ext4_inline_data_fiemap-should-respect-callers-argument

   1 ext4: ext4_inline_data_fiemap should respect callers argument
   2
   3 From: Dmitry Monakhov <dmonakhov@openvz.org>
   4
   5 Currently ext4_inline_data_fiemap ignores requested arguments (start
   6 and len) which may lead endless loop if start != 0.  Also fix incorrect
   7 extent length determination.
   8
   9 Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
  10 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  11 ---
  12  fs/ext4/ext4.h    |  2 +-
  13  fs/ext4/extents.c |  3 ++-
  14  fs/ext4/inline.c  | 19 +++++++++++++------
  15  3 files changed, 16 insertions(+), 8 deletions(-)
  16
  17 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  18 index e2eba82..29c43e7 100644
  19 --- a/fs/ext4/ext4.h
  20 +++ b/fs/ext4/ext4.h
  21 @@ -2638,7 +2638,7 @@ extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
  22                                         int *retval);
  23  extern int ext4_inline_data_fiemap(struct inode *inode,
  24                                    struct fiemap_extent_info *fieinfo,
  25 -                                  int *has_inline);
  26 +                                  int *has_inline, __u64 start, __u64 len);
  27  extern int ext4_try_to_evict_inline_data(handle_t *handle,
  28                                          struct inode *inode,
  29                                          int needed);
  30 diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
  31 index c3a1fa1..bed4308 100644
  32 --- a/fs/ext4/extents.c
  33 +++ b/fs/ext4/extents.c
  34 @@ -5151,7 +5151,8 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
  35         if (ext4_has_inline_data(inode)) {
  36                 int has_inline = 1;
  37
  38 -               error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline);
  39 +               error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
  40 +                                               start, len);
  41
  42                 if (has_inline)
  43                         return error;
  44 diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
  45 index efdcede..b32d77b 100644
  46 --- a/fs/ext4/inline.c
  47 +++ b/fs/ext4/inline.c
  48 @@ -1808,11 +1808,12 @@ int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
  49
  50  int ext4_inline_data_fiemap(struct inode *inode,
  51                             struct fiemap_extent_info *fieinfo,
  52 -                           int *has_inline)
  53 +                           int *has_inline, __u64 start, __u64 len)
  54  {
  55         __u64 physical = 0;
  56 -       __u64 length;
  57 -       __u32 flags = FIEMAP_EXTENT_DATA_INLINE | FIEMAP_EXTENT_LAST;
  58 +       __u64 inline_len;
  59 +       __u32 flags = FIEMAP_EXTENT_DATA_INLINE | FIEMAP_EXTENT_NOT_ALIGNED |
  60 +               FIEMAP_EXTENT_LAST;
  61         int error = 0;
  62         struct ext4_iloc iloc;
  63
  64 @@ -1821,6 +1822,13 @@ int ext4_inline_data_fiemap(struct inode *inode,
  65                 *has_inline = 0;
  66                 goto out;
  67         }
  68 +       inline_len = min_t(size_t, ext4_get_inline_size(inode),
  69 +                          i_size_read(inode));
  70 +       if (start >= inline_len)
  71 +               goto out;
  72 +       if (start + len < inline_len)
  73 +               inline_len = start + len;
  74 +       inline_len -= start;
  75
  76         error = ext4_get_inode_loc(inode, &iloc);
  77         if (error)
  78 @@ -1829,11 +1837,10 @@ int ext4_inline_data_fiemap(struct inode *inode,
  79         physical = (__u64)iloc.bh->b_blocknr << inode->i_sb->s_blocksize_bits;
  80         physical += (char *)ext4_raw_inode(&iloc) - iloc.bh->b_data;
  81         physical += offsetof(struct ext4_inode, i_block);
  82 -       length = i_size_read(inode);
  83
  84         if (physical)
  85 -               error = fiemap_fill_next_extent(fieinfo, 0, physical,
  86 -                                               length, flags);
  87 +               error = fiemap_fill_next_extent(fieinfo, start, physical,
  88 +                                               inline_len, flags);
  89         brelse(iloc.bh);
  90  out:
  91         up_read(&EXT4_I(inode)->xattr_sem);