On Thu 08-04-10 22:04:22, Dmitry Monakhov wrote:
> Due to previous IO error or other bugs an inode may not has quota
> pointer. This definite sign of quota inconsistency/corruption.
> In fact this condition must being checked in all charge/uncharge
> functions. And if error was detected it is reasonable to fail whole
> operation. But uncharge(free_space/claim_space/free_inode) functions
> has no fail nature. This is because caller can't handle errors from
> such functions. How can you handle error from following call-trace?
> write_page()->quota_claim_space()
>
> So alloc_space() and alloc_inode() are the only functions which we may
> reliably abort in case of any errors.
>
> This patch add corresponding checks only for charge functions.
>
> Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
> ---
> fs/quota/dquot.c | 39 +++++++++++++++++++++++++++++++++------
> 1 files changed, 33 insertions(+), 6 deletions(-)
>
> diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
> index 3f4541e..7480e03 100644
> --- a/fs/quota/dquot.c
> +++ b/fs/quota/dquot.c
> @@ -1529,13 +1529,27 @@ int __dquot_alloc_space(struct inode *inode, qsize_t number,
> }
>
> down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
> + /* Now recheck reliably when holding dqptr_sem */
> + if (!(active = sb_any_quota_active(inode->i_sb)) || IS_NOQUOTA(inode)) {
Please don't use assignment in conditions... It's against kernel's coding
style.
> + inode_incr_space(inode, number, reserve);
> + goto out;
> + }
> +
> for (cnt = 0; cnt < MAXQUOTAS; cnt++)
> warntype[cnt] = QUOTA_NL_NOWARN;
>
> spin_lock(&dq_data_lock);
> for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
> - if (!inode->i_dquot[cnt])
> + if (!(active & (1 << cnt)))
> continue;
> + /*
> + * Given quota type is active, so quota must being
> + * initialized for this inode
> + */
> + if (!inode->i_dquot[cnt]) {
> + ret = -EIO;
Umm, I don't like this. I think we should just silently skip the quota
modification. The error has already been passed to the filesystem during
dquot_initialize and this would effectively disallow any allocation on the
filesystem if quota structure isn't available which might be a bit
impractical.
Honza
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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