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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 */
61void 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;
Evgeniy7b4ee732006-01-14 11:42:06 +030075 usb1 = ubh_get_usb_first(uspi);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
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) {
Jan Kara096125f32005-09-06 15:19:15 -0700127 ubh_ll_rw_block (SWRITE, 1, (struct ufs_buffer_head **) &ucpi);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 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 */
146struct inode * ufs_new_inode(struct inode * dir, int mode)
147{
148 struct super_block * sb;
149 struct ufs_sb_info * sbi;
150 struct ufs_sb_private_info * uspi;
151 struct ufs_super_block_first * usb1;
152 struct ufs_cg_private_info * ucpi;
153 struct ufs_cylinder_group * ucg;
154 struct inode * inode;
155 unsigned cg, bit, i, j, start;
156 struct ufs_inode_info *ufsi;
157
158 UFSD(("ENTER\n"))
159
160 /* Cannot create files in a deleted directory */
161 if (!dir || !dir->i_nlink)
162 return ERR_PTR(-EPERM);
163 sb = dir->i_sb;
164 inode = new_inode(sb);
165 if (!inode)
166 return ERR_PTR(-ENOMEM);
167 ufsi = UFS_I(inode);
168 sbi = UFS_SB(sb);
169 uspi = sbi->s_uspi;
Evgeniy7b4ee732006-01-14 11:42:06 +0300170 usb1 = ubh_get_usb_first(uspi);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
172 lock_super (sb);
173
174 /*
175 * Try to place the inode in its parent directory
176 */
177 i = ufs_inotocg(dir->i_ino);
178 if (sbi->fs_cs(i).cs_nifree) {
179 cg = i;
180 goto cg_found;
181 }
182
183 /*
184 * Use a quadratic hash to find a group with a free inode
185 */
186 for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
187 i += j;
188 if (i >= uspi->s_ncg)
189 i -= uspi->s_ncg;
190 if (sbi->fs_cs(i).cs_nifree) {
191 cg = i;
192 goto cg_found;
193 }
194 }
195
196 /*
197 * That failed: try linear search for a free inode
198 */
199 i = ufs_inotocg(dir->i_ino) + 1;
200 for (j = 2; j < uspi->s_ncg; j++) {
201 i++;
202 if (i >= uspi->s_ncg)
203 i = 0;
204 if (sbi->fs_cs(i).cs_nifree) {
205 cg = i;
206 goto cg_found;
207 }
208 }
209
210 goto failed;
211
212cg_found:
213 ucpi = ufs_load_cylinder (sb, cg);
214 if (!ucpi)
215 goto failed;
216 ucg = ubh_get_ucg(UCPI_UBH);
217 if (!ufs_cg_chkmagic(sb, ucg))
218 ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
219
220 start = ucpi->c_irotor;
221 bit = ubh_find_next_zero_bit (UCPI_UBH, ucpi->c_iusedoff, uspi->s_ipg, start);
222 if (!(bit < uspi->s_ipg)) {
223 bit = ubh_find_first_zero_bit (UCPI_UBH, ucpi->c_iusedoff, start);
224 if (!(bit < start)) {
225 ufs_error (sb, "ufs_new_inode",
226 "cylinder group %u corrupted - error in inode bitmap\n", cg);
227 goto failed;
228 }
229 }
230 UFSD(("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg))
231 if (ubh_isclr (UCPI_UBH, ucpi->c_iusedoff, bit))
232 ubh_setbit (UCPI_UBH, ucpi->c_iusedoff, bit);
233 else {
234 ufs_panic (sb, "ufs_new_inode", "internal error");
235 goto failed;
236 }
237
238 fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
239 fs32_sub(sb, &usb1->fs_cstotal.cs_nifree, 1);
240 fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
241
242 if (S_ISDIR(mode)) {
243 fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
244 fs32_add(sb, &usb1->fs_cstotal.cs_ndir, 1);
245 fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
246 }
247
248 ubh_mark_buffer_dirty (USPI_UBH);
249 ubh_mark_buffer_dirty (UCPI_UBH);
250 if (sb->s_flags & MS_SYNCHRONOUS) {
Jan Kara096125f32005-09-06 15:19:15 -0700251 ubh_ll_rw_block (SWRITE, 1, (struct ufs_buffer_head **) &ucpi);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 ubh_wait_on_buffer (UCPI_UBH);
253 }
254 sb->s_dirt = 1;
255
256 inode->i_mode = mode;
257 inode->i_uid = current->fsuid;
258 if (dir->i_mode & S_ISGID) {
259 inode->i_gid = dir->i_gid;
260 if (S_ISDIR(mode))
261 inode->i_mode |= S_ISGID;
262 } else
263 inode->i_gid = current->fsgid;
264
265 inode->i_ino = cg * uspi->s_ipg + bit;
266 inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size (for stat), not the fs block size */
267 inode->i_blocks = 0;
268 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
269 ufsi->i_flags = UFS_I(dir)->i_flags;
270 ufsi->i_lastfrag = 0;
271 ufsi->i_gen = 0;
272 ufsi->i_shadow = 0;
273 ufsi->i_osync = 0;
274 ufsi->i_oeftflag = 0;
275 memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
276
277 insert_inode_hash(inode);
278 mark_inode_dirty(inode);
279
280 unlock_super (sb);
281
282 if (DQUOT_ALLOC_INODE(inode)) {
283 DQUOT_DROP(inode);
284 inode->i_flags |= S_NOQUOTA;
285 inode->i_nlink = 0;
286 iput(inode);
287 return ERR_PTR(-EDQUOT);
288 }
289
290 UFSD(("allocating inode %lu\n", inode->i_ino))
291 UFSD(("EXIT\n"))
292 return inode;
293
294failed:
295 unlock_super (sb);
296 make_bad_inode(inode);
297 iput (inode);
298 UFSD(("EXIT (FAILED)\n"))
299 return ERR_PTR(-ENOSPC);
300}