From: Jan Kara Subject: Re: [PATCH V5 2/5] quota: Add quota claim and release reserved quota blocks operations Date: Tue, 6 Jan 2009 10:52:52 +0100 Message-ID: <20090106095252.GG10705@duck.suse.cz> References: <1231216837.9267.24.camel@mingming-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Morton , Jan Kara , tytso , linux-ext4 , linux-fsdevel To: Mingming Cao Return-path: Content-Disposition: inline In-Reply-To: <1231216837.9267.24.camel@mingming-laptop> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Hi, On Mon 05-01-09 20:40:37, Mingming Cao wrote: > quota: Add quota reservation claim and released operations > > Reserved quota will be claimed at the block allocation time. Over-booked > quota could be returned back with the release callback function. > > Signed-off-by: Mingming Cao Just a few minor comments below. > --- > fs/dquot.c | 113 +++++++++++++++++++++++++++++++++++++++++++++-- > include/linux/quota.h | 6 ++ > include/linux/quotaops.h | 53 ++++++++++++++++++++++ > 3 files changed, 168 insertions(+), 4 deletions(-) > > Index: linux-2.6.28-git7/include/linux/quota.h > =================================================================== > --- linux-2.6.28-git7.orig/include/linux/quota.h 2009-01-05 17:26:47.000000000 -0800 > +++ linux-2.6.28-git7/include/linux/quota.h 2009-01-05 17:26:48.000000000 -0800 > @@ -311,6 +311,12 @@ struct dquot_operations { > int (*write_info) (struct super_block *, int); /* Write of quota "superblock" */ > /* reserve quota for delayed block allocation */ > int (*reserve_space) (struct inode *, qsize_t, int); > + /* claim reserved quota for delayed alloc */ > + int (*claim_space) (struct inode *, qsize_t); > + /* release rsved quota for delayed alloc */ > + void (*release_rsv) (struct inode *, qsize_t); > + /* get reserved quota for delayed alloc */ > + unsigned long long (*get_reserved_space) (struct inode *); ^^^ qsize_t would be more appropriate here IMO. > }; > > /* Operations handling requests from userspace */ > Index: linux-2.6.28-git7/fs/dquot.c > =================================================================== > --- linux-2.6.28-git7.orig/fs/dquot.c 2009-01-05 17:26:47.000000000 -0800 > +++ linux-2.6.28-git7/fs/dquot.c 2009-01-05 20:06:23.000000000 -0800 > @@ -903,6 +903,23 @@ static inline void dquot_resv_space(stru > dquot->dq_dqb.dqb_rsvspace += number; > } > > +/* > + * Claim reserved quota space > + */ > +static void dquot_claim_reserved_space(struct dquot *dquot, > + qsize_t number) > +{ > + WARN_ON(dquot->dq_dqb.dqb_rsvspace < number); > + dquot->dq_dqb.dqb_curspace += number; > + dquot->dq_dqb.dqb_rsvspace -= number; > +} > + > +static inline > +void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) > +{ > + dquot->dq_dqb.dqb_rsvspace -= number; > +} > + > static inline void dquot_decr_inodes(struct dquot *dquot, qsize_t number) > { > if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || > @@ -1432,6 +1449,75 @@ warn_put_all: > return ret; > } > > +int dquot_claim_space(struct inode *inode, qsize_t number) > +{ > + int cnt; > + int ret = QUOTA_OK; > + > + if (IS_NOQUOTA(inode)) { > + inode_add_bytes(inode, number); > + goto out; > + } > + > + down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); > + if (IS_NOQUOTA(inode)) { > + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); > + inode_add_bytes(inode, number); > + goto out; > + } > + > + spin_lock(&dq_data_lock); > + /* Claim reserved quotas to allocated quotas */ > + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { > + if (inode->i_dquot[cnt] != NODQUOT) > + dquot_claim_reserved_space(inode->i_dquot[cnt], > + number); > + } > + /* Update inode bytes */ > + inode_add_bytes(inode, number); > + spin_unlock(&dq_data_lock); > + /* Dirtify all the dquots - this can block when journalling */ > + for (cnt = 0; cnt < MAXQUOTAS; cnt++) > + if (inode->i_dquot[cnt]) > + mark_dquot_dirty(inode->i_dquot[cnt]); > + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); > +out: > + return ret; > +} > +EXPORT_SYMBOL(dquot_claim_space); > + > +/* > + * Release reserved quota space > + */ > +void dquot_release_reserved_space(struct inode *inode, qsize_t number) > +{ > + int cnt; > + struct dquot *dquot; > + > + if (IS_NOQUOTA(inode)) > + goto out; > + > + down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); > + if (IS_NOQUOTA(inode)) > + goto out_unlock; > + > + spin_lock(&dq_data_lock); > + /* Release reserved dquots */ > + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { > + if (inode->i_dquot[cnt] != NODQUOT) { > + dquot = inode->i_dquot[cnt]; > + dquot_free_reserved_space(dquot, number); > + } > + } > + spin_unlock(&dq_data_lock); Variable dquot seems to be quite useless here... > + > +out_unlock: > + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); > +out: > + return; > +} > +EXPORT_SYMBOL(dquot_release_reserved_space); > + > /* > * This operation can block, but only after everything is updated > */ > @@ -1507,6 +1593,19 @@ int dquot_free_inode(const struct inode > up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); > return QUOTA_OK; > } Empty line here? > +/* > + * call back function, get reserved quota space from underlying fs > + */ > +qsize_t dquot_get_reserved_space(struct inode *inode) > +{ > + qsize_t reserved_space = 0; > + > + if (sb_any_quota_active(inode->i_sb) && > + inode->i_sb->dq_op->get_reserved_space) > + reserved_space = inode->i_sb->dq_op->get_reserved_space(inode) > + << inode->i_blkbits; > + return reserved_space; > +} The function should really return number of bytes as its name suggests. In principle there's no reason why inode could not have 5 bytes reserved :). Hmm, sorry for my comment to ext4 patch. That is correct given what is written here. I was just confused by the name of the callback. > /* > * Transfer the number of inode and blocks from one diskquota to an other. > @@ -1516,7 +1615,8 @@ int dquot_free_inode(const struct inode > */ > int dquot_transfer(struct inode *inode, struct iattr *iattr) > { > - qsize_t space; > + qsize_t space, cur_space; > + qsize_t rsv_space = 0; > struct dquot *transfer_from[MAXQUOTAS]; > struct dquot *transfer_to[MAXQUOTAS]; > int cnt, ret = NO_QUOTA, chuid = (iattr->ia_valid & ATTR_UID) && inode->i_uid != iattr->ia_uid, > @@ -1557,7 +1657,9 @@ int dquot_transfer(struct inode *inode, > } > } > spin_lock(&dq_data_lock); > - space = inode_get_bytes(inode); > + cur_space = inode_get_bytes(inode); > + rsv_space = dquot_get_reserved_space(inode); > + space = cur_space + rsv_space; > /* Build the transfer_from list and check the limits */ > for (cnt = 0; cnt < MAXQUOTAS; cnt++) { > if (transfer_to[cnt] == NODQUOT) > @@ -1586,11 +1688,14 @@ int dquot_transfer(struct inode *inode, > warntype_from_space[cnt] = > info_bdq_free(transfer_from[cnt], space); > dquot_decr_inodes(transfer_from[cnt], 1); > - dquot_decr_space(transfer_from[cnt], space); > + dquot_decr_space(transfer_from[cnt], cur_space); > + dquot_free_reserved_space(transfer_from[cnt], > + rsv_space); > } > > dquot_incr_inodes(transfer_to[cnt], 1); > - dquot_incr_space(transfer_to[cnt], space); > + dquot_incr_space(transfer_to[cnt], cur_space); > + dquot_resv_space(transfer_to[cnt], rsv_space); > > inode->i_dquot[cnt] = transfer_to[cnt]; > } Honza -- Jan Kara SUSE Labs, CR