fs/ufs/ialloc.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  *  linux/fs/ufs/ialloc.c
0004  *
0005  * Copyright (c) 1998
0006  * Daniel Pirkl <daniel.pirkl@email.cz>
0007  * Charles University, Faculty of Mathematics and Physics
0008  *
0009  *  from
0010  *
0011  *  linux/fs/ext2/ialloc.c
0012  *
0013  * Copyright (C) 1992, 1993, 1994, 1995
0014  * Remy Card (card@masi.ibp.fr)
0015  * Laboratoire MASI - Institut Blaise Pascal
0016  * Universite Pierre et Marie Curie (Paris VI)
0017  *
0018  *  BSD ufs-inspired inode and directory allocation by
0019  *  Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
0020  *  Big-endian to little-endian byte-swapping/bitmaps by
0021  *        David S. Miller (davem@caip.rutgers.edu), 1995
0022  *
0023  * UFS2 write support added by
0024  * Evgeniy Dushistov <dushistov@mail.ru>, 2007
0025  */
0026
0027 #include <linux/fs.h>
0028 #include <linux/time.h>
0029 #include <linux/stat.h>
0030 #include <linux/string.h>
0031 #include <linux/buffer_head.h>
0032 #include <linux/sched.h>
0033 #include <linux/bitops.h>
0034 #include <asm/byteorder.h>
0035
0036 #include "ufs_fs.h"
0037 #include "ufs.h"
0038 #include "swab.h"
0039 #include "util.h"
0040
0041 /*
0042  * NOTE! When we get the inode, we're the only people
0043  * that have access to it, and as such there are no
0044  * race conditions we have to worry about. The inode
0045  * is not on the hash-lists, and it cannot be reached
0046  * through the filesystem because the directory entry
0047  * has been deleted earlier.
0048  *
0049  * HOWEVER: we must make sure that we get no aliases,
0050  * which means that we have to call "clear_inode()"
0051  * _before_ we mark the inode not in use in the inode
0052  * bitmaps. Otherwise a newly created file might use
0053  * the same inode number (not actually the same pointer
0054  * though), and then we'd have two inodes sharing the
0055  * same inode number and space on the harddisk.
0056  */
0057 void ufs_free_inode (struct inode * inode)
0058 {
0059     struct super_block * sb;
0060     struct ufs_sb_private_info * uspi;
0061     struct ufs_cg_private_info * ucpi;
0062     struct ufs_cylinder_group * ucg;
0063     int is_directory;
0064     unsigned ino, cg, bit;
0065
0066     UFSD("ENTER, ino %lu\n", inode->i_ino);
0067
0068     sb = inode->i_sb;
0069     uspi = UFS_SB(sb)->s_uspi;
0070
0071     ino = inode->i_ino;
0072
0073     mutex_lock(&UFS_SB(sb)->s_lock);
0074
0075     if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
0076         ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
0077         mutex_unlock(&UFS_SB(sb)->s_lock);
0078         return;
0079     }
0080
0081     cg = ufs_inotocg (ino);
0082     bit = ufs_inotocgoff (ino);
0083     ucpi = ufs_load_cylinder (sb, cg);
0084     if (!ucpi) {
0085         mutex_unlock(&UFS_SB(sb)->s_lock);
0086         return;
0087     }
0088     ucg = ubh_get_ucg(UCPI_UBH(ucpi));
0089     if (!ufs_cg_chkmagic(sb, ucg))
0090         ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
0091
0092     ucg->cg_time = ufs_get_seconds(sb);
0093
0094     is_directory = S_ISDIR(inode->i_mode);
0095
0096     if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
0097         ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
0098     else {
0099         ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
0100         if (ino < ucpi->c_irotor)
0101             ucpi->c_irotor = ino;
0102         fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
0103         uspi->cs_total.cs_nifree++;
0104         fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
0105
0106         if (is_directory) {
0107             fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
0108             uspi->cs_total.cs_ndir--;
0109             fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
0110         }
0111     }
0112
0113     ubh_mark_buffer_dirty (USPI_UBH(uspi));
0114     ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
0115     if (sb->s_flags & SB_SYNCHRONOUS)
0116         ubh_sync_block(UCPI_UBH(ucpi));
0117
0118     ufs_mark_sb_dirty(sb);
0119     mutex_unlock(&UFS_SB(sb)->s_lock);
0120     UFSD("EXIT\n");
0121 }
0122
0123 /*
0124  * Nullify new chunk of inodes,
0125  * BSD people also set ui_gen field of inode
0126  * during nullification, but we not care about
0127  * that because of linux ufs do not support NFS
0128  */
0129 static void ufs2_init_inodes_chunk(struct super_block *sb,
0130                    struct ufs_cg_private_info *ucpi,
0131                    struct ufs_cylinder_group *ucg)
0132 {
0133     struct buffer_head *bh;
0134     struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
0135     sector_t beg = uspi->s_sbbase +
0136         ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg +
0137                   fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk));
0138     sector_t end = beg + uspi->s_fpb;
0139
0140     UFSD("ENTER cgno %d\n", ucpi->c_cgx);
0141
0142     for (; beg < end; ++beg) {
0143         bh = sb_getblk(sb, beg);
0144         lock_buffer(bh);
0145         memset(bh->b_data, 0, sb->s_blocksize);
0146         set_buffer_uptodate(bh);
0147         mark_buffer_dirty(bh);
0148         unlock_buffer(bh);
0149         if (sb->s_flags & SB_SYNCHRONOUS)
0150             sync_dirty_buffer(bh);
0151         brelse(bh);
0152     }
0153
0154     fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb);
0155     ubh_mark_buffer_dirty(UCPI_UBH(ucpi));
0156     if (sb->s_flags & SB_SYNCHRONOUS)
0157         ubh_sync_block(UCPI_UBH(ucpi));
0158
0159     UFSD("EXIT\n");
0160 }
0161
0162 /*
0163  * There are two policies for allocating an inode.  If the new inode is
0164  * a directory, then a forward search is made for a block group with both
0165  * free space and a low directory-to-inode ratio; if that fails, then of
0166  * the groups with above-average free space, that group with the fewest
0167  * directories already is chosen.
0168  *
0169  * For other inodes, search forward from the parent directory's block
0170  * group to find a free inode.
0171  */
0172 struct inode *ufs_new_inode(struct inode *dir, umode_t mode)
0173 {
0174     struct super_block * sb;
0175     struct ufs_sb_info * sbi;
0176     struct ufs_sb_private_info * uspi;
0177     struct ufs_cg_private_info * ucpi;
0178     struct ufs_cylinder_group * ucg;
0179     struct inode * inode;
0180     struct timespec64 ts;
0181     unsigned cg, bit, i, j, start;
0182     struct ufs_inode_info *ufsi;
0183     int err = -ENOSPC;
0184
0185     UFSD("ENTER\n");
0186
0187     /* Cannot create files in a deleted directory */
0188     if (!dir || !dir->i_nlink)
0189         return ERR_PTR(-EPERM);
0190     sb = dir->i_sb;
0191     inode = new_inode(sb);
0192     if (!inode)
0193         return ERR_PTR(-ENOMEM);
0194     ufsi = UFS_I(inode);
0195     sbi = UFS_SB(sb);
0196     uspi = sbi->s_uspi;
0197
0198     mutex_lock(&sbi->s_lock);
0199
0200     /*
0201      * Try to place the inode in its parent directory
0202      */
0203     i = ufs_inotocg(dir->i_ino);
0204     if (sbi->fs_cs(i).cs_nifree) {
0205         cg = i;
0206         goto cg_found;
0207     }
0208
0209     /*
0210      * Use a quadratic hash to find a group with a free inode
0211      */
0212     for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
0213         i += j;
0214         if (i >= uspi->s_ncg)
0215             i -= uspi->s_ncg;
0216         if (sbi->fs_cs(i).cs_nifree) {
0217             cg = i;
0218             goto cg_found;
0219         }
0220     }
0221
0222     /*
0223      * That failed: try linear search for a free inode
0224      */
0225     i = ufs_inotocg(dir->i_ino) + 1;
0226     for (j = 2; j < uspi->s_ncg; j++) {
0227         i++;
0228         if (i >= uspi->s_ncg)
0229             i = 0;
0230         if (sbi->fs_cs(i).cs_nifree) {
0231             cg = i;
0232             goto cg_found;
0233         }
0234     }
0235
0236     goto failed;
0237
0238 cg_found:
0239     ucpi = ufs_load_cylinder (sb, cg);
0240     if (!ucpi) {
0241         err = -EIO;
0242         goto failed;
0243     }
0244     ucg = ubh_get_ucg(UCPI_UBH(ucpi));
0245     if (!ufs_cg_chkmagic(sb, ucg))
0246         ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
0247
0248     start = ucpi->c_irotor;
0249     bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
0250     if (!(bit < uspi->s_ipg)) {
0251         bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
0252         if (!(bit < start)) {
0253             ufs_error (sb, "ufs_new_inode",
0254                 "cylinder group %u corrupted - error in inode bitmap\n", cg);
0255             err = -EIO;
0256             goto failed;
0257         }
0258     }
0259     UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
0260     if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
0261         ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
0262     else {
0263         ufs_panic (sb, "ufs_new_inode", "internal error");
0264         err = -EIO;
0265         goto failed;
0266     }
0267
0268     if (uspi->fs_magic == UFS2_MAGIC) {
0269         u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk);
0270
0271         if (bit + uspi->s_inopb > initediblk &&
0272             initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk))
0273             ufs2_init_inodes_chunk(sb, ucpi, ucg);
0274     }
0275
0276     fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
0277     uspi->cs_total.cs_nifree--;
0278     fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
0279
0280     if (S_ISDIR(mode)) {
0281         fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
0282         uspi->cs_total.cs_ndir++;
0283         fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
0284     }
0285     ubh_mark_buffer_dirty (USPI_UBH(uspi));
0286     ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
0287     if (sb->s_flags & SB_SYNCHRONOUS)
0288         ubh_sync_block(UCPI_UBH(ucpi));
0289     ufs_mark_sb_dirty(sb);
0290
0291     inode->i_ino = cg * uspi->s_ipg + bit;
0292     inode_init_owner(&init_user_ns, inode, dir, mode);
0293     inode->i_blocks = 0;
0294     inode->i_generation = 0;
0295     inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
0296     ufsi->i_flags = UFS_I(dir)->i_flags;
0297     ufsi->i_lastfrag = 0;
0298     ufsi->i_shadow = 0;
0299     ufsi->i_osync = 0;
0300     ufsi->i_oeftflag = 0;
0301     ufsi->i_dir_start_lookup = 0;
0302     memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
0303     if (insert_inode_locked(inode) < 0) {
0304         err = -EIO;
0305         goto failed;
0306     }
0307     mark_inode_dirty(inode);
0308
0309     if (uspi->fs_magic == UFS2_MAGIC) {
0310         struct buffer_head *bh;
0311         struct ufs2_inode *ufs2_inode;
0312
0313         /*
0314          * setup birth date, we do it here because of there is no sense
0315          * to hold it in struct ufs_inode_info, and lose 64 bit
0316          */
0317         bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
0318         if (!bh) {
0319             ufs_warning(sb, "ufs_read_inode",
0320                     "unable to read inode %lu\n",
0321                     inode->i_ino);
0322             err = -EIO;
0323             goto fail_remove_inode;
0324         }
0325         lock_buffer(bh);
0326         ufs2_inode = (struct ufs2_inode *)bh->b_data;
0327         ufs2_inode += ufs_inotofsbo(inode->i_ino);
0328         ktime_get_real_ts64(&ts);
0329         ufs2_inode->ui_birthtime = cpu_to_fs64(sb, ts.tv_sec);
0330         ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, ts.tv_nsec);
0331         mark_buffer_dirty(bh);
0332         unlock_buffer(bh);
0333         if (sb->s_flags & SB_SYNCHRONOUS)
0334             sync_dirty_buffer(bh);
0335         brelse(bh);
0336     }
0337     mutex_unlock(&sbi->s_lock);
0338
0339     UFSD("allocating inode %lu\n", inode->i_ino);
0340     UFSD("EXIT\n");
0341     return inode;
0342
0343 fail_remove_inode:
0344     mutex_unlock(&sbi->s_lock);
0345     clear_nlink(inode);
0346     discard_new_inode(inode);
0347     UFSD("EXIT (FAILED): err %d\n", err);
0348     return ERR_PTR(err);
0349 failed:
0350     mutex_unlock(&sbi->s_lock);
0351     make_bad_inode(inode);
0352     iput (inode);
0353     UFSD("EXIT (FAILED): err %d\n", err);
0354     return ERR_PTR(err);
0355 }