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