• Al Viro's avatar
    fix O_SYNC|O_APPEND syncing the wrong range on write() · d311d79d
    Al Viro authored
    It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support)
    when sync_page_range() had been introduced; generic_file_write{,v}() correctly
    synced
    	pos_after_write - written .. pos_after_write - 1
    but generic_file_aio_write() synced
    	pos_before_write .. pos_before_write + written - 1
    instead.  Which is not the same thing with O_APPEND, obviously.
    A couple of years later correct variant had been killed off when
    everything switched to use of generic_file_aio_write().
    
    All users of generic_file_aio_write() are affected, and the same bug
    has been copied into other instances of ->aio_write().
    
    The fix is trivial; the only subtle point is that generic_write_sync()
    ought to be inlined to avoid calculations useless for the majority of
    calls.
    Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
    d311d79d
file.c 15.6 KB