xref: /openbmc/linux/fs/ufs/ialloc.c (revision 82ced6fd)
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   * UFS2 write support added by
23   * Evgeniy Dushistov <dushistov@mail.ru>, 2007
24   */
25  
26  #include <linux/fs.h>
27  #include <linux/time.h>
28  #include <linux/stat.h>
29  #include <linux/string.h>
30  #include <linux/quotaops.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_super_block_first * usb1;
62  	struct ufs_cg_private_info * ucpi;
63  	struct ufs_cylinder_group * ucg;
64  	int is_directory;
65  	unsigned ino, cg, bit;
66  
67  	UFSD("ENTER, ino %lu\n", inode->i_ino);
68  
69  	sb = inode->i_sb;
70  	uspi = UFS_SB(sb)->s_uspi;
71  	usb1 = ubh_get_usb_first(uspi);
72  
73  	ino = inode->i_ino;
74  
75  	lock_super (sb);
76  
77  	if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
78  		ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
79  		unlock_super (sb);
80  		return;
81  	}
82  
83  	cg = ufs_inotocg (ino);
84  	bit = ufs_inotocgoff (ino);
85  	ucpi = ufs_load_cylinder (sb, cg);
86  	if (!ucpi) {
87  		unlock_super (sb);
88  		return;
89  	}
90  	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
91  	if (!ufs_cg_chkmagic(sb, ucg))
92  		ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
93  
94  	ucg->cg_time = cpu_to_fs32(sb, get_seconds());
95  
96  	is_directory = S_ISDIR(inode->i_mode);
97  
98  	vfs_dq_free_inode(inode);
99  	vfs_dq_drop(inode);
100  
101  	clear_inode (inode);
102  
103  	if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
104  		ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
105  	else {
106  		ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
107  		if (ino < ucpi->c_irotor)
108  			ucpi->c_irotor = ino;
109  		fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
110  		uspi->cs_total.cs_nifree++;
111  		fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
112  
113  		if (is_directory) {
114  			fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
115  			uspi->cs_total.cs_ndir--;
116  			fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
117  		}
118  	}
119  
120  	ubh_mark_buffer_dirty (USPI_UBH(uspi));
121  	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
122  	if (sb->s_flags & MS_SYNCHRONOUS) {
123  		ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
124  		ubh_wait_on_buffer (UCPI_UBH(ucpi));
125  	}
126  
127  	sb->s_dirt = 1;
128  	unlock_super (sb);
129  	UFSD("EXIT\n");
130  }
131  
132  /*
133   * Nullify new chunk of inodes,
134   * BSD people also set ui_gen field of inode
135   * during nullification, but we not care about
136   * that because of linux ufs do not support NFS
137   */
138  static void ufs2_init_inodes_chunk(struct super_block *sb,
139  				   struct ufs_cg_private_info *ucpi,
140  				   struct ufs_cylinder_group *ucg)
141  {
142  	struct buffer_head *bh;
143  	struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
144  	sector_t beg = uspi->s_sbbase +
145  		ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg +
146  			      fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk));
147  	sector_t end = beg + uspi->s_fpb;
148  
149  	UFSD("ENTER cgno %d\n", ucpi->c_cgx);
150  
151  	for (; beg < end; ++beg) {
152  		bh = sb_getblk(sb, beg);
153  		lock_buffer(bh);
154  		memset(bh->b_data, 0, sb->s_blocksize);
155  		set_buffer_uptodate(bh);
156  		mark_buffer_dirty(bh);
157  		unlock_buffer(bh);
158  		if (sb->s_flags & MS_SYNCHRONOUS)
159  			sync_dirty_buffer(bh);
160  		brelse(bh);
161  	}
162  
163  	fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb);
164  	ubh_mark_buffer_dirty(UCPI_UBH(ucpi));
165  	if (sb->s_flags & MS_SYNCHRONOUS) {
166  		ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
167  		ubh_wait_on_buffer(UCPI_UBH(ucpi));
168  	}
169  
170  	UFSD("EXIT\n");
171  }
172  
173  /*
174   * There are two policies for allocating an inode.  If the new inode is
175   * a directory, then a forward search is made for a block group with both
176   * free space and a low directory-to-inode ratio; if that fails, then of
177   * the groups with above-average free space, that group with the fewest
178   * directories already is chosen.
179   *
180   * For other inodes, search forward from the parent directory's block
181   * group to find a free inode.
182   */
183  struct inode * ufs_new_inode(struct inode * dir, int mode)
184  {
185  	struct super_block * sb;
186  	struct ufs_sb_info * sbi;
187  	struct ufs_sb_private_info * uspi;
188  	struct ufs_super_block_first * usb1;
189  	struct ufs_cg_private_info * ucpi;
190  	struct ufs_cylinder_group * ucg;
191  	struct inode * inode;
192  	unsigned cg, bit, i, j, start;
193  	struct ufs_inode_info *ufsi;
194  	int err = -ENOSPC;
195  
196  	UFSD("ENTER\n");
197  
198  	/* Cannot create files in a deleted directory */
199  	if (!dir || !dir->i_nlink)
200  		return ERR_PTR(-EPERM);
201  	sb = dir->i_sb;
202  	inode = new_inode(sb);
203  	if (!inode)
204  		return ERR_PTR(-ENOMEM);
205  	ufsi = UFS_I(inode);
206  	sbi = UFS_SB(sb);
207  	uspi = sbi->s_uspi;
208  	usb1 = ubh_get_usb_first(uspi);
209  
210  	lock_super (sb);
211  
212  	/*
213  	 * Try to place the inode in its parent directory
214  	 */
215  	i = ufs_inotocg(dir->i_ino);
216  	if (sbi->fs_cs(i).cs_nifree) {
217  		cg = i;
218  		goto cg_found;
219  	}
220  
221  	/*
222  	 * Use a quadratic hash to find a group with a free inode
223  	 */
224  	for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
225  		i += j;
226  		if (i >= uspi->s_ncg)
227  			i -= uspi->s_ncg;
228  		if (sbi->fs_cs(i).cs_nifree) {
229  			cg = i;
230  			goto cg_found;
231  		}
232  	}
233  
234  	/*
235  	 * That failed: try linear search for a free inode
236  	 */
237  	i = ufs_inotocg(dir->i_ino) + 1;
238  	for (j = 2; j < uspi->s_ncg; j++) {
239  		i++;
240  		if (i >= uspi->s_ncg)
241  			i = 0;
242  		if (sbi->fs_cs(i).cs_nifree) {
243  			cg = i;
244  			goto cg_found;
245  		}
246  	}
247  
248  	goto failed;
249  
250  cg_found:
251  	ucpi = ufs_load_cylinder (sb, cg);
252  	if (!ucpi) {
253  		err = -EIO;
254  		goto failed;
255  	}
256  	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
257  	if (!ufs_cg_chkmagic(sb, ucg))
258  		ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
259  
260  	start = ucpi->c_irotor;
261  	bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
262  	if (!(bit < uspi->s_ipg)) {
263  		bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
264  		if (!(bit < start)) {
265  			ufs_error (sb, "ufs_new_inode",
266  			    "cylinder group %u corrupted - error in inode bitmap\n", cg);
267  			err = -EIO;
268  			goto failed;
269  		}
270  	}
271  	UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
272  	if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
273  		ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
274  	else {
275  		ufs_panic (sb, "ufs_new_inode", "internal error");
276  		err = -EIO;
277  		goto failed;
278  	}
279  
280  	if (uspi->fs_magic == UFS2_MAGIC) {
281  		u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk);
282  
283  		if (bit + uspi->s_inopb > initediblk &&
284  		    initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk))
285  			ufs2_init_inodes_chunk(sb, ucpi, ucg);
286  	}
287  
288  	fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
289  	uspi->cs_total.cs_nifree--;
290  	fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
291  
292  	if (S_ISDIR(mode)) {
293  		fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
294  		uspi->cs_total.cs_ndir++;
295  		fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
296  	}
297  	ubh_mark_buffer_dirty (USPI_UBH(uspi));
298  	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
299  	if (sb->s_flags & MS_SYNCHRONOUS) {
300  		ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
301  		ubh_wait_on_buffer (UCPI_UBH(ucpi));
302  	}
303  	sb->s_dirt = 1;
304  
305  	inode->i_ino = cg * uspi->s_ipg + bit;
306  	inode->i_mode = mode;
307  	inode->i_uid = current_fsuid();
308  	if (dir->i_mode & S_ISGID) {
309  		inode->i_gid = dir->i_gid;
310  		if (S_ISDIR(mode))
311  			inode->i_mode |= S_ISGID;
312  	} else
313  		inode->i_gid = current_fsgid();
314  
315  	inode->i_blocks = 0;
316  	inode->i_generation = 0;
317  	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
318  	ufsi->i_flags = UFS_I(dir)->i_flags;
319  	ufsi->i_lastfrag = 0;
320  	ufsi->i_shadow = 0;
321  	ufsi->i_osync = 0;
322  	ufsi->i_oeftflag = 0;
323  	ufsi->i_dir_start_lookup = 0;
324  	memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
325  	insert_inode_hash(inode);
326  	mark_inode_dirty(inode);
327  
328  	if (uspi->fs_magic == UFS2_MAGIC) {
329  		struct buffer_head *bh;
330  		struct ufs2_inode *ufs2_inode;
331  
332  		/*
333  		 * setup birth date, we do it here because of there is no sense
334  		 * to hold it in struct ufs_inode_info, and lose 64 bit
335  		 */
336  		bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
337  		if (!bh) {
338  			ufs_warning(sb, "ufs_read_inode",
339  				    "unable to read inode %lu\n",
340  				    inode->i_ino);
341  			err = -EIO;
342  			goto fail_remove_inode;
343  		}
344  		lock_buffer(bh);
345  		ufs2_inode = (struct ufs2_inode *)bh->b_data;
346  		ufs2_inode += ufs_inotofsbo(inode->i_ino);
347  		ufs2_inode->ui_birthtime = cpu_to_fs64(sb, CURRENT_TIME.tv_sec);
348  		ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, CURRENT_TIME.tv_nsec);
349  		mark_buffer_dirty(bh);
350  		unlock_buffer(bh);
351  		if (sb->s_flags & MS_SYNCHRONOUS)
352  			sync_dirty_buffer(bh);
353  		brelse(bh);
354  	}
355  
356  	unlock_super (sb);
357  
358  	if (vfs_dq_alloc_inode(inode)) {
359  		vfs_dq_drop(inode);
360  		err = -EDQUOT;
361  		goto fail_without_unlock;
362  	}
363  
364  	UFSD("allocating inode %lu\n", inode->i_ino);
365  	UFSD("EXIT\n");
366  	return inode;
367  
368  fail_remove_inode:
369  	unlock_super(sb);
370  fail_without_unlock:
371  	inode->i_flags |= S_NOQUOTA;
372  	inode->i_nlink = 0;
373  	iput(inode);
374  	UFSD("EXIT (FAILED): err %d\n", err);
375  	return ERR_PTR(err);
376  failed:
377  	unlock_super (sb);
378  	make_bad_inode(inode);
379  	iput (inode);
380  	UFSD("EXIT (FAILED): err %d\n", err);
381  	return ERR_PTR(err);
382  }
383