/* * 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. Currently only the * ext2 filesystem has support for disk quotas. Other filesystems may * be added in the future. 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. * * Version: $Id: dquot.c,v 6.3 1996/11/17 18:35:34 mvw Exp mvw $ * * 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 * * (C) Copyright 1994 - 1997 Marco van Wieringen */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static char *quotatypes[] = INITQFNAMES; static struct quota_format_type *quota_formats; /* List of registered formats */ int register_quota_format(struct quota_format_type *fmt) { lock_kernel(); fmt->qf_next = quota_formats; quota_formats = fmt; unlock_kernel(); return 0; } void unregister_quota_format(struct quota_format_type *fmt) { struct quota_format_type **actqf; lock_kernel(); for (actqf = "a_formats; *actqf && *actqf != fmt; actqf = &(*actqf)->qf_next); if (*actqf) *actqf = (*actqf)->qf_next; unlock_kernel(); } static struct quota_format_type *find_quota_format(int id) { struct quota_format_type *actqf; lock_kernel(); for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next); if (actqf && !try_inc_mod_count(actqf->qf_owner)) actqf = NULL; unlock_kernel(); return actqf; } static void put_quota_format(struct quota_format_type *fmt) { if (fmt->qf_owner) __MOD_DEC_USE_COUNT(fmt->qf_owner); } /* * Dquot List Management: * The quota code uses three lists for dquot management: the inuse_list, * free_dquots, and dquot_hash[] array. A single dquot structure may be * on all three 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 the sync and invalidate operations, which must look * at every dquot. * * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, * 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. * * 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. */ /* * Note that any operation which operates on dquot data (ie. dq_dqb) mustn't * block while it's updating/reading it. Otherwise races would occur. * * Locked dquots might not be referenced in inodes - operations like * add_dquot_space() does dqduplicate() and would complain. Currently * dquot it locked only once in its existence - when it's being read * to memory on first dqget() and at that time it can't be referenced * from inode. Write operations on dquots don't hold dquot lock as they * copy data to internal buffers before writing anyway and copying as well * as any data update should be atomic. Also nobody can change used * entries in dquot structure as this is done only when quota is destroyed * and invalidate_dquots() waits for dquot to have dq_count == 0. */ static LIST_HEAD(inuse_list); static LIST_HEAD(free_dquots); static struct list_head dquot_hash[NR_DQHASH]; static void dqput(struct dquot *); static struct dquot *dqduplicate(struct dquot *); static inline void get_dquot_ref(struct dquot *dquot) { dquot->dq_count++; } static inline void put_dquot_ref(struct dquot *dquot) { dquot->dq_count--; } static inline void get_dquot_dup_ref(struct dquot *dquot) { dquot->dq_dup_ref++; } static inline void put_dquot_dup_ref(struct dquot *dquot) { dquot->dq_dup_ref--; } static inline int const hashfn(struct super_block *sb, unsigned int id, int type) { return((HASHDEV(sb->s_dev) ^ id) * (MAXQUOTAS - type)) % NR_DQHASH; } static inline void insert_dquot_hash(struct dquot *dquot) { struct list_head *head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type); list_add(&dquot->dq_hash, head); } static inline void remove_dquot_hash(struct dquot *dquot) { list_del(&dquot->dq_hash); INIT_LIST_HEAD(&dquot->dq_hash); } static inline struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, unsigned int id, int type) { struct list_head *head; struct dquot *dquot; for (head = dquot_hash[hashent].next; head != dquot_hash+hashent; head = head->next) { dquot = list_entry(head, struct dquot, dq_hash); if (dquot->dq_sb == sb && dquot->dq_id == id && dquot->dq_type == type) return dquot; } return NODQUOT; } /* Add a dquot to the head of the free list */ static inline void put_dquot_head(struct dquot *dquot) { list_add(&dquot->dq_free, &free_dquots); dqstats.free_dquots++; } /* Add a dquot to the tail of the free list */ static inline void put_dquot_last(struct dquot *dquot) { list_add(&dquot->dq_free, free_dquots.prev); dqstats.free_dquots++; } /* Move dquot to the head of free list (it must be already on it) */ static inline void move_dquot_head(struct dquot *dquot) { list_del(&dquot->dq_free); list_add(&dquot->dq_free, &free_dquots); } static inline void remove_free_dquot(struct dquot *dquot) { if (list_empty(&dquot->dq_free)) return; list_del(&dquot->dq_free); INIT_LIST_HEAD(&dquot->dq_free); dqstats.free_dquots--; } 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(&dquot->dq_inuse, inuse_list.prev); dqstats.allocated_dquots++; } static inline void remove_inuse(struct dquot *dquot) { dqstats.allocated_dquots--; list_del(&dquot->dq_inuse); } static void __wait_on_dquot(struct dquot *dquot) { DECLARE_WAITQUEUE(wait, current); add_wait_queue(&dquot->dq_wait_lock, &wait); repeat: set_current_state(TASK_UNINTERRUPTIBLE); if (dquot->dq_flags & DQ_LOCKED) { schedule(); goto repeat; } remove_wait_queue(&dquot->dq_wait_lock, &wait); current->state = TASK_RUNNING; } static inline void wait_on_dquot(struct dquot *dquot) { if (dquot->dq_flags & DQ_LOCKED) __wait_on_dquot(dquot); } static inline void lock_dquot(struct dquot *dquot) { wait_on_dquot(dquot); dquot->dq_flags |= DQ_LOCKED; } static inline void unlock_dquot(struct dquot *dquot) { dquot->dq_flags &= ~DQ_LOCKED; wake_up(&dquot->dq_wait_lock); } /* Wait for dquot to be unused */ static void __wait_dquot_unused(struct dquot *dquot) { DECLARE_WAITQUEUE(wait, current); add_wait_queue(&dquot->dq_wait_free, &wait); repeat: set_current_state(TASK_UNINTERRUPTIBLE); if (dquot->dq_count) { schedule(); goto repeat; } remove_wait_queue(&dquot->dq_wait_free, &wait); current->state = TASK_RUNNING; } /* Wait for all duplicated dquot references to be dropped */ static void __wait_dup_drop(struct dquot *dquot) { DECLARE_WAITQUEUE(wait, current); add_wait_queue(&dquot->dq_wait_free, &wait); repeat: set_current_state(TASK_UNINTERRUPTIBLE); if (dquot->dq_dup_ref) { schedule(); goto repeat; } remove_wait_queue(&dquot->dq_wait_free, &wait); current->state = TASK_RUNNING; } static int read_dqblk(struct dquot *dquot) { int ret; struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); lock_dquot(dquot); down(&dqopt->dqio_sem); ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot); up(&dqopt->dqio_sem); unlock_dquot(dquot); return ret; } static int commit_dqblk(struct dquot *dquot) { int ret; struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); down(&dqopt->dqio_sem); ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); up(&dqopt->dqio_sem); return ret; } /* Invalidate all dquots on the list, wait for all users. Note that this function is called * after quota is disabled so no new quota might be created. As we only insert to the end of * inuse list, we don't have to restart searching... */ static void invalidate_dquots(struct super_block *sb, int type) { struct dquot *dquot; struct list_head *head; restart: list_for_each(head, &inuse_list) { dquot = list_entry(head, struct dquot, dq_inuse); if (dquot->dq_sb != sb) continue; if (dquot->dq_type != type) continue; dquot->dq_flags |= DQ_INVAL; if (dquot->dq_count) /* * Wait for any users of quota. As we have already cleared the flags in * superblock and cleared all pointers from inodes we are assured * that there will be no new users of this quota. */ __wait_dquot_unused(dquot); /* Quota now have no users and it has been written on last dqput() */ remove_dquot_hash(dquot); remove_free_dquot(dquot); remove_inuse(dquot); kmem_cache_free(dquot_cachep, dquot); goto restart; } } static int vfs_quota_sync(struct super_block *sb, int type) { struct list_head *head; struct dquot *dquot; struct quota_info *dqopt = sb_dqopt(sb); int cnt; restart: list_for_each(head, &inuse_list) { dquot = list_entry(head, struct dquot, dq_inuse); if (sb && dquot->dq_sb != sb) continue; if (type != -1 && dquot->dq_type != type) continue; if (!dquot->dq_sb) /* Invalidated? */ continue; if (!dquot_dirty(dquot) && !(dquot->dq_flags & DQ_LOCKED)) continue; /* Get reference to quota so it won't be invalidated. get_dquot_ref() * is enough since if dquot is locked/modified it can't be * on the free list */ get_dquot_ref(dquot); dqstats.lookups++; if (dquot->dq_flags & DQ_LOCKED) wait_on_dquot(dquot); if (dquot_dirty(dquot)) sb->dq_op->write_dquot(dquot); /* Move the inuse_list head pointer to just after the * current dquot, so that we'll restart the list walk * after this point on the next pass. */ list_move(&inuse_list, &dquot->dq_inuse); dqput(dquot); goto restart; } for (cnt = 0; cnt < MAXQUOTAS; cnt++) if ((cnt == type || type == -1) && sb_has_quota_enabled(sb, cnt)) dqopt->info[cnt].dqi_flags &= ~DQF_ANY_DQUOT_DIRTY; for (cnt = 0; cnt < MAXQUOTAS; cnt++) if ((cnt == type || type == -1) && sb_has_quota_enabled(sb, cnt) && info_dirty(&dqopt->info[cnt])) dqopt->ops[cnt]->write_file_info(sb, cnt); dqstats.syncs++; return 0; } static struct super_block *get_super_to_sync(int type) { struct list_head *head; int cnt, dirty; restart: spin_lock(&sb_lock); list_for_each(head, &super_blocks) { struct super_block *sb = list_entry(head, struct super_block, s_list); for (cnt = 0, dirty = 0; cnt < MAXQUOTAS; cnt++) if ((type == cnt || type == -1) && sb_has_quota_enabled(sb, cnt) && sb_dqopt(sb)->info[cnt].dqi_flags & DQF_ANY_DQUOT_DIRTY) dirty = 1; if (!dirty) continue; sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); if (!sb->s_root) { drop_super(sb); goto restart; } return sb; } spin_unlock(&sb_lock); return NULL; } void sync_dquots_dev(kdev_t dev, int type) { struct super_block *sb; if (dev) { if ((sb = get_super(dev))) { lock_kernel(); if (sb->s_qcop->quota_sync) sb->s_qcop->quota_sync(sb, type); unlock_kernel(); drop_super(sb); } } else { while ((sb = get_super_to_sync(type))) { lock_kernel(); if (sb->s_qcop->quota_sync) sb->s_qcop->quota_sync(sb, type); unlock_kernel(); drop_super(sb); } } } void sync_dquots_sb(struct super_block *sb, int type) { lock_kernel(); if (sb->s_qcop->quota_sync) sb->s_qcop->quota_sync(sb, type); unlock_kernel(); } /* Free unused dquots from cache */ static void prune_dqcache(int count) { struct list_head *head; struct dquot *dquot; head = free_dquots.prev; while (head != &free_dquots && count) { dquot = list_entry(head, struct dquot, dq_free); remove_dquot_hash(dquot); remove_free_dquot(dquot); remove_inuse(dquot); kmem_cache_free(dquot_cachep, dquot); count--; head = free_dquots.prev; } } /* * This is called from kswapd when we think we need some * more memory, but aren't really sure how much. So we * carefully try to free a _bit_ of our dqcache, but not * too much. * * Priority: * 1 - very urgent: shrink everything * ... * 6 - base-level: try to shrink a bit. */ int shrink_dqcache_memory(int priority, unsigned int gfp_mask) { int count = 0; lock_kernel(); count = dqstats.free_dquots / priority; prune_dqcache(count); unlock_kernel(); return kmem_cache_shrink(dquot_cachep); } /* * Put reference to dquot * NOTE: If you change this function please check whether dqput_blocks() works right... */ static void dqput(struct dquot *dquot) { if (!dquot) return; #ifdef __DQUOT_PARANOIA if (!dquot->dq_count) { printk("VFS: dqput: trying to free free dquot\n"); printk("VFS: device %s, dquot of %s %d\n", kdevname(dquot->dq_dev), quotatypes[dquot->dq_type], dquot->dq_id); return; } #endif dqstats.drops++; we_slept: if (dquot->dq_dup_ref && dquot->dq_count - dquot->dq_dup_ref <= 1) { /* Last unduplicated reference? */ __wait_dup_drop(dquot); goto we_slept; } if (dquot->dq_count > 1) { /* We have more than one user... We can simply decrement use count */ put_dquot_ref(dquot); return; } if (dquot_dirty(dquot)) { dquot->dq_sb->dq_op->write_dquot(dquot); goto we_slept; } /* sanity check */ if (!list_empty(&dquot->dq_free)) { printk(KERN_ERR "dqput: dquot already on free list??\n"); put_dquot_ref(dquot); return; } put_dquot_ref(dquot); /* If dquot is going to be invalidated invalidate_dquots() is going to free it so */ if (!(dquot->dq_flags & DQ_INVAL)) put_dquot_last(dquot); /* Place at end of LRU free queue */ wake_up(&dquot->dq_wait_free); } static struct dquot *get_empty_dquot(struct super_block *sb, int type) { struct dquot *dquot; dquot = kmem_cache_alloc(dquot_cachep, SLAB_KERNEL); if(!dquot) return NODQUOT; memset((caddr_t)dquot, 0, sizeof(struct dquot)); init_waitqueue_head(&dquot->dq_wait_free); init_waitqueue_head(&dquot->dq_wait_lock); INIT_LIST_HEAD(&dquot->dq_free); INIT_LIST_HEAD(&dquot->dq_inuse); INIT_LIST_HEAD(&dquot->dq_hash); dquot->dq_sb = sb; dquot->dq_dev = sb->s_dev; dquot->dq_type = type; dquot->dq_count = 1; /* all dquots go on the inuse_list */ put_inuse(dquot); return dquot; } static struct dquot *dqget(struct super_block *sb, unsigned int id, int type) { unsigned int hashent = hashfn(sb, id, type); struct dquot *dquot, *empty = NODQUOT; struct quota_info *dqopt = sb_dqopt(sb); we_slept: if (!is_enabled(dqopt, type)) { if (empty) dqput(empty); return NODQUOT; } if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) { if (empty == NODQUOT) { if ((empty = get_empty_dquot(sb, type)) == NODQUOT) schedule(); /* Try to wait for a moment... */ goto we_slept; } dquot = empty; dquot->dq_id = id; /* hash it first so it can be found */ insert_dquot_hash(dquot); read_dqblk(dquot); } else { if (!dquot->dq_count) remove_free_dquot(dquot); get_dquot_ref(dquot); dqstats.cache_hits++; wait_on_dquot(dquot); if (empty) dqput(empty); } if (!dquot->dq_sb) { /* Has somebody invalidated entry under us? */ printk(KERN_ERR "VFS: dqget(): Quota invalidated in dqget()!\n"); dqput(dquot); return NODQUOT; } dqstats.lookups++; return dquot; } /* Duplicate reference to dquot got from inode */ static struct dquot *dqduplicate(struct dquot *dquot) { if (dquot == NODQUOT) return NODQUOT; get_dquot_ref(dquot); if (!dquot->dq_sb) { printk(KERN_ERR "VFS: dqduplicate(): Invalidated quota to be duplicated!\n"); put_dquot_ref(dquot); return NODQUOT; } if (dquot->dq_flags & DQ_LOCKED) printk(KERN_ERR "VFS: dqduplicate(): Locked quota to be duplicated!\n"); get_dquot_dup_ref(dquot); dqstats.lookups++; return dquot; } /* Put duplicated reference */ static void dqputduplicate(struct dquot *dquot) { if (!dquot->dq_dup_ref) { printk(KERN_ERR "VFS: dqputduplicate(): Duplicated dquot put without duplicate reference.\n"); return; } put_dquot_dup_ref(dquot); if (!dquot->dq_dup_ref) wake_up(&dquot->dq_wait_free); put_dquot_ref(dquot); dqstats.drops++; } static int dqinit_needed(struct inode *inode, int type) { int cnt; if (IS_NOQUOTA(inode)) return 0; if (type != -1) return inode->i_dquot[type] == NODQUOT; for (cnt = 0; cnt < MAXQUOTAS; cnt++) if (inode->i_dquot[cnt] == NODQUOT) return 1; return 0; } static void add_dquot_ref(struct super_block *sb, int type) { struct list_head *p; restart: file_list_lock(); list_for_each(p, &sb->s_files) { struct file *filp = list_entry(p, struct file, f_list); struct inode *inode = filp->f_dentry->d_inode; if (filp->f_mode & FMODE_WRITE && dqinit_needed(inode, type)) { struct vfsmount *mnt = mntget(filp->f_vfsmnt); struct dentry *dentry = dget(filp->f_dentry); file_list_unlock(); sb->dq_op->initialize(inode, type); dput(dentry); mntput(mnt); /* As we may have blocked we had better restart... */ goto restart; } } file_list_unlock(); } /* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */ static inline int dqput_blocks(struct dquot *dquot) { if (dquot->dq_dup_ref && dquot->dq_count - dquot->dq_dup_ref <= 1) return 1; if (dquot->dq_count <= 1 && dquot->dq_flags & DQ_MOD) return 1; return 0; } /* Remove references to dquots from inode - add dquot to list for freeing if needed */ int remove_inode_dquot_ref(struct inode *inode, int type, struct list_head *tofree_head) { struct dquot *dquot = inode->i_dquot[type]; int cnt; inode->i_dquot[type] = NODQUOT; /* any other quota in use? */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (inode->i_dquot[cnt] != NODQUOT) goto put_it; } inode->i_flags &= ~S_QUOTA; put_it: if (dquot != NODQUOT) { if (dqput_blocks(dquot)) { if (dquot->dq_count != 1) printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", dquot->dq_count); list_add(&dquot->dq_free, tofree_head); /* As dquot must have currently users it can't be on the free list... */ return 1; } else dqput(dquot); /* We have guaranteed we won't block */ } return 0; } /* Free list of dquots - called from inode.c */ void put_dquot_list(struct list_head *tofree_head) { struct list_head *act_head; struct dquot *dquot; lock_kernel(); act_head = tofree_head->next; /* So now we have dquots on the list... Just free them */ while (act_head != tofree_head) { dquot = list_entry(act_head, struct dquot, dq_free); act_head = act_head->next; list_del(&dquot->dq_free); /* Remove dquot from the list so we won't have problems... */ INIT_LIST_HEAD(&dquot->dq_free); dqput(dquot); } unlock_kernel(); } static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number) { dquot->dq_dqb.dqb_curinodes += number; mark_dquot_dirty(dquot); } static inline void dquot_incr_space(struct dquot *dquot, qsize_t number) { dquot->dq_dqb.dqb_curspace += number; mark_dquot_dirty(dquot); } static inline void dquot_decr_inodes(struct dquot *dquot, unsigned long number) { if (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 = (time_t) 0; dquot->dq_flags &= ~DQ_INODES; mark_dquot_dirty(dquot); } static inline void dquot_decr_space(struct dquot *dquot, qsize_t number) { if (dquot->dq_dqb.dqb_curspace > number) dquot->dq_dqb.dqb_curspace -= number; else dquot->dq_dqb.dqb_curspace = 0; if (toqb(dquot->dq_dqb.dqb_curspace) < dquot->dq_dqb.dqb_bsoftlimit) dquot->dq_dqb.dqb_btime = (time_t) 0; dquot->dq_flags &= ~DQ_BLKS; mark_dquot_dirty(dquot); } static int flag_print_warnings = 1; static inline int need_print_warning(struct dquot *dquot, int flag) { if (!flag_print_warnings) return 0; switch (dquot->dq_type) { case USRQUOTA: return current->fsuid == dquot->dq_id && !(dquot->dq_flags & flag); case GRPQUOTA: return in_group_p(dquot->dq_id) && !(dquot->dq_flags & flag); } return 0; } /* Values of warnings */ #define NOWARN 0 #define IHARDWARN 1 #define ISOFTLONGWARN 2 #define ISOFTWARN 3 #define BHARDWARN 4 #define BSOFTLONGWARN 5 #define BSOFTWARN 6 /* Print warning to user which exceeded quota */ static void print_warning(struct dquot *dquot, const char warntype) { char *msg = NULL; int flag = (warntype == BHARDWARN || warntype == BSOFTLONGWARN) ? DQ_BLKS : ((warntype == IHARDWARN || warntype == ISOFTLONGWARN) ? DQ_INODES : 0); if (!need_print_warning(dquot, flag)) return; dquot->dq_flags |= flag; tty_write_message(current->tty, (char *)bdevname(dquot->dq_sb->s_dev)); if (warntype == ISOFTWARN || warntype == BSOFTWARN) tty_write_message(current->tty, ": warning, "); else tty_write_message(current->tty, ": write failed, "); tty_write_message(current->tty, quotatypes[dquot->dq_type]); switch (warntype) { case IHARDWARN: msg = " file limit reached.\r\n"; break; case ISOFTLONGWARN: msg = " file quota exceeded too long.\r\n"; break; case ISOFTWARN: msg = " file quota exceeded.\r\n"; break; case BHARDWARN: msg = " block limit reached.\r\n"; break; case BSOFTLONGWARN: msg = " block quota exceeded too long.\r\n"; break; case BSOFTWARN: msg = " block quota exceeded.\r\n"; break; } tty_write_message(current->tty, msg); } static inline void flush_warnings(struct dquot **dquots, char *warntype) { int i; for (i = 0; i < MAXQUOTAS; i++) if (dquots[i] != NODQUOT && warntype[i] != NOWARN) print_warning(dquots[i], warntype[i]); } static inline char ignore_hardlimit(struct dquot *dquot) { struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; return capable(CAP_SYS_RESOURCE) && (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || !(info->dqi_flags & V1_DQF_RSQUASH)); } static int check_idq(struct dquot *dquot, ulong inodes, char *warntype) { *warntype = NOWARN; if (inodes <= 0 || dquot->dq_flags & DQ_FAKE) return QUOTA_OK; if (dquot->dq_dqb.dqb_ihardlimit && (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit && !ignore_hardlimit(dquot)) { *warntype = IHARDWARN; return NO_QUOTA; } if (dquot->dq_dqb.dqb_isoftlimit && (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit && dquot->dq_dqb.dqb_itime && CURRENT_TIME >= dquot->dq_dqb.dqb_itime && !ignore_hardlimit(dquot)) { *warntype = ISOFTLONGWARN; return NO_QUOTA; } if (dquot->dq_dqb.dqb_isoftlimit && (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit && dquot->dq_dqb.dqb_itime == 0) { *warntype = ISOFTWARN; dquot->dq_dqb.dqb_itime = CURRENT_TIME + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; } return QUOTA_OK; } static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype) { *warntype = 0; if (space <= 0 || dquot->dq_flags & DQ_FAKE) return QUOTA_OK; if (dquot->dq_dqb.dqb_bhardlimit && toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bhardlimit && !ignore_hardlimit(dquot)) { if (!prealloc) *warntype = BHARDWARN; return NO_QUOTA; } if (dquot->dq_dqb.dqb_bsoftlimit && toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit && dquot->dq_dqb.dqb_btime && CURRENT_TIME >= dquot->dq_dqb.dqb_btime && !ignore_hardlimit(dquot)) { if (!prealloc) *warntype = BSOFTLONGWARN; return NO_QUOTA; } if (dquot->dq_dqb.dqb_bsoftlimit && toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit && dquot->dq_dqb.dqb_btime == 0) { if (!prealloc) { *warntype = BSOFTWARN; dquot->dq_dqb.dqb_btime = CURRENT_TIME + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace; } else /* * We don't allow preallocation to exceed softlimit so exceeding will * be always printed */ return NO_QUOTA; } return QUOTA_OK; } /* * Externally referenced functions through dquot_operations in inode. * * Note: this is a blocking operation. */ void dquot_initialize(struct inode *inode, int type) { struct dquot *dquot[MAXQUOTAS]; unsigned int id = 0; int cnt; if (IS_NOQUOTA(inode)) return; /* Build list of quotas to initialize... We can block here */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { dquot[cnt] = NODQUOT; if (type != -1 && cnt != type) continue; if (!sb_has_quota_enabled(inode->i_sb, cnt)) continue; if (inode->i_dquot[cnt] == NODQUOT) { switch (cnt) { case USRQUOTA: id = inode->i_uid; break; case GRPQUOTA: id = inode->i_gid; break; } dquot[cnt] = dqget(inode->i_sb, id, cnt); } } /* NOBLOCK START: Here we shouldn't block */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (dquot[cnt] == NODQUOT || !sb_has_quota_enabled(inode->i_sb, cnt) || inode->i_dquot[cnt] != NODQUOT) continue; inode->i_dquot[cnt] = dquot[cnt]; dquot[cnt] = NODQUOT; inode->i_flags |= S_QUOTA; } /* NOBLOCK END */ /* Put quotas which we didn't use */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) if (dquot[cnt] != NODQUOT) dqput(dquot[cnt]); } /* * Release all quota for the specified inode. * * Note: this is a blocking operation. */ void dquot_drop(struct inode *inode) { struct dquot *dquot; int cnt; inode->i_flags &= ~S_QUOTA; for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (inode->i_dquot[cnt] == NODQUOT) continue; dquot = inode->i_dquot[cnt]; inode->i_dquot[cnt] = NODQUOT; dqput(dquot); } } /* * This operation can block, but only after everything is updated */ int dquot_alloc_space(struct inode *inode, qsize_t number, int warn) { int cnt, ret = NO_QUOTA; struct dquot *dquot[MAXQUOTAS]; char warntype[MAXQUOTAS]; for (cnt = 0; cnt < MAXQUOTAS; cnt++) { dquot[cnt] = NODQUOT; warntype[cnt] = NOWARN; } /* NOBLOCK Start */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { dquot[cnt] = dqduplicate(inode->i_dquot[cnt]); if (dquot[cnt] == NODQUOT) continue; if (check_bdq(dquot[cnt], number, warn, warntype+cnt) == NO_QUOTA) goto warn_put_all; } for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (dquot[cnt] == NODQUOT) continue; dquot_incr_space(dquot[cnt], number); } inode_add_bytes(inode, number); /* NOBLOCK End */ ret = QUOTA_OK; warn_put_all: flush_warnings(dquot, warntype); for (cnt = 0; cnt < MAXQUOTAS; cnt++) if (dquot[cnt] != NODQUOT) dqputduplicate(dquot[cnt]); return ret; } /* * This operation can block, but only after everything is updated */ int dquot_alloc_inode(const struct inode *inode, unsigned long number) { int cnt, ret = NO_QUOTA; struct dquot *dquot[MAXQUOTAS]; char warntype[MAXQUOTAS]; for (cnt = 0; cnt < MAXQUOTAS; cnt++) { dquot[cnt] = NODQUOT; warntype[cnt] = NOWARN; } /* NOBLOCK Start */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { dquot[cnt] = dqduplicate(inode -> i_dquot[cnt]); if (dquot[cnt] == NODQUOT) continue; if (check_idq(dquot[cnt], number, warntype+cnt) == NO_QUOTA) goto warn_put_all; } for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (dquot[cnt] == NODQUOT) continue; dquot_incr_inodes(dquot[cnt], number); } /* NOBLOCK End */ ret = QUOTA_OK; warn_put_all: flush_warnings(dquot, warntype); for (cnt = 0; cnt < MAXQUOTAS; cnt++) if (dquot[cnt] != NODQUOT) dqputduplicate(dquot[cnt]); return ret; } /* * This is a non-blocking operation. */ void dquot_free_space(struct inode *inode, qsize_t number) { unsigned int cnt; struct dquot *dquot; /* NOBLOCK Start */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { dquot = dqduplicate(inode->i_dquot[cnt]); if (dquot == NODQUOT) continue; dquot_decr_space(dquot, number); dqputduplicate(dquot); } inode_sub_bytes(inode, number); /* NOBLOCK End */ } /* * This is a non-blocking operation. */ void dquot_free_inode(const struct inode *inode, unsigned long number) { unsigned int cnt; struct dquot *dquot; /* NOBLOCK Start */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { dquot = dqduplicate(inode->i_dquot[cnt]); if (dquot == NODQUOT) continue; dquot_decr_inodes(dquot, number); dqputduplicate(dquot); } /* NOBLOCK End */ } /* * Transfer the number of inode and blocks from one diskquota to an other. * * This operation can block, but only after everything is updated */ int dquot_transfer(struct inode *inode, struct iattr *iattr) { qsize_t space; struct dquot *transfer_from[MAXQUOTAS]; struct dquot *transfer_to[MAXQUOTAS]; int cnt, ret = NO_QUOTA, chuid = (iattr->ia_valid & ATTR_UID) && inode->i_uid != iattr->ia_uid, chgid = (iattr->ia_valid & ATTR_GID) && inode->i_gid != iattr->ia_gid; char warntype[MAXQUOTAS]; /* Clear the arrays */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { transfer_to[cnt] = transfer_from[cnt] = NODQUOT; warntype[cnt] = NOWARN; } /* First build the transfer_to list - here we can block on reading of dquots... */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (!sb_has_quota_enabled(inode->i_sb, cnt)) continue; switch (cnt) { case USRQUOTA: if (!chuid) continue; transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_uid, cnt); break; case GRPQUOTA: if (!chgid) continue; transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_gid, cnt); break; } } /* NOBLOCK START: From now on we shouldn't block */ space = inode_get_bytes(inode); /* Build the transfer_from list and check the limits */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { /* The second test can fail when quotaoff is in progress... */ if (transfer_to[cnt] == NODQUOT || !sb_has_quota_enabled(inode->i_sb, cnt)) continue; transfer_from[cnt] = dqduplicate(inode->i_dquot[cnt]); if (transfer_from[cnt] == NODQUOT) /* Can happen on quotafiles (quota isn't initialized on them)... */ continue; if (check_idq(transfer_to[cnt], 1, warntype+cnt) == NO_QUOTA || check_bdq(transfer_to[cnt], space, 0, warntype+cnt) == NO_QUOTA) goto warn_put_all; } /* * Finally perform the needed transfer from transfer_from to transfer_to */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { /* * Skip changes for same uid or gid or for non-existing quota-type. */ if (transfer_from[cnt] == NODQUOT || transfer_to[cnt] == NODQUOT) continue; dquot_decr_inodes(transfer_from[cnt], 1); dquot_decr_space(transfer_from[cnt], space); dquot_incr_inodes(transfer_to[cnt], 1); dquot_incr_space(transfer_to[cnt], space); if (inode->i_dquot[cnt] == NODQUOT) BUG(); inode->i_dquot[cnt] = transfer_to[cnt]; /* * We've got to release transfer_from[] twice - once for dquot_transfer() and * once for inode. We don't want to release transfer_to[] as it's now placed in inode */ transfer_to[cnt] = transfer_from[cnt]; } /* NOBLOCK END. From now on we can block as we wish */ ret = QUOTA_OK; warn_put_all: flush_warnings(transfer_to, warntype); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { /* First we must put duplicate - otherwise we might deadlock */ if (transfer_from[cnt] != NODQUOT) dqputduplicate(transfer_from[cnt]); if (transfer_to[cnt] != NODQUOT) dqput(transfer_to[cnt]); } return ret; } /* * Definitions of diskquota operations. */ struct dquot_operations dquot_operations = { initialize: dquot_initialize, /* mandatory */ drop: dquot_drop, /* mandatory */ alloc_space: dquot_alloc_space, alloc_inode: dquot_alloc_inode, free_space: dquot_free_space, free_inode: dquot_free_inode, transfer: dquot_transfer, write_dquot: commit_dqblk }; /* Function used by filesystems for initializing the dquot_operations structure */ void init_dquot_operations(struct dquot_operations *fsdqops) { memcpy(fsdqops, &dquot_operations, sizeof(dquot_operations)); } static inline void set_enable_flags(struct quota_info *dqopt, int type) { switch (type) { case USRQUOTA: dqopt->flags |= DQUOT_USR_ENABLED; break; case GRPQUOTA: dqopt->flags |= DQUOT_GRP_ENABLED; break; } } static inline void reset_enable_flags(struct quota_info *dqopt, int type) { switch (type) { case USRQUOTA: dqopt->flags &= ~DQUOT_USR_ENABLED; break; case GRPQUOTA: dqopt->flags &= ~DQUOT_GRP_ENABLED; break; } } /* Function in inode.c - remove pointers to dquots in icache */ extern void remove_dquot_ref(struct super_block *, int); /* * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) */ int vfs_quota_off(struct super_block *sb, int type) { int cnt; struct quota_info *dqopt = sb_dqopt(sb); lock_kernel(); if (!sb) goto out; /* We need to serialize quota_off() for device */ down(&dqopt->dqoff_sem); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (type != -1 && cnt != type) continue; if (!is_enabled(dqopt, cnt)) continue; reset_enable_flags(dqopt, cnt); /* Note: these are blocking operations */ remove_dquot_ref(sb, cnt); invalidate_dquots(sb, cnt); if (info_dirty(&dqopt->info[cnt])) dqopt->ops[cnt]->write_file_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); fput(dqopt->files[cnt]); dqopt->files[cnt] = (struct file *)NULL; dqopt->info[cnt].dqi_flags = 0; dqopt->info[cnt].dqi_igrace = 0; dqopt->info[cnt].dqi_bgrace = 0; dqopt->ops[cnt] = NULL; } up(&dqopt->dqoff_sem); out: unlock_kernel(); return 0; } int vfs_quota_on(struct super_block *sb, int type, int format_id, char *path) { struct file *f = NULL; struct inode *inode; struct quota_info *dqopt = sb_dqopt(sb); struct quota_format_type *fmt = find_quota_format(format_id); int error; if (!fmt) return -ESRCH; if (is_enabled(dqopt, type)) { error = -EBUSY; goto out_fmt; } down(&dqopt->dqoff_sem); f = filp_open(path, O_RDWR, 0600); error = PTR_ERR(f); if (IS_ERR(f)) goto out_lock; dqopt->files[type] = f; error = -EIO; if (!f->f_op || !f->f_op->read || !f->f_op->write) goto out_f; inode = f->f_dentry->d_inode; error = -EACCES; if (!S_ISREG(inode->i_mode)) goto out_f; error = -EINVAL; if (!fmt->qf_ops->check_quota_file(sb, type)) goto out_f; /* We don't want quota and atime on quota files */ dquot_drop(inode); inode->i_flags |= S_NOQUOTA | S_NOATIME; dqopt->ops[type] = fmt->qf_ops; dqopt->info[type].dqi_format = fmt; if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) goto out_f; set_enable_flags(dqopt, type); add_dquot_ref(sb, type); up(&dqopt->dqoff_sem); return 0; out_f: if (f) filp_close(f, NULL); dqopt->files[type] = NULL; out_lock: up(&dqopt->dqoff_sem); out_fmt: put_quota_format(fmt); return error; } /* Generic routine for getting common part of quota structure */ static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di) { struct mem_dqblk *dm = &dquot->dq_dqb; di->dqb_bhardlimit = dm->dqb_bhardlimit; di->dqb_bsoftlimit = dm->dqb_bsoftlimit; di->dqb_curspace = dm->dqb_curspace; di->dqb_ihardlimit = dm->dqb_ihardlimit; di->dqb_isoftlimit = dm->dqb_isoftlimit; di->dqb_curinodes = dm->dqb_curinodes; di->dqb_btime = dm->dqb_btime; di->dqb_itime = dm->dqb_itime; di->dqb_valid = QIF_ALL; } int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di) { struct dquot *dquot = dqget(sb, id, type); if (!dquot) return -EINVAL; do_get_dqblk(dquot, di); dqput(dquot); return 0; } /* Generic routine for setting common part of quota structure */ static void do_set_dqblk(struct dquot *dquot, struct if_dqblk *di) { struct mem_dqblk *dm = &dquot->dq_dqb; int check_blim = 0, check_ilim = 0; if (di->dqb_valid & QIF_SPACE) { dm->dqb_curspace = di->dqb_curspace; check_blim = 1; } if (di->dqb_valid & QIF_BLIMITS) { dm->dqb_bsoftlimit = di->dqb_bsoftlimit; dm->dqb_bhardlimit = di->dqb_bhardlimit; check_blim = 1; } if (di->dqb_valid & QIF_INODES) { dm->dqb_curinodes = di->dqb_curinodes; check_ilim = 1; } if (di->dqb_valid & QIF_ILIMITS) { dm->dqb_isoftlimit = di->dqb_isoftlimit; dm->dqb_ihardlimit = di->dqb_ihardlimit; check_ilim = 1; } if (di->dqb_valid & QIF_BTIME) dm->dqb_btime = di->dqb_btime; if (di->dqb_valid & QIF_ITIME) dm->dqb_itime = di->dqb_itime; if (check_blim) { if (!dm->dqb_bsoftlimit || toqb(dm->dqb_curspace) < dm->dqb_bsoftlimit) { dm->dqb_btime = 0; dquot->dq_flags &= ~DQ_BLKS; } else if (!(di->dqb_valid & QIF_BTIME)) /* Set grace only if user hasn't provided his own... */ dm->dqb_btime = CURRENT_TIME + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace; } if (check_ilim) { if (!dm->dqb_isoftlimit || dm->dqb_curinodes < dm->dqb_isoftlimit) { dm->dqb_itime = 0; dquot->dq_flags &= ~DQ_INODES; } else if (!(di->dqb_valid & QIF_ITIME)) /* Set grace only if user hasn't provided his own... */ dm->dqb_itime = CURRENT_TIME + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; } if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit) dquot->dq_flags &= ~DQ_FAKE; else dquot->dq_flags |= DQ_FAKE; dquot->dq_flags |= DQ_MOD; } int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di) { struct dquot *dquot = dqget(sb, id, type); if (!dquot) return -EINVAL; do_set_dqblk(dquot, di); dqput(dquot); return 0; } /* Generic routine for getting common part of quota file information */ int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) { struct mem_dqinfo *mi = sb_dqopt(sb)->info + type; ii->dqi_bgrace = mi->dqi_bgrace; ii->dqi_igrace = mi->dqi_igrace; ii->dqi_flags = mi->dqi_flags & DQF_MASK; ii->dqi_valid = IIF_ALL; return 0; } /* Generic routine for setting common part of quota file information */ int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) { struct mem_dqinfo *mi = sb_dqopt(sb)->info + type; if (ii->dqi_valid & IIF_BGRACE) mi->dqi_bgrace = ii->dqi_bgrace; if (ii->dqi_valid & IIF_IGRACE) mi->dqi_igrace = ii->dqi_igrace; if (ii->dqi_valid & IIF_FLAGS) mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | (ii->dqi_flags & DQF_MASK); mark_info_dirty(mi); return 0; } struct quotactl_ops vfs_quotactl_ops = { quota_on: vfs_quota_on, quota_off: vfs_quota_off, quota_sync: vfs_quota_sync, get_info: vfs_get_dqinfo, set_info: vfs_set_dqinfo, get_dqblk: vfs_get_dqblk, set_dqblk: vfs_set_dqblk }; static ctl_table fs_dqstats_table[] = { {FS_DQ_LOOKUPS, "lookups", &dqstats.lookups, sizeof(int), 0444, NULL, &proc_dointvec}, {FS_DQ_DROPS, "drops", &dqstats.drops, sizeof(int), 0444, NULL, &proc_dointvec}, {FS_DQ_READS, "reads", &dqstats.reads, sizeof(int), 0444, NULL, &proc_dointvec}, {FS_DQ_WRITES, "writes", &dqstats.writes, sizeof(int), 0444, NULL, &proc_dointvec}, {FS_DQ_CACHE_HITS, "cache_hits", &dqstats.cache_hits, sizeof(int), 0444, NULL, &proc_dointvec}, {FS_DQ_ALLOCATED, "allocated_dquots", &dqstats.allocated_dquots, sizeof(int), 0444, NULL, &proc_dointvec}, {FS_DQ_FREE, "free_dquots", &dqstats.free_dquots, sizeof(int), 0444, NULL, &proc_dointvec}, {FS_DQ_SYNCS, "syncs", &dqstats.syncs, sizeof(int), 0444, NULL, &proc_dointvec}, {FS_DQ_WARNINGS, "warnings", &flag_print_warnings, sizeof(int), 0644, NULL, &proc_dointvec}, {}, }; static ctl_table fs_table[] = { {FS_DQSTATS, "quota", NULL, 0, 0555, fs_dqstats_table}, {}, }; static ctl_table sys_table[] = { {CTL_FS, "fs", NULL, 0, 0555, fs_table}, {}, }; static int __init dquot_init(void) { int i; register_sysctl_table(sys_table, 0); for (i = 0; i < NR_DQHASH; i++) INIT_LIST_HEAD(dquot_hash + i); printk(KERN_NOTICE "VFS: Disk quotas v%s\n", __DQUOT_VERSION__); return 0; } __initcall(dquot_init); EXPORT_SYMBOL(register_quota_format); EXPORT_SYMBOL(unregister_quota_format); EXPORT_SYMBOL(dqstats); EXPORT_SYMBOL(init_dquot_operations);