disable some mediatekl custom warnings
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / xfs / xfs_attr_leaf.h
CommitLineData
1da177e4 1/*
7b718769 2 * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc.
517c2220 3 * Copyright (c) 2013 Red Hat, Inc.
aa82daa0 4 * All Rights Reserved.
1da177e4 5 *
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6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
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8 * published by the Free Software Foundation.
9 *
7b718769
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10 * This program is distributed in the hope that it would be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
1da177e4 14 *
7b718769
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15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
1da177e4
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18 */
19#ifndef __XFS_ATTR_LEAF_H__
20#define __XFS_ATTR_LEAF_H__
21
22/*
23 * Attribute storage layout, internal structure, access macros, etc.
24 *
25 * Attribute lists are structured around Btrees where all the data
26 * elements are in the leaf nodes. Attribute names are hashed into an int,
27 * then that int is used as the index into the Btree. Since the hashval
28 * of an attribute name may not be unique, we may have duplicate keys. The
29 * internal links in the Btree are logical block offsets into the file.
30 */
31
32struct attrlist;
33struct attrlist_cursor_kern;
ad9b463a 34struct xfs_attr_list_context;
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35struct xfs_da_args;
36struct xfs_da_state;
37struct xfs_da_state_blk;
38struct xfs_inode;
39struct xfs_trans;
40
41/*========================================================================
42 * Attribute structure when equal to XFS_LBSIZE(mp) bytes.
43 *========================================================================*/
44
45/*
46 * This is the structure of the leaf nodes in the Btree.
47 *
48 * Struct leaf_entry's are packed from the top. Name/values grow from the
49 * bottom but are not packed. The freemap contains run-length-encoded entries
50 * for the free bytes after the leaf_entry's, but only the N largest such,
51 * smaller runs are dropped. When the freemap doesn't show enough space
52 * for an allocation, we compact the name/value area and try again. If we
53 * still don't have enough space, then we have to split the block. The
54 * name/value structs (both local and remote versions) must be 32bit aligned.
55 *
56 * Since we have duplicate hash keys, for each key that matches, compare
57 * the actual name string. The root and intermediate node search always
58 * takes the first-in-the-block key match found, so we should only have
59 * to work "forw"ard. If none matches, continue with the "forw"ard leaf
60 * nodes until the hash key changes or the attribute name is found.
61 *
62 * We store the fact that an attribute is a ROOT/USER/SECURE attribute in
63 * the leaf_entry. The namespaces are independent only because we also look
64 * at the namespace bit when we are looking for a matching attribute name.
65 *
3762ec6b 66 * We also store an "incomplete" bit in the leaf_entry. It shows that an
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67 * attribute is in the middle of being created and should not be shown to
68 * the user if we crash during the time that the bit is set. We clear the
69 * bit when we have finished setting up the attribute. We do this because
70 * we cannot create some large attributes inside a single transaction, and we
71 * need some indication that we weren't finished if we crash in the middle.
72 */
73#define XFS_ATTR_LEAF_MAPSIZE 3 /* how many freespace slots */
74
3762ec6b 75typedef struct xfs_attr_leaf_map { /* RLE map of free bytes */
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76 __be16 base; /* base of free region */
77 __be16 size; /* length of free region */
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78} xfs_attr_leaf_map_t;
79
80typedef struct xfs_attr_leaf_hdr { /* constant-structure header block */
81 xfs_da_blkinfo_t info; /* block type, links, etc. */
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82 __be16 count; /* count of active leaf_entry's */
83 __be16 usedbytes; /* num bytes of names/values stored */
84 __be16 firstused; /* first used byte in name area */
85 __u8 holes; /* != 0 if blk needs compaction */
86 __u8 pad1;
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87 xfs_attr_leaf_map_t freemap[XFS_ATTR_LEAF_MAPSIZE];
88 /* N largest free regions */
89} xfs_attr_leaf_hdr_t;
90
91typedef struct xfs_attr_leaf_entry { /* sorted on key, not name */
6b19f2d8 92 __be32 hashval; /* hash value of name */
517c2220 93 __be16 nameidx; /* index into buffer of name/value */
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94 __u8 flags; /* LOCAL/ROOT/SECURE/INCOMPLETE flag */
95 __u8 pad2; /* unused pad byte */
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96} xfs_attr_leaf_entry_t;
97
98typedef struct xfs_attr_leaf_name_local {
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99 __be16 valuelen; /* number of bytes in value */
100 __u8 namelen; /* length of name bytes */
101 __u8 nameval[1]; /* name/value bytes */
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102} xfs_attr_leaf_name_local_t;
103
104typedef struct xfs_attr_leaf_name_remote {
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105 __be32 valueblk; /* block number of value bytes */
106 __be32 valuelen; /* number of bytes in value */
107 __u8 namelen; /* length of name bytes */
108 __u8 name[1]; /* name bytes */
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109} xfs_attr_leaf_name_remote_t;
110
1da177e4 111typedef struct xfs_attr_leafblock {
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112 xfs_attr_leaf_hdr_t hdr; /* constant-structure header block */
113 xfs_attr_leaf_entry_t entries[1]; /* sorted on key, not name */
114 xfs_attr_leaf_name_local_t namelist; /* grows from bottom of buf */
115 xfs_attr_leaf_name_remote_t valuelist; /* grows from bottom of buf */
1da177e4 116} xfs_attr_leafblock_t;
1da177e4 117
517c2220
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118/*
119 * CRC enabled leaf structures. Called "version 3" structures to match the
120 * version number of the directory and dablk structures for this feature, and
121 * attr2 is already taken by the variable inode attribute fork size feature.
122 */
123struct xfs_attr3_leaf_hdr {
124 struct xfs_da3_blkinfo info;
125 __be16 count;
126 __be16 usedbytes;
127 __be16 firstused;
128 __u8 holes;
129 __u8 pad1;
130 struct xfs_attr_leaf_map freemap[XFS_ATTR_LEAF_MAPSIZE];
5170711d 131 __be32 pad2; /* 64 bit alignment */
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DC
132};
133
134#define XFS_ATTR3_LEAF_CRC_OFF (offsetof(struct xfs_attr3_leaf_hdr, info.crc))
135
136struct xfs_attr3_leafblock {
137 struct xfs_attr3_leaf_hdr hdr;
138 struct xfs_attr_leaf_entry entries[1];
139
140 /*
141 * The rest of the block contains the following structures after the
142 * leaf entries, growing from the bottom up. The variables are never
143 * referenced, the locations accessed purely from helper functions.
144 *
145 * struct xfs_attr_leaf_name_local
146 * struct xfs_attr_leaf_name_remote
147 */
148};
149
150/*
151 * incore, neutral version of the attribute leaf header
152 */
153struct xfs_attr3_icleaf_hdr {
154 __uint32_t forw;
155 __uint32_t back;
156 __uint16_t magic;
157 __uint16_t count;
158 __uint16_t usedbytes;
159 __uint16_t firstused;
160 __u8 holes;
161 struct {
162 __uint16_t base;
163 __uint16_t size;
164 } freemap[XFS_ATTR_LEAF_MAPSIZE];
165};
166
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167/*
168 * Flags used in the leaf_entry[i].flags field.
169 * NOTE: the INCOMPLETE bit must not collide with the flags bits specified
170 * on the system call, they are "or"ed together for various operations.
171 */
172#define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */
173#define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */
174#define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */
175#define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */
176#define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT)
177#define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT)
178#define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT)
179#define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT)
180
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181/*
182 * Conversion macros for converting namespace bits from argument flags
183 * to ondisk flags.
184 */
185#define XFS_ATTR_NSP_ARGS_MASK (ATTR_ROOT | ATTR_SECURE)
186#define XFS_ATTR_NSP_ONDISK_MASK (XFS_ATTR_ROOT | XFS_ATTR_SECURE)
187#define XFS_ATTR_NSP_ONDISK(flags) ((flags) & XFS_ATTR_NSP_ONDISK_MASK)
188#define XFS_ATTR_NSP_ARGS(flags) ((flags) & XFS_ATTR_NSP_ARGS_MASK)
189#define XFS_ATTR_NSP_ARGS_TO_ONDISK(x) (((x) & ATTR_ROOT ? XFS_ATTR_ROOT : 0) |\
190 ((x) & ATTR_SECURE ? XFS_ATTR_SECURE : 0))
191#define XFS_ATTR_NSP_ONDISK_TO_ARGS(x) (((x) & XFS_ATTR_ROOT ? ATTR_ROOT : 0) |\
192 ((x) & XFS_ATTR_SECURE ? ATTR_SECURE : 0))
193
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194/*
195 * Alignment for namelist and valuelist entries (since they are mixed
196 * there can be only one alignment value)
197 */
198#define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t))
199
517c2220
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200static inline int
201xfs_attr3_leaf_hdr_size(struct xfs_attr_leafblock *leafp)
202{
203 if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
204 return sizeof(struct xfs_attr3_leaf_hdr);
205 return sizeof(struct xfs_attr_leaf_hdr);
206}
207
208static inline struct xfs_attr_leaf_entry *
209xfs_attr3_leaf_entryp(xfs_attr_leafblock_t *leafp)
210{
211 if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
212 return &((struct xfs_attr3_leafblock *)leafp)->entries[0];
213 return &leafp->entries[0];
214}
215
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216/*
217 * Cast typed pointers for "local" and "remote" name/value structs.
218 */
517c2220
DC
219static inline char *
220xfs_attr3_leaf_name(xfs_attr_leafblock_t *leafp, int idx)
a844f451 221{
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DC
222 struct xfs_attr_leaf_entry *entries = xfs_attr3_leaf_entryp(leafp);
223
224 return &((char *)leafp)[be16_to_cpu(entries[idx].nameidx)];
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225}
226
517c2220
DC
227static inline xfs_attr_leaf_name_remote_t *
228xfs_attr3_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx)
a844f451 229{
517c2220 230 return (xfs_attr_leaf_name_remote_t *)xfs_attr3_leaf_name(leafp, idx);
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231}
232
517c2220
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233static inline xfs_attr_leaf_name_local_t *
234xfs_attr3_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx)
a844f451 235{
517c2220 236 return (xfs_attr_leaf_name_local_t *)xfs_attr3_leaf_name(leafp, idx);
a844f451 237}
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238
239/*
240 * Calculate total bytes used (including trailing pad for alignment) for
241 * a "local" name/value structure, a "remote" name/value structure, and
242 * a pointer which might be either.
243 */
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244static inline int xfs_attr_leaf_entsize_remote(int nlen)
245{
246 return ((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \
247 XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1);
248}
249
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250static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen)
251{
252 return ((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) +
253 XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1);
254}
255
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256static inline int xfs_attr_leaf_entsize_local_max(int bsize)
257{
258 return (((bsize) >> 1) + ((bsize) >> 2));
259}
1da177e4 260
1da177e4
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261/*
262 * Used to keep a list of "remote value" extents when unlinking an inode.
263 */
264typedef struct xfs_attr_inactive_list {
265 xfs_dablk_t valueblk; /* block number of value bytes */
266 int valuelen; /* number of bytes in value */
267} xfs_attr_inactive_list_t;
268
269
270/*========================================================================
271 * Function prototypes for the kernel.
272 *========================================================================*/
273
274/*
d8cc890d 275 * Internal routines when attribute fork size < XFS_LITINO(mp).
1da177e4 276 */
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277void xfs_attr_shortform_create(struct xfs_da_args *args);
278void xfs_attr_shortform_add(struct xfs_da_args *args, int forkoff);
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279int xfs_attr_shortform_lookup(struct xfs_da_args *args);
280int xfs_attr_shortform_getvalue(struct xfs_da_args *args);
281int xfs_attr_shortform_to_leaf(struct xfs_da_args *args);
d8cc890d 282int xfs_attr_shortform_remove(struct xfs_da_args *args);
1da177e4 283int xfs_attr_shortform_list(struct xfs_attr_list_context *context);
1d9025e5 284int xfs_attr_shortform_allfit(struct xfs_buf *bp, struct xfs_inode *dp);
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285int xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes);
286
1da177e4
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287
288/*
d8cc890d 289 * Internal routines when attribute fork size == XFS_LBSIZE(mp).
1da177e4 290 */
517c2220
DC
291int xfs_attr3_leaf_to_node(struct xfs_da_args *args);
292int xfs_attr3_leaf_to_shortform(struct xfs_buf *bp,
d8cc890d 293 struct xfs_da_args *args, int forkoff);
517c2220
DC
294int xfs_attr3_leaf_clearflag(struct xfs_da_args *args);
295int xfs_attr3_leaf_setflag(struct xfs_da_args *args);
296int xfs_attr3_leaf_flipflags(struct xfs_da_args *args);
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297
298/*
299 * Routines used for growing the Btree.
300 */
517c2220 301int xfs_attr3_leaf_split(struct xfs_da_state *state,
1da177e4
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302 struct xfs_da_state_blk *oldblk,
303 struct xfs_da_state_blk *newblk);
517c2220 304int xfs_attr3_leaf_lookup_int(struct xfs_buf *leaf,
1da177e4 305 struct xfs_da_args *args);
517c2220
DC
306int xfs_attr3_leaf_getvalue(struct xfs_buf *bp, struct xfs_da_args *args);
307int xfs_attr3_leaf_add(struct xfs_buf *leaf_buffer,
1da177e4 308 struct xfs_da_args *args);
517c2220 309int xfs_attr3_leaf_remove(struct xfs_buf *leaf_buffer,
1da177e4 310 struct xfs_da_args *args);
517c2220 311int xfs_attr3_leaf_list_int(struct xfs_buf *bp,
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312 struct xfs_attr_list_context *context);
313
314/*
315 * Routines used for shrinking the Btree.
316 */
517c2220
DC
317int xfs_attr3_leaf_toosmall(struct xfs_da_state *state, int *retval);
318void xfs_attr3_leaf_unbalance(struct xfs_da_state *state,
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LT
319 struct xfs_da_state_blk *drop_blk,
320 struct xfs_da_state_blk *save_blk);
517c2220 321int xfs_attr3_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp);
1da177e4
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322
323/*
324 * Utility routines.
325 */
1d9025e5
DC
326xfs_dahash_t xfs_attr_leaf_lasthash(struct xfs_buf *bp, int *count);
327int xfs_attr_leaf_order(struct xfs_buf *leaf1_bp,
328 struct xfs_buf *leaf2_bp);
aa82daa0 329int xfs_attr_leaf_newentsize(int namelen, int valuelen, int blocksize,
1da177e4 330 int *local);
517c2220 331int xfs_attr3_leaf_read(struct xfs_trans *tp, struct xfs_inode *dp,
d9392a4b
DC
332 xfs_dablk_t bno, xfs_daddr_t mappedbno,
333 struct xfs_buf **bpp);
517c2220
DC
334void xfs_attr3_leaf_hdr_from_disk(struct xfs_attr3_icleaf_hdr *to,
335 struct xfs_attr_leafblock *from);
1813dd64 336
517c2220 337extern const struct xfs_buf_ops xfs_attr3_leaf_buf_ops;
d9392a4b 338
1da177e4 339#endif /* __XFS_ATTR_LEAF_H__ */