diff options
| author | Brian Behlendorf <[email protected]> | 2014-12-19 12:57:54 -0800 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2014-12-22 09:31:56 -0800 |
| commit | 74328ee18f94d27f9c802d29fdd311018dab2adf (patch) | |
| tree | e1c45efc24bf65c579832175d193d5c4c18df2d8 /include/sys/trace.h | |
| parent | 2d9d57b0fbe17b56a1bdd09505400144778cb189 (diff) | |
Fix zfs_putpage() lock inversion
There exists a lock inversions involving the zfs range lock and the
individual page writeback bits which can result in a deadlock. To
prevent this we must always manipulate the writeback bit while
holding the range lock. The exact deadlock is as follows:
------ Process A ------ ------ Process B ------
zpl_writepages zpl_fallocate
write_cache_pages zpl_fallocate_common
zpl_putpage zfs_space
zfs_putpage (set bit) zfs_freesp
zfs_range_lock (wait on lock) zfs_free_range (take lock)
[has not yet initiated I/O, truncate_inode_pages_range
the bit will not be cleared] wait_on_page_writeback (wait on bit)
Signed-off-by: Brian Behlendorf <[email protected]>
Signed-off-by: Tim Chase <[email protected]>
Signed-off-by: Richard Yao <[email protected]>
Issue #2976
Diffstat (limited to 'include/sys/trace.h')
0 files changed, 0 insertions, 0 deletions