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| author | Gero Schumacher <Gero.Schumacher@peiker-cee.de> | 2019-02-26 15:45:22 +0000 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2019-04-09 20:04:03 -0400 |
| commit | 1c48fda3e5a88159130b4d4805fbdf367212afab (patch) | |
| tree | 4a088301bce63febd6a4bea46fe3c6541d5f144e /fs | |
| parent | ef79284e7a6ba141b56478f8ed1456ef5c27ae47 (diff) | |
fs: ext4: Problem with ext4load and sparse files
Hi,
when I try to load a sparse file via ext4load, I am getting the error message
'invalid extent'
After a deeper look in the code, it seems to be an issue in the function ext4fs_get_extent_block in fs/ext4/ext4_common.c:
The file starts with 1k of zeros. The blocksize is 1024. So the first extend block contains the following information:
eh_entries: 1
eh_depth: 1
ei_block 1
When the upper layer (ext4fs_read_file) asks for fileblock 0, we are running in the 'invalid extent' error message.
For me it seems, that the code is not prepared for handling a sparse block at the beginning of the file. The following change, solved my problem:
I am really not an expert in ext4 filesystems. Can somebody please have a look at this issue and give me a feedback, if I am totally wrong or not?
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/ext4_common.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index 59ad6c8f8c1..feffbfa9a9e 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -1547,8 +1547,12 @@ static struct ext4_extent_header *ext4fs_get_extent_block break; } while (fileblock >= le32_to_cpu(index[i].ei_block)); - if (--i < 0) - return NULL; + /* + * If first logical block number is higher than requested fileblock, + * it is a sparse file. This is handled on upper layer. + */ + if (i > 0) + i--; block = le16_to_cpu(index[i].ei_leaf_hi); block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo); |