diff options
Diffstat (limited to 'fs/exfat/dir.c')
-rw-r--r-- | fs/exfat/dir.c | 197 |
1 files changed, 75 insertions, 122 deletions
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index b5a237c33d50..2902d285bf20 100644 --- a/fs/exfat/dir.c +++ b/fs/exfat/dir.c @@ -32,35 +32,30 @@ static void exfat_get_uniname_from_ext_entry(struct super_block *sb, struct exfat_chain *p_dir, int entry, unsigned short *uniname) { int i; - struct exfat_dentry *ep; struct exfat_entry_set_cache *es; - es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES, &ep); + es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES); if (!es) return; - if (es->num_entries < 3) - goto free_es; - - ep += 2; - /* * First entry : file entry * Second entry : stream-extension entry * Third entry : first file-name entry * So, the index of first file-name dentry should start from 2. */ - for (i = 2; i < es->num_entries; i++, ep++) { + for (i = 2; i < es->num_entries; i++) { + struct exfat_dentry *ep = exfat_get_dentry_cached(es, i); + /* end of name entry */ if (exfat_get_entry_type(ep) != TYPE_EXTEND) - goto free_es; + break; exfat_extract_uni_name(ep, uniname); uniname += EXFAT_FILE_NAME_LEN; } -free_es: - kfree(es); + exfat_free_dentry_set(es, false); } /* read a directory entry from the opened directory */ @@ -590,62 +585,33 @@ int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir, return 0; } -int exfat_update_dir_chksum_with_entry_set(struct super_block *sb, - struct exfat_entry_set_cache *es, int sync) +void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es) { - struct exfat_sb_info *sbi = EXFAT_SB(sb); - struct buffer_head *bh; - sector_t sec = es->sector; - unsigned int off = es->offset; - int chksum_type = CS_DIR_ENTRY, i, num_entries = es->num_entries; - unsigned int buf_off = (off - es->offset); - unsigned int remaining_byte_in_sector, copy_entries, clu; + int chksum_type = CS_DIR_ENTRY, i; unsigned short chksum = 0; + struct exfat_dentry *ep; - for (i = 0; i < num_entries; i++) { - chksum = exfat_calc_chksum_2byte(&es->entries[i], DENTRY_SIZE, - chksum, chksum_type); + for (i = 0; i < es->num_entries; i++) { + ep = exfat_get_dentry_cached(es, i); + chksum = exfat_calc_chksum_2byte(ep, DENTRY_SIZE, chksum, + chksum_type); chksum_type = CS_DEFAULT; } + ep = exfat_get_dentry_cached(es, 0); + ep->dentry.file.checksum = cpu_to_le16(chksum); + es->modified = true; +} - es->entries[0].dentry.file.checksum = cpu_to_le16(chksum); +void exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync) +{ + int i; - while (num_entries) { - /* write per sector base */ - remaining_byte_in_sector = (1 << sb->s_blocksize_bits) - off; - copy_entries = min_t(int, - EXFAT_B_TO_DEN(remaining_byte_in_sector), - num_entries); - bh = sb_bread(sb, sec); - if (!bh) - goto err_out; - memcpy(bh->b_data + off, - (unsigned char *)&es->entries[0] + buf_off, - EXFAT_DEN_TO_B(copy_entries)); - exfat_update_bh(sb, bh, sync); - brelse(bh); - num_entries -= copy_entries; - - if (num_entries) { - /* get next sector */ - if (exfat_is_last_sector_in_cluster(sbi, sec)) { - clu = exfat_sector_to_cluster(sbi, sec); - if (es->alloc_flag == ALLOC_NO_FAT_CHAIN) - clu++; - else if (exfat_get_next_cluster(sb, &clu)) - goto err_out; - sec = exfat_cluster_to_sector(sbi, clu); - } else { - sec++; - } - off = 0; - buf_off += EXFAT_DEN_TO_B(copy_entries); - } + for (i = 0; i < es->num_bh; i++) { + if (es->modified) + exfat_update_bh(es->sb, es->bh[i], sync); + brelse(es->bh[i]); } - - return 0; -err_out: - return -EIO; + kfree(es); } static int exfat_walk_fat_chain(struct super_block *sb, @@ -820,34 +786,40 @@ static bool exfat_validate_entry(unsigned int type, } } +struct exfat_dentry *exfat_get_dentry_cached( + struct exfat_entry_set_cache *es, int num) +{ + int off = es->start_off + num * DENTRY_SIZE; + struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; + char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); + + return (struct exfat_dentry *)p; +} + /* * Returns a set of dentries for a file or dir. * - * Note that this is a copy (dump) of dentries so that user should - * call write_entry_set() to apply changes made in this entry set - * to the real device. + * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). + * User should call exfat_get_dentry_set() after setting 'modified' to apply + * changes made in this entry set to the real device. * * in: * sb+p_dir+entry: indicates a file/dir * type: specifies how many dentries should be included. - * out: - * file_ep: will point the first dentry(= file dentry) on success * return: * pointer of entry set on success, * NULL on failure. */ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb, - struct exfat_chain *p_dir, int entry, unsigned int type, - struct exfat_dentry **file_ep) + struct exfat_chain *p_dir, int entry, unsigned int type) { - int ret; + int ret, i, num_bh; unsigned int off, byte_offset, clu = 0; - unsigned int entry_type; sector_t sec; struct exfat_sb_info *sbi = EXFAT_SB(sb); struct exfat_entry_set_cache *es; - struct exfat_dentry *ep, *pos; - unsigned char num_entries; + struct exfat_dentry *ep; + int num_entries; enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; struct buffer_head *bh; @@ -861,11 +833,18 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb, if (ret) return NULL; + es = kzalloc(sizeof(*es), GFP_KERNEL); + if (!es) + return NULL; + es->sb = sb; + es->modified = false; + /* byte offset in cluster */ byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi); /* byte offset in sector */ off = EXFAT_BLK_OFFSET(byte_offset, sb); + es->start_off = off; /* sector offset in cluster */ sec = EXFAT_B_TO_BLK(byte_offset, sb); @@ -873,72 +852,46 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb, bh = sb_bread(sb, sec); if (!bh) - return NULL; - - ep = (struct exfat_dentry *)(bh->b_data + off); - entry_type = exfat_get_entry_type(ep); + goto free_es; + es->bh[es->num_bh++] = bh; - if (entry_type != TYPE_FILE && entry_type != TYPE_DIR) - goto release_bh; + ep = exfat_get_dentry_cached(es, 0); + if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) + goto free_es; num_entries = type == ES_ALL_ENTRIES ? ep->dentry.file.num_ext + 1 : type; - es = kmalloc(struct_size(es, entries, num_entries), GFP_KERNEL); - if (!es) - goto release_bh; - es->num_entries = num_entries; - es->sector = sec; - es->offset = off; - es->alloc_flag = p_dir->flags; - - pos = &es->entries[0]; - - while (num_entries) { - if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) - goto free_es; - /* copy dentry */ - memcpy(pos, ep, sizeof(struct exfat_dentry)); - - if (--num_entries == 0) - break; - - if (((off + DENTRY_SIZE) & (sb->s_blocksize - 1)) < - (off & (sb->s_blocksize - 1))) { - /* get the next sector */ - if (exfat_is_last_sector_in_cluster(sbi, sec)) { - if (es->alloc_flag == ALLOC_NO_FAT_CHAIN) - clu++; - else if (exfat_get_next_cluster(sb, &clu)) - goto free_es; - sec = exfat_cluster_to_sector(sbi, clu); - } else { - sec++; - } - - brelse(bh); - bh = sb_bread(sb, sec); - if (!bh) + num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); + for (i = 1; i < num_bh; i++) { + /* get the next sector */ + if (exfat_is_last_sector_in_cluster(sbi, sec)) { + if (p_dir->flags == ALLOC_NO_FAT_CHAIN) + clu++; + else if (exfat_get_next_cluster(sb, &clu)) goto free_es; - off = 0; - ep = (struct exfat_dentry *)bh->b_data; + sec = exfat_cluster_to_sector(sbi, clu); } else { - ep++; - off += DENTRY_SIZE; + sec++; } - pos++; + + bh = sb_bread(sb, sec); + if (!bh) + goto free_es; + es->bh[es->num_bh++] = bh; } - if (file_ep) - *file_ep = &es->entries[0]; - brelse(bh); + /* validiate cached dentries */ + for (i = 1; i < num_entries; i++) { + ep = exfat_get_dentry_cached(es, i); + if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) + goto free_es; + } return es; free_es: - kfree(es); -release_bh: - brelse(bh); + exfat_free_dentry_set(es, false); return NULL; } |