Hi Roman,

On Fri, Jun 1, 2018 at 4:25 AM Roman Storozhenko
<romeusmeis...@gmail.com> wrote:
>
> Hello everybody.
>
> I am modifying ufshcd driver:
> https://elixir.bootlin.com/linux/v3.8/source/drivers/scsi/ufs/ufshcd.c
>
> I do a read of a file on ext4 filesystem and want to obtain the file's
> inode. But it seems that there are no structures contatin any
> references to inode at this level of abstraction.

I'm no expert, I'm just answering so you actually have an answer, not
because I have any good knowledge in this area.

This is by design - by the time the data gets to the hardware the
associated file is both irrelevant and unobtainable: the read or write
might be metadata or housekeeping, the filesystem might be
log-structured so it's reading or writing bits of 5 different files,
the upper layer might be a swap partition or something more exotic, it
might be part of a disk check, there might be software RAID between
the filesystem and hardware, etc.

Why do you need this data and what are you trying to accomplish here?

> I looked into scsi_cmd structure and all the structures it references
> to. Also I used ftrace to find on which level of abstraction inode
> disappear but without any luck. Could you please say to me where I
> could find the lowest level where inode is still present and the best
> way how to pass it throughout linux io stack to the ufshcd driver?
> Frankly speaking I need not struct inode as a whole but just its
> number, so using reserved or unused fields of existing structures is
> appropriate.

The inode number is part of the filesystem so it wouldn't appear below
that layer.

Thanks,

-- 
Julian Calaby

Email: julian.cal...@gmail.com
Profile: http://www.google.com/profiles/julian.calaby/

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