Quota on and quota off are protected by s_umount semaphore held in
exclusive mode since commit 7d6cd73d33b6 "quota: Hold s_umount in
exclusive mode when enabling / disabling quotas". This makes it
impossible for dquot_disable() to race with other enabling or disabling
of quotas. Simplify the cleanup done by dquot_disable() based on this
fact and also remove some stale comments. As a bonus this cleanup makes
dquot_disable() properly handle a case when there are no quota inodes.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/quota/dquot.c | 73 ++++++++++++++++++++++----------------------------------
1 file changed, 29 insertions(+), 44 deletions(-)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 3e4cf0d10955..4c3da4ea31bc 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2162,14 +2162,29 @@ int dquot_file_open(struct inode *inode, struct file *file)
}
EXPORT_SYMBOL(dquot_file_open);
+static void vfs_cleanup_quota_inode(struct super_block *sb, int type)
+{
+ struct quota_info *dqopt = sb_dqopt(sb);
+ struct inode *inode = dqopt->files[type];
+
+ if (!inode)
+ return;
+ if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
+ inode_lock(inode);
+ inode->i_flags &= ~S_NOQUOTA;
+ inode_unlock(inode);
+ }
+ dqopt->files[type] = NULL;
+ iput(inode);
+}
+
/*
* Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
*/
int dquot_disable(struct super_block *sb, int type, unsigned int flags)
{
- int cnt, ret = 0;
+ int cnt;
struct quota_info *dqopt = sb_dqopt(sb);
- struct inode *toputinode[MAXQUOTAS];
/* s_umount should be held in exclusive mode */
if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
@@ -2191,7 +2206,6 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
return 0;
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
- toputinode[cnt] = NULL;
if (type != -1 && cnt != type)
continue;
if (!sb_has_quota_loaded(sb, cnt))
@@ -2211,8 +2225,7 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
dqopt->flags &= ~dquot_state_flag(
DQUOT_SUSPENDED, cnt);
spin_unlock(&dq_state_lock);
- iput(dqopt->files[cnt]);
- dqopt->files[cnt] = NULL;
+ vfs_cleanup_quota_inode(sb, cnt);
continue;
}
spin_unlock(&dq_state_lock);
@@ -2234,10 +2247,6 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
if (dqopt->ops[cnt]->free_file_info)
dqopt->ops[cnt]->free_file_info(sb, cnt);
put_quota_format(dqopt->info[cnt].dqi_format);
-
- toputinode[cnt] = dqopt->files[cnt];
- if (!sb_has_quota_loaded(sb, cnt))
- dqopt->files[cnt] = NULL;
dqopt->info[cnt].dqi_flags = 0;
dqopt->info[cnt].dqi_igrace = 0;
dqopt->info[cnt].dqi_bgrace = 0;
@@ -2259,32 +2268,22 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
* must also discard the blockdev buffers so that we see the
* changes done by userspace on the next quotaon() */
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
- /* This can happen when suspending quotas on remount-ro... */
- if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) {
- inode_lock(toputinode[cnt]);
- toputinode[cnt]->i_flags &= ~S_NOQUOTA;
- truncate_inode_pages(&toputinode[cnt]->i_data, 0);
- inode_unlock(toputinode[cnt]);
- mark_inode_dirty_sync(toputinode[cnt]);
+ if (!sb_has_quota_loaded(sb, cnt) && dqopt->files[cnt]) {
+ inode_lock(dqopt->files[cnt]);
+ truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
+ inode_unlock(dqopt->files[cnt]);
}
if (sb->s_bdev)
invalidate_bdev(sb->s_bdev);
put_inodes:
+ /* We are done when suspending quotas */
+ if (flags & DQUOT_SUSPENDED)
+ return 0;
+
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
- if (toputinode[cnt]) {
- /* On remount RO, we keep the inode pointer so that we
- * can reenable quota on the subsequent remount RW. We
- * have to check 'flags' variable and not use sb_has_
- * function because another quotaon / quotaoff could
- * change global state before we got here. We refuse
- * to suspend quotas when there is pending delete on
- * the quota file... */
- if (!(flags & DQUOT_SUSPENDED))
- iput(toputinode[cnt]);
- else if (!toputinode[cnt]->i_nlink)
- ret = -EBUSY;
- }
- return ret;
+ if (!sb_has_quota_loaded(sb, cnt))
+ vfs_cleanup_quota_inode(sb, cnt);
+ return 0;
}
EXPORT_SYMBOL(dquot_disable);
@@ -2330,20 +2329,6 @@ static int vfs_setup_quota_inode(struct inode *inode, int type)
return 0;
}
-static void vfs_cleanup_quota_inode(struct super_block *sb, int type)
-{
- struct quota_info *dqopt = sb_dqopt(sb);
- struct inode *inode = dqopt->files[type];
-
- if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
- inode_lock(inode);
- inode->i_flags &= ~S_NOQUOTA;
- inode_unlock(inode);
- }
- dqopt->files[type] = NULL;
- iput(inode);
-}
-
int dquot_load_quota_sb(struct super_block *sb, int type, int format_id,
unsigned int flags)
{
--
2.16.4
