add-iomap-support-for-inline-data

   1 ext4: Add iomap support for inline data
   2
   3 From: Andreas Gruenbacher <agruenba@redhat.com>
   4
   5 Report inline data as a IOMAP_F_DATA_INLINE mapping.  This allows to use
   6 iomap_seek_hole and iomap_seek_data in ext4_llseek and makes switching
   7 to iomap_fiemap in ext4_fiemap easier.
   8
   9 Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
  10 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  11 Reviewed-by: Jan Kara <jack@suse.cz>
  12 ---
  13  fs/ext4/ext4.h   |  4 ++++
  14  fs/ext4/inline.c | 33 +++++++++++++++++++++++++++++++++
  15  fs/ext4/inode.c  | 16 ++++++++++++++--
  16  3 files changed, 51 insertions(+), 2 deletions(-)
  17
  18 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  19 index e2abe01c8c6b..ae3e4a25821a 100644
  20 --- a/fs/ext4/ext4.h
  21 +++ b/fs/ext4/ext4.h
  22 @@ -3048,6 +3048,10 @@ extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
  23  extern int ext4_inline_data_fiemap(struct inode *inode,
  24                                    struct fiemap_extent_info *fieinfo,
  25                                    int *has_inline, __u64 start, __u64 len);
  26 +
  27 +struct iomap;
  28 +extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
  29 +
  30  extern int ext4_try_to_evict_inline_data(handle_t *handle,
  31                                          struct inode *inode,
  32                                          int needed);
  33 diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
  34 index 28c5c3abddb3..f0bbc8cb6555 100644
  35 --- a/fs/ext4/inline.c
  36 +++ b/fs/ext4/inline.c
  37 @@ -12,6 +12,7 @@
  38   * GNU General Public License for more details.
  39   */
  40
  41 +#include <linux/iomap.h>
  42  #include <linux/fiemap.h>
  43
  44  #include "ext4_jbd2.h"
  45 @@ -1827,6 +1828,38 @@ int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
  46         return ret;
  47  }
  48
  49 +int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap)
  50 +{
  51 +       __u64 addr;
  52 +       int error = -EAGAIN;
  53 +       struct ext4_iloc iloc;
  54 +
  55 +       down_read(&EXT4_I(inode)->xattr_sem);
  56 +       if (!ext4_has_inline_data(inode))
  57 +               goto out;
  58 +
  59 +       error = ext4_get_inode_loc(inode, &iloc);
  60 +       if (error)
  61 +               goto out;
  62 +
  63 +       addr = (__u64)iloc.bh->b_blocknr << inode->i_sb->s_blocksize_bits;
  64 +       addr += (char *)ext4_raw_inode(&iloc) - iloc.bh->b_data;
  65 +       addr += offsetof(struct ext4_inode, i_block);
  66 +
  67 +       brelse(iloc.bh);
  68 +
  69 +       iomap->addr = addr;
  70 +       iomap->offset = 0;
  71 +       iomap->length = min_t(loff_t, ext4_get_inline_size(inode),
  72 +                             i_size_read(inode));
  73 +       iomap->type = 0;
  74 +       iomap->flags = IOMAP_F_DATA_INLINE;
  75 +
  76 +out:
  77 +       up_read(&EXT4_I(inode)->xattr_sem);
  78 +       return error;
  79 +}
  80 +
  81  int ext4_inline_data_fiemap(struct inode *inode,
  82                             struct fiemap_extent_info *fieinfo,
  83                             int *has_inline, __u64 start, __u64 len)
  84 diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
  85 index d9e633c12aae..7755f41bdfc3 100644
  86 --- a/fs/ext4/inode.c
  87 +++ b/fs/ext4/inode.c
  88 @@ -3404,8 +3404,20 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
  89         struct ext4_map_blocks map;
  90         int ret;
  91
  92 -       if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
  93 -               return -ERANGE;
  94 +
  95 +       if (flags & IOMAP_REPORT) {
  96 +               if (ext4_has_inline_data(inode)) {
  97 +                       ret = ext4_inline_data_iomap(inode, iomap);
  98 +                       if (ret != -EAGAIN) {
  99 +                               if (ret == 0 && offset >= iomap->length)
 100 +                                       ret = -ENOENT;
 101 +                               return ret;
 102 +                       }
 103 +               }
 104 +       } else {
 105 +               if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
 106 +                       return -ERANGE;
 107 +       }
 108
 109         map.m_lblk = first_block;
 110         map.m_len = last_block - first_block + 1;
 111 --
 112 2.13.3
 113
 114