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![Adrian Bunk](/assets/img/avatar_default.png)
Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
212 lines
5.5 KiB
C
212 lines
5.5 KiB
C
/*
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* linux/fs/fat/misc.c
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*
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* Written 1992,1993 by Werner Almesberger
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* 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
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* and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
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*/
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/msdos_fs.h>
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#include <linux/buffer_head.h>
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/*
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* fat_fs_panic reports a severe file system problem and sets the file system
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* read-only. The file system can be made writable again by remounting it.
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*/
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void fat_fs_panic(struct super_block *s, const char *fmt, ...)
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{
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va_list args;
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printk(KERN_ERR "FAT: Filesystem panic (dev %s)\n", s->s_id);
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printk(KERN_ERR " ");
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va_start(args, fmt);
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vprintk(fmt, args);
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va_end(args);
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printk("\n");
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if (!(s->s_flags & MS_RDONLY)) {
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s->s_flags |= MS_RDONLY;
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printk(KERN_ERR " File system has been set read-only\n");
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}
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}
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EXPORT_SYMBOL_GPL(fat_fs_panic);
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/* Flushes the number of free clusters on FAT32 */
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/* XXX: Need to write one per FSINFO block. Currently only writes 1 */
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void fat_clusters_flush(struct super_block *sb)
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{
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struct msdos_sb_info *sbi = MSDOS_SB(sb);
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struct buffer_head *bh;
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struct fat_boot_fsinfo *fsinfo;
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if (sbi->fat_bits != 32)
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return;
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bh = sb_bread(sb, sbi->fsinfo_sector);
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if (bh == NULL) {
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printk(KERN_ERR "FAT: bread failed in fat_clusters_flush\n");
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return;
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}
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fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
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/* Sanity check */
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if (!IS_FSINFO(fsinfo)) {
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printk(KERN_ERR "FAT: Did not find valid FSINFO signature.\n"
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" Found signature1 0x%08x signature2 0x%08x"
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" (sector = %lu)\n",
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le32_to_cpu(fsinfo->signature1),
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le32_to_cpu(fsinfo->signature2),
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sbi->fsinfo_sector);
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} else {
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if (sbi->free_clusters != -1)
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fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters);
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if (sbi->prev_free != -1)
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fsinfo->next_cluster = cpu_to_le32(sbi->prev_free);
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mark_buffer_dirty(bh);
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}
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brelse(bh);
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}
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/*
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* fat_chain_add() adds a new cluster to the chain of clusters represented
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* by inode.
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*/
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int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
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{
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struct super_block *sb = inode->i_sb;
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struct msdos_sb_info *sbi = MSDOS_SB(sb);
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int ret, new_fclus, last;
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/*
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* We must locate the last cluster of the file to add this new
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* one (new_dclus) to the end of the link list (the FAT).
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*/
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last = new_fclus = 0;
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if (MSDOS_I(inode)->i_start) {
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int fclus, dclus;
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ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
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if (ret < 0)
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return ret;
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new_fclus = fclus + 1;
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last = dclus;
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}
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/* add new one to the last of the cluster chain */
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if (last) {
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struct fat_entry fatent;
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fatent_init(&fatent);
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ret = fat_ent_read(inode, &fatent, last);
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if (ret >= 0) {
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int wait = inode_needs_sync(inode);
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ret = fat_ent_write(inode, &fatent, new_dclus, wait);
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fatent_brelse(&fatent);
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}
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if (ret < 0)
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return ret;
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// fat_cache_add(inode, new_fclus, new_dclus);
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} else {
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MSDOS_I(inode)->i_start = new_dclus;
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MSDOS_I(inode)->i_logstart = new_dclus;
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/*
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* Since generic_osync_inode() synchronize later if
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* this is not directory, we don't here.
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*/
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if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
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ret = fat_sync_inode(inode);
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if (ret)
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return ret;
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} else
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mark_inode_dirty(inode);
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}
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if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
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fat_fs_panic(sb, "clusters badly computed (%d != %lu)",
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new_fclus, inode->i_blocks >> (sbi->cluster_bits - 9));
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fat_cache_inval_inode(inode);
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}
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inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
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return 0;
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}
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extern struct timezone sys_tz;
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/* Linear day numbers of the respective 1sts in non-leap years. */
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static int day_n[] = {
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/* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
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0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0, 0
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};
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/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */
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int date_dos2unix(unsigned short time, unsigned short date)
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{
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int month, year, secs;
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/*
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* first subtract and mask after that... Otherwise, if
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* date == 0, bad things happen
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*/
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month = ((date >> 5) - 1) & 15;
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year = date >> 9;
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secs = (time & 31)*2+60*((time >> 5) & 63)+(time >> 11)*3600+86400*
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((date & 31)-1+day_n[month]+(year/4)+year*365-((year & 3) == 0 &&
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month < 2 ? 1 : 0)+3653);
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/* days since 1.1.70 plus 80's leap day */
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secs += sys_tz.tz_minuteswest*60;
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return secs;
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}
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/* Convert linear UNIX date to a MS-DOS time/date pair. */
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void fat_date_unix2dos(int unix_date, __le16 *time, __le16 *date)
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{
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int day, year, nl_day, month;
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unix_date -= sys_tz.tz_minuteswest*60;
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/* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
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if (unix_date < 315532800)
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unix_date = 315532800;
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*time = cpu_to_le16((unix_date % 60)/2+(((unix_date/60) % 60) << 5)+
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(((unix_date/3600) % 24) << 11));
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day = unix_date/86400-3652;
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year = day/365;
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if ((year+3)/4+365*year > day)
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year--;
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day -= (year+3)/4+365*year;
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if (day == 59 && !(year & 3)) {
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nl_day = day;
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month = 2;
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} else {
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nl_day = (year & 3) || day <= 59 ? day : day-1;
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for (month = 0; month < 12; month++) {
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if (day_n[month] > nl_day)
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break;
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}
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}
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*date = cpu_to_le16(nl_day-day_n[month-1]+1+(month << 5)+(year << 9));
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}
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EXPORT_SYMBOL_GPL(fat_date_unix2dos);
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int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
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{
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int i, err = 0;
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ll_rw_block(SWRITE, nr_bhs, bhs);
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for (i = 0; i < nr_bhs; i++) {
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wait_on_buffer(bhs[i]);
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if (buffer_eopnotsupp(bhs[i])) {
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clear_buffer_eopnotsupp(bhs[i]);
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err = -EOPNOTSUPP;
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} else if (!err && !buffer_uptodate(bhs[i]))
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err = -EIO;
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}
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return err;
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}
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