[PATCH v3] quota: propagate error from __dquot_initialize

From: Chao Yu
Date: Tue Nov 28 2017 - 10:02:06 EST


From: Chao Yu <yuchao0@xxxxxxxxxx>

In commit 6184fc0b8dd7 ("quota: Propagate error from ->acquire_dquot()"),
we have propagated error from __dquot_initialize to caller, but we forgot
to handle such error in add_dquot_ref(), so, currently, during quota
accounting information initialization flow, if we failed for some of
inodes, we just ignore such error, and do account for others, which is
not a good implementation.

In this patch, we choose to let user be aware of such error, so after
turning on quota successfully, we can make sure all inodes disk usage
can be accounted, which will be more reasonable.

Suggested-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
v3:
- call dquot_disable with correct args in error path of vfs_load_quota_inode
fs/quota/dquot.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 8381db9db6d9..e44d9e12d885 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -933,12 +933,13 @@ static int dqinit_needed(struct inode *inode, int type)
}

/* This routine is guarded by s_umount semaphore */
-static void add_dquot_ref(struct super_block *sb, int type)
+static int add_dquot_ref(struct super_block *sb, int type)
{
struct inode *inode, *old_inode = NULL;
#ifdef CONFIG_QUOTA_DEBUG
int reserved = 0;
#endif
+ int err = 0;

spin_lock(&sb->s_inode_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
@@ -958,7 +959,11 @@ static void add_dquot_ref(struct super_block *sb, int type)
reserved = 1;
#endif
iput(old_inode);
- __dquot_initialize(inode, type);
+ err = __dquot_initialize(inode, type);
+ if (err) {
+ iput(inode);
+ goto out;
+ }

/*
* We hold a reference to 'inode' so it couldn't have been
@@ -973,7 +978,7 @@ static void add_dquot_ref(struct super_block *sb, int type)
}
spin_unlock(&sb->s_inode_list_lock);
iput(old_inode);
-
+out:
#ifdef CONFIG_QUOTA_DEBUG
if (reserved) {
quota_error(sb, "Writes happened before quota was turned on "
@@ -981,6 +986,7 @@ static void add_dquot_ref(struct super_block *sb, int type)
"Please run quotacheck(8)");
}
#endif
+ return err;
}

/*
@@ -2364,10 +2370,11 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
dqopt->flags |= dquot_state_flag(flags, type);
spin_unlock(&dq_state_lock);

- add_dquot_ref(sb, type);
-
- return 0;
+ error = add_dquot_ref(sb, type);
+ if (error)
+ dquot_disable(sb, type, flags);

+ return error;
out_file_init:
dqopt->files[type] = NULL;
iput(inode);
--
2.14.1.145.gb3622a4ee