From: Mingming Cao Subject: Re: [PATCH V2 2/3] quota: Add quota claim and release reserved quota blocks operations Date: Thu, 06 Nov 2008 15:28:20 -0800 Message-ID: <1226014100.6430.52.camel@mingming-laptop> References: <1225488446.7600.13.camel@mingming-laptop> <20081104172309.b0abc24b.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: jack@suse.cz, tytso@mit.edu, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Andrew Morton Return-path: In-Reply-To: <20081104172309.b0abc24b.akpm@linux-foundation.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Tue, 2008-11-04 at 17:23 -0800, Andrew Morton wrote: > 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. > Agree. I will make the change. > It appears that this optimisation can be made in several places in the > quota code. > That is true. I will create a seperate patch to cleanup this in 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. > >From the comments it seems the DQUOT_XX_XXX micros will be phase out soon, so I assume it is expecting the filesystem to use vfs_dq_xxx() functions? > > #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. > Ok, thanks for point this out. I tested on amd64. > > + 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. > > The one got you confused is dquot_alloc_space(). They are very similar, but have a few subtle differences. Sharing the common code is possible, I tried, the code becomes less readable. I was not sure if it worth the effort so give up. > > +/* > > + * 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. > OK. > > + /* 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. > OK, I think I will just follow Jan's style here now in this series. I will make a seperate cleanup patch to move all the quota exported symbols next to their functions. > > EXPORT_SYMBOL(dquot_transfer); > > EXPORT_SYMBOL(vfs_dq_transfer); > > EXPORT_SYMBOL(vfs_dq_quota_on_remount); > > Attached incremental fix below, please check if I missed any thing, Thanks, Mingming --- fs/dquot.c | 16 +++++++++------- include/linux/quota.h | 6 +++--- include/linux/quotaops.h | 18 ++++++++++-------- 3 files changed, 22 insertions(+), 18 deletions(-) Index: linux-2.6.28-rc2/fs/dquot.c =================================================================== --- linux-2.6.28-rc2.orig/fs/dquot.c 2008-11-06 13:37:06.000000000 -0800 +++ linux-2.6.28-rc2/fs/dquot.c 2008-11-06 13:37:08.000000000 -0800 @@ -853,9 +853,9 @@ static int dquot_claim_reserved_space(st qsize_t number) { if (dquot->dq_dqb.dqb_rsvspace < number) { - printk("WARNING: reserved quota %llu is not enough for" + printk(KERN_WARNING "Reserved quota %llu is not enough for" "request %llu bytes\n", - dquot->dq_dqb.dqb_rsvspace, number); + (unsigned long long)dquot->dq_dqb.dqb_rsvspace, number); return 1; } @@ -1384,13 +1384,11 @@ void dquot_release_reserved_space(struct struct dquot *dquot; if (IS_NOQUOTA(inode)) - return; + goto out; down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); - if (IS_NOQUOTA(inode)) { - up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); - return; - } + if (IS_NOQUOTA(inode)) + goto out_unlock; /* Release reserved dquots */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { @@ -1399,7 +1397,11 @@ void dquot_release_reserved_space(struct dquot->dq_dqb.dqb_rsvspace -= number; } } + +out_unlock: up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); +out: + return; } /* Index: linux-2.6.28-rc2/include/linux/quotaops.h =================================================================== --- linux-2.6.28-rc2.orig/include/linux/quotaops.h 2008-11-06 13:37:06.000000000 -0800 +++ linux-2.6.28-rc2/include/linux/quotaops.h 2008-11-06 14:00:32.000000000 -0800 @@ -206,11 +206,10 @@ static inline int vfs_dq_alloc_inode(str */ static inline int vfs_dq_claim_space(struct inode *inode, qsize_t nr) { - if (sb_any_quota_active(inode->i_sb)){ + if (sb_any_quota_active(inode->i_sb)) { if (inode->i_sb->dq_op->claim_space(inode, nr) == NO_QUOTA) return 1; - } - else + } else inode_add_bytes(inode, nr); mark_inode_dirty(inode); @@ -220,7 +219,8 @@ static inline int vfs_dq_claim_space(str /* * Release reserved (in-memory) quotas */ -static inline void vfs_dq_release_reservation_space(struct inode *inode, qsize_t nr) +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); @@ -377,7 +377,8 @@ static inline int vfs_dq_claim_space(str return vfs_dq_alloc_space(inode, nr); } -static inline int vfs_dq_release_reservation_space(struct inode *inode, qsize_t nr) +static inline +int vfs_dq_release_reservation_space(struct inode *inode, qsize_t nr) { return 0; } @@ -429,12 +430,13 @@ static inline int vfs_dq_reserve_block(s 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); + nr << inode->i_blkbits); } -static inline void vfs_dq_release_reservation(struct inode *inode, qsize_t nr) +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); + vfs_dq_release_reservation_space(inode, nr << inode->i_blkbits); } static inline void vfs_dq_free_block_nodirty(struct inode *inode, qsize_t nr) Index: linux-2.6.28-rc2/include/linux/quota.h =================================================================== --- linux-2.6.28-rc2.orig/include/linux/quota.h 2008-11-06 13:37:06.000000000 -0800 +++ linux-2.6.28-rc2/include/linux/quota.h 2008-11-06 13:37:08.000000000 -0800 @@ -292,9 +292,9 @@ struct dquot_operations { int (*release_dquot) (struct dquot *); /* Quota is going to be deleted from disk */ int (*mark_dirty) (struct dquot *); /* Dquot is marked dirty */ int (*write_info) (struct super_block *, int); /* Write of quota "superblock" */ - int (*reserve_space) (struct inode *, qsize_t, int); /* reserve quota for delayed block allocation */ - int (*claim_space) (struct inode *, qsize_t); /* claim reserved quota for delayed block allocation */ - void (*release_rsv) (struct inode *, qsize_t); /* release reserved quota for delayed block allocation */ + int (*reserve_space) (struct inode *, qsize_t, int); /* reserve quota for delayed alloc */ + int (*claim_space) (struct inode *, qsize_t); /* claim reserved quota for delayed alloc */ + void (*release_rsv) (struct inode *, qsize_t); /* release rsved quota for delayed alloc */ }; /* Operations handling requests from userspace */