Commit b0516833 authored by Tetsuhiro Kohada's avatar Tetsuhiro Kohada Committed by Namjae Jeon
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exfat: Unify access to the boot sector 



Unify access to boot sector via 'sbi->pbr_bh'.
This fixes vol_flags inconsistency at read failed in fs_set_vol_flags(),
and buffer_head leak in __exfat_fill_super().

Signed-off-by: default avatarTetsuhiro Kohada <Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp>
Signed-off-by: default avatarNamjae Jeon <namjae.jeon@samsung.com>
parent cd76ac25

fs/exfat/balloc.c

+0 −3
Original line number Diff line number Diff line
@@ -91,7 +91,6 @@ static int exfat_allocate_bitmap(struct super_block *sb, 
		}

	}



	sbi->pbr_bh = NULL;

	return 0;

}
@@ -137,8 +136,6 @@ void exfat_free_bitmap(struct exfat_sb_info *sbi) 
{

	int i;



	brelse(sbi->pbr_bh);



	for (i = 0; i < sbi->map_sectors; i++)

		__brelse(sbi->vol_amap[i]);

fs/exfat/super.c

+16 −27
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ static void exfat_put_super(struct super_block *sb) 
		sync_blockdev(sb->s_bdev);

	exfat_set_vol_flags(sb, VOL_CLEAN);

	exfat_free_bitmap(sbi);

	brelse(sbi->pbr_bh);

	mutex_unlock(&sbi->s_lock);



	call_rcu(&sbi->rcu, exfat_delayed_free);
@@ -100,7 +101,7 @@ static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf) 
int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flag)

{

	struct exfat_sb_info *sbi = EXFAT_SB(sb);

	struct pbr64 *bpb;

	struct pbr64 *bpb = (struct pbr64 *)sbi->pbr_bh->b_data;

	bool sync = 0;



	/* flags are not changed */
@@ -115,15 +116,6 @@ int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flag) 
	if (sb_rdonly(sb))

		return 0;



	if (!sbi->pbr_bh) {

		sbi->pbr_bh = sb_bread(sb, 0);

		if (!sbi->pbr_bh) {

			exfat_msg(sb, KERN_ERR, "failed to read boot sector");

			return -ENOMEM;

		}

	}



	bpb = (struct pbr64 *)sbi->pbr_bh->b_data;

	bpb->bsx.vol_flags = cpu_to_le16(new_flag);



	if (new_flag == VOL_DIRTY && !buffer_dirty(sbi->pbr_bh))
@@ -355,10 +347,10 @@ static int exfat_read_root(struct inode *inode) 
	return 0;

}



static struct pbr *exfat_read_pbr_with_logical_sector(struct super_block *sb,

		struct buffer_head **prev_bh)

static struct pbr *exfat_read_pbr_with_logical_sector(struct super_block *sb)

{

	struct pbr *p_pbr = (struct pbr *) (*prev_bh)->b_data;

	struct exfat_sb_info *sbi = EXFAT_SB(sb);

	struct pbr *p_pbr = (struct pbr *) (sbi->pbr_bh)->b_data;

	unsigned short logical_sect = 0;



	logical_sect = 1 << p_pbr->bsx.f64.sect_size_bits;
@@ -378,26 +370,23 @@ static struct pbr *exfat_read_pbr_with_logical_sector(struct super_block *sb, 
	}



	if (logical_sect > sb->s_blocksize) {

		struct buffer_head *bh = NULL;



		__brelse(*prev_bh);

		*prev_bh = NULL;

		brelse(sbi->pbr_bh);

		sbi->pbr_bh = NULL;



		if (!sb_set_blocksize(sb, logical_sect)) {

			exfat_msg(sb, KERN_ERR,

				"unable to set blocksize %u", logical_sect);

			return NULL;

		}

		bh = sb_bread(sb, 0);

		if (!bh) {

		sbi->pbr_bh = sb_bread(sb, 0);

		if (!sbi->pbr_bh) {

			exfat_msg(sb, KERN_ERR,

				"unable to read boot sector (logical sector size = %lu)",

				sb->s_blocksize);

			return NULL;

		}



		*prev_bh = bh;

		p_pbr = (struct pbr *) bh->b_data;

		p_pbr = (struct pbr *)sbi->pbr_bh->b_data;

	}

	return p_pbr;

}
@@ -408,21 +397,20 @@ static int __exfat_fill_super(struct super_block *sb) 
	int ret;

	struct pbr *p_pbr;

	struct pbr64 *p_bpb;

	struct buffer_head *bh;

	struct exfat_sb_info *sbi = EXFAT_SB(sb);



	/* set block size to read super block */

	sb_min_blocksize(sb, 512);



	/* read boot sector */

	bh = sb_bread(sb, 0);

	if (!bh) {

	sbi->pbr_bh = sb_bread(sb, 0);

	if (!sbi->pbr_bh) {

		exfat_msg(sb, KERN_ERR, "unable to read boot sector");

		return -EIO;

	}



	/* PRB is read */

	p_pbr = (struct pbr *)bh->b_data;

	p_pbr = (struct pbr *)sbi->pbr_bh->b_data;



	/* check the validity of PBR */

	if (le16_to_cpu((p_pbr->signature)) != PBR_SIGNATURE) {
@@ -433,7 +421,7 @@ static int __exfat_fill_super(struct super_block *sb) 




	/* check logical sector size */

	p_pbr = exfat_read_pbr_with_logical_sector(sb, &bh);

	p_pbr = exfat_read_pbr_with_logical_sector(sb);

	if (!p_pbr) {

		ret = -EIO;

		goto free_bh;
@@ -514,7 +502,7 @@ static int __exfat_fill_super(struct super_block *sb) 
free_upcase_table:

	exfat_free_upcase_table(sbi);

free_bh:

	brelse(bh);

	brelse(sbi->pbr_bh);

	return ret;

}
@@ -606,6 +594,7 @@ static int exfat_fill_super(struct super_block *sb, struct fs_context *fc) 
free_table:

	exfat_free_upcase_table(sbi);

	exfat_free_bitmap(sbi);

	brelse(sbi->pbr_bh);



check_nls_io:

	unload_nls(sbi->nls_io);