forked from mirrors/linux
exfat: add file operations
This adds the implementation of file operations for exfat. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Reviewed-by: Pali Rohár <pali.rohar@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Namjae Jeon
Al Viro
parent
ca06197382
commit
98d917047e
1 changed files with 360 additions and 0 deletions
360
fs/exfat/file.c
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360
fs/exfat/file.c
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@ -0,0 +1,360 @@
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
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*/
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#include <linux/slab.h>
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#include <linux/cred.h>
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#include <linux/buffer_head.h>
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#include "exfat_raw.h"
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#include "exfat_fs.h"
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static int exfat_cont_expand(struct inode *inode, loff_t size)
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{
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struct address_space *mapping = inode->i_mapping;
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loff_t start = i_size_read(inode), count = size - i_size_read(inode);
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int err, err2;
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err = generic_cont_expand_simple(inode, size);
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if (err)
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return err;
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inode->i_ctime = inode->i_mtime = current_time(inode);
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mark_inode_dirty(inode);
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if (!IS_SYNC(inode))
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return 0;
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err = filemap_fdatawrite_range(mapping, start, start + count - 1);
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err2 = sync_mapping_buffers(mapping);
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if (!err)
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err = err2;
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err2 = write_inode_now(inode, 1);
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if (!err)
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err = err2;
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if (err)
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return err;
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return filemap_fdatawait_range(mapping, start, start + count - 1);
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}
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static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode)
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{
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mode_t allow_utime = sbi->options.allow_utime;
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if (!uid_eq(current_fsuid(), inode->i_uid)) {
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if (in_group_p(inode->i_gid))
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allow_utime >>= 3;
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if (allow_utime & MAY_WRITE)
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return true;
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}
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/* use a default check */
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return false;
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}
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static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
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struct inode *inode, umode_t *mode_ptr)
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{
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mode_t i_mode, mask, perm;
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i_mode = inode->i_mode;
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mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ?
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sbi->options.fs_fmask : sbi->options.fs_dmask;
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perm = *mode_ptr & ~(S_IFMT | mask);
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/* Of the r and x bits, all (subject to umask) must be present.*/
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if ((perm & 0555) != (i_mode & 0555))
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return -EPERM;
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if (exfat_mode_can_hold_ro(inode)) {
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/*
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* Of the w bits, either all (subject to umask) or none must
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* be present.
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*/
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if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
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return -EPERM;
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} else {
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/*
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* If exfat_mode_can_hold_ro(inode) is false, can't change
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* w bits.
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*/
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if ((perm & 0222) != (0222 & ~mask))
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return -EPERM;
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}
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*mode_ptr &= S_IFMT | perm;
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return 0;
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}
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/* resize the file length */
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int __exfat_truncate(struct inode *inode, loff_t new_size)
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{
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unsigned int num_clusters_new, num_clusters_phys;
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unsigned int last_clu = EXFAT_FREE_CLUSTER;
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struct exfat_chain clu;
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struct exfat_dentry *ep, *ep2;
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struct super_block *sb = inode->i_sb;
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struct exfat_sb_info *sbi = EXFAT_SB(sb);
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struct exfat_inode_info *ei = EXFAT_I(inode);
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struct exfat_entry_set_cache *es = NULL;
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int evict = (ei->dir.dir == DIR_DELETED) ? 1 : 0;
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/* check if the given file ID is opened */
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if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
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return -EPERM;
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exfat_set_vol_flags(sb, VOL_DIRTY);
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num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
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num_clusters_phys =
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EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk, sbi);
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exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
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if (new_size > 0) {
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/*
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* Truncate FAT chain num_clusters after the first cluster
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* num_clusters = min(new, phys);
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*/
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unsigned int num_clusters =
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min(num_clusters_new, num_clusters_phys);
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/*
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* Follow FAT chain
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* (defensive coding - works fine even with corrupted FAT table
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*/
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if (clu.flags == ALLOC_NO_FAT_CHAIN) {
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clu.dir += num_clusters;
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clu.size -= num_clusters;
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} else {
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while (num_clusters > 0) {
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last_clu = clu.dir;
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if (exfat_get_next_cluster(sb, &(clu.dir)))
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return -EIO;
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num_clusters--;
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clu.size--;
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}
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}
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} else {
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ei->flags = ALLOC_NO_FAT_CHAIN;
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ei->start_clu = EXFAT_EOF_CLUSTER;
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}
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i_size_write(inode, new_size);
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if (ei->type == TYPE_FILE)
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ei->attr |= ATTR_ARCHIVE;
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/* update the directory entry */
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if (!evict) {
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struct timespec64 ts;
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es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
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ES_ALL_ENTRIES, &ep);
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if (!es)
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return -EIO;
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ep2 = ep + 1;
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ts = current_time(inode);
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exfat_set_entry_time(sbi, &ts,
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&ep->dentry.file.modify_tz,
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&ep->dentry.file.modify_time,
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&ep->dentry.file.modify_date,
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&ep->dentry.file.modify_time_ms);
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ep->dentry.file.attr = cpu_to_le16(ei->attr);
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/* File size should be zero if there is no cluster allocated */
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if (ei->start_clu == EXFAT_EOF_CLUSTER) {
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ep->dentry.stream.valid_size = 0;
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ep->dentry.stream.size = 0;
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} else {
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ep->dentry.stream.valid_size = cpu_to_le64(new_size);
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ep->dentry.stream.size = ep->dentry.stream.valid_size;
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}
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if (new_size == 0) {
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/* Any directory can not be truncated to zero */
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WARN_ON(ei->type != TYPE_FILE);
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ep2->dentry.stream.flags = ALLOC_FAT_CHAIN;
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ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
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}
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if (exfat_update_dir_chksum_with_entry_set(sb, es,
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inode_needs_sync(inode)))
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return -EIO;
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kfree(es);
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}
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/* cut off from the FAT chain */
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if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
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last_clu != EXFAT_EOF_CLUSTER) {
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if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
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return -EIO;
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}
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/* invalidate cache and free the clusters */
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/* clear exfat cache */
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exfat_cache_inval_inode(inode);
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/* hint information */
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ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
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ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
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if (ei->rwoffset > new_size)
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ei->rwoffset = new_size;
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/* hint_stat will be used if this is directory. */
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ei->hint_stat.eidx = 0;
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ei->hint_stat.clu = ei->start_clu;
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ei->hint_femp.eidx = EXFAT_HINT_NONE;
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/* free the clusters */
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if (exfat_free_cluster(inode, &clu))
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return -EIO;
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exfat_set_vol_flags(sb, VOL_CLEAN);
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return 0;
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}
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void exfat_truncate(struct inode *inode, loff_t size)
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{
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struct super_block *sb = inode->i_sb;
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struct exfat_sb_info *sbi = EXFAT_SB(sb);
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unsigned int blocksize = 1 << inode->i_blkbits;
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loff_t aligned_size;
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int err;
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mutex_lock(&sbi->s_lock);
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if (EXFAT_I(inode)->start_clu == 0) {
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/*
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* Empty start_clu != ~0 (not allocated)
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*/
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exfat_fs_error(sb, "tried to truncate zeroed cluster.");
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goto write_size;
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}
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err = __exfat_truncate(inode, i_size_read(inode));
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if (err)
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goto write_size;
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inode->i_ctime = inode->i_mtime = current_time(inode);
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if (IS_DIRSYNC(inode))
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exfat_sync_inode(inode);
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else
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mark_inode_dirty(inode);
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inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1)) &
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~(sbi->cluster_size - 1)) >> inode->i_blkbits;
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write_size:
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aligned_size = i_size_read(inode);
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if (aligned_size & (blocksize - 1)) {
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aligned_size |= (blocksize - 1);
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aligned_size++;
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}
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if (EXFAT_I(inode)->i_size_ondisk > i_size_read(inode))
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EXFAT_I(inode)->i_size_ondisk = aligned_size;
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if (EXFAT_I(inode)->i_size_aligned > i_size_read(inode))
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EXFAT_I(inode)->i_size_aligned = aligned_size;
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mutex_unlock(&sbi->s_lock);
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}
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int exfat_getattr(const struct path *path, struct kstat *stat,
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unsigned int request_mask, unsigned int query_flags)
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{
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struct inode *inode = d_backing_inode(path->dentry);
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struct exfat_inode_info *ei = EXFAT_I(inode);
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generic_fillattr(inode, stat);
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stat->result_mask |= STATX_BTIME;
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stat->btime.tv_sec = ei->i_crtime.tv_sec;
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stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
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stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
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return 0;
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}
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int exfat_setattr(struct dentry *dentry, struct iattr *attr)
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{
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struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
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struct inode *inode = dentry->d_inode;
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unsigned int ia_valid;
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int error;
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if ((attr->ia_valid & ATTR_SIZE) &&
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attr->ia_size > i_size_read(inode)) {
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error = exfat_cont_expand(inode, attr->ia_size);
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if (error || attr->ia_valid == ATTR_SIZE)
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return error;
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attr->ia_valid &= ~ATTR_SIZE;
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}
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/* Check for setting the inode time. */
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ia_valid = attr->ia_valid;
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if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
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exfat_allow_set_time(sbi, inode)) {
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attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
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ATTR_TIMES_SET);
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}
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error = setattr_prepare(dentry, attr);
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attr->ia_valid = ia_valid;
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if (error)
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goto out;
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if (((attr->ia_valid & ATTR_UID) &&
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!uid_eq(attr->ia_uid, sbi->options.fs_uid)) ||
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((attr->ia_valid & ATTR_GID) &&
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!gid_eq(attr->ia_gid, sbi->options.fs_gid)) ||
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((attr->ia_valid & ATTR_MODE) &&
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(attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
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error = -EPERM;
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goto out;
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}
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/*
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* We don't return -EPERM here. Yes, strange, but this is too
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* old behavior.
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*/
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if (attr->ia_valid & ATTR_MODE) {
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if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
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attr->ia_valid &= ~ATTR_MODE;
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}
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if (attr->ia_valid & ATTR_SIZE) {
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error = exfat_block_truncate_page(inode, attr->ia_size);
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if (error)
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goto out;
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down_write(&EXFAT_I(inode)->truncate_lock);
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truncate_setsize(inode, attr->ia_size);
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exfat_truncate(inode, attr->ia_size);
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up_write(&EXFAT_I(inode)->truncate_lock);
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}
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setattr_copy(inode, attr);
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mark_inode_dirty(inode);
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out:
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return error;
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}
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const struct file_operations exfat_file_operations = {
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.llseek = generic_file_llseek,
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.read_iter = generic_file_read_iter,
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.write_iter = generic_file_write_iter,
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.mmap = generic_file_mmap,
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.fsync = generic_file_fsync,
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.splice_read = generic_file_splice_read,
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};
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const struct inode_operations exfat_file_inode_operations = {
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.setattr = exfat_setattr,
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.getattr = exfat_getattr,
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};
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