From b0516833d8096c40ead3169c90d87392fb5f8f45 Mon Sep 17 00:00:00 2001 From: Tetsuhiro Kohada Date: Tue, 21 Apr 2020 10:58:58 +0900 Subject: [Backport b0516833d809] 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 Signed-off-by: Namjae Jeon --- src/balloc.c | 3 --- src/super.c | 43 ++++++++++++++++--------------------------- 2 files changed, 16 insertions(+), 30 deletions(-) diff --git a/src/balloc.c b/src/balloc.c index 6a04cc02565a1f3823ad9a109238bad9553a82f1..6774a5a6ded8290fb790bf70f04a1c6e3253cd7a 100644 --- a/src/balloc.c +++ b/src/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/src/super.c b/src/super.c index 86c87560602400ec2bc7587268bf025cc54e9ce7..6b63e5092628143ba5c8f3a5437eb3f5a1b68ea7 100644 --- a/src/super.c +++ b/src/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; } @@ -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); -- 2.31.1