1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/ufs/ialloc.c
4 *
5 * Copyright (c) 1998
6 * Daniel Pirkl <daniel.pirkl@email.cz>
7 * Charles University, Faculty of Mathematics and Physics
8 *
9 * from
10 *
11 * linux/fs/ext2/ialloc.c
12 *
13 * Copyright (C) 1992, 1993, 1994, 1995
14 * Remy Card (card@masi.ibp.fr)
15 * Laboratoire MASI - Institut Blaise Pascal
16 * Universite Pierre et Marie Curie (Paris VI)
17 *
18 * BSD ufs-inspired inode and directory allocation by
19 * Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
20 * Big-endian to little-endian byte-swapping/bitmaps by
21 * David S. Miller (davem@caip.rutgers.edu), 1995
22 *
23 * UFS2 write support added by
24 * Evgeniy Dushistov <dushistov@mail.ru>, 2007
25 */
26
27 #include <linux/fs.h>
28 #include <linux/time.h>
29 #include <linux/stat.h>
30 #include <linux/string.h>
31 #include <linux/buffer_head.h>
32 #include <linux/sched.h>
33 #include <linux/bitops.h>
34 #include <asm/byteorder.h>
35
36 #include "ufs_fs.h"
37 #include "ufs.h"
38 #include "swab.h"
39 #include "util.h"
40
41 /*
42 * NOTE! When we get the inode, we're the only people
43 * that have access to it, and as such there are no
44 * race conditions we have to worry about. The inode
45 * is not on the hash-lists, and it cannot be reached
46 * through the filesystem because the directory entry
47 * has been deleted earlier.
48 *
49 * HOWEVER: we must make sure that we get no aliases,
50 * which means that we have to call "clear_inode()"
51 * _before_ we mark the inode not in use in the inode
52 * bitmaps. Otherwise a newly created file might use
53 * the same inode number (not actually the same pointer
54 * though), and then we'd have two inodes sharing the
55 * same inode number and space on the harddisk.
56 */
ufs_free_inode(struct inode * inode)57 void ufs_free_inode (struct inode * inode)
58 {
59 struct super_block * sb;
60 struct ufs_sb_private_info * uspi;
61 struct ufs_cg_private_info * ucpi;
62 struct ufs_cylinder_group * ucg;
63 int is_directory;
64 unsigned ino, cg, bit;
65
66 UFSD("ENTER, ino %lu\n", inode->i_ino);
67
68 sb = inode->i_sb;
69 uspi = UFS_SB(sb)->s_uspi;
70
71 ino = inode->i_ino;
72
73 mutex_lock(&UFS_SB(sb)->s_lock);
74
75 if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
76 ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
77 mutex_unlock(&UFS_SB(sb)->s_lock);
78 return;
79 }
80
81 cg = ufs_inotocg (ino);
82 bit = ufs_inotocgoff (ino);
83 ucpi = ufs_load_cylinder (sb, cg);
84 if (!ucpi) {
85 mutex_unlock(&UFS_SB(sb)->s_lock);
86 return;
87 }
88 ucg = ubh_get_ucg(UCPI_UBH(ucpi));
89 if (!ufs_cg_chkmagic(sb, ucg))
90 ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
91
92 ucg->cg_time = ufs_get_seconds(sb);
93
94 is_directory = S_ISDIR(inode->i_mode);
95
96 if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
97 ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
98 else {
99 ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
100 if (ino < ucpi->c_irotor)
101 ucpi->c_irotor = ino;
102 fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
103 uspi->cs_total.cs_nifree++;
104 fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
105
106 if (is_directory) {
107 fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
108 uspi->cs_total.cs_ndir--;
109 fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
110 }
111 }
112
113 ubh_mark_buffer_dirty (USPI_UBH(uspi));
114 ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
115 if (sb->s_flags & SB_SYNCHRONOUS)
116 ubh_sync_block(UCPI_UBH(ucpi));
117
118 ufs_mark_sb_dirty(sb);
119 mutex_unlock(&UFS_SB(sb)->s_lock);
120 UFSD("EXIT\n");
121 }
122
123 /*
124 * Nullify new chunk of inodes,
125 * BSD people also set ui_gen field of inode
126 * during nullification, but we not care about
127 * that because of linux ufs do not support NFS
128 */
ufs2_init_inodes_chunk(struct super_block * sb,struct ufs_cg_private_info * ucpi,struct ufs_cylinder_group * ucg)129 static void ufs2_init_inodes_chunk(struct super_block *sb,
130 struct ufs_cg_private_info *ucpi,
131 struct ufs_cylinder_group *ucg)
132 {
133 struct buffer_head *bh;
134 struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
135 sector_t beg = uspi->s_sbbase +
136 ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg +
137 fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk));
138 sector_t end = beg + uspi->s_fpb;
139
140 UFSD("ENTER cgno %d\n", ucpi->c_cgx);
141
142 for (; beg < end; ++beg) {
143 bh = sb_getblk(sb, beg);
144 lock_buffer(bh);
145 memset(bh->b_data, 0, sb->s_blocksize);
146 set_buffer_uptodate(bh);
147 mark_buffer_dirty(bh);
148 unlock_buffer(bh);
149 if (sb->s_flags & SB_SYNCHRONOUS)
150 sync_dirty_buffer(bh);
151 brelse(bh);
152 }
153
154 fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb);
155 ubh_mark_buffer_dirty(UCPI_UBH(ucpi));
156 if (sb->s_flags & SB_SYNCHRONOUS)
157 ubh_sync_block(UCPI_UBH(ucpi));
158
159 UFSD("EXIT\n");
160 }
161
162 /*
163 * There are two policies for allocating an inode. If the new inode is
164 * a directory, then a forward search is made for a block group with both
165 * free space and a low directory-to-inode ratio; if that fails, then of
166 * the groups with above-average free space, that group with the fewest
167 * directories already is chosen.
168 *
169 * For other inodes, search forward from the parent directory's block
170 * group to find a free inode.
171 */
ufs_new_inode(struct inode * dir,umode_t mode)172 struct inode *ufs_new_inode(struct inode *dir, umode_t mode)
173 {
174 struct super_block * sb;
175 struct ufs_sb_info * sbi;
176 struct ufs_sb_private_info * uspi;
177 struct ufs_cg_private_info * ucpi;
178 struct ufs_cylinder_group * ucg;
179 struct inode * inode;
180 struct timespec64 ts;
181 unsigned cg, bit, i, j, start;
182 struct ufs_inode_info *ufsi;
183 int err = -ENOSPC;
184
185 UFSD("ENTER\n");
186
187 /* Cannot create files in a deleted directory */
188 if (!dir || !dir->i_nlink)
189 return ERR_PTR(-EPERM);
190 sb = dir->i_sb;
191 inode = new_inode(sb);
192 if (!inode)
193 return ERR_PTR(-ENOMEM);
194 ufsi = UFS_I(inode);
195 sbi = UFS_SB(sb);
196 uspi = sbi->s_uspi;
197
198 mutex_lock(&sbi->s_lock);
199
200 /*
201 * Try to place the inode in its parent directory
202 */
203 i = ufs_inotocg(dir->i_ino);
204 if (sbi->fs_cs(i).cs_nifree) {
205 cg = i;
206 goto cg_found;
207 }
208
209 /*
210 * Use a quadratic hash to find a group with a free inode
211 */
212 for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
213 i += j;
214 if (i >= uspi->s_ncg)
215 i -= uspi->s_ncg;
216 if (sbi->fs_cs(i).cs_nifree) {
217 cg = i;
218 goto cg_found;
219 }
220 }
221
222 /*
223 * That failed: try linear search for a free inode
224 */
225 i = ufs_inotocg(dir->i_ino) + 1;
226 for (j = 2; j < uspi->s_ncg; j++) {
227 i++;
228 if (i >= uspi->s_ncg)
229 i = 0;
230 if (sbi->fs_cs(i).cs_nifree) {
231 cg = i;
232 goto cg_found;
233 }
234 }
235
236 goto failed;
237
238 cg_found:
239 ucpi = ufs_load_cylinder (sb, cg);
240 if (!ucpi) {
241 err = -EIO;
242 goto failed;
243 }
244 ucg = ubh_get_ucg(UCPI_UBH(ucpi));
245 if (!ufs_cg_chkmagic(sb, ucg))
246 ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
247
248 start = ucpi->c_irotor;
249 bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
250 if (!(bit < uspi->s_ipg)) {
251 bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
252 if (!(bit < start)) {
253 ufs_error (sb, "ufs_new_inode",
254 "cylinder group %u corrupted - error in inode bitmap\n", cg);
255 err = -EIO;
256 goto failed;
257 }
258 }
259 UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
260 if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
261 ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
262 else {
263 ufs_panic (sb, "ufs_new_inode", "internal error");
264 err = -EIO;
265 goto failed;
266 }
267
268 if (uspi->fs_magic == UFS2_MAGIC) {
269 u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk);
270
271 if (bit + uspi->s_inopb > initediblk &&
272 initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk))
273 ufs2_init_inodes_chunk(sb, ucpi, ucg);
274 }
275
276 fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
277 uspi->cs_total.cs_nifree--;
278 fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
279
280 if (S_ISDIR(mode)) {
281 fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
282 uspi->cs_total.cs_ndir++;
283 fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
284 }
285 ubh_mark_buffer_dirty (USPI_UBH(uspi));
286 ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
287 if (sb->s_flags & SB_SYNCHRONOUS)
288 ubh_sync_block(UCPI_UBH(ucpi));
289 ufs_mark_sb_dirty(sb);
290
291 inode->i_ino = cg * uspi->s_ipg + bit;
292 inode_init_owner(inode, dir, mode);
293 inode->i_blocks = 0;
294 inode->i_generation = 0;
295 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
296 ufsi->i_flags = UFS_I(dir)->i_flags;
297 ufsi->i_lastfrag = 0;
298 ufsi->i_shadow = 0;
299 ufsi->i_osync = 0;
300 ufsi->i_oeftflag = 0;
301 ufsi->i_dir_start_lookup = 0;
302 memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
303 if (insert_inode_locked(inode) < 0) {
304 err = -EIO;
305 goto failed;
306 }
307 mark_inode_dirty(inode);
308
309 if (uspi->fs_magic == UFS2_MAGIC) {
310 struct buffer_head *bh;
311 struct ufs2_inode *ufs2_inode;
312
313 /*
314 * setup birth date, we do it here because of there is no sense
315 * to hold it in struct ufs_inode_info, and lose 64 bit
316 */
317 bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
318 if (!bh) {
319 ufs_warning(sb, "ufs_read_inode",
320 "unable to read inode %lu\n",
321 inode->i_ino);
322 err = -EIO;
323 goto fail_remove_inode;
324 }
325 lock_buffer(bh);
326 ufs2_inode = (struct ufs2_inode *)bh->b_data;
327 ufs2_inode += ufs_inotofsbo(inode->i_ino);
328 ktime_get_real_ts64(&ts);
329 ufs2_inode->ui_birthtime = cpu_to_fs64(sb, ts.tv_sec);
330 ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, ts.tv_nsec);
331 mark_buffer_dirty(bh);
332 unlock_buffer(bh);
333 if (sb->s_flags & SB_SYNCHRONOUS)
334 sync_dirty_buffer(bh);
335 brelse(bh);
336 }
337 mutex_unlock(&sbi->s_lock);
338
339 UFSD("allocating inode %lu\n", inode->i_ino);
340 UFSD("EXIT\n");
341 return inode;
342
343 fail_remove_inode:
344 mutex_unlock(&sbi->s_lock);
345 clear_nlink(inode);
346 discard_new_inode(inode);
347 UFSD("EXIT (FAILED): err %d\n", err);
348 return ERR_PTR(err);
349 failed:
350 mutex_unlock(&sbi->s_lock);
351 make_bad_inode(inode);
352 iput (inode);
353 UFSD("EXIT (FAILED): err %d\n", err);
354 return ERR_PTR(err);
355 }
356