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1da177e4 LT |
1 | /* |
2 | * linux/fs/ufs/ialloc.c | |
3 | * | |
4 | * Copyright (c) 1998 | |
5 | * Daniel Pirkl <daniel.pirkl@email.cz> | |
6 | * Charles University, Faculty of Mathematics and Physics | |
7 | * | |
8 | * from | |
9 | * | |
10 | * linux/fs/ext2/ialloc.c | |
11 | * | |
12 | * Copyright (C) 1992, 1993, 1994, 1995 | |
13 | * Remy Card (card@masi.ibp.fr) | |
14 | * Laboratoire MASI - Institut Blaise Pascal | |
15 | * Universite Pierre et Marie Curie (Paris VI) | |
16 | * | |
17 | * BSD ufs-inspired inode and directory allocation by | |
18 | * Stephen Tweedie (sct@dcs.ed.ac.uk), 1993 | |
19 | * Big-endian to little-endian byte-swapping/bitmaps by | |
20 | * David S. Miller (davem@caip.rutgers.edu), 1995 | |
21 | */ | |
22 | ||
23 | #include <linux/fs.h> | |
24 | #include <linux/ufs_fs.h> | |
25 | #include <linux/time.h> | |
26 | #include <linux/stat.h> | |
27 | #include <linux/string.h> | |
28 | #include <linux/quotaops.h> | |
29 | #include <linux/buffer_head.h> | |
30 | #include <linux/sched.h> | |
31 | #include <linux/bitops.h> | |
32 | #include <asm/byteorder.h> | |
33 | ||
34 | #include "swab.h" | |
35 | #include "util.h" | |
36 | ||
37 | #undef UFS_IALLOC_DEBUG | |
38 | ||
39 | #ifdef UFS_IALLOC_DEBUG | |
40 | #define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x; | |
41 | #else | |
42 | #define UFSD(x) | |
43 | #endif | |
44 | ||
45 | /* | |
46 | * NOTE! When we get the inode, we're the only people | |
47 | * that have access to it, and as such there are no | |
48 | * race conditions we have to worry about. The inode | |
49 | * is not on the hash-lists, and it cannot be reached | |
50 | * through the filesystem because the directory entry | |
51 | * has been deleted earlier. | |
52 | * | |
53 | * HOWEVER: we must make sure that we get no aliases, | |
54 | * which means that we have to call "clear_inode()" | |
55 | * _before_ we mark the inode not in use in the inode | |
56 | * bitmaps. Otherwise a newly created file might use | |
57 | * the same inode number (not actually the same pointer | |
58 | * though), and then we'd have two inodes sharing the | |
59 | * same inode number and space on the harddisk. | |
60 | */ | |
61 | void ufs_free_inode (struct inode * inode) | |
62 | { | |
63 | struct super_block * sb; | |
64 | struct ufs_sb_private_info * uspi; | |
65 | struct ufs_super_block_first * usb1; | |
66 | struct ufs_cg_private_info * ucpi; | |
67 | struct ufs_cylinder_group * ucg; | |
68 | int is_directory; | |
69 | unsigned ino, cg, bit; | |
70 | ||
71 | UFSD(("ENTER, ino %lu\n", inode->i_ino)) | |
72 | ||
73 | sb = inode->i_sb; | |
74 | uspi = UFS_SB(sb)->s_uspi; | |
75 | usb1 = ubh_get_usb_first(USPI_UBH); | |
76 | ||
77 | ino = inode->i_ino; | |
78 | ||
79 | lock_super (sb); | |
80 | ||
81 | if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) { | |
82 | ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino); | |
83 | unlock_super (sb); | |
84 | return; | |
85 | } | |
86 | ||
87 | cg = ufs_inotocg (ino); | |
88 | bit = ufs_inotocgoff (ino); | |
89 | ucpi = ufs_load_cylinder (sb, cg); | |
90 | if (!ucpi) { | |
91 | unlock_super (sb); | |
92 | return; | |
93 | } | |
94 | ucg = ubh_get_ucg(UCPI_UBH); | |
95 | if (!ufs_cg_chkmagic(sb, ucg)) | |
96 | ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number"); | |
97 | ||
98 | ucg->cg_time = cpu_to_fs32(sb, get_seconds()); | |
99 | ||
100 | is_directory = S_ISDIR(inode->i_mode); | |
101 | ||
102 | DQUOT_FREE_INODE(inode); | |
103 | DQUOT_DROP(inode); | |
104 | ||
105 | clear_inode (inode); | |
106 | ||
107 | if (ubh_isclr (UCPI_UBH, ucpi->c_iusedoff, bit)) | |
108 | ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino); | |
109 | else { | |
110 | ubh_clrbit (UCPI_UBH, ucpi->c_iusedoff, bit); | |
111 | if (ino < ucpi->c_irotor) | |
112 | ucpi->c_irotor = ino; | |
113 | fs32_add(sb, &ucg->cg_cs.cs_nifree, 1); | |
114 | fs32_add(sb, &usb1->fs_cstotal.cs_nifree, 1); | |
115 | fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1); | |
116 | ||
117 | if (is_directory) { | |
118 | fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1); | |
119 | fs32_sub(sb, &usb1->fs_cstotal.cs_ndir, 1); | |
120 | fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1); | |
121 | } | |
122 | } | |
123 | ||
124 | ubh_mark_buffer_dirty (USPI_UBH); | |
125 | ubh_mark_buffer_dirty (UCPI_UBH); | |
126 | if (sb->s_flags & MS_SYNCHRONOUS) { | |
127 | ubh_wait_on_buffer (UCPI_UBH); | |
128 | ubh_ll_rw_block (WRITE, 1, (struct ufs_buffer_head **) &ucpi); | |
129 | ubh_wait_on_buffer (UCPI_UBH); | |
130 | } | |
131 | ||
132 | sb->s_dirt = 1; | |
133 | unlock_super (sb); | |
134 | UFSD(("EXIT\n")) | |
135 | } | |
136 | ||
137 | /* | |
138 | * There are two policies for allocating an inode. If the new inode is | |
139 | * a directory, then a forward search is made for a block group with both | |
140 | * free space and a low directory-to-inode ratio; if that fails, then of | |
141 | * the groups with above-average free space, that group with the fewest | |
142 | * directories already is chosen. | |
143 | * | |
144 | * For other inodes, search forward from the parent directory's block | |
145 | * group to find a free inode. | |
146 | */ | |
147 | struct inode * ufs_new_inode(struct inode * dir, int mode) | |
148 | { | |
149 | struct super_block * sb; | |
150 | struct ufs_sb_info * sbi; | |
151 | struct ufs_sb_private_info * uspi; | |
152 | struct ufs_super_block_first * usb1; | |
153 | struct ufs_cg_private_info * ucpi; | |
154 | struct ufs_cylinder_group * ucg; | |
155 | struct inode * inode; | |
156 | unsigned cg, bit, i, j, start; | |
157 | struct ufs_inode_info *ufsi; | |
158 | ||
159 | UFSD(("ENTER\n")) | |
160 | ||
161 | /* Cannot create files in a deleted directory */ | |
162 | if (!dir || !dir->i_nlink) | |
163 | return ERR_PTR(-EPERM); | |
164 | sb = dir->i_sb; | |
165 | inode = new_inode(sb); | |
166 | if (!inode) | |
167 | return ERR_PTR(-ENOMEM); | |
168 | ufsi = UFS_I(inode); | |
169 | sbi = UFS_SB(sb); | |
170 | uspi = sbi->s_uspi; | |
171 | usb1 = ubh_get_usb_first(USPI_UBH); | |
172 | ||
173 | lock_super (sb); | |
174 | ||
175 | /* | |
176 | * Try to place the inode in its parent directory | |
177 | */ | |
178 | i = ufs_inotocg(dir->i_ino); | |
179 | if (sbi->fs_cs(i).cs_nifree) { | |
180 | cg = i; | |
181 | goto cg_found; | |
182 | } | |
183 | ||
184 | /* | |
185 | * Use a quadratic hash to find a group with a free inode | |
186 | */ | |
187 | for ( j = 1; j < uspi->s_ncg; j <<= 1 ) { | |
188 | i += j; | |
189 | if (i >= uspi->s_ncg) | |
190 | i -= uspi->s_ncg; | |
191 | if (sbi->fs_cs(i).cs_nifree) { | |
192 | cg = i; | |
193 | goto cg_found; | |
194 | } | |
195 | } | |
196 | ||
197 | /* | |
198 | * That failed: try linear search for a free inode | |
199 | */ | |
200 | i = ufs_inotocg(dir->i_ino) + 1; | |
201 | for (j = 2; j < uspi->s_ncg; j++) { | |
202 | i++; | |
203 | if (i >= uspi->s_ncg) | |
204 | i = 0; | |
205 | if (sbi->fs_cs(i).cs_nifree) { | |
206 | cg = i; | |
207 | goto cg_found; | |
208 | } | |
209 | } | |
210 | ||
211 | goto failed; | |
212 | ||
213 | cg_found: | |
214 | ucpi = ufs_load_cylinder (sb, cg); | |
215 | if (!ucpi) | |
216 | goto failed; | |
217 | ucg = ubh_get_ucg(UCPI_UBH); | |
218 | if (!ufs_cg_chkmagic(sb, ucg)) | |
219 | ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number"); | |
220 | ||
221 | start = ucpi->c_irotor; | |
222 | bit = ubh_find_next_zero_bit (UCPI_UBH, ucpi->c_iusedoff, uspi->s_ipg, start); | |
223 | if (!(bit < uspi->s_ipg)) { | |
224 | bit = ubh_find_first_zero_bit (UCPI_UBH, ucpi->c_iusedoff, start); | |
225 | if (!(bit < start)) { | |
226 | ufs_error (sb, "ufs_new_inode", | |
227 | "cylinder group %u corrupted - error in inode bitmap\n", cg); | |
228 | goto failed; | |
229 | } | |
230 | } | |
231 | UFSD(("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg)) | |
232 | if (ubh_isclr (UCPI_UBH, ucpi->c_iusedoff, bit)) | |
233 | ubh_setbit (UCPI_UBH, ucpi->c_iusedoff, bit); | |
234 | else { | |
235 | ufs_panic (sb, "ufs_new_inode", "internal error"); | |
236 | goto failed; | |
237 | } | |
238 | ||
239 | fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1); | |
240 | fs32_sub(sb, &usb1->fs_cstotal.cs_nifree, 1); | |
241 | fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1); | |
242 | ||
243 | if (S_ISDIR(mode)) { | |
244 | fs32_add(sb, &ucg->cg_cs.cs_ndir, 1); | |
245 | fs32_add(sb, &usb1->fs_cstotal.cs_ndir, 1); | |
246 | fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1); | |
247 | } | |
248 | ||
249 | ubh_mark_buffer_dirty (USPI_UBH); | |
250 | ubh_mark_buffer_dirty (UCPI_UBH); | |
251 | if (sb->s_flags & MS_SYNCHRONOUS) { | |
252 | ubh_wait_on_buffer (UCPI_UBH); | |
253 | ubh_ll_rw_block (WRITE, 1, (struct ufs_buffer_head **) &ucpi); | |
254 | ubh_wait_on_buffer (UCPI_UBH); | |
255 | } | |
256 | sb->s_dirt = 1; | |
257 | ||
258 | inode->i_mode = mode; | |
259 | inode->i_uid = current->fsuid; | |
260 | if (dir->i_mode & S_ISGID) { | |
261 | inode->i_gid = dir->i_gid; | |
262 | if (S_ISDIR(mode)) | |
263 | inode->i_mode |= S_ISGID; | |
264 | } else | |
265 | inode->i_gid = current->fsgid; | |
266 | ||
267 | inode->i_ino = cg * uspi->s_ipg + bit; | |
268 | inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size (for stat), not the fs block size */ | |
269 | inode->i_blocks = 0; | |
270 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; | |
271 | ufsi->i_flags = UFS_I(dir)->i_flags; | |
272 | ufsi->i_lastfrag = 0; | |
273 | ufsi->i_gen = 0; | |
274 | ufsi->i_shadow = 0; | |
275 | ufsi->i_osync = 0; | |
276 | ufsi->i_oeftflag = 0; | |
277 | memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1)); | |
278 | ||
279 | insert_inode_hash(inode); | |
280 | mark_inode_dirty(inode); | |
281 | ||
282 | unlock_super (sb); | |
283 | ||
284 | if (DQUOT_ALLOC_INODE(inode)) { | |
285 | DQUOT_DROP(inode); | |
286 | inode->i_flags |= S_NOQUOTA; | |
287 | inode->i_nlink = 0; | |
288 | iput(inode); | |
289 | return ERR_PTR(-EDQUOT); | |
290 | } | |
291 | ||
292 | UFSD(("allocating inode %lu\n", inode->i_ino)) | |
293 | UFSD(("EXIT\n")) | |
294 | return inode; | |
295 | ||
296 | failed: | |
297 | unlock_super (sb); | |
298 | make_bad_inode(inode); | |
299 | iput (inode); | |
300 | UFSD(("EXIT (FAILED)\n")) | |
301 | return ERR_PTR(-ENOSPC); | |
302 | } |