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-rw-r--r--fs/quota/dquot.c11
-rw-r--r--fs/quota/quota.c16
2 files changed, 24 insertions, 3 deletions
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 1bfac28b7e7d..047afb966420 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2107,6 +2107,10 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
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)))
+ up_read(&sb->s_umount);
+
/* Cannot turn off usage accounting without turning off limits, or
* suspend quotas and simultaneously turn quotas off. */
if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
@@ -2371,6 +2375,10 @@ int dquot_resume(struct super_block *sb, int type)
int ret = 0, cnt;
unsigned int flags;
+ /* s_umount should be held in exclusive mode */
+ if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
+ up_read(&sb->s_umount);
+
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (type != -1 && cnt != type)
continue;
@@ -2430,6 +2438,9 @@ int dquot_enable(struct inode *inode, int type, int format_id,
/* Just unsuspend quotas? */
BUG_ON(flags & DQUOT_SUSPENDED);
+ /* s_umount should be held in exclusive mode */
+ if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
+ up_read(&sb->s_umount);
if (!flags)
return 0;
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 2d445425aad7..6ce6f4b6826b 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -789,9 +789,14 @@ static int quotactl_cmd_write(int cmd)
}
return 1;
}
-
#endif /* CONFIG_BLOCK */
+/* Return true if quotactl command is manipulating quota on/off state */
+static bool quotactl_cmd_onoff(int cmd)
+{
+ return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF);
+}
+
/*
* look up a superblock on which quota ops will be performed
* - use the name of a block device to find the superblock thereon
@@ -809,7 +814,9 @@ static struct super_block *quotactl_block(const char __user *special, int cmd)
putname(tmp);
if (IS_ERR(bdev))
return ERR_CAST(bdev);
- if (quotactl_cmd_write(cmd))
+ if (quotactl_cmd_onoff(cmd))
+ sb = get_super_exclusive_thawed(bdev);
+ else if (quotactl_cmd_write(cmd))
sb = get_super_thawed(bdev);
else
sb = get_super(bdev);
@@ -872,7 +879,10 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
ret = do_quotactl(sb, type, cmds, id, addr, pathp);
- drop_super(sb);
+ if (!quotactl_cmd_onoff(cmds))
+ drop_super(sb);
+ else
+ drop_super_exclusive(sb);
out:
if (pathp && !IS_ERR(pathp))
path_put(pathp);