Hi! On 4/28/22 19:18, Daeho Jeong wrote: > From: Daeho Jeong <[email protected]> > > Current atomic write has three major issues like below. > - keeps the updates in non-reclaimable memory space and they are even > hard to be migrated, which is not good for contiguous memory > allocation. > - disk spaces used for atomic files cannot be garbage collected, so > this makes it difficult for the filesystem to be defragmented. > - If atomic write operations hit the threshold of either memory usage > or garbage collection failure count, All the atomic write operations > will fail immediately. > > To resolve the issues, I will keep a COW inode internally for all the > updates to be flushed from memory, when we need to flush them out in a > situation like high memory pressure. These COW inodes will be tagged > as orphan inodes to be reclaimed in case of sudden power-cut or system > failure during atomic writes. > > Signed-off-by: Daeho Jeong <[email protected]> > --- > v2: removed inmem tracepoints. changed page flush timing. fixed hole > handling. > v3: removed unused atomic related page flag. > --- > fs/f2fs/data.c | 180 +++++++++++------ > fs/f2fs/debug.c | 12 +- > fs/f2fs/f2fs.h | 33 +--- > fs/f2fs/file.c | 48 ++--- > fs/f2fs/gc.c | 27 +-- > fs/f2fs/inode.c | 3 +- > fs/f2fs/namei.c | 28 ++- > fs/f2fs/node.c | 4 - > fs/f2fs/node.h | 1 - > fs/f2fs/segment.c | 380 ++++++++++++------------------------ > fs/f2fs/segment.h | 4 +- > fs/f2fs/super.c | 6 +- > include/trace/events/f2fs.h | 22 --- > 13 files changed, 302 insertions(+), 446 deletions(-)
This patch fixes the bug reported at: LINK: https://syzkaller.appspot.com/bug?id=50ac8d898487cade14315bf673e8d74fd4716ecf One may find the strace log at: LINK: https://syzkaller.appspot.com/text?tag=CrashLog&x=11f5de2ac80000 and the C reproducer at: LINK: https://syzkaller.appspot.com/text?tag=ReproC&x=111facdcc80000 The patch does not apply cleanly on stable/linux-5.15.y. Backporting the patch is a bit risky for me as I'm not familiar with f2fs. I'm seeking for some guidance. Is there a plan to backport this patch to Linux stable? If not, shall I try to backport it? Would you advise me to try to find all the prerequisite patches for this patch to apply cleanly on stable/linux-5.15.y, or just to fix the conflicts? Thanks, ta _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
