There are situations where fuse servers can become unresponsive or stuck, for example if the server is in a deadlock. Currently, there's no good way to detect if a server is stuck and needs to be killed manually. This patchset adds a timeout option where if the server does not reply to a request by the time the timeout elapses, the connection will be aborted. This patchset also adds two dynamically configurable fuse sysctls "default_request_timeout" and "max_request_timeout" for controlling/enforcing timeout behavior system-wide. Existing systems running fuse servers will not be affected unless they explicitly opt into the timeout. v10: https://lore.kernel.org/linux-fsdevel/20241214022827.1773071-1-joannelkoong@xxxxxxxxx/ Changes from v10 -> v11: * Refactor check for request expiration (Sergey) * Move workqueue cancellation to earlier in function (Jeff) * Check fc->num_waiting as a shortcut in workqueue job (Etienne) v9: https://lore.kernel.org/linux-fsdevel/20241114191332.669127-1-joannelkoong@xxxxxxxxx/ Changes from v9 -> v10: * Use delayed workqueues instead of timers (Sergey and Jeff) * Change granularity to seconds instead of minutes (Sergey and Jeff) * Use time_after() api for checking jiffies expiration (Sergey) * Change timer check to run every 15 secs instead of every min * Update documentation wording to be more clear v8: https://lore.kernel.org/linux-fsdevel/20241011191320.91592-1-joannelkoong@xxxxxxxxx/ Changes from v8 -> v9: * Fix comment for u16 fs_parse_result, ULONG_MAX instead of U32_MAX, fix spacing (Bernd) v7: https://lore.kernel.org/linux-fsdevel/20241007184258.2837492-1-joannelkoong@xxxxxxxxx/ Changes from v7 -> v8: * Use existing lists for checking expirations (Miklos) v6: https://lore.kernel.org/linux-fsdevel/20240830162649.3849586-1-joannelkoong@xxxxxxxxx/ Changes from v6 -> v7: - Make timer per-connection instead of per-request (Miklos) - Make default granularity of time minutes instead of seconds - Removed the reviewed-bys since the interface of this has changed (now minutes, instead of seconds) v5: https://lore.kernel.org/linux-fsdevel/20240826203234.4079338-1-joannelkoong@xxxxxxxxx/ Changes from v5 -> v6: - Gate sysctl.o behind CONFIG_SYSCTL in makefile (kernel test robot) - Reword/clarify last sentence in cover letter (Miklos) v4: https://lore.kernel.org/linux-fsdevel/20240813232241.2369855-1-joannelkoong@xxxxxxxxx/ Changes from v4 -> v5: - Change timeout behavior from aborting request to aborting connection (Miklos) - Clarify wording for sysctl documentation (Jingbo) v3: https://lore.kernel.org/linux-fsdevel/20240808190110.3188039-1-joannelkoong@xxxxxxxxx/ Changes from v3 -> v4: - Fix wording on some comments to make it more clear - Use simpler logic for timer (eg remove extra if checks, use mod timer API) (Josef) - Sanity-check should be on FR_FINISHING not FR_FINISHED (Jingbo) - Fix comment for "processing queue", add req->fpq = NULL safeguard (Bernd) v2: https://lore.kernel.org/linux-fsdevel/20240730002348.3431931-1-joannelkoong@xxxxxxxxx/ Changes from v2 -> v3: - Disarm / rearm timer in dev_do_read to handle race conditions (Bernrd) - Disarm timer in error handling for fatal interrupt (Yafang) - Clean up do_fuse_request_end (Jingbo) - Add timer for notify retrieve requests - Fix kernel test robot errors for #define no-op functions v1: https://lore.kernel.org/linux-fsdevel/20240717213458.1613347-1-joannelkoong@xxxxxxxxx/ Changes from v1 -> v2: - Add timeout for background requests - Handle resend race condition - Add sysctls Joanne Koong (2): fuse: add kernel-enforced timeout option for requests fuse: add default_request_timeout and max_request_timeout sysctls Documentation/admin-guide/sysctl/fs.rst | 25 ++++++++ fs/fuse/dev.c | 85 +++++++++++++++++++++++++ fs/fuse/fuse_i.h | 32 ++++++++++ fs/fuse/inode.c | 35 ++++++++++ fs/fuse/sysctl.c | 14 ++++ 5 files changed, 191 insertions(+) -- 2.43.5
