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| author | Jan Kara | 2017-06-09 11:56:06 +0200 |
|---|---|---|
| committer | Jan Kara | 2017-08-17 22:00:04 +0200 |
| commit | 15512377bd971ecc86f2eab40b841b265b5043de (patch) | |
| tree | e11553b59233f1e4b836061ec2a39a3610cb1d61 /fs/quota/dquot.c | |
| parent | quota: Propagate ->quota_read errors from v2_read_file_info() (diff) | |
| download | kernel-qcow2-linux-15512377bd971ecc86f2eab40b841b265b5043de.tar.gz kernel-qcow2-linux-15512377bd971ecc86f2eab40b841b265b5043de.tar.xz kernel-qcow2-linux-15512377bd971ecc86f2eab40b841b265b5043de.zip | |
quota: Fix possible corruption of dqi_flags
dqi_flags modifications are protected by dq_data_lock. However the
modifications in vfs_load_quota_inode() and in mark_info_dirty() were
not which could lead to corruption of dqi_flags. Since modifications to
dqi_flags are rare, this is hard to observe in practice but in theory it
could happen. Fix the problem by always using dq_data_lock for
protection.
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/quota/dquot.c')
| -rw-r--r-- | fs/quota/dquot.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 5e77c4da69a6..e1a155e8db15 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -389,7 +389,9 @@ static inline int clear_dquot_dirty(struct dquot *dquot) void mark_info_dirty(struct super_block *sb, int type) { - set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags); + spin_lock(&dq_data_lock); + sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY; + spin_unlock(&dq_data_lock); } EXPORT_SYMBOL(mark_info_dirty); @@ -2316,8 +2318,11 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, error = dqopt->ops[type]->read_file_info(sb, type); if (error < 0) goto out_file_init; - if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) + if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { + spin_lock(&dq_data_lock); dqopt->info[type].dqi_flags |= DQF_SYS_FILE; + spin_unlock(&dq_data_lock); + } spin_lock(&dq_state_lock); dqopt->flags |= dquot_state_flag(flags, type); spin_unlock(&dq_state_lock); |