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Message-Id: <20200401091745.107261-1-Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp>
Date: Wed, 1 Apr 2020 18:17:45 +0900
From: Tetsuhiro Kohada <Kohada.Tetsuhiro@...MitsubishiElectric.co.jp>
To: Kohada.Tetsuhiro@...MitsubishiElectric.co.jp
Cc: Mori.Takahiro@...MitsubishiElectric.co.jp,
motai.hirotaka@...mitsubishielectric.co.jp,
Namjae Jeon <namjae.jeon@...sung.com>,
Sungjong Seo <sj1557.seo@...sung.com>,
linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] 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: Tetsuhiro Kohada <Kohada.Tetsuhiro@...MitsubishiElectric.co.jp>
---
fs/exfat/balloc.c | 3 ---
fs/exfat/super.c | 43 ++++++++++++++++---------------------------
2 files changed, 16 insertions(+), 30 deletions(-)
diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c
index 6a04cc0256..6774a5a6de 100644
--- a/fs/exfat/balloc.c
+++ b/fs/exfat/balloc.c
@@ -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]);
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index 16ed202ef5..2dd62543a4 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -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;
}
@@ -605,6 +593,7 @@ 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);
--
2.25.0
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