diff options
| author |   Dmitry Monakhov <dmonakhov@openvz.org> | 2012-09-29 00:55:23 -0400 |
|---|---|---|
| committer |   Theodore Ts'o <tytso@mit.edu> | 2012-09-29 00:55:23 -0400 |
| commit | 1c9114f9c0f10f58dd7e568a7152025af47b27e5 (patch) | |
| tree | 1c9fd2798fe34047ffd14030364d71ca64533b55 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | ext4: serialize dio nonlocked reads with defrag workers (diff) | |
| download | linux-dev-1c9114f9c0f10f58dd7e568a7152025af47b27e5.tar.xz linux-dev-1c9114f9c0f10f58dd7e568a7152025af47b27e5.zip | |
ext4: serialize unlocked dio reads with truncate
Current serialization will works only for DIO which holds
i_mutex, but nonlocked DIO following race is possible:
dio_nolock_read_task truncate_task
->ext4_setattr()
->inode_dio_wait()
->ext4_ext_direct_IO
->ext4_ind_direct_IO
->__blockdev_direct_IO
->ext4_get_block
->truncate_setsize()
->ext4_truncate()
#alloc truncated blocks
#to other inode
->submit_io()
#INFORMATION LEAK
In order to serialize with unlocked DIO reads we have to
rearrange wait sequence
1) update i_size first
2) if i_size about to be reduced wait for outstanding DIO requests
3) and only after that truncate inode blocks
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions