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/sched.h>
26 #include <linux/stat.h>
27 #include <linux/string.h>
28 #include <linux/locks.h>
29 #include <linux/quotaops.h>
30 #include <asm/bitops.h>
31 #include <asm/byteorder.h>
32
33 #include "swab.h"
34 #include "util.h"
35
36 #undef UFS_IALLOC_DEBUG
37
38 #ifdef UFS_IALLOC_DEBUG
39 #define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
40 #else
41 #define UFSD(x)
42 #endif
43
44 /*
45 * NOTE! When we get the inode, we're the only people
46 * that have access to it, and as such there are no
47 * race conditions we have to worry about. The inode
48 * is not on the hash-lists, and it cannot be reached
49 * through the filesystem because the directory entry
50 * has been deleted earlier.
51 *
52 * HOWEVER: we must make sure that we get no aliases,
53 * which means that we have to call "clear_inode()"
54 * _before_ we mark the inode not in use in the inode
55 * bitmaps. Otherwise a newly created file might use
56 * the same inode number (not actually the same pointer
57 * though), and then we'd have two inodes sharing the
58 * same inode number and space on the harddisk.
59 */
60 void ufs_free_inode (struct inode * inode)
61 {
62 struct super_block * sb;
63 struct ufs_sb_private_info * uspi;
64 struct ufs_super_block_first * usb1;
65 struct ufs_cg_private_info * ucpi;
66 struct ufs_cylinder_group * ucg;
67 int is_directory;
68 unsigned ino, cg, bit;
69 unsigned swab;
70
71 UFSD(("ENTER, ino %lu\n", inode->i_ino))
72
73 sb = inode->i_sb;
74 swab = sb->u.ufs_sb.s_swab;
75 uspi = sb->u.ufs_sb.s_uspi;
76 usb1 = ubh_get_usb_first(USPI_UBH);
77
78 ino = inode->i_ino;
79
80 lock_super (sb);
81
82 if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
83 ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
84 unlock_super (sb);
85 return;
86 }
87
88 cg = ufs_inotocg (ino);
89 bit = ufs_inotocgoff (ino);
90 ucpi = ufs_load_cylinder (sb, cg);
91 if (!ucpi) {
92 unlock_super (sb);
93 return;
94 }
95 ucg = ubh_get_ucg(UCPI_UBH);
96 if (!ufs_cg_chkmagic(ucg))
97 ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
98
99 ucg->cg_time = SWAB32(CURRENT_TIME);
100
101 is_directory = S_ISDIR(inode->i_mode);
102
103 DQUOT_FREE_INODE(sb, inode);
104 DQUOT_DROP(inode);
105
106 clear_inode (inode);
107
108 if (ubh_isclr (UCPI_UBH, ucpi->c_iusedoff, bit))
109 ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
110 else {
111 ubh_clrbit (UCPI_UBH, ucpi->c_iusedoff, bit);
112 if (ino < ucpi->c_irotor)
113 ucpi->c_irotor = ino;
114 INC_SWAB32(ucg->cg_cs.cs_nifree);
115 INC_SWAB32(usb1->fs_cstotal.cs_nifree);
116 INC_SWAB32(sb->fs_cs(cg).cs_nifree);
117
118 if (is_directory) {
119 DEC_SWAB32(ucg->cg_cs.cs_ndir);
120 DEC_SWAB32(usb1->fs_cstotal.cs_ndir);
121 DEC_SWAB32(sb->fs_cs(cg).cs_ndir);
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_ll_rw_block (WRITE, 1, (struct ufs_buffer_head **) &ucpi);
128 ubh_wait_on_buffer (UCPI_UBH);
129 }
130
131 sb->s_dirt = 1;
132 unlock_super (sb);
133 UFSD(("EXIT\n"))
134 }
135
136 /*
137 * There are two policies for allocating an inode. If the new inode is
138 * a directory, then a forward search is made for a block group with both
139 * free space and a low directory-to-inode ratio; if that fails, then of
140 * the groups with above-average free space, that group with the fewest
141 * directories already is chosen.
142 *
143 * For other inodes, search forward from the parent directory's block
144 * group to find a free inode.
145 */
146 struct inode * ufs_new_inode (const struct inode * dir, int mode, int * err )
147 {
148 struct super_block * sb;
149 struct ufs_sb_private_info * uspi;
150 struct ufs_super_block_first * usb1;
151 struct ufs_cg_private_info * ucpi;
152 struct ufs_cylinder_group * ucg;
153 struct inode * inode;
154 unsigned cg, bit, i, j, start;
155 unsigned swab;
156
157 UFSD(("ENTER\n"))
158
159 /* Cannot create files in a deleted directory */
160 if (!dir || !dir->i_nlink) {
161 *err = -EPERM;
162 return NULL;
163 }
164 sb = dir->i_sb;
165 inode = new_inode(sb);
166 if (!inode) {
167 *err = -ENOMEM;
168 return NULL;
169 }
170 swab = sb->u.ufs_sb.s_swab;
171 uspi = sb->u.ufs_sb.s_uspi;
172 usb1 = ubh_get_usb_first(USPI_UBH);
173
174 lock_super (sb);
175
176 *err = -ENOSPC;
177
178 /*
179 * Try to place the inode in its parent directory
180 */
181 i = ufs_inotocg(dir->i_ino);
182 if (SWAB32(sb->fs_cs(i).cs_nifree)) {
183 cg = i;
184 goto cg_found;
185 }
186
187 /*
188 * Use a quadratic hash to find a group with a free inode
189 */
190 for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
191 i += j;
192 if (i >= uspi->s_ncg)
193 i -= uspi->s_ncg;
194 if (SWAB32(sb->fs_cs(i).cs_nifree)) {
195 cg = i;
196 goto cg_found;
197 }
198 }
199
200 /*
201 * That failed: try linear search for a free inode
202 */
203 i = ufs_inotocg(dir->i_ino) + 1;
204 for (j = 2; j < uspi->s_ncg; j++) {
205 i++;
206 if (i >= uspi->s_ncg)
207 i = 0;
208 if (SWAB32(sb->fs_cs(i).cs_nifree)) {
209 cg = i;
210 goto cg_found;
211 }
212 }
213
214 goto failed;
215
216 cg_found:
217 ucpi = ufs_load_cylinder (sb, cg);
218 if (!ucpi)
219 goto failed;
220 ucg = ubh_get_ucg(UCPI_UBH);
221 if (!ufs_cg_chkmagic(ucg))
222 ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
223
224 start = ucpi->c_irotor;
225 bit = ubh_find_next_zero_bit (UCPI_UBH, ucpi->c_iusedoff, uspi->s_ipg, start);
226 if (!(bit < uspi->s_ipg)) {
227 bit = ubh_find_first_zero_bit (UCPI_UBH, ucpi->c_iusedoff, start);
228 if (!(bit < start)) {
229 ufs_error (sb, "ufs_new_inode",
230 "cylinder group %u corrupted - error in inode bitmap\n", cg);
231 goto failed;
232 }
233 }
234 UFSD(("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg))
235 if (ubh_isclr (UCPI_UBH, ucpi->c_iusedoff, bit))
236 ubh_setbit (UCPI_UBH, ucpi->c_iusedoff, bit);
237 else {
238 ufs_panic (sb, "ufs_new_inode", "internal error");
239 goto failed;
240 }
241
242 DEC_SWAB32(ucg->cg_cs.cs_nifree);
243 DEC_SWAB32(usb1->fs_cstotal.cs_nifree);
244 DEC_SWAB32(sb->fs_cs(cg).cs_nifree);
245
246 if (S_ISDIR(mode)) {
247 INC_SWAB32(ucg->cg_cs.cs_ndir);
248 INC_SWAB32(usb1->fs_cstotal.cs_ndir);
249 INC_SWAB32(sb->fs_cs(cg).cs_ndir);
250 }
251
252 ubh_mark_buffer_dirty (USPI_UBH);
253 ubh_mark_buffer_dirty (UCPI_UBH);
254 if (sb->s_flags & MS_SYNCHRONOUS) {
255 ubh_ll_rw_block (WRITE, 1, (struct ufs_buffer_head **) &ucpi);
256 ubh_wait_on_buffer (UCPI_UBH);
257 }
258 sb->s_dirt = 1;
259
260 inode->i_mode = mode;
261 inode->i_uid = current->fsuid;
262 if (dir->i_mode & S_ISGID) {
263 inode->i_gid = dir->i_gid;
264 if (S_ISDIR(mode))
265 mode |= S_ISGID;
266 } else
267 inode->i_gid = current->fsgid;
268
269 inode->i_ino = cg * uspi->s_ipg + bit;
270 inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size (for stat), not the fs block size */
271 inode->i_blocks = 0;
272 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
273 inode->u.ufs_i.i_flags = dir->u.ufs_i.i_flags;
274 inode->u.ufs_i.i_lastfrag = 0;
275
276 insert_inode_hash(inode);
277 mark_inode_dirty(inode);
278
279 unlock_super (sb);
280
281 if(DQUOT_ALLOC_INODE(sb, inode)) {
282 sb->dq_op->drop(inode);
283 inode->i_nlink = 0;
284 iput(inode);
285 *err = -EDQUOT;
286 return NULL;
287 }
288
289 UFSD(("allocating inode %lu\n", inode->i_ino))
290 *err = 0;
291 UFSD(("EXIT\n"))
292 return inode;
293
294 failed:
295 unlock_super (sb);
296 iput (inode);
297 UFSD(("EXIT (FAILED)\n"))
298 return NULL;
299 }
300
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