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Diffstat (limited to 'fs/dquot.c')
| -rw-r--r-- | fs/dquot.c | 1850 |
1 files changed, 1850 insertions, 0 deletions
diff --git a/fs/dquot.c b/fs/dquot.c new file mode 100644 index 00000000000..11048e0b32c --- /dev/null +++ b/fs/dquot.c @@ -0,0 +1,1850 @@ +/* + * 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. + * + * Version: $Id: dquot.c,v 6.3 1996/11/17 18:35:34 mvw Exp mvw $ + * + * Author: Marco van Wieringen <mvw@planets.elm.net> + * + * Fixes: Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96 + * + * Revised list management to avoid races + * -- Bill Hawes, <whawes@star.net>, 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, <jack@suse.cz>, 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, <jack@suse.cz>, 9/2000 + * + * Added dynamic quota structure allocation + * Jan Kara <jack@suse.cz> 12/2000 + * + * Rewritten quota interface. Implemented new quota format and + * formats registering. + * Jan Kara, <jack@suse.cz>, 2001,2002 + * + * New SMP locking. + * Jan Kara, <jack@suse.cz>, 10/2002 + * + * Added journalled quota support, fix lock inversion problems + * Jan Kara, <jack@suse.cz>, 2003,2004 + * + * (C) Copyright 1994 - 1997 Marco van Wieringen + */ + +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/mount.h> +#include <linux/mm.h> +#include <linux/time.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/fcntl.h> +#include <linux/stat.h> +#include <linux/tty.h> +#include <linux/file.h> +#include <linux/slab.h> +#include <linux/sysctl.h> +#include <linux/smp_lock.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/proc_fs.h> +#include <linux/security.h> +#include <linux/kmod.h> +#include <linux/namei.h> +#include <linux/buffer_head.h> + +#include <asm/uaccess.h> + +#define __DQUOT_PARANOIA + +/* + * There are two quota SMP locks. dq_list_lock protects all lists with quotas + * and quota formats and also dqstats structure containing statistics about the + * lists. dq_data_lock protects data from dq_dqb and also mem_dqinfo structures + * and also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes. + * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly + * in inode_add_bytes() and inode_sub_bytes(). + * + * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_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 + * + * Any operation working on dquots via inode pointers must hold dqptr_sem. If + * operation is just reading pointers from inode (or not using them at all) the + * read lock is enough. If pointers are altered function must hold write lock + * (these locking rules also apply for S_NOQUOTA flag in the inode - note that + * for altering the flag i_sem is also needed). If operation is holding + * reference to dquot in other way (e.g. quotactl ops) it must be guarded by + * dqonoff_sem. + * This locking assures that: + * a) update/access to dquot pointers in inode is serialized + * b) everyone is guarded against invalidate_dquots() + * + * Each dquot has its dq_lock semaphore. Locked dquots might not be referenced + * from inodes (dquot_alloc_space() and such don't check the dq_lock). + * Currently dquot is locked only when it is being read to memory (or space for + * it is being allocated) on the first dqget() and when it is being released on + * the last dqput(). The allocation and release oparations are serialized by + * the dq_lock and by checking the use count in dquot_release(). Write + * operations on dquots don't hold dq_lock as they copy data under dq_data_lock + * spinlock to internal buffers before writing. + * + * Lock ordering (including related VFS locks) is the following: + * i_sem > dqonoff_sem > iprune_sem > journal_lock > dqptr_sem > + * > dquot->dq_lock > dqio_sem + * i_sem on quota files is special (it's below dqio_sem) + */ + +static DEFINE_SPINLOCK(dq_list_lock); +DEFINE_SPINLOCK(dq_data_lock); + +static char *quotatypes[] = INITQFNAMES; +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 kmem_cache_t *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; +} + +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); +} + +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 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 invalidate operation, 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. + */ + +static LIST_HEAD(inuse_list); +static LIST_HEAD(free_dquots); +static unsigned int dq_hash_bits, dq_hash_mask; +static struct hlist_head *dquot_hash; + +struct dqstats dqstats; + +static void dqput(struct dquot *dquot); + +static inline unsigned int +hashfn(const struct super_block *sb, unsigned int id, int 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 = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type); + hlist_add_head(&dquot->dq_hash, head); +} + +static inline void remove_dquot_hash(struct dquot *dquot) +{ + hlist_del_init(&dquot->dq_hash); +} + +static inline struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, unsigned int id, int type) +{ + 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 && dquot->dq_id == id && dquot->dq_type == type) + return dquot; + } + return NODQUOT; +} + +/* 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++; +} + +static inline void remove_free_dquot(struct dquot *dquot) +{ + if (list_empty(&dquot->dq_free)) + return; + list_del_init(&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); +} +/* + * End of list functions needing dq_list_lock + */ + +static void wait_on_dquot(struct dquot *dquot) +{ + down(&dquot->dq_lock); + up(&dquot->dq_lock); +} + +#define mark_dquot_dirty(dquot) ((dquot)->dq_sb->dq_op->mark_dirty(dquot)) + +int dquot_mark_dquot_dirty(struct dquot *dquot) +{ + 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_type].dqi_dirty_list); + spin_unlock(&dq_list_lock); + return 0; +} + +/* This function needs dq_list_lock */ +static inline int clear_dquot_dirty(struct dquot *dquot) +{ + if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) + return 0; + list_del_init(&dquot->dq_dirty); + return 1; +} + +void mark_info_dirty(struct super_block *sb, int type) +{ + set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags); +} +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; + struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); + + down(&dquot->dq_lock); + down(&dqopt->dqio_sem); + if (!test_bit(DQ_READ_B, &dquot->dq_flags)) + ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot); + if (ret < 0) + goto out_iolock; + set_bit(DQ_READ_B, &dquot->dq_flags); + /* Instantiate dquot if needed */ + if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { + ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); + /* Write the info if needed */ + if (info_dirty(&dqopt->info[dquot->dq_type])) + ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type); + if (ret < 0) + goto out_iolock; + if (ret2 < 0) { + ret = ret2; + goto out_iolock; + } + } + set_bit(DQ_ACTIVE_B, &dquot->dq_flags); +out_iolock: + up(&dqopt->dqio_sem); + up(&dquot->dq_lock); + return ret; +} + +/* + * Write dquot to disk + */ +int dquot_commit(struct dquot *dquot) +{ + int ret = 0, ret2 = 0; + struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); + + down(&dqopt->dqio_sem); + spin_lock(&dq_list_lock); + if (!clear_dquot_dirty(dquot)) { + spin_unlock(&dq_list_lock); + goto out_sem; + } + spin_unlock(&dq_list_lock); + /* Inactive dquot can be only if there was error during read/init + * => we have better not writing it */ + if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { + ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); + if (info_dirty(&dqopt->info[dquot->dq_type])) + ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type); + if (ret >= 0) + ret = ret2; + } +out_sem: + up(&dqopt->dqio_sem); + return ret; +} + +/* + * Release dquot + */ +int dquot_release(struct dquot *dquot) +{ + int ret = 0, ret2 = 0; + struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); + + down(&dquot->dq_lock); + /* Check whether we are not racing with some other dqget() */ + if (atomic_read(&dquot->dq_count) > 1) + goto out_dqlock; + down(&dqopt->dqio_sem); + if (dqopt->ops[dquot->dq_type]->release_dqblk) { + ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot); + /* Write the info */ + if (info_dirty(&dqopt->info[dquot->dq_type])) + ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type); + if (ret >= 0) + ret = ret2; + } + clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); + up(&dqopt->dqio_sem); +out_dqlock: + up(&dquot->dq_lock); + return ret; +} + +/* 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. Also because we hold dqonoff_sem there can be no quota users + * for this sb+type at all. */ +static void invalidate_dquots(struct super_block *sb, int type) +{ + struct dquot *dquot; + struct list_head *head; + + spin_lock(&dq_list_lock); + for (head = inuse_list.next; head != &inuse_list;) { + dquot = list_entry(head, struct dquot, dq_inuse); + head = head->next; + if (dquot->dq_sb != sb) + continue; + if (dquot->dq_type != type) + continue; +#ifdef __DQUOT_PARANOIA + if (atomic_read(&dquot->dq_count)) + BUG(); +#endif + /* Quota now has 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); + } + spin_unlock(&dq_list_lock); +} + +int vfs_quota_sync(struct super_block *sb, int type) +{ + struct list_head *dirty; + struct dquot *dquot; + struct quota_info *dqopt = sb_dqopt(sb); + int cnt; + + down(&dqopt->dqonoff_sem); + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (type != -1 && cnt != type) + continue; + if (!sb_has_quota_enabled(sb, cnt)) + continue; + spin_lock(&dq_list_lock); + dirty = &dqopt->info[cnt].dqi_dirty_list; + while (!list_empty(dirty)) { + dquot = list_entry(dirty->next, struct dquot, dq_dirty); + /* Dirty and inactive can be only bad dquot... */ + if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { + clear_dquot_dirty(dquot); + continue; + } + /* Now we have active dquot from which someone is + * holding reference so we can safely just increase + * use count */ + atomic_inc(&dquot->dq_count); + dqstats.lookups++; + spin_unlock(&dq_list_lock); + sb->dq_op->write_dquot(dquot); + 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_enabled(sb, cnt) + && info_dirty(&dqopt->info[cnt])) + sb->dq_op->write_info(sb, cnt); + spin_lock(&dq_list_lock); + dqstats.syncs++; + spin_unlock(&dq_list_lock); + up(&dqopt->dqonoff_sem); + + return 0; +} + +/* 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 + */ + +static int shrink_dqcache_memory(int nr, unsigned int gfp_mask) +{ + if (nr) { + spin_lock(&dq_list_lock); + prune_dqcache(nr); + spin_unlock(&dq_list_lock); + } + return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure; +} + +/* + * Put reference to dquot + * NOTE: If you change this function please check whether dqput_blocks() works right... + * MUST be called with either dqptr_sem or dqonoff_sem held + */ +static void dqput(struct dquot *dquot) +{ + if (!dquot) + return; +#ifdef __DQUOT_PARANOIA + if (!atomic_read(&dquot->dq_count)) { + printk("VFS: dqput: trying to free free dquot\n"); + printk("VFS: device %s, dquot of %s %d\n", + dquot->dq_sb->s_id, + quotatypes[dquot->dq_type], + dquot->dq_id); + BUG(); + } +#endif + + spin_lock(&dq_list_lock); + dqstats.drops++; + spin_unlock(&dq_list_lock); +we_slept: + 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); + spin_unlock(&dq_list_lock); + return; + } + /* Need to release dquot? */ + if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) { + spin_unlock(&dq_list_lock); + /* Commit dquot before releasing */ + dquot->dq_sb->dq_op->write_dquot(dquot); + goto we_slept; + } + /* Clear flag in case dquot was inactive (something bad happened) */ + clear_dquot_dirty(dquot); + if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { + spin_unlock(&dq_list_lock); + dquot->dq_sb->dq_op->release_dquot(dquot); + goto we_slept; + } + atomic_dec(&dquot->dq_count); +#ifdef __DQUOT_PARANOIA + /* sanity check */ + if (!list_empty(&dquot->dq_free)) + BUG(); +#endif + put_dquot_last(dquot); + spin_unlock(&dq_list_lock); +} + +static struct dquot *get_empty_dquot(struct super_block *sb, int type) +{ + struct dquot *dquot; + + dquot = kmem_cache_alloc(dquot_cachep, SLAB_NOFS); + if(!dquot) + return NODQUOT; + + memset((caddr_t)dquot, 0, sizeof(struct dquot)); + sema_init(&dquot->dq_lock, 1); + 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_type = type; + atomic_set(&dquot->dq_count, 1); + + return dquot; +} + +/* + * Get reference to dquot + * MUST be called with either dqptr_sem or dqonoff_sem held + */ +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; + + if (!sb_has_quota_enabled(sb, type)) + return NODQUOT; +we_slept: + spin_lock(&dq_list_lock); + if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) { + if (empty == NODQUOT) { + spin_unlock(&dq_list_lock); + if ((empty = get_empty_dquot(sb, type)) == NODQUOT) + schedule(); /* Try to wait for a moment... */ + goto we_slept; + } + dquot = empty; + dquot->dq_id = id; + /* all dquots go on the inuse_list */ + put_inuse(dquot); + /* hash it first so it can be found */ + insert_dquot_hash(dquot); + dqstats.lookups++; + spin_unlock(&dq_list_lock); + } else { + if (!atomic_read(&dquot->dq_count)) + remove_free_dquot(dquot); + atomic_inc(&dquot->dq_count); + dqstats.cache_hits++; + dqstats.lookups++; + spin_unlock(&dq_list_lock); + if (empty) + kmem_cache_free(dquot_cachep, empty); + } + /* Wait for dq_lock - after this we know that either dquot_release() is already + * finished or it will be canceled due to dq_count > 1 test */ + wait_on_dquot(dquot); + /* Read the dquot and instantiate it (everything done only if needed) */ + if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) { + dqput(dquot); + return NODQUOT; + } +#ifdef __DQUOT_PARANOIA + if (!dquot->dq_sb) /* Has somebody invalidated entry under us? */ + BUG(); +#endif + + return dquot; +} + +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; +} + +/* This routine is guarded by dqonoff_sem semaphore */ +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 dentry *dentry = dget(filp->f_dentry); + file_list_unlock(); + sb->dq_op->initialize(inode, type); + dput(dentry); + /* 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 (atomic_read(&dquot->dq_count) <= 1) + return 1; + return 0; +} + +/* Remove references to dquots from inode - add dquot to list for freeing if needed */ +/* We can't race with anybody because we hold dqptr_sem for writing... */ +int remove_inode_dquot_ref(struct inode *inode, int type, struct list_head *tofree_head) +{ + struct dquot *dquot = inode->i_dquot[type]; + + inode->i_dquot[type] = NODQUOT; + if (dquot != NODQUOT) { + if (dqput_blocks(dquot)) { +#ifdef __DQUOT_PARANOIA + if (atomic_read(&dquot->dq_count) != 1) + printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count)); +#endif + spin_lock(&dq_list_lock); + list_add(&dquot->dq_free, tofree_head); /* As dquot must have currently users it can't be on the free list... */ + spin_unlock(&dq_list_lock); + return 1; + } + else + dqput(dquot); /* We have guaranteed we won't block */ + } + return 0; +} + +/* Free list of dquots - called from inode.c */ +/* dquots are removed from inodes, 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; + /* 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_init(&dquot->dq_free); /* Remove dquot from the list so we won't have problems... */ + dqput(dquot); + } +} + +/* Gather all references from inodes and drop them */ +static void drop_dquot_ref(struct super_block *sb, int type) +{ + LIST_HEAD(tofree_head); + + /* We need to be guarded against prune_icache to reach all the + * inodes - otherwise some can be on the local list of prune_icache */ + down(&iprune_sem); + down_write(&sb_dqopt(sb)->dqptr_sem); + remove_dquot_ref(sb, type, &tofree_head); + up_write(&sb_dqopt(sb)->dqptr_sem); + up(&iprune_sem); + put_dquot_list(&tofree_head); +} + +static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number) +{ + dquot->dq_dqb.dqb_curinodes += number; +} + +static inline void dquot_incr_space(struct dquot *dquot, qsize_t number) +{ + dquot->dq_dqb.dqb_curspace += number; +} + +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; + clear_bit(DQ_INODES_B, &dquot->dq_flags); +} + +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; + clear_bit(DQ_BLKS_B, &dquot->dq_flags); +} + +static int flag_print_warnings = 1; + +static inline int need_print_warning(struct dquot *dquot) +{ + if (!flag_print_warnings) + return 0; + + switch (dquot->dq_type) { + case USRQUOTA: + return current->fsuid == dquot->dq_id; + case GRPQUOTA: + return in_group_p(dquot->dq_id); + } + 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_B : + ((warntype == IHARDWARN || warntype == ISOFTLONGWARN) ? DQ_INODES_B : 0); + + if (!need_print_warning(dquot) || (flag && test_and_set_bit(flag, &dquot->dq_flags))) + return; + + tty_write_message(current->signal->tty, dquot->dq_sb->s_id); + if (warntype == ISOFTWARN || warntype == BSOFTWARN) + tty_write_message(current->signal->tty, ": warning, "); + else + tty_write_message(current->signal->tty, ": write failed, "); + tty_write_message(current->signal->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->signal->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)); +} + +/* needs dq_data_lock */ +static int check_idq(struct dquot *dquot, ulong inodes, char *warntype) +{ + *warntype = NOWARN; + if (inodes <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags)) + 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 && get_seconds() >= 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 = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; + } + + return QUOTA_OK; +} + +/* needs dq_data_lock */ +static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype) +{ + *warntype = 0; + if (space <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags)) + 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 && get_seconds() >= 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 = get_seconds() + 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; +} + +/* + * Initialize quota pointers in inode + * Transaction must be started at entry + */ +int dquot_initialize(struct inode *inode, int type) +{ + unsigned int id = 0; + int cnt, ret = 0; + + /* First test before acquiring semaphore - solves deadlocks when we + * re-enter the quota code and are already holding the semaphore */ + if (IS_NOQUOTA(inode)) + return 0; + down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); + /* Having dqptr_sem we know NOQUOTA flags can't be altered... */ + if (IS_NOQUOTA(inode)) + goto out_err; + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (type != -1 && cnt != type) + continue; + if (inode->i_dquot[cnt] == NODQUOT) { + switch (cnt) { + case USRQUOTA: + id = inode->i_uid; + break; + case GRPQUOTA: + id = inode->i_gid; + break; + } + inode->i_dquot[cnt] = dqget(inode->i_sb, id, cnt); + } + } +out_err: + up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); + return ret; +} + +/* + * Release all quotas referenced by inode + * Transaction must be started at an entry + */ +int dquot_drop(struct inode *inode) +{ + int cnt; + + down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (inode->i_dquot[cnt] != NODQUOT) { + dqput(inode->i_dquot[cnt]); + inode->i_dquot[cnt] = NODQUOT; + } + } + up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); + return 0; +} + +/* + * Following four functions update i_blocks+i_bytes fields and + * quota information (together with appropriate checks) + * NOTE: We absolutely rely on the fact that caller dirties + * the inode (usually macros 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 warn) +{ + int cnt, ret = NO_QUOTA; + char warntype[MAXQUOTAS]; + + /* First test before acquiring semaphore - solves deadlocks when we + * re-enter the quota code and are already holding the semaphore */ + if (IS_NOQUOTA(inode)) { +out_add: + inode_add_bytes(inode, number); + return QUOTA_OK; + } + for (cnt = 0; cnt < MAXQUOTAS; cnt++) + warntype[cnt] = NOWARN; + + down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + if (IS_NOQUOTA(inode)) { /* Now we can do reliable test... */ + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + goto out_add; + } + spin_lock(&dq_data_lock); + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (inode->i_dquot[cnt] == NODQUOT) + continue; + if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt) == NO_QUOTA) + goto warn_put_all; + } + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (inode->i_dquot[cnt] == NODQUOT) + continue; + dquot_incr_space(inode->i_dquot[cnt], number); + } + inode_add_bytes(inode, number); + ret = QUOTA_OK; +warn_put_all: + spin_unlock(&dq_data_lock); + if (ret == QUOTA_OK) + /* Dirtify all the dquots - this can block when journalling */ + for (cnt = 0; cnt < MAXQUOTAS; cnt++) + if (inode->i_dquot[cnt]) + mark_dquot_dirty(inode->i_dquot[cnt]); + flush_warnings(inode->i_dquot, warntype); + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + 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; + char warntype[MAXQUOTAS]; + + /* First test before acquiring semaphore - solves deadlocks when we + * re-enter the quota code and are already holding the semaphore */ + if (IS_NOQUOTA(inode)) + return QUOTA_OK; + for (cnt = 0; cnt < MAXQUOTAS; cnt++) + warntype[cnt] = NOWARN; + down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + if (IS_NOQUOTA(inode)) { + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + return QUOTA_OK; + } + spin_lock(&dq_data_lock); + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (inode->i_dquot[cnt] == NODQUOT) + continue; + if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) == NO_QUOTA) + goto warn_put_all; + } + + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (inode->i_dquot[cnt] == NODQUOT) + continue; + dquot_incr_inodes(inode->i_dquot[cnt], number); + } + ret = QUOTA_OK; +warn_put_all: + spin_unlock(&dq_data_lock); + if (ret == QUOTA_OK) + /* Dirtify all the dquots - this can block when journalling */ + for (cnt = 0; cnt < MAXQUOTAS; cnt++) + if (inode->i_dquot[cnt]) + mark_dquot_dirty(inode->i_dquot[cnt]); + flush_warnings((struct dquot **)inode->i_dquot, warntype); + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + return ret; +} + +/* + * This operation can block, but only after everything is updated + */ +int dquot_free_space(struct inode *inode, qsize_t number) +{ + unsigned int cnt; + + /* First test before acquiring semaphore - solves deadlocks when we + * re-enter the quota code and are already holding the semaphore */ + if (IS_NOQUOTA(inode)) { +out_sub: + inode_sub_bytes(inode, number); + return QUOTA_OK; + } + down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + /* Now recheck reliably when holding dqptr_sem */ + if (IS_NOQUOTA(inode)) { + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + goto out_sub; + } + spin_lock(&dq_data_lock); + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (inode->i_dquot[cnt] == NODQUOT) + continue; + dquot_decr_space(inode->i_dquot[cnt], number); + } + inode_sub_bytes(inode, number); + spin_unlock(&dq_data_lock); + /* Dirtify all the dquots - this can block when journalling */ + for (cnt = 0; cnt < MAXQUOTAS; cnt++) + if (inode->i_dquot[cnt]) + mark_dquot_dirty(inode->i_dquot[cnt]); + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + return QUOTA_OK; +} + +/* + * This operation can block, but only after everything is updated + */ +int dquot_free_inode(const struct inode *inode, unsigned long number) +{ + unsigned int cnt; + + /* First test before acquiring semaphore - solves deadlocks when we + * re-enter the quota code and are already holding the semaphore */ + if (IS_NOQUOTA(inode)) + return QUOTA_OK; + down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + /* Now recheck reliably when holding dqptr_sem */ + if (IS_NOQUOTA(inode)) { + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + return QUOTA_OK; + } + spin_lock(&dq_data_lock); + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (inode->i_dquot[cnt] == NODQUOT) + continue; + dquot_decr_inodes(inode->i_dquot[cnt], number); + } + spin_unlock(&dq_data_lock); + /* Dirtify all the dquots - this can block when journalling */ + for (cnt = 0; cnt < MAXQUOTAS; cnt++) + if (inode->i_dquot[cnt]) + mark_dquot_dirty(inode->i_dquot[cnt]); + up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); + return QUOTA_OK; +} + +/* + * Transfer the number of inode and blocks from one diskquota to an other. + * + * This operation can block, but only after everything is updated + * A transaction must be started when entering this function. + */ +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]; + + /* First test before acquiring semaphore - solves deadlocks when we + * re-enter the quota code and are already holding the semaphore */ + if (IS_NOQUOTA(inode)) + return QUOTA_OK; + /* Clear the arrays */ + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + transfer_to[cnt] = transfer_from[cnt] = NODQUOT; + warntype[cnt] = NOWARN; + } + down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); + /* Now recheck reliably when holding dqptr_sem */ + if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ + up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); + return QUOTA_OK; + } + /* First build the transfer_to list - here we can block on + * reading/instantiating of dquots. We know that the transaction for + * us was already started so we don't violate lock ranking here */ + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + 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; + } + } + spin_lock(&dq_data_lock); + space = inode_get_bytes(inode); + /* Build the transfer_from list and check the limits */ + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (transfer_to[cnt] == NODQUOT) + continue; + transfer_from[cnt] = inode->i_dquot[cnt]; + 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 turned off quota-type. + */ + if (transfer_to[cnt] == NODQUOT) + continue; + + /* Due to IO error we might not have transfer_from[] structure */ + if (transfer_from[cnt]) { + 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); + + inode->i_dquot[cnt] = transfer_to[cnt]; + } + ret = QUOTA_OK; +warn_put_all: + spin_unlock(&dq_data_lock); + /* Dirtify all the dquots - this can block when journalling */ + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (transfer_from[cnt]) + mark_dquot_dirty(transfer_from[cnt]); + if (transfer_to[cnt]) + mark_dquot_dirty(transfer_to[cnt]); + } + flush_warnings(transfer_to, warntype); + + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (ret == QUOTA_OK && transfer_from[cnt] != NODQUOT) + dqput(transfer_from[cnt]); + if (ret == NO_QUOTA && transfer_to[cnt] != NODQUOT) + dqput(transfer_to[cnt]); + } + up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); + return ret; +} + +/* + * Write info of quota file to disk + */ +int dquot_commit_info(struct super_block *sb, int type) +{ + int ret; + struct quota_info *dqopt = sb_dqopt(sb); + + down(&dqopt->dqio_sem); + ret = dqopt->ops[type]->write_file_info(sb, type); + up(&dqopt->dqio_sem); + return ret; +} + +/* + * Definitions of diskquota operations. + */ +struct dquot_operations dquot_operations = { + .initialize = dquot_initialize, + .drop = dquot_drop, + .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 = dquot_commit, + .acquire_dquot = dquot_acquire, + .release_dquot = dquot_release, + .mark_dirty = dquot_mark_dquot_dirty, + .write_info = dquot_commit_info +}; + +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; + } +} + +/* + * 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); + struct inode *toputinode[MAXQUOTAS]; + struct vfsmount *toputmnt[MAXQUOTAS]; + + /* We need to serialize quota_off() for device */ + down(&dqopt->dqonoff_sem); + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + toputinode[cnt] = NULL; + toputmnt[cnt] = NULL; + if (type != -1 && cnt != type) + continue; + if (!sb_has_quota_enabled(sb, cnt)) + continue; + reset_enable_flags(dqopt, cnt); + + /* 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); + + toputinode[cnt] = dqopt->files[cnt]; + toputmnt[cnt] = dqopt->mnt[cnt]; + dqopt->files[cnt] = NULL; + dqopt->mnt[cnt] = 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->dqonoff_sem); + /* Sync the superblock so that buffers with quota data are written to + * disk (and so userspace sees correct data afterwards). + * The reference to vfsmnt we are still holding protects us from + * umount (we don't have it only when quotas are turned on/off for + * journal replay but in that case we are guarded by the fs anyway). */ + 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 (toputinode[cnt]) { + down(&dqopt->dqonoff_sem); + /* If quota was reenabled in the meantime, we have + * nothing to do */ + if (!sb_has_quota_enabled(sb, cnt)) { + down(&toputinode[cnt]->i_sem); + toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | + S_NOATIME | S_NOQUOTA); + truncate_inode_pages(&toputinode[cnt]->i_data, 0); + up(&toputinode[cnt]->i_sem); + mark_inode_dirty(toputinode[cnt]); + iput(toputinode[cnt]); + } + up(&dqopt->dqonoff_sem); + /* We don't hold the reference when we turned on quotas + * just for the journal replay... */ + if (toputmnt[cnt]) + mntput(toputmnt[cnt]); + } + if (sb->s_bdev) + invalidate_bdev(sb->s_bdev, 0); + return 0; +} + +/* + * Turn quotas on on a device + */ + +/* Helper function when we already have the inode */ +static int vfs_quota_on_inode(struct inode *inode, int type, int format_id) +{ + struct quota_format_type *fmt = find_quota_format(format_id); + struct super_block *sb = inode->i_sb; + struct quota_info *dqopt = sb_dqopt(sb); + int error; + int oldflags = -1; + + if (!fmt) + return -ESRCH; + if (!S_ISREG(inode->i_mode)) { + error = -EACCES; + goto out_fmt; + } + if (IS_RDONLY(inode)) { + error = -EROFS; + goto out_fmt; + } + if (!sb->s_op->quota_write || !sb->s_op->quota_read) { + error = -EINVAL; + goto out_fmt; + } + + /* As we bypass the pagecache we must now flush the inode so that + * we see all the changes from userspace... */ + write_inode_now(inode, 1); + /* And now flush the block cache so that kernel sees the changes */ + invalidate_bdev(sb->s_bdev, 0); + down(&inode->i_sem); + down(&dqopt->dqonoff_sem); + if (sb_has_quota_enabled(sb, type)) { + error = -EBUSY; + goto out_lock; + } + /* 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. */ + down_write(&dqopt->dqptr_sem); + oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | S_NOQUOTA); + inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE; + up_write(&dqopt->dqptr_sem); + + error = -EIO; + dqopt->files[type] = igrab(inode); + if (!dqopt->files[type]) + goto out_lock; + error = -EINVAL; + if (!fmt->qf_ops->check_quota_file(sb, type)) + goto out_file_init; + + dqopt->ops[type] = fmt->qf_ops; + dqopt->info[type].dqi_format = fmt; + INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); + down(&dqopt->dqio_sem); + if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) { + up(&dqopt->dqio_sem); + goto out_file_init; + } + up(&dqopt->dqio_sem); + up(&inode->i_sem); + set_enable_flags(dqopt, type); + + add_dquot_ref(sb, type); + up(&dqopt->dqonoff_sem); + + return 0; + +out_file_init: + dqopt->files[type] = NULL; + iput(inode); +out_lock: + up(&dqopt->dqonoff_sem); + if (oldflags != -1) { + down_write(&dqopt->dqptr_sem); + /* Set the flags back (in the case of accidental quotaon() + * on a wrong file we don't want to mess up the flags) */ + inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE); + inode->i_flags |= oldflags; + up_write(&dqopt->dqptr_sem); + } + up(&inode->i_sem); +out_fmt: + put_quota_format(fmt); + + return error; +} + +/* Actual function called from quotactl() */ +int vfs_quota_on(struct super_block *sb, int type, int format_id, char *path) +{ + struct nameidata nd; + int error; + + error = path_lookup(path, LOOKUP_FOLLOW, &nd); + if (error < 0) + return error; + error = security_quota_on(nd.dentry); + if (error) + goto out_path; + /* Quota file not on the same filesystem? */ + if (nd.mnt->mnt_sb != sb) + error = -EXDEV; + else { + error = vfs_quota_on_inode(nd.dentry->d_inode, type, format_id); + if (!error) + sb_dqopt(sb)->mnt[type] = mntget(nd.mnt); + } +out_path: + path_release(&nd); + return error; +} + +/* + * This function is used when filesystem needs to initialize quotas + * during mount time. + */ +int vfs_quota_on_mount(int type, int format_id, struct dentry *dentry) +{ + int error; + + error = security_quota_on(dentry); + if (error) + return error; + return vfs_quota_on_inode(dentry->d_inode, type, format_id); +} + +/* 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; + + spin_lock(&dq_data_lock); + 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; + spin_unlock(&dq_data_lock); +} + +int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di) +{ + struct dquot *dquot; + + down(&sb_dqopt(sb)->dqonoff_sem); + if (!(dquot = dqget(sb, id, type))) { + up(&sb_dqopt(sb)->dqonoff_sem); + return -ESRCH; + } + do_get_dqblk(dquot, di); + dqput(dquot); + up(&sb_dqopt(sb)->dqonoff_sem); + 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; + + spin_lock(&dq_data_lock); + 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; + clear_bit(DQ_BLKS_B, &dquot->dq_flags); + } + else if (!(di->dqb_valid & QIF_BTIME)) /* Set grace only if user hasn't provided his own... */ + dm->dqb_btime = get_seconds() + 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; + clear_bit(DQ_INODES_B, &dquot->dq_flags); + } + else if (!(di->dqb_valid & QIF_ITIME)) /* Set grace only if user hasn't provided his own... */ + dm->dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].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(&dq_data_lock); + mark_dquot_dirty(dquot); +} + +int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di) +{ + struct dquot *dquot; + + down(&sb_dqopt(sb)->dqonoff_sem); + if (!(dquot = dqget(sb, id, type))) { + up(&sb_dqopt(sb)->dqonoff_sem); + return -ESRCH; + } + do_set_dqblk(dquot, di); + dqput(dquot); + up(&sb_dqopt(sb)->dqonoff_sem); + 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; + + down(&sb_dqopt(sb)->dqonoff_sem); + if (!sb_has_quota_enabled(sb, type)) { + up(&sb_dqopt(sb)->dqonoff_sem); + return -ESRCH; + } + mi = sb_dqopt(sb)->info + type; + spin_lock(&dq_data_lock); + 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; + spin_unlock(&dq_data_lock); + up(&sb_dqopt(sb)->dqonoff_sem); + 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; + + down(&sb_dqopt(sb)->dqonoff_sem); + if (!sb_has_quota_enabled(sb, type)) { + up(&sb_dqopt(sb)->dqonoff_sem); + return -ESRCH; + } + mi = sb_dqopt(sb)->info + type; + spin_lock(&dq_data_lock); + 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); + spin_unlock(&dq_data_lock); + mark_info_dirty(sb, type); + /* Force write to disk */ + sb->dq_op->write_info(sb, type); + up(&sb_dqopt(sb)->dqonoff_sem); + 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[] = { + { + .ctl_name = FS_DQ_LOOKUPS, + .procname = "lookups", + .data = &dqstats.lookups, + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = FS_DQ_DROPS, + .procname = "drops", + .data = &dqstats.drops, + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = FS_DQ_READS, + .procname = "reads", + .data = &dqstats.reads, + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = FS_DQ_WRITES, + .procname = "writes", + .data = &dqstats.writes, + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = FS_DQ_CACHE_HITS, + .procname = "cache_hits", + .data = &dqstats.cache_hits, + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = FS_DQ_ALLOCATED, + .procname = "allocated_dquots", + .data = &dqstats.allocated_dquots, + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = FS_DQ_FREE, + .procname = "free_dquots", + .data = &dqstats.free_dquots, + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = FS_DQ_SYNCS, + .procname = "syncs", + .data = &dqstats.syncs, + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = FS_DQ_WARNINGS, + .procname = "warnings", + .data = &flag_print_warnings, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, + { .ctl_name = 0 }, +}; + +static ctl_table fs_table[] = { + { + .ctl_name = FS_DQSTATS, + .procname = "quota", + .mode = 0555, + .child = fs_dqstats_table, + }, + { .ctl_name = 0 }, +}; + +static ctl_table sys_table[] = { + { + .ctl_name = CTL_FS, + .procname = "fs", + .mode = 0555, + .child = fs_table, + }, + { .ctl_name = 0 }, +}; + +static int __init dquot_init(void) +{ + int i; + unsigned long nr_hash, order; + + printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); + + register_sysctl_table(sys_table, 0); + + dquot_cachep = kmem_cache_create("dquot", + sizeof(struct dquot), sizeof(unsigned long) * 4, + SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_PANIC, + NULL, NULL); + + order = 0; + dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); + if (!dquot_hash) + panic("Cannot create dquot hash table"); + + /* Find power-of-two hlist_heads which can fit into allocation */ + nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); + dq_hash_bits = 0; + do { + dq_hash_bits++; + } while (nr_hash >> dq_hash_bits); + dq_hash_bits--; + + 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); + + printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n", + nr_hash, order, (PAGE_SIZE << order)); + + set_shrinker(DEFAULT_SEEKS, shrink_dqcache_memory); + + return 0; +} +module_init(dquot_init); + +EXPORT_SYMBOL(register_quota_format); +EXPORT_SYMBOL(unregister_quota_format); +EXPORT_SYMBOL(dqstats); +EXPORT_SYMBOL(dq_data_lock); +EXPORT_SYMBOL(vfs_quota_on); +EXPORT_SYMBOL(vfs_quota_on_mount); +EXPORT_SYMBOL(vfs_quota_off); +EXPORT_SYMBOL(vfs_quota_sync); +EXPORT_SYMBOL(vfs_get_dqinfo); +EXPORT_SYMBOL(vfs_set_dqinfo); +EXPORT_SYMBOL(vfs_get_dqblk); +EXPORT_SYMBOL(vfs_set_dqblk); +EXPORT_SYMBOL(dquot_commit); +EXPORT_SYMBOL(dquot_commit_info); +EXPORT_SYMBOL(dquot_acquire); +EXPORT_SYMBOL(dquot_release); +EXPORT_SYMBOL(dquot_mark_dquot_dirty); +EXPORT_SYMBOL(dquot_initialize); +EXPORT_SYMBOL(dquot_drop); +EXPORT_SYMBOL(dquot_alloc_space); +EXPORT_SYMBOL(dquot_alloc_inode); +EXPORT_SYMBOL(dquot_free_space); +EXPORT_SYMBOL(dquot_free_inode); +EXPORT_SYMBOL(dquot_transfer); |