remove-EXT4_STATE_DIOREAD_LOCK-flag

   1 ext4: remove EXT4_STATE_DIOREAD_LOCK flag
   2
   3 From: Nikolay Borisov <nborisov@suse.com>
   4
   5 Commit 16c54688592c ("ext4: Allow parallel DIO reads") reworked the way
   6 locking happens around parallel dio reads. This resulted in obviating
   7 the need for EXT4_STATE_DIOREAD_LOCK flag and accompanying logic.
   8 Currently this amounts to dead code so let's remove it. No functional
   9 changes
  10
  11 Signed-off-by: Nikolay Borisov <nborisov@suse.com>
  12 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  13 Reviewed-by: Jan Kara <jack@suse.cz>
  14 ---
  15  fs/ext4/ext4.h        | 17 -----------------
  16  fs/ext4/extents.c     | 19 +++++--------------
  17  fs/ext4/inode.c       |  8 --------
  18  fs/ext4/ioctl.c       |  4 ----
  19  fs/ext4/move_extent.c |  4 ----
  20  fs/ext4/super.c       | 12 +++++-------
  21  6 files changed, 10 insertions(+), 54 deletions(-)
  22
  23 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  24 index 3241475a1733..a42e71203e53 100644
  25 --- a/fs/ext4/ext4.h
  26 +++ b/fs/ext4/ext4.h
  27 @@ -1522,8 +1522,6 @@ enum {
  28         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
  29         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
  30         EXT4_STATE_NEWENTRY,            /* File just added to dir */
  31 -       EXT4_STATE_DIOREAD_LOCK,        /* Disable support for dio read
  32 -                                          nolocking */
  33         EXT4_STATE_MAY_INLINE_DATA,     /* may have in-inode data */
  34         EXT4_STATE_EXT_PRECACHED,       /* extents have been precached */
  35         EXT4_STATE_LUSTRE_EA_INODE,     /* Lustre-style ea_inode */
  36 @@ -3181,21 +3179,6 @@ static inline void set_bitmap_uptodate(struct buffer_head *bh)
  37         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
  38  }
  39
  40 -/*
  41 - * Disable DIO read nolock optimization, so new dioreaders will be forced
  42 - * to grab i_mutex
  43 - */
  44 -static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
  45 -{
  46 -       ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
  47 -       smp_mb();
  48 -}
  49 -static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
  50 -{
  51 -       smp_mb();
  52 -       ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
  53 -}
  54 -
  55  #define in_range(b, first, len)        ((b) >= (first) && (b) <= (first) + (len) - 1)
  56
  57  /* For ioend & aio unwritten conversion wait queues */
  58 diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
  59 index 054416e9d827..837f0a6357c7 100644
  60 --- a/fs/ext4/extents.c
  61 +++ b/fs/ext4/extents.c
  62 @@ -4796,7 +4796,6 @@ static long ext4_zero_range(struct file *file, loff_t offset,
  63                 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
  64
  65         /* Wait all existing dio workers, newcomers will block on i_mutex */
  66 -       ext4_inode_block_unlocked_dio(inode);
  67         inode_dio_wait(inode);
  68
  69         /* Preallocate the range including the unaligned edges */
  70 @@ -4807,7 +4806,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
  71                                  round_down(offset, 1 << blkbits)) >> blkbits,
  72                                 new_size, flags);
  73                 if (ret)
  74 -                       goto out_dio;
  75 +                       goto out_mutex;
  76
  77         }
  78
  79 @@ -4824,7 +4823,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
  80                 ret = ext4_update_disksize_before_punch(inode, offset, len);
  81                 if (ret) {
  82                         up_write(&EXT4_I(inode)->i_mmap_sem);
  83 -                       goto out_dio;
  84 +                       goto out_mutex;
  85                 }
  86                 /* Now release the pages and zero block aligned part of pages */
  87                 truncate_pagecache_range(inode, start, end - 1);
  88 @@ -4834,10 +4833,10 @@ static long ext4_zero_range(struct file *file, loff_t offset,
  89                                              flags);
  90                 up_write(&EXT4_I(inode)->i_mmap_sem);
  91                 if (ret)
  92 -                       goto out_dio;
  93 +                       goto out_mutex;
  94         }
  95         if (!partial_begin && !partial_end)
  96 -               goto out_dio;
  97 +               goto out_mutex;
  98
  99         /*
 100          * In worst case we have to writeout two nonadjacent unwritten
 101 @@ -4850,7 +4849,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 102         if (IS_ERR(handle)) {
 103                 ret = PTR_ERR(handle);
 104                 ext4_std_error(inode->i_sb, ret);
 105 -               goto out_dio;
 106 +               goto out_mutex;
 107         }
 108
 109         inode->i_mtime = inode->i_ctime = current_time(inode);
 110 @@ -4875,8 +4874,6 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 111                 ext4_handle_sync(handle);
 112
 113         ext4_journal_stop(handle);
 114 -out_dio:
 115 -       ext4_inode_resume_unlocked_dio(inode);
 116  out_mutex:
 117         inode_unlock(inode);
 118         return ret;
 119 @@ -4964,11 +4961,9 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 120         }
 121
 122         /* Wait all existing dio workers, newcomers will block on i_mutex */
 123 -       ext4_inode_block_unlocked_dio(inode);
 124         inode_dio_wait(inode);
 125
 126         ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags);
 127 -       ext4_inode_resume_unlocked_dio(inode);
 128         if (ret)
 129                 goto out;
 130
 131 @@ -5485,7 +5480,6 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
 132         }
 133
 134         /* Wait for existing dio to complete */
 135 -       ext4_inode_block_unlocked_dio(inode);
 136         inode_dio_wait(inode);
 137
 138         /*
 139 @@ -5562,7 +5556,6 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
 140         ext4_journal_stop(handle);
 141  out_mmap:
 142         up_write(&EXT4_I(inode)->i_mmap_sem);
 143 -       ext4_inode_resume_unlocked_dio(inode);
 144  out_mutex:
 145         inode_unlock(inode);
 146         return ret;
 147 @@ -5635,7 +5628,6 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
 148         }
 149
 150         /* Wait for existing dio to complete */
 151 -       ext4_inode_block_unlocked_dio(inode);
 152         inode_dio_wait(inode);
 153
 154         /*
 155 @@ -5737,7 +5729,6 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
 156         ext4_journal_stop(handle);
 157  out_mmap:
 158         up_write(&EXT4_I(inode)->i_mmap_sem);
 159 -       ext4_inode_resume_unlocked_dio(inode);
 160  out_mutex:
 161         inode_unlock(inode);
 162         return ret;
 163 diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
 164 index c94780075b04..7d285e79fd9f 100644
 165 --- a/fs/ext4/inode.c
 166 +++ b/fs/ext4/inode.c
 167 @@ -4251,7 +4251,6 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
 168         }
 169
 170         /* Wait all existing dio workers, newcomers will block on i_mutex */
 171 -       ext4_inode_block_unlocked_dio(inode);
 172         inode_dio_wait(inode);
 173
 174         /*
 175 @@ -4324,7 +4323,6 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
 176         ext4_journal_stop(handle);
 177  out_dio:
 178         up_write(&EXT4_I(inode)->i_mmap_sem);
 179 -       ext4_inode_resume_unlocked_dio(inode);
 180  out_mutex:
 181         inode_unlock(inode);
 182         return ret;
 183 @@ -5506,9 +5504,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 184                  */
 185                 if (orphan) {
 186                         if (!ext4_should_journal_data(inode)) {
 187 -                               ext4_inode_block_unlocked_dio(inode);
 188                                 inode_dio_wait(inode);
 189 -                               ext4_inode_resume_unlocked_dio(inode);
 190                         } else
 191                                 ext4_wait_for_tail_page_commit(inode);
 192                 }
 193 @@ -5999,7 +5995,6 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
 194                 return -EROFS;
 195
 196         /* Wait for all existing dio workers */
 197 -       ext4_inode_block_unlocked_dio(inode);
 198         inode_dio_wait(inode);
 199
 200         /*
 201 @@ -6015,7 +6010,6 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
 202                 err = filemap_write_and_wait(inode->i_mapping);
 203                 if (err < 0) {
 204                         up_write(&EXT4_I(inode)->i_mmap_sem);
 205 -                       ext4_inode_resume_unlocked_dio(inode);
 206                         return err;
 207                 }
 208         }
 209 @@ -6038,7 +6032,6 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
 210                 if (err < 0) {
 211                         jbd2_journal_unlock_updates(journal);
 212                         percpu_up_write(&sbi->s_journal_flag_rwsem);
 213 -                       ext4_inode_resume_unlocked_dio(inode);
 214                         return err;
 215                 }
 216                 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
 217 @@ -6050,7 +6043,6 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
 218
 219         if (val)
 220                 up_write(&EXT4_I(inode)->i_mmap_sem);
 221 -       ext4_inode_resume_unlocked_dio(inode);
 222
 223         /* Finally we can mark the inode as dirty. */
 224
 225 diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
 226 index 7e99ad02f1ba..3644e31ba347 100644
 227 --- a/fs/ext4/ioctl.c
 228 +++ b/fs/ext4/ioctl.c
 229 @@ -124,8 +124,6 @@ static long swap_inode_boot_loader(struct super_block *sb,
 230         truncate_inode_pages(&inode_bl->i_data, 0);
 231
 232         /* Wait for all existing dio workers */
 233 -       ext4_inode_block_unlocked_dio(inode);
 234 -       ext4_inode_block_unlocked_dio(inode_bl);
 235         inode_dio_wait(inode);
 236         inode_dio_wait(inode_bl);
 237
 238 @@ -186,8 +184,6 @@ static long swap_inode_boot_loader(struct super_block *sb,
 239         ext4_double_up_write_data_sem(inode, inode_bl);
 240
 241  journal_err_out:
 242 -       ext4_inode_resume_unlocked_dio(inode);
 243 -       ext4_inode_resume_unlocked_dio(inode_bl);
 244         unlock_two_nondirectories(inode, inode_bl);
 245         iput(inode_bl);
 246         return err;
 247 diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
 248 index b96e4bd3b3ec..8e17efdcbf11 100644
 249 --- a/fs/ext4/move_extent.c
 250 +++ b/fs/ext4/move_extent.c
 251 @@ -601,8 +601,6 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,
 252         lock_two_nondirectories(orig_inode, donor_inode);
 253
 254         /* Wait for all existing dio workers */
 255 -       ext4_inode_block_unlocked_dio(orig_inode);
 256 -       ext4_inode_block_unlocked_dio(donor_inode);
 257         inode_dio_wait(orig_inode);
 258         inode_dio_wait(donor_inode);
 259
 260 @@ -693,8 +691,6 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,
 261         ext4_ext_drop_refs(path);
 262         kfree(path);
 263         ext4_double_up_write_data_sem(orig_inode, donor_inode);
 264 -       ext4_inode_resume_unlocked_dio(orig_inode);
 265 -       ext4_inode_resume_unlocked_dio(donor_inode);
 266         unlock_two_nondirectories(orig_inode, donor_inode);
 267
 268         return ret;
 269 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
 270 index 39bf464c35f1..8781f8afbe50 100644
 271 --- a/fs/ext4/super.c
 272 +++ b/fs/ext4/super.c
 273 @@ -101,15 +101,13 @@ static struct inode *ext4_get_journal_inode(struct super_block *sb,
 274   *   i_data_sem (rw)
 275   *
 276   * truncate:
 277 - * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 278 - *   i_mmap_rwsem (w) -> page lock
 279 - * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 280 - *   transaction start -> i_data_sem (rw)
 281 + * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
 282 + * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
 283 + *   i_data_sem (rw)
 284   *
 285   * direct IO:
 286 - * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 287 - * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 288 - *   transaction start -> i_data_sem (rw)
 289 + * sb_start_write -> i_mutex -> mmap_sem
 290 + * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
 291   *
 292   * writepages:
 293   * transaction start -> page lock(s) -> i_data_sem (rw)
 294 --
 295 2.7.4
 296
 297