1 .. SPDX-License-Identifier: GPL-2.0
2
3 Inline Data
4 -----------
5
6 The inline data feature was designed to handle
7 data is so tiny that it readily fits inside th
8 (theoretically) reduces disk block consumption
9 file is smaller than 60 bytes, then the data a
10 ``inode.i_block``. If the rest of the file wou
11 attribute space, then it might be found as an
12 “system.data” within the inode body (“ib
13 constrains the amount of extended attributes o
14 If the data size increases beyond i_block + ib
15 is allocated and the contents moved to that bl
16
17 Pending a change to compact the extended attri
18 inline data, one ought to be able to store 160
19 256-byte inode (as of June 2015, when i_extra_
20 that, the limit was 156 bytes due to inefficie
21
22 The inline data feature requires the presence
23 for “system.data”, even if the attribute v
24
25 Inline Directories
26 ~~~~~~~~~~~~~~~~~~
27
28 The first four bytes of i_block are the inode
29 directory. Following that is a 56-byte space f
30 entries; see ``struct ext4_dir_entry``. If the
31 attribute in the inode body, the EA value is a
32 ``struct ext4_dir_entry`` as well. Note that f
33 i_block and EA space are treated as separate d
34 entries cannot span the two.
35
36 Inline directory entries are not checksummed,
37 should protect all inline data contents.
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