Re: [PATCH] quota: fix to propagate error of mark_dquot_dirty() to caller

From: Chao Yu
Date: Fri Apr 12 2024 - 21:30:37 EST


On 2024/4/12 21:01, Jan Kara wrote:
On Fri 12-04-24 14:15:17, Jan Kara wrote:
On Fri 12-04-24 17:49:42, Chao Yu wrote:
in order to let caller be aware of failure of mark_dquot_dirty().

Signed-off-by: Chao Yu <chao@xxxxxxxxxx>

Thanks. I've added the patch to my tree.

So this patch was buggy because mark_all_dquots() dirty was returning 1 in
case some dquot was indeed dirtied which resulted in e.g.
dquot_alloc_inode() to return 1 and consequently __ext4_new_inode() to fail

Correct, I missed that case.

and eventually we've crashed in ext4_create(). I've fixed up the patch to
make mark_all_dquots() return 0 or error.

Thank you for catching and fixing it.

Thanks,


Honza

---
fs/quota/dquot.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index dacbee455c03..b2a109d8b198 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1737,7 +1737,7 @@ int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
if (reserve)
goto out_flush_warn;
- mark_all_dquot_dirty(dquots);
+ ret = mark_all_dquot_dirty(dquots);
out_flush_warn:
srcu_read_unlock(&dquot_srcu, index);
flush_warnings(warn);
@@ -1786,7 +1786,7 @@ int dquot_alloc_inode(struct inode *inode)
warn_put_all:
spin_unlock(&inode->i_lock);
if (ret == 0)
- mark_all_dquot_dirty(dquots);
+ ret = mark_all_dquot_dirty(dquots);
srcu_read_unlock(&dquot_srcu, index);
flush_warnings(warn);
return ret;
@@ -1990,7 +1990,7 @@ int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
qsize_t inode_usage = 1;
struct dquot __rcu **dquots;
struct dquot *transfer_from[MAXQUOTAS] = {};
- int cnt, index, ret = 0;
+ int cnt, index, ret = 0, err;
char is_valid[MAXQUOTAS] = {};
struct dquot_warn warn_to[MAXQUOTAS];
struct dquot_warn warn_from_inodes[MAXQUOTAS];
@@ -2087,8 +2087,12 @@ int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
* mark_all_dquot_dirty().
*/
index = srcu_read_lock(&dquot_srcu);
- mark_all_dquot_dirty((struct dquot __rcu **)transfer_from);
- mark_all_dquot_dirty((struct dquot __rcu **)transfer_to);
+ err = mark_all_dquot_dirty((struct dquot __rcu **)transfer_from);
+ if (err < 0)
+ ret = err;
+ err = mark_all_dquot_dirty((struct dquot __rcu **)transfer_to);
+ if (err < 0)
+ ret = err;
srcu_read_unlock(&dquot_srcu, index);
flush_warnings(warn_to);
@@ -2098,7 +2102,7 @@ int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
if (is_valid[cnt])
transfer_to[cnt] = transfer_from[cnt];
- return 0;
+ return ret;
over_quota:
/* Back out changes we already did */
for (cnt--; cnt >= 0; cnt--) {
@@ -2726,6 +2730,7 @@ static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di)
struct mem_dqblk *dm = &dquot->dq_dqb;
int check_blim = 0, check_ilim = 0;
struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
+ int ret;
if (di->d_fieldmask & ~VFS_QC_MASK)
return -EINVAL;
@@ -2807,7 +2812,9 @@ static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di)
else
set_bit(DQ_FAKE_B, &dquot->dq_flags);
spin_unlock(&dquot->dq_dqb_lock);
- mark_dquot_dirty(dquot);
+ ret = mark_dquot_dirty(dquot);
+ if (ret < 0)
+ return ret;
return 0;
}
--
2.40.1

--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR