xfs_da_btree.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
  4 * Copyright (c) 2013 Red Hat, Inc.
  5 * All Rights Reserved.
  6 */
  7#ifndef __XFS_DA_BTREE_H__
  8#define	__XFS_DA_BTREE_H__
  9
 10struct xfs_inode;
 11struct xfs_trans;
 12
 13/*
 14 * Directory/attribute geometry information. There will be one of these for each
 15 * data fork type, and it will be passed around via the xfs_da_args. Global
 16 * structures will be attached to the xfs_mount.
 17 */
 18struct xfs_da_geometry {
 19	unsigned int	blksize;	/* da block size in bytes */
 20	unsigned int	fsbcount;	/* da block size in filesystem blocks */
 21	uint8_t		fsblog;		/* log2 of _filesystem_ block size */
 22	uint8_t		blklog;		/* log2 of da block size */
 23	unsigned int	node_hdr_size;	/* danode header size in bytes */
 24	unsigned int	node_ents;	/* # of entries in a danode */
 25	unsigned int	magicpct;	/* 37% of block size in bytes */
 26	xfs_dablk_t	datablk;	/* blockno of dir data v2 */
 27	unsigned int	leaf_hdr_size;	/* dir2 leaf header size */
 28	unsigned int	leaf_max_ents;	/* # of entries in dir2 leaf */
 29	xfs_dablk_t	leafblk;	/* blockno of leaf data v2 */
 30	unsigned int	free_hdr_size;	/* dir2 free header size */
 31	unsigned int	free_max_bests;	/* # of bests entries in dir2 free */
 32	xfs_dablk_t	freeblk;	/* blockno of free data v2 */
 33	xfs_extnum_t	max_extents;	/* Max. extents in corresponding fork */
 34
 35	xfs_dir2_data_aoff_t data_first_offset;
 36	size_t		data_entry_offset;
 37};
 38
 39/*========================================================================
 40 * Btree searching and modification structure definitions.
 41 *========================================================================*/
 42
 43/*
 44 * Search comparison results
 45 */
 46enum xfs_dacmp {
 47	XFS_CMP_DIFFERENT,	/* names are completely different */
 48	XFS_CMP_EXACT,		/* names are exactly the same */
 49	XFS_CMP_CASE		/* names are same but differ in case */
 50};
 51
 52/*
 53 * Structure to ease passing around component names.
 54 */
 55typedef struct xfs_da_args {
 56	struct xfs_da_geometry *geo;	/* da block geometry */
 57	const uint8_t	*name;		/* string (maybe not NULL terminated) */
 58	const uint8_t	*new_name;	/* new attr name */
 59	void		*value;		/* set of bytes (maybe contain NULLs) */
 60	void		*new_value;	/* new xattr value (may contain NULLs) */
 61	struct xfs_inode *dp;		/* directory inode to manipulate */
 62	struct xfs_trans *trans;	/* current trans (changes over time) */
 63
 64	xfs_ino_t	inumber;	/* input/output inode number */
 65	xfs_ino_t	owner;		/* inode that owns the dir/attr data */
 66
 67	int		valuelen;	/* length of value */
 68	int		new_valuelen;	/* length of new_value */
 69	uint8_t		filetype;	/* filetype of inode for directories */
 70	uint8_t		op_flags;	/* operation flags */
 71	uint8_t		attr_filter;	/* XFS_ATTR_{ROOT,SECURE,INCOMPLETE} */
 72	short		namelen;	/* length of string (maybe no NULL) */
 73	short		new_namelen;	/* length of new attr name */
 74	xfs_dahash_t	hashval;	/* hash value of name */
 75	xfs_extlen_t	total;		/* total blocks needed, for 1st bmap */
 76	int		whichfork;	/* data or attribute fork */
 77	xfs_dablk_t	blkno;		/* blkno of attr leaf of interest */
 78	int		index;		/* index of attr of interest in blk */
 79	xfs_dablk_t	rmtblkno;	/* remote attr value starting blkno */
 80	int		rmtblkcnt;	/* remote attr value block count */
 81	int		rmtvaluelen;	/* remote attr value length in bytes */
 82	xfs_dablk_t	blkno2;		/* blkno of 2nd attr leaf of interest */
 83	int		index2;		/* index of 2nd attr in blk */
 84	xfs_dablk_t	rmtblkno2;	/* remote attr value starting blkno */
 85	int		rmtblkcnt2;	/* remote attr value block count */
 86	int		rmtvaluelen2;	/* remote attr value length in bytes */
 87	enum xfs_dacmp	cmpresult;	/* name compare result for lookups */
 88} xfs_da_args_t;
 89
 90/*
 91 * Operation flags:
 92 */
 93#define XFS_DA_OP_JUSTCHECK	(1u << 0) /* check for ok with no space */
 94#define XFS_DA_OP_REPLACE	(1u << 1) /* this is an atomic replace op */
 95#define XFS_DA_OP_ADDNAME	(1u << 2) /* this is an add operation */
 96#define XFS_DA_OP_OKNOENT	(1u << 3) /* lookup op, ENOENT ok, else die */
 97#define XFS_DA_OP_CILOOKUP	(1u << 4) /* lookup returns CI name if found */
 98#define XFS_DA_OP_RECOVERY	(1u << 5) /* Log recovery operation */
 99#define XFS_DA_OP_LOGGED	(1u << 6) /* Use intent items to track op */
100
101#define XFS_DA_OP_FLAGS \
102	{ XFS_DA_OP_JUSTCHECK,	"JUSTCHECK" }, \
103	{ XFS_DA_OP_REPLACE,	"REPLACE" }, \
104	{ XFS_DA_OP_ADDNAME,	"ADDNAME" }, \
105	{ XFS_DA_OP_OKNOENT,	"OKNOENT" }, \
106	{ XFS_DA_OP_CILOOKUP,	"CILOOKUP" }, \
107	{ XFS_DA_OP_RECOVERY,	"RECOVERY" }, \
108	{ XFS_DA_OP_LOGGED,	"LOGGED" }
109
110/*
111 * Storage for holding state during Btree searches and split/join ops.
112 *
113 * Only need space for 5 intermediate nodes.  With a minimum of 62-way
114 * fanout to the Btree, we can support over 900 million directory blocks,
115 * which is slightly more than enough.
116 */
117typedef struct xfs_da_state_blk {
118	struct xfs_buf	*bp;		/* buffer containing block */
119	xfs_dablk_t	blkno;		/* filesystem blkno of buffer */
120	xfs_daddr_t	disk_blkno;	/* on-disk blkno (in BBs) of buffer */
121	int		index;		/* relevant index into block */
122	xfs_dahash_t	hashval;	/* last hash value in block */
123	int		magic;		/* blk's magic number, ie: blk type */
124} xfs_da_state_blk_t;
125
126typedef struct xfs_da_state_path {
127	int			active;		/* number of active levels */
128	xfs_da_state_blk_t	blk[XFS_DA_NODE_MAXDEPTH];
129} xfs_da_state_path_t;
130
131typedef struct xfs_da_state {
132	xfs_da_args_t		*args;		/* filename arguments */
133	struct xfs_mount	*mp;		/* filesystem mount point */
134	xfs_da_state_path_t	path;		/* search/split paths */
135	xfs_da_state_path_t	altpath;	/* alternate path for join */
136	unsigned char		inleaf;		/* insert into 1->lf, 0->splf */
137	unsigned char		extravalid;	/* T/F: extrablk is in use */
138	unsigned char		extraafter;	/* T/F: extrablk is after new */
139	xfs_da_state_blk_t	extrablk;	/* for double-splits on leaves */
140						/* for dirv2 extrablk is data */
141} xfs_da_state_t;
142
143/*
144 * In-core version of the node header to abstract the differences in the v2 and
145 * v3 disk format of the headers. Callers need to convert to/from disk format as
146 * appropriate.
147 */
148struct xfs_da3_icnode_hdr {
149	uint32_t		forw;
150	uint32_t		back;
151	uint16_t		magic;
152	uint16_t		count;
153	uint16_t		level;
154
155	/*
156	 * Pointer to the on-disk format entries, which are behind the
157	 * variable size (v4 vs v5) header in the on-disk block.
158	 */
159	struct xfs_da_node_entry *btree;
160};
161
162/*
163 * Utility macros to aid in logging changed structure fields.
164 */
165#define XFS_DA_LOGOFF(BASE, ADDR)	((char *)(ADDR) - (char *)(BASE))
166#define XFS_DA_LOGRANGE(BASE, ADDR, SIZE)	\
167		(uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
168		(uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
169
170/*========================================================================
171 * Function prototypes.
172 *========================================================================*/
173
174/*
175 * Routines used for growing the Btree.
176 */
177int	xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno,
178			    int level, struct xfs_buf **bpp, int whichfork);
179int	xfs_da3_split(xfs_da_state_t *state);
180
181/*
182 * Routines used for shrinking the Btree.
183 */
184int	xfs_da3_join(xfs_da_state_t *state);
185void	xfs_da3_fixhashpath(struct xfs_da_state *state,
186			    struct xfs_da_state_path *path_to_to_fix);
187void	xfs_attr3_node_entry_remove(struct xfs_trans *tp, struct xfs_inode *dp,
188			    struct xfs_buf *bp, int index);
189
190/*
191 * Routines used for finding things in the Btree.
192 */
193int	xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result);
194int	xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
195					 int forward, int release, int *result);
196/*
197 * Utility routines.
198 */
199int	xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
200				       xfs_da_state_blk_t *new_blk);
201int	xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp,
202			xfs_dablk_t bno, struct xfs_buf **bpp, int whichfork);
203int	xfs_da3_node_read_mapped(struct xfs_trans *tp, struct xfs_inode *dp,
204			xfs_daddr_t mappedbno, struct xfs_buf **bpp,
205			int whichfork);
206
207/*
208 * Utility routines.
209 */
210
211#define XFS_DABUF_MAP_HOLE_OK	(1u << 0)
212
213int	xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
214int	xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
215			      int count);
216int	xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
217		xfs_dablk_t bno, struct xfs_buf **bp, int whichfork);
218int	xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
219		xfs_dablk_t bno, unsigned int flags, struct xfs_buf **bpp,
220		int whichfork, const struct xfs_buf_ops *ops);
221int	xfs_da_reada_buf(struct xfs_inode *dp, xfs_dablk_t bno,
222		unsigned int flags, int whichfork,
223		const struct xfs_buf_ops *ops);
224int	xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
225					  struct xfs_buf *dead_buf);
226void	xfs_da_buf_copy(struct xfs_buf *dst, struct xfs_buf *src,
227			size_t size);
228
229uint xfs_da_hashname(const uint8_t *name_string, int name_length);
230enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
231				const unsigned char *name, int len);
232
233
234struct xfs_da_state *xfs_da_state_alloc(struct xfs_da_args *args);
235void xfs_da_state_free(xfs_da_state_t *state);
236void xfs_da_state_reset(struct xfs_da_state *state, struct xfs_da_args *args);
237
238void	xfs_da3_node_hdr_from_disk(struct xfs_mount *mp,
239		struct xfs_da3_icnode_hdr *to, struct xfs_da_intnode *from);
240void	xfs_da3_node_hdr_to_disk(struct xfs_mount *mp,
241		struct xfs_da_intnode *to, struct xfs_da3_icnode_hdr *from);
242xfs_failaddr_t xfs_da3_header_check(struct xfs_buf *bp, xfs_ino_t owner);
243xfs_failaddr_t xfs_da3_node_header_check(struct xfs_buf *bp, xfs_ino_t owner);
244
245extern struct kmem_cache	*xfs_da_state_cache;
246
247#endif	/* __XFS_DA_BTREE_H__ */