• Chao Yu's avatar
    f2fs: avoid stucking GC due to atomic write · 2ef79ecb
    Chao Yu authored
    f2fs doesn't allow abuse on atomic write class interface, so except
    limiting in-mem pages' total memory usage capacity, we need to limit
    atomic-write usage as well when filesystem is seriously fragmented,
    otherwise we may run into infinite loop during foreground GC because
    target blocks in victim segment are belong to atomic opened file for
    long time.
    
    Now, we will detect failure due to atomic write in foreground GC, if
    the count exceeds threshold, we will drop all atomic written data in
    cache, by this, I expect it can keep our system running safely to
    prevent Dos attack.
    
    In addition, his patch adds to show GC skip information in debugfs,
    now it just shows count of skipped caused by atomic write.
    Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
    Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
    2ef79ecb
file.c 70.4 KB