releases/6.1.83/quota-fix-rcu-annotations-of-inode-dquot-pointers.patch

   1 From 40287aff4b5937a5c23db1e30b8522081d98e327 Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Tue, 6 Feb 2024 15:32:09 +0100
   4 Subject: quota: Fix rcu annotations of inode dquot pointers
   5
   6 From: Jan Kara <jack@suse.cz>
   7
   8 [ Upstream commit 179b8c97ebf63429589f5afeba59a181fe70603e ]
   9
  10 Dquot pointers in i_dquot array in the inode are protected by
  11 dquot_srcu. Annotate the array pointers with __rcu, perform the locked
  12 dereferences with srcu_dereference_check() instead of plain reads, and
  13 set the array elements with rcu_assign_pointer().
  14
  15 Fixes: b9ba6f94b238 ("quota: remove dqptr_sem")
  16 Reported-by: kernel test robot <lkp@intel.com>
  17 Closes: https://lore.kernel.org/oe-kbuild-all/202402061900.rTuYDlo6-lkp@intel.com/
  18 Signed-off-by: Jan Kara <jack@suse.cz>
  19 Signed-off-by: Sasha Levin <sashal@kernel.org>
  20 ---
  21  fs/quota/dquot.c | 66 ++++++++++++++++++++++++++++--------------------
  22  1 file changed, 39 insertions(+), 27 deletions(-)
  23
  24 diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
  25 index 44c4da364c994..b67557647d61f 100644
  26 --- a/fs/quota/dquot.c
  27 +++ b/fs/quota/dquot.c
  28 @@ -399,7 +399,7 @@ int dquot_mark_dquot_dirty(struct dquot *dquot)
  29  EXPORT_SYMBOL(dquot_mark_dquot_dirty);
  30
  31  /* Dirtify all the dquots - this can block when journalling */
  32 -static inline int mark_all_dquot_dirty(struct dquot * const *dquots)
  33 +static inline int mark_all_dquot_dirty(struct dquot __rcu * const *dquots)
  34  {
  35         int ret, err, cnt;
  36         struct dquot *dquot;
  37 @@ -1006,14 +1006,15 @@ struct dquot *dqget(struct super_block *sb, struct kqid qid)
  38  }
  39  EXPORT_SYMBOL(dqget);
  40
  41 -static inline struct dquot **i_dquot(struct inode *inode)
  42 +static inline struct dquot __rcu **i_dquot(struct inode *inode)
  43  {
  44 -       return inode->i_sb->s_op->get_dquots(inode);
  45 +       /* Force __rcu for now until filesystems are fixed */
  46 +       return (struct dquot __rcu **)inode->i_sb->s_op->get_dquots(inode);
  47  }
  48
  49  static int dqinit_needed(struct inode *inode, int type)
  50  {
  51 -       struct dquot * const *dquots;
  52 +       struct dquot __rcu * const *dquots;
  53         int cnt;
  54
  55         if (IS_NOQUOTA(inode))
  56 @@ -1103,14 +1104,16 @@ static void remove_dquot_ref(struct super_block *sb, int type)
  57                  */
  58                 spin_lock(&dq_data_lock);
  59                 if (!IS_NOQUOTA(inode)) {
  60 -                       struct dquot **dquots = i_dquot(inode);
  61 -                       struct dquot *dquot = dquots[type];
  62 +                       struct dquot __rcu **dquots = i_dquot(inode);
  63 +                       struct dquot *dquot = srcu_dereference_check(
  64 +                               dquots[type], &dquot_srcu,
  65 +                               lockdep_is_held(&dq_data_lock));
  66
  67  #ifdef CONFIG_QUOTA_DEBUG
  68                         if (unlikely(inode_get_rsv_space(inode) > 0))
  69                                 reserved = 1;
  70  #endif
  71 -                       dquots[type] = NULL;
  72 +                       rcu_assign_pointer(dquots[type], NULL);
  73                         if (dquot)
  74                                 dqput(dquot);
  75                 }
  76 @@ -1463,7 +1466,8 @@ static int inode_quota_active(const struct inode *inode)
  77  static int __dquot_initialize(struct inode *inode, int type)
  78  {
  79         int cnt, init_needed = 0;
  80 -       struct dquot **dquots, *got[MAXQUOTAS] = {};
  81 +       struct dquot __rcu **dquots;
  82 +       struct dquot *got[MAXQUOTAS] = {};
  83         struct super_block *sb = inode->i_sb;
  84         qsize_t rsv;
  85         int ret = 0;
  86 @@ -1538,7 +1542,7 @@ static int __dquot_initialize(struct inode *inode, int type)
  87                 if (!got[cnt])
  88                         continue;
  89                 if (!dquots[cnt]) {
  90 -                       dquots[cnt] = got[cnt];
  91 +                       rcu_assign_pointer(dquots[cnt], got[cnt]);
  92                         got[cnt] = NULL;
  93                         /*
  94                          * Make quota reservation system happy if someone
  95 @@ -1546,12 +1550,16 @@ static int __dquot_initialize(struct inode *inode, int type)
  96                          */
  97                         rsv = inode_get_rsv_space(inode);
  98                         if (unlikely(rsv)) {
  99 +                               struct dquot *dquot = srcu_dereference_check(
 100 +                                       dquots[cnt], &dquot_srcu,
 101 +                                       lockdep_is_held(&dq_data_lock));
 102 +
 103                                 spin_lock(&inode->i_lock);
 104                                 /* Get reservation again under proper lock */
 105                                 rsv = __inode_get_rsv_space(inode);
 106 -                               spin_lock(&dquots[cnt]->dq_dqb_lock);
 107 -                               dquots[cnt]->dq_dqb.dqb_rsvspace += rsv;
 108 -                               spin_unlock(&dquots[cnt]->dq_dqb_lock);
 109 +                               spin_lock(&dquot->dq_dqb_lock);
 110 +                               dquot->dq_dqb.dqb_rsvspace += rsv;
 111 +                               spin_unlock(&dquot->dq_dqb_lock);
 112                                 spin_unlock(&inode->i_lock);
 113                         }
 114                 }
 115 @@ -1573,7 +1581,7 @@ EXPORT_SYMBOL(dquot_initialize);
 116
 117  bool dquot_initialize_needed(struct inode *inode)
 118  {
 119 -       struct dquot **dquots;
 120 +       struct dquot __rcu **dquots;
 121         int i;
 122
 123         if (!inode_quota_active(inode))
 124 @@ -1598,13 +1606,14 @@ EXPORT_SYMBOL(dquot_initialize_needed);
 125  static void __dquot_drop(struct inode *inode)
 126  {
 127         int cnt;
 128 -       struct dquot **dquots = i_dquot(inode);
 129 +       struct dquot __rcu **dquots = i_dquot(inode);
 130         struct dquot *put[MAXQUOTAS];
 131
 132         spin_lock(&dq_data_lock);
 133         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
 134 -               put[cnt] = dquots[cnt];
 135 -               dquots[cnt] = NULL;
 136 +               put[cnt] = srcu_dereference_check(dquots[cnt], &dquot_srcu,
 137 +                                       lockdep_is_held(&dq_data_lock));
 138 +               rcu_assign_pointer(dquots[cnt], NULL);
 139         }
 140         spin_unlock(&dq_data_lock);
 141         dqput_all(put);
 142 @@ -1612,7 +1621,7 @@ static void __dquot_drop(struct inode *inode)
 143
 144  void dquot_drop(struct inode *inode)
 145  {
 146 -       struct dquot * const *dquots;
 147 +       struct dquot __rcu * const *dquots;
 148         int cnt;
 149
 150         if (IS_NOQUOTA(inode))
 151 @@ -1685,7 +1694,7 @@ int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
 152         int cnt, ret = 0, index;
 153         struct dquot_warn warn[MAXQUOTAS];
 154         int reserve = flags & DQUOT_SPACE_RESERVE;
 155 -       struct dquot **dquots;
 156 +       struct dquot __rcu **dquots;
 157         struct dquot *dquot;
 158
 159         if (!inode_quota_active(inode)) {
 160 @@ -1755,7 +1764,7 @@ int dquot_alloc_inode(struct inode *inode)
 161  {
 162         int cnt, ret = 0, index;
 163         struct dquot_warn warn[MAXQUOTAS];
 164 -       struct dquot * const *dquots;
 165 +       struct dquot __rcu * const *dquots;
 166         struct dquot *dquot;
 167
 168         if (!inode_quota_active(inode))
 169 @@ -1800,7 +1809,7 @@ EXPORT_SYMBOL(dquot_alloc_inode);
 170   */
 171  int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
 172  {
 173 -       struct dquot **dquots;
 174 +       struct dquot __rcu **dquots;
 175         struct dquot *dquot;
 176         int cnt, index;
 177
 178 @@ -1842,7 +1851,7 @@ EXPORT_SYMBOL(dquot_claim_space_nodirty);
 179   */
 180  void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number)
 181  {
 182 -       struct dquot **dquots;
 183 +       struct dquot __rcu **dquots;
 184         struct dquot *dquot;
 185         int cnt, index;
 186
 187 @@ -1886,7 +1895,7 @@ void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
 188  {
 189         unsigned int cnt;
 190         struct dquot_warn warn[MAXQUOTAS];
 191 -       struct dquot **dquots;
 192 +       struct dquot __rcu **dquots;
 193         struct dquot *dquot;
 194         int reserve = flags & DQUOT_SPACE_RESERVE, index;
 195
 196 @@ -1943,7 +1952,7 @@ void dquot_free_inode(struct inode *inode)
 197  {
 198         unsigned int cnt;
 199         struct dquot_warn warn[MAXQUOTAS];
 200 -       struct dquot * const *dquots;
 201 +       struct dquot __rcu * const *dquots;
 202         struct dquot *dquot;
 203         int index;
 204
 205 @@ -1990,6 +1999,7 @@ int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
 206         qsize_t cur_space;
 207         qsize_t rsv_space = 0;
 208         qsize_t inode_usage = 1;
 209 +       struct dquot __rcu **dquots;
 210         struct dquot *transfer_from[MAXQUOTAS] = {};
 211         int cnt, index, ret = 0;
 212         char is_valid[MAXQUOTAS] = {};
 213 @@ -2022,6 +2032,7 @@ int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
 214         }
 215         cur_space = __inode_get_bytes(inode);
 216         rsv_space = __inode_get_rsv_space(inode);
 217 +       dquots = i_dquot(inode);
 218         /*
 219          * Build the transfer_from list, check limits, and update usage in
 220          * the target structures.
 221 @@ -2036,7 +2047,8 @@ int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
 222                 if (!sb_has_quota_active(inode->i_sb, cnt))
 223                         continue;
 224                 is_valid[cnt] = 1;
 225 -               transfer_from[cnt] = i_dquot(inode)[cnt];
 226 +               transfer_from[cnt] = srcu_dereference_check(dquots[cnt],
 227 +                               &dquot_srcu, lockdep_is_held(&dq_data_lock));
 228                 ret = dquot_add_inodes(transfer_to[cnt], inode_usage,
 229                                        &warn_to[cnt]);
 230                 if (ret)
 231 @@ -2075,7 +2087,7 @@ int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
 232                                                   rsv_space);
 233                         spin_unlock(&transfer_from[cnt]->dq_dqb_lock);
 234                 }
 235 -               i_dquot(inode)[cnt] = transfer_to[cnt];
 236 +               rcu_assign_pointer(dquots[cnt], transfer_to[cnt]);
 237         }
 238         spin_unlock(&inode->i_lock);
 239         spin_unlock(&dq_data_lock);
 240 @@ -2086,8 +2098,8 @@ int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
 241          * mark_all_dquot_dirty().
 242          */
 243         index = srcu_read_lock(&dquot_srcu);
 244 -       mark_all_dquot_dirty(transfer_from);
 245 -       mark_all_dquot_dirty(transfer_to);
 246 +       mark_all_dquot_dirty((struct dquot __rcu **)transfer_from);
 247 +       mark_all_dquot_dirty((struct dquot __rcu **)transfer_to);
 248         srcu_read_unlock(&dquot_srcu, index);
 249
 250         flush_warnings(warn_to);
 251 --
 252 2.43.0
 253