diff options
Diffstat (limited to 'fs/dquot.c')
| -rw-r--r-- | fs/dquot.c | 2005 |
1 files changed, 0 insertions, 2005 deletions
diff --git a/fs/dquot.c b/fs/dquot.c deleted file mode 100644 index 41b9dbd68b0..00000000000 --- a/fs/dquot.c +++ /dev/null @@ -1,2005 +0,0 @@ -/* - * Implementation of the diskquota system for the LINUX operating system. QUOTA - * is implemented using the BSD system call interface as the means of - * communication with the user level. This file contains the generic routines - * called by the different filesystems on allocation of an inode or block. - * These routines take care of the administration needed to have a consistent - * diskquota tracking system. The ideas of both user and group quotas are based - * on the Melbourne quota system as used on BSD derived systems. The internal - * implementation is based on one of the several variants of the LINUX - * inode-subsystem with added complexity of the diskquota system. - * - * 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/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 <linux/capability.h> -#include <linux/quotaops.h> -#include <linux/writeback.h> /* for inode_lock, oddly enough.. */ -#ifdef CONFIG_QUOTA_NETLINK_INTERFACE -#include <net/netlink.h> -#include <net/genetlink.h> -#endif - -#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_mutex is also needed). If operation is holding - * reference to dquot in other way (e.g. quotactl ops) it must be guarded by - * dqonoff_mutex. - * 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 mutex. 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_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock > - * dqio_mutex - * i_mutex on quota files is special (it's below dqio_mutex) - */ - -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 struct kmem_cache *dquot_cachep; - -int register_quota_format(struct quota_format_type *fmt) -{ - spin_lock(&dq_list_lock); - fmt->qf_next = quota_formats; - quota_formats = fmt; - spin_unlock(&dq_list_lock); - return 0; -} - -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_tail(&dquot->dq_free, &free_dquots); - 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_tail(&dquot->dq_inuse, &inuse_list); - 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) -{ - mutex_lock(&dquot->dq_lock); - mutex_unlock(&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); - - mutex_lock(&dquot->dq_lock); - mutex_lock(&dqopt->dqio_mutex); - 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: - mutex_unlock(&dqopt->dqio_mutex); - mutex_unlock(&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); - - mutex_lock(&dqopt->dqio_mutex); - 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: - mutex_unlock(&dqopt->dqio_mutex); - return ret; -} - -/* - * Release dquot - */ -int dquot_release(struct dquot *dquot) -{ - int ret = 0, ret2 = 0; - struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); - - mutex_lock(&dquot->dq_lock); - /* Check whether we are not racing with some other dqget() */ - if (atomic_read(&dquot->dq_count) > 1) - goto out_dqlock; - mutex_lock(&dqopt->dqio_mutex); - 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); - mutex_unlock(&dqopt->dqio_mutex); -out_dqlock: - mutex_unlock(&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. There can still be some users of quotas due to inodes being - * just deleted or pruned by prune_icache() (those are not attached to any - * list). We have to wait for such users. - */ -static void invalidate_dquots(struct super_block *sb, int type) -{ - struct dquot *dquot, *tmp; - -restart: - spin_lock(&dq_list_lock); - list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { - if (dquot->dq_sb != sb) - continue; - if (dquot->dq_type != type) - continue; - /* Wait for dquot users */ - if (atomic_read(&dquot->dq_count)) { - DEFINE_WAIT(wait); - - atomic_inc(&dquot->dq_count); - prepare_to_wait(&dquot->dq_wait_unused, &wait, - TASK_UNINTERRUPTIBLE); - spin_unlock(&dq_list_lock); - /* Once dqput() wakes us up, we know it's time to free - * the dquot. - * IMPORTANT: we rely on the fact that there is always - * at most one process waiting for dquot to free. - * Otherwise dq_count would be > 1 and we would never - * wake up. - */ - if (atomic_read(&dquot->dq_count) > 1) - schedule(); - finish_wait(&dquot->dq_wait_unused, &wait); - dqput(dquot); - /* At this moment dquot() need not exist (it could be - * reclaimed by prune_dqcache(). Hence we must - * restart. */ - goto restart; - } - /* - * Quota now has no users and it has been written on last - * dqput() - */ - remove_dquot_hash(dquot); - remove_free_dquot(dquot); - remove_inuse(dquot); - 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; - - mutex_lock(&dqopt->dqonoff_mutex); - 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_first_entry(dirty, 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); - mutex_unlock(&dqopt->dqonoff_mutex); - - 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, gfp_t 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; -} - -static struct shrinker dqcache_shrinker = { - .shrink = shrink_dqcache_memory, - .seeks = DEFAULT_SEEKS, -}; - -/* - * 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_mutex 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); - /* Releasing dquot during quotaoff phase? */ - if (!sb_has_quota_enabled(dquot->dq_sb, dquot->dq_type) && - atomic_read(&dquot->dq_count) == 1) - wake_up(&dquot->dq_wait_unused); - 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 */ - BUG_ON(!list_empty(&dquot->dq_free)); -#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_zalloc(dquot_cachep, GFP_NOFS); - if(!dquot) - return NODQUOT; - - mutex_init(&dquot->dq_lock); - INIT_LIST_HEAD(&dquot->dq_free); - INIT_LIST_HEAD(&dquot->dq_inuse); - INIT_HLIST_NODE(&dquot->dq_hash); - INIT_LIST_HEAD(&dquot->dq_dirty); - init_waitqueue_head(&dquot->dq_wait_unused); - 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_mutex 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 - BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ -#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_mutex mutex */ -static void add_dquot_ref(struct super_block *sb, int type) -{ - struct inode *inode, *old_inode = NULL; - - spin_lock(&inode_lock); - list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { - if (!atomic_read(&inode->i_writecount)) - continue; - if (!dqinit_needed(inode, type)) - continue; - if (inode->i_state & (I_FREEING|I_WILL_FREE)) - continue; - - __iget(inode); - spin_unlock(&inode_lock); - - iput(old_inode); - sb->dq_op->initialize(inode, type); - /* We hold a reference to 'inode' so it couldn't have been - * removed from s_inodes list while we dropped the inode_lock. - * We cannot iput the inode now as we can be holding the last - * reference and we cannot iput it under inode_lock. So we - * keep the reference and iput it later. */ - old_inode = inode; - spin_lock(&inode_lock); - } - spin_unlock(&inode_lock); - iput(old_inode); -} - -/* 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... */ -static 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); - } -} - -static void remove_dquot_ref(struct super_block *sb, int type, - struct list_head *tofree_head) -{ - struct inode *inode; - - spin_lock(&inode_lock); - list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { - if (!IS_NOQUOTA(inode)) - remove_inode_dquot_ref(inode, type, tofree_head); - } - spin_unlock(&inode_lock); -} - -/* Gather all references from inodes and drop them */ -static void drop_dquot_ref(struct super_block *sb, int type) -{ - LIST_HEAD(tofree_head); - - if (sb->dq_op) { - down_write(&sb_dqopt(sb)->dqptr_sem); - remove_dquot_ref(sb, type, &tofree_head); - up_write(&sb_dqopt(sb)->dqptr_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 warning_issued(struct dquot *dquot, const int warntype) -{ - int flag = (warntype == QUOTA_NL_BHARDWARN || - warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : - ((warntype == QUOTA_NL_IHARDWARN || - warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); - - if (!flag) - return 0; - return test_and_set_bit(flag, &dquot->dq_flags); -} - -#ifdef CONFIG_PRINT_QUOTA_WARNING -static int flag_print_warnings = 1; - -static 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; -} - -/* Print warning to user which exceeded quota */ -static void print_warning(struct dquot *dquot, const int warntype) -{ - char *msg = NULL; - struct tty_struct *tty; - - if (!need_print_warning(dquot)) - return; - - mutex_lock(&tty_mutex); - tty = get_current_tty(); - if (!tty) - goto out_lock; - tty_write_message(tty, dquot->dq_sb->s_id); - if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) - tty_write_message(tty, ": warning, "); - else - tty_write_message(tty, ": write failed, "); - tty_write_message(tty, quotatypes[dquot->dq_type]); - switch (warntype) { - case QUOTA_NL_IHARDWARN: - msg = " file limit reached.\r\n"; - break; - case QUOTA_NL_ISOFTLONGWARN: - msg = " file quota exceeded too long.\r\n"; - break; - case QUOTA_NL_ISOFTWARN: - msg = " file quota exceeded.\r\n"; - break; - case QUOTA_NL_BHARDWARN: - msg = " block limit reached.\r\n"; - break; - case QUOTA_NL_BSOFTLONGWARN: - msg = " block quota exceeded too long.\r\n"; - break; - case QUOTA_NL_BSOFTWARN: - msg = " block quota exceeded.\r\n"; - break; - } - tty_write_message(tty, msg); -out_lock: - mutex_unlock(&tty_mutex); -} -#endif - -#ifdef CONFIG_QUOTA_NETLINK_INTERFACE - -/* Netlink family structure for quota */ -static struct genl_family quota_genl_family = { - .id = GENL_ID_GENERATE, - .hdrsize = 0, - .name = "VFS_DQUOT", - .version = 1, - .maxattr = QUOTA_NL_A_MAX, -}; - -/* Send warning to userspace about user which exceeded quota */ -static void send_warning(const struct dquot *dquot, const char warntype) -{ - static atomic_t seq; - struct sk_buff *skb; - void *msg_head; - int ret; - int msg_size = 4 * nla_total_size(sizeof(u32)) + - 2 * nla_total_size(sizeof(u64)); - - /* We have to allocate using GFP_NOFS as we are called from a - * filesystem performing write and thus further recursion into - * the fs to free some data could cause deadlocks. */ - skb = genlmsg_new(msg_size, GFP_NOFS); - if (!skb) { - printk(KERN_ERR - "VFS: Not enough memory to send quota warning.\n"); - return; - } - msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq), - "a_genl_family, 0, QUOTA_NL_C_WARNING); - if (!msg_head) { - printk(KERN_ERR - "VFS: Cannot store netlink header in quota warning.\n"); - goto err_out; - } - ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, dquot->dq_type); - if (ret) - goto attr_err_out; - ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, dquot->dq_id); - if (ret) - goto attr_err_out; - ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype); - if (ret) - goto attr_err_out; - ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, - MAJOR(dquot->dq_sb->s_dev)); - if (ret) - goto attr_err_out; - ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, - MINOR(dquot->dq_sb->s_dev)); - if (ret) - goto attr_err_out; - ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current->user->uid); - if (ret) - goto attr_err_out; - genlmsg_end(skb, msg_head); - - ret = genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS); - if (ret < 0 && ret != -ESRCH) - printk(KERN_ERR - "VFS: Failed to send notification message: %d\n", ret); - return; -attr_err_out: - printk(KERN_ERR "VFS: Not enough space to compose quota message!\n"); -err_out: - kfree_skb(skb); -} -#endif - -static inline void flush_warnings(struct dquot * const *dquots, char *warntype) -{ - int i; - - for (i = 0; i < MAXQUOTAS; i++) - if (dquots[i] != NODQUOT && warntype[i] != QUOTA_NL_NOWARN && - !warning_issued(dquots[i], warntype[i])) { -#ifdef CONFIG_PRINT_QUOTA_WARNING - print_warning(dquots[i], warntype[i]); -#endif -#ifdef CONFIG_QUOTA_NETLINK_INTERFACE - send_warning(dquots[i], warntype[i]); -#endif - } -} - -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 = QUOTA_NL_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 = QUOTA_NL_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 = QUOTA_NL_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 = QUOTA_NL_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 = QUOTA_NL_NOWARN; - 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 = QUOTA_NL_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 = QUOTA_NL_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 = QUOTA_NL_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 mutex - solves deadlocks when we - * re-enter the quota code and are already holding the mutex */ - 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 mutex - solves deadlocks when we - * re-enter the quota code and are already holding the mutex */ - if (IS_NOQUOTA(inode)) { -out_add: - inode_add_bytes(inode, number); - return QUOTA_OK; - } - for (cnt = 0; cnt < MAXQUOTAS; cnt++) - warntype[cnt] = QUOTA_NL_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 mutex - solves deadlocks when we - * re-enter the quota code and are already holding the mutex */ - if (IS_NOQUOTA(inode)) - return QUOTA_OK; - for (cnt = 0; cnt < MAXQUOTAS; cnt++) - warntype[cnt] = QUOTA_NL_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(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 mutex - solves deadlocks when we - * re-enter the quota code and are already holding the mutex */ - 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 mutex - solves deadlocks when we - * re-enter the quota code and are already holding the mutex */ - 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 mutex - solves deadlocks when we - * re-enter the quota code and are already holding the mutex */ - 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] = QUOTA_NL_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); - - mutex_lock(&dqopt->dqio_mutex); - ret = dqopt->ops[type]->write_file_info(sb, type); - mutex_unlock(&dqopt->dqio_mutex); - 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]; - - /* We need to serialize quota_off() for device */ - mutex_lock(&dqopt->dqonoff_mutex); - for (cnt = 0; cnt < MAXQUOTAS; cnt++) { - toputinode[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]; - dqopt->files[cnt] = NULL; - dqopt->info[cnt].dqi_flags = 0; - dqopt->info[cnt].dqi_igrace = 0; - dqopt->info[cnt].dqi_bgrace = 0; - dqopt->ops[cnt] = NULL; - } - mutex_unlock(&dqopt->dqonoff_mutex); - /* Sync the superblock so that buffers with quota data are written to - * disk (and so userspace sees correct data afterwards). */ - if (sb->s_op->sync_fs) - sb->s_op->sync_fs(sb, 1); - sync_blockdev(sb->s_bdev); - /* Now the quota files are just ordinary files and we can set the - * inode flags back. Moreover we discard the pagecache so that - * userspace sees the writes we did bypassing the pagecache. We - * must also discard the blockdev buffers so that we see the - * changes done by userspace on the next quotaon() */ - for (cnt = 0; cnt < MAXQUOTAS; cnt++) - if (toputinode[cnt]) { - mutex_lock(&dqopt->dqonoff_mutex); - /* If quota was reenabled in the meantime, we have - * nothing to do */ - if (!sb_has_quota_enabled(sb, cnt)) { - mutex_lock_nested(&toputinode[cnt]->i_mutex, I_MUTEX_QUOTA); - toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | - S_NOATIME | S_NOQUOTA); - truncate_inode_pages(&toputinode[cnt]->i_data, 0); - mutex_unlock(&toputinode[cnt]->i_mutex); - mark_inode_dirty(toputinode[cnt]); - } - iput(toputinode[cnt]); - mutex_unlock(&dqopt->dqonoff_mutex); - } - if (sb->s_bdev) - invalidate_bdev(sb->s_bdev); - 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); - mutex_lock(&inode->i_mutex); - mutex_lock(&dqopt->dqonoff_mutex); - 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); - sb->dq_op->drop(inode); - - 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); - mutex_lock(&dqopt->dqio_mutex); - if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) { - mutex_unlock(&dqopt->dqio_mutex); - goto out_file_init; - } - mutex_unlock(&dqopt->dqio_mutex); - mutex_unlock(&inode->i_mutex); - set_enable_flags(dqopt, type); - - add_dquot_ref(sb, type); - mutex_unlock(&dqopt->dqonoff_mutex); - - return 0; - -out_file_init: - dqopt->files[type] = NULL; - iput(inode); -out_lock: - mutex_unlock(&dqopt->dqonoff_mutex); - 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); - } - mutex_unlock(&inode->i_mutex); -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.path.dentry); - if (error) - goto out_path; - /* Quota file not on the same filesystem? */ - if (nd.path.mnt->mnt_sb != sb) - error = -EXDEV; - else - error = vfs_quota_on_inode(nd.path.dentry->d_inode, type, - format_id); -out_path: - path_put(&nd.path); - return error; -} - -/* - * This function is used when filesystem needs to initialize quotas - * during mount time. - */ -int vfs_quota_on_mount(struct super_block *sb, char *qf_name, - int format_id, int type) -{ - struct dentry *dentry; - int error; - - dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name)); - if (IS_ERR(dentry)) - return PTR_ERR(dentry); - - if (!dentry->d_inode) { - error = -ENOENT; - goto out; - } - - error = security_quota_on(dentry); - if (!error) - error = vfs_quota_on_inode(dentry->d_inode, type, format_id); - -out: - dput(dentry); - 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; - - 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; - - mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); - if (!(dquot = dqget(sb, id, type))) { - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); - return -ESRCH; - } - do_get_dqblk(dquot, di); - dqput(dquot); - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); - 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; - - mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); - if (!(dquot = dqget(sb, id, type))) { - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); - return -ESRCH; - } - do_set_dqblk(dquot, di); - dqput(dquot); - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); - 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; - - mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); - if (!sb_has_quota_enabled(sb, type)) { - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); - 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); - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); - 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; - - mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); - if (!sb_has_quota_enabled(sb, type)) { - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); - 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); - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); - 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, - }, -#ifdef CONFIG_PRINT_QUOTA_WARNING - { - .ctl_name = FS_DQ_WARNINGS, - .procname = "warnings", - .data = &flag_print_warnings, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = &proc_dointvec, - }, -#endif - { .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); - - dquot_cachep = kmem_cache_create("dquot", - sizeof(struct dquot), sizeof(unsigned long) * 4, - (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| - SLAB_MEM_SPREAD|SLAB_PANIC), - NULL); - - order = 0; - dquot_hash = (struct hlist_head *)__get_free_pages(GFP_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)); - - register_shrinker(&dqcache_shrinker); - -#ifdef CONFIG_QUOTA_NETLINK_INTERFACE - if (genl_register_family("a_genl_family) != 0) - printk(KERN_ERR "VFS: Failed to create quota netlink interface.\n"); -#endif - - 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); |