Currently inode_reservation is managed by fs itself and this reservation is transfered on dquot_transfer(). This means what inode_reservation must always be in sync with dquot->dq_dqb.dqb_rsvspace. Otherwise dquot_transfer() will result in incorrect quota(WARN_ON in dquot_claim_reserved_space() will be triggered) This is not easy because of complex locking order issues for example http://bugzilla.kernel.org/show_bug.cgi?id=14739 The patch introduce quota reservation field for each fs-inode (fs specific inode is used in order to prevent bloating generic vfs inode). This reservation is managed by quota code internally similar to i_blocks/i_bytes and may not be always in sync with internal fs reservation. Also perform some code rearrangement: - Unify dquot_reserve_space() and dquot_reserve_space() - Unify dquot_release_reserved_space() and dquot_free_space() - Also this patch add missing warning update to release_rsv() dquot_release_reserved_space() must call flush_warnings() as dquot_free_space() does. Changes from V3: - fix deadlock in dquota_alloc_space in journalled mode with nodelalloc Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx> --- fs/quota/dquot.c | 218 ++++++++++++++++++++++++++++--------------------- include/linux/quota.h | 5 +- 2 files changed, 127 insertions(+), 96 deletions(-) diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 39b49c4..7872f85 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -1388,6 +1388,71 @@ void vfs_dq_drop(struct inode *inode) EXPORT_SYMBOL(vfs_dq_drop); /* + * inode_reserved_space is managed internally by quota, and protected by + * i_lock similar to i_blocks+i_bytes. + */ +static qsize_t* inode_reserved_space(struct inode * inode) +{ + /* Filesystem must explicitly define it's own method in order to use + * quota reservation interface */ + BUG_ON(!inode->i_sb->dq_op->get_reserved_space); + return inode->i_sb->dq_op->get_reserved_space(inode); +} + +static void inode_add_rsv_space(struct inode *inode, qsize_t number) +{ + spin_lock(&inode->i_lock); + *inode_reserved_space(inode) += number; + spin_unlock(&inode->i_lock); +} + +static void inode_claim_rsv_space(struct inode *inode, qsize_t number) +{ + spin_lock(&inode->i_lock); + *inode_reserved_space(inode) -= number; + inode->i_blocks += number >> 9; + number &= 511; + inode->i_bytes += number; + if (inode->i_bytes >= 512) { + inode->i_blocks++; + inode->i_bytes -= 512; + } + spin_unlock(&inode->i_lock); +} + +static void inode_sub_rsv_space(struct inode *inode, qsize_t number) +{ + spin_lock(&inode->i_lock); + *inode_reserved_space(inode) -= number; + spin_unlock(&inode->i_lock); +} + +static qsize_t inode_get_rsv_space(struct inode *inode) +{ + qsize_t ret; + spin_lock(&inode->i_lock); + ret = *inode_reserved_space(inode); + spin_unlock(&inode->i_lock); + return ret; +} + +static void __inode_add_bytes(struct inode *inode, qsize_t number, int reserve) +{ + if (reserve) + inode_add_rsv_space(inode, number); + else + inode_add_bytes(inode, number); +} + +static void __inode_sub_bytes(struct inode *inode, qsize_t number, int reserve) +{ + if (reserve) + inode_sub_rsv_space(inode, number); + else + inode_sub_bytes(inode, number); +} + +/* * Following four functions update i_blocks+i_bytes fields and * quota information (together with appropriate checks) * NOTE: We absolutely rely on the fact that caller dirties @@ -1405,6 +1470,21 @@ int __dquot_alloc_space(struct inode *inode, qsize_t number, int cnt, ret = QUOTA_OK; char warntype[MAXQUOTAS]; + /* + * First test before acquiring mutex - solves deadlocks when we + * re-enter the quota code and are already holding the mutex + */ + if (IS_NOQUOTA(inode)) { + __inode_add_bytes(inode, number, reserve); + goto out; + } + + down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + if (IS_NOQUOTA(inode)) { + __inode_add_bytes(inode, number, reserve); + goto out_unlock; + } + for (cnt = 0; cnt < MAXQUOTAS; cnt++) warntype[cnt] = QUOTA_NL_NOWARN; @@ -1415,7 +1495,8 @@ int __dquot_alloc_space(struct inode *inode, qsize_t number, if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt) == NO_QUOTA) { ret = NO_QUOTA; - goto out_unlock; + spin_unlock(&dq_data_lock); + goto out_flush_warn; } } for (cnt = 0; cnt < MAXQUOTAS; cnt++) { @@ -1426,64 +1507,32 @@ int __dquot_alloc_space(struct inode *inode, qsize_t number, else dquot_incr_space(inode->i_dquot[cnt], number); } - if (!reserve) - inode_add_bytes(inode, number); -out_unlock: spin_unlock(&dq_data_lock); - flush_warnings(inode->i_dquot, warntype); - return ret; -} - -int dquot_alloc_space(struct inode *inode, qsize_t number, int warn) -{ - int cnt, ret = QUOTA_OK; - - /* - * First test before acquiring mutex - solves deadlocks when we - * re-enter the quota code and are already holding the mutex - */ - if (IS_NOQUOTA(inode)) { - inode_add_bytes(inode, number); - goto out; - } - - down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); - if (IS_NOQUOTA(inode)) { - inode_add_bytes(inode, number); - goto out_unlock; - } - - ret = __dquot_alloc_space(inode, number, warn, 0); - if (ret == NO_QUOTA) - goto out_unlock; + __inode_add_bytes(inode, number, reserve); + if (reserve) + goto out_flush_warn; /* 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]); +out_flush_warn: + flush_warnings(inode->i_dquot, warntype); out_unlock: up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); out: return ret; } + +int dquot_alloc_space(struct inode *inode, qsize_t number, int warn) +{ + return __dquot_alloc_space(inode, number, warn, 0); +} EXPORT_SYMBOL(dquot_alloc_space); int dquot_reserve_space(struct inode *inode, qsize_t number, int warn) { - int ret = QUOTA_OK; - - if (IS_NOQUOTA(inode)) - goto out; - - down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); - if (IS_NOQUOTA(inode)) - goto out_unlock; - - ret = __dquot_alloc_space(inode, number, warn, 1); -out_unlock: - up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); -out: - return ret; + return __dquot_alloc_space(inode, number, warn, 1); } EXPORT_SYMBOL(dquot_reserve_space); @@ -1540,14 +1589,14 @@ int dquot_claim_space(struct inode *inode, qsize_t number) int ret = QUOTA_OK; if (IS_NOQUOTA(inode)) { - inode_add_bytes(inode, number); + inode_claim_rsv_space(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); + inode_claim_rsv_space(inode, number); goto out; } @@ -1559,7 +1608,7 @@ int dquot_claim_space(struct inode *inode, qsize_t number) number); } /* Update inode bytes */ - inode_add_bytes(inode, number); + inode_claim_rsv_space(inode, number); spin_unlock(&dq_data_lock); /* Dirtify all the dquots - this can block when journalling */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) @@ -1572,38 +1621,9 @@ out: EXPORT_SYMBOL(dquot_claim_space); /* - * Release reserved quota space - */ -void dquot_release_reserved_space(struct inode *inode, qsize_t number) -{ - int cnt; - - 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]) - dquot_free_reserved_space(inode->i_dquot[cnt], number); - } - spin_unlock(&dq_data_lock); - -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 */ -int dquot_free_space(struct inode *inode, qsize_t number) +int __dquot_free_space(struct inode *inode, qsize_t number, int reserve) { unsigned int cnt; char warntype[MAXQUOTAS]; @@ -1612,7 +1632,7 @@ int dquot_free_space(struct inode *inode, qsize_t number) * re-enter the quota code and are already holding the mutex */ if (IS_NOQUOTA(inode)) { out_sub: - inode_sub_bytes(inode, number); + __inode_sub_bytes(inode, number, reserve); return QUOTA_OK; } @@ -1627,21 +1647,43 @@ out_sub: if (!inode->i_dquot[cnt]) continue; warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number); - dquot_decr_space(inode->i_dquot[cnt], number); + if (reserve) + dquot_free_reserved_space(inode->i_dquot[cnt], number); + else + dquot_decr_space(inode->i_dquot[cnt], number); } - inode_sub_bytes(inode, number); spin_unlock(&dq_data_lock); + __inode_sub_bytes(inode, number, reserve); + + if (reserve) + goto out_unlock; /* 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]); +out_unlock: flush_warnings(inode->i_dquot, warntype); up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); return QUOTA_OK; } + +int dquot_free_space(struct inode *inode, qsize_t number) +{ + return __dquot_free_space(inode, number, 0); +} EXPORT_SYMBOL(dquot_free_space); /* + * Release reserved quota space + */ +void dquot_release_reserved_space(struct inode *inode, qsize_t number) +{ + return (void )__dquot_free_space(inode, number, 1); + +} +EXPORT_SYMBOL(dquot_release_reserved_space); + +/* * This operation can block, but only after everything is updated */ int dquot_free_inode(const struct inode *inode, qsize_t number) @@ -1679,19 +1721,6 @@ int dquot_free_inode(const struct inode *inode, qsize_t number) EXPORT_SYMBOL(dquot_free_inode); /* - * 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); - return reserved_space; -} - -/* * Transfer the number of inode and blocks from one diskquota to an other. * * This operation can block, but only after everything is updated @@ -1734,7 +1763,7 @@ int dquot_transfer(struct inode *inode, struct iattr *iattr) } spin_lock(&dq_data_lock); cur_space = inode_get_bytes(inode); - rsv_space = dquot_get_reserved_space(inode); + rsv_space = inode_get_rsv_space(inode); space = cur_space + rsv_space; /* Build the transfer_from list and check the limits */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { @@ -1854,6 +1883,7 @@ const struct dquot_operations dquot_operations = { .write_info = dquot_commit_info, .alloc_dquot = dquot_alloc, .destroy_dquot = dquot_destroy, + }; /* diff --git a/include/linux/quota.h b/include/linux/quota.h index 78c4889..40845f1 100644 --- a/include/linux/quota.h +++ b/include/linux/quota.h @@ -313,8 +313,9 @@ struct dquot_operations { 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 */ - qsize_t (*get_reserved_space) (struct inode *); + /* get reserved quota for delayed alloc, value returned is managed by + * quota code only */ + qsize_t* (*get_reserved_space) (struct inode *); }; /* Operations handling requests from userspace */ -- 1.6.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
