aboutsummaryrefslogtreecommitdiffstats
path: root/fs/xfs/xfs_attr_leaf.h
diff options
context:
space:
mode:
Diffstat (limited to 'fs/xfs/xfs_attr_leaf.h')
-rw-r--r--fs/xfs/xfs_attr_leaf.h308
1 files changed, 308 insertions, 0 deletions
diff --git a/fs/xfs/xfs_attr_leaf.h b/fs/xfs/xfs_attr_leaf.h
new file mode 100644
index 000000000000..b1480e0b3349
--- /dev/null
+++ b/fs/xfs/xfs_attr_leaf.h
@@ -0,0 +1,308 @@
1/*
2 * Copyright (c) 2000, 2002-2003 Silicon Graphics, Inc. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11 *
12 * Further, this software is distributed without any warranty that it is
13 * free of the rightful claim of any third person regarding infringement
14 * or the like. Any license provided herein, whether implied or
15 * otherwise, applies only to this software file. Patent licenses, if
16 * any, provided herein do not apply to combinations of this program with
17 * other software, or any other product whatsoever.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write the Free Software Foundation, Inc., 59
21 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22 *
23 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24 * Mountain View, CA 94043, or:
25 *
26 * http://www.sgi.com
27 *
28 * For further information regarding this notice, see:
29 *
30 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31 */
32#ifndef __XFS_ATTR_LEAF_H__
33#define __XFS_ATTR_LEAF_H__
34
35/*
36 * Attribute storage layout, internal structure, access macros, etc.
37 *
38 * Attribute lists are structured around Btrees where all the data
39 * elements are in the leaf nodes. Attribute names are hashed into an int,
40 * then that int is used as the index into the Btree. Since the hashval
41 * of an attribute name may not be unique, we may have duplicate keys. The
42 * internal links in the Btree are logical block offsets into the file.
43 */
44
45struct attrlist;
46struct attrlist_cursor_kern;
47struct attrnames;
48struct xfs_dabuf;
49struct xfs_da_args;
50struct xfs_da_state;
51struct xfs_da_state_blk;
52struct xfs_inode;
53struct xfs_trans;
54
55/*========================================================================
56 * Attribute structure when equal to XFS_LBSIZE(mp) bytes.
57 *========================================================================*/
58
59/*
60 * This is the structure of the leaf nodes in the Btree.
61 *
62 * Struct leaf_entry's are packed from the top. Name/values grow from the
63 * bottom but are not packed. The freemap contains run-length-encoded entries
64 * for the free bytes after the leaf_entry's, but only the N largest such,
65 * smaller runs are dropped. When the freemap doesn't show enough space
66 * for an allocation, we compact the name/value area and try again. If we
67 * still don't have enough space, then we have to split the block. The
68 * name/value structs (both local and remote versions) must be 32bit aligned.
69 *
70 * Since we have duplicate hash keys, for each key that matches, compare
71 * the actual name string. The root and intermediate node search always
72 * takes the first-in-the-block key match found, so we should only have
73 * to work "forw"ard. If none matches, continue with the "forw"ard leaf
74 * nodes until the hash key changes or the attribute name is found.
75 *
76 * We store the fact that an attribute is a ROOT/USER/SECURE attribute in
77 * the leaf_entry. The namespaces are independent only because we also look
78 * at the namespace bit when we are looking for a matching attribute name.
79 *
80 * We also store a "incomplete" bit in the leaf_entry. It shows that an
81 * attribute is in the middle of being created and should not be shown to
82 * the user if we crash during the time that the bit is set. We clear the
83 * bit when we have finished setting up the attribute. We do this because
84 * we cannot create some large attributes inside a single transaction, and we
85 * need some indication that we weren't finished if we crash in the middle.
86 */
87#define XFS_ATTR_LEAF_MAPSIZE 3 /* how many freespace slots */
88
89typedef struct xfs_attr_leafblock {
90 struct xfs_attr_leaf_hdr { /* constant-structure header block */
91 xfs_da_blkinfo_t info; /* block type, links, etc. */
92 __uint16_t count; /* count of active leaf_entry's */
93 __uint16_t usedbytes; /* num bytes of names/values stored */
94 __uint16_t firstused; /* first used byte in name area */
95 __uint8_t holes; /* != 0 if blk needs compaction */
96 __uint8_t pad1;
97 struct xfs_attr_leaf_map { /* RLE map of free bytes */
98 __uint16_t base; /* base of free region */
99 __uint16_t size; /* length of free region */
100 } freemap[XFS_ATTR_LEAF_MAPSIZE]; /* N largest free regions */
101 } hdr;
102 struct xfs_attr_leaf_entry { /* sorted on key, not name */
103 xfs_dahash_t hashval; /* hash value of name */
104 __uint16_t nameidx; /* index into buffer of name/value */
105 __uint8_t flags; /* LOCAL/ROOT/SECURE/INCOMPLETE flag */
106 __uint8_t pad2; /* unused pad byte */
107 } entries[1]; /* variable sized array */
108 struct xfs_attr_leaf_name_local {
109 __uint16_t valuelen; /* number of bytes in value */
110 __uint8_t namelen; /* length of name bytes */
111 __uint8_t nameval[1]; /* name/value bytes */
112 } namelist; /* grows from bottom of buf */
113 struct xfs_attr_leaf_name_remote {
114 xfs_dablk_t valueblk; /* block number of value bytes */
115 __uint32_t valuelen; /* number of bytes in value */
116 __uint8_t namelen; /* length of name bytes */
117 __uint8_t name[1]; /* name bytes */
118 } valuelist; /* grows from bottom of buf */
119} xfs_attr_leafblock_t;
120typedef struct xfs_attr_leaf_hdr xfs_attr_leaf_hdr_t;
121typedef struct xfs_attr_leaf_map xfs_attr_leaf_map_t;
122typedef struct xfs_attr_leaf_entry xfs_attr_leaf_entry_t;
123typedef struct xfs_attr_leaf_name_local xfs_attr_leaf_name_local_t;
124typedef struct xfs_attr_leaf_name_remote xfs_attr_leaf_name_remote_t;
125
126/*
127 * Flags used in the leaf_entry[i].flags field.
128 * NOTE: the INCOMPLETE bit must not collide with the flags bits specified
129 * on the system call, they are "or"ed together for various operations.
130 */
131#define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */
132#define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */
133#define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */
134#define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */
135#define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT)
136#define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT)
137#define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT)
138#define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT)
139
140/*
141 * Alignment for namelist and valuelist entries (since they are mixed
142 * there can be only one alignment value)
143 */
144#define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t))
145
146/*
147 * Cast typed pointers for "local" and "remote" name/value structs.
148 */
149#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME_REMOTE)
150xfs_attr_leaf_name_remote_t *
151xfs_attr_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx);
152#define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) \
153 xfs_attr_leaf_name_remote(leafp,idx)
154#else
155#define XFS_ATTR_LEAF_NAME_REMOTE(leafp,idx) /* remote name struct ptr */ \
156 ((xfs_attr_leaf_name_remote_t *) \
157 &((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ])
158#endif
159#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME_LOCAL)
160xfs_attr_leaf_name_local_t *
161xfs_attr_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx);
162#define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) \
163 xfs_attr_leaf_name_local(leafp,idx)
164#else
165#define XFS_ATTR_LEAF_NAME_LOCAL(leafp,idx) /* local name struct ptr */ \
166 ((xfs_attr_leaf_name_local_t *) \
167 &((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ])
168#endif
169#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_NAME)
170char *xfs_attr_leaf_name(xfs_attr_leafblock_t *leafp, int idx);
171#define XFS_ATTR_LEAF_NAME(leafp,idx) xfs_attr_leaf_name(leafp,idx)
172#else
173#define XFS_ATTR_LEAF_NAME(leafp,idx) /* generic name struct ptr */ \
174 (&((char *)(leafp))[ INT_GET((leafp)->entries[idx].nameidx, ARCH_CONVERT) ])
175#endif
176
177/*
178 * Calculate total bytes used (including trailing pad for alignment) for
179 * a "local" name/value structure, a "remote" name/value structure, and
180 * a pointer which might be either.
181 */
182#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_REMOTE)
183int xfs_attr_leaf_entsize_remote(int nlen);
184#define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) \
185 xfs_attr_leaf_entsize_remote(nlen)
186#else
187#define XFS_ATTR_LEAF_ENTSIZE_REMOTE(nlen) /* space for remote struct */ \
188 (((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \
189 XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1))
190#endif
191#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_LOCAL)
192int xfs_attr_leaf_entsize_local(int nlen, int vlen);
193#define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) \
194 xfs_attr_leaf_entsize_local(nlen,vlen)
195#else
196#define XFS_ATTR_LEAF_ENTSIZE_LOCAL(nlen,vlen) /* space for local struct */ \
197 (((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) + \
198 XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1))
199#endif
200#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX)
201int xfs_attr_leaf_entsize_local_max(int bsize);
202#define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) \
203 xfs_attr_leaf_entsize_local_max(bsize)
204#else
205#define XFS_ATTR_LEAF_ENTSIZE_LOCAL_MAX(bsize) /* max local struct size */ \
206 (((bsize) >> 1) + ((bsize) >> 2))
207#endif
208
209
210/*========================================================================
211 * Structure used to pass context around among the routines.
212 *========================================================================*/
213
214typedef struct xfs_attr_list_context {
215 struct xfs_inode *dp; /* inode */
216 struct attrlist_cursor_kern *cursor;/* position in list */
217 struct attrlist *alist; /* output buffer */
218 int count; /* num used entries */
219 int dupcnt; /* count dup hashvals seen */
220 int bufsize;/* total buffer size */
221 int firstu; /* first used byte in buffer */
222 int flags; /* from VOP call */
223 int resynch;/* T/F: resynch with cursor */
224} xfs_attr_list_context_t;
225
226/*
227 * Used to keep a list of "remote value" extents when unlinking an inode.
228 */
229typedef struct xfs_attr_inactive_list {
230 xfs_dablk_t valueblk; /* block number of value bytes */
231 int valuelen; /* number of bytes in value */
232} xfs_attr_inactive_list_t;
233
234
235/*========================================================================
236 * Function prototypes for the kernel.
237 *========================================================================*/
238
239/*
240 * Internal routines when dirsize < XFS_LITINO(mp).
241 */
242int xfs_attr_shortform_create(struct xfs_da_args *args);
243int xfs_attr_shortform_add(struct xfs_da_args *add);
244int xfs_attr_shortform_lookup(struct xfs_da_args *args);
245int xfs_attr_shortform_getvalue(struct xfs_da_args *args);
246int xfs_attr_shortform_to_leaf(struct xfs_da_args *args);
247int xfs_attr_shortform_remove(struct xfs_da_args *remove);
248int xfs_attr_shortform_list(struct xfs_attr_list_context *context);
249int xfs_attr_shortform_allfit(struct xfs_dabuf *bp, struct xfs_inode *dp);
250
251/*
252 * Internal routines when dirsize == XFS_LBSIZE(mp).
253 */
254int xfs_attr_leaf_to_node(struct xfs_da_args *args);
255int xfs_attr_leaf_to_shortform(struct xfs_dabuf *bp,
256 struct xfs_da_args *args);
257int xfs_attr_leaf_clearflag(struct xfs_da_args *args);
258int xfs_attr_leaf_setflag(struct xfs_da_args *args);
259int xfs_attr_leaf_flipflags(xfs_da_args_t *args);
260
261/*
262 * Routines used for growing the Btree.
263 */
264int xfs_attr_leaf_create(struct xfs_da_args *args, xfs_dablk_t which_block,
265 struct xfs_dabuf **bpp);
266int xfs_attr_leaf_split(struct xfs_da_state *state,
267 struct xfs_da_state_blk *oldblk,
268 struct xfs_da_state_blk *newblk);
269int xfs_attr_leaf_lookup_int(struct xfs_dabuf *leaf,
270 struct xfs_da_args *args);
271int xfs_attr_leaf_getvalue(struct xfs_dabuf *bp, struct xfs_da_args *args);
272int xfs_attr_leaf_add(struct xfs_dabuf *leaf_buffer,
273 struct xfs_da_args *args);
274int xfs_attr_leaf_remove(struct xfs_dabuf *leaf_buffer,
275 struct xfs_da_args *args);
276int xfs_attr_leaf_list_int(struct xfs_dabuf *bp,
277 struct xfs_attr_list_context *context);
278
279/*
280 * Routines used for shrinking the Btree.
281 */
282int xfs_attr_leaf_toosmall(struct xfs_da_state *state, int *retval);
283void xfs_attr_leaf_unbalance(struct xfs_da_state *state,
284 struct xfs_da_state_blk *drop_blk,
285 struct xfs_da_state_blk *save_blk);
286int xfs_attr_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp);
287int xfs_attr_node_inactive(struct xfs_trans **trans, struct xfs_inode *dp,
288 struct xfs_dabuf *bp, int level);
289int xfs_attr_leaf_inactive(struct xfs_trans **trans, struct xfs_inode *dp,
290 struct xfs_dabuf *bp);
291int xfs_attr_leaf_freextent(struct xfs_trans **trans, struct xfs_inode *dp,
292 xfs_dablk_t blkno, int blkcnt);
293
294/*
295 * Utility routines.
296 */
297xfs_dahash_t xfs_attr_leaf_lasthash(struct xfs_dabuf *bp, int *count);
298int xfs_attr_leaf_order(struct xfs_dabuf *leaf1_bp,
299 struct xfs_dabuf *leaf2_bp);
300int xfs_attr_leaf_newentsize(struct xfs_da_args *args, int blocksize,
301 int *local);
302int xfs_attr_leaf_entsize(struct xfs_attr_leafblock *leaf, int index);
303int xfs_attr_put_listent(struct xfs_attr_list_context *context,
304 struct attrnames *, char *name, int namelen,
305 int valuelen);
306int xfs_attr_rolltrans(struct xfs_trans **transp, struct xfs_inode *dp);
307
308#endif /* __XFS_ATTR_LEAF_H__ */
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-19 08:20:05 -0500