From: Andrew Morton Subject: Re: [PATCH V2 2/3] quota: Add quota claim and release reserved quota blocks operations Date: Tue, 4 Nov 2008 17:23:09 -0800 Message-ID: <20081104172309.b0abc24b.akpm@linux-foundation.org> References: <1225488446.7600.13.camel@mingming-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: jack@suse.cz, tytso@mit.edu, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Mingming Cao Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:48169 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753059AbYKEBXS (ORCPT ); Tue, 4 Nov 2008 20:23:18 -0500 In-Reply-To: <1225488446.7600.13.camel@mingming-laptop> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, 31 Oct 2008 14:27:26 -0700 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. > > --- linux-2.6.28-rc2.orig/include/linux/quotaops.h 2008-10-30 14:41:35.000000000 -0700 > +++ linux-2.6.28-rc2/include/linux/quotaops.h 2008-10-30 14:42:00.000000000 -0700 > @@ -28,6 +28,11 @@ int dquot_drop(struct inode *inode); > int dquot_alloc_space(struct inode *inode, qsize_t number, int prealloc); > int dquot_alloc_inode(const struct inode *inode, qsize_t number); > > +int dquot_reserve_space(struct inode *inode, qsize_t number, int prealloc); > +int dquot_claim_space(struct inode *inode, qsize_t number); > +void dquot_release_reserved_space(struct inode *inode, qsize_t number); > + > + > int dquot_free_space(struct inode *inode, qsize_t number); > int dquot_free_inode(const struct inode *inode, qsize_t number); > > @@ -196,6 +201,31 @@ static inline int vfs_dq_alloc_inode(str > return 0; > } > > +/* > + * Convert in-memory reserved quotas to real consumed quotas > + */ > +static inline int vfs_dq_claim_space(struct inode *inode, qsize_t nr) > +{ > + if (sb_any_quota_active(inode->i_sb)){ > + if (inode->i_sb->dq_op->claim_space(inode, nr) == NO_QUOTA) > + return 1; > + } > + else > + inode_add_bytes(inode, nr); > + > + mark_inode_dirty(inode); > + return 0; > +} The amount of inlining in this code is, umm, suboptimal. Thankfully there only appears to be a single DQUOT_CLAIM_BLOCK() callsite at this stage. I blame Jan ;) > +/* > + * Release reserved (in-memory) quotas > + */ > +static inline void vfs_dq_release_reservation_space(struct inode *inode, qsize_t nr) > +{ > + if (sb_any_quota_active(inode->i_sb)) > + inode->i_sb->dq_op->release_rsv(inode, nr); > +} > + > static inline void vfs_dq_free_space_nodirty(struct inode *inode, qsize_t nr) > { > if (sb_any_quota_active(inode->i_sb)) > @@ -342,6 +372,16 @@ static inline int vfs_dq_reserve_space(s > return 0; > } > > +static inline int vfs_dq_claim_space(struct inode *inode, qsize_t nr) > +{ > + return vfs_dq_alloc_space(inode, nr); > +} > + > +static inline int vfs_dq_release_reservation_space(struct inode *inode, qsize_t nr) > +{ > + return 0; > +} > + > static inline void vfs_dq_free_space_nodirty(struct inode *inode, qsize_t nr) > { > inode_sub_bytes(inode, nr); > @@ -386,6 +426,17 @@ static inline int vfs_dq_reserve_block(s > nr << inode->i_sb->s_blocksize_bits); > } > > +static inline int vfs_dq_claim_block(struct inode *inode, qsize_t nr) > +{ > + return vfs_dq_claim_space(inode, > + nr << inode->i_sb->s_blocksize_bits); > +} > + > +static inline void vfs_dq_release_reservation(struct inode *inode, qsize_t nr) > +{ > + vfs_dq_release_reservation_space(inode, nr << inode->i_sb->s_blocksize_bits); I think you'll find that inode->i_blkbits contains the same information. Accessing that is faster and will emit less code. It appears that this optimisation can be made in several places in the quota code. > +} > + > static inline void vfs_dq_free_block_nodirty(struct inode *inode, qsize_t nr) > { > vfs_dq_free_space_nodirty(inode, nr << inode->i_sb->s_blocksize_bits); > @@ -415,6 +466,8 @@ static inline void vfs_dq_free_block(str > vfs_dq_alloc_block_nodirty(inode, nr) > #define DQUOT_ALLOC_BLOCK(inode, nr) vfs_dq_alloc_block(inode, nr) > #define DQUOT_RESERVE_BLOCK(inode, nr) vfs_dq_reserve_block(inode, nr) > +#define DQUOT_CLAIM_BLOCK(inode, nr) vfs_dq_claim_block(inode, nr) > +#define DQUOT_RELEASE_RSV_BLOCK(inode, nr) vfs_dq_release_reservation(inode, nr) erk. I blame him for this too. > #define DQUOT_ALLOC_INODE(inode) vfs_dq_alloc_inode(inode) > #define DQUOT_FREE_SPACE_NODIRTY(inode, nr) \ > vfs_dq_free_space_nodirty(inode, nr) > Index: linux-2.6.28-rc2/fs/dquot.c > =================================================================== > --- linux-2.6.28-rc2.orig/fs/dquot.c 2008-10-30 14:41:50.000000000 -0700 > +++ linux-2.6.28-rc2/fs/dquot.c 2008-10-31 13:27:20.000000000 -0700 > @@ -846,6 +846,24 @@ static inline void dquot_resv_space(stru > dquot->dq_dqb.dqb_rsvspace += number; > } > > +/* > + * Claim reserved quota space > + */ > +static int dquot_claim_reserved_space(struct dquot *dquot, > + qsize_t number) > +{ > + if (dquot->dq_dqb.dqb_rsvspace < number) { > + printk("WARNING: reserved quota %llu is not enough for" > + "request %llu bytes\n", > + dquot->dq_dqb.dqb_rsvspace, number); Nope. You cannot print a u64 - you do not know what type it has. It must be typecast to a known type for printing purposes. This mistake seems to be happening a lot in ext4 world. People, please remember this! You might want to have a think about your compilation test coverage also. powerpc and sparc64 are good ones to use. > + return 1; > + } > + > + dquot->dq_dqb.dqb_curspace += number; > + dquot->dq_dqb.dqb_rsvspace -= number; > + return 0; > +} > + > static inline void dquot_decr_inodes(struct dquot *dquot, qsize_t number) > { > if (dquot->dq_dqb.dqb_curinodes > number) > @@ -1325,6 +1343,71 @@ int dquot_reserve_space(struct inode *in > 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); > + return ret; > + } > + > + 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); > + return ret; > + } > + > + /* Claim reserved quotas to allocated quotas */ > + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { > + if (inode->i_dquot[cnt] != NODQUOT) > + ret = dquot_claim_reserved_space(inode->i_dquot[cnt], > + number); > + } > + if (ret == NO_QUOTA) { > + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); > + return ret; > + } > + /* 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); > + > + /* Update inode bytes */ > + inode_add_bytes(inode, number); > + return ret; > +} Didn't I just review that function? I might have got my patches confused. > +/* > + * Release reserved quota space > + */ > +void dquot_release_reserved_space(struct inode *inode, qsize_t number) > +{ > + int cnt; > + struct dquot *dquot; > + > + if (IS_NOQUOTA(inode)) > + return; > + > + down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); > + if (IS_NOQUOTA(inode)) { > + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); > + return; > + } again, `goto out' will yield more maintainable and perhaps more efficient code here. > + /* Release reserved dquots */ > + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { > + if (inode->i_dquot[cnt] != NODQUOT) { > + dquot = inode->i_dquot[cnt]; > + dquot->dq_dqb.dqb_rsvspace -= number; > + } > + } > + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); > +} > + > /* > * This operation can block, but only after everything is updated > */ > @@ -2350,6 +2433,8 @@ EXPORT_SYMBOL(dquot_alloc_inode); > EXPORT_SYMBOL(dquot_free_space); > EXPORT_SYMBOL(dquot_free_inode); > EXPORT_SYMBOL(dquot_reserve_space); > +EXPORT_SYMBOL(dquot_claim_space); > +EXPORT_SYMBOL(dquot_release_reserved_space); I blame him for that too. > EXPORT_SYMBOL(dquot_transfer); > EXPORT_SYMBOL(vfs_dq_transfer); > EXPORT_SYMBOL(vfs_dq_quota_on_remount); >