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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /fs/quota/dquot.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/quota/dquot.c')
-rw-r--r--fs/quota/dquot.c3024
1 files changed, 3024 insertions, 0 deletions
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
new file mode 100644
index 0000000000..023b91b4e1
--- /dev/null
+++ b/fs/quota/dquot.c
@@ -0,0 +1,3024 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Implementation of the diskquota system for the LINUX operating system. QUOTA
+ * is implemented using the BSD system call interface as the means of
+ * communication with the user level. This file contains the generic routines
+ * called by the different filesystems on allocation of an inode or block.
+ * These routines take care of the administration needed to have a consistent
+ * diskquota tracking system. The ideas of both user and group quotas are based
+ * on the Melbourne quota system as used on BSD derived systems. The internal
+ * implementation is based on one of the several variants of the LINUX
+ * inode-subsystem with added complexity of the diskquota system.
+ *
+ * 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/sched.h>
+#include <linux/cred.h>
+#include <linux/kmod.h>
+#include <linux/namei.h>
+#include <linux/capability.h>
+#include <linux/quotaops.h>
+#include <linux/blkdev.h>
+#include <linux/sched/mm.h>
+#include "../internal.h" /* ugh */
+
+#include <linux/uaccess.h>
+
+/*
+ * There are five quota SMP locks:
+ * * dq_list_lock protects all lists with quotas and quota formats.
+ * * dquot->dq_dqb_lock protects data from dq_dqb
+ * * inode->i_lock protects inode->i_blocks, i_bytes and also guards
+ * consistency of dquot->dq_dqb with inode->i_blocks, i_bytes so that
+ * dquot_transfer() can stabilize amount it transfers
+ * * dq_data_lock protects mem_dqinfo structures and modifications of dquot
+ * pointers in the inode
+ * * dq_state_lock protects modifications of quota state (on quotaon and
+ * quotaoff) and readers who care about latest values take it as well.
+ *
+ * The spinlock ordering is hence:
+ * dq_data_lock > dq_list_lock > i_lock > dquot->dq_dqb_lock,
+ * dq_list_lock > dq_state_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
+ *
+ * Operation accessing dquots via inode pointers are protected by dquot_srcu.
+ * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and
+ * synchronize_srcu(&dquot_srcu) is called after clearing pointers from
+ * inode and before dropping dquot references to avoid use of dquots after
+ * they are freed. dq_data_lock is used to serialize the pointer setting and
+ * clearing operations.
+ * Special care needs to be taken about S_NOQUOTA inode flag (marking that
+ * inode is a quota file). Functions adding pointers from inode to dquots have
+ * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they
+ * have to do all pointer modifications before dropping dq_data_lock. This makes
+ * sure they cannot race with quotaon which first sets S_NOQUOTA flag and
+ * then drops all pointers to dquots from an inode.
+ *
+ * Each dquot has its dq_lock mutex. Dquot is locked when it is being read to
+ * memory (or space for it is being allocated) on the first dqget(), when it is
+ * being written out, and when it is being released on the last dqput(). The
+ * allocation and release operations are serialized by the dq_lock and by
+ * checking the use count in dquot_release().
+ *
+ * Lock ordering (including related VFS locks) is the following:
+ * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_sem
+ */
+
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
+EXPORT_SYMBOL(dq_data_lock);
+DEFINE_STATIC_SRCU(dquot_srcu);
+
+static DECLARE_WAIT_QUEUE_HEAD(dquot_ref_wq);
+
+void __quota_error(struct super_block *sb, const char *func,
+ const char *fmt, ...)
+{
+ if (printk_ratelimit()) {
+ va_list args;
+ struct va_format vaf;
+
+ va_start(args, fmt);
+
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ printk(KERN_ERR "Quota error (device %s): %s: %pV\n",
+ sb->s_id, func, &vaf);
+
+ va_end(args);
+ }
+}
+EXPORT_SYMBOL(__quota_error);
+
+#if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING)
+static char *quotatypes[] = INITQFNAMES;
+#endif
+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;
+}
+EXPORT_SYMBOL(register_quota_format);
+
+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);
+}
+EXPORT_SYMBOL(unregister_quota_format);
+
+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 five lists for dquot management: the inuse_list,
+ * releasing_dquots, free_dquots, dqi_dirty_list, and dquot_hash[] array.
+ * A single dquot structure may be on some of those 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.
+ *
+ * When the last reference of a dquot is dropped, the dquot is added to
+ * releasing_dquots. We'll then queue work item which will call
+ * synchronize_srcu() and after that perform the final cleanup of all the
+ * dquots on the list. Each cleaned up dquot is moved to free_dquots list.
+ * Both releasing_dquots and free_dquots use the dq_free list_head in the dquot
+ * struct.
+ *
+ * Unused and cleaned up dquots are in the free_dquots list 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.
+ *
+ * Dirty dquots are added to the dqi_dirty_list of quota_info when mark
+ * dirtied, and this list is searched when writing dirty dquots back to
+ * quota file. Note that some filesystems do dirty dquot tracking on their
+ * own (e.g. in a journal) and thus don't use dqi_dirty_list.
+ *
+ * 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 LIST_HEAD(releasing_dquots);
+static unsigned int dq_hash_bits, dq_hash_mask;
+static struct hlist_head *dquot_hash;
+
+struct dqstats dqstats;
+EXPORT_SYMBOL(dqstats);
+
+static qsize_t inode_get_rsv_space(struct inode *inode);
+static qsize_t __inode_get_rsv_space(struct inode *inode);
+static int __dquot_initialize(struct inode *inode, int type);
+
+static void quota_release_workfn(struct work_struct *work);
+static DECLARE_DELAYED_WORK(quota_release_work, quota_release_workfn);
+
+static inline unsigned int
+hashfn(const struct super_block *sb, struct kqid qid)
+{
+ unsigned int id = from_kqid(&init_user_ns, qid);
+ int type = qid.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;
+ head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id);
+ hlist_add_head(&dquot->dq_hash, head);
+}
+
+static inline void remove_dquot_hash(struct dquot *dquot)
+{
+ hlist_del_init(&dquot->dq_hash);
+}
+
+static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
+ struct kqid qid)
+{
+ struct dquot *dquot;
+
+ hlist_for_each_entry(dquot, dquot_hash+hashent, dq_hash)
+ if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid))
+ return dquot;
+
+ return NULL;
+}
+
+/* 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_inc(DQST_FREE_DQUOTS);
+}
+
+static inline void put_releasing_dquots(struct dquot *dquot)
+{
+ list_add_tail(&dquot->dq_free, &releasing_dquots);
+ set_bit(DQ_RELEASING_B, &dquot->dq_flags);
+}
+
+static inline void remove_free_dquot(struct dquot *dquot)
+{
+ if (list_empty(&dquot->dq_free))
+ return;
+ list_del_init(&dquot->dq_free);
+ if (!test_bit(DQ_RELEASING_B, &dquot->dq_flags))
+ dqstats_dec(DQST_FREE_DQUOTS);
+ else
+ clear_bit(DQ_RELEASING_B, &dquot->dq_flags);
+}
+
+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_inc(DQST_ALLOC_DQUOTS);
+}
+
+static inline void remove_inuse(struct dquot *dquot)
+{
+ dqstats_dec(DQST_ALLOC_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);
+}
+
+static inline int dquot_active(struct dquot *dquot)
+{
+ return test_bit(DQ_ACTIVE_B, &dquot->dq_flags);
+}
+
+static inline int dquot_dirty(struct dquot *dquot)
+{
+ return test_bit(DQ_MOD_B, &dquot->dq_flags);
+}
+
+static inline int mark_dquot_dirty(struct dquot *dquot)
+{
+ return dquot->dq_sb->dq_op->mark_dirty(dquot);
+}
+
+/* Mark dquot dirty in atomic manner, and return it's old dirty flag state */
+int dquot_mark_dquot_dirty(struct dquot *dquot)
+{
+ int ret = 1;
+
+ if (!dquot_active(dquot))
+ return 0;
+
+ if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
+ return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags);
+
+ /* If quota is dirty already, we don't have to acquire dq_list_lock */
+ if (dquot_dirty(dquot))
+ return 1;
+
+ 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_id.type].dqi_dirty_list);
+ ret = 0;
+ }
+ spin_unlock(&dq_list_lock);
+ return ret;
+}
+EXPORT_SYMBOL(dquot_mark_dquot_dirty);
+
+/* Dirtify all the dquots - this can block when journalling */
+static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
+{
+ int ret, err, cnt;
+
+ ret = err = 0;
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (dquot[cnt])
+ /* Even in case of error we have to continue */
+ ret = mark_dquot_dirty(dquot[cnt]);
+ if (!err)
+ err = ret;
+ }
+ return err;
+}
+
+static inline void dqput_all(struct dquot **dquot)
+{
+ unsigned int cnt;
+
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ dqput(dquot[cnt]);
+}
+
+static inline int clear_dquot_dirty(struct dquot *dquot)
+{
+ if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
+ return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags);
+
+ spin_lock(&dq_list_lock);
+ if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) {
+ spin_unlock(&dq_list_lock);
+ return 0;
+ }
+ list_del_init(&dquot->dq_dirty);
+ spin_unlock(&dq_list_lock);
+ return 1;
+}
+
+void mark_info_dirty(struct super_block *sb, int type)
+{
+ spin_lock(&dq_data_lock);
+ sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY;
+ spin_unlock(&dq_data_lock);
+}
+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;
+ unsigned int memalloc;
+ struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+ mutex_lock(&dquot->dq_lock);
+ memalloc = memalloc_nofs_save();
+ if (!test_bit(DQ_READ_B, &dquot->dq_flags)) {
+ ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
+ if (ret < 0)
+ goto out_iolock;
+ }
+ /* Make sure flags update is visible after dquot has been filled */
+ smp_mb__before_atomic();
+ set_bit(DQ_READ_B, &dquot->dq_flags);
+ /* Instantiate dquot if needed */
+ if (!dquot_active(dquot) && !dquot->dq_off) {
+ ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
+ /* Write the info if needed */
+ if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
+ ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
+ dquot->dq_sb, dquot->dq_id.type);
+ }
+ if (ret < 0)
+ goto out_iolock;
+ if (ret2 < 0) {
+ ret = ret2;
+ goto out_iolock;
+ }
+ }
+ /*
+ * Make sure flags update is visible after on-disk struct has been
+ * allocated. Paired with smp_rmb() in dqget().
+ */
+ smp_mb__before_atomic();
+ set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
+out_iolock:
+ memalloc_nofs_restore(memalloc);
+ mutex_unlock(&dquot->dq_lock);
+ return ret;
+}
+EXPORT_SYMBOL(dquot_acquire);
+
+/*
+ * Write dquot to disk
+ */
+int dquot_commit(struct dquot *dquot)
+{
+ int ret = 0;
+ unsigned int memalloc;
+ struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+ mutex_lock(&dquot->dq_lock);
+ memalloc = memalloc_nofs_save();
+ if (!clear_dquot_dirty(dquot))
+ goto out_lock;
+ /* Inactive dquot can be only if there was error during read/init
+ * => we have better not writing it */
+ if (dquot_active(dquot))
+ ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
+ else
+ ret = -EIO;
+out_lock:
+ memalloc_nofs_restore(memalloc);
+ mutex_unlock(&dquot->dq_lock);
+ return ret;
+}
+EXPORT_SYMBOL(dquot_commit);
+
+/*
+ * Release dquot
+ */
+int dquot_release(struct dquot *dquot)
+{
+ int ret = 0, ret2 = 0;
+ unsigned int memalloc;
+ struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+ mutex_lock(&dquot->dq_lock);
+ memalloc = memalloc_nofs_save();
+ /* Check whether we are not racing with some other dqget() */
+ if (dquot_is_busy(dquot))
+ goto out_dqlock;
+ if (dqopt->ops[dquot->dq_id.type]->release_dqblk) {
+ ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot);
+ /* Write the info */
+ if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
+ ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
+ dquot->dq_sb, dquot->dq_id.type);
+ }
+ if (ret >= 0)
+ ret = ret2;
+ }
+ clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
+out_dqlock:
+ memalloc_nofs_restore(memalloc);
+ mutex_unlock(&dquot->dq_lock);
+ return ret;
+}
+EXPORT_SYMBOL(dquot_release);
+
+void dquot_destroy(struct dquot *dquot)
+{
+ kmem_cache_free(dquot_cachep, dquot);
+}
+EXPORT_SYMBOL(dquot_destroy);
+
+static inline void do_destroy_dquot(struct dquot *dquot)
+{
+ dquot->dq_sb->dq_op->destroy_dquot(dquot);
+}
+
+/* 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) or parallel quotactl call. We have to wait for such users.
+ */
+static void invalidate_dquots(struct super_block *sb, int type)
+{
+ struct dquot *dquot, *tmp;
+
+restart:
+ flush_delayed_work(&quota_release_work);
+
+ 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_id.type != type)
+ continue;
+ /* Wait for dquot users */
+ if (atomic_read(&dquot->dq_count)) {
+ atomic_inc(&dquot->dq_count);
+ 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.
+ */
+ wait_event(dquot_ref_wq,
+ atomic_read(&dquot->dq_count) == 1);
+ dqput(dquot);
+ /* At this moment dquot() need not exist (it could be
+ * reclaimed by prune_dqcache(). Hence we must
+ * restart. */
+ goto restart;
+ }
+ /*
+ * The last user already dropped its reference but dquot didn't
+ * get fully cleaned up yet. Restart the scan which flushes the
+ * work cleaning up released dquots.
+ */
+ if (test_bit(DQ_RELEASING_B, &dquot->dq_flags)) {
+ spin_unlock(&dq_list_lock);
+ 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);
+ do_destroy_dquot(dquot);
+ }
+ spin_unlock(&dq_list_lock);
+}
+
+/* Call callback for every active dquot on given filesystem */
+int dquot_scan_active(struct super_block *sb,
+ int (*fn)(struct dquot *dquot, unsigned long priv),
+ unsigned long priv)
+{
+ struct dquot *dquot, *old_dquot = NULL;
+ int ret = 0;
+
+ WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount));
+
+ spin_lock(&dq_list_lock);
+ list_for_each_entry(dquot, &inuse_list, dq_inuse) {
+ if (!dquot_active(dquot))
+ continue;
+ if (dquot->dq_sb != sb)
+ continue;
+ /* Now we have active dquot so we can just increase use count */
+ atomic_inc(&dquot->dq_count);
+ spin_unlock(&dq_list_lock);
+ dqput(old_dquot);
+ old_dquot = dquot;
+ /*
+ * ->release_dquot() can be racing with us. Our reference
+ * protects us from new calls to it so just wait for any
+ * outstanding call and recheck the DQ_ACTIVE_B after that.
+ */
+ wait_on_dquot(dquot);
+ if (dquot_active(dquot)) {
+ ret = fn(dquot, priv);
+ if (ret < 0)
+ goto out;
+ }
+ spin_lock(&dq_list_lock);
+ /* We are safe to continue now because our dquot could not
+ * be moved out of the inuse list while we hold the reference */
+ }
+ spin_unlock(&dq_list_lock);
+out:
+ dqput(old_dquot);
+ return ret;
+}
+EXPORT_SYMBOL(dquot_scan_active);
+
+static inline int dquot_write_dquot(struct dquot *dquot)
+{
+ int ret = dquot->dq_sb->dq_op->write_dquot(dquot);
+ if (ret < 0) {
+ quota_error(dquot->dq_sb, "Can't write quota structure "
+ "(error %d). Quota may get out of sync!", ret);
+ /* Clear dirty bit anyway to avoid infinite loop. */
+ clear_dquot_dirty(dquot);
+ }
+ return ret;
+}
+
+/* Write all dquot structures to quota files */
+int dquot_writeback_dquots(struct super_block *sb, int type)
+{
+ struct list_head dirty;
+ struct dquot *dquot;
+ struct quota_info *dqopt = sb_dqopt(sb);
+ int cnt;
+ int err, ret = 0;
+
+ WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount));
+
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (type != -1 && cnt != type)
+ continue;
+ if (!sb_has_quota_active(sb, cnt))
+ continue;
+ spin_lock(&dq_list_lock);
+ /* Move list away to avoid livelock. */
+ list_replace_init(&dqopt->info[cnt].dqi_dirty_list, &dirty);
+ while (!list_empty(&dirty)) {
+ dquot = list_first_entry(&dirty, struct dquot,
+ dq_dirty);
+
+ WARN_ON(!dquot_active(dquot));
+ /* If the dquot is releasing we should not touch it */
+ if (test_bit(DQ_RELEASING_B, &dquot->dq_flags)) {
+ spin_unlock(&dq_list_lock);
+ flush_delayed_work(&quota_release_work);
+ spin_lock(&dq_list_lock);
+ continue;
+ }
+
+ /* Now we have active dquot from which someone is
+ * holding reference so we can safely just increase
+ * use count */
+ dqgrab(dquot);
+ spin_unlock(&dq_list_lock);
+ err = dquot_write_dquot(dquot);
+ if (err && !ret)
+ ret = err;
+ 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_active(sb, cnt)
+ && info_dirty(&dqopt->info[cnt]))
+ sb->dq_op->write_info(sb, cnt);
+ dqstats_inc(DQST_SYNCS);
+
+ return ret;
+}
+EXPORT_SYMBOL(dquot_writeback_dquots);
+
+/* Write all dquot structures to disk and make them visible from userspace */
+int dquot_quota_sync(struct super_block *sb, int type)
+{
+ struct quota_info *dqopt = sb_dqopt(sb);
+ int cnt;
+ int ret;
+
+ ret = dquot_writeback_dquots(sb, type);
+ if (ret)
+ return ret;
+ if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
+ return 0;
+
+ /* This is not very clever (and fast) but currently I don't know about
+ * any other simple way of getting quota data to disk and we must get
+ * them there for userspace to be visible... */
+ if (sb->s_op->sync_fs) {
+ ret = sb->s_op->sync_fs(sb, 1);
+ if (ret)
+ return ret;
+ }
+ ret = sync_blockdev(sb->s_bdev);
+ if (ret)
+ return ret;
+
+ /*
+ * Now when everything is written we can discard the pagecache so
+ * that userspace sees the changes.
+ */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (type != -1 && cnt != type)
+ continue;
+ if (!sb_has_quota_active(sb, cnt))
+ continue;
+ inode_lock(dqopt->files[cnt]);
+ truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
+ inode_unlock(dqopt->files[cnt]);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(dquot_quota_sync);
+
+static unsigned long
+dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+ struct dquot *dquot;
+ unsigned long freed = 0;
+
+ spin_lock(&dq_list_lock);
+ while (!list_empty(&free_dquots) && sc->nr_to_scan) {
+ dquot = list_first_entry(&free_dquots, struct dquot, dq_free);
+ remove_dquot_hash(dquot);
+ remove_free_dquot(dquot);
+ remove_inuse(dquot);
+ do_destroy_dquot(dquot);
+ sc->nr_to_scan--;
+ freed++;
+ }
+ spin_unlock(&dq_list_lock);
+ return freed;
+}
+
+static unsigned long
+dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ return vfs_pressure_ratio(
+ percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]));
+}
+
+static struct shrinker dqcache_shrinker = {
+ .count_objects = dqcache_shrink_count,
+ .scan_objects = dqcache_shrink_scan,
+ .seeks = DEFAULT_SEEKS,
+};
+
+/*
+ * Safely release dquot and put reference to dquot.
+ */
+static void quota_release_workfn(struct work_struct *work)
+{
+ struct dquot *dquot;
+ struct list_head rls_head;
+
+ spin_lock(&dq_list_lock);
+ /* Exchange the list head to avoid livelock. */
+ list_replace_init(&releasing_dquots, &rls_head);
+ spin_unlock(&dq_list_lock);
+ synchronize_srcu(&dquot_srcu);
+
+restart:
+ spin_lock(&dq_list_lock);
+ while (!list_empty(&rls_head)) {
+ dquot = list_first_entry(&rls_head, struct dquot, dq_free);
+ WARN_ON_ONCE(atomic_read(&dquot->dq_count));
+ /*
+ * Note that DQ_RELEASING_B protects us from racing with
+ * invalidate_dquots() calls so we are safe to work with the
+ * dquot even after we drop dq_list_lock.
+ */
+ if (dquot_dirty(dquot)) {
+ spin_unlock(&dq_list_lock);
+ /* Commit dquot before releasing */
+ dquot_write_dquot(dquot);
+ goto restart;
+ }
+ if (dquot_active(dquot)) {
+ spin_unlock(&dq_list_lock);
+ dquot->dq_sb->dq_op->release_dquot(dquot);
+ goto restart;
+ }
+ /* Dquot is inactive and clean, now move it to free list */
+ remove_free_dquot(dquot);
+ put_dquot_last(dquot);
+ }
+ spin_unlock(&dq_list_lock);
+}
+
+/*
+ * Put reference to dquot
+ */
+void dqput(struct dquot *dquot)
+{
+ if (!dquot)
+ return;
+#ifdef CONFIG_QUOTA_DEBUG
+ if (!atomic_read(&dquot->dq_count)) {
+ quota_error(dquot->dq_sb, "trying to free free dquot of %s %d",
+ quotatypes[dquot->dq_id.type],
+ from_kqid(&init_user_ns, dquot->dq_id));
+ BUG();
+ }
+#endif
+ dqstats_inc(DQST_DROPS);
+
+ 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_active(dquot->dq_sb, dquot->dq_id.type) &&
+ atomic_read(&dquot->dq_count) == 1)
+ wake_up(&dquot_ref_wq);
+ spin_unlock(&dq_list_lock);
+ return;
+ }
+
+ /* Need to release dquot? */
+#ifdef CONFIG_QUOTA_DEBUG
+ /* sanity check */
+ BUG_ON(!list_empty(&dquot->dq_free));
+#endif
+ put_releasing_dquots(dquot);
+ atomic_dec(&dquot->dq_count);
+ spin_unlock(&dq_list_lock);
+ queue_delayed_work(system_unbound_wq, &quota_release_work, 1);
+}
+EXPORT_SYMBOL(dqput);
+
+struct dquot *dquot_alloc(struct super_block *sb, int type)
+{
+ return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
+}
+EXPORT_SYMBOL(dquot_alloc);
+
+static struct dquot *get_empty_dquot(struct super_block *sb, int type)
+{
+ struct dquot *dquot;
+
+ dquot = sb->dq_op->alloc_dquot(sb, type);
+ if(!dquot)
+ return NULL;
+
+ 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);
+ dquot->dq_sb = sb;
+ dquot->dq_id = make_kqid_invalid(type);
+ atomic_set(&dquot->dq_count, 1);
+ spin_lock_init(&dquot->dq_dqb_lock);
+
+ return dquot;
+}
+
+/*
+ * Get reference to dquot
+ *
+ * Locking is slightly tricky here. We are guarded from parallel quotaoff()
+ * destroying our dquot by:
+ * a) checking for quota flags under dq_list_lock and
+ * b) getting a reference to dquot before we release dq_list_lock
+ */
+struct dquot *dqget(struct super_block *sb, struct kqid qid)
+{
+ unsigned int hashent = hashfn(sb, qid);
+ struct dquot *dquot, *empty = NULL;
+
+ if (!qid_has_mapping(sb->s_user_ns, qid))
+ return ERR_PTR(-EINVAL);
+
+ if (!sb_has_quota_active(sb, qid.type))
+ return ERR_PTR(-ESRCH);
+we_slept:
+ spin_lock(&dq_list_lock);
+ spin_lock(&dq_state_lock);
+ if (!sb_has_quota_active(sb, qid.type)) {
+ spin_unlock(&dq_state_lock);
+ spin_unlock(&dq_list_lock);
+ dquot = ERR_PTR(-ESRCH);
+ goto out;
+ }
+ spin_unlock(&dq_state_lock);
+
+ dquot = find_dquot(hashent, sb, qid);
+ if (!dquot) {
+ if (!empty) {
+ spin_unlock(&dq_list_lock);
+ empty = get_empty_dquot(sb, qid.type);
+ if (!empty)
+ schedule(); /* Try to wait for a moment... */
+ goto we_slept;
+ }
+ dquot = empty;
+ empty = NULL;
+ dquot->dq_id = qid;
+ /* all dquots go on the inuse_list */
+ put_inuse(dquot);
+ /* hash it first so it can be found */
+ insert_dquot_hash(dquot);
+ spin_unlock(&dq_list_lock);
+ dqstats_inc(DQST_LOOKUPS);
+ } else {
+ if (!atomic_read(&dquot->dq_count))
+ remove_free_dquot(dquot);
+ atomic_inc(&dquot->dq_count);
+ spin_unlock(&dq_list_lock);
+ dqstats_inc(DQST_CACHE_HITS);
+ dqstats_inc(DQST_LOOKUPS);
+ }
+ /* Wait for dq_lock - after this we know that either dquot_release() is
+ * already finished or it will be canceled due to dq_count > 0 test */
+ wait_on_dquot(dquot);
+ /* Read the dquot / allocate space in quota file */
+ if (!dquot_active(dquot)) {
+ int err;
+
+ err = sb->dq_op->acquire_dquot(dquot);
+ if (err < 0) {
+ dqput(dquot);
+ dquot = ERR_PTR(err);
+ goto out;
+ }
+ }
+ /*
+ * Make sure following reads see filled structure - paired with
+ * smp_mb__before_atomic() in dquot_acquire().
+ */
+ smp_rmb();
+#ifdef CONFIG_QUOTA_DEBUG
+ BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */
+#endif
+out:
+ if (empty)
+ do_destroy_dquot(empty);
+
+ return dquot;
+}
+EXPORT_SYMBOL(dqget);
+
+static inline struct dquot **i_dquot(struct inode *inode)
+{
+ return inode->i_sb->s_op->get_dquots(inode);
+}
+
+static int dqinit_needed(struct inode *inode, int type)
+{
+ struct dquot * const *dquots;
+ int cnt;
+
+ if (IS_NOQUOTA(inode))
+ return 0;
+
+ dquots = i_dquot(inode);
+ if (type != -1)
+ return !dquots[type];
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ if (!dquots[cnt])
+ return 1;
+ return 0;
+}
+
+/* This routine is guarded by s_umount semaphore */
+static int add_dquot_ref(struct super_block *sb, int type)
+{
+ struct inode *inode, *old_inode = NULL;
+#ifdef CONFIG_QUOTA_DEBUG
+ int reserved = 0;
+#endif
+ int err = 0;
+
+ spin_lock(&sb->s_inode_list_lock);
+ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+ spin_lock(&inode->i_lock);
+ if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
+ !atomic_read(&inode->i_writecount) ||
+ !dqinit_needed(inode, type)) {
+ spin_unlock(&inode->i_lock);
+ continue;
+ }
+ __iget(inode);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&sb->s_inode_list_lock);
+
+#ifdef CONFIG_QUOTA_DEBUG
+ if (unlikely(inode_get_rsv_space(inode) > 0))
+ reserved = 1;
+#endif
+ iput(old_inode);
+ err = __dquot_initialize(inode, type);
+ if (err) {
+ iput(inode);
+ goto out;
+ }
+
+ /*
+ * We hold a reference to 'inode' so it couldn't have been
+ * removed from s_inodes list while we dropped the
+ * s_inode_list_lock. We cannot iput the inode now as we can be
+ * holding the last reference and we cannot iput it under
+ * s_inode_list_lock. So we keep the reference and iput it
+ * later.
+ */
+ old_inode = inode;
+ cond_resched();
+ spin_lock(&sb->s_inode_list_lock);
+ }
+ spin_unlock(&sb->s_inode_list_lock);
+ iput(old_inode);
+out:
+#ifdef CONFIG_QUOTA_DEBUG
+ if (reserved) {
+ quota_error(sb, "Writes happened before quota was turned on "
+ "thus quota information is probably inconsistent. "
+ "Please run quotacheck(8)");
+ }
+#endif
+ return err;
+}
+
+static void remove_dquot_ref(struct super_block *sb, int type)
+{
+ struct inode *inode;
+#ifdef CONFIG_QUOTA_DEBUG
+ int reserved = 0;
+#endif
+
+ spin_lock(&sb->s_inode_list_lock);
+ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+ /*
+ * We have to scan also I_NEW inodes because they can already
+ * have quota pointer initialized. Luckily, we need to touch
+ * only quota pointers and these have separate locking
+ * (dq_data_lock).
+ */
+ spin_lock(&dq_data_lock);
+ if (!IS_NOQUOTA(inode)) {
+ struct dquot **dquots = i_dquot(inode);
+ struct dquot *dquot = dquots[type];
+
+#ifdef CONFIG_QUOTA_DEBUG
+ if (unlikely(inode_get_rsv_space(inode) > 0))
+ reserved = 1;
+#endif
+ dquots[type] = NULL;
+ if (dquot)
+ dqput(dquot);
+ }
+ spin_unlock(&dq_data_lock);
+ }
+ spin_unlock(&sb->s_inode_list_lock);
+#ifdef CONFIG_QUOTA_DEBUG
+ if (reserved) {
+ printk(KERN_WARNING "VFS (%s): Writes happened after quota"
+ " was disabled thus quota information is probably "
+ "inconsistent. Please run quotacheck(8).\n", sb->s_id);
+ }
+#endif
+}
+
+/* Gather all references from inodes and drop them */
+static void drop_dquot_ref(struct super_block *sb, int type)
+{
+ if (sb->dq_op)
+ remove_dquot_ref(sb, type);
+}
+
+static inline
+void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
+{
+ if (dquot->dq_dqb.dqb_rsvspace >= number)
+ dquot->dq_dqb.dqb_rsvspace -= number;
+ else {
+ WARN_ON_ONCE(1);
+ dquot->dq_dqb.dqb_rsvspace = 0;
+ }
+ if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <=
+ dquot->dq_dqb.dqb_bsoftlimit)
+ dquot->dq_dqb.dqb_btime = (time64_t) 0;
+ clear_bit(DQ_BLKS_B, &dquot->dq_flags);
+}
+
+static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
+{
+ if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
+ 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 = (time64_t) 0;
+ clear_bit(DQ_INODES_B, &dquot->dq_flags);
+}
+
+static void dquot_decr_space(struct dquot *dquot, qsize_t number)
+{
+ if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
+ dquot->dq_dqb.dqb_curspace >= number)
+ dquot->dq_dqb.dqb_curspace -= number;
+ else
+ dquot->dq_dqb.dqb_curspace = 0;
+ if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <=
+ dquot->dq_dqb.dqb_bsoftlimit)
+ dquot->dq_dqb.dqb_btime = (time64_t) 0;
+ clear_bit(DQ_BLKS_B, &dquot->dq_flags);
+}
+
+struct dquot_warn {
+ struct super_block *w_sb;
+ struct kqid w_dq_id;
+ short w_type;
+};
+
+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 int need_print_warning(struct dquot_warn *warn)
+{
+ if (!flag_print_warnings)
+ return 0;
+
+ switch (warn->w_dq_id.type) {
+ case USRQUOTA:
+ return uid_eq(current_fsuid(), warn->w_dq_id.uid);
+ case GRPQUOTA:
+ return in_group_p(warn->w_dq_id.gid);
+ case PRJQUOTA:
+ return 1;
+ }
+ return 0;
+}
+
+/* Print warning to user which exceeded quota */
+static void print_warning(struct dquot_warn *warn)
+{
+ char *msg = NULL;
+ struct tty_struct *tty;
+ int warntype = warn->w_type;
+
+ if (warntype == QUOTA_NL_IHARDBELOW ||
+ warntype == QUOTA_NL_ISOFTBELOW ||
+ warntype == QUOTA_NL_BHARDBELOW ||
+ warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn))
+ return;
+
+ tty = get_current_tty();
+ if (!tty)
+ return;
+ tty_write_message(tty, warn->w_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[warn->w_dq_id.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);
+ tty_kref_put(tty);
+}
+#endif
+
+static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot,
+ int warntype)
+{
+ if (warning_issued(dquot, warntype))
+ return;
+ warn->w_type = warntype;
+ warn->w_sb = dquot->dq_sb;
+ warn->w_dq_id = dquot->dq_id;
+}
+
+/*
+ * Write warnings to the console and send warning messages over netlink.
+ *
+ * Note that this function can call into tty and networking code.
+ */
+static void flush_warnings(struct dquot_warn *warn)
+{
+ int i;
+
+ for (i = 0; i < MAXQUOTAS; i++) {
+ if (warn[i].w_type == QUOTA_NL_NOWARN)
+ continue;
+#ifdef CONFIG_PRINT_QUOTA_WARNING
+ print_warning(&warn[i]);
+#endif
+ quota_send_warning(warn[i].w_dq_id,
+ warn[i].w_sb->s_dev, warn[i].w_type);
+ }
+}
+
+static int ignore_hardlimit(struct dquot *dquot)
+{
+ struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
+
+ return capable(CAP_SYS_RESOURCE) &&
+ (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
+ !(info->dqi_flags & DQF_ROOT_SQUASH));
+}
+
+static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes,
+ struct dquot_warn *warn)
+{
+ qsize_t newinodes;
+ int ret = 0;
+
+ spin_lock(&dquot->dq_dqb_lock);
+ newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
+ if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) ||
+ test_bit(DQ_FAKE_B, &dquot->dq_flags))
+ goto add;
+
+ if (dquot->dq_dqb.dqb_ihardlimit &&
+ newinodes > dquot->dq_dqb.dqb_ihardlimit &&
+ !ignore_hardlimit(dquot)) {
+ prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN);
+ ret = -EDQUOT;
+ goto out;
+ }
+
+ if (dquot->dq_dqb.dqb_isoftlimit &&
+ newinodes > dquot->dq_dqb.dqb_isoftlimit &&
+ dquot->dq_dqb.dqb_itime &&
+ ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime &&
+ !ignore_hardlimit(dquot)) {
+ prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN);
+ ret = -EDQUOT;
+ goto out;
+ }
+
+ if (dquot->dq_dqb.dqb_isoftlimit &&
+ newinodes > dquot->dq_dqb.dqb_isoftlimit &&
+ dquot->dq_dqb.dqb_itime == 0) {
+ prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN);
+ dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() +
+ sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace;
+ }
+add:
+ dquot->dq_dqb.dqb_curinodes = newinodes;
+
+out:
+ spin_unlock(&dquot->dq_dqb_lock);
+ return ret;
+}
+
+static int dquot_add_space(struct dquot *dquot, qsize_t space,
+ qsize_t rsv_space, unsigned int flags,
+ struct dquot_warn *warn)
+{
+ qsize_t tspace;
+ struct super_block *sb = dquot->dq_sb;
+ int ret = 0;
+
+ spin_lock(&dquot->dq_dqb_lock);
+ if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) ||
+ test_bit(DQ_FAKE_B, &dquot->dq_flags))
+ goto finish;
+
+ tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
+ + space + rsv_space;
+
+ if (dquot->dq_dqb.dqb_bhardlimit &&
+ tspace > dquot->dq_dqb.dqb_bhardlimit &&
+ !ignore_hardlimit(dquot)) {
+ if (flags & DQUOT_SPACE_WARN)
+ prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN);
+ ret = -EDQUOT;
+ goto finish;
+ }
+
+ if (dquot->dq_dqb.dqb_bsoftlimit &&
+ tspace > dquot->dq_dqb.dqb_bsoftlimit &&
+ dquot->dq_dqb.dqb_btime &&
+ ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime &&
+ !ignore_hardlimit(dquot)) {
+ if (flags & DQUOT_SPACE_WARN)
+ prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN);
+ ret = -EDQUOT;
+ goto finish;
+ }
+
+ if (dquot->dq_dqb.dqb_bsoftlimit &&
+ tspace > dquot->dq_dqb.dqb_bsoftlimit &&
+ dquot->dq_dqb.dqb_btime == 0) {
+ if (flags & DQUOT_SPACE_WARN) {
+ prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN);
+ dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() +
+ sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace;
+ } else {
+ /*
+ * We don't allow preallocation to exceed softlimit so exceeding will
+ * be always printed
+ */
+ ret = -EDQUOT;
+ goto finish;
+ }
+ }
+finish:
+ /*
+ * We have to be careful and go through warning generation & grace time
+ * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it
+ * only here...
+ */
+ if (flags & DQUOT_SPACE_NOFAIL)
+ ret = 0;
+ if (!ret) {
+ dquot->dq_dqb.dqb_rsvspace += rsv_space;
+ dquot->dq_dqb.dqb_curspace += space;
+ }
+ spin_unlock(&dquot->dq_dqb_lock);
+ return ret;
+}
+
+static int info_idq_free(struct dquot *dquot, qsize_t inodes)
+{
+ qsize_t newinodes;
+
+ if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
+ dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
+ !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type))
+ return QUOTA_NL_NOWARN;
+
+ newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
+ if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
+ return QUOTA_NL_ISOFTBELOW;
+ if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
+ newinodes < dquot->dq_dqb.dqb_ihardlimit)
+ return QUOTA_NL_IHARDBELOW;
+ return QUOTA_NL_NOWARN;
+}
+
+static int info_bdq_free(struct dquot *dquot, qsize_t space)
+{
+ qsize_t tspace;
+
+ tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace;
+
+ if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
+ tspace <= dquot->dq_dqb.dqb_bsoftlimit)
+ return QUOTA_NL_NOWARN;
+
+ if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
+ return QUOTA_NL_BSOFTBELOW;
+ if (tspace >= dquot->dq_dqb.dqb_bhardlimit &&
+ tspace - space < dquot->dq_dqb.dqb_bhardlimit)
+ return QUOTA_NL_BHARDBELOW;
+ return QUOTA_NL_NOWARN;
+}
+
+static int inode_quota_active(const struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+
+ if (IS_NOQUOTA(inode))
+ return 0;
+ return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
+}
+
+/*
+ * Initialize quota pointers in inode
+ *
+ * It is better to call this function outside of any transaction as it
+ * might need a lot of space in journal for dquot structure allocation.
+ */
+static int __dquot_initialize(struct inode *inode, int type)
+{
+ int cnt, init_needed = 0;
+ struct dquot **dquots, *got[MAXQUOTAS] = {};
+ struct super_block *sb = inode->i_sb;
+ qsize_t rsv;
+ int ret = 0;
+
+ if (!inode_quota_active(inode))
+ return 0;
+
+ dquots = i_dquot(inode);
+
+ /* First get references to structures we might need. */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ struct kqid qid;
+ kprojid_t projid;
+ int rc;
+ struct dquot *dquot;
+
+ if (type != -1 && cnt != type)
+ continue;
+ /*
+ * The i_dquot should have been initialized in most cases,
+ * we check it without locking here to avoid unnecessary
+ * dqget()/dqput() calls.
+ */
+ if (dquots[cnt])
+ continue;
+
+ if (!sb_has_quota_active(sb, cnt))
+ continue;
+
+ init_needed = 1;
+
+ switch (cnt) {
+ case USRQUOTA:
+ qid = make_kqid_uid(inode->i_uid);
+ break;
+ case GRPQUOTA:
+ qid = make_kqid_gid(inode->i_gid);
+ break;
+ case PRJQUOTA:
+ rc = inode->i_sb->dq_op->get_projid(inode, &projid);
+ if (rc)
+ continue;
+ qid = make_kqid_projid(projid);
+ break;
+ }
+ dquot = dqget(sb, qid);
+ if (IS_ERR(dquot)) {
+ /* We raced with somebody turning quotas off... */
+ if (PTR_ERR(dquot) != -ESRCH) {
+ ret = PTR_ERR(dquot);
+ goto out_put;
+ }
+ dquot = NULL;
+ }
+ got[cnt] = dquot;
+ }
+
+ /* All required i_dquot has been initialized */
+ if (!init_needed)
+ return 0;
+
+ spin_lock(&dq_data_lock);
+ if (IS_NOQUOTA(inode))
+ goto out_lock;
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (type != -1 && cnt != type)
+ continue;
+ /* Avoid races with quotaoff() */
+ if (!sb_has_quota_active(sb, cnt))
+ continue;
+ /* We could race with quotaon or dqget() could have failed */
+ if (!got[cnt])
+ continue;
+ if (!dquots[cnt]) {
+ dquots[cnt] = got[cnt];
+ got[cnt] = NULL;
+ /*
+ * Make quota reservation system happy if someone
+ * did a write before quota was turned on
+ */
+ rsv = inode_get_rsv_space(inode);
+ if (unlikely(rsv)) {
+ spin_lock(&inode->i_lock);
+ /* Get reservation again under proper lock */
+ rsv = __inode_get_rsv_space(inode);
+ spin_lock(&dquots[cnt]->dq_dqb_lock);
+ dquots[cnt]->dq_dqb.dqb_rsvspace += rsv;
+ spin_unlock(&dquots[cnt]->dq_dqb_lock);
+ spin_unlock(&inode->i_lock);
+ }
+ }
+ }
+out_lock:
+ spin_unlock(&dq_data_lock);
+out_put:
+ /* Drop unused references */
+ dqput_all(got);
+
+ return ret;
+}
+
+int dquot_initialize(struct inode *inode)
+{
+ return __dquot_initialize(inode, -1);
+}
+EXPORT_SYMBOL(dquot_initialize);
+
+bool dquot_initialize_needed(struct inode *inode)
+{
+ struct dquot **dquots;
+ int i;
+
+ if (!inode_quota_active(inode))
+ return false;
+
+ dquots = i_dquot(inode);
+ for (i = 0; i < MAXQUOTAS; i++)
+ if (!dquots[i] && sb_has_quota_active(inode->i_sb, i))
+ return true;
+ return false;
+}
+EXPORT_SYMBOL(dquot_initialize_needed);
+
+/*
+ * Release all quotas referenced by inode.
+ *
+ * This function only be called on inode free or converting
+ * a file to quota file, no other users for the i_dquot in
+ * both cases, so we needn't call synchronize_srcu() after
+ * clearing i_dquot.
+ */
+static void __dquot_drop(struct inode *inode)
+{
+ int cnt;
+ struct dquot **dquots = i_dquot(inode);
+ struct dquot *put[MAXQUOTAS];
+
+ spin_lock(&dq_data_lock);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ put[cnt] = dquots[cnt];
+ dquots[cnt] = NULL;
+ }
+ spin_unlock(&dq_data_lock);
+ dqput_all(put);
+}
+
+void dquot_drop(struct inode *inode)
+{
+ struct dquot * const *dquots;
+ int cnt;
+
+ if (IS_NOQUOTA(inode))
+ return;
+
+ /*
+ * Test before calling to rule out calls from proc and such
+ * where we are not allowed to block. Note that this is
+ * actually reliable test even without the lock - the caller
+ * must assure that nobody can come after the DQUOT_DROP and
+ * add quota pointers back anyway.
+ */
+ dquots = i_dquot(inode);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (dquots[cnt])
+ break;
+ }
+
+ if (cnt < MAXQUOTAS)
+ __dquot_drop(inode);
+}
+EXPORT_SYMBOL(dquot_drop);
+
+/*
+ * inode_reserved_space is managed internally by quota, and protected by
+ * i_lock similar to i_blocks+i_bytes.
+ */
+static qsize_t *inode_reserved_space(struct inode * inode)
+{
+ /* Filesystem must explicitly define it's own method in order to use
+ * quota reservation interface */
+ BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
+ return inode->i_sb->dq_op->get_reserved_space(inode);
+}
+
+static qsize_t __inode_get_rsv_space(struct inode *inode)
+{
+ if (!inode->i_sb->dq_op->get_reserved_space)
+ return 0;
+ return *inode_reserved_space(inode);
+}
+
+static qsize_t inode_get_rsv_space(struct inode *inode)
+{
+ qsize_t ret;
+
+ if (!inode->i_sb->dq_op->get_reserved_space)
+ return 0;
+ spin_lock(&inode->i_lock);
+ ret = __inode_get_rsv_space(inode);
+ spin_unlock(&inode->i_lock);
+ return ret;
+}
+
+/*
+ * This functions updates 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 helpers 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 flags)
+{
+ int cnt, ret = 0, index;
+ struct dquot_warn warn[MAXQUOTAS];
+ int reserve = flags & DQUOT_SPACE_RESERVE;
+ struct dquot **dquots;
+
+ if (!inode_quota_active(inode)) {
+ if (reserve) {
+ spin_lock(&inode->i_lock);
+ *inode_reserved_space(inode) += number;
+ spin_unlock(&inode->i_lock);
+ } else {
+ inode_add_bytes(inode, number);
+ }
+ goto out;
+ }
+
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ warn[cnt].w_type = QUOTA_NL_NOWARN;
+
+ dquots = i_dquot(inode);
+ index = srcu_read_lock(&dquot_srcu);
+ spin_lock(&inode->i_lock);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (!dquots[cnt])
+ continue;
+ if (reserve) {
+ ret = dquot_add_space(dquots[cnt], 0, number, flags,
+ &warn[cnt]);
+ } else {
+ ret = dquot_add_space(dquots[cnt], number, 0, flags,
+ &warn[cnt]);
+ }
+ if (ret) {
+ /* Back out changes we already did */
+ for (cnt--; cnt >= 0; cnt--) {
+ if (!dquots[cnt])
+ continue;
+ spin_lock(&dquots[cnt]->dq_dqb_lock);
+ if (reserve)
+ dquot_free_reserved_space(dquots[cnt],
+ number);
+ else
+ dquot_decr_space(dquots[cnt], number);
+ spin_unlock(&dquots[cnt]->dq_dqb_lock);
+ }
+ spin_unlock(&inode->i_lock);
+ goto out_flush_warn;
+ }
+ }
+ if (reserve)
+ *inode_reserved_space(inode) += number;
+ else
+ __inode_add_bytes(inode, number);
+ spin_unlock(&inode->i_lock);
+
+ if (reserve)
+ goto out_flush_warn;
+ mark_all_dquot_dirty(dquots);
+out_flush_warn:
+ srcu_read_unlock(&dquot_srcu, index);
+ flush_warnings(warn);
+out:
+ return ret;
+}
+EXPORT_SYMBOL(__dquot_alloc_space);
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+int dquot_alloc_inode(struct inode *inode)
+{
+ int cnt, ret = 0, index;
+ struct dquot_warn warn[MAXQUOTAS];
+ struct dquot * const *dquots;
+
+ if (!inode_quota_active(inode))
+ return 0;
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ warn[cnt].w_type = QUOTA_NL_NOWARN;
+
+ dquots = i_dquot(inode);
+ index = srcu_read_lock(&dquot_srcu);
+ spin_lock(&inode->i_lock);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (!dquots[cnt])
+ continue;
+ ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]);
+ if (ret) {
+ for (cnt--; cnt >= 0; cnt--) {
+ if (!dquots[cnt])
+ continue;
+ /* Back out changes we already did */
+ spin_lock(&dquots[cnt]->dq_dqb_lock);
+ dquot_decr_inodes(dquots[cnt], 1);
+ spin_unlock(&dquots[cnt]->dq_dqb_lock);
+ }
+ goto warn_put_all;
+ }
+ }
+
+warn_put_all:
+ spin_unlock(&inode->i_lock);
+ if (ret == 0)
+ mark_all_dquot_dirty(dquots);
+ srcu_read_unlock(&dquot_srcu, index);
+ flush_warnings(warn);
+ return ret;
+}
+EXPORT_SYMBOL(dquot_alloc_inode);
+
+/*
+ * Convert in-memory reserved quotas to real consumed quotas
+ */
+int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
+{
+ struct dquot **dquots;
+ int cnt, index;
+
+ if (!inode_quota_active(inode)) {
+ spin_lock(&inode->i_lock);
+ *inode_reserved_space(inode) -= number;
+ __inode_add_bytes(inode, number);
+ spin_unlock(&inode->i_lock);
+ return 0;
+ }
+
+ dquots = i_dquot(inode);
+ index = srcu_read_lock(&dquot_srcu);
+ spin_lock(&inode->i_lock);
+ /* Claim reserved quotas to allocated quotas */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (dquots[cnt]) {
+ struct dquot *dquot = dquots[cnt];
+
+ spin_lock(&dquot->dq_dqb_lock);
+ if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number))
+ number = dquot->dq_dqb.dqb_rsvspace;
+ dquot->dq_dqb.dqb_curspace += number;
+ dquot->dq_dqb.dqb_rsvspace -= number;
+ spin_unlock(&dquot->dq_dqb_lock);
+ }
+ }
+ /* Update inode bytes */
+ *inode_reserved_space(inode) -= number;
+ __inode_add_bytes(inode, number);
+ spin_unlock(&inode->i_lock);
+ mark_all_dquot_dirty(dquots);
+ srcu_read_unlock(&dquot_srcu, index);
+ return 0;
+}
+EXPORT_SYMBOL(dquot_claim_space_nodirty);
+
+/*
+ * Convert allocated space back to in-memory reserved quotas
+ */
+void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number)
+{
+ struct dquot **dquots;
+ int cnt, index;
+
+ if (!inode_quota_active(inode)) {
+ spin_lock(&inode->i_lock);
+ *inode_reserved_space(inode) += number;
+ __inode_sub_bytes(inode, number);
+ spin_unlock(&inode->i_lock);
+ return;
+ }
+
+ dquots = i_dquot(inode);
+ index = srcu_read_lock(&dquot_srcu);
+ spin_lock(&inode->i_lock);
+ /* Claim reserved quotas to allocated quotas */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (dquots[cnt]) {
+ struct dquot *dquot = dquots[cnt];
+
+ spin_lock(&dquot->dq_dqb_lock);
+ if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number))
+ number = dquot->dq_dqb.dqb_curspace;
+ dquot->dq_dqb.dqb_rsvspace += number;
+ dquot->dq_dqb.dqb_curspace -= number;
+ spin_unlock(&dquot->dq_dqb_lock);
+ }
+ }
+ /* Update inode bytes */
+ *inode_reserved_space(inode) += number;
+ __inode_sub_bytes(inode, number);
+ spin_unlock(&inode->i_lock);
+ mark_all_dquot_dirty(dquots);
+ srcu_read_unlock(&dquot_srcu, index);
+ return;
+}
+EXPORT_SYMBOL(dquot_reclaim_space_nodirty);
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
+{
+ unsigned int cnt;
+ struct dquot_warn warn[MAXQUOTAS];
+ struct dquot **dquots;
+ int reserve = flags & DQUOT_SPACE_RESERVE, index;
+
+ if (!inode_quota_active(inode)) {
+ if (reserve) {
+ spin_lock(&inode->i_lock);
+ *inode_reserved_space(inode) -= number;
+ spin_unlock(&inode->i_lock);
+ } else {
+ inode_sub_bytes(inode, number);
+ }
+ return;
+ }
+
+ dquots = i_dquot(inode);
+ index = srcu_read_lock(&dquot_srcu);
+ spin_lock(&inode->i_lock);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ int wtype;
+
+ warn[cnt].w_type = QUOTA_NL_NOWARN;
+ if (!dquots[cnt])
+ continue;
+ spin_lock(&dquots[cnt]->dq_dqb_lock);
+ wtype = info_bdq_free(dquots[cnt], number);
+ if (wtype != QUOTA_NL_NOWARN)
+ prepare_warning(&warn[cnt], dquots[cnt], wtype);
+ if (reserve)
+ dquot_free_reserved_space(dquots[cnt], number);
+ else
+ dquot_decr_space(dquots[cnt], number);
+ spin_unlock(&dquots[cnt]->dq_dqb_lock);
+ }
+ if (reserve)
+ *inode_reserved_space(inode) -= number;
+ else
+ __inode_sub_bytes(inode, number);
+ spin_unlock(&inode->i_lock);
+
+ if (reserve)
+ goto out_unlock;
+ mark_all_dquot_dirty(dquots);
+out_unlock:
+ srcu_read_unlock(&dquot_srcu, index);
+ flush_warnings(warn);
+}
+EXPORT_SYMBOL(__dquot_free_space);
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+void dquot_free_inode(struct inode *inode)
+{
+ unsigned int cnt;
+ struct dquot_warn warn[MAXQUOTAS];
+ struct dquot * const *dquots;
+ int index;
+
+ if (!inode_quota_active(inode))
+ return;
+
+ dquots = i_dquot(inode);
+ index = srcu_read_lock(&dquot_srcu);
+ spin_lock(&inode->i_lock);
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ int wtype;
+
+ warn[cnt].w_type = QUOTA_NL_NOWARN;
+ if (!dquots[cnt])
+ continue;
+ spin_lock(&dquots[cnt]->dq_dqb_lock);
+ wtype = info_idq_free(dquots[cnt], 1);
+ if (wtype != QUOTA_NL_NOWARN)
+ prepare_warning(&warn[cnt], dquots[cnt], wtype);
+ dquot_decr_inodes(dquots[cnt], 1);
+ spin_unlock(&dquots[cnt]->dq_dqb_lock);
+ }
+ spin_unlock(&inode->i_lock);
+ mark_all_dquot_dirty(dquots);
+ srcu_read_unlock(&dquot_srcu, index);
+ flush_warnings(warn);
+}
+EXPORT_SYMBOL(dquot_free_inode);
+
+/*
+ * Transfer the number of inode and blocks from one diskquota to an other.
+ * On success, dquot references in transfer_to are consumed and references
+ * to original dquots that need to be released are placed there. On failure,
+ * references are kept untouched.
+ *
+ * This operation can block, but only after everything is updated
+ * A transaction must be started when entering this function.
+ *
+ * We are holding reference on transfer_from & transfer_to, no need to
+ * protect them by srcu_read_lock().
+ */
+int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
+{
+ qsize_t cur_space;
+ qsize_t rsv_space = 0;
+ qsize_t inode_usage = 1;
+ struct dquot *transfer_from[MAXQUOTAS] = {};
+ int cnt, ret = 0;
+ char is_valid[MAXQUOTAS] = {};
+ struct dquot_warn warn_to[MAXQUOTAS];
+ struct dquot_warn warn_from_inodes[MAXQUOTAS];
+ struct dquot_warn warn_from_space[MAXQUOTAS];
+
+ if (IS_NOQUOTA(inode))
+ return 0;
+
+ if (inode->i_sb->dq_op->get_inode_usage) {
+ ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage);
+ if (ret)
+ return ret;
+ }
+
+ /* Initialize the arrays */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ warn_to[cnt].w_type = QUOTA_NL_NOWARN;
+ warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN;
+ warn_from_space[cnt].w_type = QUOTA_NL_NOWARN;
+ }
+
+ spin_lock(&dq_data_lock);
+ spin_lock(&inode->i_lock);
+ if (IS_NOQUOTA(inode)) { /* File without quota accounting? */
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&dq_data_lock);
+ return 0;
+ }
+ cur_space = __inode_get_bytes(inode);
+ rsv_space = __inode_get_rsv_space(inode);
+ /*
+ * Build the transfer_from list, check limits, and update usage in
+ * the target structures.
+ */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ /*
+ * Skip changes for same uid or gid or for turned off quota-type.
+ */
+ if (!transfer_to[cnt])
+ continue;
+ /* Avoid races with quotaoff() */
+ if (!sb_has_quota_active(inode->i_sb, cnt))
+ continue;
+ is_valid[cnt] = 1;
+ transfer_from[cnt] = i_dquot(inode)[cnt];
+ ret = dquot_add_inodes(transfer_to[cnt], inode_usage,
+ &warn_to[cnt]);
+ if (ret)
+ goto over_quota;
+ ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space,
+ DQUOT_SPACE_WARN, &warn_to[cnt]);
+ if (ret) {
+ spin_lock(&transfer_to[cnt]->dq_dqb_lock);
+ dquot_decr_inodes(transfer_to[cnt], inode_usage);
+ spin_unlock(&transfer_to[cnt]->dq_dqb_lock);
+ goto over_quota;
+ }
+ }
+
+ /* Decrease usage for source structures and update quota pointers */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (!is_valid[cnt])
+ continue;
+ /* Due to IO error we might not have transfer_from[] structure */
+ if (transfer_from[cnt]) {
+ int wtype;
+
+ spin_lock(&transfer_from[cnt]->dq_dqb_lock);
+ wtype = info_idq_free(transfer_from[cnt], inode_usage);
+ if (wtype != QUOTA_NL_NOWARN)
+ prepare_warning(&warn_from_inodes[cnt],
+ transfer_from[cnt], wtype);
+ wtype = info_bdq_free(transfer_from[cnt],
+ cur_space + rsv_space);
+ if (wtype != QUOTA_NL_NOWARN)
+ prepare_warning(&warn_from_space[cnt],
+ transfer_from[cnt], wtype);
+ dquot_decr_inodes(transfer_from[cnt], inode_usage);
+ dquot_decr_space(transfer_from[cnt], cur_space);
+ dquot_free_reserved_space(transfer_from[cnt],
+ rsv_space);
+ spin_unlock(&transfer_from[cnt]->dq_dqb_lock);
+ }
+ i_dquot(inode)[cnt] = transfer_to[cnt];
+ }
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&dq_data_lock);
+
+ mark_all_dquot_dirty(transfer_from);
+ mark_all_dquot_dirty(transfer_to);
+ flush_warnings(warn_to);
+ flush_warnings(warn_from_inodes);
+ flush_warnings(warn_from_space);
+ /* Pass back references to put */
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ if (is_valid[cnt])
+ transfer_to[cnt] = transfer_from[cnt];
+ return 0;
+over_quota:
+ /* Back out changes we already did */
+ for (cnt--; cnt >= 0; cnt--) {
+ if (!is_valid[cnt])
+ continue;
+ spin_lock(&transfer_to[cnt]->dq_dqb_lock);
+ dquot_decr_inodes(transfer_to[cnt], inode_usage);
+ dquot_decr_space(transfer_to[cnt], cur_space);
+ dquot_free_reserved_space(transfer_to[cnt], rsv_space);
+ spin_unlock(&transfer_to[cnt]->dq_dqb_lock);
+ }
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&dq_data_lock);
+ flush_warnings(warn_to);
+ return ret;
+}
+EXPORT_SYMBOL(__dquot_transfer);
+
+/* Wrapper for transferring ownership of an inode for uid/gid only
+ * Called from FSXXX_setattr()
+ */
+int dquot_transfer(struct mnt_idmap *idmap, struct inode *inode,
+ struct iattr *iattr)
+{
+ struct dquot *transfer_to[MAXQUOTAS] = {};
+ struct dquot *dquot;
+ struct super_block *sb = inode->i_sb;
+ int ret;
+
+ if (!inode_quota_active(inode))
+ return 0;
+
+ if (i_uid_needs_update(idmap, iattr, inode)) {
+ kuid_t kuid = from_vfsuid(idmap, i_user_ns(inode),
+ iattr->ia_vfsuid);
+
+ dquot = dqget(sb, make_kqid_uid(kuid));
+ if (IS_ERR(dquot)) {
+ if (PTR_ERR(dquot) != -ESRCH) {
+ ret = PTR_ERR(dquot);
+ goto out_put;
+ }
+ dquot = NULL;
+ }
+ transfer_to[USRQUOTA] = dquot;
+ }
+ if (i_gid_needs_update(idmap, iattr, inode)) {
+ kgid_t kgid = from_vfsgid(idmap, i_user_ns(inode),
+ iattr->ia_vfsgid);
+
+ dquot = dqget(sb, make_kqid_gid(kgid));
+ if (IS_ERR(dquot)) {
+ if (PTR_ERR(dquot) != -ESRCH) {
+ ret = PTR_ERR(dquot);
+ goto out_put;
+ }
+ dquot = NULL;
+ }
+ transfer_to[GRPQUOTA] = dquot;
+ }
+ ret = __dquot_transfer(inode, transfer_to);
+out_put:
+ dqput_all(transfer_to);
+ return ret;
+}
+EXPORT_SYMBOL(dquot_transfer);
+
+/*
+ * Write info of quota file to disk
+ */
+int dquot_commit_info(struct super_block *sb, int type)
+{
+ struct quota_info *dqopt = sb_dqopt(sb);
+
+ return dqopt->ops[type]->write_file_info(sb, type);
+}
+EXPORT_SYMBOL(dquot_commit_info);
+
+int dquot_get_next_id(struct super_block *sb, struct kqid *qid)
+{
+ struct quota_info *dqopt = sb_dqopt(sb);
+
+ if (!sb_has_quota_active(sb, qid->type))
+ return -ESRCH;
+ if (!dqopt->ops[qid->type]->get_next_id)
+ return -ENOSYS;
+ return dqopt->ops[qid->type]->get_next_id(sb, qid);
+}
+EXPORT_SYMBOL(dquot_get_next_id);
+
+/*
+ * Definitions of diskquota operations.
+ */
+const struct dquot_operations dquot_operations = {
+ .write_dquot = dquot_commit,
+ .acquire_dquot = dquot_acquire,
+ .release_dquot = dquot_release,
+ .mark_dirty = dquot_mark_dquot_dirty,
+ .write_info = dquot_commit_info,
+ .alloc_dquot = dquot_alloc,
+ .destroy_dquot = dquot_destroy,
+ .get_next_id = dquot_get_next_id,
+};
+EXPORT_SYMBOL(dquot_operations);
+
+/*
+ * Generic helper for ->open on filesystems supporting disk quotas.
+ */
+int dquot_file_open(struct inode *inode, struct file *file)
+{
+ int error;
+
+ error = generic_file_open(inode, file);
+ if (!error && (file->f_mode & FMODE_WRITE))
+ error = dquot_initialize(inode);
+ return error;
+}
+EXPORT_SYMBOL(dquot_file_open);
+
+static void vfs_cleanup_quota_inode(struct super_block *sb, int type)
+{
+ struct quota_info *dqopt = sb_dqopt(sb);
+ struct inode *inode = dqopt->files[type];
+
+ if (!inode)
+ return;
+ if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
+ inode_lock(inode);
+ inode->i_flags &= ~S_NOQUOTA;
+ inode_unlock(inode);
+ }
+ dqopt->files[type] = NULL;
+ iput(inode);
+}
+
+/*
+ * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
+ */
+int dquot_disable(struct super_block *sb, int type, unsigned int flags)
+{
+ int cnt;
+ struct quota_info *dqopt = sb_dqopt(sb);
+
+ /* s_umount should be held in exclusive mode */
+ if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
+ up_read(&sb->s_umount);
+
+ /* Cannot turn off usage accounting without turning off limits, or
+ * suspend quotas and simultaneously turn quotas off. */
+ if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
+ || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
+ DQUOT_USAGE_ENABLED)))
+ return -EINVAL;
+
+ /*
+ * Skip everything if there's nothing to do. We have to do this because
+ * sometimes we are called when fill_super() failed and calling
+ * sync_fs() in such cases does no good.
+ */
+ if (!sb_any_quota_loaded(sb))
+ return 0;
+
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (type != -1 && cnt != type)
+ continue;
+ if (!sb_has_quota_loaded(sb, cnt))
+ continue;
+
+ if (flags & DQUOT_SUSPENDED) {
+ spin_lock(&dq_state_lock);
+ dqopt->flags |=
+ dquot_state_flag(DQUOT_SUSPENDED, cnt);
+ spin_unlock(&dq_state_lock);
+ } else {
+ spin_lock(&dq_state_lock);
+ dqopt->flags &= ~dquot_state_flag(flags, cnt);
+ /* Turning off suspended quotas? */
+ if (!sb_has_quota_loaded(sb, cnt) &&
+ sb_has_quota_suspended(sb, cnt)) {
+ dqopt->flags &= ~dquot_state_flag(
+ DQUOT_SUSPENDED, cnt);
+ spin_unlock(&dq_state_lock);
+ vfs_cleanup_quota_inode(sb, cnt);
+ continue;
+ }
+ spin_unlock(&dq_state_lock);
+ }
+
+ /* We still have to keep quota loaded? */
+ if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
+ continue;
+
+ /* 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);
+ dqopt->info[cnt].dqi_flags = 0;
+ dqopt->info[cnt].dqi_igrace = 0;
+ dqopt->info[cnt].dqi_bgrace = 0;
+ dqopt->ops[cnt] = NULL;
+ }
+
+ /* Skip syncing and setting flags if quota files are hidden */
+ if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
+ goto put_inodes;
+
+ /* 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 (!sb_has_quota_loaded(sb, cnt) && dqopt->files[cnt]) {
+ inode_lock(dqopt->files[cnt]);
+ truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
+ inode_unlock(dqopt->files[cnt]);
+ }
+ if (sb->s_bdev)
+ invalidate_bdev(sb->s_bdev);
+put_inodes:
+ /* We are done when suspending quotas */
+ if (flags & DQUOT_SUSPENDED)
+ return 0;
+
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+ if (!sb_has_quota_loaded(sb, cnt))
+ vfs_cleanup_quota_inode(sb, cnt);
+ return 0;
+}
+EXPORT_SYMBOL(dquot_disable);
+
+int dquot_quota_off(struct super_block *sb, int type)
+{
+ return dquot_disable(sb, type,
+ DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
+}
+EXPORT_SYMBOL(dquot_quota_off);
+
+/*
+ * Turn quotas on on a device
+ */
+
+static int vfs_setup_quota_inode(struct inode *inode, int type)
+{
+ struct super_block *sb = inode->i_sb;
+ struct quota_info *dqopt = sb_dqopt(sb);
+
+ if (is_bad_inode(inode))
+ return -EUCLEAN;
+ if (!S_ISREG(inode->i_mode))
+ return -EACCES;
+ if (IS_RDONLY(inode))
+ return -EROFS;
+ if (sb_has_quota_loaded(sb, type))
+ return -EBUSY;
+
+ /*
+ * Quota files should never be encrypted. They should be thought of as
+ * filesystem metadata, not user data. New-style internal quota files
+ * cannot be encrypted by users anyway, but old-style external quota
+ * files could potentially be incorrectly created in an encrypted
+ * directory, hence this explicit check. Some reasons why encrypted
+ * quota files don't work include: (1) some filesystems that support
+ * encryption don't handle it in their quota_read and quota_write, and
+ * (2) cleaning up encrypted quota files at unmount would need special
+ * consideration, as quota files are cleaned up later than user files.
+ */
+ if (IS_ENCRYPTED(inode))
+ return -EINVAL;
+
+ dqopt->files[type] = igrab(inode);
+ if (!dqopt->files[type])
+ return -EIO;
+ if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
+ /* 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. */
+ inode_lock(inode);
+ inode->i_flags |= S_NOQUOTA;
+ inode_unlock(inode);
+ /*
+ * When S_NOQUOTA is set, remove dquot references as no more
+ * references can be added
+ */
+ __dquot_drop(inode);
+ }
+ return 0;
+}
+
+int dquot_load_quota_sb(struct super_block *sb, int type, int format_id,
+ unsigned int flags)
+{
+ struct quota_format_type *fmt = find_quota_format(format_id);
+ struct quota_info *dqopt = sb_dqopt(sb);
+ int error;
+
+ lockdep_assert_held_write(&sb->s_umount);
+
+ /* Just unsuspend quotas? */
+ BUG_ON(flags & DQUOT_SUSPENDED);
+
+ if (!fmt)
+ return -ESRCH;
+ if (!sb->dq_op || !sb->s_qcop ||
+ (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) {
+ error = -EINVAL;
+ goto out_fmt;
+ }
+ /* Filesystems outside of init_user_ns not yet supported */
+ if (sb->s_user_ns != &init_user_ns) {
+ error = -EINVAL;
+ goto out_fmt;
+ }
+ /* Usage always has to be set... */
+ if (!(flags & DQUOT_USAGE_ENABLED)) {
+ error = -EINVAL;
+ goto out_fmt;
+ }
+ if (sb_has_quota_loaded(sb, type)) {
+ error = -EBUSY;
+ goto out_fmt;
+ }
+
+ if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
+ /* As we bypass the pagecache we must now flush all the
+ * dirty data and invalidate caches so that kernel sees
+ * changes from userspace. It is not enough to just flush
+ * the quota file since if blocksize < pagesize, invalidation
+ * of the cache could fail because of other unrelated dirty
+ * data */
+ sync_filesystem(sb);
+ invalidate_bdev(sb->s_bdev);
+ }
+
+ error = -EINVAL;
+ if (!fmt->qf_ops->check_quota_file(sb, type))
+ goto out_fmt;
+
+ dqopt->ops[type] = fmt->qf_ops;
+ dqopt->info[type].dqi_format = fmt;
+ dqopt->info[type].dqi_fmt_id = format_id;
+ INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
+ error = dqopt->ops[type]->read_file_info(sb, type);
+ if (error < 0)
+ goto out_fmt;
+ if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) {
+ spin_lock(&dq_data_lock);
+ dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
+ spin_unlock(&dq_data_lock);
+ }
+ spin_lock(&dq_state_lock);
+ dqopt->flags |= dquot_state_flag(flags, type);
+ spin_unlock(&dq_state_lock);
+
+ error = add_dquot_ref(sb, type);
+ if (error)
+ dquot_disable(sb, type,
+ DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
+
+ return error;
+out_fmt:
+ put_quota_format(fmt);
+
+ return error;
+}
+EXPORT_SYMBOL(dquot_load_quota_sb);
+
+/*
+ * More powerful function for turning on quotas on given quota inode allowing
+ * setting of individual quota flags
+ */
+int dquot_load_quota_inode(struct inode *inode, int type, int format_id,
+ unsigned int flags)
+{
+ int err;
+
+ err = vfs_setup_quota_inode(inode, type);
+ if (err < 0)
+ return err;
+ err = dquot_load_quota_sb(inode->i_sb, type, format_id, flags);
+ if (err < 0)
+ vfs_cleanup_quota_inode(inode->i_sb, type);
+ return err;
+}
+EXPORT_SYMBOL(dquot_load_quota_inode);
+
+/* Reenable quotas on remount RW */
+int dquot_resume(struct super_block *sb, int type)
+{
+ struct quota_info *dqopt = sb_dqopt(sb);
+ int ret = 0, cnt;
+ unsigned int flags;
+
+ /* s_umount should be held in exclusive mode */
+ if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
+ up_read(&sb->s_umount);
+
+ for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+ if (type != -1 && cnt != type)
+ continue;
+ if (!sb_has_quota_suspended(sb, cnt))
+ continue;
+
+ spin_lock(&dq_state_lock);
+ flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
+ DQUOT_LIMITS_ENABLED,
+ cnt);
+ dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
+ spin_unlock(&dq_state_lock);
+
+ flags = dquot_generic_flag(flags, cnt);
+ ret = dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id,
+ flags);
+ if (ret < 0)
+ vfs_cleanup_quota_inode(sb, cnt);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(dquot_resume);
+
+int dquot_quota_on(struct super_block *sb, int type, int format_id,
+ const struct path *path)
+{
+ int error = security_quota_on(path->dentry);
+ if (error)
+ return error;
+ /* Quota file not on the same filesystem? */
+ if (path->dentry->d_sb != sb)
+ error = -EXDEV;
+ else
+ error = dquot_load_quota_inode(d_inode(path->dentry), type,
+ format_id, DQUOT_USAGE_ENABLED |
+ DQUOT_LIMITS_ENABLED);
+ return error;
+}
+EXPORT_SYMBOL(dquot_quota_on);
+
+/*
+ * This function is used when filesystem needs to initialize quotas
+ * during mount time.
+ */
+int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
+ int format_id, int type)
+{
+ struct dentry *dentry;
+ int error;
+
+ dentry = lookup_positive_unlocked(qf_name, sb->s_root, strlen(qf_name));
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+
+ error = security_quota_on(dentry);
+ if (!error)
+ error = dquot_load_quota_inode(d_inode(dentry), type, format_id,
+ DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
+
+ dput(dentry);
+ return error;
+}
+EXPORT_SYMBOL(dquot_quota_on_mount);
+
+static int dquot_quota_enable(struct super_block *sb, unsigned int flags)
+{
+ int ret;
+ int type;
+ struct quota_info *dqopt = sb_dqopt(sb);
+
+ if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))
+ return -ENOSYS;
+ /* Accounting cannot be turned on while fs is mounted */
+ flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT);
+ if (!flags)
+ return -EINVAL;
+ for (type = 0; type < MAXQUOTAS; type++) {
+ if (!(flags & qtype_enforce_flag(type)))
+ continue;
+ /* Can't enforce without accounting */
+ if (!sb_has_quota_usage_enabled(sb, type)) {
+ ret = -EINVAL;
+ goto out_err;
+ }
+ if (sb_has_quota_limits_enabled(sb, type)) {
+ ret = -EBUSY;
+ goto out_err;
+ }
+ spin_lock(&dq_state_lock);
+ dqopt->flags |= dquot_state_flag(DQUOT_LIMITS_ENABLED, type);
+ spin_unlock(&dq_state_lock);
+ }
+ return 0;
+out_err:
+ /* Backout enforcement enablement we already did */
+ for (type--; type >= 0; type--) {
+ if (flags & qtype_enforce_flag(type))
+ dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
+ }
+ /* Error code translation for better compatibility with XFS */
+ if (ret == -EBUSY)
+ ret = -EEXIST;
+ return ret;
+}
+
+static int dquot_quota_disable(struct super_block *sb, unsigned int flags)
+{
+ int ret;
+ int type;
+ struct quota_info *dqopt = sb_dqopt(sb);
+
+ if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))
+ return -ENOSYS;
+ /*
+ * We don't support turning off accounting via quotactl. In principle
+ * quota infrastructure can do this but filesystems don't expect
+ * userspace to be able to do it.
+ */
+ if (flags &
+ (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT))
+ return -EOPNOTSUPP;
+
+ /* Filter out limits not enabled */
+ for (type = 0; type < MAXQUOTAS; type++)
+ if (!sb_has_quota_limits_enabled(sb, type))
+ flags &= ~qtype_enforce_flag(type);
+ /* Nothing left? */
+ if (!flags)
+ return -EEXIST;
+ for (type = 0; type < MAXQUOTAS; type++) {
+ if (flags & qtype_enforce_flag(type)) {
+ ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
+ if (ret < 0)
+ goto out_err;
+ }
+ }
+ return 0;
+out_err:
+ /* Backout enforcement disabling we already did */
+ for (type--; type >= 0; type--) {
+ if (flags & qtype_enforce_flag(type)) {
+ spin_lock(&dq_state_lock);
+ dqopt->flags |=
+ dquot_state_flag(DQUOT_LIMITS_ENABLED, type);
+ spin_unlock(&dq_state_lock);
+ }
+ }
+ return ret;
+}
+
+/* Generic routine for getting common part of quota structure */
+static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di)
+{
+ struct mem_dqblk *dm = &dquot->dq_dqb;
+
+ memset(di, 0, sizeof(*di));
+ spin_lock(&dquot->dq_dqb_lock);
+ di->d_spc_hardlimit = dm->dqb_bhardlimit;
+ di->d_spc_softlimit = dm->dqb_bsoftlimit;
+ di->d_ino_hardlimit = dm->dqb_ihardlimit;
+ di->d_ino_softlimit = dm->dqb_isoftlimit;
+ di->d_space = dm->dqb_curspace + dm->dqb_rsvspace;
+ di->d_ino_count = dm->dqb_curinodes;
+ di->d_spc_timer = dm->dqb_btime;
+ di->d_ino_timer = dm->dqb_itime;
+ spin_unlock(&dquot->dq_dqb_lock);
+}
+
+int dquot_get_dqblk(struct super_block *sb, struct kqid qid,
+ struct qc_dqblk *di)
+{
+ struct dquot *dquot;
+
+ dquot = dqget(sb, qid);
+ if (IS_ERR(dquot))
+ return PTR_ERR(dquot);
+ do_get_dqblk(dquot, di);
+ dqput(dquot);
+
+ return 0;
+}
+EXPORT_SYMBOL(dquot_get_dqblk);
+
+int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid,
+ struct qc_dqblk *di)
+{
+ struct dquot *dquot;
+ int err;
+
+ if (!sb->dq_op->get_next_id)
+ return -ENOSYS;
+ err = sb->dq_op->get_next_id(sb, qid);
+ if (err < 0)
+ return err;
+ dquot = dqget(sb, *qid);
+ if (IS_ERR(dquot))
+ return PTR_ERR(dquot);
+ do_get_dqblk(dquot, di);
+ dqput(dquot);
+
+ return 0;
+}
+EXPORT_SYMBOL(dquot_get_next_dqblk);
+
+#define VFS_QC_MASK \
+ (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \
+ QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \
+ QC_SPC_TIMER | QC_INO_TIMER)
+
+/* Generic routine for setting common part of quota structure */
+static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di)
+{
+ struct mem_dqblk *dm = &dquot->dq_dqb;
+ int check_blim = 0, check_ilim = 0;
+ struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
+
+ if (di->d_fieldmask & ~VFS_QC_MASK)
+ return -EINVAL;
+
+ if (((di->d_fieldmask & QC_SPC_SOFT) &&
+ di->d_spc_softlimit > dqi->dqi_max_spc_limit) ||
+ ((di->d_fieldmask & QC_SPC_HARD) &&
+ di->d_spc_hardlimit > dqi->dqi_max_spc_limit) ||
+ ((di->d_fieldmask & QC_INO_SOFT) &&
+ (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) ||
+ ((di->d_fieldmask & QC_INO_HARD) &&
+ (di->d_ino_hardlimit > dqi->dqi_max_ino_limit)))
+ return -ERANGE;
+
+ spin_lock(&dquot->dq_dqb_lock);
+ if (di->d_fieldmask & QC_SPACE) {
+ dm->dqb_curspace = di->d_space - dm->dqb_rsvspace;
+ check_blim = 1;
+ set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
+ }
+
+ if (di->d_fieldmask & QC_SPC_SOFT)
+ dm->dqb_bsoftlimit = di->d_spc_softlimit;
+ if (di->d_fieldmask & QC_SPC_HARD)
+ dm->dqb_bhardlimit = di->d_spc_hardlimit;
+ if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) {
+ check_blim = 1;
+ set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
+ }
+
+ if (di->d_fieldmask & QC_INO_COUNT) {
+ dm->dqb_curinodes = di->d_ino_count;
+ check_ilim = 1;
+ set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
+ }
+
+ if (di->d_fieldmask & QC_INO_SOFT)
+ dm->dqb_isoftlimit = di->d_ino_softlimit;
+ if (di->d_fieldmask & QC_INO_HARD)
+ dm->dqb_ihardlimit = di->d_ino_hardlimit;
+ if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) {
+ check_ilim = 1;
+ set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
+ }
+
+ if (di->d_fieldmask & QC_SPC_TIMER) {
+ dm->dqb_btime = di->d_spc_timer;
+ check_blim = 1;
+ set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
+ }
+
+ if (di->d_fieldmask & QC_INO_TIMER) {
+ dm->dqb_itime = di->d_ino_timer;
+ check_ilim = 1;
+ set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
+ }
+
+ if (check_blim) {
+ if (!dm->dqb_bsoftlimit ||
+ dm->dqb_curspace + dm->dqb_rsvspace <= dm->dqb_bsoftlimit) {
+ dm->dqb_btime = 0;
+ clear_bit(DQ_BLKS_B, &dquot->dq_flags);
+ } else if (!(di->d_fieldmask & QC_SPC_TIMER))
+ /* Set grace only if user hasn't provided his own... */
+ dm->dqb_btime = ktime_get_real_seconds() + dqi->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->d_fieldmask & QC_INO_TIMER))
+ /* Set grace only if user hasn't provided his own... */
+ dm->dqb_itime = ktime_get_real_seconds() + dqi->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(&dquot->dq_dqb_lock);
+ mark_dquot_dirty(dquot);
+
+ return 0;
+}
+
+int dquot_set_dqblk(struct super_block *sb, struct kqid qid,
+ struct qc_dqblk *di)
+{
+ struct dquot *dquot;
+ int rc;
+
+ dquot = dqget(sb, qid);
+ if (IS_ERR(dquot)) {
+ rc = PTR_ERR(dquot);
+ goto out;
+ }
+ rc = do_set_dqblk(dquot, di);
+ dqput(dquot);
+out:
+ return rc;
+}
+EXPORT_SYMBOL(dquot_set_dqblk);
+
+/* Generic routine for getting common part of quota file information */
+int dquot_get_state(struct super_block *sb, struct qc_state *state)
+{
+ struct mem_dqinfo *mi;
+ struct qc_type_state *tstate;
+ struct quota_info *dqopt = sb_dqopt(sb);
+ int type;
+
+ memset(state, 0, sizeof(*state));
+ for (type = 0; type < MAXQUOTAS; type++) {
+ if (!sb_has_quota_active(sb, type))
+ continue;
+ tstate = state->s_state + type;
+ mi = sb_dqopt(sb)->info + type;
+ tstate->flags = QCI_ACCT_ENABLED;
+ spin_lock(&dq_data_lock);
+ if (mi->dqi_flags & DQF_SYS_FILE)
+ tstate->flags |= QCI_SYSFILE;
+ if (mi->dqi_flags & DQF_ROOT_SQUASH)
+ tstate->flags |= QCI_ROOT_SQUASH;
+ if (sb_has_quota_limits_enabled(sb, type))
+ tstate->flags |= QCI_LIMITS_ENFORCED;
+ tstate->spc_timelimit = mi->dqi_bgrace;
+ tstate->ino_timelimit = mi->dqi_igrace;
+ if (dqopt->files[type]) {
+ tstate->ino = dqopt->files[type]->i_ino;
+ tstate->blocks = dqopt->files[type]->i_blocks;
+ }
+ tstate->nextents = 1; /* We don't know... */
+ spin_unlock(&dq_data_lock);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(dquot_get_state);
+
+/* Generic routine for setting common part of quota file information */
+int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii)
+{
+ struct mem_dqinfo *mi;
+
+ if ((ii->i_fieldmask & QC_WARNS_MASK) ||
+ (ii->i_fieldmask & QC_RT_SPC_TIMER))
+ return -EINVAL;
+ if (!sb_has_quota_active(sb, type))
+ return -ESRCH;
+ mi = sb_dqopt(sb)->info + type;
+ if (ii->i_fieldmask & QC_FLAGS) {
+ if ((ii->i_flags & QCI_ROOT_SQUASH &&
+ mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD))
+ return -EINVAL;
+ }
+ spin_lock(&dq_data_lock);
+ if (ii->i_fieldmask & QC_SPC_TIMER)
+ mi->dqi_bgrace = ii->i_spc_timelimit;
+ if (ii->i_fieldmask & QC_INO_TIMER)
+ mi->dqi_igrace = ii->i_ino_timelimit;
+ if (ii->i_fieldmask & QC_FLAGS) {
+ if (ii->i_flags & QCI_ROOT_SQUASH)
+ mi->dqi_flags |= DQF_ROOT_SQUASH;
+ else
+ mi->dqi_flags &= ~DQF_ROOT_SQUASH;
+ }
+ spin_unlock(&dq_data_lock);
+ mark_info_dirty(sb, type);
+ /* Force write to disk */
+ return sb->dq_op->write_info(sb, type);
+}
+EXPORT_SYMBOL(dquot_set_dqinfo);
+
+const struct quotactl_ops dquot_quotactl_sysfile_ops = {
+ .quota_enable = dquot_quota_enable,
+ .quota_disable = dquot_quota_disable,
+ .quota_sync = dquot_quota_sync,
+ .get_state = dquot_get_state,
+ .set_info = dquot_set_dqinfo,
+ .get_dqblk = dquot_get_dqblk,
+ .get_nextdqblk = dquot_get_next_dqblk,
+ .set_dqblk = dquot_set_dqblk
+};
+EXPORT_SYMBOL(dquot_quotactl_sysfile_ops);
+
+static int do_proc_dqstats(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp, loff_t *ppos)
+{
+ unsigned int type = (unsigned long *)table->data - dqstats.stat;
+ s64 value = percpu_counter_sum(&dqstats.counter[type]);
+
+ /* Filter negative values for non-monotonic counters */
+ if (value < 0 && (type == DQST_ALLOC_DQUOTS ||
+ type == DQST_FREE_DQUOTS))
+ value = 0;
+
+ /* Update global table */
+ dqstats.stat[type] = value;
+ return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
+}
+
+static struct ctl_table fs_dqstats_table[] = {
+ {
+ .procname = "lookups",
+ .data = &dqstats.stat[DQST_LOOKUPS],
+ .maxlen = sizeof(unsigned long),
+ .mode = 0444,
+ .proc_handler = do_proc_dqstats,
+ },
+ {
+ .procname = "drops",
+ .data = &dqstats.stat[DQST_DROPS],
+ .maxlen = sizeof(unsigned long),
+ .mode = 0444,
+ .proc_handler = do_proc_dqstats,
+ },
+ {
+ .procname = "reads",
+ .data = &dqstats.stat[DQST_READS],
+ .maxlen = sizeof(unsigned long),
+ .mode = 0444,
+ .proc_handler = do_proc_dqstats,
+ },
+ {
+ .procname = "writes",
+ .data = &dqstats.stat[DQST_WRITES],
+ .maxlen = sizeof(unsigned long),
+ .mode = 0444,
+ .proc_handler = do_proc_dqstats,
+ },
+ {
+ .procname = "cache_hits",
+ .data = &dqstats.stat[DQST_CACHE_HITS],
+ .maxlen = sizeof(unsigned long),
+ .mode = 0444,
+ .proc_handler = do_proc_dqstats,
+ },
+ {
+ .procname = "allocated_dquots",
+ .data = &dqstats.stat[DQST_ALLOC_DQUOTS],
+ .maxlen = sizeof(unsigned long),
+ .mode = 0444,
+ .proc_handler = do_proc_dqstats,
+ },
+ {
+ .procname = "free_dquots",
+ .data = &dqstats.stat[DQST_FREE_DQUOTS],
+ .maxlen = sizeof(unsigned long),
+ .mode = 0444,
+ .proc_handler = do_proc_dqstats,
+ },
+ {
+ .procname = "syncs",
+ .data = &dqstats.stat[DQST_SYNCS],
+ .maxlen = sizeof(unsigned long),
+ .mode = 0444,
+ .proc_handler = do_proc_dqstats,
+ },
+#ifdef CONFIG_PRINT_QUOTA_WARNING
+ {
+ .procname = "warnings",
+ .data = &flag_print_warnings,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+#endif
+ { },
+};
+
+static int __init dquot_init(void)
+{
+ int i, ret;
+ unsigned long nr_hash, order;
+
+ printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
+
+ register_sysctl_init("fs/quota", fs_dqstats_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_KERNEL, order);
+ if (!dquot_hash)
+ panic("Cannot create dquot hash table");
+
+ for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
+ ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL);
+ if (ret)
+ panic("Cannot create dquot stat counters");
+ }
+
+ /* Find power-of-two hlist_heads which can fit into allocation */
+ nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
+ dq_hash_bits = ilog2(nr_hash);
+
+ 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);
+
+ pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld,"
+ " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order));
+
+ if (register_shrinker(&dqcache_shrinker, "dquota-cache"))
+ panic("Cannot register dquot shrinker");
+
+ return 0;
+}
+fs_initcall(dquot_init);