAP_RIGHT_CONTIG,	"RC" }, \
151	{ BMAP_LEFT_FILLING,	"LF" }, \
152	{ BMAP_RIGHT_FILLING,	"RF" }, \
153	{ BMAP_ATTRFORK,	"ATTR" }
154
155/*
156 * Add bmap trace insert entries for all the contents of the extent list.
157 *
158 * Quite excessive tracing.  Only do this for debug builds.
159 */
160#if defined(__KERNEL) && defined(DEBUG)
161void
162xfs_bmap_trace_exlist(
163	struct xfs_inode	*ip,		/* incore inode pointer */
164	xfs_extnum_t		cnt,		/* count of entries in list */
165	int			whichfork,
166	unsigned long		caller_ip);	/* data or attr fork */
167#define	XFS_BMAP_TRACE_EXLIST(ip,c,w)	\
168	xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
169#else
170#define	XFS_BMAP_TRACE_EXLIST(ip,c,w)
171#endif
172
173/*
174 * Convert inode from non-attributed to attributed.
175 * Must not be in a transaction, ip must not be locked.
176 */
177int					/* error code */
178xfs_bmap_add_attrfork(
179	struct xfs_inode	*ip,	/* incore inode pointer */
180	int			size,	/* space needed for new attribute */
181	int			rsvd);	/* flag for reserved block allocation */
182
183/*
184 * Add the extent to the list of extents to be free at transaction end.
185 * The list is maintained sorted (by block number).
186 */
187void
188xfs_bmap_add_free(
189	xfs_fsblock_t		bno,		/* fs block number of extent */
190	xfs_filblks_t		len,		/* length of extent */
191	xfs_bmap_free_t		*flist,		/* list of extents */
192	struct xfs_mount	*mp);		/* mount point structure */
193
194/*
195 * Routine to clean up the free list data structure when
196 * an error occurs during a transaction.
197 */
198void
199xfs_bmap_cancel(
200	xfs_bmap_free_t		*flist);	/* free list to clean up */
201
202/*
203 * Compute and fill in the value of the maximum depth of a bmap btree
204 * in this filesystem.  Done once, during mount.
205 */
206void
207xfs_bmap_compute_maxlevels(
208	struct xfs_mount	*mp,	/* file system mount structure */
209	int			whichfork);	/* data or attr fork */
210
211/*
212 * Returns the file-relative block number of the first unused block in the file.
213 * This is the lowest-address hole if the file has holes, else the first block
214 * past the end of file.
215 */
216int						/* error */
217xfs_bmap_first_unused(
218	struct xfs_trans	*tp,		/* transaction pointer */
219	struct xfs_inode	*ip,		/* incore inode */
220	xfs_extlen_t		len,		/* size of hole to find */
221	xfs_fileoff_t		*unused,	/* unused block num */
222	int			whichfork);	/* data or attr fork */
223
224/*
225 * Returns the file-relative block number of the last block + 1 before
226 * last_block (input value) in the file.
227 * This is not based on i_size, it is based on the extent list.
228 * Returns 0 for local files, as they do not have an extent list.
229 */
230int						/* error */
231xfs_bmap_last_before(
232	struct xfs_trans	*tp,		/* transaction pointer */
233	struct xfs_inode	*ip,		/* incore inode */
234	xfs_fileoff_t		*last_block,	/* last block */
235	int			whichfork);	/* data or attr fork */
236
237/*
238 * Returns the file-relative block number of the first block past eof in
239 * the file.  This is not based on i_size, it is based on the extent list.
240 * Returns 0 for local files, as they do not have an extent list.
241 */
242int						/* error */
243xfs_bmap_last_offset(
244	struct xfs_trans	*tp,		/* transaction pointer */
245	struct xfs_inode	*ip,		/* incore inode */
246	xfs_fileoff_t		*unused,	/* last block num */
247	int			whichfork);	/* data or attr fork */
248
249/*
250 * Returns whether the selected fork of the inode has exactly one
251 * block or not.  For the data fork we check this matches di_size,
252 * implying the file's range is 0..bsize-1.
253 */
254int
255xfs_bmap_one_block(
256	struct xfs_inode	*ip,		/* incore inode */
257	int			whichfork);	/* data or attr fork */
258
259/*
260 * Read in the extents to iu_extents.
261 * All inode fields are set up by caller, we just traverse the btree
262 * and copy the records in.
263 */
264int						/* error */
265xfs_bmap_read_extents(
266	struct xfs_trans	*tp,		/* transaction pointer */
267	struct xfs_inode	*ip,		/* incore inode */
268	int			whichfork);	/* data or attr fork */
269
270/*
271 * Map file blocks to filesystem blocks.
272 * File range is given by the bno/len pair.
273 * Adds blocks to file if a write ("flags & XFS_BMAPI_WRITE" set)
274 * into a hole or past eof.
275 * Only allocates blocks from a single allocation group,
276 * to avoid locking problems.
277 * The returned value in "firstblock" from the first call in a transaction
278 * must be remembered and presented to subsequent calls in "firstblock".
279 * An upper bound for the number of blocks to be allocated is supplied to
280 * the first call in "total"; if no allocation group has that many free
281 * blocks then the call will fail (return NULLFSBLOCK in "firstblock").
282 */
283int						/* error */
284xfs_bmapi(
285	struct xfs_trans	*tp,		/* transaction pointer */
286	struct xfs_inode	*ip,		/* incore inode */
287	xfs_fileoff_t		bno,		/* starting file offs. mapped */
288	xfs_filblks_t		len,		/* length to map in file */
289	int			flags,		/* XFS_BMAPI_... */
290	xfs_fsblock_t		*firstblock,	/* first allocated block
291						   controls a.g. for allocs */
292	xfs_extlen_t		total,		/* total blocks needed */
293	struct xfs_bmbt_irec	*mval,		/* output: map values */
294	int			*nmap,		/* i/o: mval size/count */
295	xfs_bmap_free_t		*flist);	/* i/o: list extents to free */
296
297/*
298 * Map file blocks to filesystem blocks, simple version.
299 * One block only, read-only.
300 * For flags, only the XFS_BMAPI_ATTRFORK flag is examined.
301 * For the other flag values, the effect is as if XFS_BMAPI_METADATA
302 * was set and all the others were clear.
303 */
304int						/* error */
305xfs_bmapi_single(
306	struct xfs_trans	*tp,		/* transaction pointer */
307	struct xfs_inode	*ip,		/* incore inode */
308	int			whichfork,	/* data or attr fork */
309	xfs_fsblock_t		*fsb,		/* output: mapped block */
310	xfs_fileoff_t		bno);		/* starting file offs. mapped */
311
312/*
313 * Unmap (remove) blocks from a file.
314 * If nexts is nonzero then the number of extents to remove is limited to
315 * that value.  If not all extents in the block range can be removed then
316 * *done is set.
317 */
318int						/* error */
319xfs_bunmapi(
320	struct xfs_trans	*tp,		/* transaction pointer */
321	struct xfs_inode	*ip,		/* incore inode */
322	xfs_fileoff_t		bno,		/* starting offset to unmap */
323	xfs_filblks_t		len,		/* length to unmap in file */
324	int			flags,		/* XFS_BMAPI_... */
325	xfs_extnum_t		nexts,		/* number of extents max */
326	xfs_fsblock_t		*firstblock,	/* first allocated block
327						   controls a.g. for allocs */
328	xfs_bmap_free_t		*flist,		/* i/o: list extents to free */
329	int			*done);		/* set if not done yet */
330
331/*
332 * Check an extent list, which has just been read, for
333 * any bit in the extent flag field.
334 */
335int
336xfs_check_nostate_extents(
337	struct xfs_ifork	*ifp,
338	xfs_extnum_t		idx,
339	xfs_extnum_t		num);
340
341uint
342xfs_default_attroffset(
343	struct xfs_inode	*ip);
344
345#ifdef __KERNEL__
346
347/*
348 * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi
349 * caller.  Frees all the extents that need freeing, which must be done
350 * last due to locking considerations.
351 *
352 * Return 1 if the given transaction was committed and a new one allocated,
353 * and 0 otherwise.
354 */
355int						/* error */
356xfs_bmap_finish(
357	struct xfs_trans	**tp,		/* transaction pointer addr */
358	xfs_bmap_free_t		*flist,		/* i/o: list extents to free */
359	int			*committed);	/* xact committed or not */
360
361/* bmap to userspace formatter - copy to user & advance pointer */
362typedef int (*xfs_bmap_format_t)(void **, struct getbmapx *, int *);
363
364/*
365 * Get inode's extents as described in bmv, and format for output.
366 */
367int						/* error code */
368xfs_getbmap(
369	xfs_inode_t		*ip,
370	struct getbmapx		*bmv,		/* user bmap structure */
371	xfs_bmap_format_t	formatter,	/* format to user */
372	void			*arg);		/* formatter arg */
373
374/*
375 * Check if the endoff is outside the last extent. If so the caller will grow
376 * the allocation to a stripe unit boundary
377 */
378int
379xfs_bmap_eof(
380	struct xfs_inode        *ip,
381	xfs_fileoff_t           endoff,
382	int                     whichfork,
383	int                     *eof);
384
385/*
386 * Count fsblocks of the given fork.
387 */
388int
389xfs_bmap_count_blocks(
390	xfs_trans_t		*tp,
391	struct xfs_inode	*ip,
392	int			whichfork,
393	int			*count);
394
395int
396xfs_bmap_punch_delalloc_range(
397	struct xfs_inode	*ip,
398	xfs_fileoff_t		start_fsb,
399	xfs_fileoff_t		length);
400#endif	/* __KERNEL__ */
401
402#endif	/* __XFS_BMAP_H__ */