(pre-stable) ext4: fix freeze deadlock under IO
BugLink: http://bugs.launchpad.net/bugs/595489 Commit 6b0310fb caused a regression resulting in deadlocks when freezing a filesystem which had active IO; the vfs_check_frozen level (SB_FREEZE_WRITE) did not let the freeze-related IO syncing through. Duh. Changing the test to FREEZE_TRANS should let the normal freeze syncing get through the fs, but still block any transactions from starting once the fs is completely frozen. I tested this by running fsstress in the background while periodically snapshotting the fs and running fsck on the result. I ran into occasional deadlocks, but different ones. I think this is a fine fix for the problem at hand, and the other deadlocky things will need more investigation. Reported-by: Phillip Susi <psusi@cfl.rr.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Stefan Bader <stefan.bader@canonical.com> (cherry-picked from commit 437f88cc031ffe7f37f3e705367f4fe1f4be8b0f upstream) Acked-by: Tim Gardner <tim.gardner@canonical.com> Acked-by: Steve Conklin <steve.conklin@canonical.com> Acked-by: Andy Whitcroft <andy.whitcroft@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
parent
01f3e663
Please register or sign in to comment