Hello,
I was looking into what protects CIFS from races between hole punching and
operations like page fault or readahead and AFAICT there's nothing to
prevent a race like:
CPU1 CPU2
smb3_fallocate()
smb3_punch_hole()
truncate_pagecache_range()
filemap_fault()
- loads old data into the
page cache
SMB2_ioctl(..., FSCTL_SET_ZERO_DATA, ...)
And now we have stale data in the page cache and if the page gets later
dirtied and written out, even persistent data corruption. Is there anything
I'm missing?
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
