Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/fs/dquot.c b/fs/dquot.c
new file mode 100644
index 0000000..11048e0
--- /dev/null
+++ b/fs/dquot.c
@@ -0,0 +1,1850 @@
+/*
+ * Implementation of the diskquota system for the LINUX operating system. QUOTA
+ * is implemented using the BSD system call interface as the means of
+ * communication with the user level. This file contains the generic routines
+ * called by the different filesystems on allocation of an inode or block.
+ * These routines take care of the administration needed to have a consistent
+ * diskquota tracking system. The ideas of both user and group quotas are based
+ * on the Melbourne quota system as used on BSD derived systems. The internal
+ * implementation is based on one of the several variants of the LINUX
+ * inode-subsystem with added complexity of the diskquota system.
+ *
+ * Version: $Id: dquot.c,v 6.3 1996/11/17 18:35:34 mvw Exp mvw $
+ *
+ * Author: Marco van Wieringen <mvw@planets.elm.net>
+ *
+ * Fixes: Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
+ *
+ * Revised list management to avoid races
+ * -- Bill Hawes, <whawes@star.net>, 9/98
+ *
+ * Fixed races in dquot_transfer(), dqget() and dquot_alloc_...().
+ * As the consequence the locking was moved from dquot_decr_...(),
+ * dquot_incr_...() to calling functions.
+ * invalidate_dquots() now writes modified dquots.
+ * Serialized quota_off() and quota_on() for mount point.
+ * Fixed a few bugs in grow_dquots().
+ * Fixed deadlock in write_dquot() - we no longer account quotas on
+ * quota files
+ * remove_dquot_ref() moved to inode.c - it now traverses through inodes
+ * add_dquot_ref() restarts after blocking
+ * Added check for bogus uid and fixed check for group in quotactl.
+ * Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99
+ *
+ * Used struct list_head instead of own list struct
+ * Invalidation of referenced dquots is no longer possible
+ * Improved free_dquots list management
+ * Quota and i_blocks are now updated in one place to avoid races
+ * Warnings are now delayed so we won't block in critical section
+ * Write updated not to require dquot lock
+ * Jan Kara, <jack@suse.cz>, 9/2000
+ *
+ * Added dynamic quota structure allocation
+ * Jan Kara <jack@suse.cz> 12/2000
+ *
+ * Rewritten quota interface. Implemented new quota format and
+ * formats registering.
+ * Jan Kara, <jack@suse.cz>, 2001,2002
+ *
+ * New SMP locking.
+ * Jan Kara, <jack@suse.cz>, 10/2002
+ *
+ * Added journalled quota support, fix lock inversion problems
+ * Jan Kara, <jack@suse.cz>, 2003,2004
+ *
+ * (C) Copyright 1994 - 1997 Marco van Wieringen
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/mm.h>
+#include <linux/time.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/tty.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/sysctl.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/security.h>
+#include <linux/kmod.h>
+#include <linux/namei.h>
+#include <linux/buffer_head.h>
+
+#include <asm/uaccess.h>
+
+#define __DQUOT_PARANOIA
+
+/*
+ * There are two quota SMP locks. dq_list_lock protects all lists with quotas
+ * and quota formats and also dqstats structure containing statistics about the
+ * lists. dq_data_lock protects data from dq_dqb and also mem_dqinfo structures
+ * and also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
+ * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
+ * in inode_add_bytes() and inode_sub_bytes().
+ *
+ * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock
+ *
+ * Note that some things (eg. sb pointer, type, id) doesn't change during
+ * the life of the dquot structure and so needn't to be protected by a lock
+ *
+ * Any operation working on dquots via inode pointers must hold dqptr_sem. If
+ * operation is just reading pointers from inode (or not using them at all) the
+ * read lock is enough. If pointers are altered function must hold write lock
+ * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
+ * for altering the flag i_sem is also needed). If operation is holding
+ * reference to dquot in other way (e.g. quotactl ops) it must be guarded by
+ * dqonoff_sem.
+ * This locking assures that:
+ * a) update/access to dquot pointers in inode is serialized
+ * b) everyone is guarded against invalidate_dquots()
+ *
+ * Each dquot has its dq_lock semaphore. Locked dquots might not be referenced
+ * from inodes (dquot_alloc_space() and such don't check the dq_lock).
+ * Currently dquot is locked only when it is being read to memory (or space for
+ * it is being allocated) on the first dqget() and when it is being released on
+ * the last dqput(). The allocation and release oparations are serialized by
+ * the dq_lock and by checking the use count in dquot_release(). Write
+ * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
+ * spinlock to internal buffers before writing.
+ *
+ * Lock ordering (including related VFS locks) is the following:
+ * i_sem > dqonoff_sem > iprune_sem > journal_lock > dqptr_sem >
+ * > dquot->dq_lock > dqio_sem
+ * i_sem on quota files is special (it's below dqio_sem)
+ */
+
+static DEFINE_SPINLOCK(dq_list_lock);
+DEFINE_SPINLOCK(dq_data_lock);
+
+static char *quotatypes[] = INITQFNAMES;
+static struct quota_format_type *quota_formats; /* List of registered formats */
+static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
+
+/* SLAB cache for dquot structures */
+static kmem_cache_t *dquot_cachep;
+
+int register_quota_format(struct quota_format_type *fmt)
+{
+ spin_lock(&dq_list_lock);
+ fmt->qf_next = quota_formats;
+ quota_formats = fmt;
+ spin_unlock(&dq_list_lock);
+ return 0;
+}
+
+void unregister_quota_format(struct quota_format_type *fmt)
+{
+ struct quota_format_type **actqf;
+
+ spin_lock(&dq_list_lock);
+ for (actqf = "a_formats; *actqf && *actqf != fmt; actqf = &(*actqf)->qf_next);
+ if (*actqf)
+ *actqf = (*actqf)->qf_next;
+ spin_unlock(&dq_list_lock);
+}
+
+static struct quota_format_type *find_quota_format(int id)
+{
+ struct quota_format_type *actqf;
+
+ spin_lock(&dq_list_lock);
+ for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
+ if (!actqf || !try_module_get(actqf->qf_owner)) {
+ int qm;
+
+ spin_unlock(&dq_list_lock);
+
+ for (qm = 0; module_names[qm].qm_fmt_id && module_names[qm].qm_fmt_id != id; qm++);
+ if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name))
+ return NULL;
+
+ spin_lock(&dq_list_lock);
+ for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
+ if (actqf && !try_module_get(actqf->qf_owner))
+ actqf = NULL;
+ }
+ spin_unlock(&dq_list_lock);
+ return actqf;
+}
+
+static void put_quota_format(struct quota_format_type *fmt)
+{
+ module_put(fmt->qf_owner);
+}
+
+/*
+ * Dquot List Management:
+ * The quota code uses three lists for dquot management: the inuse_list,
+ * free_dquots, and dquot_hash[] array. A single dquot structure may be
+ * on all three lists, depending on its current state.
+ *
+ * All dquots are placed to the end of inuse_list when first created, and this
+ * list is used for invalidate operation, which must look at every dquot.
+ *
+ * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
+ * and this list is searched whenever we need an available dquot. Dquots are
+ * removed from the list as soon as they are used again, and
+ * dqstats.free_dquots gives the number of dquots on the list. When
+ * dquot is invalidated it's completely released from memory.
+ *
+ * Dquots with a specific identity (device, type and id) are placed on
+ * one of the dquot_hash[] hash chains. The provides an efficient search
+ * mechanism to locate a specific dquot.
+ */
+
+static LIST_HEAD(inuse_list);
+static LIST_HEAD(free_dquots);
+static unsigned int dq_hash_bits, dq_hash_mask;
+static struct hlist_head *dquot_hash;
+
+struct dqstats dqstats;
+
+static void dqput(struct dquot *dquot);
+
+static inline unsigned int
+hashfn(const struct super_block *sb, unsigned int id, int type)
+{
+ unsigned long tmp;
+
+ tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
+ return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
+}
+
+/*
+ * Following list functions expect dq_list_lock to be held
+ */
+static inline void insert_dquot_hash(struct dquot *dquot)
+{
+ struct hlist_head *head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
+ hlist_add_head(&dquot->dq_hash, head);
+}
+
+static inline void remove_dquot_hash(struct dquot *dquot)
+{
+ hlist_del_init(&dquot->dq_hash);
+}
+
+static inline struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, unsigned int id, int type)
+{
+ struct hlist_node *node;
+ struct dquot *dquot;
+
+ hlist_for_each (node, dquot_hash+hashent) {
+ dquot = hlist_entry(node, struct dquot, dq_hash);
+ if (dquot->dq_sb == sb && dquot->dq_id == id && dquot->dq_type == type)
+ return dquot;
+ }
+ return NODQUOT;
+}
+
+/* Add a dquot to the tail of the free list */
+static inline void put_dquot_last(struct dquot *dquot)
+{
+ list_add(&dquot->dq_free, free_dquots.prev);
+ dqstats.free_dquots++;
+}
+
+static inline void remove_free_dquot(struct dquot *dquot)
+{
+ if (list_empty(&dquot->dq_free))
+ return;
+ list_del_init(&dquot->dq_free);
+ dqstats.free_dquots--;
+}
+
+static inline void put_inuse(struct dquot *dquot)
+{
+ /* We add to the back of inuse list so we don't have to restart
+ * when traversing this list and we block */
+ list_add(&dquot->dq_inuse, inuse_list.prev);
+ dqstats.allocated_dquots++;
+}
+
+static inline void remove_inuse(struct dquot *dquot)
+{
+ dqstats.allocated_dquots--;
+ list_del(&dquot->dq_inuse);
+}
+/*
+ * End of list functions needing dq_list_lock
+ */
+
+static void wait_on_dquot(struct dquot *dquot)
+{
+ down(&dquot->dq_lock);
+ up(&dquot->dq_lock);
+}
+
+#define mark_dquot_dirty(dquot) ((dquot)->dq_sb->dq_op->mark_dirty(dquot))
+
+int dquot_mark_dquot_dirty(struct dquot *dquot)
+{
+ spin_lock(&dq_list_lock);
+ if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags))
+ list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
+ info[dquot->dq_type].dqi_dirty_list);
+ spin_unlock(&dq_list_lock);
+ return 0;
+}
+
+/* This function needs dq_list_lock */
+static inline int clear_dquot_dirty(struct dquot *dquot)
+{
+ if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
+ return 0;
+ list_del_init(&dquot->dq_dirty);
+ return 1;
+}
+
+void mark_info_dirty(struct super_block *sb, int type)
+{
+ set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
+}
+EXPORT_SYMBOL(mark_info_dirty);
+
+/*
+ * Read dquot from disk and alloc space for it
+ */
+
+int dquot_acquire(struct dquot *dquot)
+{
+ int ret = 0, ret2 = 0;
+ struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+ down(&dquot->dq_lock);
+ down(&dqopt->dqio_sem);
+ if (!test_bit(DQ_READ_B, &dquot->dq_flags))
+ ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
+ if (ret < 0)
+ goto out_iolock;
+ set_bit(DQ_READ_B, &dquot->dq_flags);
+ /* Instantiate dquot if needed */
+ if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
+ ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
+ /* Write the info if needed */
+ if (info_dirty(&dqopt->info[dquot->dq_type]))
+ ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
+ if (ret < 0)
+ goto out_iolock;
+ if (ret2 < 0) {
+ ret = ret2;
+ goto out_iolock;
+ }
+ }
+ set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
+out_iolock:
+ up(&dqopt->dqio_sem);
+ up(&dquot->dq_lock);
+ return ret;
+}
+
+/*
+ * Write dquot to disk
+ */
+int dquot_commit(struct dquot *dquot)
+{
+ int ret = 0, ret2 = 0;
+ struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+ down(&dqopt->dqio_sem);
+ spin_lock(&dq_list_lock);
+ if (!clear_dquot_dirty(dquot)) {
+ spin_unlock(&dq_list_lock);
+ goto out_sem;
+ }
+ spin_unlock(&dq_list_lock);
+ /* Inactive dquot can be only if there was error during read/init
+ * => we have better not writing it */
+ if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
+ ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
+ if (info_dirty(&dqopt->info[dquot->dq_type]))
+ ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
+ if (ret >= 0)
+ ret = ret2;
+ }
+out_sem:
+ up(&dqopt->dqio_sem);
+ return ret;
+}
+
+/*
+ * Release dquot
+ */
+int dquot_release(struct dquot *dquot)
+{
+ int ret = 0, ret2 = 0;
+ struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+ down(&dquot->dq_lock);
+ /* Check whether we are not racing with some other dqget() */
+ if (atomic_read(&dquot->dq_count) > 1)
+ goto out_dqlock;
+ down(&dqopt->dqio_sem);
+ if (dqopt->ops[dquot->dq_type]->release_dqblk) {
+ ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
+ /* Write the info */
+ if (info_dirty(&dqopt->info[dquot->dq_type]))
+ ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type);
+ if (ret >= 0)
+ ret = ret2;
+ }
+ clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
+ up(&dqopt->dqio_sem);
+out_dqlock:
+ up(&dquot->dq_lock);
+ return ret;
+}
+
+/* Invalidate all dquots on the list. Note that this function is called after
+ * quota is disabled and pointers from inodes removed so there cannot be new
+ * quota users. Also because we hold dqonoff_sem there can be no quota users
+ * for this sb+type at all. */
+static void invalidate_dquots(struct super_block *sb, int type)
+{
+ struct dquot *dquot;
+ struct list_head *head;
+
+ spin_lock(&dq_list_lock);
+ for (head = inuse_list.next; head != &inuse_list;) {
+ dquot = list_entry(head, struct dquot, dq_inuse);
+ head = head->next;
+ if (dquot->dq_sb != sb)
+ continue;
+ if (dquot->dq_type != type)
+ continue;
+#ifdef __DQUOT_PARANOIA
+ if (atomic_read(&dquot->dq_count))
+ BUG();
+#endif
+ /* Quota now has no users and it has been written on last dqput() */
+ remove_dquot_hash(dquot);
+ remove_free_dquot(dquot);
+ remove_inuse(dquot);
+ kmem_cache_free(dquot_cachep, dquot);
+ }
+ spin_unlock(&dq_list_lock);
+}
+
+int vfs_quota_sync(struct super_block *sb, int type)
+{
+ struct list_head *dirty;
+ struct dquot *dquot;
+ struct quota_info *dqopt = sb_dqopt(sb);
+ int cnt;
+
+ down(&dqopt->dqonoff_sem);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (type != -1 && cnt != type)
+ continue;
+ if (!sb_has_quota_enabled(sb, cnt))
+ continue;
+ spin_lock(&dq_list_lock);
+ dirty = &dqopt->info[cnt].dqi_dirty_list;
+ while (!list_empty(dirty)) {
+ dquot = list_entry(dirty->next, struct dquot, dq_dirty);
+ /* Dirty and inactive can be only bad dquot... */
+ if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
+ clear_dquot_dirty(dquot);
+ continue;
+ }
+ /* Now we have active dquot from which someone is
+ * holding reference so we can safely just increase
+ * use count */
+ atomic_inc(&dquot->dq_count);
+ dqstats.lookups++;
+ spin_unlock(&dq_list_lock);
+ sb->dq_op->write_dquot(dquot);
+ dqput(dquot);
+ spin_lock(&dq_list_lock);
+ }
+ spin_unlock(&dq_list_lock);
+ }
+
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ if ((cnt == type || type == -1) && sb_has_quota_enabled(sb, cnt)
+ && info_dirty(&dqopt->info[cnt]))
+ sb->dq_op->write_info(sb, cnt);
+ spin_lock(&dq_list_lock);
+ dqstats.syncs++;
+ spin_unlock(&dq_list_lock);
+ up(&dqopt->dqonoff_sem);
+
+ return 0;
+}
+
+/* Free unused dquots from cache */
+static void prune_dqcache(int count)
+{
+ struct list_head *head;
+ struct dquot *dquot;
+
+ head = free_dquots.prev;
+ while (head != &free_dquots && count) {
+ dquot = list_entry(head, struct dquot, dq_free);
+ remove_dquot_hash(dquot);
+ remove_free_dquot(dquot);
+ remove_inuse(dquot);
+ kmem_cache_free(dquot_cachep, dquot);
+ count--;
+ head = free_dquots.prev;
+ }
+}
+
+/*
+ * This is called from kswapd when we think we need some
+ * more memory
+ */
+
+static int shrink_dqcache_memory(int nr, unsigned int gfp_mask)
+{
+ if (nr) {
+ spin_lock(&dq_list_lock);
+ prune_dqcache(nr);
+ spin_unlock(&dq_list_lock);
+ }
+ return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
+}
+
+/*
+ * Put reference to dquot
+ * NOTE: If you change this function please check whether dqput_blocks() works right...
+ * MUST be called with either dqptr_sem or dqonoff_sem held
+ */
+static void dqput(struct dquot *dquot)
+{
+ if (!dquot)
+ return;
+#ifdef __DQUOT_PARANOIA
+ if (!atomic_read(&dquot->dq_count)) {
+ printk("VFS: dqput: trying to free free dquot\n");
+ printk("VFS: device %s, dquot of %s %d\n",
+ dquot->dq_sb->s_id,
+ quotatypes[dquot->dq_type],
+ dquot->dq_id);
+ BUG();
+ }
+#endif
+
+ spin_lock(&dq_list_lock);
+ dqstats.drops++;
+ spin_unlock(&dq_list_lock);
+we_slept:
+ spin_lock(&dq_list_lock);
+ if (atomic_read(&dquot->dq_count) > 1) {
+ /* We have more than one user... nothing to do */
+ atomic_dec(&dquot->dq_count);
+ spin_unlock(&dq_list_lock);
+ return;
+ }
+ /* Need to release dquot? */
+ if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
+ spin_unlock(&dq_list_lock);
+ /* Commit dquot before releasing */
+ dquot->dq_sb->dq_op->write_dquot(dquot);
+ goto we_slept;
+ }
+ /* Clear flag in case dquot was inactive (something bad happened) */
+ clear_dquot_dirty(dquot);
+ if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
+ spin_unlock(&dq_list_lock);
+ dquot->dq_sb->dq_op->release_dquot(dquot);
+ goto we_slept;
+ }
+ atomic_dec(&dquot->dq_count);
+#ifdef __DQUOT_PARANOIA
+ /* sanity check */
+ if (!list_empty(&dquot->dq_free))
+ BUG();
+#endif
+ put_dquot_last(dquot);
+ spin_unlock(&dq_list_lock);
+}
+
+static struct dquot *get_empty_dquot(struct super_block *sb, int type)
+{
+ struct dquot *dquot;
+
+ dquot = kmem_cache_alloc(dquot_cachep, SLAB_NOFS);
+ if(!dquot)
+ return NODQUOT;
+
+ memset((caddr_t)dquot, 0, sizeof(struct dquot));
+ sema_init(&dquot->dq_lock, 1);
+ INIT_LIST_HEAD(&dquot->dq_free);
+ INIT_LIST_HEAD(&dquot->dq_inuse);
+ INIT_HLIST_NODE(&dquot->dq_hash);
+ INIT_LIST_HEAD(&dquot->dq_dirty);
+ dquot->dq_sb = sb;
+ dquot->dq_type = type;
+ atomic_set(&dquot->dq_count, 1);
+
+ return dquot;
+}
+
+/*
+ * Get reference to dquot
+ * MUST be called with either dqptr_sem or dqonoff_sem held
+ */
+static struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
+{
+ unsigned int hashent = hashfn(sb, id, type);
+ struct dquot *dquot, *empty = NODQUOT;
+
+ if (!sb_has_quota_enabled(sb, type))
+ return NODQUOT;
+we_slept:
+ spin_lock(&dq_list_lock);
+ if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) {
+ if (empty == NODQUOT) {
+ spin_unlock(&dq_list_lock);
+ if ((empty = get_empty_dquot(sb, type)) == NODQUOT)
+ schedule(); /* Try to wait for a moment... */
+ goto we_slept;
+ }
+ dquot = empty;
+ dquot->dq_id = id;
+ /* all dquots go on the inuse_list */
+ put_inuse(dquot);
+ /* hash it first so it can be found */
+ insert_dquot_hash(dquot);
+ dqstats.lookups++;
+ spin_unlock(&dq_list_lock);
+ } else {
+ if (!atomic_read(&dquot->dq_count))
+ remove_free_dquot(dquot);
+ atomic_inc(&dquot->dq_count);
+ dqstats.cache_hits++;
+ dqstats.lookups++;
+ spin_unlock(&dq_list_lock);
+ if (empty)
+ kmem_cache_free(dquot_cachep, empty);
+ }
+ /* Wait for dq_lock - after this we know that either dquot_release() is already
+ * finished or it will be canceled due to dq_count > 1 test */
+ wait_on_dquot(dquot);
+ /* Read the dquot and instantiate it (everything done only if needed) */
+ if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
+ dqput(dquot);
+ return NODQUOT;
+ }
+#ifdef __DQUOT_PARANOIA
+ if (!dquot->dq_sb) /* Has somebody invalidated entry under us? */
+ BUG();
+#endif
+
+ return dquot;
+}
+
+static int dqinit_needed(struct inode *inode, int type)
+{
+ int cnt;
+
+ if (IS_NOQUOTA(inode))
+ return 0;
+ if (type != -1)
+ return inode->i_dquot[type] == NODQUOT;
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ if (inode->i_dquot[cnt] == NODQUOT)
+ return 1;
+ return 0;
+}
+
+/* This routine is guarded by dqonoff_sem semaphore */
+static void add_dquot_ref(struct super_block *sb, int type)
+{
+ struct list_head *p;
+
+restart:
+ file_list_lock();
+ list_for_each(p, &sb->s_files) {
+ struct file *filp = list_entry(p, struct file, f_list);
+ struct inode *inode = filp->f_dentry->d_inode;
+ if (filp->f_mode & FMODE_WRITE && dqinit_needed(inode, type)) {
+ struct dentry *dentry = dget(filp->f_dentry);
+ file_list_unlock();
+ sb->dq_op->initialize(inode, type);
+ dput(dentry);
+ /* As we may have blocked we had better restart... */
+ goto restart;
+ }
+ }
+ file_list_unlock();
+}
+
+/* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */
+static inline int dqput_blocks(struct dquot *dquot)
+{
+ if (atomic_read(&dquot->dq_count) <= 1)
+ return 1;
+ return 0;
+}
+
+/* Remove references to dquots from inode - add dquot to list for freeing if needed */
+/* We can't race with anybody because we hold dqptr_sem for writing... */
+int remove_inode_dquot_ref(struct inode *inode, int type, struct list_head *tofree_head)
+{
+ struct dquot *dquot = inode->i_dquot[type];
+
+ inode->i_dquot[type] = NODQUOT;
+ if (dquot != NODQUOT) {
+ if (dqput_blocks(dquot)) {
+#ifdef __DQUOT_PARANOIA
+ if (atomic_read(&dquot->dq_count) != 1)
+ printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
+#endif
+ spin_lock(&dq_list_lock);
+ list_add(&dquot->dq_free, tofree_head); /* As dquot must have currently users it can't be on the free list... */
+ spin_unlock(&dq_list_lock);
+ return 1;
+ }
+ else
+ dqput(dquot); /* We have guaranteed we won't block */
+ }
+ return 0;
+}
+
+/* Free list of dquots - called from inode.c */
+/* dquots are removed from inodes, no new references can be got so we are the only ones holding reference */
+static void put_dquot_list(struct list_head *tofree_head)
+{
+ struct list_head *act_head;
+ struct dquot *dquot;
+
+ act_head = tofree_head->next;
+ /* So now we have dquots on the list... Just free them */
+ while (act_head != tofree_head) {
+ dquot = list_entry(act_head, struct dquot, dq_free);
+ act_head = act_head->next;
+ list_del_init(&dquot->dq_free); /* Remove dquot from the list so we won't have problems... */
+ dqput(dquot);
+ }
+}
+
+/* Gather all references from inodes and drop them */
+static void drop_dquot_ref(struct super_block *sb, int type)
+{
+ LIST_HEAD(tofree_head);
+
+ /* We need to be guarded against prune_icache to reach all the
+ * inodes - otherwise some can be on the local list of prune_icache */
+ down(&iprune_sem);
+ down_write(&sb_dqopt(sb)->dqptr_sem);
+ remove_dquot_ref(sb, type, &tofree_head);
+ up_write(&sb_dqopt(sb)->dqptr_sem);
+ up(&iprune_sem);
+ put_dquot_list(&tofree_head);
+}
+
+static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number)
+{
+ dquot->dq_dqb.dqb_curinodes += number;
+}
+
+static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
+{
+ dquot->dq_dqb.dqb_curspace += number;
+}
+
+static inline void dquot_decr_inodes(struct dquot *dquot, unsigned long number)
+{
+ if (dquot->dq_dqb.dqb_curinodes > number)
+ dquot->dq_dqb.dqb_curinodes -= number;
+ else
+ dquot->dq_dqb.dqb_curinodes = 0;
+ if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
+ dquot->dq_dqb.dqb_itime = (time_t) 0;
+ clear_bit(DQ_INODES_B, &dquot->dq_flags);
+}
+
+static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
+{
+ if (dquot->dq_dqb.dqb_curspace > number)
+ dquot->dq_dqb.dqb_curspace -= number;
+ else
+ dquot->dq_dqb.dqb_curspace = 0;
+ if (toqb(dquot->dq_dqb.dqb_curspace) <= dquot->dq_dqb.dqb_bsoftlimit)
+ dquot->dq_dqb.dqb_btime = (time_t) 0;
+ clear_bit(DQ_BLKS_B, &dquot->dq_flags);
+}
+
+static int flag_print_warnings = 1;
+
+static inline int need_print_warning(struct dquot *dquot)
+{
+ if (!flag_print_warnings)
+ return 0;
+
+ switch (dquot->dq_type) {
+ case USRQUOTA:
+ return current->fsuid == dquot->dq_id;
+ case GRPQUOTA:
+ return in_group_p(dquot->dq_id);
+ }
+ return 0;
+}
+
+/* Values of warnings */
+#define NOWARN 0
+#define IHARDWARN 1
+#define ISOFTLONGWARN 2
+#define ISOFTWARN 3
+#define BHARDWARN 4
+#define BSOFTLONGWARN 5
+#define BSOFTWARN 6
+
+/* Print warning to user which exceeded quota */
+static void print_warning(struct dquot *dquot, const char warntype)
+{
+ char *msg = NULL;
+ int flag = (warntype == BHARDWARN || warntype == BSOFTLONGWARN) ? DQ_BLKS_B :
+ ((warntype == IHARDWARN || warntype == ISOFTLONGWARN) ? DQ_INODES_B : 0);
+
+ if (!need_print_warning(dquot) || (flag && test_and_set_bit(flag, &dquot->dq_flags)))
+ return;
+
+ tty_write_message(current->signal->tty, dquot->dq_sb->s_id);
+ if (warntype == ISOFTWARN || warntype == BSOFTWARN)
+ tty_write_message(current->signal->tty, ": warning, ");
+ else
+ tty_write_message(current->signal->tty, ": write failed, ");
+ tty_write_message(current->signal->tty, quotatypes[dquot->dq_type]);
+ switch (warntype) {
+ case IHARDWARN:
+ msg = " file limit reached.\r\n";
+ break;
+ case ISOFTLONGWARN:
+ msg = " file quota exceeded too long.\r\n";
+ break;
+ case ISOFTWARN:
+ msg = " file quota exceeded.\r\n";
+ break;
+ case BHARDWARN:
+ msg = " block limit reached.\r\n";
+ break;
+ case BSOFTLONGWARN:
+ msg = " block quota exceeded too long.\r\n";
+ break;
+ case BSOFTWARN:
+ msg = " block quota exceeded.\r\n";
+ break;
+ }
+ tty_write_message(current->signal->tty, msg);
+}
+
+static inline void flush_warnings(struct dquot **dquots, char *warntype)
+{
+ int i;
+
+ for (i = 0; i < MAXQUOTAS; i++)
+ if (dquots[i] != NODQUOT && warntype[i] != NOWARN)
+ print_warning(dquots[i], warntype[i]);
+}
+
+static inline char ignore_hardlimit(struct dquot *dquot)
+{
+ struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
+
+ return capable(CAP_SYS_RESOURCE) &&
+ (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || !(info->dqi_flags & V1_DQF_RSQUASH));
+}
+
+/* needs dq_data_lock */
+static int check_idq(struct dquot *dquot, ulong inodes, char *warntype)
+{
+ *warntype = NOWARN;
+ if (inodes <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
+ return QUOTA_OK;
+
+ if (dquot->dq_dqb.dqb_ihardlimit &&
+ (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit &&
+ !ignore_hardlimit(dquot)) {
+ *warntype = IHARDWARN;
+ return NO_QUOTA;
+ }
+
+ if (dquot->dq_dqb.dqb_isoftlimit &&
+ (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
+ dquot->dq_dqb.dqb_itime && get_seconds() >= dquot->dq_dqb.dqb_itime &&
+ !ignore_hardlimit(dquot)) {
+ *warntype = ISOFTLONGWARN;
+ return NO_QUOTA;
+ }
+
+ if (dquot->dq_dqb.dqb_isoftlimit &&
+ (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
+ dquot->dq_dqb.dqb_itime == 0) {
+ *warntype = ISOFTWARN;
+ dquot->dq_dqb.dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
+ }
+
+ return QUOTA_OK;
+}
+
+/* needs dq_data_lock */
+static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
+{
+ *warntype = 0;
+ if (space <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
+ return QUOTA_OK;
+
+ if (dquot->dq_dqb.dqb_bhardlimit &&
+ toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bhardlimit &&
+ !ignore_hardlimit(dquot)) {
+ if (!prealloc)
+ *warntype = BHARDWARN;
+ return NO_QUOTA;
+ }
+
+ if (dquot->dq_dqb.dqb_bsoftlimit &&
+ toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
+ dquot->dq_dqb.dqb_btime && get_seconds() >= dquot->dq_dqb.dqb_btime &&
+ !ignore_hardlimit(dquot)) {
+ if (!prealloc)
+ *warntype = BSOFTLONGWARN;
+ return NO_QUOTA;
+ }
+
+ if (dquot->dq_dqb.dqb_bsoftlimit &&
+ toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
+ dquot->dq_dqb.dqb_btime == 0) {
+ if (!prealloc) {
+ *warntype = BSOFTWARN;
+ dquot->dq_dqb.dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
+ }
+ else
+ /*
+ * We don't allow preallocation to exceed softlimit so exceeding will
+ * be always printed
+ */
+ return NO_QUOTA;
+ }
+
+ return QUOTA_OK;
+}
+
+/*
+ * Initialize quota pointers in inode
+ * Transaction must be started at entry
+ */
+int dquot_initialize(struct inode *inode, int type)
+{
+ unsigned int id = 0;
+ int cnt, ret = 0;
+
+ /* First test before acquiring semaphore - solves deadlocks when we
+ * re-enter the quota code and are already holding the semaphore */
+ if (IS_NOQUOTA(inode))
+ return 0;
+ down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ /* Having dqptr_sem we know NOQUOTA flags can't be altered... */
+ if (IS_NOQUOTA(inode))
+ goto out_err;
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (type != -1 && cnt != type)
+ continue;
+ if (inode->i_dquot[cnt] == NODQUOT) {
+ switch (cnt) {
+ case USRQUOTA:
+ id = inode->i_uid;
+ break;
+ case GRPQUOTA:
+ id = inode->i_gid;
+ break;
+ }
+ inode->i_dquot[cnt] = dqget(inode->i_sb, id, cnt);
+ }
+ }
+out_err:
+ up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ return ret;
+}
+
+/*
+ * Release all quotas referenced by inode
+ * Transaction must be started at an entry
+ */
+int dquot_drop(struct inode *inode)
+{
+ int cnt;
+
+ down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (inode->i_dquot[cnt] != NODQUOT) {
+ dqput(inode->i_dquot[cnt]);
+ inode->i_dquot[cnt] = NODQUOT;
+ }
+ }
+ up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ return 0;
+}
+
+/*
+ * Following four functions update i_blocks+i_bytes fields and
+ * quota information (together with appropriate checks)
+ * NOTE: We absolutely rely on the fact that caller dirties
+ * the inode (usually macros in quotaops.h care about this) and
+ * holds a handle for the current transaction so that dquot write and
+ * inode write go into the same transaction.
+ */
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
+{
+ int cnt, ret = NO_QUOTA;
+ char warntype[MAXQUOTAS];
+
+ /* First test before acquiring semaphore - solves deadlocks when we
+ * re-enter the quota code and are already holding the semaphore */
+ if (IS_NOQUOTA(inode)) {
+out_add:
+ inode_add_bytes(inode, number);
+ return QUOTA_OK;
+ }
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ warntype[cnt] = NOWARN;
+
+ down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ if (IS_NOQUOTA(inode)) { /* Now we can do reliable test... */
+ up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ goto out_add;
+ }
+ spin_lock(&dq_data_lock);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (inode->i_dquot[cnt] == NODQUOT)
+ continue;
+ if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt) == NO_QUOTA)
+ goto warn_put_all;
+ }
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (inode->i_dquot[cnt] == NODQUOT)
+ continue;
+ dquot_incr_space(inode->i_dquot[cnt], number);
+ }
+ inode_add_bytes(inode, number);
+ ret = QUOTA_OK;
+warn_put_all:
+ spin_unlock(&dq_data_lock);
+ if (ret == QUOTA_OK)
+ /* Dirtify all the dquots - this can block when journalling */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ if (inode->i_dquot[cnt])
+ mark_dquot_dirty(inode->i_dquot[cnt]);
+ flush_warnings(inode->i_dquot, warntype);
+ up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ return ret;
+}
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+int dquot_alloc_inode(const struct inode *inode, unsigned long number)
+{
+ int cnt, ret = NO_QUOTA;
+ char warntype[MAXQUOTAS];
+
+ /* First test before acquiring semaphore - solves deadlocks when we
+ * re-enter the quota code and are already holding the semaphore */
+ if (IS_NOQUOTA(inode))
+ return QUOTA_OK;
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ warntype[cnt] = NOWARN;
+ down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ if (IS_NOQUOTA(inode)) {
+ up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ return QUOTA_OK;
+ }
+ spin_lock(&dq_data_lock);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (inode->i_dquot[cnt] == NODQUOT)
+ continue;
+ if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) == NO_QUOTA)
+ goto warn_put_all;
+ }
+
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (inode->i_dquot[cnt] == NODQUOT)
+ continue;
+ dquot_incr_inodes(inode->i_dquot[cnt], number);
+ }
+ ret = QUOTA_OK;
+warn_put_all:
+ spin_unlock(&dq_data_lock);
+ if (ret == QUOTA_OK)
+ /* Dirtify all the dquots - this can block when journalling */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ if (inode->i_dquot[cnt])
+ mark_dquot_dirty(inode->i_dquot[cnt]);
+ flush_warnings((struct dquot **)inode->i_dquot, warntype);
+ up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ return ret;
+}
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+int dquot_free_space(struct inode *inode, qsize_t number)
+{
+ unsigned int cnt;
+
+ /* First test before acquiring semaphore - solves deadlocks when we
+ * re-enter the quota code and are already holding the semaphore */
+ if (IS_NOQUOTA(inode)) {
+out_sub:
+ inode_sub_bytes(inode, number);
+ return QUOTA_OK;
+ }
+ down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ /* Now recheck reliably when holding dqptr_sem */
+ if (IS_NOQUOTA(inode)) {
+ up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ goto out_sub;
+ }
+ spin_lock(&dq_data_lock);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (inode->i_dquot[cnt] == NODQUOT)
+ continue;
+ dquot_decr_space(inode->i_dquot[cnt], number);
+ }
+ inode_sub_bytes(inode, number);
+ spin_unlock(&dq_data_lock);
+ /* Dirtify all the dquots - this can block when journalling */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ if (inode->i_dquot[cnt])
+ mark_dquot_dirty(inode->i_dquot[cnt]);
+ up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ return QUOTA_OK;
+}
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+int dquot_free_inode(const struct inode *inode, unsigned long number)
+{
+ unsigned int cnt;
+
+ /* First test before acquiring semaphore - solves deadlocks when we
+ * re-enter the quota code and are already holding the semaphore */
+ if (IS_NOQUOTA(inode))
+ return QUOTA_OK;
+ down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ /* Now recheck reliably when holding dqptr_sem */
+ if (IS_NOQUOTA(inode)) {
+ up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ return QUOTA_OK;
+ }
+ spin_lock(&dq_data_lock);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (inode->i_dquot[cnt] == NODQUOT)
+ continue;
+ dquot_decr_inodes(inode->i_dquot[cnt], number);
+ }
+ spin_unlock(&dq_data_lock);
+ /* Dirtify all the dquots - this can block when journalling */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ if (inode->i_dquot[cnt])
+ mark_dquot_dirty(inode->i_dquot[cnt]);
+ up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ return QUOTA_OK;
+}
+
+/*
+ * Transfer the number of inode and blocks from one diskquota to an other.
+ *
+ * This operation can block, but only after everything is updated
+ * A transaction must be started when entering this function.
+ */
+int dquot_transfer(struct inode *inode, struct iattr *iattr)
+{
+ qsize_t space;
+ struct dquot *transfer_from[MAXQUOTAS];
+ struct dquot *transfer_to[MAXQUOTAS];
+ int cnt, ret = NO_QUOTA, chuid = (iattr->ia_valid & ATTR_UID) && inode->i_uid != iattr->ia_uid,
+ chgid = (iattr->ia_valid & ATTR_GID) && inode->i_gid != iattr->ia_gid;
+ char warntype[MAXQUOTAS];
+
+ /* First test before acquiring semaphore - solves deadlocks when we
+ * re-enter the quota code and are already holding the semaphore */
+ if (IS_NOQUOTA(inode))
+ return QUOTA_OK;
+ /* Clear the arrays */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ transfer_to[cnt] = transfer_from[cnt] = NODQUOT;
+ warntype[cnt] = NOWARN;
+ }
+ down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ /* Now recheck reliably when holding dqptr_sem */
+ if (IS_NOQUOTA(inode)) { /* File without quota accounting? */
+ up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ return QUOTA_OK;
+ }
+ /* First build the transfer_to list - here we can block on
+ * reading/instantiating of dquots. We know that the transaction for
+ * us was already started so we don't violate lock ranking here */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ switch (cnt) {
+ case USRQUOTA:
+ if (!chuid)
+ continue;
+ transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_uid, cnt);
+ break;
+ case GRPQUOTA:
+ if (!chgid)
+ continue;
+ transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_gid, cnt);
+ break;
+ }
+ }
+ spin_lock(&dq_data_lock);
+ space = inode_get_bytes(inode);
+ /* Build the transfer_from list and check the limits */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (transfer_to[cnt] == NODQUOT)
+ continue;
+ transfer_from[cnt] = inode->i_dquot[cnt];
+ if (check_idq(transfer_to[cnt], 1, warntype+cnt) == NO_QUOTA ||
+ check_bdq(transfer_to[cnt], space, 0, warntype+cnt) == NO_QUOTA)
+ goto warn_put_all;
+ }
+
+ /*
+ * Finally perform the needed transfer from transfer_from to transfer_to
+ */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ /*
+ * Skip changes for same uid or gid or for turned off quota-type.
+ */
+ if (transfer_to[cnt] == NODQUOT)
+ continue;
+
+ /* Due to IO error we might not have transfer_from[] structure */
+ if (transfer_from[cnt]) {
+ dquot_decr_inodes(transfer_from[cnt], 1);
+ dquot_decr_space(transfer_from[cnt], space);
+ }
+
+ dquot_incr_inodes(transfer_to[cnt], 1);
+ dquot_incr_space(transfer_to[cnt], space);
+
+ inode->i_dquot[cnt] = transfer_to[cnt];
+ }
+ ret = QUOTA_OK;
+warn_put_all:
+ spin_unlock(&dq_data_lock);
+ /* Dirtify all the dquots - this can block when journalling */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (transfer_from[cnt])
+ mark_dquot_dirty(transfer_from[cnt]);
+ if (transfer_to[cnt])
+ mark_dquot_dirty(transfer_to[cnt]);
+ }
+ flush_warnings(transfer_to, warntype);
+
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (ret == QUOTA_OK && transfer_from[cnt] != NODQUOT)
+ dqput(transfer_from[cnt]);
+ if (ret == NO_QUOTA && transfer_to[cnt] != NODQUOT)
+ dqput(transfer_to[cnt]);
+ }
+ up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+ return ret;
+}
+
+/*
+ * Write info of quota file to disk
+ */
+int dquot_commit_info(struct super_block *sb, int type)
+{
+ int ret;
+ struct quota_info *dqopt = sb_dqopt(sb);
+
+ down(&dqopt->dqio_sem);
+ ret = dqopt->ops[type]->write_file_info(sb, type);
+ up(&dqopt->dqio_sem);
+ return ret;
+}
+
+/*
+ * Definitions of diskquota operations.
+ */
+struct dquot_operations dquot_operations = {
+ .initialize = dquot_initialize,
+ .drop = dquot_drop,
+ .alloc_space = dquot_alloc_space,
+ .alloc_inode = dquot_alloc_inode,
+ .free_space = dquot_free_space,
+ .free_inode = dquot_free_inode,
+ .transfer = dquot_transfer,
+ .write_dquot = dquot_commit,
+ .acquire_dquot = dquot_acquire,
+ .release_dquot = dquot_release,
+ .mark_dirty = dquot_mark_dquot_dirty,
+ .write_info = dquot_commit_info
+};
+
+static inline void set_enable_flags(struct quota_info *dqopt, int type)
+{
+ switch (type) {
+ case USRQUOTA:
+ dqopt->flags |= DQUOT_USR_ENABLED;
+ break;
+ case GRPQUOTA:
+ dqopt->flags |= DQUOT_GRP_ENABLED;
+ break;
+ }
+}
+
+static inline void reset_enable_flags(struct quota_info *dqopt, int type)
+{
+ switch (type) {
+ case USRQUOTA:
+ dqopt->flags &= ~DQUOT_USR_ENABLED;
+ break;
+ case GRPQUOTA:
+ dqopt->flags &= ~DQUOT_GRP_ENABLED;
+ break;
+ }
+}
+
+/*
+ * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
+ */
+int vfs_quota_off(struct super_block *sb, int type)
+{
+ int cnt;
+ struct quota_info *dqopt = sb_dqopt(sb);
+ struct inode *toputinode[MAXQUOTAS];
+ struct vfsmount *toputmnt[MAXQUOTAS];
+
+ /* We need to serialize quota_off() for device */
+ down(&dqopt->dqonoff_sem);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ toputinode[cnt] = NULL;
+ toputmnt[cnt] = NULL;
+ if (type != -1 && cnt != type)
+ continue;
+ if (!sb_has_quota_enabled(sb, cnt))
+ continue;
+ reset_enable_flags(dqopt, cnt);
+
+ /* Note: these are blocking operations */
+ drop_dquot_ref(sb, cnt);
+ invalidate_dquots(sb, cnt);
+ /*
+ * Now all dquots should be invalidated, all writes done so we should be only
+ * users of the info. No locks needed.
+ */
+ if (info_dirty(&dqopt->info[cnt]))
+ sb->dq_op->write_info(sb, cnt);
+ if (dqopt->ops[cnt]->free_file_info)
+ dqopt->ops[cnt]->free_file_info(sb, cnt);
+ put_quota_format(dqopt->info[cnt].dqi_format);
+
+ toputinode[cnt] = dqopt->files[cnt];
+ toputmnt[cnt] = dqopt->mnt[cnt];
+ dqopt->files[cnt] = NULL;
+ dqopt->mnt[cnt] = NULL;
+ dqopt->info[cnt].dqi_flags = 0;
+ dqopt->info[cnt].dqi_igrace = 0;
+ dqopt->info[cnt].dqi_bgrace = 0;
+ dqopt->ops[cnt] = NULL;
+ }
+ up(&dqopt->dqonoff_sem);
+ /* Sync the superblock so that buffers with quota data are written to
+ * disk (and so userspace sees correct data afterwards).
+ * The reference to vfsmnt we are still holding protects us from
+ * umount (we don't have it only when quotas are turned on/off for
+ * journal replay but in that case we are guarded by the fs anyway). */
+ if (sb->s_op->sync_fs)
+ sb->s_op->sync_fs(sb, 1);
+ sync_blockdev(sb->s_bdev);
+ /* Now the quota files are just ordinary files and we can set the
+ * inode flags back. Moreover we discard the pagecache so that
+ * userspace sees the writes we did bypassing the pagecache. We
+ * must also discard the blockdev buffers so that we see the
+ * changes done by userspace on the next quotaon() */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ if (toputinode[cnt]) {
+ down(&dqopt->dqonoff_sem);
+ /* If quota was reenabled in the meantime, we have
+ * nothing to do */
+ if (!sb_has_quota_enabled(sb, cnt)) {
+ down(&toputinode[cnt]->i_sem);
+ toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
+ S_NOATIME | S_NOQUOTA);
+ truncate_inode_pages(&toputinode[cnt]->i_data, 0);
+ up(&toputinode[cnt]->i_sem);
+ mark_inode_dirty(toputinode[cnt]);
+ iput(toputinode[cnt]);
+ }
+ up(&dqopt->dqonoff_sem);
+ /* We don't hold the reference when we turned on quotas
+ * just for the journal replay... */
+ if (toputmnt[cnt])
+ mntput(toputmnt[cnt]);
+ }
+ if (sb->s_bdev)
+ invalidate_bdev(sb->s_bdev, 0);
+ return 0;
+}
+
+/*
+ * Turn quotas on on a device
+ */
+
+/* Helper function when we already have the inode */
+static int vfs_quota_on_inode(struct inode *inode, int type, int format_id)
+{
+ struct quota_format_type *fmt = find_quota_format(format_id);
+ struct super_block *sb = inode->i_sb;
+ struct quota_info *dqopt = sb_dqopt(sb);
+ int error;
+ int oldflags = -1;
+
+ if (!fmt)
+ return -ESRCH;
+ if (!S_ISREG(inode->i_mode)) {
+ error = -EACCES;
+ goto out_fmt;
+ }
+ if (IS_RDONLY(inode)) {
+ error = -EROFS;
+ goto out_fmt;
+ }
+ if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
+ error = -EINVAL;
+ goto out_fmt;
+ }
+
+ /* As we bypass the pagecache we must now flush the inode so that
+ * we see all the changes from userspace... */
+ write_inode_now(inode, 1);
+ /* And now flush the block cache so that kernel sees the changes */
+ invalidate_bdev(sb->s_bdev, 0);
+ down(&inode->i_sem);
+ down(&dqopt->dqonoff_sem);
+ if (sb_has_quota_enabled(sb, type)) {
+ error = -EBUSY;
+ goto out_lock;
+ }
+ /* We don't want quota and atime on quota files (deadlocks possible)
+ * Also nobody should write to the file - we use special IO operations
+ * which ignore the immutable bit. */
+ down_write(&dqopt->dqptr_sem);
+ oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | S_NOQUOTA);
+ inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
+ up_write(&dqopt->dqptr_sem);
+
+ error = -EIO;
+ dqopt->files[type] = igrab(inode);
+ if (!dqopt->files[type])
+ goto out_lock;
+ error = -EINVAL;
+ if (!fmt->qf_ops->check_quota_file(sb, type))
+ goto out_file_init;
+
+ dqopt->ops[type] = fmt->qf_ops;
+ dqopt->info[type].dqi_format = fmt;
+ INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
+ down(&dqopt->dqio_sem);
+ if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) {
+ up(&dqopt->dqio_sem);
+ goto out_file_init;
+ }
+ up(&dqopt->dqio_sem);
+ up(&inode->i_sem);
+ set_enable_flags(dqopt, type);
+
+ add_dquot_ref(sb, type);
+ up(&dqopt->dqonoff_sem);
+
+ return 0;
+
+out_file_init:
+ dqopt->files[type] = NULL;
+ iput(inode);
+out_lock:
+ up(&dqopt->dqonoff_sem);
+ if (oldflags != -1) {
+ down_write(&dqopt->dqptr_sem);
+ /* Set the flags back (in the case of accidental quotaon()
+ * on a wrong file we don't want to mess up the flags) */
+ inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
+ inode->i_flags |= oldflags;
+ up_write(&dqopt->dqptr_sem);
+ }
+ up(&inode->i_sem);
+out_fmt:
+ put_quota_format(fmt);
+
+ return error;
+}
+
+/* Actual function called from quotactl() */
+int vfs_quota_on(struct super_block *sb, int type, int format_id, char *path)
+{
+ struct nameidata nd;
+ int error;
+
+ error = path_lookup(path, LOOKUP_FOLLOW, &nd);
+ if (error < 0)
+ return error;
+ error = security_quota_on(nd.dentry);
+ if (error)
+ goto out_path;
+ /* Quota file not on the same filesystem? */
+ if (nd.mnt->mnt_sb != sb)
+ error = -EXDEV;
+ else {
+ error = vfs_quota_on_inode(nd.dentry->d_inode, type, format_id);
+ if (!error)
+ sb_dqopt(sb)->mnt[type] = mntget(nd.mnt);
+ }
+out_path:
+ path_release(&nd);
+ return error;
+}
+
+/*
+ * This function is used when filesystem needs to initialize quotas
+ * during mount time.
+ */
+int vfs_quota_on_mount(int type, int format_id, struct dentry *dentry)
+{
+ int error;
+
+ error = security_quota_on(dentry);
+ if (error)
+ return error;
+ return vfs_quota_on_inode(dentry->d_inode, type, format_id);
+}
+
+/* Generic routine for getting common part of quota structure */
+static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
+{
+ struct mem_dqblk *dm = &dquot->dq_dqb;
+
+ spin_lock(&dq_data_lock);
+ di->dqb_bhardlimit = dm->dqb_bhardlimit;
+ di->dqb_bsoftlimit = dm->dqb_bsoftlimit;
+ di->dqb_curspace = dm->dqb_curspace;
+ di->dqb_ihardlimit = dm->dqb_ihardlimit;
+ di->dqb_isoftlimit = dm->dqb_isoftlimit;
+ di->dqb_curinodes = dm->dqb_curinodes;
+ di->dqb_btime = dm->dqb_btime;
+ di->dqb_itime = dm->dqb_itime;
+ di->dqb_valid = QIF_ALL;
+ spin_unlock(&dq_data_lock);
+}
+
+int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
+{
+ struct dquot *dquot;
+
+ down(&sb_dqopt(sb)->dqonoff_sem);
+ if (!(dquot = dqget(sb, id, type))) {
+ up(&sb_dqopt(sb)->dqonoff_sem);
+ return -ESRCH;
+ }
+ do_get_dqblk(dquot, di);
+ dqput(dquot);
+ up(&sb_dqopt(sb)->dqonoff_sem);
+ return 0;
+}
+
+/* Generic routine for setting common part of quota structure */
+static void do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
+{
+ struct mem_dqblk *dm = &dquot->dq_dqb;
+ int check_blim = 0, check_ilim = 0;
+
+ spin_lock(&dq_data_lock);
+ if (di->dqb_valid & QIF_SPACE) {
+ dm->dqb_curspace = di->dqb_curspace;
+ check_blim = 1;
+ }
+ if (di->dqb_valid & QIF_BLIMITS) {
+ dm->dqb_bsoftlimit = di->dqb_bsoftlimit;
+ dm->dqb_bhardlimit = di->dqb_bhardlimit;
+ check_blim = 1;
+ }
+ if (di->dqb_valid & QIF_INODES) {
+ dm->dqb_curinodes = di->dqb_curinodes;
+ check_ilim = 1;
+ }
+ if (di->dqb_valid & QIF_ILIMITS) {
+ dm->dqb_isoftlimit = di->dqb_isoftlimit;
+ dm->dqb_ihardlimit = di->dqb_ihardlimit;
+ check_ilim = 1;
+ }
+ if (di->dqb_valid & QIF_BTIME)
+ dm->dqb_btime = di->dqb_btime;
+ if (di->dqb_valid & QIF_ITIME)
+ dm->dqb_itime = di->dqb_itime;
+
+ if (check_blim) {
+ if (!dm->dqb_bsoftlimit || toqb(dm->dqb_curspace) < dm->dqb_bsoftlimit) {
+ dm->dqb_btime = 0;
+ clear_bit(DQ_BLKS_B, &dquot->dq_flags);
+ }
+ else if (!(di->dqb_valid & QIF_BTIME)) /* Set grace only if user hasn't provided his own... */
+ dm->dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
+ }
+ if (check_ilim) {
+ if (!dm->dqb_isoftlimit || dm->dqb_curinodes < dm->dqb_isoftlimit) {
+ dm->dqb_itime = 0;
+ clear_bit(DQ_INODES_B, &dquot->dq_flags);
+ }
+ else if (!(di->dqb_valid & QIF_ITIME)) /* Set grace only if user hasn't provided his own... */
+ dm->dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
+ }
+ if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit)
+ clear_bit(DQ_FAKE_B, &dquot->dq_flags);
+ else
+ set_bit(DQ_FAKE_B, &dquot->dq_flags);
+ spin_unlock(&dq_data_lock);
+ mark_dquot_dirty(dquot);
+}
+
+int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
+{
+ struct dquot *dquot;
+
+ down(&sb_dqopt(sb)->dqonoff_sem);
+ if (!(dquot = dqget(sb, id, type))) {
+ up(&sb_dqopt(sb)->dqonoff_sem);
+ return -ESRCH;
+ }
+ do_set_dqblk(dquot, di);
+ dqput(dquot);
+ up(&sb_dqopt(sb)->dqonoff_sem);
+ return 0;
+}
+
+/* Generic routine for getting common part of quota file information */
+int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
+{
+ struct mem_dqinfo *mi;
+
+ down(&sb_dqopt(sb)->dqonoff_sem);
+ if (!sb_has_quota_enabled(sb, type)) {
+ up(&sb_dqopt(sb)->dqonoff_sem);
+ return -ESRCH;
+ }
+ mi = sb_dqopt(sb)->info + type;
+ spin_lock(&dq_data_lock);
+ ii->dqi_bgrace = mi->dqi_bgrace;
+ ii->dqi_igrace = mi->dqi_igrace;
+ ii->dqi_flags = mi->dqi_flags & DQF_MASK;
+ ii->dqi_valid = IIF_ALL;
+ spin_unlock(&dq_data_lock);
+ up(&sb_dqopt(sb)->dqonoff_sem);
+ return 0;
+}
+
+/* Generic routine for setting common part of quota file information */
+int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
+{
+ struct mem_dqinfo *mi;
+
+ down(&sb_dqopt(sb)->dqonoff_sem);
+ if (!sb_has_quota_enabled(sb, type)) {
+ up(&sb_dqopt(sb)->dqonoff_sem);
+ return -ESRCH;
+ }
+ mi = sb_dqopt(sb)->info + type;
+ spin_lock(&dq_data_lock);
+ if (ii->dqi_valid & IIF_BGRACE)
+ mi->dqi_bgrace = ii->dqi_bgrace;
+ if (ii->dqi_valid & IIF_IGRACE)
+ mi->dqi_igrace = ii->dqi_igrace;
+ if (ii->dqi_valid & IIF_FLAGS)
+ mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | (ii->dqi_flags & DQF_MASK);
+ spin_unlock(&dq_data_lock);
+ mark_info_dirty(sb, type);
+ /* Force write to disk */
+ sb->dq_op->write_info(sb, type);
+ up(&sb_dqopt(sb)->dqonoff_sem);
+ return 0;
+}
+
+struct quotactl_ops vfs_quotactl_ops = {
+ .quota_on = vfs_quota_on,
+ .quota_off = vfs_quota_off,
+ .quota_sync = vfs_quota_sync,
+ .get_info = vfs_get_dqinfo,
+ .set_info = vfs_set_dqinfo,
+ .get_dqblk = vfs_get_dqblk,
+ .set_dqblk = vfs_set_dqblk
+};
+
+static ctl_table fs_dqstats_table[] = {
+ {
+ .ctl_name = FS_DQ_LOOKUPS,
+ .procname = "lookups",
+ .data = &dqstats.lookups,
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = FS_DQ_DROPS,
+ .procname = "drops",
+ .data = &dqstats.drops,
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = FS_DQ_READS,
+ .procname = "reads",
+ .data = &dqstats.reads,
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = FS_DQ_WRITES,
+ .procname = "writes",
+ .data = &dqstats.writes,
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = FS_DQ_CACHE_HITS,
+ .procname = "cache_hits",
+ .data = &dqstats.cache_hits,
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = FS_DQ_ALLOCATED,
+ .procname = "allocated_dquots",
+ .data = &dqstats.allocated_dquots,
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = FS_DQ_FREE,
+ .procname = "free_dquots",
+ .data = &dqstats.free_dquots,
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = FS_DQ_SYNCS,
+ .procname = "syncs",
+ .data = &dqstats.syncs,
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = FS_DQ_WARNINGS,
+ .procname = "warnings",
+ .data = &flag_print_warnings,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ { .ctl_name = 0 },
+};
+
+static ctl_table fs_table[] = {
+ {
+ .ctl_name = FS_DQSTATS,
+ .procname = "quota",
+ .mode = 0555,
+ .child = fs_dqstats_table,
+ },
+ { .ctl_name = 0 },
+};
+
+static ctl_table sys_table[] = {
+ {
+ .ctl_name = CTL_FS,
+ .procname = "fs",
+ .mode = 0555,
+ .child = fs_table,
+ },
+ { .ctl_name = 0 },
+};
+
+static int __init dquot_init(void)
+{
+ int i;
+ unsigned long nr_hash, order;
+
+ printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
+
+ register_sysctl_table(sys_table, 0);
+
+ dquot_cachep = kmem_cache_create("dquot",
+ sizeof(struct dquot), sizeof(unsigned long) * 4,
+ SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_PANIC,
+ NULL, NULL);
+
+ order = 0;
+ dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
+ if (!dquot_hash)
+ panic("Cannot create dquot hash table");
+
+ /* Find power-of-two hlist_heads which can fit into allocation */
+ nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
+ dq_hash_bits = 0;
+ do {
+ dq_hash_bits++;
+ } while (nr_hash >> dq_hash_bits);
+ dq_hash_bits--;
+
+ nr_hash = 1UL << dq_hash_bits;
+ dq_hash_mask = nr_hash - 1;
+ for (i = 0; i < nr_hash; i++)
+ INIT_HLIST_HEAD(dquot_hash + i);
+
+ printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
+ nr_hash, order, (PAGE_SIZE << order));
+
+ set_shrinker(DEFAULT_SEEKS, shrink_dqcache_memory);
+
+ return 0;
+}
+module_init(dquot_init);
+
+EXPORT_SYMBOL(register_quota_format);
+EXPORT_SYMBOL(unregister_quota_format);
+EXPORT_SYMBOL(dqstats);
+EXPORT_SYMBOL(dq_data_lock);
+EXPORT_SYMBOL(vfs_quota_on);
+EXPORT_SYMBOL(vfs_quota_on_mount);
+EXPORT_SYMBOL(vfs_quota_off);
+EXPORT_SYMBOL(vfs_quota_sync);
+EXPORT_SYMBOL(vfs_get_dqinfo);
+EXPORT_SYMBOL(vfs_set_dqinfo);
+EXPORT_SYMBOL(vfs_get_dqblk);
+EXPORT_SYMBOL(vfs_set_dqblk);
+EXPORT_SYMBOL(dquot_commit);
+EXPORT_SYMBOL(dquot_commit_info);
+EXPORT_SYMBOL(dquot_acquire);
+EXPORT_SYMBOL(dquot_release);
+EXPORT_SYMBOL(dquot_mark_dquot_dirty);
+EXPORT_SYMBOL(dquot_initialize);
+EXPORT_SYMBOL(dquot_drop);
+EXPORT_SYMBOL(dquot_alloc_space);
+EXPORT_SYMBOL(dquot_alloc_inode);
+EXPORT_SYMBOL(dquot_free_space);
+EXPORT_SYMBOL(dquot_free_inode);
+EXPORT_SYMBOL(dquot_transfer);