After the FUSE daemon crashes, the fuse mount point becomes inaccessible. In some production environments, a watchdog daemon is used to preserve the FUSE connection's file descriptor (fd). When the FUSE daemon crashes, a new FUSE daemon is started and takes over the fd from the watchdog daemon, allowing it to continue providing services. However, if any inflight requests are lost during the crash, the user process becomes stuck as it does not receive any replies. To resolve this issue, this patchset introduces a sysfs API that enable resending these pending requests to the FUSE daemon again, allowing the stuck user process to recover. When using the resend API, FUSE daemon needs to ensure proper recording and avoidance of processing duplicate non-idempotent requests to prevent potential consistency issues. The high bit of the fuse request id is utilized for indicating the resend request. --- v1->v2: - remove flush sysfs API in the original mail - add using high bit of request ID for indicating resend requests - add wakeup in fuse_resend_pqueue() Peng Tao (1): fuse: Introduce sysfs API for resend pending reque Zhao Chen (1): fuse: Use the high bit of request ID for indicating resend requests fs/fuse/control.c | 20 +++++++++++ fs/fuse/dev.c | 70 ++++++++++++++++++++++++++++++++++++--- fs/fuse/fuse_i.h | 5 ++- fs/fuse/inode.c | 3 +- include/uapi/linux/fuse.h | 11 ++++++ 5 files changed, 103 insertions(+), 6 deletions(-) -- 2.32.0.3.g01195cf9f
