[PATCH 1/1] fs/erofs: silence erofs_probe()

[Heinrich Schuchardt]

On 7/31/22 20:41, Simon Glass wrote:
> On Sun, 31 Jul 2022 at 03:10, Heinrich Schuchardt
> <heinrich.schuchardt at canonical.com> wrote:
>>
>> fs_set_blk_dev() probes all file-systems until it finds one that matches
>> the volume. We do not expect any console output for non-matching
>> file-systems.
>>
>> Convert error messages in erofs_read_superblock() to debug output.
>>
>> Fixes: 830613f8f5bb ("fs/erofs: add erofs filesystem support")
>> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
>> ---
>>   fs/erofs/super.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> Reviewed-by: Simon Glass <sjg at chromium.org>
> 
>>
>> diff --git a/fs/erofs/super.c b/fs/erofs/super.c
>> index 4cca322b9e..095754dc28 100644
>> --- a/fs/erofs/super.c
>> +++ b/fs/erofs/super.c
>> @@ -65,14 +65,14 @@ int erofs_read_superblock(void)
>>
>>          ret = erofs_blk_read(data, 0, 1);
>>          if (ret < 0) {
>> -               erofs_err("cannot read erofs superblock: %d", ret);
>> +               erofs_dbg("cannot read erofs superblock: %d", ret);
>>                  return -EIO;
>>          }
>>          dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET);
>>
>>          ret = -EINVAL;
>>          if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) {
>> -               erofs_err("cannot find valid erofs superblock");
>> +               erofs_dbg("cannot find valid erofs superblock");
>>                  return ret;
>>          }
> 
>> @@ -81,7 +81,7 @@ int erofs_read_superblock(void)
>>          blkszbits = dsb->blkszbits;
>>          /* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */
>>          if (blkszbits != LOG_BLOCK_SIZE) {
>> -               erofs_err("blksize %u isn't supported on this platform",
>> +               erofs_dbg("blksize %u isn't supported on this platform",
>>                            1 << blkszbits);
> 
> Does this message appear in normal scanning, or is it a genuine error?

The erofs driver on Linux only supports LOG_BLOCK_SIZE == 12. So if we 
see this message we don't have a valid erofs file system.

@linux-erofs:

The Linux driver requires EROFS_BLKSIZ == PAGE_SIZE == 4096.
The page size on arm64 can be 4 KiB, 16 KiB, or 64 KiB.
The page size on amd64 can be 4 KiB, 2 MiB or 4 MiB.
Requiring EROFS_BLKSIZ == PAGE_SIZE is obviously a restriction that 
should be lifted.

Best regards

Heinrich

> 
>>                  return ret;
>>          }
> 
>> --
>> 2.36.1
>>