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Linux/fs/ufs/ialloc.c

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  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  */
 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 = cpu_to_fs32(sb, get_seconds());
 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  */
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  */
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         unlock_new_inode(inode);
347         iput(inode);
348         UFSD("EXIT (FAILED): err %d\n", err);
349         return ERR_PTR(err);
350 failed:
351         mutex_unlock(&sbi->s_lock);
352         make_bad_inode(inode);
353         iput (inode);
354         UFSD("EXIT (FAILED): err %d\n", err);
355         return ERR_PTR(err);
356 }
357 

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