let-S_DAX-set-only-if-DAX-is-really-supported

   1 ext4: only set S_DAX if DAX is really supported
   2
   3 From: Jan Kara <jack@suse.cz>
   4
   5 Currently we have S_DAX set inode->i_flags for a regular file whenever
   6 ext4 is mounted with dax mount option. However in some cases we cannot
   7 really do DAX - e.g. when inode is marked to use data journalling, when
   8 inode data is being encrypted, or when inode is stored inline. Make sure
   9 S_DAX flag is appropriately set/cleared in these cases.
  10
  11 Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
  12 Signed-off-by: Jan Kara <jack@suse.cz>
  13 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  14 ---
  15  fs/ext4/inline.c | 10 ++++++++++
  16  fs/ext4/inode.c  |  9 ++++++++-
  17  fs/ext4/super.c  |  6 ++++++
  18  3 files changed, 24 insertions(+), 1 deletion(-)
  19
  20 diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
  21 index f74d5ee2cdec..c29678965c3c 100644
  22 --- a/fs/ext4/inline.c
  23 +++ b/fs/ext4/inline.c
  24 @@ -299,6 +299,11 @@ static int ext4_create_inline_data(handle_t *handle,
  25         EXT4_I(inode)->i_inline_size = len + EXT4_MIN_INLINE_DATA_SIZE;
  26         ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
  27         ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA);
  28 +       /*
  29 +        * Propagate changes to inode->i_flags as well - e.g. S_DAX may
  30 +        * get cleared
  31 +        */
  32 +       ext4_set_inode_flags(inode);
  33         get_bh(is.iloc.bh);
  34         error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
  35
  36 @@ -442,6 +447,11 @@ static int ext4_destroy_inline_data_nolock(handle_t *handle,
  37                 }
  38         }
  39         ext4_clear_inode_flag(inode, EXT4_INODE_INLINE_DATA);
  40 +       /*
  41 +        * Propagate changes to inode->i_flags as well - e.g. S_DAX may
  42 +        * get set.
  43 +        */
  44 +       ext4_set_inode_flags(inode);
  45
  46         get_bh(is.iloc.bh);
  47         error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
  48 diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
  49 index 3d58b2b477e8..5337828c68a7 100644
  50 --- a/fs/ext4/inode.c
  51 +++ b/fs/ext4/inode.c
  52 @@ -4355,7 +4355,9 @@ void ext4_set_inode_flags(struct inode *inode)
  53                 new_fl |= S_NOATIME;
  54         if (flags & EXT4_DIRSYNC_FL)
  55                 new_fl |= S_DIRSYNC;
  56 -       if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode))
  57 +       if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode) &&
  58 +           !ext4_should_journal_data(inode) && !ext4_has_inline_data(inode) &&
  59 +           !ext4_encrypted_inode(inode))
  60                 new_fl |= S_DAX;
  61         inode_set_flags(inode, new_fl,
  62                         S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX);
  63 @@ -5623,6 +5625,11 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
  64                 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
  65         }
  66         ext4_set_aops(inode);
  67 +       /*
  68 +        * Update inode->i_flags after EXT4_INODE_JOURNAL_DATA was updated.
  69 +        * E.g. S_DAX may get cleared / set.
  70 +        */
  71 +       ext4_set_inode_flags(inode);
  72
  73         jbd2_journal_unlock_updates(journal);
  74         percpu_up_write(&sbi->s_journal_flag_rwsem);
  75 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
  76 index 20da99da0a34..d5b94cc6a74e 100644
  77 --- a/fs/ext4/super.c
  78 +++ b/fs/ext4/super.c
  79 @@ -1126,6 +1126,10 @@ static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
  80                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
  81                         ext4_clear_inode_state(inode,
  82                                         EXT4_STATE_MAY_INLINE_DATA);
  83 +                       /*
  84 +                        * Update inode->i_flags - e.g. S_DAX may get disabled
  85 +                        */
  86 +                       ext4_set_inode_flags(inode);
  87                 }
  88                 return res;
  89         }
  90 @@ -1140,6 +1144,8 @@ static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
  91                         len, 0);
  92         if (!res) {
  93                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
  94 +               /* Update inode->i_flags - e.g. S_DAX may get disabled */
  95 +               ext4_set_inode_flags(inode);
  96                 res = ext4_mark_inode_dirty(handle, inode);
  97                 if (res)
  98                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
  99 --
 100 2.6.6
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