// SPDX-License-Identifier: GPL-2.0 /* * Implementation of the diskquota system for the LINUX operating system. QUOTA * is implemented using the BSD system call interface as the means of * communication with the user level. This file contains the generic routines * called by the different filesystems on allocation of an inode or block. * These routines take care of the administration needed to have a consistent * diskquota tracking system. The ideas of both user and group quotas are based * on the Melbourne quota system as used on BSD derived systems. The internal * implementation is based on one of the several variants of the LINUX * inode-subsystem with added complexity of the diskquota system. * * Author: Marco van Wieringen * * Fixes: Dmitry Gorodchanin , 11 Feb 96 * * Revised list management to avoid races * -- Bill Hawes, , 9/98 * * Fixed races in dquot_transfer(), dqget() and dquot_alloc_...(). * As the consequence the locking was moved from dquot_decr_...(), * dquot_incr_...() to calling functions. * invalidate_dquots() now writes modified dquots. * Serialized quota_off() and quota_on() for mount point. * Fixed a few bugs in grow_dquots(). * Fixed deadlock in write_dquot() - we no longer account quotas on * quota files * remove_dquot_ref() moved to inode.c - it now traverses through inodes * add_dquot_ref() restarts after blocking * Added check for bogus uid and fixed check for group in quotactl. * Jan Kara, , sponsored by SuSE CR, 10-11/99 * * Used struct list_head instead of own list struct * Invalidation of referenced dquots is no longer possible * Improved free_dquots list management * Quota and i_blocks are now updated in one place to avoid races * Warnings are now delayed so we won't block in critical section * Write updated not to require dquot lock * Jan Kara, , 9/2000 * * Added dynamic quota structure allocation * Jan Kara 12/2000 * * Rewritten quota interface. Implemented new quota format and * formats registering. * Jan Kara, , 2001,2002 * * New SMP locking. * Jan Kara, , 10/2002 * * Added journalled quota support, fix lock inversion problems * Jan Kara, , 2003,2004 * * (C) Copyright 1994 - 1997 Marco van Wieringen */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "../internal.h" /* ugh */ #include /* * There are five quota SMP locks: * * dq_list_lock protects all lists with quotas and quota formats. * * dquot->dq_dqb_lock protects data from dq_dqb * * inode->i_lock protects inode->i_blocks, i_bytes and also guards * consistency of dquot->dq_dqb with inode->i_blocks, i_bytes so that * dquot_transfer() can stabilize amount it transfers * * dq_data_lock protects mem_dqinfo structures and modifications of dquot * pointers in the inode * * dq_state_lock protects modifications of quota state (on quotaon and * quotaoff) and readers who care about latest values take it as well. * * The spinlock ordering is hence: * dq_data_lock > dq_list_lock > i_lock > dquot->dq_dqb_lock, * dq_list_lock > dq_state_lock * * Note that some things (eg. sb pointer, type, id) doesn't change during * the life of the dquot structure and so needn't to be protected by a lock * * Operation accessing dquots via inode pointers are protected by dquot_srcu. * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and * synchronize_srcu(&dquot_srcu) is called after clearing pointers from * inode and before dropping dquot references to avoid use of dquots after * they are freed. dq_data_lock is used to serialize the pointer setting and * clearing operations. * Special care needs to be taken about S_NOQUOTA inode flag (marking that * inode is a quota file). Functions adding pointers from inode to dquots have * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they * have to do all pointer modifications before dropping dq_data_lock. This makes * sure they cannot race with quotaon which first sets S_NOQUOTA flag and * then drops all pointers to dquots from an inode. * * Each dquot has its dq_lock mutex. Dquot is locked when it is being read to * memory (or space for it is being allocated) on the first dqget(), when it is * being written out, and when it is being released on the last dqput(). The * allocation and release operations are serialized by the dq_lock and by * checking the use count in dquot_release(). * * Lock ordering (including related VFS locks) is the following: * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_sem */ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); EXPORT_SYMBOL(dq_data_lock); DEFINE_STATIC_SRCU(dquot_srcu); static DECLARE_WAIT_QUEUE_HEAD(dquot_ref_wq); void __quota_error(struct super_block *sb, const char *func, const char *fmt, ...) { if (printk_ratelimit()) { va_list args; struct va_format vaf; va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; printk(KERN_ERR "Quota error (device %s): %s: %pV\n", sb->s_id, func, &vaf); va_end(args); } } EXPORT_SYMBOL(__quota_error); #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING) static char *quotatypes[] = INITQFNAMES; #endif static struct quota_format_type *quota_formats; /* List of registered formats */ static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; /* SLAB cache for dquot structures */ static struct kmem_cache *dquot_cachep; int register_quota_format(struct quota_format_type *fmt) { spin_lock(&dq_list_lock); fmt->qf_next = quota_formats; quota_formats = fmt; spin_unlock(&dq_list_lock); return 0; } EXPORT_SYMBOL(register_quota_format); void unregister_quota_format(struct quota_format_type *fmt) { struct quota_format_type **actqf; spin_lock(&dq_list_lock); for (actqf = "a_formats; *actqf && *actqf != fmt; actqf = &(*actqf)->qf_next) ; if (*actqf) *actqf = (*actqf)->qf_next; spin_unlock(&dq_list_lock); } EXPORT_SYMBOL(unregister_quota_format); static struct quota_format_type *find_quota_format(int id) { struct quota_format_type *actqf; spin_lock(&dq_list_lock); for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next) ; if (!actqf || !try_module_get(actqf->qf_owner)) { int qm; spin_unlock(&dq_list_lock); for (qm = 0; module_names[qm].qm_fmt_id && module_names[qm].qm_fmt_id != id; qm++) ; if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name)) return NULL; spin_lock(&dq_list_lock); for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next) ; if (actqf && !try_module_get(actqf->qf_owner)) actqf = NULL; } spin_unlock(&dq_list_lock); return actqf; } static void put_quota_format(struct quota_format_type *fmt) { module_put(fmt->qf_owner); } /* * Dquot List Management: * The quota code uses five lists for dquot management: the inuse_list, * releasing_dquots, free_dquots, dqi_dirty_list, and dquot_hash[] array. * A single dquot structure may be on some of those lists, depending on * its current state. * * All dquots are placed to the end of inuse_list when first created, and this * list is used for invalidate operation, which must look at every dquot. * * When the last reference of a dquot is dropped, the dquot is added to * releasing_dquots. We'll then queue work item which will call * synchronize_srcu() and after that perform the final cleanup of all the * dquots on the list. Each cleaned up dquot is moved to free_dquots list. * Both releasing_dquots and free_dquots use the dq_free list_head in the dquot * struct. * * Unused and cleaned up dquots are in the free_dquots list and this list is * searched whenever we need an available dquot. Dquots are removed from the * list as soon as they are used again and dqstats.free_dquots gives the number * of dquots on the list. When dquot is invalidated it's completely released * from memory. * * Dirty dquots are added to the dqi_dirty_list of quota_info when mark * dirtied, and this list is searched when writing dirty dquots back to * quota file. Note that some filesystems do dirty dquot tracking on their * own (e.g. in a journal) and thus don't use dqi_dirty_list. * * Dquots with a specific identity (device, type and id) are placed on * one of the dquot_hash[] hash chains. The provides an efficient search * mechanism to locate a specific dquot. */ static LIST_HEAD(inuse_list); static LIST_HEAD(free_dquots); static LIST_HEAD(releasing_dquots); static unsigned int dq_hash_bits, dq_hash_mask; static struct hlist_head *dquot_hash; struct dqstats dqstats; EXPORT_SYMBOL(dqstats); static qsize_t inode_get_rsv_space(struct inode *inode); static qsize_t __inode_get_rsv_space(struct inode *inode); static int __dquot_initialize(struct inode *inode, int type); static void quota_release_workfn(struct work_struct *work); static DECLARE_DELAYED_WORK(quota_release_work, quota_release_workfn); static inline unsigned int hashfn(const struct super_block *sb, struct kqid qid) { unsigned int id = from_kqid(&init_user_ns, qid); int type = qid.type; unsigned long tmp; tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; } /* * Following list functions expect dq_list_lock to be held */ static inline void insert_dquot_hash(struct dquot *dquot) { struct hlist_head *head; head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id); hlist_add_head(&dquot->dq_hash, head); } static inline void remove_dquot_hash(struct dquot *dquot) { hlist_del_init(&dquot->dq_hash); } static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, struct kqid qid) { struct hlist_node *node; struct dquot *dquot; hlist_for_each (node, dquot_hash+hashent) { dquot = hlist_entry(node, struct dquot, dq_hash); if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid)) return dquot; } return NULL; } /* Add a dquot to the tail of the free list */ static inline void put_dquot_last(struct dquot *dquot) { list_add_tail(&dquot->dq_free, &free_dquots); dqstats_inc(DQST_FREE_DQUOTS); } static inline void put_releasing_dquots(struct dquot *dquot) { list_add_tail(&dquot->dq_free, &releasing_dquots); set_bit(DQ_RELEASING_B, &dquot->dq_flags); } static inline void remove_free_dquot(struct dquot *dquot) { if (list_empty(&dquot->dq_free)) return; list_del_init(&dquot->dq_free); if (!test_bit(DQ_RELEASING_B, &dquot->dq_flags)) dqstats_dec(DQST_FREE_DQUOTS); else clear_bit(DQ_RELEASING_B, &dquot->dq_flags); } static inline void put_inuse(struct dquot *dquot) { /* We add to the back of inuse list so we don't have to restart * when traversing this list and we block */ list_add_tail(&dquot->dq_inuse, &inuse_list); dqstats_inc(DQST_ALLOC_DQUOTS); } static inline void remove_inuse(struct dquot *dquot) { dqstats_dec(DQST_ALLOC_DQUOTS); list_del(&dquot->dq_inuse); } /* * End of list functions needing dq_list_lock */ static void wait_on_dquot(struct dquot *dquot) { mutex_lock(&dquot->dq_lock); mutex_unlock(&dquot->dq_lock); } static inline int dquot_active(struct dquot *dquot) { return test_bit(DQ_ACTIVE_B, &dquot->dq_flags); } static inline int dquot_dirty(struct dquot *dquot) { return test_bit(DQ_MOD_B, &dquot->dq_flags); } static inline int mark_dquot_dirty(struct dquot *dquot) { return dquot->dq_sb->dq_op->mark_dirty(dquot); } /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ int dquot_mark_dquot_dirty(struct dquot *dquot) { int ret = 1; if (!dquot_active(dquot)) return 0; if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags); /* If quota is dirty already, we don't have to acquire dq_list_lock */ if (dquot_dirty(dquot)) return 1; spin_lock(&dq_list_lock); if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> info[dquot->dq_id.type].dqi_dirty_list); ret = 0; } spin_unlock(&dq_list_lock); return ret; } EXPORT_SYMBOL(dquot_mark_dquot_dirty); /* Dirtify all the dquots - this can block when journalling */ static inline int mark_all_dquot_dirty(struct dquot * const *dquot) { int ret, err, cnt; ret = err = 0; for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (dquot[cnt]) /* Even in case of error we have to continue */ ret = mark_dquot_dirty(dquot[cnt]); if (!err) err = ret; } return err; } static inline void dqput_all(struct dquot **dquot) { unsigned int cnt; for (cnt = 0; cnt < MAXQUOTAS; cnt++) dqput(dquot[cnt]); } static inline int clear_dquot_dirty(struct dquot *dquot) { if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags); spin_lock(&dq_list_lock); if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) { spin_unlock(&dq_list_lock); return 0; } list_del_init(&dquot->dq_dirty); spin_unlock(&dq_list_lock); return 1; } void mark_info_dirty(struct super_block *sb, int type) { spin_lock(&dq_data_lock); sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY; spin_unlock(&dq_data_lock); } EXPORT_SYMBOL(mark_info_dirty); /* * Read dquot from disk and alloc space for it */ int dquot_acquire(struct dquot *dquot) { int ret = 0, ret2 = 0; unsigned int memalloc; struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); mutex_lock(&dquot->dq_lock); memalloc = memalloc_nofs_save(); if (!test_bit(DQ_READ_B, &dquot->dq_flags)) { ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot); if (ret < 0) goto out_iolock; } /* Make sure flags update is visible after dquot has been filled */ smp_mb__before_atomic(); set_bit(DQ_READ_B, &dquot->dq_flags); /* Instantiate dquot if needed */ if (!dquot_active(dquot) && !dquot->dq_off) { ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); /* Write the info if needed */ if (info_dirty(&dqopt->info[dquot->dq_id.type])) { ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( dquot->dq_sb, dquot->dq_id.type); } if (ret < 0) goto out_iolock; if (ret2 < 0) { ret = ret2; goto out_iolock; } } /* * Make sure flags update is visible after on-disk struct has been * allocated. Paired with smp_rmb() in dqget(). */ smp_mb__before_atomic(); set_bit(DQ_ACTIVE_B, &dquot->dq_flags); out_iolock: memalloc_nofs_restore(memalloc); mutex_unlock(&dquot->dq_lock); return ret; } EXPORT_SYMBOL(dquot_acquire); /* * Write dquot to disk */ int dquot_commit(struct dquot *dquot) { int ret = 0; unsigned int memalloc; struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); mutex_lock(&dquot->dq_lock); memalloc = memalloc_nofs_save(); if (!clear_dquot_dirty(dquot)) goto out_lock; /* Inactive dquot can be only if there was error during read/init * => we have better not writing it */ if (dquot_active(dquot)) ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); else ret = -EIO; out_lock: memalloc_nofs_restore(memalloc); mutex_unlock(&dquot->dq_lock); return ret; } EXPORT_SYMBOL(dquot_commit); /* * Release dquot */ int dquot_release(struct dquot *dquot) { int ret = 0, ret2 = 0; unsigned int memalloc; struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); mutex_lock(&dquot->dq_lock); memalloc = memalloc_nofs_save(); /* Check whether we are not racing with some other dqget() */ if (dquot_is_busy(dquot)) goto out_dqlock; if (dqopt->ops[dquot->dq_id.type]->release_dqblk) { ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot); /* Write the info */ if (info_dirty(&dqopt->info[dquot->dq_id.type])) { ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( dquot->dq_sb, dquot->dq_id.type); } if (ret >= 0) ret = ret2; } clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); out_dqlock: memalloc_nofs_restore(memalloc); mutex_unlock(&dquot->dq_lock); return ret; } EXPORT_SYMBOL(dquot_release); void dquot_destroy(struct dquot *dquot) { kmem_cache_free(dquot_cachep, dquot); } EXPORT_SYMBOL(dquot_destroy); static inline void do_destroy_dquot(struct dquot *dquot) { dquot->dq_sb->dq_op->destroy_dquot(dquot); } /* Invalidate all dquots on the list. Note that this function is called after * quota is disabled and pointers from inodes removed so there cannot be new * quota users. There can still be some users of quotas due to inodes being * just deleted or pruned by prune_icache() (those are not attached to any * list) or parallel quotactl call. We have to wait for such users. */ static void invalidate_dquots(struct super_block *sb, int type) { struct dquot *dquot, *tmp; restart: flush_delayed_work("a_release_work); spin_lock(&dq_list_lock); list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { if (dquot->dq_sb != sb) continue; if (dquot->dq_id.type != type) continue; /* Wait for dquot users */ if (atomic_read(&dquot->dq_count)) { atomic_inc(&dquot->dq_count); spin_unlock(&dq_list_lock); /* * Once dqput() wakes us up, we know it's time to free * the dquot. * IMPORTANT: we rely on the fact that there is always * at most one process waiting for dquot to free. * Otherwise dq_count would be > 1 and we would never * wake up. */ wait_event(dquot_ref_wq, atomic_read(&dquot->dq_count) == 1); dqput(dquot); /* At this moment dquot() need not exist (it could be * reclaimed by prune_dqcache(). Hence we must * restart. */ goto restart; } /* * The last user already dropped its reference but dquot didn't * get fully cleaned up yet. Restart the scan which flushes the * work cleaning up released dquots. */ if (test_bit(DQ_RELEASING_B, &dquot->dq_flags)) { spin_unlock(&dq_list_lock); goto restart; } /* * Quota now has no users and it has been written on last * dqput() */ remove_dquot_hash(dquot); remove_free_dquot(dquot); remove_inuse(dquot); do_destroy_dquot(dquot); } spin_unlock(&dq_list_lock); } /* Call callback for every active dquot on given filesystem */ int dquot_scan_active(struct super_block *sb, int (*fn)(struct dquot *dquot, unsigned long priv), unsigned long priv) { struct dquot *dquot, *old_dquot = NULL; int ret = 0; WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); spin_lock(&dq_list_lock); list_for_each_entry(dquot, &inuse_list, dq_inuse) { if (!dquot_active(dquot)) continue; if (dquot->dq_sb != sb) continue; /* Now we have active dquot so we can just increase use count */ atomic_inc(&dquot->dq_count); spin_unlock(&dq_list_lock); dqput(old_dquot); old_dquot = dquot; /* * ->release_dquot() can be racing with us. Our reference * protects us from new calls to it so just wait for any * outstanding call and recheck the DQ_ACTIVE_B after that. */ wait_on_dquot(dquot); if (dquot_active(dquot)) { ret = fn(dquot, priv); if (ret < 0) goto out; } spin_lock(&dq_list_lock); /* We are safe to continue now because our dquot could not * be moved out of the inuse list while we hold the reference */ } spin_unlock(&dq_list_lock); out: dqput(old_dquot); return ret; } EXPORT_SYMBOL(dquot_scan_active); static inline int dquot_write_dquot(struct dquot *dquot) { int ret = dquot->dq_sb->dq_op->write_dquot(dquot); if (ret < 0) { quota_error(dquot->dq_sb, "Can't write quota structure " "(error %d). Quota may get out of sync!", ret); /* Clear dirty bit anyway to avoid infinite loop. */ clear_dquot_dirty(dquot); } return ret; } /* Write all dquot structures to quota files */ int dquot_writeback_dquots(struct super_block *sb, int type) { struct list_head dirty; struct dquot *dquot; struct quota_info *dqopt = sb_dqopt(sb); int cnt; int err, ret = 0; WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (type != -1 && cnt != type) continue; if (!sb_has_quota_active(sb, cnt)) continue; spin_lock(&dq_list_lock); /* Move list away to avoid livelock. */ list_replace_init(&dqopt->info[cnt].dqi_dirty_list, &dirty); while (!list_empty(&dirty)) { dquot = list_first_entry(&dirty, struct dquot, dq_dirty); WARN_ON(!dquot_active(dquot)); /* If the dquot is releasing we should not touch it */ if (test_bit(DQ_RELEASING_B, &dquot->dq_flags)) { spin_unlock(&dq_list_lock); flush_delayed_work("a_release_work); spin_lock(&dq_list_lock); continue; } /* Now we have active dquot from which someone is * holding reference so we can safely just increase * use count */ dqgrab(dquot); spin_unlock(&dq_list_lock); err = dquot_write_dquot(dquot); if (err && !ret) ret = err; dqput(dquot); spin_lock(&dq_list_lock); } spin_unlock(&dq_list_lock); } for (cnt = 0; cnt < MAXQUOTAS; cnt++) if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) && info_dirty(&dqopt->info[cnt])) sb->dq_op->write_info(sb, cnt); dqstats_inc(DQST_SYNCS); return ret; } EXPORT_SYMBOL(dquot_writeback_dquots); /* Write all dquot structures to disk and make them visible from userspace */ int dquot_quota_sync(struct super_block *sb, int type) { struct quota_info *dqopt = sb_dqopt(sb); int cnt; int ret; ret = dquot_writeback_dquots(sb, type); if (ret) return ret; if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) return 0; /* This is not very clever (and fast) but currently I don't know about * any other simple way of getting quota data to disk and we must get * them there for userspace to be visible... */ if (sb->s_op->sync_fs) { ret = sb->s_op->sync_fs(sb, 1); if (ret) return ret; } ret = sync_blockdev(sb->s_bdev); if (ret) return ret; /* * Now when everything is written we can discard the pagecache so * that userspace sees the changes. */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (type != -1 && cnt != type) continue; if (!sb_has_quota_active(sb, cnt)) continue; inode_lock(dqopt->files[cnt]); truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); inode_unlock(dqopt->files[cnt]); } return 0; } EXPORT_SYMBOL(dquot_quota_sync); static unsigned long dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) { struct dquot *dquot; unsigned long freed = 0; spin_lock(&dq_list_lock); while (!list_empty(&free_dquots) && sc->nr_to_scan) { dquot = list_first_entry(&free_dquots, struct dquot, dq_free); remove_dquot_hash(dquot); remove_free_dquot(dquot); remove_inuse(dquot); do_destroy_dquot(dquot); sc->nr_to_scan--; freed++; } spin_unlock(&dq_list_lock); return freed; } static unsigned long dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc) { return vfs_pressure_ratio( percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])); } static struct shrinker dqcache_shrinker = { .count_objects = dqcache_shrink_count, .scan_objects = dqcache_shrink_scan, .seeks = DEFAULT_SEEKS, }; /* * Safely release dquot and put reference to dquot. */ static void quota_release_workfn(struct work_struct *work) { struct dquot *dquot; struct list_head rls_head; spin_lock(&dq_list_lock); /* Exchange the list head to avoid livelock. */ list_replace_init(&releasing_dquots, &rls_head); spin_unlock(&dq_list_lock); synchronize_srcu(&dquot_srcu); restart: spin_lock(&dq_list_lock); while (!list_empty(&rls_head)) { dquot = list_first_entry(&rls_head, struct dquot, dq_free); WARN_ON_ONCE(atomic_read(&dquot->dq_count)); /* * Note that DQ_RELEASING_B protects us from racing with * invalidate_dquots() calls so we are safe to work with the * dquot even after we drop dq_list_lock. */ if (dquot_dirty(dquot)) { spin_unlock(&dq_list_lock); /* Commit dquot before releasing */ dquot_write_dquot(dquot); goto restart; } if (dquot_active(dquot)) { spin_unlock(&dq_list_lock); dquot->dq_sb->dq_op->release_dquot(dquot); goto restart; } /* Dquot is inactive and clean, now move it to free list */ remove_free_dquot(dquot); put_dquot_last(dquot); } spin_unlock(&dq_list_lock); } /* * Put reference to dquot */ void dqput(struct dquot *dquot) { if (!dquot) return; #ifdef CONFIG_QUOTA_DEBUG if (!atomic_read(&dquot->dq_count)) { quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", quotatypes[dquot->dq_id.type], from_kqid(&init_user_ns, dquot->dq_id)); BUG(); } #endif dqstats_inc(DQST_DROPS); spin_lock(&dq_list_lock); if (atomic_read(&dquot->dq_count) > 1) { /* We have more than one user... nothing to do */ atomic_dec(&dquot->dq_count); /* Releasing dquot during quotaoff phase? */ if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) && atomic_read(&dquot->dq_count) == 1) wake_up(&dquot_ref_wq); spin_unlock(&dq_list_lock); return; } /* Need to release dquot? */ #ifdef CONFIG_QUOTA_DEBUG /* sanity check */ BUG_ON(!list_empty(&dquot->dq_free)); #endif put_releasing_dquots(dquot); atomic_dec(&dquot->dq_count); spin_unlock(&dq_list_lock); queue_delayed_work(system_unbound_wq, "a_release_work, 1); } EXPORT_SYMBOL(dqput); struct dquot *dquot_alloc(struct super_block *sb, int type) { return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); } EXPORT_SYMBOL(dquot_alloc); static struct dquot *get_empty_dquot(struct super_block *sb, int type) { struct dquot *dquot; dquot = sb->dq_op->alloc_dquot(sb, type); if(!dquot) return NULL; mutex_init(&dquot->dq_lock); INIT_LIST_HEAD(&dquot->dq_free); INIT_LIST_HEAD(&dquot->dq_inuse); INIT_HLIST_NODE(&dquot->dq_hash); INIT_LIST_HEAD(&dquot->dq_dirty); dquot->dq_sb = sb; dquot->dq_id = make_kqid_invalid(type); atomic_set(&dquot->dq_count, 1); spin_lock_init(&dquot->dq_dqb_lock); return dquot; } /* * Get reference to dquot * * Locking is slightly tricky here. We are guarded from parallel quotaoff() * destroying our dquot by: * a) checking for quota flags under dq_list_lock and * b) getting a reference to dquot before we release dq_list_lock */ struct dquot *dqget(struct super_block *sb, struct kqid qid) { unsigned int hashent = hashfn(sb, qid); struct dquot *dquot, *empty = NULL; if (!qid_has_mapping(sb->s_user_ns, qid)) return ERR_PTR(-EINVAL); if (!sb_has_quota_active(sb, qid.type)) return ERR_PTR(-ESRCH); we_slept: spin_lock(&dq_list_lock); spin_lock(&dq_state_lock); if (!sb_has_quota_active(sb, qid.type)) { spin_unlock(&dq_state_lock); spin_unlock(&dq_list_lock); dquot = ERR_PTR(-ESRCH); goto out; } spin_unlock(&dq_state_lock); dquot = find_dquot(hashent, sb, qid); if (!dquot) { if (!empty) { spin_unlock(&dq_list_lock); empty = get_empty_dquot(sb, qid.type); if (!empty) schedule(); /* Try to wait for a moment... */ goto we_slept; } dquot = empty; empty = NULL; dquot->dq_id = qid; /* all dquots go on the inuse_list */ put_inuse(dquot); /* hash it first so it can be found */ insert_dquot_hash(dquot); spin_unlock(&dq_list_lock); dqstats_inc(DQST_LOOKUPS); } else { if (!atomic_read(&dquot->dq_count)) remove_free_dquot(dquot); atomic_inc(&dquot->dq_count); spin_unlock(&dq_list_lock); dqstats_inc(DQST_CACHE_HITS); dqstats_inc(DQST_LOOKUPS); } /* Wait for dq_lock - after this we know that either dquot_release() is * already finished or it will be canceled due to dq_count > 0 test */ wait_on_dquot(dquot); /* Read the dquot / allocate space in quota file */ if (!dquot_active(dquot)) { int err; err = sb->dq_op->acquire_dquot(dquot); if (err < 0) { dqput(dquot); dquot = ERR_PTR(err); goto out; } } /* * Make sure following reads see filled structure - paired with * smp_mb__before_atomic() in dquot_acquire(). */ smp_rmb(); #ifdef CONFIG_QUOTA_DEBUG BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ #endif out: if (empty) do_destroy_dquot(empty); return dquot; } EXPORT_SYMBOL(dqget); static inline struct dquot **i_dquot(struct inode *inode) { return inode->i_sb->s_op->get_dquots(inode); } static int dqinit_needed(struct inode *inode, int type) { struct dquot * const *dquots; int cnt; if (IS_NOQUOTA(inode)) return 0; dquots = i_dquot(inode); if (type != -1) return !dquots[type]; for (cnt = 0; cnt < MAXQUOTAS; cnt++) if (!dquots[cnt]) return 1; return 0; } /* This routine is guarded by s_umount semaphore */ static int add_dquot_ref(struct super_block *sb, int type) { struct inode *inode, *old_inode = NULL; #ifdef CONFIG_QUOTA_DEBUG int reserved = 0; #endif int err = 0; spin_lock(&sb->s_inode_list_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { spin_lock(&inode->i_lock); if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || !atomic_read(&inode->i_writecount) || !dqinit_needed(inode, type)) { spin_unlock(&inode->i_lock); continue; } __iget(inode); spin_unlock(&inode->i_lock); spin_unlock(&sb->s_inode_list_lock); #ifdef CONFIG_QUOTA_DEBUG if (unlikely(inode_get_rsv_space(inode) > 0)) reserved = 1; #endif iput(old_inode); err = __dquot_initialize(inode, type); if (err) { iput(inode); goto out; } /* * We hold a reference to 'inode' so it couldn't have been * removed from s_inodes list while we dropped the * s_inode_list_lock. We cannot iput the inode now as we can be * holding the last reference and we cannot iput it under * s_inode_list_lock. So we keep the reference and iput it * later. */ old_inode = inode; cond_resched(); spin_lock(&sb->s_inode_list_lock); } spin_unlock(&sb->s_inode_list_lock); iput(old_inode); out: #ifdef CONFIG_QUOTA_DEBUG if (reserved) { quota_error(sb, "Writes happened before quota was turned on " "thus quota information is probably inconsistent. " "Please run quotacheck(8)"); } #endif return err; } /* * Remove references to dquots from inode and add dquot to list for freeing * if we have the last reference to dquot */ static void remove_inode_dquot_ref(struct inode *inode, int type, struct list_head *tofree_head) { struct dquot **dquots = i_dquot(inode); struct dquot *dquot = dquots[type]; if (!dquot) return; dquots[type] = NULL; if (list_empty(&dquot->dq_free)) { /* * The inode still has reference to dquot so it can't be in the * free list */ spin_lock(&dq_list_lock); list_add(&dquot->dq_free, tofree_head); spin_unlock(&dq_list_lock); } else { /* * Dquot is already in a list to put so we won't drop the last * reference here. */ dqput(dquot); } } /* * Free list of dquots * Dquots are removed from inodes and no new references can be got so we are * the only ones holding reference */ static void put_dquot_list(struct list_head *tofree_head) { struct list_head *act_head; struct dquot *dquot; act_head = tofree_head->next; while (act_head != tofree_head) { dquot = list_entry(act_head, struct dquot, dq_free); act_head = act_head->next; /* Remove dquot from the list so we won't have problems... */ list_del_init(&dquot->dq_free); dqput(dquot); } } static void remove_dquot_ref(struct super_block *sb, int type, struct list_head *tofree_head) { struct inode *inode; #ifdef CONFIG_QUOTA_DEBUG int reserved = 0; #endif spin_lock(&sb->s_inode_list_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { /* * We have to scan also I_NEW inodes because they can already * have quota pointer initialized. Luckily, we need to touch * only quota pointers and these have separate locking * (dq_data_lock). */ spin_lock(&dq_data_lock); if (!IS_NOQUOTA(inode)) { #ifdef CONFIG_QUOTA_DEBUG if (unlikely(inode_get_rsv_space(inode) > 0)) reserved = 1; #endif remove_inode_dquot_ref(inode, type, tofree_head); } spin_unlock(&dq_data_lock); } spin_unlock(&sb->s_inode_list_lock); #ifdef CONFIG_QUOTA_DEBUG if (reserved) { printk(KERN_WARNING "VFS (%s): Writes happened after quota" " was disabled thus quota information is probably " "inconsistent. Please run quotacheck(8).\n", sb->s_id); } #endif } /* Gather all references from inodes and drop them */ static void drop_dquot_ref(struct super_block *sb, int type) { LIST_HEAD(tofree_head); if (sb->dq_op) { remove_dquot_ref(sb, type, &tofree_head); synchronize_srcu(&dquot_srcu); put_dquot_list(&tofree_head); } } static inline void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) { if (dquot->dq_dqb.dqb_rsvspace >= number) dquot->dq_dqb.dqb_rsvspace -= number; else { WARN_ON_ONCE(1); dquot->dq_dqb.dqb_rsvspace = 0; } if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= dquot->dq_dqb.dqb_bsoftlimit) dquot->dq_dqb.dqb_btime = (time64_t) 0; clear_bit(DQ_BLKS_B, &dquot->dq_flags); } static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) { if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || dquot->dq_dqb.dqb_curinodes >= number) dquot->dq_dqb.dqb_curinodes -= number; else dquot->dq_dqb.dqb_curinodes = 0; if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) dquot->dq_dqb.dqb_itime = (time64_t) 0; clear_bit(DQ_INODES_B, &dquot->dq_flags); } static void dquot_decr_space(struct dquot *dquot, qsize_t number) { if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || dquot->dq_dqb.dqb_curspace >= number) dquot->dq_dqb.dqb_curspace -= number; else dquot->dq_dqb.dqb_curspace = 0; if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= dquot->dq_dqb.dqb_bsoftlimit) dquot->dq_dqb.dqb_btime = (time64_t) 0; clear_bit(DQ_BLKS_B, &dquot->dq_flags); } struct dquot_warn { struct super_block *w_sb; struct kqid w_dq_id; short w_type; }; static int warning_issued(struct dquot *dquot, const int warntype) { int flag = (warntype == QUOTA_NL_BHARDWARN || warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : ((warntype == QUOTA_NL_IHARDWARN || warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); if (!flag) return 0; return test_and_set_bit(flag, &dquot->dq_flags); } #ifdef CONFIG_PRINT_QUOTA_WARNING static int flag_print_warnings = 1; static int need_print_warning(struct dquot_warn *warn) { if (!flag_print_warnings) return 0; switch (warn->w_dq_id.type) { case USRQUOTA: return uid_eq(current_fsuid(), warn->w_dq_id.uid); case GRPQUOTA: return in_group_p(warn->w_dq_id.gid); case PRJQUOTA: return 1; } return 0; } /* Print warning to user which exceeded quota */ static void print_warning(struct dquot_warn *warn) { char *msg = NULL; struct tty_struct *tty; int warntype = warn->w_type; if (warntype == QUOTA_NL_IHARDBELOW || warntype == QUOTA_NL_ISOFTBELOW || warntype == QUOTA_NL_BHARDBELOW || warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) return; tty = get_current_tty(); if (!tty) return; tty_write_message(tty, warn->w_sb->s_id); if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) tty_write_message(tty, ": warning, "); else tty_write_message(tty, ": write failed, "); tty_write_message(tty, quotatypes[warn->w_dq_id.type]); switch (warntype) { case QUOTA_NL_IHARDWARN: msg = " file limit reached.\r\n"; break; case QUOTA_NL_ISOFTLONGWARN: msg = " file quota exceeded too long.\r\n"; break; case QUOTA_NL_ISOFTWARN: msg = " file quota exceeded.\r\n"; break; case QUOTA_NL_BHARDWARN: msg = " block limit reached.\r\n"; break; case QUOTA_NL_BSOFTLONGWARN: msg = " block quota exceeded too long.\r\n"; break; case QUOTA_NL_BSOFTWARN: msg = " block quota exceeded.\r\n"; break; } tty_write_message(tty, msg); tty_kref_put(tty); } #endif static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, int warntype) { if (warning_issued(dquot, warntype)) return; warn->w_type = warntype; warn->w_sb = dquot->dq_sb; warn->w_dq_id = dquot->dq_id; } /* * Write warnings to the console and send warning messages over netlink. * * Note that this function can call into tty and networking code. */ static void flush_warnings(struct dquot_warn *warn) { int i; for (i = 0; i < MAXQUOTAS; i++) { if (warn[i].w_type == QUOTA_NL_NOWARN) continue; #ifdef CONFIG_PRINT_QUOTA_WARNING print_warning(&warn[i]); #endif quota_send_warning(warn[i].w_dq_id, warn[i].w_sb->s_dev, warn[i].w_type); } } static int ignore_hardlimit(struct dquot *dquot) { struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; return capable(CAP_SYS_RESOURCE) && (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || !(info->dqi_flags & DQF_ROOT_SQUASH)); } static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes, struct dquot_warn *warn) { qsize_t newinodes; int ret = 0; spin_lock(&dquot->dq_dqb_lock); newinodes = dquot->dq_dqb.dqb_curinodes + inodes; if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || test_bit(DQ_FAKE_B, &dquot->dq_flags)) goto add; if (dquot->dq_dqb.dqb_ihardlimit && newinodes > dquot->dq_dqb.dqb_ihardlimit && !ignore_hardlimit(dquot)) { prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN); ret = -EDQUOT; goto out; } if (dquot->dq_dqb.dqb_isoftlimit && newinodes > dquot->dq_dqb.dqb_isoftlimit && dquot->dq_dqb.dqb_itime && ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime && !ignore_hardlimit(dquot)) { prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); ret = -EDQUOT; goto out; } if (dquot->dq_dqb.dqb_isoftlimit && newinodes > dquot->dq_dqb.dqb_isoftlimit && dquot->dq_dqb.dqb_itime == 0) { prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; } add: dquot->dq_dqb.dqb_curinodes = newinodes; out: spin_unlock(&dquot->dq_dqb_lock); return ret; } static int dquot_add_space(struct dquot *dquot, qsize_t space, qsize_t rsv_space, unsigned int flags, struct dquot_warn *warn) { qsize_t tspace; struct super_block *sb = dquot->dq_sb; int ret = 0; spin_lock(&dquot->dq_dqb_lock); if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || test_bit(DQ_FAKE_B, &dquot->dq_flags)) goto finish; tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace + space + rsv_space; if (dquot->dq_dqb.dqb_bhardlimit && tspace > dquot->dq_dqb.dqb_bhardlimit && !ignore_hardlimit(dquot)) { if (flags & DQUOT_SPACE_WARN) prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); ret = -EDQUOT; goto finish; } if (dquot->dq_dqb.dqb_bsoftlimit && tspace > dquot->dq_dqb.dqb_bsoftlimit && dquot->dq_dqb.dqb_btime && ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime && !ignore_hardlimit(dquot)) { if (flags & DQUOT_SPACE_WARN) prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); ret = -EDQUOT; goto finish; } if (dquot->dq_dqb.dqb_bsoftlimit && tspace > dquot->dq_dqb.dqb_bsoftlimit && dquot->dq_dqb.dqb_btime == 0) { if (flags & DQUOT_SPACE_WARN) { prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() + sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; } else { /* * We don't allow preallocation to exceed softlimit so exceeding will * be always printed */ ret = -EDQUOT; goto finish; } } finish: /* * We have to be careful and go through warning generation & grace time * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it * only here... */ if (flags & DQUOT_SPACE_NOFAIL) ret = 0; if (!ret) { dquot->dq_dqb.dqb_rsvspace += rsv_space; dquot->dq_dqb.dqb_curspace += space; } spin_unlock(&dquot->dq_dqb_lock); return ret; } static int info_idq_free(struct dquot *dquot, qsize_t inodes) { qsize_t newinodes; if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) return QUOTA_NL_NOWARN; newinodes = dquot->dq_dqb.dqb_curinodes - inodes; if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) return QUOTA_NL_ISOFTBELOW; if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && newinodes < dquot->dq_dqb.dqb_ihardlimit) return QUOTA_NL_IHARDBELOW; return QUOTA_NL_NOWARN; } static int info_bdq_free(struct dquot *dquot, qsize_t space) { qsize_t tspace; tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace; if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || tspace <= dquot->dq_dqb.dqb_bsoftlimit) return QUOTA_NL_NOWARN; if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit) return QUOTA_NL_BSOFTBELOW; if (tspace >= dquot->dq_dqb.dqb_bhardlimit && tspace - space < dquot->dq_dqb.dqb_bhardlimit) return QUOTA_NL_BHARDBELOW; return QUOTA_NL_NOWARN; } static int inode_quota_active(const struct inode *inode) { struct super_block *sb = inode->i_sb; if (IS_NOQUOTA(inode)) return 0; return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); } /* * Initialize quota pointers in inode * * It is better to call this function outside of any transaction as it * might need a lot of space in journal for dquot structure allocation. */ static int __dquot_initialize(struct inode *inode, int type) { int cnt, init_needed = 0; struct dquot **dquots, *got[MAXQUOTAS] = {}; struct super_block *sb = inode->i_sb; qsize_t rsv; int ret = 0; if (!inode_quota_active(inode)) return 0; dquots = i_dquot(inode); /* First get references to structures we might need. */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { struct kqid qid; kprojid_t projid; int rc; struct dquot *dquot; if (type != -1 && cnt != type) continue; /* * The i_dquot should have been initialized in most cases, * we check it without locking here to avoid unnecessary * dqget()/dqput() calls. */ if (dquots[cnt]) continue; if (!sb_has_quota_active(sb, cnt)) continue; init_needed = 1; switch (cnt) { case USRQUOTA: qid = make_kqid_uid(inode->i_uid); break; case GRPQUOTA: qid = make_kqid_gid(inode->i_gid); break; case PRJQUOTA: rc = inode->i_sb->dq_op->get_projid(inode, &projid); if (rc) continue; qid = make_kqid_projid(projid); break; } dquot = dqget(sb, qid); if (IS_ERR(dquot)) { /* We raced with somebody turning quotas off... */ if (PTR_ERR(dquot) != -ESRCH) { ret = PTR_ERR(dquot); goto out_put; } dquot = NULL; } got[cnt] = dquot; } /* All required i_dquot has been initialized */ if (!init_needed) return 0; spin_lock(&dq_data_lock); if (IS_NOQUOTA(inode)) goto out_lock; for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (type != -1 && cnt != type) continue; /* Avoid races with quotaoff() */ if (!sb_has_quota_active(sb, cnt)) continue; /* We could race with quotaon or dqget() could have failed */ if (!got[cnt]) continue; if (!dquots[cnt]) { dquots[cnt] = got[cnt]; got[cnt] = NULL; /* * Make quota reservation system happy if someone * did a write before quota was turned on */ rsv = inode_get_rsv_space(inode); if (unlikely(rsv)) { spin_lock(&inode->i_lock); /* Get reservation again under proper lock */ rsv = __inode_get_rsv_space(inode); spin_lock(&dquots[cnt]->dq_dqb_lock); dquots[cnt]->dq_dqb.dqb_rsvspace += rsv; spin_unlock(&dquots[cnt]->dq_dqb_lock); spin_unlock(&inode->i_lock); } } } out_lock: spin_unlock(&dq_data_lock); out_put: /* Drop unused references */ dqput_all(got); return ret; } int dquot_initialize(struct inode *inode) { return __dquot_initialize(inode, -1); } EXPORT_SYMBOL(dquot_initialize); bool dquot_initialize_needed(struct inode *inode) { struct dquot **dquots; int i; if (!inode_quota_active(inode)) return false; dquots = i_dquot(inode); for (i = 0; i < MAXQUOTAS; i++) if (!dquots[i] && sb_has_quota_active(inode->i_sb, i)) return true; return false; } EXPORT_SYMBOL(dquot_initialize_needed); /* * Release all quotas referenced by inode. * * This function only be called on inode free or converting * a file to quota file, no other users for the i_dquot in * both cases, so we needn't call synchronize_srcu() after * clearing i_dquot. */ static void __dquot_drop(struct inode *inode) { int cnt; struct dquot **dquots = i_dquot(inode); struct dquot *put[MAXQUOTAS]; spin_lock(&dq_data_lock); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { put[cnt] = dquots[cnt]; dquots[cnt] = NULL; } spin_unlock(&dq_data_lock); dqput_all(put); } void dquot_drop(struct inode *inode) { struct dquot * const *dquots; int cnt; if (IS_NOQUOTA(inode)) return; /* * Test before calling to rule out calls from proc and such * where we are not allowed to block. Note that this is * actually reliable test even without the lock - the caller * must assure that nobody can come after the DQUOT_DROP and * add quota pointers back anyway. */ dquots = i_dquot(inode); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (dquots[cnt]) break; } if (cnt < MAXQUOTAS) __dquot_drop(inode); } EXPORT_SYMBOL(dquot_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 qsize_t __inode_get_rsv_space(struct inode *inode) { if (!inode->i_sb->dq_op->get_reserved_space) return 0; return *inode_reserved_space(inode); } static qsize_t inode_get_rsv_space(struct inode *inode) { qsize_t ret; if (!inode->i_sb->dq_op->get_reserved_space) return 0; spin_lock(&inode->i_lock); ret = __inode_get_rsv_space(inode); spin_unlock(&inode->i_lock); return ret; } /* * This functions updates i_blocks+i_bytes fields and quota information * (together with appropriate checks). * * NOTE: We absolutely rely on the fact that caller dirties the inode * (usually helpers in quotaops.h care about this) and holds a handle for * the current transaction so that dquot write and inode write go into the * same transaction. */ /* * This operation can block, but only after everything is updated */ int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) { int cnt, ret = 0, index; struct dquot_warn warn[MAXQUOTAS]; int reserve = flags & DQUOT_SPACE_RESERVE; struct dquot **dquots; if (!inode_quota_active(inode)) { if (reserve) { spin_lock(&inode->i_lock); *inode_reserved_space(inode) += number; spin_unlock(&inode->i_lock); } else { inode_add_bytes(inode, number); } goto out; } for (cnt = 0; cnt < MAXQUOTAS; cnt++) warn[cnt].w_type = QUOTA_NL_NOWARN; dquots = i_dquot(inode); index = srcu_read_lock(&dquot_srcu); spin_lock(&inode->i_lock); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (!dquots[cnt]) continue; if (reserve) { ret = dquot_add_space(dquots[cnt], 0, number, flags, &warn[cnt]); } else { ret = dquot_add_space(dquots[cnt], number, 0, flags, &warn[cnt]); } if (ret) { /* Back out changes we already did */ for (cnt--; cnt >= 0; cnt--) { if (!dquots[cnt]) continue; spin_lock(&dquots[cnt]->dq_dqb_lock); if (reserve) dquot_free_reserved_space(dquots[cnt], number); else dquot_decr_space(dquots[cnt], number); spin_unlock(&dquots[cnt]->dq_dqb_lock); } spin_unlock(&inode->i_lock); goto out_flush_warn; } } if (reserve) *inode_reserved_space(inode) += number; else __inode_add_bytes(inode, number); spin_unlock(&inode->i_lock); if (reserve) goto out_flush_warn; mark_all_dquot_dirty(dquots); out_flush_warn: srcu_read_unlock(&dquot_srcu, index); flush_warnings(warn); out: return ret; } EXPORT_SYMBOL(__dquot_alloc_space); /* * This operation can block, but only after everything is updated */ int dquot_alloc_inode(struct inode *inode) { int cnt, ret = 0, index; struct dquot_warn warn[MAXQUOTAS]; struct dquot * const *dquots; if (!inode_quota_active(inode)) return 0; for (cnt = 0; cnt < MAXQUOTAS; cnt++) warn[cnt].w_type = QUOTA_NL_NOWARN; dquots = i_dquot(inode); index = srcu_read_lock(&dquot_srcu); spin_lock(&inode->i_lock); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (!dquots[cnt]) continue; ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]); if (ret) { for (cnt--; cnt >= 0; cnt--) { if (!dquots[cnt]) continue; /* Back out changes we already did */ spin_lock(&dquots[cnt]->dq_dqb_lock); dquot_decr_inodes(dquots[cnt], 1); spin_unlock(&dquots[cnt]->dq_dqb_lock); } goto warn_put_all; } } warn_put_all: spin_unlock(&inode->i_lock); if (ret == 0) mark_all_dquot_dirty(dquots); srcu_read_unlock(&dquot_srcu, index); flush_warnings(warn); return ret; } EXPORT_SYMBOL(dquot_alloc_inode); /* * Convert in-memory reserved quotas to real consumed quotas */ int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) { struct dquot **dquots; int cnt, index; if (!inode_quota_active(inode)) { spin_lock(&inode->i_lock); *inode_reserved_space(inode) -= number; __inode_add_bytes(inode, number); spin_unlock(&inode->i_lock); return 0; } dquots = i_dquot(inode); index = srcu_read_lock(&dquot_srcu); spin_lock(&inode->i_lock); /* Claim reserved quotas to allocated quotas */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (dquots[cnt]) { struct dquot *dquot = dquots[cnt]; spin_lock(&dquot->dq_dqb_lock); if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number)) number = dquot->dq_dqb.dqb_rsvspace; dquot->dq_dqb.dqb_curspace += number; dquot->dq_dqb.dqb_rsvspace -= number; spin_unlock(&dquot->dq_dqb_lock); } } /* Update inode bytes */ *inode_reserved_space(inode) -= number; __inode_add_bytes(inode, number); spin_unlock(&inode->i_lock); mark_all_dquot_dirty(dquots); srcu_read_unlock(&dquot_srcu, index); return 0; } EXPORT_SYMBOL(dquot_claim_space_nodirty); /* * Convert allocated space back to in-memory reserved quotas */ void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) { struct dquot **dquots; int cnt, index; if (!inode_quota_active(inode)) { spin_lock(&inode->i_lock); *inode_reserved_space(inode) += number; __inode_sub_bytes(inode, number); spin_unlock(&inode->i_lock); return; } dquots = i_dquot(inode); index = srcu_read_lock(&dquot_srcu); spin_lock(&inode->i_lock); /* Claim reserved quotas to allocated quotas */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (dquots[cnt]) { struct dquot *dquot = dquots[cnt]; spin_lock(&dquot->dq_dqb_lock); if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) number = dquot->dq_dqb.dqb_curspace; dquot->dq_dqb.dqb_rsvspace += number; dquot->dq_dqb.dqb_curspace -= number; spin_unlock(&dquot->dq_dqb_lock); } } /* Update inode bytes */ *inode_reserved_space(inode) += number; __inode_sub_bytes(inode, number); spin_unlock(&inode->i_lock); mark_all_dquot_dirty(dquots); srcu_read_unlock(&dquot_srcu, index); return; } EXPORT_SYMBOL(dquot_reclaim_space_nodirty); /* * This operation can block, but only after everything is updated */ void __dquot_free_space(struct inode *inode, qsize_t number, int flags) { unsigned int cnt; struct dquot_warn warn[MAXQUOTAS]; struct dquot **dquots; int reserve = flags & DQUOT_SPACE_RESERVE, index; if (!inode_quota_active(inode)) { if (reserve) { spin_lock(&inode->i_lock); *inode_reserved_space(inode) -= number; spin_unlock(&inode->i_lock); } else { inode_sub_bytes(inode, number); } return; } dquots = i_dquot(inode); index = srcu_read_lock(&dquot_srcu); spin_lock(&inode->i_lock); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { int wtype; warn[cnt].w_type = QUOTA_NL_NOWARN; if (!dquots[cnt]) continue; spin_lock(&dquots[cnt]->dq_dqb_lock); wtype = info_bdq_free(dquots[cnt], number); if (wtype != QUOTA_NL_NOWARN) prepare_warning(&warn[cnt], dquots[cnt], wtype); if (reserve) dquot_free_reserved_space(dquots[cnt], number); else dquot_decr_space(dquots[cnt], number); spin_unlock(&dquots[cnt]->dq_dqb_lock); } if (reserve) *inode_reserved_space(inode) -= number; else __inode_sub_bytes(inode, number); spin_unlock(&inode->i_lock); if (reserve) goto out_unlock; mark_all_dquot_dirty(dquots); out_unlock: srcu_read_unlock(&dquot_srcu, index); flush_warnings(warn); } EXPORT_SYMBOL(__dquot_free_space); /* * This operation can block, but only after everything is updated */ void dquot_free_inode(struct inode *inode) { unsigned int cnt; struct dquot_warn warn[MAXQUOTAS]; struct dquot * const *dquots; int index; if (!inode_quota_active(inode)) return; dquots = i_dquot(inode); index = srcu_read_lock(&dquot_srcu); spin_lock(&inode->i_lock); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { int wtype; warn[cnt].w_type = QUOTA_NL_NOWARN; if (!dquots[cnt]) continue; spin_lock(&dquots[cnt]->dq_dqb_lock); wtype = info_idq_free(dquots[cnt], 1); if (wtype != QUOTA_NL_NOWARN) prepare_warning(&warn[cnt], dquots[cnt], wtype); dquot_decr_inodes(dquots[cnt], 1); spin_unlock(&dquots[cnt]->dq_dqb_lock); } spin_unlock(&inode->i_lock); mark_all_dquot_dirty(dquots); srcu_read_unlock(&dquot_srcu, index); flush_warnings(warn); } EXPORT_SYMBOL(dquot_free_inode); /* * Transfer the number of inode and blocks from one diskquota to an other. * On success, dquot references in transfer_to are consumed and references * to original dquots that need to be released are placed there. On failure, * references are kept untouched. * * This operation can block, but only after everything is updated * A transaction must be started when entering this function. * * We are holding reference on transfer_from & transfer_to, no need to * protect them by srcu_read_lock(). */ int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) { qsize_t cur_space; qsize_t rsv_space = 0; qsize_t inode_usage = 1; struct dquot *transfer_from[MAXQUOTAS] = {}; int cnt, ret = 0; char is_valid[MAXQUOTAS] = {}; struct dquot_warn warn_to[MAXQUOTAS]; struct dquot_warn warn_from_inodes[MAXQUOTAS]; struct dquot_warn warn_from_space[MAXQUOTAS]; if (IS_NOQUOTA(inode)) return 0; if (inode->i_sb->dq_op->get_inode_usage) { ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage); if (ret) return ret; } /* Initialize the arrays */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { warn_to[cnt].w_type = QUOTA_NL_NOWARN; warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; } spin_lock(&dq_data_lock); spin_lock(&inode->i_lock); if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ spin_unlock(&inode->i_lock); spin_unlock(&dq_data_lock); return 0; } cur_space = __inode_get_bytes(inode); rsv_space = __inode_get_rsv_space(inode); /* * Build the transfer_from list, check limits, and update usage in * the target structures. */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { /* * Skip changes for same uid or gid or for turned off quota-type. */ if (!transfer_to[cnt]) continue; /* Avoid races with quotaoff() */ if (!sb_has_quota_active(inode->i_sb, cnt)) continue; is_valid[cnt] = 1; transfer_from[cnt] = i_dquot(inode)[cnt]; ret = dquot_add_inodes(transfer_to[cnt], inode_usage, &warn_to[cnt]); if (ret) goto over_quota; ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, DQUOT_SPACE_WARN, &warn_to[cnt]); if (ret) { spin_lock(&transfer_to[cnt]->dq_dqb_lock); dquot_decr_inodes(transfer_to[cnt], inode_usage); spin_unlock(&transfer_to[cnt]->dq_dqb_lock); goto over_quota; } } /* Decrease usage for source structures and update quota pointers */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (!is_valid[cnt]) continue; /* Due to IO error we might not have transfer_from[] structure */ if (transfer_from[cnt]) { int wtype; spin_lock(&transfer_from[cnt]->dq_dqb_lock); wtype = info_idq_free(transfer_from[cnt], inode_usage); if (wtype != QUOTA_NL_NOWARN) prepare_warning(&warn_from_inodes[cnt], transfer_from[cnt], wtype); wtype = info_bdq_free(transfer_from[cnt], cur_space + rsv_space); if (wtype != QUOTA_NL_NOWARN) prepare_warning(&warn_from_space[cnt], transfer_from[cnt], wtype); dquot_decr_inodes(transfer_from[cnt], inode_usage); dquot_decr_space(transfer_from[cnt], cur_space); dquot_free_reserved_space(transfer_from[cnt], rsv_space); spin_unlock(&transfer_from[cnt]->dq_dqb_lock); } i_dquot(inode)[cnt] = transfer_to[cnt]; } spin_unlock(&inode->i_lock); spin_unlock(&dq_data_lock); mark_all_dquot_dirty(transfer_from); mark_all_dquot_dirty(transfer_to); flush_warnings(warn_to); flush_warnings(warn_from_inodes); flush_warnings(warn_from_space); /* Pass back references to put */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) if (is_valid[cnt]) transfer_to[cnt] = transfer_from[cnt]; return 0; over_quota: /* Back out changes we already did */ for (cnt--; cnt >= 0; cnt--) { if (!is_valid[cnt]) continue; spin_lock(&transfer_to[cnt]->dq_dqb_lock); dquot_decr_inodes(transfer_to[cnt], inode_usage); dquot_decr_space(transfer_to[cnt], cur_space); dquot_free_reserved_space(transfer_to[cnt], rsv_space); spin_unlock(&transfer_to[cnt]->dq_dqb_lock); } spin_unlock(&inode->i_lock); spin_unlock(&dq_data_lock); flush_warnings(warn_to); return ret; } EXPORT_SYMBOL(__dquot_transfer); /* Wrapper for transferring ownership of an inode for uid/gid only * Called from FSXXX_setattr() */ int dquot_transfer(struct inode *inode, struct iattr *iattr) { struct dquot *transfer_to[MAXQUOTAS] = {}; struct dquot *dquot; struct super_block *sb = inode->i_sb; int ret; if (!inode_quota_active(inode)) return 0; if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){ dquot = dqget(sb, make_kqid_uid(iattr->ia_uid)); if (IS_ERR(dquot)) { if (PTR_ERR(dquot) != -ESRCH) { ret = PTR_ERR(dquot); goto out_put; } dquot = NULL; } transfer_to[USRQUOTA] = dquot; } if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){ dquot = dqget(sb, make_kqid_gid(iattr->ia_gid)); if (IS_ERR(dquot)) { if (PTR_ERR(dquot) != -ESRCH) { ret = PTR_ERR(dquot); goto out_put; } dquot = NULL; } transfer_to[GRPQUOTA] = dquot; } ret = __dquot_transfer(inode, transfer_to); out_put: dqput_all(transfer_to); return ret; } EXPORT_SYMBOL(dquot_transfer); /* * Write info of quota file to disk */ int dquot_commit_info(struct super_block *sb, int type) { struct quota_info *dqopt = sb_dqopt(sb); return dqopt->ops[type]->write_file_info(sb, type); } EXPORT_SYMBOL(dquot_commit_info); int dquot_get_next_id(struct super_block *sb, struct kqid *qid) { struct quota_info *dqopt = sb_dqopt(sb); if (!sb_has_quota_active(sb, qid->type)) return -ESRCH; if (!dqopt->ops[qid->type]->get_next_id) return -ENOSYS; return dqopt->ops[qid->type]->get_next_id(sb, qid); } EXPORT_SYMBOL(dquot_get_next_id); /* * Definitions of diskquota operations. */ const struct dquot_operations dquot_operations = { .write_dquot = dquot_commit, .acquire_dquot = dquot_acquire, .release_dquot = dquot_release, .mark_dirty = dquot_mark_dquot_dirty, .write_info = dquot_commit_info, .alloc_dquot = dquot_alloc, .destroy_dquot = dquot_destroy, .get_next_id = dquot_get_next_id, }; EXPORT_SYMBOL(dquot_operations); /* * Generic helper for ->open on filesystems supporting disk quotas. */ int dquot_file_open(struct inode *inode, struct file *file) { int error; error = generic_file_open(inode, file); if (!error && (file->f_mode & FMODE_WRITE)) error = dquot_initialize(inode); return error; } EXPORT_SYMBOL(dquot_file_open); static void vfs_cleanup_quota_inode(struct super_block *sb, int type) { struct quota_info *dqopt = sb_dqopt(sb); struct inode *inode = dqopt->files[type]; if (!inode) return; if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { inode_lock(inode); inode->i_flags &= ~S_NOQUOTA; inode_unlock(inode); } dqopt->files[type] = NULL; iput(inode); } /* * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) */ int dquot_disable(struct super_block *sb, int type, unsigned int flags) { int cnt; struct quota_info *dqopt = sb_dqopt(sb); /* s_umount should be held in exclusive mode */ if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) up_read(&sb->s_umount); /* Cannot turn off usage accounting without turning off limits, or * suspend quotas and simultaneously turn quotas off. */ if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | DQUOT_USAGE_ENABLED))) return -EINVAL; /* * Skip everything if there's nothing to do. We have to do this because * sometimes we are called when fill_super() failed and calling * sync_fs() in such cases does no good. */ if (!sb_any_quota_loaded(sb)) return 0; for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (type != -1 && cnt != type) continue; if (!sb_has_quota_loaded(sb, cnt)) continue; if (flags & DQUOT_SUSPENDED) { spin_lock(&dq_state_lock); dqopt->flags |= dquot_state_flag(DQUOT_SUSPENDED, cnt); spin_unlock(&dq_state_lock); } else { spin_lock(&dq_state_lock); dqopt->flags &= ~dquot_state_flag(flags, cnt); /* Turning off suspended quotas? */ if (!sb_has_quota_loaded(sb, cnt) && sb_has_quota_suspended(sb, cnt)) { dqopt->flags &= ~dquot_state_flag( DQUOT_SUSPENDED, cnt); spin_unlock(&dq_state_lock); vfs_cleanup_quota_inode(sb, cnt); continue; } spin_unlock(&dq_state_lock); } /* We still have to keep quota loaded? */ if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) continue; /* Note: these are blocking operations */ drop_dquot_ref(sb, cnt); invalidate_dquots(sb, cnt); /* * Now all dquots should be invalidated, all writes done so we * should be only users of the info. No locks needed. */ if (info_dirty(&dqopt->info[cnt])) sb->dq_op->write_info(sb, cnt); if (dqopt->ops[cnt]->free_file_info) dqopt->ops[cnt]->free_file_info(sb, cnt); put_quota_format(dqopt->info[cnt].dqi_format); dqopt->info[cnt].dqi_flags = 0; dqopt->info[cnt].dqi_igrace = 0; dqopt->info[cnt].dqi_bgrace = 0; dqopt->ops[cnt] = NULL; } /* Skip syncing and setting flags if quota files are hidden */ if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) goto put_inodes; /* Sync the superblock so that buffers with quota data are written to * disk (and so userspace sees correct data afterwards). */ if (sb->s_op->sync_fs) sb->s_op->sync_fs(sb, 1); sync_blockdev(sb->s_bdev); /* Now the quota files are just ordinary files and we can set the * inode flags back. Moreover we discard the pagecache so that * userspace sees the writes we did bypassing the pagecache. We * must also discard the blockdev buffers so that we see the * changes done by userspace on the next quotaon() */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) if (!sb_has_quota_loaded(sb, cnt) && dqopt->files[cnt]) { inode_lock(dqopt->files[cnt]); truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); inode_unlock(dqopt->files[cnt]); } if (sb->s_bdev) invalidate_bdev(sb->s_bdev); put_inodes: /* We are done when suspending quotas */ if (flags & DQUOT_SUSPENDED) return 0; for (cnt = 0; cnt < MAXQUOTAS; cnt++) if (!sb_has_quota_loaded(sb, cnt)) vfs_cleanup_quota_inode(sb, cnt); return 0; } EXPORT_SYMBOL(dquot_disable); int dquot_quota_off(struct super_block *sb, int type) { return dquot_disable(sb, type, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); } EXPORT_SYMBOL(dquot_quota_off); /* * Turn quotas on on a device */ static int vfs_setup_quota_inode(struct inode *inode, int type) { struct super_block *sb = inode->i_sb; struct quota_info *dqopt = sb_dqopt(sb); if (is_bad_inode(inode)) return -EUCLEAN; if (!S_ISREG(inode->i_mode)) return -EACCES; if (IS_RDONLY(inode)) return -EROFS; if (sb_has_quota_loaded(sb, type)) return -EBUSY; /* * Quota files should never be encrypted. They should be thought of as * filesystem metadata, not user data. New-style internal quota files * cannot be encrypted by users anyway, but old-style external quota * files could potentially be incorrectly created in an encrypted * directory, hence this explicit check. Some reasons why encrypted * quota files don't work include: (1) some filesystems that support * encryption don't handle it in their quota_read and quota_write, and * (2) cleaning up encrypted quota files at unmount would need special * consideration, as quota files are cleaned up later than user files. */ if (IS_ENCRYPTED(inode)) return -EINVAL; dqopt->files[type] = igrab(inode); if (!dqopt->files[type]) return -EIO; if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { /* We don't want quota and atime on quota files (deadlocks * possible) Also nobody should write to the file - we use * special IO operations which ignore the immutable bit. */ inode_lock(inode); inode->i_flags |= S_NOQUOTA; inode_unlock(inode); /* * When S_NOQUOTA is set, remove dquot references as no more * references can be added */ __dquot_drop(inode); } return 0; } int dquot_load_quota_sb(struct super_block *sb, int type, int format_id, unsigned int flags) { struct quota_format_type *fmt = find_quota_format(format_id); struct quota_info *dqopt = sb_dqopt(sb); int error; /* Just unsuspend quotas? */ BUG_ON(flags & DQUOT_SUSPENDED); /* s_umount should be held in exclusive mode */ if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) up_read(&sb->s_umount); if (!fmt) return -ESRCH; if (!sb->s_op->quota_write || !sb->s_op->quota_read || (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { error = -EINVAL; goto out_fmt; } /* Filesystems outside of init_user_ns not yet supported */ if (sb->s_user_ns != &init_user_ns) { error = -EINVAL; goto out_fmt; } /* Usage always has to be set... */ if (!(flags & DQUOT_USAGE_ENABLED)) { error = -EINVAL; goto out_fmt; } if (sb_has_quota_loaded(sb, type)) { error = -EBUSY; goto out_fmt; } if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { /* As we bypass the pagecache we must now flush all the * dirty data and invalidate caches so that kernel sees * changes from userspace. It is not enough to just flush * the quota file since if blocksize < pagesize, invalidation * of the cache could fail because of other unrelated dirty * data */ sync_filesystem(sb); invalidate_bdev(sb->s_bdev); } error = -EINVAL; if (!fmt->qf_ops->check_quota_file(sb, type)) goto out_fmt; dqopt->ops[type] = fmt->qf_ops; dqopt->info[type].dqi_format = fmt; dqopt->info[type].dqi_fmt_id = format_id; INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); error = dqopt->ops[type]->read_file_info(sb, type); if (error < 0) goto out_fmt; if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { spin_lock(&dq_data_lock); dqopt->info[type].dqi_flags |= DQF_SYS_FILE; spin_unlock(&dq_data_lock); } spin_lock(&dq_state_lock); dqopt->flags |= dquot_state_flag(flags, type); spin_unlock(&dq_state_lock); error = add_dquot_ref(sb, type); if (error) dquot_disable(sb, type, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); return error; out_fmt: put_quota_format(fmt); return error; } EXPORT_SYMBOL(dquot_load_quota_sb); /* * More powerful function for turning on quotas on given quota inode allowing * setting of individual quota flags */ int dquot_load_quota_inode(struct inode *inode, int type, int format_id, unsigned int flags) { int err; err = vfs_setup_quota_inode(inode, type); if (err < 0) return err; err = dquot_load_quota_sb(inode->i_sb, type, format_id, flags); if (err < 0) vfs_cleanup_quota_inode(inode->i_sb, type); return err; } EXPORT_SYMBOL(dquot_load_quota_inode); /* Reenable quotas on remount RW */ int dquot_resume(struct super_block *sb, int type) { struct quota_info *dqopt = sb_dqopt(sb); int ret = 0, cnt; unsigned int flags; /* s_umount should be held in exclusive mode */ if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) up_read(&sb->s_umount); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (type != -1 && cnt != type) continue; if (!sb_has_quota_suspended(sb, cnt)) continue; spin_lock(&dq_state_lock); flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED, cnt); dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); spin_unlock(&dq_state_lock); flags = dquot_generic_flag(flags, cnt); ret = dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id, flags); if (ret < 0) vfs_cleanup_quota_inode(sb, cnt); } return ret; } EXPORT_SYMBOL(dquot_resume); int dquot_quota_on(struct super_block *sb, int type, int format_id, const struct path *path) { int error = security_quota_on(path->dentry); if (error) return error; /* Quota file not on the same filesystem? */ if (path->dentry->d_sb != sb) error = -EXDEV; else error = dquot_load_quota_inode(d_inode(path->dentry), type, format_id, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); return error; } EXPORT_SYMBOL(dquot_quota_on); /* * This function is used when filesystem needs to initialize quotas * during mount time. */ int dquot_quota_on_mount(struct super_block *sb, char *qf_name, int format_id, int type) { struct dentry *dentry; int error; dentry = lookup_positive_unlocked(qf_name, sb->s_root, strlen(qf_name)); if (IS_ERR(dentry)) return PTR_ERR(dentry); error = security_quota_on(dentry); if (!error) error = dquot_load_quota_inode(d_inode(dentry), type, format_id, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); dput(dentry); return error; } EXPORT_SYMBOL(dquot_quota_on_mount); static int dquot_quota_enable(struct super_block *sb, unsigned int flags) { int ret; int type; struct quota_info *dqopt = sb_dqopt(sb); if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) return -ENOSYS; /* Accounting cannot be turned on while fs is mounted */ flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); if (!flags) return -EINVAL; for (type = 0; type < MAXQUOTAS; type++) { if (!(flags & qtype_enforce_flag(type))) continue; /* Can't enforce without accounting */ if (!sb_has_quota_usage_enabled(sb, type)) { ret = -EINVAL; goto out_err; } if (sb_has_quota_limits_enabled(sb, type)) { ret = -EBUSY; goto out_err; } spin_lock(&dq_state_lock); dqopt->flags |= dquot_state_flag(DQUOT_LIMITS_ENABLED, type); spin_unlock(&dq_state_lock); } return 0; out_err: /* Backout enforcement enablement we already did */ for (type--; type >= 0; type--) { if (flags & qtype_enforce_flag(type)) dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); } /* Error code translation for better compatibility with XFS */ if (ret == -EBUSY) ret = -EEXIST; return ret; } static int dquot_quota_disable(struct super_block *sb, unsigned int flags) { int ret; int type; struct quota_info *dqopt = sb_dqopt(sb); if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) return -ENOSYS; /* * We don't support turning off accounting via quotactl. In principle * quota infrastructure can do this but filesystems don't expect * userspace to be able to do it. */ if (flags & (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) return -EOPNOTSUPP; /* Filter out limits not enabled */ for (type = 0; type < MAXQUOTAS; type++) if (!sb_has_quota_limits_enabled(sb, type)) flags &= ~qtype_enforce_flag(type); /* Nothing left? */ if (!flags) return -EEXIST; for (type = 0; type < MAXQUOTAS; type++) { if (flags & qtype_enforce_flag(type)) { ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); if (ret < 0) goto out_err; } } return 0; out_err: /* Backout enforcement disabling we already did */ for (type--; type >= 0; type--) { if (flags & qtype_enforce_flag(type)) { spin_lock(&dq_state_lock); dqopt->flags |= dquot_state_flag(DQUOT_LIMITS_ENABLED, type); spin_unlock(&dq_state_lock); } } return ret; } /* Generic routine for getting common part of quota structure */ static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) { struct mem_dqblk *dm = &dquot->dq_dqb; memset(di, 0, sizeof(*di)); spin_lock(&dquot->dq_dqb_lock); di->d_spc_hardlimit = dm->dqb_bhardlimit; di->d_spc_softlimit = dm->dqb_bsoftlimit; di->d_ino_hardlimit = dm->dqb_ihardlimit; di->d_ino_softlimit = dm->dqb_isoftlimit; di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; di->d_ino_count = dm->dqb_curinodes; di->d_spc_timer = dm->dqb_btime; di->d_ino_timer = dm->dqb_itime; spin_unlock(&dquot->dq_dqb_lock); } int dquot_get_dqblk(struct super_block *sb, struct kqid qid, struct qc_dqblk *di) { struct dquot *dquot; dquot = dqget(sb, qid); if (IS_ERR(dquot)) return PTR_ERR(dquot); do_get_dqblk(dquot, di); dqput(dquot); return 0; } EXPORT_SYMBOL(dquot_get_dqblk); int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid, struct qc_dqblk *di) { struct dquot *dquot; int err; if (!sb->dq_op->get_next_id) return -ENOSYS; err = sb->dq_op->get_next_id(sb, qid); if (err < 0) return err; dquot = dqget(sb, *qid); if (IS_ERR(dquot)) return PTR_ERR(dquot); do_get_dqblk(dquot, di); dqput(dquot); return 0; } EXPORT_SYMBOL(dquot_get_next_dqblk); #define VFS_QC_MASK \ (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ QC_SPC_TIMER | QC_INO_TIMER) /* Generic routine for setting common part of quota structure */ static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) { struct mem_dqblk *dm = &dquot->dq_dqb; int check_blim = 0, check_ilim = 0; struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; if (di->d_fieldmask & ~VFS_QC_MASK) return -EINVAL; if (((di->d_fieldmask & QC_SPC_SOFT) && di->d_spc_softlimit > dqi->dqi_max_spc_limit) || ((di->d_fieldmask & QC_SPC_HARD) && di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || ((di->d_fieldmask & QC_INO_SOFT) && (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || ((di->d_fieldmask & QC_INO_HARD) && (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) return -ERANGE; spin_lock(&dquot->dq_dqb_lock); if (di->d_fieldmask & QC_SPACE) { dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; check_blim = 1; set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); } if (di->d_fieldmask & QC_SPC_SOFT) dm->dqb_bsoftlimit = di->d_spc_softlimit; if (di->d_fieldmask & QC_SPC_HARD) dm->dqb_bhardlimit = di->d_spc_hardlimit; if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { check_blim = 1; set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); } if (di->d_fieldmask & QC_INO_COUNT) { dm->dqb_curinodes = di->d_ino_count; check_ilim = 1; set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); } if (di->d_fieldmask & QC_INO_SOFT) dm->dqb_isoftlimit = di->d_ino_softlimit; if (di->d_fieldmask & QC_INO_HARD) dm->dqb_ihardlimit = di->d_ino_hardlimit; if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { check_ilim = 1; set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); } if (di->d_fieldmask & QC_SPC_TIMER) { dm->dqb_btime = di->d_spc_timer; check_blim = 1; set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); } if (di->d_fieldmask & QC_INO_TIMER) { dm->dqb_itime = di->d_ino_timer; check_ilim = 1; set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); } if (check_blim) { if (!dm->dqb_bsoftlimit || dm->dqb_curspace + dm->dqb_rsvspace <= dm->dqb_bsoftlimit) { dm->dqb_btime = 0; clear_bit(DQ_BLKS_B, &dquot->dq_flags); } else if (!(di->d_fieldmask & QC_SPC_TIMER)) /* Set grace only if user hasn't provided his own... */ dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace; } if (check_ilim) { if (!dm->dqb_isoftlimit || dm->dqb_curinodes <= dm->dqb_isoftlimit) { dm->dqb_itime = 0; clear_bit(DQ_INODES_B, &dquot->dq_flags); } else if (!(di->d_fieldmask & QC_INO_TIMER)) /* Set grace only if user hasn't provided his own... */ dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace; } if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit) clear_bit(DQ_FAKE_B, &dquot->dq_flags); else set_bit(DQ_FAKE_B, &dquot->dq_flags); spin_unlock(&dquot->dq_dqb_lock); mark_dquot_dirty(dquot); return 0; } int dquot_set_dqblk(struct super_block *sb, struct kqid qid, struct qc_dqblk *di) { struct dquot *dquot; int rc; dquot = dqget(sb, qid); if (IS_ERR(dquot)) { rc = PTR_ERR(dquot); goto out; } rc = do_set_dqblk(dquot, di); dqput(dquot); out: return rc; } EXPORT_SYMBOL(dquot_set_dqblk); /* Generic routine for getting common part of quota file information */ int dquot_get_state(struct super_block *sb, struct qc_state *state) { struct mem_dqinfo *mi; struct qc_type_state *tstate; struct quota_info *dqopt = sb_dqopt(sb); int type; memset(state, 0, sizeof(*state)); for (type = 0; type < MAXQUOTAS; type++) { if (!sb_has_quota_active(sb, type)) continue; tstate = state->s_state + type; mi = sb_dqopt(sb)->info + type; tstate->flags = QCI_ACCT_ENABLED; spin_lock(&dq_data_lock); if (mi->dqi_flags & DQF_SYS_FILE) tstate->flags |= QCI_SYSFILE; if (mi->dqi_flags & DQF_ROOT_SQUASH) tstate->flags |= QCI_ROOT_SQUASH; if (sb_has_quota_limits_enabled(sb, type)) tstate->flags |= QCI_LIMITS_ENFORCED; tstate->spc_timelimit = mi->dqi_bgrace; tstate->ino_timelimit = mi->dqi_igrace; if (dqopt->files[type]) { tstate->ino = dqopt->files[type]->i_ino; tstate->blocks = dqopt->files[type]->i_blocks; } tstate->nextents = 1; /* We don't know... */ spin_unlock(&dq_data_lock); } return 0; } EXPORT_SYMBOL(dquot_get_state); /* Generic routine for setting common part of quota file information */ int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) { struct mem_dqinfo *mi; int err = 0; if ((ii->i_fieldmask & QC_WARNS_MASK) || (ii->i_fieldmask & QC_RT_SPC_TIMER)) return -EINVAL; if (!sb_has_quota_active(sb, type)) return -ESRCH; mi = sb_dqopt(sb)->info + type; if (ii->i_fieldmask & QC_FLAGS) { if ((ii->i_flags & QCI_ROOT_SQUASH && mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) return -EINVAL; } spin_lock(&dq_data_lock); if (ii->i_fieldmask & QC_SPC_TIMER) mi->dqi_bgrace = ii->i_spc_timelimit; if (ii->i_fieldmask & QC_INO_TIMER) mi->dqi_igrace = ii->i_ino_timelimit; if (ii->i_fieldmask & QC_FLAGS) { if (ii->i_flags & QCI_ROOT_SQUASH) mi->dqi_flags |= DQF_ROOT_SQUASH; else mi->dqi_flags &= ~DQF_ROOT_SQUASH; } spin_unlock(&dq_data_lock); mark_info_dirty(sb, type); /* Force write to disk */ sb->dq_op->write_info(sb, type); return err; } EXPORT_SYMBOL(dquot_set_dqinfo); const struct quotactl_ops dquot_quotactl_sysfile_ops = { .quota_enable = dquot_quota_enable, .quota_disable = dquot_quota_disable, .quota_sync = dquot_quota_sync, .get_state = dquot_get_state, .set_info = dquot_set_dqinfo, .get_dqblk = dquot_get_dqblk, .get_nextdqblk = dquot_get_next_dqblk, .set_dqblk = dquot_set_dqblk }; EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); static int do_proc_dqstats(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { unsigned int type = (unsigned long *)table->data - dqstats.stat; s64 value = percpu_counter_sum(&dqstats.counter[type]); /* Filter negative values for non-monotonic counters */ if (value < 0 && (type == DQST_ALLOC_DQUOTS || type == DQST_FREE_DQUOTS)) value = 0; /* Update global table */ dqstats.stat[type] = value; return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); } static struct ctl_table fs_dqstats_table[] = { { .procname = "lookups", .data = &dqstats.stat[DQST_LOOKUPS], .maxlen = sizeof(unsigned long), .mode = 0444, .proc_handler = do_proc_dqstats, }, { .procname = "drops", .data = &dqstats.stat[DQST_DROPS], .maxlen = sizeof(unsigned long), .mode = 0444, .proc_handler = do_proc_dqstats, }, { .procname = "reads", .data = &dqstats.stat[DQST_READS], .maxlen = sizeof(unsigned long), .mode = 0444, .proc_handler = do_proc_dqstats, }, { .procname = "writes", .data = &dqstats.stat[DQST_WRITES], .maxlen = sizeof(unsigned long), .mode = 0444, .proc_handler = do_proc_dqstats, }, { .procname = "cache_hits", .data = &dqstats.stat[DQST_CACHE_HITS], .maxlen = sizeof(unsigned long), .mode = 0444, .proc_handler = do_proc_dqstats, }, { .procname = "allocated_dquots", .data = &dqstats.stat[DQST_ALLOC_DQUOTS], .maxlen = sizeof(unsigned long), .mode = 0444, .proc_handler = do_proc_dqstats, }, { .procname = "free_dquots", .data = &dqstats.stat[DQST_FREE_DQUOTS], .maxlen = sizeof(unsigned long), .mode = 0444, .proc_handler = do_proc_dqstats, }, { .procname = "syncs", .data = &dqstats.stat[DQST_SYNCS], .maxlen = sizeof(unsigned long), .mode = 0444, .proc_handler = do_proc_dqstats, }, #ifdef CONFIG_PRINT_QUOTA_WARNING { .procname = "warnings", .data = &flag_print_warnings, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif { }, }; static struct ctl_table fs_table[] = { { .procname = "quota", .mode = 0555, .child = fs_dqstats_table, }, { }, }; static struct ctl_table sys_table[] = { { .procname = "fs", .mode = 0555, .child = fs_table, }, { }, }; static int __init dquot_init(void) { int i, ret; unsigned long nr_hash, order; printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); register_sysctl_table(sys_table); dquot_cachep = kmem_cache_create("dquot", sizeof(struct dquot), sizeof(unsigned long) * 4, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| SLAB_MEM_SPREAD|SLAB_PANIC), NULL); order = 0; dquot_hash = (struct hlist_head *)__get_free_pages(GFP_KERNEL, order); if (!dquot_hash) panic("Cannot create dquot hash table"); for (i = 0; i < _DQST_DQSTAT_LAST; i++) { ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); if (ret) panic("Cannot create dquot stat counters"); } /* Find power-of-two hlist_heads which can fit into allocation */ nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); dq_hash_bits = ilog2(nr_hash); nr_hash = 1UL << dq_hash_bits; dq_hash_mask = nr_hash - 1; for (i = 0; i < nr_hash; i++) INIT_HLIST_HEAD(dquot_hash + i); pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); if (register_shrinker(&dqcache_shrinker)) panic("Cannot register dquot shrinker"); return 0; } fs_initcall(dquot_init);