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![Arnd Bergmann](/assets/img/avatar_default.png)
get_seconds() is deprecated in favor of ktime_get_real_seconds(), which returns a 64-bit timestamp. In the SYSV file system, the superblock timestamp is only 32 bits wide, and it is used to check whether a file system is clean, so the best solution seems to be to force a wraparound and explicitly convert it to an unsigned 32-bit value. This is independent of the inode timestamps that are also 32-bit wide on disk and that come from current_time(). Link: http://lkml.kernel.org/r/20180713145236.3152513-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
364 lines
9.3 KiB
C
364 lines
9.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/sysv/inode.c
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*
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* minix/inode.c
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* xenix/inode.c
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* Copyright (C) 1992 Doug Evans
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*
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* coh/inode.c
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* Copyright (C) 1993 Pascal Haible, Bruno Haible
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*
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* sysv/inode.c
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* Copyright (C) 1993 Paul B. Monday
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*
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* sysv/inode.c
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* Copyright (C) 1993 Bruno Haible
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* Copyright (C) 1997, 1998 Krzysztof G. Baranowski
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*
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* This file contains code for allocating/freeing inodes and for read/writing
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* the superblock.
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*/
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#include <linux/highuid.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/buffer_head.h>
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#include <linux/vfs.h>
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#include <linux/writeback.h>
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#include <linux/namei.h>
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#include <asm/byteorder.h>
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#include "sysv.h"
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static int sysv_sync_fs(struct super_block *sb, int wait)
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{
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struct sysv_sb_info *sbi = SYSV_SB(sb);
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u32 time = (u32)ktime_get_real_seconds(), old_time;
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mutex_lock(&sbi->s_lock);
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/*
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* If we are going to write out the super block,
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* then attach current time stamp.
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* But if the filesystem was marked clean, keep it clean.
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*/
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old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
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if (sbi->s_type == FSTYPE_SYSV4) {
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if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38u - old_time))
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*sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38u - time);
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*sbi->s_sb_time = cpu_to_fs32(sbi, time);
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mark_buffer_dirty(sbi->s_bh2);
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}
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mutex_unlock(&sbi->s_lock);
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return 0;
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}
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static int sysv_remount(struct super_block *sb, int *flags, char *data)
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{
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struct sysv_sb_info *sbi = SYSV_SB(sb);
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sync_filesystem(sb);
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if (sbi->s_forced_ro)
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*flags |= SB_RDONLY;
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return 0;
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}
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static void sysv_put_super(struct super_block *sb)
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{
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struct sysv_sb_info *sbi = SYSV_SB(sb);
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if (!sb_rdonly(sb)) {
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/* XXX ext2 also updates the state here */
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mark_buffer_dirty(sbi->s_bh1);
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if (sbi->s_bh1 != sbi->s_bh2)
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mark_buffer_dirty(sbi->s_bh2);
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}
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brelse(sbi->s_bh1);
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if (sbi->s_bh1 != sbi->s_bh2)
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brelse(sbi->s_bh2);
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kfree(sbi);
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}
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static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
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{
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struct super_block *sb = dentry->d_sb;
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struct sysv_sb_info *sbi = SYSV_SB(sb);
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u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
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buf->f_type = sb->s_magic;
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buf->f_bsize = sb->s_blocksize;
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buf->f_blocks = sbi->s_ndatazones;
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buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
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buf->f_files = sbi->s_ninodes;
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buf->f_ffree = sysv_count_free_inodes(sb);
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buf->f_namelen = SYSV_NAMELEN;
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buf->f_fsid.val[0] = (u32)id;
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buf->f_fsid.val[1] = (u32)(id >> 32);
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return 0;
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}
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/*
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* NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
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*/
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static inline void read3byte(struct sysv_sb_info *sbi,
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unsigned char * from, unsigned char * to)
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{
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if (sbi->s_bytesex == BYTESEX_PDP) {
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to[0] = from[0];
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to[1] = 0;
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to[2] = from[1];
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to[3] = from[2];
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} else if (sbi->s_bytesex == BYTESEX_LE) {
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to[0] = from[0];
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to[1] = from[1];
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to[2] = from[2];
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to[3] = 0;
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} else {
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to[0] = 0;
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to[1] = from[0];
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to[2] = from[1];
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to[3] = from[2];
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}
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}
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static inline void write3byte(struct sysv_sb_info *sbi,
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unsigned char * from, unsigned char * to)
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{
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if (sbi->s_bytesex == BYTESEX_PDP) {
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to[0] = from[0];
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to[1] = from[2];
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to[2] = from[3];
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} else if (sbi->s_bytesex == BYTESEX_LE) {
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to[0] = from[0];
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to[1] = from[1];
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to[2] = from[2];
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} else {
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to[0] = from[1];
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to[1] = from[2];
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to[2] = from[3];
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}
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}
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static const struct inode_operations sysv_symlink_inode_operations = {
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.get_link = page_get_link,
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.getattr = sysv_getattr,
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};
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void sysv_set_inode(struct inode *inode, dev_t rdev)
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{
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if (S_ISREG(inode->i_mode)) {
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inode->i_op = &sysv_file_inode_operations;
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inode->i_fop = &sysv_file_operations;
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inode->i_mapping->a_ops = &sysv_aops;
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} else if (S_ISDIR(inode->i_mode)) {
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inode->i_op = &sysv_dir_inode_operations;
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inode->i_fop = &sysv_dir_operations;
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inode->i_mapping->a_ops = &sysv_aops;
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} else if (S_ISLNK(inode->i_mode)) {
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inode->i_op = &sysv_symlink_inode_operations;
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inode_nohighmem(inode);
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inode->i_mapping->a_ops = &sysv_aops;
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} else
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init_special_inode(inode, inode->i_mode, rdev);
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}
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struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
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{
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struct sysv_sb_info * sbi = SYSV_SB(sb);
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struct buffer_head * bh;
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struct sysv_inode * raw_inode;
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struct sysv_inode_info * si;
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struct inode *inode;
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unsigned int block;
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if (!ino || ino > sbi->s_ninodes) {
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printk("Bad inode number on dev %s: %d is out of range\n",
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sb->s_id, ino);
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return ERR_PTR(-EIO);
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}
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inode = iget_locked(sb, ino);
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if (!inode)
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return ERR_PTR(-ENOMEM);
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if (!(inode->i_state & I_NEW))
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return inode;
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raw_inode = sysv_raw_inode(sb, ino, &bh);
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if (!raw_inode) {
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printk("Major problem: unable to read inode from dev %s\n",
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inode->i_sb->s_id);
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goto bad_inode;
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}
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/* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
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inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
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i_uid_write(inode, (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid));
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i_gid_write(inode, (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid));
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set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink));
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inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
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inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
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inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
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inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
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inode->i_ctime.tv_nsec = 0;
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inode->i_atime.tv_nsec = 0;
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inode->i_mtime.tv_nsec = 0;
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inode->i_blocks = 0;
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si = SYSV_I(inode);
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for (block = 0; block < 10+1+1+1; block++)
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read3byte(sbi, &raw_inode->i_data[3*block],
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(u8 *)&si->i_data[block]);
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brelse(bh);
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si->i_dir_start_lookup = 0;
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if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
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sysv_set_inode(inode,
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old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
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else
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sysv_set_inode(inode, 0);
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unlock_new_inode(inode);
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return inode;
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bad_inode:
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iget_failed(inode);
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return ERR_PTR(-EIO);
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}
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static int __sysv_write_inode(struct inode *inode, int wait)
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{
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struct super_block * sb = inode->i_sb;
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struct sysv_sb_info * sbi = SYSV_SB(sb);
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struct buffer_head * bh;
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struct sysv_inode * raw_inode;
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struct sysv_inode_info * si;
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unsigned int ino, block;
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int err = 0;
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ino = inode->i_ino;
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if (!ino || ino > sbi->s_ninodes) {
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printk("Bad inode number on dev %s: %d is out of range\n",
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inode->i_sb->s_id, ino);
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return -EIO;
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}
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raw_inode = sysv_raw_inode(sb, ino, &bh);
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if (!raw_inode) {
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printk("unable to read i-node block\n");
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return -EIO;
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}
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raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
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raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(i_uid_read(inode)));
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raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(i_gid_read(inode)));
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raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
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raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
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raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
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raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
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raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
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si = SYSV_I(inode);
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if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
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si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
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for (block = 0; block < 10+1+1+1; block++)
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write3byte(sbi, (u8 *)&si->i_data[block],
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&raw_inode->i_data[3*block]);
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mark_buffer_dirty(bh);
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if (wait) {
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sync_dirty_buffer(bh);
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if (buffer_req(bh) && !buffer_uptodate(bh)) {
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printk ("IO error syncing sysv inode [%s:%08x]\n",
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sb->s_id, ino);
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err = -EIO;
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}
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}
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brelse(bh);
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return 0;
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}
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int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
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{
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return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
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}
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int sysv_sync_inode(struct inode *inode)
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{
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return __sysv_write_inode(inode, 1);
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}
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static void sysv_evict_inode(struct inode *inode)
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{
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truncate_inode_pages_final(&inode->i_data);
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if (!inode->i_nlink) {
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inode->i_size = 0;
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sysv_truncate(inode);
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}
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invalidate_inode_buffers(inode);
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clear_inode(inode);
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if (!inode->i_nlink)
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sysv_free_inode(inode);
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}
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static struct kmem_cache *sysv_inode_cachep;
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static struct inode *sysv_alloc_inode(struct super_block *sb)
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{
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struct sysv_inode_info *si;
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si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
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if (!si)
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return NULL;
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return &si->vfs_inode;
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}
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static void sysv_i_callback(struct rcu_head *head)
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{
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struct inode *inode = container_of(head, struct inode, i_rcu);
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kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
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}
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static void sysv_destroy_inode(struct inode *inode)
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{
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call_rcu(&inode->i_rcu, sysv_i_callback);
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}
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static void init_once(void *p)
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{
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struct sysv_inode_info *si = (struct sysv_inode_info *)p;
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inode_init_once(&si->vfs_inode);
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}
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const struct super_operations sysv_sops = {
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.alloc_inode = sysv_alloc_inode,
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.destroy_inode = sysv_destroy_inode,
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.write_inode = sysv_write_inode,
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.evict_inode = sysv_evict_inode,
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.put_super = sysv_put_super,
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.sync_fs = sysv_sync_fs,
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.remount_fs = sysv_remount,
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.statfs = sysv_statfs,
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};
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int __init sysv_init_icache(void)
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{
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sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
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sizeof(struct sysv_inode_info), 0,
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SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_ACCOUNT,
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init_once);
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if (!sysv_inode_cachep)
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return -ENOMEM;
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return 0;
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}
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void sysv_destroy_icache(void)
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{
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/*
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* Make sure all delayed rcu free inodes are flushed before we
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* destroy cache.
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*/
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rcu_barrier();
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kmem_cache_destroy(sysv_inode_cachep);
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}
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