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linux/fs/dquot.c
Jan Kara c525460e27 Don't send quota messages repeatedly when hardlimit reached 
We should send quota message to netlink only once when hardlimit is
reached.  Otherwise user could easily make the system busy by trying to
exceed the hardlimit (and also the messages could be anoying if you cannot
stop writing just now).

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-23 12:54:36 -08:00

2000 lines
56 KiB
C
Raw Blame History

/*
* 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 = &quota_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;
restart:
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);
sb->dq_op->initialize(inode, type);
iput(inode);
/* As we may have blocked we had better restart... */
goto restart;
}
spin_unlock(&inode_lock);
}
/* 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),
&quota_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.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);
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(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(&quota_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);
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