> Add validation for num, bh and type on getting dir-entry.
> ('file' and 'stream-ext' dir-entries are pre-validated to ensure success)
> Renamed exfat_get_dentry_cached() to exfat_get_validated_dentry() due to a
> change in functionality.
>
> Integrate type-validation with simplified.
> This will also recognize a dir-entry set that contains 'benign secondary'
> dir-entries.
>
> And, rename TYPE_EXTEND to TYPE_NAME.
>
> Suggested-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx>
> Signed-off-by: Tetsuhiro Kohada <kohada.t2@xxxxxxxxx>
> ---
> fs/exfat/dir.c | 144 ++++++++++++++++++--------------------------
> fs/exfat/exfat_fs.h | 15 +++--
> fs/exfat/file.c | 4 +-
> fs/exfat/inode.c | 6 +-
> fs/exfat/namei.c | 4 +-
> 5 files changed, 73 insertions(+), 100 deletions(-)
>
> diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index
> f4cea9a7fd02..e029e0986edc 100644
> --- a/fs/exfat/dir.c
> +++ b/fs/exfat/dir.c
[snip]
> */
> 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_chain *p_dir, int entry, int max_entries)
> {
> int ret, i, num_bh;
> - unsigned int off, byte_offset, clu = 0;
> + unsigned int byte_offset, clu = 0;
> sector_t sec;
> struct exfat_sb_info *sbi = EXFAT_SB(sb);
> struct exfat_entry_set_cache *es;
> struct exfat_dentry *ep;
> - int num_entries;
> - enum exfat_validate_dentry_mode mode = ES_MODE_STARTED;
> struct buffer_head *bh;
>
> if (p_dir->dir == DIR_DELETED) {
> @@ -844,13 +815,13 @@ struct exfat_entry_set_cache
> *exfat_get_dentry_set(struct super_block *sb,
> return NULL;
> es->sb = sb;
> es->modified = false;
> + es->num_entries = 1;
>
> /* 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;
> + es->start_off = EXFAT_BLK_OFFSET(byte_offset, sb);
>
> /* sector offset in cluster */
> sec = EXFAT_B_TO_BLK(byte_offset, sb); @@ -861,15 +832,12 @@ struct
> exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
> goto free_es;
> es->bh[es->num_bh++] = bh;
>
> - ep = exfat_get_dentry_cached(es, 0);
> - if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
> + ep = exfat_get_validated_dentry(es, 0, TYPE_FILE);
> + if (!ep)
> goto free_es;
> + es->num_entries = min(ep->dentry.file.num_ext + 1, max_entries);
>
> - num_entries = type == ES_ALL_ENTRIES ?
> - ep->dentry.file.num_ext + 1 : type;
> - es->num_entries = num_entries;
> -
> - num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE,
> sb);
> + num_bh = EXFAT_B_TO_BLK_ROUND_UP(es->start_off + es->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)) { @@ -889,11
> +857,13 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct
> super_block *sb,
> }
>
> /* 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))
> + for (i = 1; i < es->num_entries; i++) {
> + if (!exfat_get_validated_dentry(es, i, TYPE_SECONDARY))
> goto free_es;
> }
> + if (!exfat_get_validated_dentry(es, 1, TYPE_STREAM))
> + goto free_es;
It looks better to move checking TYPE_STREAM above the for-loop.
And then for-loop should start from index 2.
BTW, do you think it is enough to check only TYPE_SECONDARY not TYPE NAME?
As you might know, FILE, STREAM and NAME entries must be consecutive in
order.
> +
> return es;
>
