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exfat: Unify access to the boot sector

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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: Tetsuhiro Kohada <Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
This commit is contained in:
Tetsuhiro Kohada 2020-04-21 10:58:58 +09:00 committed by Namjae Jeon
parent cd76ac258c
commit b0516833d8
2 changed files with 16 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
fs/exfat/balloc.c
View File

@ -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]);

43
fs/exfat/super.c
View File

@ -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 @@ free_alloc_bitmap:
free_upcase_table:
exfat_free_upcase_table(sbi);
free_bh:
brelse(bh);
brelse(sbi->pbr_bh);
return ret;
}
@ -606,6 +594,7 @@ put_inode:
free_table:
exfat_free_upcase_table(sbi);
exfat_free_bitmap(sbi);
brelse(sbi->pbr_bh);
check_nls_io:
unload_nls(sbi->nls_io);