From: Yuezhang Mo Yuezhang.Mo@sony.com
[ Upstream commit a3ff29a95fde16906304455aa8c0bd84eb770258 ]
In special cases, a file or a directory may occupied more than 19 directory entries, pre-allocating 3 bh is not enough. Such as - Support vendor secondary directory entry in the future. - Since file directory entry is damaged, the SecondaryCount field is bigger than 18.
So this commit supports dynamic allocation of bh.
Signed-off-by: Yuezhang Mo Yuezhang.Mo@sony.com Reviewed-by: Andy Wu Andy.Wu@sony.com Reviewed-by: Aoyama Wataru wataru.aoyama@sony.com Reviewed-by: Sungjong Seo sj1557.seo@samsung.com Signed-off-by: Namjae Jeon linkinjeon@kernel.org Stable-dep-of: d42334578eba ("exfat: check if filename entries exceeds max filename length") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/exfat/dir.c | 15 +++++++++++++++ fs/exfat/exfat_fs.h | 5 ++++- 2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index 0e1886f9a6241..185aa13945d3d 100644 --- a/fs/exfat/dir.c +++ b/fs/exfat/dir.c @@ -609,6 +609,10 @@ int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync) bforget(es->bh[i]); else brelse(es->bh[i]); + + if (IS_DYNAMIC_ES(es)) + kfree(es->bh); + kfree(es); return err; } @@ -844,6 +848,7 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb, /* byte offset in sector */ off = EXFAT_BLK_OFFSET(byte_offset, sb); es->start_off = off; + es->bh = es->__bh;
/* sector offset in cluster */ sec = EXFAT_B_TO_BLK(byte_offset, sb); @@ -863,6 +868,16 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb, es->num_entries = num_entries;
num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); + if (num_bh > ARRAY_SIZE(es->__bh)) { + es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_KERNEL); + if (!es->bh) { + brelse(bh); + kfree(es); + return NULL; + } + es->bh[0] = bh; + } + for (i = 1; i < num_bh; i++) { /* get the next sector */ if (exfat_is_last_sector_in_cluster(sbi, sec)) { diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h index 436683da2515c..11e579a2598d8 100644 --- a/fs/exfat/exfat_fs.h +++ b/fs/exfat/exfat_fs.h @@ -170,10 +170,13 @@ struct exfat_entry_set_cache { bool modified; unsigned int start_off; int num_bh; - struct buffer_head *bh[DIR_CACHE_SIZE]; + struct buffer_head *__bh[DIR_CACHE_SIZE]; + struct buffer_head **bh; unsigned int num_entries; };
+#define IS_DYNAMIC_ES(es) ((es)->__bh != (es)->bh) + struct exfat_dir_entry { struct exfat_chain dir; int entry;