From 2f7c68cb55ecb7331f2381deb497c27155f32faf Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 03 Jan 2024 09:43:39 +0000
Subject: [PATCH] update kernel to 5.10.198
---
kernel/fs/quota/dquot.c | 181 ++++++++++++++++++++++++++++++---------------
1 files changed, 121 insertions(+), 60 deletions(-)
diff --git a/kernel/fs/quota/dquot.c b/kernel/fs/quota/dquot.c
index 65f123d..13a9a17 100644
--- a/kernel/fs/quota/dquot.c
+++ b/kernel/fs/quota/dquot.c
@@ -225,12 +225,21 @@
/*
* Dquot List Management:
- * The quota code uses four lists for dquot management: the inuse_list,
- * 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.
+ * 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 will be dropped, the dquot will be
+ * added to releasing_dquots. We'd then queue work item which would call
+ * synchronize_srcu() and after that perform the final cleanup of all the
+ * dquots on the list. Both releasing_dquots and free_dquots use the
+ * dq_free list_head in the dquot struct. When a dquot is removed from
+ * releasing_dquots, a reference count is always subtracted, and if
+ * dq_count == 0 at that point, the dquot will be added to the free_dquots.
*
* 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
@@ -250,6 +259,7 @@
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;
@@ -259,6 +269,9 @@
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)
@@ -307,12 +320,18 @@
dqstats_inc(DQST_FREE_DQUOTS);
}
+static inline void put_releasing_dquots(struct dquot *dquot)
+{
+ list_add_tail(&dquot->dq_free, &releasing_dquots);
+}
+
static inline void remove_free_dquot(struct dquot *dquot)
{
if (list_empty(&dquot->dq_free))
return;
list_del_init(&dquot->dq_free);
- dqstats_dec(DQST_FREE_DQUOTS);
+ if (!atomic_read(&dquot->dq_count))
+ dqstats_dec(DQST_FREE_DQUOTS);
}
static inline void put_inuse(struct dquot *dquot)
@@ -338,6 +357,11 @@
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);
@@ -353,14 +377,14 @@
{
int ret = 1;
- if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
+ 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 (test_bit(DQ_MOD_B, &dquot->dq_flags))
+ if (dquot_dirty(dquot))
return 1;
spin_lock(&dq_list_lock);
@@ -442,7 +466,7 @@
smp_mb__before_atomic();
set_bit(DQ_READ_B, &dquot->dq_flags);
/* Instantiate dquot if needed */
- if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
+ 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])) {
@@ -484,7 +508,7 @@
goto out_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))
+ if (dquot_active(dquot))
ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
else
ret = -EIO;
@@ -549,6 +573,8 @@
struct dquot *dquot, *tmp;
restart:
+ flush_delayed_work("a_release_work);
+
spin_lock(&dq_list_lock);
list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
if (dquot->dq_sb != sb)
@@ -557,7 +583,13 @@
continue;
/* Wait for dquot users */
if (atomic_read(&dquot->dq_count)) {
- dqgrab(dquot);
+ /* dquot in releasing_dquots, flush and retry */
+ if (!list_empty(&dquot->dq_free)) {
+ spin_unlock(&dq_list_lock);
+ goto restart;
+ }
+
+ atomic_inc(&dquot->dq_count);
spin_unlock(&dq_list_lock);
/*
* Once dqput() wakes us up, we know it's time to free
@@ -599,7 +631,7 @@
spin_lock(&dq_list_lock);
list_for_each_entry(dquot, &inuse_list, dq_inuse) {
- if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
+ if (!dquot_active(dquot))
continue;
if (dquot->dq_sb != sb)
continue;
@@ -614,7 +646,7 @@
* outstanding call and recheck the DQ_ACTIVE_B after that.
*/
wait_on_dquot(dquot);
- if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
+ if (dquot_active(dquot)) {
ret = fn(dquot, priv);
if (ret < 0)
goto out;
@@ -629,6 +661,18 @@
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)
@@ -653,23 +697,16 @@
dquot = list_first_entry(&dirty, struct dquot,
dq_dirty);
- WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags));
+ WARN_ON(!dquot_active(dquot));
/* 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 = sb->dq_op->write_dquot(dquot);
- if (err) {
- /*
- * Clear dirty bit anyway to avoid infinite
- * loop here.
- */
- clear_dquot_dirty(dquot);
- if (!ret)
- ret = err;
- }
+ err = dquot_write_dquot(dquot);
+ if (err && !ret)
+ ret = err;
dqput(dquot);
spin_lock(&dq_list_lock);
}
@@ -763,12 +800,53 @@
};
/*
+ * 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);
+
+restart:
+ synchronize_srcu(&dquot_srcu);
+ spin_lock(&dq_list_lock);
+ while (!list_empty(&rls_head)) {
+ dquot = list_first_entry(&rls_head, struct dquot, dq_free);
+ /* Dquot got used again? */
+ if (atomic_read(&dquot->dq_count) > 1) {
+ remove_free_dquot(dquot);
+ atomic_dec(&dquot->dq_count);
+ continue;
+ }
+ 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);
+ atomic_dec(&dquot->dq_count);
+ put_dquot_last(dquot);
+ }
+ spin_unlock(&dq_list_lock);
+}
+
+/*
* Put reference to dquot
*/
void dqput(struct dquot *dquot)
{
- int ret;
-
if (!dquot)
return;
#ifdef CONFIG_QUOTA_DEBUG
@@ -780,7 +858,7 @@
}
#endif
dqstats_inc(DQST_DROPS);
-we_slept:
+
spin_lock(&dq_list_lock);
if (atomic_read(&dquot->dq_count) > 1) {
/* We have more than one user... nothing to do */
@@ -792,35 +870,15 @@
spin_unlock(&dq_list_lock);
return;
}
+
/* Need to release dquot? */
- if (dquot_dirty(dquot)) {
- spin_unlock(&dq_list_lock);
- /* Commit dquot before releasing */
- 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);
- /*
- * We clear dirty bit anyway, so that we avoid
- * infinite loop here
- */
- clear_dquot_dirty(dquot);
- }
- goto we_slept;
- }
- 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 CONFIG_QUOTA_DEBUG
/* sanity check */
BUG_ON(!list_empty(&dquot->dq_free));
#endif
- put_dquot_last(dquot);
+ put_releasing_dquots(dquot);
spin_unlock(&dq_list_lock);
+ queue_delayed_work(system_unbound_wq, "a_release_work, 1);
}
EXPORT_SYMBOL(dqput);
@@ -910,7 +968,7 @@
* already finished or it will be canceled due to dq_count > 1 test */
wait_on_dquot(dquot);
/* Read the dquot / allocate space in quota file */
- if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
+ if (!dquot_active(dquot)) {
int err;
err = sb->dq_op->acquire_dquot(dquot);
@@ -1427,7 +1485,7 @@
return QUOTA_NL_NOWARN;
}
-static int dquot_active(const struct inode *inode)
+static int inode_quota_active(const struct inode *inode)
{
struct super_block *sb = inode->i_sb;
@@ -1450,7 +1508,7 @@
qsize_t rsv;
int ret = 0;
- if (!dquot_active(inode))
+ if (!inode_quota_active(inode))
return 0;
dquots = i_dquot(inode);
@@ -1558,7 +1616,7 @@
struct dquot **dquots;
int i;
- if (!dquot_active(inode))
+ if (!inode_quota_active(inode))
return false;
dquots = i_dquot(inode);
@@ -1669,7 +1727,7 @@
int reserve = flags & DQUOT_SPACE_RESERVE;
struct dquot **dquots;
- if (!dquot_active(inode)) {
+ if (!inode_quota_active(inode)) {
if (reserve) {
spin_lock(&inode->i_lock);
*inode_reserved_space(inode) += number;
@@ -1739,7 +1797,7 @@
struct dquot_warn warn[MAXQUOTAS];
struct dquot * const *dquots;
- if (!dquot_active(inode))
+ if (!inode_quota_active(inode))
return 0;
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
warn[cnt].w_type = QUOTA_NL_NOWARN;
@@ -1782,7 +1840,7 @@
struct dquot **dquots;
int cnt, index;
- if (!dquot_active(inode)) {
+ if (!inode_quota_active(inode)) {
spin_lock(&inode->i_lock);
*inode_reserved_space(inode) -= number;
__inode_add_bytes(inode, number);
@@ -1824,7 +1882,7 @@
struct dquot **dquots;
int cnt, index;
- if (!dquot_active(inode)) {
+ if (!inode_quota_active(inode)) {
spin_lock(&inode->i_lock);
*inode_reserved_space(inode) += number;
__inode_sub_bytes(inode, number);
@@ -1868,7 +1926,7 @@
struct dquot **dquots;
int reserve = flags & DQUOT_SPACE_RESERVE, index;
- if (!dquot_active(inode)) {
+ if (!inode_quota_active(inode)) {
if (reserve) {
spin_lock(&inode->i_lock);
*inode_reserved_space(inode) -= number;
@@ -1923,7 +1981,7 @@
struct dquot * const *dquots;
int index;
- if (!dquot_active(inode))
+ if (!inode_quota_active(inode))
return;
dquots = i_dquot(inode);
@@ -2094,7 +2152,7 @@
struct super_block *sb = inode->i_sb;
int ret;
- if (!dquot_active(inode))
+ if (!inode_quota_active(inode))
return 0;
if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){
@@ -2319,6 +2377,8 @@
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))
@@ -2413,7 +2473,8 @@
error = add_dquot_ref(sb, type);
if (error)
- dquot_disable(sb, type, flags);
+ dquot_disable(sb, type,
+ DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
return error;
out_fmt:
--
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