1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0
21da177e4SLinus Torvalds /*
31da177e4SLinus Torvalds * linux/fs/sysv/ialloc.c
41da177e4SLinus Torvalds *
51da177e4SLinus Torvalds * minix/bitmap.c
61da177e4SLinus Torvalds * Copyright (C) 1991, 1992 Linus Torvalds
71da177e4SLinus Torvalds *
81da177e4SLinus Torvalds * ext/freelists.c
91da177e4SLinus Torvalds * Copyright (C) 1992 Remy Card (card@masi.ibp.fr)
101da177e4SLinus Torvalds *
111da177e4SLinus Torvalds * xenix/alloc.c
121da177e4SLinus Torvalds * Copyright (C) 1992 Doug Evans
131da177e4SLinus Torvalds *
141da177e4SLinus Torvalds * coh/alloc.c
151da177e4SLinus Torvalds * Copyright (C) 1993 Pascal Haible, Bruno Haible
161da177e4SLinus Torvalds *
171da177e4SLinus Torvalds * sysv/ialloc.c
181da177e4SLinus Torvalds * Copyright (C) 1993 Bruno Haible
191da177e4SLinus Torvalds *
201da177e4SLinus Torvalds * This file contains code for allocating/freeing inodes.
211da177e4SLinus Torvalds */
221da177e4SLinus Torvalds
231da177e4SLinus Torvalds #include <linux/kernel.h>
241da177e4SLinus Torvalds #include <linux/stddef.h>
251da177e4SLinus Torvalds #include <linux/sched.h>
261da177e4SLinus Torvalds #include <linux/stat.h>
271da177e4SLinus Torvalds #include <linux/string.h>
281da177e4SLinus Torvalds #include <linux/buffer_head.h>
2946c23d7fSLubomir Rintel #include <linux/writeback.h>
301da177e4SLinus Torvalds #include "sysv.h"
311da177e4SLinus Torvalds
321da177e4SLinus Torvalds /* We don't trust the value of
331da177e4SLinus Torvalds sb->sv_sbd2->s_tinode = *sb->sv_sb_total_free_inodes
341da177e4SLinus Torvalds but we nevertheless keep it up to date. */
351da177e4SLinus Torvalds
361da177e4SLinus Torvalds /* An inode on disk is considered free if both i_mode == 0 and i_nlink == 0. */
371da177e4SLinus Torvalds
381da177e4SLinus Torvalds /* return &sb->sv_sb_fic_inodes[i] = &sbd->s_inode[i]; */
391da177e4SLinus Torvalds static inline sysv_ino_t *
sv_sb_fic_inode(struct super_block * sb,unsigned int i)401da177e4SLinus Torvalds sv_sb_fic_inode(struct super_block * sb, unsigned int i)
411da177e4SLinus Torvalds {
421da177e4SLinus Torvalds struct sysv_sb_info *sbi = SYSV_SB(sb);
431da177e4SLinus Torvalds
441da177e4SLinus Torvalds if (sbi->s_bh1 == sbi->s_bh2)
451da177e4SLinus Torvalds return &sbi->s_sb_fic_inodes[i];
461da177e4SLinus Torvalds else {
471da177e4SLinus Torvalds /* 512 byte Xenix FS */
481da177e4SLinus Torvalds unsigned int offset = offsetof(struct xenix_super_block, s_inode[i]);
491da177e4SLinus Torvalds if (offset < 512)
501da177e4SLinus Torvalds return (sysv_ino_t*)(sbi->s_sbd1 + offset);
511da177e4SLinus Torvalds else
521da177e4SLinus Torvalds return (sysv_ino_t*)(sbi->s_sbd2 + offset);
531da177e4SLinus Torvalds }
541da177e4SLinus Torvalds }
551da177e4SLinus Torvalds
561da177e4SLinus Torvalds struct sysv_inode *
sysv_raw_inode(struct super_block * sb,unsigned ino,struct buffer_head ** bh)571da177e4SLinus Torvalds sysv_raw_inode(struct super_block *sb, unsigned ino, struct buffer_head **bh)
581da177e4SLinus Torvalds {
591da177e4SLinus Torvalds struct sysv_sb_info *sbi = SYSV_SB(sb);
601da177e4SLinus Torvalds struct sysv_inode *res;
611da177e4SLinus Torvalds int block = sbi->s_firstinodezone + sbi->s_block_base;
621da177e4SLinus Torvalds
631da177e4SLinus Torvalds block += (ino-1) >> sbi->s_inodes_per_block_bits;
641da177e4SLinus Torvalds *bh = sb_bread(sb, block);
651da177e4SLinus Torvalds if (!*bh)
661da177e4SLinus Torvalds return NULL;
671da177e4SLinus Torvalds res = (struct sysv_inode *)(*bh)->b_data;
681da177e4SLinus Torvalds return res + ((ino-1) & sbi->s_inodes_per_block_1);
691da177e4SLinus Torvalds }
701da177e4SLinus Torvalds
refill_free_cache(struct super_block * sb)711da177e4SLinus Torvalds static int refill_free_cache(struct super_block *sb)
721da177e4SLinus Torvalds {
731da177e4SLinus Torvalds struct sysv_sb_info *sbi = SYSV_SB(sb);
741da177e4SLinus Torvalds struct buffer_head * bh;
751da177e4SLinus Torvalds struct sysv_inode * raw_inode;
761da177e4SLinus Torvalds int i = 0, ino;
771da177e4SLinus Torvalds
781da177e4SLinus Torvalds ino = SYSV_ROOT_INO+1;
791da177e4SLinus Torvalds raw_inode = sysv_raw_inode(sb, ino, &bh);
801da177e4SLinus Torvalds if (!raw_inode)
811da177e4SLinus Torvalds goto out;
821da177e4SLinus Torvalds while (ino <= sbi->s_ninodes) {
831da177e4SLinus Torvalds if (raw_inode->i_mode == 0 && raw_inode->i_nlink == 0) {
841da177e4SLinus Torvalds *sv_sb_fic_inode(sb,i++) = cpu_to_fs16(SYSV_SB(sb), ino);
851da177e4SLinus Torvalds if (i == sbi->s_fic_size)
861da177e4SLinus Torvalds break;
871da177e4SLinus Torvalds }
881da177e4SLinus Torvalds if ((ino++ & sbi->s_inodes_per_block_1) == 0) {
891da177e4SLinus Torvalds brelse(bh);
901da177e4SLinus Torvalds raw_inode = sysv_raw_inode(sb, ino, &bh);
911da177e4SLinus Torvalds if (!raw_inode)
921da177e4SLinus Torvalds goto out;
931da177e4SLinus Torvalds } else
941da177e4SLinus Torvalds raw_inode++;
951da177e4SLinus Torvalds }
961da177e4SLinus Torvalds brelse(bh);
971da177e4SLinus Torvalds out:
981da177e4SLinus Torvalds return i;
991da177e4SLinus Torvalds }
1001da177e4SLinus Torvalds
sysv_free_inode(struct inode * inode)1011da177e4SLinus Torvalds void sysv_free_inode(struct inode * inode)
1021da177e4SLinus Torvalds {
1031da177e4SLinus Torvalds struct super_block *sb = inode->i_sb;
1041da177e4SLinus Torvalds struct sysv_sb_info *sbi = SYSV_SB(sb);
1051da177e4SLinus Torvalds unsigned int ino;
1061da177e4SLinus Torvalds struct buffer_head * bh;
1071da177e4SLinus Torvalds struct sysv_inode * raw_inode;
1081da177e4SLinus Torvalds unsigned count;
1091da177e4SLinus Torvalds
1101da177e4SLinus Torvalds sb = inode->i_sb;
1111da177e4SLinus Torvalds ino = inode->i_ino;
1121da177e4SLinus Torvalds if (ino <= SYSV_ROOT_INO || ino > sbi->s_ninodes) {
1131da177e4SLinus Torvalds printk("sysv_free_inode: inode 0,1,2 or nonexistent inode\n");
1141da177e4SLinus Torvalds return;
1151da177e4SLinus Torvalds }
1161da177e4SLinus Torvalds raw_inode = sysv_raw_inode(sb, ino, &bh);
1171da177e4SLinus Torvalds if (!raw_inode) {
1181da177e4SLinus Torvalds printk("sysv_free_inode: unable to read inode block on device "
1191da177e4SLinus Torvalds "%s\n", inode->i_sb->s_id);
1201da177e4SLinus Torvalds return;
1211da177e4SLinus Torvalds }
122c07cb01cSMarco Stornelli mutex_lock(&sbi->s_lock);
1231da177e4SLinus Torvalds count = fs16_to_cpu(sbi, *sbi->s_sb_fic_count);
1241da177e4SLinus Torvalds if (count < sbi->s_fic_size) {
1251da177e4SLinus Torvalds *sv_sb_fic_inode(sb,count++) = cpu_to_fs16(sbi, ino);
1261da177e4SLinus Torvalds *sbi->s_sb_fic_count = cpu_to_fs16(sbi, count);
1271da177e4SLinus Torvalds }
1281da177e4SLinus Torvalds fs16_add(sbi, sbi->s_sb_total_free_inodes, 1);
1291da177e4SLinus Torvalds dirty_sb(sb);
1301da177e4SLinus Torvalds memset(raw_inode, 0, sizeof(struct sysv_inode));
1311da177e4SLinus Torvalds mark_buffer_dirty(bh);
132c07cb01cSMarco Stornelli mutex_unlock(&sbi->s_lock);
1331da177e4SLinus Torvalds brelse(bh);
1341da177e4SLinus Torvalds }
1351da177e4SLinus Torvalds
sysv_new_inode(const struct inode * dir,umode_t mode)136dd716e64SAl Viro struct inode * sysv_new_inode(const struct inode * dir, umode_t mode)
1371da177e4SLinus Torvalds {
1381da177e4SLinus Torvalds struct super_block *sb = dir->i_sb;
1391da177e4SLinus Torvalds struct sysv_sb_info *sbi = SYSV_SB(sb);
1401da177e4SLinus Torvalds struct inode *inode;
1411da177e4SLinus Torvalds sysv_ino_t ino;
1421da177e4SLinus Torvalds unsigned count;
14346c23d7fSLubomir Rintel struct writeback_control wbc = {
14446c23d7fSLubomir Rintel .sync_mode = WB_SYNC_NONE
14546c23d7fSLubomir Rintel };
1461da177e4SLinus Torvalds
1471da177e4SLinus Torvalds inode = new_inode(sb);
1481da177e4SLinus Torvalds if (!inode)
1491da177e4SLinus Torvalds return ERR_PTR(-ENOMEM);
1501da177e4SLinus Torvalds
151c07cb01cSMarco Stornelli mutex_lock(&sbi->s_lock);
1521da177e4SLinus Torvalds count = fs16_to_cpu(sbi, *sbi->s_sb_fic_count);
1531da177e4SLinus Torvalds if (count == 0 || (*sv_sb_fic_inode(sb,count-1) == 0)) {
1541da177e4SLinus Torvalds count = refill_free_cache(sb);
1551da177e4SLinus Torvalds if (count == 0) {
1561da177e4SLinus Torvalds iput(inode);
157c07cb01cSMarco Stornelli mutex_unlock(&sbi->s_lock);
1581da177e4SLinus Torvalds return ERR_PTR(-ENOSPC);
1591da177e4SLinus Torvalds }
1601da177e4SLinus Torvalds }
1611da177e4SLinus Torvalds /* Now count > 0. */
1621da177e4SLinus Torvalds ino = *sv_sb_fic_inode(sb,--count);
1631da177e4SLinus Torvalds *sbi->s_sb_fic_count = cpu_to_fs16(sbi, count);
1641da177e4SLinus Torvalds fs16_add(sbi, sbi->s_sb_total_free_inodes, -1);
1651da177e4SLinus Torvalds dirty_sb(sb);
166f2d40141SChristian Brauner inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
1671da177e4SLinus Torvalds inode->i_ino = fs16_to_cpu(sbi, ino);
168*c801b095SJeff Layton inode->i_mtime = inode->i_atime = inode_set_ctime_current(inode);
169ba52de12STheodore Ts'o inode->i_blocks = 0;
1701da177e4SLinus Torvalds memset(SYSV_I(inode)->i_data, 0, sizeof(SYSV_I(inode)->i_data));
1711da177e4SLinus Torvalds SYSV_I(inode)->i_dir_start_lookup = 0;
1721da177e4SLinus Torvalds insert_inode_hash(inode);
1731da177e4SLinus Torvalds mark_inode_dirty(inode);
1741da177e4SLinus Torvalds
17546c23d7fSLubomir Rintel sysv_write_inode(inode, &wbc); /* ensure inode not allocated again */
1761da177e4SLinus Torvalds mark_inode_dirty(inode); /* cleared by sysv_write_inode() */
1771da177e4SLinus Torvalds /* That's it. */
178c07cb01cSMarco Stornelli mutex_unlock(&sbi->s_lock);
1791da177e4SLinus Torvalds return inode;
1801da177e4SLinus Torvalds }
1811da177e4SLinus Torvalds
sysv_count_free_inodes(struct super_block * sb)1821da177e4SLinus Torvalds unsigned long sysv_count_free_inodes(struct super_block * sb)
1831da177e4SLinus Torvalds {
1841da177e4SLinus Torvalds struct sysv_sb_info *sbi = SYSV_SB(sb);
1851da177e4SLinus Torvalds struct buffer_head * bh;
1861da177e4SLinus Torvalds struct sysv_inode * raw_inode;
1871da177e4SLinus Torvalds int ino, count, sb_count;
1881da177e4SLinus Torvalds
189c07cb01cSMarco Stornelli mutex_lock(&sbi->s_lock);
1901da177e4SLinus Torvalds
1911da177e4SLinus Torvalds sb_count = fs16_to_cpu(sbi, *sbi->s_sb_total_free_inodes);
1921da177e4SLinus Torvalds
1931da177e4SLinus Torvalds if (0)
1941da177e4SLinus Torvalds goto trust_sb;
1951da177e4SLinus Torvalds
1961da177e4SLinus Torvalds /* this causes a lot of disk traffic ... */
1971da177e4SLinus Torvalds count = 0;
1981da177e4SLinus Torvalds ino = SYSV_ROOT_INO+1;
1991da177e4SLinus Torvalds raw_inode = sysv_raw_inode(sb, ino, &bh);
2001da177e4SLinus Torvalds if (!raw_inode)
2011da177e4SLinus Torvalds goto Eio;
2021da177e4SLinus Torvalds while (ino <= sbi->s_ninodes) {
2031da177e4SLinus Torvalds if (raw_inode->i_mode == 0 && raw_inode->i_nlink == 0)
2041da177e4SLinus Torvalds count++;
2051da177e4SLinus Torvalds if ((ino++ & sbi->s_inodes_per_block_1) == 0) {
2061da177e4SLinus Torvalds brelse(bh);
2071da177e4SLinus Torvalds raw_inode = sysv_raw_inode(sb, ino, &bh);
2081da177e4SLinus Torvalds if (!raw_inode)
2091da177e4SLinus Torvalds goto Eio;
2101da177e4SLinus Torvalds } else
2111da177e4SLinus Torvalds raw_inode++;
2121da177e4SLinus Torvalds }
2131da177e4SLinus Torvalds brelse(bh);
2141da177e4SLinus Torvalds if (count != sb_count)
2151da177e4SLinus Torvalds goto Einval;
2161da177e4SLinus Torvalds out:
217c07cb01cSMarco Stornelli mutex_unlock(&sbi->s_lock);
2181da177e4SLinus Torvalds return count;
2191da177e4SLinus Torvalds
2201da177e4SLinus Torvalds Einval:
2211da177e4SLinus Torvalds printk("sysv_count_free_inodes: "
2221da177e4SLinus Torvalds "free inode count was %d, correcting to %d\n",
2231da177e4SLinus Torvalds sb_count, count);
224bc98a42cSDavid Howells if (!sb_rdonly(sb)) {
2251da177e4SLinus Torvalds *sbi->s_sb_total_free_inodes = cpu_to_fs16(SYSV_SB(sb), count);
2261da177e4SLinus Torvalds dirty_sb(sb);
2271da177e4SLinus Torvalds }
2281da177e4SLinus Torvalds goto out;
2291da177e4SLinus Torvalds
2301da177e4SLinus Torvalds Eio:
2311da177e4SLinus Torvalds printk("sysv_count_free_inodes: unable to read inode table\n");
2321da177e4SLinus Torvalds trust_sb:
2331da177e4SLinus Torvalds count = sb_count;
2341da177e4SLinus Torvalds goto out;
2351da177e4SLinus Torvalds }
236